Some basic stuff (mostly for the non-economists)

As a student of “economics”, I’m pretty sure I’ve had more courses dealing with stuff like this (and of course stuff a bit harder) than I’ve had courses about how ‘the economy’ supposedly ‘works’.

In related news, semester started yesterday so I might update a bit less frequently in the time to come. We’ll see how it goes.


August 31, 2011 Posted by | education, Khan Academy, knowledge sharing, Mathematics, Statistics | Leave a comment

A few notes on (meta)rationality

So, let’s say you think policy X is optimal and policy Y is not. Or perhaps religion X is true and religion Y is not. Or you know something about subject X and you think you’re right, even though other people disagree. Now, if you’re like most people, you haven’t taken a closer look at the data.

Not necessarily, mind you, the policy data or the data supporting or questioning the religious ideas. Most people use some form of this type of data in their arguments, perhaps not as much because they find the data convincing but rather because they think they need to justify their beliefs somehow, and if you say that ‘policy X will result in more poor people’, or some kind of stuff like that, odds are that added information makes your position look more convincing to the opponent than if you chose not to say it. But the ‘unemployment will go up 2,4 % if policy Y is implemented’ is not the kind of data I was thinking about here. I was thinking about the data on who thinks what. Background variables. Do people who think X have stuff in common which might explain why they think the way they do? It’s an important part of understanding the subject – if your age or gender affects your opinion on the subject matter, disregarding those factors when explaining why you think the way you do leads to a potentially huge omitted variables bias. In short, it can cause you to deceive yourself about which factors have been important in the formation and development of your views. You think that you think X because of A and B (‘unemployment will go up 2,4 %’); but really it’s more a mixture of A, B, C and D.

People make arguments constructed like this: I think/like/prefer X because Y, where Y is some variable that pertains somewhat to the validity of the arguments under evaluation. Like, say, unemployment. Maybe I think the other guy’s argument is faulty or incomplete. Perhaps A (‘taxes’) is more important to me than B (‘environmental safety measure Q’). On net, the amount of supporting arguments in favor of X is higher than the amount of arguments in favor of Y. Things like that.

Here are some other things you might say in an argument – I don’t think most people bring up stuff like this very often, and when they do it’s mostly the characteristics of the opponent in the argument that gets the attention. To bring up this kind of stuff in an argument can go from being considered irrelevant to the matter in question to being considered an unjustifiable attempt to smear the opponent. The funny thing is that variables and related inferences like the ones below sometimes have extremely high explanatory power when you want to estimate what individual A thinks about subject X. We know this stuff matters a lot, but people really like to pretend it doesn’t and it’s often considered cynical or perhaps downright rude to bring it up in conversation. Here are some of them. Of course no one of these will have 100 percent explanatory power either, so I urge you not to reject arguments like these out of hand because they only explain part of the variation in the data – think of them as variables you might decide to estimate in an econometric model while trying to explain, say, the distribution of the opinion variable Z:

‘I think X because my mother and father had an academic education.’ ‘My parents (priest/teacher/big brother) told me X and I’ve been taught by them not to question their authority.’ ‘Because I was born in country C instead of country D.’ (related – articles like this one is part of why I keep coming back to tvtropes even though I tell myself not to) ‘Because I was born in the year XXX instead of the year XXY.’ ‘Because I have a girlfriend and a child.’ ‘Because I’m XX years old instead of XY years old’ – or a more specific example: ‘Because I’m 55 and policy X will benefit me personally.’ ‘Most of my friends think X is better/true.’ ‘If I support policy X I will obtain a higher status among my peers, even though at a cursory glance it might look like policy X will hurt me personally.’ ‘Supporting (/cause) X makes me feel special and I like to feel special.’ ‘Because I’m (fe)male.’ ‘Because I like my job and have an optimistic frame of mind.’ ‘I spent a lot of time thinking about these things because I derive status from winning arguments because I think it makes me look smart. If the other guy is perceived to be right and win the argument I won’t look smart.’ ‘I haven’t really thought about this at all and I don’t know what to think, but I’m supposed to participate in arguments like these and provide an opinion so I’ll just say X because it’s the first thing that popped into my mind when they asked me. Also, most people I care about seem to support X.’ ‘I have to support Y because A supported X and I don’t like/trust A’s.’ ‘People with a high education and income tend to believe/support X so if I support/believe X my status will increase.’ ‘I heard argument X before I heard argument Y.’ ‘A supports Y. If I support X then A will become offended and an unpleasant situation might arise. I will therefore support Y.’

Part of why people don’t look at data like this is that it’s often impossible to come by in specific cases and it’s usually very difficult to quantify effects like these. There’s a lot of impact heterogeneity as well when it comes to the impact of specific variables on individuals and you easily risk committing the ecological fallacy without thinking about it if you try to include variables like these in your model of the opinion forming mechanism of your opponent in a debate. Maybe the inclusion of such variables do not really make matters more clear, perhaps the opposite, perhaps some of the included variables are irrelevant. Do I think X because the cute girl in the lab thinks X, because my parents disagrees, because my friends who introduced me to the subject all think X or because of the latest employment figures? Who knows? But we like to pretend that we do know, and that our motives are pure – only the employment figures matter. If somebody cedes the point that that stuff also matters, then even though there’s an effect it still isn’t something important that should merit our attention; quite the opposite, we ought to focus on the employment figures. An interesting thing is also that in some cases it’s very easy to come by the numbers, and even when it is this stuff tends to be ignored. For example, 90 % of all Egyptians are identified as Muslim, so if you grow up in Egypt, there’s a very high likelihood that you’ll be born and raised by people who think the Muslim religion is the ‘true one’ – whereas if you’re on the other hand born in the US there’s something like a less than 1 % chance that you’ll be born and raised by Muslim parents, and there’s a much, much higher chance that you’ll be born and raised by people who consider themselves christians. There’s a very high correlation between the religious views of children and that of their parents.

I tend to think that people who spend time thinking about this kind of stuff are usually not much harder to deceive than people who do not. We’re all rational when it suits us, but when that’s the case is most often not something we spend much time thinking consciously about. Most people pretend to be rational when you question their rationality by bringing up ‘the other stuff’; some are just better pretenders than others.

August 29, 2011 Posted by | disagreement, Philosophy, politics, rambling nonsense | Leave a comment





Image credit: Wikipedia.


“By definition, juggling requires at least one more ball than there are hands. So, with 2 hands, omega has a minimum value of 0.5, when b = 3 and r = 1.

Newtonian physics provides some equations that apply to thrown objects:
Vh = F / f
Vv = sqrt(2 * g * H)
H = (Vv ^ 2) / 2 / g

If the throws and catches are assumed to occur at the same height, we can solve for the flight time, f, and substitute it into the other equations. As a result, we get some useful equations:
f = sqrt(8 * H / g)
Vv = g * f / 2
H = g * (f^2) / 2 = g * [(tau * omega)^2] / 8

These equations tell us that to double the flight time, you must double the initial throw velocity which means quadrupling the throw height.

Graph 1: Throw Height as a Function of tau and omega (assuming throw and catch positions at the same height, g = 9.81 m/s/s)


The Optimal Cascade
The shape and relative positions of the arcs are defined by the equations for P and the optimal arc equations. We now must determine the optimal endpoints of the arcs, which will be the throw and catch positions. We will not assume throws and catches are at the same height. Define the following new variables:
E = dwell distance = distance between catch position and throw position
theta = dwell angle

Assume we are given two parabolas in a cascade, and the values for Vh, F, and P are also given. We would like to find the exact throw and catch positions on these parabolas that minimizes the distance between throw and catch. (The equations start to get messy here, so I’ll just summarize the method and the results.) First, find the optimal value of theta to minimize the dwell distance, E. This is done by finding an equation for E in terms of the given quantities and theta, and setting the derivative with respect to theta, dE/d(theta) = 0. The result is:
tan(theta) = 2 * Vh * Vh / g / F .

Substituting this value back into equations for E and H, we get the following results:
E = P * cos(theta) .
This means the distance the hands must move, E, is slightly less than P but E is still always greater than the diameter of a ball, D. The result for H is:
H = {F + [P * sin(theta) * sin(theta)]}^2 / [4 * F * tan(theta)]
As mentioned earlier, if theta is small, H can be approximated with:
H = g * f * f / 8 .

There is a limit to how low you can make an optimal cascade. The balls from one arc must graze the balls from the other arc. The limit is reached when, at the instant each ball is thrown, it grazes the previously thrown ball from the other hand. Here is a summary of how to find the equation for this limit. First, write an equation for the distance between two consecutive throws from opposite hands. By setting the time derivative of this distance = 0, we find the time at which the distance between the balls is minimized and, in an optimal pattern, they are touching. By setting this time = 0, we get an equation for patterns where balls are grazing at the instant of the throw. The result, included for completeness, is: 2v(h)(F-E*cosϕ-D/2)+gτ^2/4(v(v)-gτ/4)=0″

(more here)




” Average linear size of areas with uniform sign of mean curvature for elastic and elasto-plastic sheets of size L/h=250, 500 and 1,000. In a crumpled state (R<0.4R0), this size describes the characteristic size of facets and ridges in the sheet. b, The total energy of elastic and elasto-plastic sheets of size L/h=250, 500 and 1,000, scaled by 1/(L/h)1/3. Transitions in the energy of the elastic sheets at R~0.75R0 and R~0.4R0 indicate the formation of a cone and the end of a single-cone regime, respectively. The plots shown are averages of three simulations, and the yield point of the elasto-plastic sheets is Y^(1/σ)=0.01.” […]

In elasto-plastic sheets, the situation is more complicated. It is evident from Fig. 3 that their average linear facet size and energy scale similarly as a function of compression to the elastic sheets. There are however differences in the two crumpling processes, which arise at early phases of crumpling. In vertices in particular, plastic deformations appear already for R/R0 close to unity. An elasto-plastic sheet is not able to transform into a cone necessary for a folding type of initial deformations, and large numbers of vertices and ridges appear soon after crumpling begins. This becomes increasingly pronounced for increasing L/h so that the relative facet diameter then decreases as shown in Fig. 3a. It is evident from this figure that the average ridge length scales now as mean(x)/L=f(L/h)g(R/R0), where function g(z) has a power-law form in a fairly large range of the argument. It is difficult to determine by simulations a functional form for f(z). The above scaling form means however that elasto-plastic sheets of different L/h can only have the same average (relative) ridge length for different degrees of compression. Consequently, the similarity of ridge patterns found for crumpled elastic sheets does not appear in elasto-plastic sheets. The lack of such similarity is also evident in the L/h-dependent distributions of the linear facet size in elasto-plastic sheets (Fig. 4d): sheet thickness must be scaled together with the other spatial dimensions to preserve the form of the distribution. The distributions of linear facet size are now well fitted by lognormal distributions, found previously for experimental facet size”

Much more here.




This and this.






“Pressure is an effect which occurs when a force is applied on a surface. Pressure is the amount of force acting on a unit area. The symbol of pressure is P […] Mathematically:

P = F/A or P = dFn/dA


P is the pressure,
F is the normal force,
A is the area.

Pressure is a scalar quantity. It relates the vector surface element (a vector normal to the surface) with the normal force acting on it. The pressure is the scalar proportionality constant that relates the two normal vectors:

dF(n) = -dA = -PndA

The minus sign comes from the fact that the force is considered towards the surface element, while the normal vector points outwards.” (link)

“Nutritional value per 100 g (3.5 oz) :
Energy 218 kJ (52 kcal)
Carbohydrates 13.81 g
– Sugars 10.39 g
– Dietary fiber 2.4 g
Fat 0.17 g
Protein 0.26 g
Water 85.56 g
Vitamin A equiv. 3 μg (0%)
Thiamine (Vit. B1) 0.017 mg (1%)
Riboflavin (Vit. B2) 0.026 mg (2%)
Niacin (Vit. B3) 0.091 mg (1%)
Pantothenic acid (B5) 0.061 mg (1%)
Vitamin B6 0.041 mg (3%)
Folate (Vit. B9) 3 μg (1%)
Vitamin C 4.6 mg (6%)
Calcium 6 mg (1%)
Iron 0.12 mg (1%)
Magnesium 5 mg (1%)
Phosphorus 11 mg (2%)
Potassium 107 mg (2%)
Zinc 0.04 mg (0%)”


Yeah, I know:

A big part of why we keep things simple is because otherwise we’d have died out long ago. And our brains aren’t big enough to understand all that stuff anyway, even if there were time to figure it all out, which there’s not.

But things don’t get any simpler by us trying to make them so. Even very basic stuff usually tends to be horribly complicated once you start to think about it. Once in a while you can actually convince yourself that this existence-stuff we have going on is really quite fantastic.

August 27, 2011 Posted by | Physics, Random stuff, Science | 1 Comment

Promoting the unknown, a continuing series

August 26, 2011 Posted by | Music | Leave a comment

Sygdomsforebyggelse (iii)

Der er mange ting herunder som nærmest alle ‘burde vide’, men som jeg er sikker på mange ikke ved. Folk er ikke gode til at (bestemme sig for faktisk at bruge tid på at…) evaluere abstrakte risici, især ikke risici som relaterer til begivenheder som ofte ligger et pænt stykke ude i fremtiden. Det gælder sundhed, det gælder pension, det gælder så mange ting. Denne helt nye artikel fra berlingske understreger problemet at i al fald mange kvinder ikke evaluerer/estimerer konsekvenserne af helbredsrelateret risikoadfærd korrekt:

»Typisk mener kvinder, at åreforkalkningssygdomme skyldes overvægt, og mange tror, at et mindre vægttab vil ændre betydeligt på risikoen for at udvikle en hjertekarsygdom. Men intet kunne være mere forkert. Det er faktisk ni gange så farligt at ryge, som at have lidt ekstra kilo på sidebenene,« fortæller formanden i Hjerteforeningen Peter Clemmesen, som til dagligt er overlæge på Rigshospitalet.

Alligevel nævner hele 40 procent af de adspurgte kvinder i undersøgelsen ikke rygning som en af de største risikofaktorer.

Jeg var mildt sagt overrasket over dette resultat, og når man kan få den slags respons så er det næsten lige før man kan overbevise sig selv om, at det er lige meget, hvor meget man informerer. Men altså, jeg gør det alligevel. Jeg har nævnt det før, men husk på at bogen er fra 2001. Nogle passager fra bogen:

i. “Apopleksi er en hyppig sygdom. Med en incidens på ca. 2/1.000/år betyder det at hver syvende dansker vil blive ramt af sygdommen. Apopleksisygdommen er ganske alvorlig. Det er den tredje hyppigste dødsårsag i den vestlige verden og den hyppigste årsag til invaliditet i den voksne befolkning.
Apopleksi er en sygdom der først og fremmest rammer ældrebefolkningen; 85 % af de ramte er over 60 år, og 35 % er over 80 år. Da andelen af ældre i befolkningen vil tage stærkt til i de kommende årtier, vil sygdommens samfundsmæssige betydning vokse tilsvarende. Mænds risiko for at blive ramt af sygdommen er dobbelt så stor som kvinders. […] Det er den dyreste sygdom i det danske sundhedsvæsen idet ca. 5 % af de samlede udgifter til hospitalsdrift i Danmark bruges på apopleksisygdommen.”

Den primære årsag til de høje omkostninger er lang indlæggelsestid. Jeg ved ikke om der er sket fremskridt på dette område siden da.

“De primærprofylaktiske foranstaltninger [se foregående post] retter sig først og fremmest mod livsstilsændringer idet hypertension, tobaksrygning, kostsammensætning, sukkersyge og iskæmisk hjertesygdom er årsag til de fleste apopleksier. […] Man regner med at op mod halvdelen af alle apopleksier skyldes hypertension. Risikoforøgelsen gælder begge køn, alle aldre (også de ældste), alle grader af hypertension, og den gælder personer med isoleret diastolisk såvel som systolisk hypertension. I gennemsnit er risikoen for apopleksi hos personer med hypertension tre til fire gange større end i normalbefolkningen, men den er stigende med stigende blodtryk, og for personer med svær hypertension er risikoen således ti gange højere end normalbefolkningen. […] Selv om sammenhængen mellem hypertension og apopleksi er stærk – stærkere end for hjertesygdommes vedkommende – er antallet af behandlede relativt beskedent. […] Kun ca. en fjerdedel af alle med hypertension er i sufficient behandling.”

Igen, husk på at dette er 2001-tal. Man kan håbe situationen er bedret siden da, men jeg ved ikke hvordan billedet er i dag.

“Tobaksrygning er næst efter hypertension den mest betydende risikofaktor for apopleksi. Den andel af apopleksi der kan tilskrives rygning, er et sted mellem 15 og 35 %. I gennemsnit forøger tobaksrygning risikoen for apopleksi to til tre gange, og risikoen er dosisafhængig. Hos personer der ryger mere end 20 cigaretter dagligt, er risikoen for apopleksi således forøget næsten seks gange i forhold til risikoen hos en ikke-ryger. Rygeophør nedsætter omgående risikoen.” […] “Hjertesygdom øger risikoen for apopleksi to til fire gange, og mere end 85 % af apopleksipopulationen lider af en eller anden form for hjertesygdom. Tilstedeværelse af atrieflimren alene øger risikoen fem til seks gange. […] Diabetes mellitus er forbundet med en risiko for apopleksi der er to til tre gange større end ikke-diabetiske personers, og diabetes er ansvarlig for 2-5 % af alle apopleksier.”

ii. “Hjerte-kar-sygdomme (kardiovaskulære sygdomme) er en fællesbetegnelse for den store gruppe af sygdomme der er årsag til de fleste dødsfald, over en tredjedel, og en meget betydelig sygelighed i Danmark. Den største gruppe af hjerte-kar-sygdomme er de aterosklerotiske sygdomme der er forårsaget af aterosklerose (åreforkalkning). Aterosklerose af hjertets kranspulsårer er den hyppigste form for aterosklerose; det kaldes koronar aterosklerose og er den væsentligste årsag til iskæmisk hjertesygdom. Andre pulsårer (arterier) kan imidlertid også udvikle aterosklerotiske læsioner med symptomgivende sygdom til følge. Det er især i hjernen, nyrerne og benene. Halvdelen af hjerte-kar-dødsfaldene i Danmark skyldes iskæmisk hjertesygdom, en fjerdedel skyldes sygdomme i hjernens kar (cerebrovaskulære sygdomme) og den sidste fjerdedel er dødsfald som følge af øvrige hjertesygdomme eller sygdomme i blodårer. […] Klinisk vil koronar aterosklerose ofte være meget fremskreden før den giver sig til kende i form af et akut iskæmisk syndrom eller som mere kroniske og ofte anstrengelsesudløste symptomer. […]

Rygning virker synergistisk sammen med de øvrige risikofaktorer, og det er beregnet at 30-40 % af hjertedødsfaldene hvert år kan tilskrives tobaksrygning. Danske undersøgelser har vist at kvinders risiko er relativt større end mænds ved samme tobaksforbrug. […]
Fysisk inaktivitet øger risikoen for iskæmisk hjertesygdom to til tre gange og medvirker også til en øget risiko for overvægt, hypertension og diabetes. […]
Forhøjet blodtryk er klart associeret med en øget forekomst af iskæmisk hjertesygdom. […]
Dyslipidæmi er en samlet betegnelse for alle typer lipidforstyrrelser i blodet og er en meget vigtig risikofaktor for udvikling af iskæmisk hjertesygdom. […] Der foreligger adskillige kliniske undersøgelser som viser at en reduktion af kolesterol, og især LDL-kolesterol, ved kostomlægning og supplerende medicinsk behandling kan nedsætte risikoen for iskæmisk hjertesygdom. […] Den medicinske behandling kan imidlertid nedsætte risikoen for iskæmisk hjertesygdom med 25-30 %. […]
det er velkendt at patienter med type-2 diabetes fremtræder med multiple kardiovaskulære risikofaktorer der som regel er til stede på diagnosetidspunktet. […] Behandlingen af hyperglykæmien alene kan ikke forventes at normalisere den øgede risiko.”

iii. “Man kan sige at [lungekræft] i dag har karakter af en folkesygdom idet 5 % af den danske befolkning på et eller andet tidspunkt i deres liv rammes af sygdommen […] Der dør ca. 3.500 mennesker om året af lungekræft i Danmark, og sygdommen er den kræftform som dræber flest, både mænd og kvinder. […] Cirka ni ud af ti tilfælde af lungekræft skyldes tobaksrygning, og lungekræft er en sjælden sygdom blandt aldrig-rygere. […] Den del af befolkningen som får lungekræft og som aldrig har været dagligrygere, er ca. 0,5 % mens næsten 20 % af storcigaretrygerne ender med at dø af sygdommen”

August 26, 2011 Posted by | bøger, Data, Sundhed | Leave a comment

Sygdomsforebyggelse (ii)

Første post om bogen her. Jeg har besluttet mig for at bruge mindst 2-3 posts mere (inklusiv denne?) på bogen, for der er faktisk en masse interessant stof gemt i den.

Passager fra værket og enkelte kommentarer. Alle afsnit i denne post er fra bogens første del – den jeg var mindst begejstret for (med undtagelse af kap. 7, pkt. iv herunder omhandler dette kapitel):

i. Nedenstående er fra kapitel 2, Sygdomsforebyggelse i et antropologisk og historisk perspektiv, et lidt ukarakteristisk kapitel som for så vidt i langt højere grad omhandler medicinsk historie end forebyggelse:

“Salernoklosteret syd for Napoli i Italien oprettedes i det syvende århundrede og blev med tiden en berømt lægeskole og et forbillede for de senere universiteter i Europa. […] Salernoskolen byggede på den gamle hippokratiske lære om legemets fire væsker: 1) blodet i årerne, 2) slimen i hjernen og lungerne, 3) den gule galde i leveren og 4) den sorte galde i milten. Sygdom indtraf hvis et bestemt indbyrdes forhold eller væskernes kvalitet ændredes. Væskernes kvalitet var følgende: 1) blodet var varmt og fugtigt, 2) slimen var kold og fugtig, 3) den gule galde var varm og tør og 4) den sorte galde var kold og tør. Når nogen blev syg, kunne lægen gennem undersøgelse af urin, puls og vejrtrækning afgøre hvilke af de fire legemsvæsker der var i overvægt, og bestemme behandlingen ud fra dette. De fire væsker var desuden relateret til de fire forskellige temperamenter en personlighed kunne bestå af: sanguinikeren, flegmatikeren, kolerikeren og melankolikeren. […]

En opdeling af det menneskelige legeme blev sat i forbindelse med de 12 stjernetegn. Det havde betydning for åreladningen, som skulle foregå på de steder på kroppen der svarer til jordens stilling i forhold til dyrekredsen. Åreladning har imidlertid ikke kun været anvendt i forbindelse med sygdom, men også som beskyttelse mod sygdom, dvs. forebyggende. For eksempel havde visse munke pligt til at lade sig årelade fem gange om året. […] Mens Salerneskolens lære var for de få, de lærde, var folkemedicinen, troen på magi, kloge mænd og koner, det eneste tilgængelige middel mod sygdom for størstedelen af middelalderens mennesker. […]

Samtidig med at man i middelalderen var overbevist om at et godt helbred var afhængigt af vedligeholdelse eller genoprettelse af balancen mellem kropsvæskerne, bl.a. ved hjælp af indtagelse af lægeurter, blev alle madvarer karakteriseret i overensstemmelse med de fire værdier eller kvalitetsgrader. Det vil sige efter om deres essens var varm eller kold, tør eller fugtig. For eksempel passede rødvin ikke med et hedt temperament fordi rødvins essens var varm, og derfor anbefaledes kold hvidvin i stedet. […]

I begyndelsen af 1900-tallet rapporteres over 50 % af børnene at have forskellige grader af engelsk syge, mange dog blot i form af tandemaljeforstyrrelser. Levertran blev det 20. århundredes forebyggende behandling mod sygdommen, og samtidig blev forskellige fødemidler, bl.a. margarine og mel, tilsat D-vitamin.”

ii. “Indlagte patienterne [ sic ] er en gruppe der er særligt motiverede for forebyggelse fordi de kommer i kontakt med sygehusvæsenet når livet står på spil. Lægen kan med en saglig formidling af sin viden gøre en stor indsats for at få patienten til at ændre livsstil og dermed forebygge sygdomme og recidiver […]. Lægen og sygeplejersken møder patienten i en situation hvor den sundhedsskadelige livsstil har vundet en, måske foreløbig, sejr over fysikken. Og det er veldokumenteret at viden om hensigtsmæssig livsstil ikke er tilstrækkeligt til at få mennesker til at ændre livsstil. Der skal en dybere motivation til, og den kan befordres via holdningsbearbejdelse.”

iii. Fra “Myndighederne overvåger i stigende omfang borgernes sundhed gennem helbredskontrol og screening. En screening vedrører altid en bestemt sygdom eller gruppe af sygdomme, og formålet er enten at øge chancen for helbredelse for sygdommen, eller at forebygge at en forhøjet risiko for at blive syg udvikler sig til egentlig sygdom. Et screeningsprogram omfatter således mange mennesker som føler sig raske med henblik på at finde få syge.
Der foreligger i dag [ NB: Bogen er fra 2001 – tallet er højere i dag ] over 35 screeningsmuligheder fordelt på prænatal screening (screening af ufødte børn), screening for hjerte-kar-sygdomme, for kræft, stofskifte-, infektionssygdomme og for psykiske lidelser. Det er åbenbart at det hverken etisk eller økonomisk vil være relevant at indføre et stort antal screeningsprogrammer.
De mange screeningsmuligheder rejser en række problemer af bl.a. etisk, social og juridisk karakter, hvorfor ikke bare Sundhedsstyrelsen, men også WHO og Europarådet, har udarbejdet retningslinjer for de forudsætninger der bør være opfyldt inden screeningsprogrammer iværksættes. Meget tyder imidlertid på at de fleste screeningsprogrammer iværksættes på et mangelfuldt grundlag og med en del tilfældighed i beslutningsprocessen.


Det er politisk tungt arbejde at sikre midler til sygdomsforebyggelse da behandlingsopgaven naturligt presser sig på med stor kraft. Forebyggelse nyder ganske vist meget politisk velvilje, men der opstår som beskrevet nemt problemer når pengene skal prioriteres. Dagens politik er stærkt præget af ønsket om hurtige og synlige resultater, og herved bringes den langsigtede forebyggelse i en vanskelig situation.”

iv. “Omkostnings-effekt analyse har til formål a sætte omkostninger ved en intervention i forhold til sundhedseffekten. Omkostninger omfatter ressourceforbrug ved interventionen. Herfra trækkes eventuelle besparelser, hvis interventionen erstatter en eksisterende indsats, eller besparelser der kan tilskrives interventionens sundhedseffekt, fx færre sygehusindlæggelser [ bemærk at sådanne størrelser til tider vil være relativt lette at manipulere med, med henblik på at forme analysen så man når det ønskede resultat, bl.a. fordi mange af de interventioner der måles på kun vanskeligt kan evalueres i forhold til status quo – US ]. Interventionsomkostninger minus eventuelle besparelser betegnes som interventionens nettoomkostning og kan være et negativt beløb (besparelser er større end interventionsomkostninger).
Sundhedseffekten måles i forhold til interventionens “end point”. I stigende grad anvendes enten “vundne leveår” eller forbedret sundhedsrelateret livskvalitet som sundhedseffektmål i omkostnings-effekt analyser. […] Vundne leveår og sundhedsrelateret livskvalitet kan forenes i begrebet og måleinstrumentet “kvalitetsjusterede vundne leveår“.
Hvis nettoomkostningerne er negligable eller negative og (underforstået) sundhedseffekten er positiv, siges interventionen at være absolut omkostningseffektiv. Mere sundhed for ingen penge eller besparelser. Hyppigst er nettoomkostningerne positive,”

[Jeg har tidligere skrevet om dette her og fandt det værd at genposte denne figur her, fordi det er en super vigtigt pointe at have i baghovedet at langt de fleste nye behandlingstiltag som kommer til over tid ikke giver ‘mere sundhed for færre penge’. Nej, de fleste giver mere sundhed – men koster også mere:]

“og man beregner en ratio af nettoomkostninger og sundhedseffekter, fx nettoomkostning pr. vundet (eventuelt kvalitetsjusteret) leveår. Det vurderes herefter politisk eller fagligt om denne “pris” er for høj, eventuelt ved at sammenligne med andre interventioners ratioer. […] Prædikatet omkostningseffektiv forudsætter altså ikke at man sparer penge ved interventionen.”


I forbindelse med forebyggelse skelnes mellem tre former for forebyggelse; primær, sekundær og tertiær. I det pågældende studie er de tre grupper af forebyggende tiltag defineret således:

Primær: “designed to completely avert the occurence of disease or injury.”
Sekundær: “slow, halt, or reverse the progression of disease or injury through detection and intervention.”
Tertiær: “treatments designed to limit disability after harm has occured, and to promote the highest attainable level of functioning among individuals with irreversible or chronic disease.”

For nogle sygdomme er det lettere at eksemplificere de forskellige forebyggelsestyper end andre. I forbindelse med hjerte-kar-sygdom kunne man sige, at en informationskampagne om vægttab og rygestop på populationsplan gennemført med henblik på at forebygge hjerte-kar-sygdom ville blive betragtet som primær forebyggelse, hvorimod blodtryksbehandling af en hypertensiv type 2 diabetiker ville kunne betragtes som sekundær forebyggelse. Endelig ville blodfortyndende medicin til en person som havde haft et myokardieinfarkt være at anskue som en form for tertiær forebyggelse.

Men tilbage til kapitel 7:

“En metaundersøgelse af 310 økonomiundersøgte interventioner i det amerikanske sundhedsvæsen, hvor “end point” var overlevelse eller vundne leveår, viste en høj omkostningseffektivitet (lav pris pr. vundet leveår) for primær forebyggelse i forhold til sekundær forebyggelse (inklusive tidlig diagnosticering mv.) og behandlingsindsats i øvrigt (Tengs m.fl. 1995). […] de fleste inkluderede økonomiundersøgelser medtager omkostninger over et forholdsvist langt tidsforløb. Så der kan drages to konklusioner af metaundersøgelsen:
1. At primær forebyggelse, såvel som sekundær og tertiær, koster ressourcer på kort og mellemlangt sigt (ca. 10 år).
2. At primær forebyggelse er omkostningseffektiv hvis den virker.” [den er billigere end de andre for givne sundhedsudfald.]

Det bør måske inkluderes, at medianomkostningen pr. vundet leveår i $, 1993-priser var 5.000 for interventioner udført med henblik på primær forebyggelse, og hhv. 23.000 og 22.000 for interventioner med sigte mod sekundær og tertiær forebyggelse, med ca. 100 studier inkluderet fra hver gruppe.


“Når forebyggelse koster ressourcer i sundhedsvæsenet, det vil sige ikke “tjener sig selv hjem” ved besparelser til diagnostik og behandling, og samtidig er omkostningseffektiv, det vil sige at omkostning i forhold til effekt er relativ lav, så er den tredje konklusion at forebyggelse skal finansieres. Da der ikke vil være råd til det hele, er den fjerde konklusion at der også må prioriteres. […]

Man fornemmer sommetider en forsagt irritation blandt “forebyggerne” over at ikke-farmakologisk forebyggelse har sværere ved at slå igennem end farmakologisk baseret forebyggelse, fx statinterapi i stedet for diæt og motion. Dette kan hænge sammen med forskellige finansieringsmekanismer og -systemer. Er et lægemiddel tildelt generelt medicintilskud, så flyder de offentlige kroner helt automatisk. Det gælder ikke for den ikke-farmakologiske forebyggelse. Her skal der enten særlige, og ofte ad hoc, bevillinger til, eller den enkelte fagperson skal tilkæmpe sig midler i en forvaltning eller afdeling.”

Mere senere, for så vidt syntes jeg næsten bogen først rigtigt begyndte omkring dette punkt.

August 24, 2011 Posted by | Data, Sundhed | Leave a comment

The National Museum of Denmark

(click to view in a higher resolution)

I went there today. “The National Museum is Denmark’s largest museum of cultural history” – and sadly, because of travel arrangements and real life stuff that came up, I had but 4 hours to spend there. Which is far from enough.

Given that I spent 4 hours there I naturally liked it a lot, it wasn’t that I couldn’t find the exit (there are signs in both Danish and English). It’s a great museum. If you don’t live in Denmark but happen one day to be in Copenhagen for some reason or another, consider wasting a full day here (or you can combine it with a visit to Glyptoteket – they are located very close to each other).

I took a lot of pictures along the way (250+), I’ve posted quite a few more of them below the fold (click the link with the Danish text: ‘læs mere’ to see the rest).

Continue reading

August 23, 2011 Posted by | Anthropology, Archaeology, culture, Personal, Random stuff | Leave a comment

Wikipedia articles of interest

1. Seven Bridges of Königsberg.

“The Seven Bridges of Königsberg is a historically notable problem in mathematics. Its negative resolution by Leonhard Euler in 1735 laid the foundations of graph theory and prefigured the idea of topology.

The city of Königsberg in Prussia (now Kaliningrad, Russia) was set on both sides of the Pregel River, and included two large islands which were connected to each other and the mainland by seven bridges.

The problem was to find a walk through the city that would cross each bridge once and only once. The islands could not be reached by any route other than the bridges, and every bridge must have been crossed completely every time; one could not walk halfway onto the bridge and then turn around and later cross the other half from the other side. Euler proved that the problem has no solution. There could be no non-retracing continuous curve that passed through all seven of the bridges. The difficulty was the development of a technique of analysis and of subsequent tests that established this assertion with mathematical rigor.”

2. Necessary and sufficient condition.

Somewhat basic stuff, but I just realized that if an individual has never dealt much with math or logic maybe this kind of distinction is unknown to the individual in question. I think it’s smart to go back to this kind of stuff now and again even if you know about it. Stuff like this makes it easier to evaluate arguments without spending too much time and if you haven’t dealt with it in a while, you forget stuff and make mistakes.

3. Battle of Agincourt.

“The Battle of Agincourt[a] was a major English victory against a numerically superior French army in the Hundred Years’ War. The battle occurred on Friday, 25 October 1415 (Saint Crispin’s Day, November 3 NS), near modern-day Azincourt, in northern France.[6][b] Henry V’s victory crippled France and started a new period in the war, during which Henry married the French king’s daughter and his son, Henry VI, was made heir to the throne of France” […]

“Henry, worried about the enemy launching surprise raids, and wanting his troops to remain focused, ordered all his men to spend the night before the battle in silence, with having an ear cut off the punishment for disobeying.” […]

“The field of battle was arguably the most significant factor in deciding the outcome. The recently ploughed land hemmed in by dense woodland favoured the English, both because of its narrowness, and because of the thick mud through which the French knights had to walk.[26][27] An analysis by Battlefield Detectives has looked at the crowd dynamics of the battlefield.[28] The 1,000–1,500 English men-at-arms are described as shoulder to shoulder and four deep, which implies a tight line about 250–300 men long (perhaps split in two by a central group of archers). The remainder of the field would have been filled with the longbowmen behind their palings. The French first line contained men-at-arms who had no way to outflank the English line. The French, divided into the three battles, one behind the other at their initial starting position, could not bring all their forces to bear: the initial engagement was between the English army and the first battle line of the French. When the second French battle line started their advance, the soldiers were pushed closer together and their effectiveness was reduced. Casualties in the front line from longbow arrows would also have increased the congestion, as the following men would have to walk around the fallen. […] Although the French initially pushed the English back, they became so closely packed that they are described as having trouble using their weapons properly. The French monk of St. Denis says: “Their vanguard, composed of about 5,000 men, found itself at first so tightly packed that those who were in the third rank could scarcely use their swords”,[30] and the Burgundian sources have a similar passage. In practice there was not enough room for all these men to fight, and they were unable to respond effectively when the English longbowmen joined the hand-to-hand fighting. By the time the second French line arrived, for a total of about eight thousand men (depending on the source), the crush would have been even worse. The press of men arriving from behind actually hindered those fighting at the front.

As the battle was fought on a recently ploughed field, and there had recently been heavy rain leaving it very muddy, it proved very tiring to walk through in full plate armour. The French monk of St. Denis describes the French troops as “marching through the middle of the mud where they sank up to their knees. So they were already overcome with fatigue even before they advanced against the enemy”. The deep, soft mud particularly favoured the English force because, once knocked to the ground, the heavily armoured French knights had a hard time getting back up to fight in the mêlée. Barker states that some knights, encumbered by their armour, actually drowned in their helmets.[31] Their limited mobility made them easy targets for the volleys from the English archers. The mud also increased the ability of the much more lightly armoured English archers to join in hand-to-hand fighting against the French men-at-arms. […]

Due to a lack of reliable sources it is impossible to give a precise figure for the French and English casualties. However, it is clear that though the English were outnumbered, their losses were far lower than those of the French. The French sources all give 4,000–10,000 French dead, with up to 1,600 English dead. The lowest ratio in these French sources has the French losing six times more men than the English. The English sources vary between about 1,500 and 11,000 for the French dead, with English dead put at no more than 100.[52]

Barker identifies from the available records “at least” 112 Englishmen who died in the fighting (including Edward of Norwich, 2nd Duke of York, a grandson of Edward III),[53] but this excludes the wounded. One widely used estimate puts the English casualties at 450, not an insignificant number in an army of about 8,500, but far fewer than the thousands the French lost, nearly all of whom were killed or captured. Using the lowest French estimate of their own dead of 4,000 would imply a ratio of nearly 9 to 1 in favour of the English, or over 10 to 1 if the prisoners are included.”

4. Japanese giant hornet.

“The Japanese giant hornet (Vespa mandarinia japonica), is a subspecies of the Asian giant hornet (V. mandarinia). It is a large insect and adults can be more than 4 centimetres (1.6 in) long, with a wingspan greater than 6 centimetres (2.4 in). […]

they can fly 100 kilometres (62 mi) per day and reach up to 40 kilometres per hour (25 mph) […]

In Japan, beekeepers often prefer European honey bees because they are more productive than the endemic Japanese honey bees. However, it is quite difficult to maintain a captive hive of European honey bees, as the hornets will often prey on the bees.

Once a Japanese giant hornet has located a hive of European honey bees it leaves pheromone markers around it, that within a short time attract nest mates that quickly converge on the hive. A single hornet can kill forty European honey bees in a minute and a group of 30 hornets can finish off an entire hive containing 30,000 bees in a little more than three hours. The hornets not only kill the bees, but also dismember them, leaving heads and limbs behind, to finally return to their nest with the bee thoraxes which they feed to their larvae. The hornets also gorge themselves on the bees’ honey.

The Japanese honey bee, on the other hand, has a defense against attacks of this manner. When a hornet approaches the hive to release pheromones, the bee workers emerge from their hive in an angry cloud-formation with some 500 individuals. As they form a tight ball around the hornet, the ball increases in heat [47 °C (117 °F)) from their vibrating wing forming a convection oven, as the heat released by the bees’ bodies is spread over the hornets. Because bees can survive higher temperatures (48 to 50 °C (118 to 122 °F)) than the hornet (44 to 46 °C (111 to 115 °F)), the latter dies.[1] […]

The Japanese giant hornet is large and fearsome, but it is not particularly aggressive unless it feels threatened. It has a venom which is injected from the 6.25 millimetres (0.246 in) stinger and attacks the nervous system and damages tissues of its victims. Compared to other hornet venom, it is not particularly lethal by weight (having an LD50 of 4.1 mg/kg, which compares to the deadliest wasp venom by weight of Vespa luctuosa at 1.6 mg/kg). Instead, the potency of its sting derives from the relatively large amount of venom it is able to inject with each sting.[2] Being stung is extremely painful and requires hospital treatment. On average 40 people die every year of anaphylactic shock after having been stung.[1]”

5. Haile Selassie I. “a defining figure in both Ethiopian and African history” that I’d never heard about.

August 22, 2011 Posted by | Biology, History, Mathematics, Wikipedia, Zoology | Leave a comment


Redigeret af Henri Goldstein.

Bogen har nogle år på bagen, den er fra 2001 og det er faktisk lang tid siden i forhold til mange af de emner, der berøres. Bogen har to dele, en kort ‘generel del’ på 60-70 sider og en ‘specifik del’ på et par hundrede sider plus det løse. Den generelle del fandt jeg generelt var skuffende, der var meget lidt økonomi og tradeoffs inde over, og meget af det, der var, var emner jeg allerede har stiftet bekendtskab med tidligere – kapitel 7 om ‘sundhedsforebyggelse og økonomi’ var et lyspunkt, men som titlen på kapitlet også indikerer, var der ikke meget af den slags i fremstillingen. Det hjælper ikke at rigtigt meget af det data, der indgår i den del af fremstillingen, er stærkt forældet og at bidragyderne stadig taler om amternes rolle i forebyggelsesregi. Der er 24 kapitler og hvert kapitel er skrevet af en eller to bidragydere; der er 28 ‘eksperter’, et ord bogen selv bruger, i alt. De fleste er speciallæger, dertil kommer enkelte politikere (jeg fandt deres bidrag noget tynde, men det kan bare være mig). Den specifikke del er bedre, men kommer ikke meget ind på økonomiske problemstillinger – hvilket for så vidt ikke kan siges at være et stort kritikpunkt, da det ikke er her bidragydernes ekspertise ligger. En meget kort opsummering af mange af kapitlerne i den specifikke del ville bestå i følgende: Nedbring rygning, nedbring alkoholforbruget, håndter fedmeproblemet og forsøg at få folk til at dyrke motion. Der er naturligvis mere end det, men rigtigt mange grupper af sygdomme har disse risikofaktorer til fælles, og det har vi vidst i lang tid.

Jeg vil sandsynligvis citere fra værket senere på ugen. Jeg synes ikke rigtigt jeg kan anbefale den, primært fordi den er 10 år gammel og generelt skøjter meget let hen over de økonomiske aspekter. Men jeg fandt en del af skidtet interessant alligevel.

August 22, 2011 Posted by | Sundhed | Leave a comment

Follow-up on the eye study

A couple of previously published related posts (in Danish) here. I promised an update when the results were in, and now they are. Unfortunately the article is gated, but here’s the abstract:

“Purpose:  Diabetic retinopathy is characterised by morphological lesions secondary to retinal vascular impairment, and it is assumed that changes in the diameter regulation of retinal arterioles are involved in the disease pathogenesis. It has previously been shown that prostaglandin F2α can constrict retinal arterioles in vitro. In the present study, we investigated whether a similar effect could be achieved by topical administration in diabetic patients with dilated retinal arterioles and retinopathy.

Methods: Twenty-two type 1 diabetic patients with mild retinopathy and twenty-four matched normal controls were randomized to topical treatment with the prostaglandin F2α agonist latanoprost twice daily for 1 week, followed by similar treatment with the cyclo-oxygenase inhibitor diclofenac, or to receive the two medications in the reverse order. The Dynamic Vessel Analyzer was used to assess the effect of the interventions on the resting diameter of retinal vessels and on the diameter response of retinal arterioles to increased blood pressure (BP) induced by isometric exercise and flicker stimulation.

Results: Latanoprost reduced the resting diameter of retinal arterioles significantly in patients with diabetes (p = 0.01), but had no effect on normal persons. Diclofenac had no effect on the resting diameter of arterioles in either of the groups. The diameter responses to increased BP and flicker stimulation were not significantly changed by any of the treatments.

Conclusion: Long-term prospective studies are needed to study the effect of topical treatment with latanoprost on the consequences of retinal hyperperfusion in retinal vascular diseases such as diabetic retinopathy.”

So, to Plamus and others who might have no idea what I’m talking about, I participated in this study and wrote a couple of short posts about it back then. Only yesterday I incidentally asked Kathrine to send me the study and kindly enough she did – but I’ll not put it up here.

Diabetic retinopathy is a much feared complication to diabetes. It is ‘the most frequent cause of blindness of adults in the age of 20-74’ in Denmark. So far the usual approach to dealing with this complication has been (still is) to screen diabetics by taking pictures of their eyes at regular intervals (once every year) and then intervene when complications become significant enough to ‘merit attention’, so to speak – usually by means of surgical intervention. One of the main reasons why the screening protocol is implemented, in case you were wondering, is that patients will often have no symptoms even relatively late in the process – you basically don’t get any symptoms before you get bleeds in your eyes significant enough to cause potential vision loss. Katrine’s approach was to figure out if two extant and in other areas widely used pharmacological treatment options could help delay the progression of the damage to the eyes caused by diabetes.

To make a long story short, Latanoprost showed promise in the study, so now Toke Bek, Kathrine’s phd-advisor, has decided to do a long-term study using the drug. Unless I am currently greatly underestimating the long-term risks of complications from participating (have yet to read up on those), I’ll participate in that trial as well.

August 17, 2011 Posted by | Diabetes, Medicine, Ophthalmology, Personal | Leave a comment

Khan Academy stuff

Some videos of interest:

August 17, 2011 Posted by | Biology, Cardiology, Khan Academy, Lectures, Mathematics, Medicine, Physics | 2 Comments

Random stuff/thoughts

Not a lot of time spent developing these ideas, just some things that popped into my mind.

i. Most people like living their own lives less than they’d like living the lives of others. That’s why most of them spend a not insignificant amount of the time they have more or less complete control over (leisure) watching made-up people’s lives and their progress – or they read about them in books. A big part of why TV-soaps and fictional accounts of made-up people’s lives are very popular is that most people have a strong wish that they were living some other person’s life, a life far more interesting than their own. Because face it, most people’s lives aren’t that interesting. And even for people who’ve done very well for themselves, reality can’t compete with fantasy. Everybody implicitly know this and when we consider societal norms we usually find that taking the fictional stuff too seriously is considered immature, bordering on childish – but strangely enough, spending quite a bit of time in fictional worlds is not. That’s interesting, it’s okay to try to escape reality on a regular basis but only if you’re not too serious about it.

ii. People are extremely good at coming up with plausible sounding reasons for not parting voluntarily with their money. When I say money people just think ‘money’. But money is a claim on resources. And in a biological evolutionary framework resources really matter, bigtime. A big part of most people’s moral philosophy is stuff that they make up on the go, or perhaps their grandparents did. Their ideas about what is moral usually turn out to be ideas that make them look good and make it okay for them to not part with their ressources. Perhaps the ideas that make it through even make it okay for them to cheat others – like the guy on the right:

That’s because other people (and organisms, this process has been implicitly going on since the time before sexual reproduction) have tried to coax and cheat them for millions of years. When your date demands that you pay for her dinner, she’s engaging in the latest of a very long series of battles about limited ressources between the sexes.

iii. When people think about major threats to humanity (perhaps not extinction risk, most people don’t give that one much thought – but at least major risks), most people either think in terms of environmental parameters (climate, asteroids) or in terms of intraspecific competition (we’ll all kill each other in a nuclear holocaust). We like to think that humans are really important, and we like to think that we’re important enough for other life-forms not to matter all that much in the big picture; we like to think that humans are by now beyond the point where interspecific competition even matters. The funny thing is that a disease like smallpox alone was responsible for an estimated 300–500 million deaths during the 20th century – a death toll high enough to wipe out the entire human race just a thousand years ago. Roughly a third of the world’s population has been infected with tuberculosis. People who think we don’t still compete with other lifeforms all the time don’t think big enough – or rather ‘small enough’, as it were.

iv. This is a nice one to have at hand in the future.

August 16, 2011 Posted by | dating, rambling nonsense, Random stuff, Religion | 6 Comments

Thief of Time

This one was the hardest of the ones I’ve read this week to get through, and I don’t think it’s because it’s the last of them. First part is not, in my opinion, all that good. It’s not all ‘not-particularly-good’ though, some of it is brilliant, but there’s less of that stuff than there most often are in Discworld novels. I’m somewhat partial to some of the passages involving Igor and some of them, as well as the conversation between Susan Sto Helit and Madam Frout, had me laughing out loud.

Incidentally, I am told that I perhaps shouldn’t be all that worried about spoilers in my posts, but the ‘do unto others…’-thing matters somewhat here and I am very much a ‘dislike spoilers-guy’ myself.

Some stuff from the book:

i. “The shop bell rang. He sighed and put down his eyeglass. He didn’t rush, though. There was a lot to look at in the shop. Sometimes he even had to cough to attract the customer’s attention. That being said, sometimes Jeremy had to cough to attract the attention of his reflection when he was shaving.
Jeremy tried to be an interesting person. The trouble was that he was the kind of person who, having decided to be an interesting person, would first of all try to find a book called How to Be An Interesting Person and then see whether there were any courses available.” (remind me of anyone? Hmm…)

ii. “There was a row of alarm clocks on the table by Jeremy’s bed. He did not need them, because he woke up when he wanted to. They were there for testing. He set them for seven, and woke up at 6.59 to check that they went off on time.”

iii. “He put the book aside and spent the rest of the evening doing a little design work for the Guild [of Clockmakers]. They paid him handsomely for this, provided he promised never to turn up in person.”

iv. “Feeling that Igor was expecting more of him, Jeremy made a show of reading through the rest of what turned out to be references. Some of them were written in what he could only hope was dried brown ink, one was in crayon, and several were singed around the edges. They were all fulsome. After a while, though, a certain tendency could be noted amongst the signatories.
‘This one is signed by someone called Mad Doctor Scoop,’ he said.
‘Oh, he wathn’t actually named mad, thur. It wath more like a nickname, ath it were.’ [Igor has a lisp]
‘Was he mad, then?’
‘Who can thay, thur?’ said Igor calmly.
‘And Crazed Baron Haha? It says under Reason for Leaving that he was crushed by a burning windmill.’
‘Cathe of mithtaken identity, thur.’
‘Yeth, thur. I underthtand the mob mithtook him for Thcreaming Doctor Bertherk, thur.’
‘Oh. Ah, yes.’ Jeremy glanced down. ‘Who you also worked for, I see.’
‘Yeth, I see.’
‘Yeth, thur.’
‘And who died of blood poisoning?’
‘Yeth, thur. Cauthed by a dirty pitchfork.’
‘And … Nipsie the Impaler?’
‘anyway, I’m not insane!’
‘That’th not compulthory, thur.’
‘I’ve actually got a piece of paper that says I’m not, you know.’
‘Well done, thur.’
‘Not many people have one of those!’
‘Very true, thur.’
‘I take medicine, you know!'”

v. “The sound of distant chanting followed them. Lu-Tze, who was not holy and therefore could think unholy thoughts, occasionally wondered whether the chanting monks were chanting anything, or were just going ‘aahaaahahah’. You could never tell with all that echo.”

vi. “‘Things either exist or they don’t,’ said Jeremy. ‘I am very clear about that. I have medicine.’
‘It ecthithted,’ said Igor, ‘and then, after it did, it never had. Thith ith what my grandfather told me, and he built that clock with thethe very handth!’
Jeremy looked down. Igor’s hands were gnarled, and, now he came to look at them, had a lot of scar tissue around the wrists. [Igor also has two thumbs on each hand]
‘We really believe in heirloomth in our family,’ said Igor, catching his gaze.
‘Sort of … hand-me-downs, ahahaha,’ said Jeremy. He wondered where his medicine was.”

vii. “‘But the Guild—‘
‘You don’t exist at the Guild.’
‘That’s stupid, I’m in the Guild records.’
‘No, you’re not. We’ll see to that.’
‘How? You can’t rewrite history!’
‘Bet you a dollar?’
‘What have I joined?’
‘We’re the most secret society that you can imagine.’
‘Really? Who are you, then?’
‘The Monks of History.’
‘Huh? I’ve never heard of you!’
‘See? That’s how good we are.'”

viii. “‘The reason I’ve called you here, Susan, is that, er, the reason is—‘ Madam Frout faltered.
‘There have been complaints?’ said Miss Susan.
‘Er, no … er … although Miss Smith has told me that the children coming up from your class are, er, restless. Their reading ability is, she says, rather unfortunately advanced …’
‘Miss Smith thinks a good book is about a boy and his dog chasing a big red ball,’ said Miss Susan. ‘My children have learned to expect a plot. No wonder they get impatient. We’re reading Grim Fairy Tales at the moment.’
‘That is rather rude of you, Susan.’
‘No, madam. That is rather polite of me. It would have been rude of me to say that there is a circle of Hell reserved for teachers like Miss Smith.’
‘But that’s a dreadf—‘ Madam Frout stopped, and began again. ‘You should not be teaching them to read at all yet!’ she snapped. […] ‘I mean,’ the headmistress mumbled, ‘childhood is a time for play and—‘
‘Learning,’ said Miss Susan.
‘Learning through play,’ said Madam Frout, grateful to find familiar territory. ‘After all, kittens and puppies—‘
‘—grow up to be cats and dogs, which are even less interesting,’ said Miss Susan, ‘whereas children should grow up to be adults.'”
‘What precisely was it you wanted, madam?’ she said. It’s just that I’ve left the class doing algebra, and they get restless when they’ve finished.’
‘Algebra?’ said Madam Frout […] ‘But that’s far too difficult for seven-year-olds!’
‘Yes, but I didn’t tell them that and so far they haven’t found out,’ said Susan.

ix. “‘They’re going to do something to Time? I thought they weren’t allowed to do things like that.’
‘No-one would be that stu—‘
Susan stopped. Of course someone would be that stupid. Some humans would do anything to see if it was possible to do it. If you put a large switch in some cave somewhere, with a sign on it saying ‘End-of-the-World Switch. PLEASE DO NOT TOUCH’, the paint wouldn’t even have time to dry.”

x. “The Code of the Igors was very strict.
Never Contradict: it was no part of an Igor’s job to say things like ‘No thur, that’th an artery.’ The marther was always right.
Never Complain: an Igor would never say ‘But that’th a thouthand mileth away!’
Never Make Personal Remarks: no Igor would dream of saying anything like ‘I thould have thomething done about that laugh, if I wath you.’
And never, ever Ask Questions. Admittedly, Igor knew, that meant never ask BIG questions. ‘Would thur like a cup of tea around now?’ was fine, but ‘What do you need a hundred virginth for?’ or ‘Where do you ecthpect me to find a brain at thith time of night?’ was not. An Igor stood for loyal, dependable, discreet service with a smile, or at least a sort of lopsided grin, or possibly just a curved scar in the right place.*
And, therefore, Igor was getting worried. Things were wrong, and when an Igor thinks that, they are really wrong.
she had something to hide. Of course, he had for worked for masters who occasionally had a great deal to hide, sometimes in deep holes at midnight. But this situation was morally different…”

xi. “There was a sound rather like a cabbage being sliced in half, and then a head rolled into a basket to cheers and cries of ‘Oh, I say, well done!’ from the crowd. The city of Quirm was a nice, peaceful, law-abiding place and the city council kept it that way with a penal policy that combined the maximum of deterrence with the minimum of reoffending.
The late Gripper rubbed his neck.
‘I demand a retrial!’ he said.
‘It couldn’t possibly have been murder because the…’ The soul of Gripper Smartz fumbled in its spectral pockets for a ghostly piece of paper, unfolded it and continued, in a voice of those to whom the written word is an uphill struggle, ‘… because the bal-ance of my mind was d … dess-turbed.’
REALLY, said Death. He found it best to let the recently departed get things off their chest.
‘Yes, ‘cos I really, really wanted to kill him, right? And you can’t tell me that’s a normal frame of mind, right? He was a dwarf, anyway, so I don’t think that should count as manslaughter.’
‘I’m very prone to being dess-turbed,’ said Gripper. ‘Really, it’s me who’s the victim here. All I needed was a bit of understanding, someone to see my point of view for five minutes…’
‘All dwarfs need a damn good kicking, in my opinion. ‘Ere, you’re Death, right?’
‘I’m a big fan! I’ve always wanted to meet you, y’know?'”

xii. “‘He chopped her head off!’
‘Don’t shout! And keep your head down!’ Susan hissed. […]
‘What’s going on?’
Susan drew back into the shadows. ‘I’m not … entirely sure,’ she said, ‘but I think they’ve tried to make themselves human bodies. Pretty good copies, too. And now … they’re acting human.’
‘Do you call that acting human?’
Susan gave Lobsang a sad look. ‘You don’t get out much, do you? My grandfather says that if an intelligent creature takes a human shape, it starts to think human. Form defines function.’
‘That was the action of an intelligent creature?’ said Lobsang, still shocked.
‘Not only doesn’t get out much, also doesn’t read history,’ said Susan glumly.”

xiii. “‘Oh, where are my manners? Do sit down. Pull up a small child.’
Lobsang and Susan exchanged a glance. Lady LeJean noticed it.
‘I said something wrong?’ she said.
‘We don’t use people as furniture,’ said Susan.”

August 14, 2011 Posted by | Books, Terry Pratchett | 4 Comments

The Truth

The book is about William de Worde, an at this point new character in the Discworld universe, and about how he starts up Ankh-Morpork’s first newspaper. I’ve concluded by now that I somehow on average probably like the Discworld novels which take place in Ankh-Morpork a little better than the ones that do not; I certainly like this one somewhat better than the one I’m currently reading (Thief of Time). It’s a funny book, hilarious at times. Some of the best parts I decided against including below because they contained major spoilers.

Anyway, some excerpts:

i. “[Sergeant Colon of the City Watch] ‘Oi! You!’
For a moment there was no sound but the wind and the gurgling of the water. Then a voice said: ‘Yes?’
‘Are you invading the city or what?’
There was another pause. Then:
‘What what?’ said Colon, raising the stakes.
‘What were the other options?’
‘Don’t mess me about … Are you, down there in the boat, invading this city?’
‘Fair enough,’ said Colon, who on a night like this would happily take someone’s word for it.’Get a move on, then, ‘cos we’re going to drop the gate.’
After a while the splash of the oars resumed and disappeared downriver.
‘You reckon that was enough, just askin’ ’em?’ said Nobby.
‘Well, they ought to know,’ said Colon.”

ii. “He made part of his living by renting out the rat’s nest of old sheds and cellars that backed on to the pub. They tended to be occupied very temporarily by the kind of enthusiastic manufacturer who believed that what the world really, really needed today was an inflatable dartboard.”

iii. “There are, it has been said, two types of people in the world. There are those who, when presented with a glass that is exactly half full, say: this glass is half full. And then there are those who say: this glass is half empty.
The world belongs, however, to those who can look at the glass and say: ‘What’s up with this glass? Excuse me? Excuse me? This is my glass? I don’t think so. My glass was full! And it was a bigger glass.”

iv. “‘It’ll end in trouble, my lord,’ said Ridcully. He’d found it a good general comment in practically any debate. Besides, it was so often true.”

v. “That was the major problem with Mr Tulip, he thought, as they made their way to the ground. It wasn’t that he had a drugs habit. He wanted to have a drugs habit. What he had was a stupidity habit, which cut in whenever he found anything being sold in little bags, and this had resulted in Mr Tulip seeking heaven in flour, salt, baking powder and pickled beef sandwiches. In a street where furtive people were selling Clang, Slip, Chop, Rhino, Skunk, Triplin, Floats, Honk, Double Honk, Gongers and Slack, Mr Tulip had an unerring way of finding the man who was retailing curry powder at what worked out as six hundred dollars a pound. It was so — ing emberrassing. […] Mr Tulip was in any case the kind of heavy-set man who is on the verge of bursting out of his clothes and, despite his artistic inclinations, projected the image of a would-be wrestler who had failed the intelligence test. If his body was a temple, it was one of those strange ones where people did odd things to animals in the basement”

vi. “‘We could live like kings on a dollar a day, Arnold.’
‘What, you mean someone’d chop our heads off?’
‘No, I —‘
‘Someone’d climb up inside the privy with a red-hot poker and —‘
‘No! I meant —‘
‘Someone’d drown us in a butt of wine?’
‘No, that’s dying like kings, Arnold.'”

vii. “‘People like to be told what they already know. Remember that. They get uncomfortable when you tell them new things … well, new things aren’t what they expect. They like to know that, say, a dog will bite a man. That is what dogs do. They don’t want to know a man bites a dog, because the world is not supposed to happen like that. In short, what people think they want is news, but what they really crave is olds.”

viii. “Moving his hands carefully, Dibbler opened the special section of his tray, the high-class one that contained sausages whose contents were 1) meat, 2) from a known four-footed creature, 3) probably land-dwelling.
‘Or may I recommend these, gentlemen,’ he said, and because old habits died hard he couldn’t stop himself from adding, ‘Finest pork.’
‘Good, are they?’
‘You’ll never want to eat another, sir.'”

ix. “A man was standing on the flat parapet just outside the fourth-storey window, back against the wall staring downwards with a frozen expression.
Far below, the crowd were trying to be helpful. It was not in the robust Ankh-Morpork nature to dissuade anyone in this position. It was a free city, after all. So was the advice.
‘Much better to try the Thieves’ Guild!’ a man yelled. ‘Six floors, and then you’re on good solid cobbles! Crack your skull first go!’
‘There’s proper flagstones around the palace,’ advised the man next to him.
‘Well, certainly,’ said his immediate neighbour. ‘But the Patrician’ll kill him if he tries to jump from up there, am I right?'”

x. [From an article in the new paper:] “Mr Hogland, (32) who was threatened at knifepoint, told the Times: ‘I shall recognise the man if I should see him again because not many people have a stocking on their head.'”

xi. “But I’m not even sure there is enough news to fill a—‘ William began, and stopped. That wasn’t the way it worked, was it? If it was in the paper, it was news. If it was news, it went in the paper, and if it was in the paper it was news. And it was the truth.
He remembered the breakfast table. ‘They’ wouldn’t let ‘them’ put it in the paper if it wasn’t true, would they?”

xii. “‘Ah. A troll. Very stupid,’ opined Otto.
‘But hard to fool. I’m afraid I shall have to try the truth. […] He’s a policeman. The truth usually confuses them. They don’t often hear it.'”

xiii. “‘One last thing, sir. Would you like me to say that if anyone saw anything suspicious they should tell you, sir?’ said William. [to the leader of the City Watch]
‘In this town? We’d need every man on the Watch just to control the queue. Just you be careful what you write, that’s all.'”

xiv. “‘Hold on, hold on, there must be a law against killing lawyers.’
‘Are you sure?’
‘There’re still some around, aren’t there?'”

xv. [Just in case you were in doubt about whether being a newspaper editor in Ankh-Morpork is a dangerous job:] “‘What are the odds?’
‘I know what goes on in the duty room. They wouldn’t be watchmen if someone wasn’t running a book.’
‘On Mr de Worde?’
‘Well … six’ll get you ten that he’ll be dead by next Monday, sir.’
‘You might just spread the word that I don’t like that sort of thing, will you?’
‘Yes, sir.’
‘Find out who’s running the book, and when you have found out that it is Nobby, take if off him.'”

xvi. “‘Excuse me, gentlemen?’
A figure had stepped out of the alleyway ahead of them, a knife in each hand.
‘Thieves Guild,’ it said. ‘Excuse me? This is an official robbery.’ […]
‘Official robbery?’ said Mr Tulip slowly.
‘Ah, you’re visitors to our fair city?’ said the thief. ‘Then this is your lucky day, sir and … sir. A theft of twenty-five dollars entitles you to immunity from further street theft for a period of a full six months plus, for this week only, the choice of this handsome box of crystal wine glasses or a useful set of barbeque tools which will be the envy of your friends.’
‘You mean … you’re legal?’ said Mr Pin. […]
‘Yes, sir. Lord Vetinari feels that since there’ll always be some crime in the city, it might as well be organized.'”

xvii. “‘The young man is also an idealist. He has yet to find out that what’s in the public interest is not what the public is interested in.'”

xviii. “Fire was always the terror in those parts of the city where wood and thatch predominated. That was why everyone had been so dead set against any form of fire brigade, reasoning – with impeccable Ankh-Morpork logic – that any bunch of men who were paid to put out fires would naturally see to it that there was a plentiful supply of fires to put out.”

xix. “there was a fire among the dark timbers under the bridge. William realized, as his nostrils shut down, that he was visiting the Canting Crew.
The old towpath had been deserted to start with, but Foul Ole Ron and the rest of them were the reason it stayed that way. They had nothing to steal. They had precious little even to keep. Occasionally the Beggars’ Guild considered running them out of town, but without much enthusiasm. Even beggars need someone to look down on…”

August 13, 2011 Posted by | Books, Terry Pratchett | Leave a comment

How people in science see each other

Perhaps somewhat inaccurate (you try to tell me that a math-phd sees a humanities-phd the same way he sees a fellow math-phd?), but funny:

(click to view in full size)

August 13, 2011 Posted by | academia | Leave a comment

Faust Eric

It is not a long novel, in fact it’s the shortest in the Discworld series I’ve read so far, but it was a good read. Finished it earlier today, I’ve also started on and read the first ~100 pages of The Truth so far today. Will blog that one later on. Because of the length of the book, it’s a bit hard to give a lot of quotes without spoilers, but I think I’ve managed. I like the book but it probably shouldn’t be the first Discworld novel you read, unless perhaps you have a very short attention sp — oooh, shiny read ball! — …an and dislike long books, like, a lot (It is not my impression that this description is one that fits (m?)any of my regular readers, but then again I don’t even know how many of them I have so I could be wrong). Some quotes, relatively spoiler-free:

i. “He knew he wasn’t really Archchancellor material. He hadn’t really wanted the job. He was ninety-eight and had achieved this worthwhile age by carefully not being any trouble or threat to anyone. He had hoped to spend his twilight years completing his seven-volume treatise on Some Little Known Aspects of Kuian Rain-making Rituals, which were an ideal subject for academic study in his opinion since the rituals only ever worked in Ku, and that particular continent had slipped into the ocean several thousand years ago.* The trouble was that in recent years the lifespan of Archchancellors seemed to be a bit on the short side, and the natural ambition of all wizards for the job had given way to a curious, self-effacing politeness. He’d come down one morning to find everyone calling him ‘sir’. It had taken him days to find out why.
His head ached. He felt it was several weeks past his bedtime.”

ii. “Demons have existed on the Discworld for at least as long as the gods, who in many ways they closely resemble. The difference is basically the same as that between terrorists and freedom fighters. […] Astfgl, the new King of the Demons, was furious. Not simply because the air-conditioning had broken down again, not because he felt surrounded by idiots and plotters on every side, and not even because no one could pronounce his name properly yet, but also because he had just been given bad news.”

iii. “Interestingly enough, the gods of the Disc have never bothered much about judging the souls of the dead, and so people only go to hell if that’s where they believe, in their deepest heart, that they deserve to go. Which they won’t do if they don’t know about it. This explains why it is so important to shoot missionaries on sight.”

iv. “It was the first chariot Rincewind had ever seen that was pulled by llamas. That wasn’t what was odd about it. What was odd about it was that it was being carried by people, two holding each side of the axle and running after the animals, their sandalled feet flapping on the flagstones.”

v. “Rincewind wasn’t used to people being pleased to see him. It was unnatural, and boded no good. These people were not only cheering, they were throwing flowers and hats. The hats were made out of stone, but the thought was there. […] ‘I can’t settle down,’ said Rincewind. ‘I’m sorry, but this sort of thing has never happened to me before. All the jewels and things. Everything going as expected. It’s not right.'”

vi. “‘Don’t you see?’ hissed Eric […] We know what’s going to happen! We could make a fortune!’
‘How, exactly?’
‘Well…’ The boy hesitated. ‘We could bet on horses, sort of thing.’
‘Great idea,’ said Rincewind.
‘Yes, and —‘
‘All we’ve got to do is escape, then find out if they have horse races here, and then really try hard to remember the names of the horses that won races in Tsort thousands of years ago.’
They went back to looking glumly at the floor. That was the thing about time travel. You were never ready for it. About the only thing he could hope for, Rincewind decided, was finding da Quirm’s Fountain of Youth and managing to stay alive for a few thousand years so he’d be ready to kill his own grandfather, which was the only aspect of time travel that had ever remotely appealed to him. He had always felt that his ancestors had it coming to them.”

vii. “Travelling by magic always had major drawbacks. There was the feeling that your stomach was lagging behind. And your mind filled up with terror because the destination was always a little uncertain. It wasn’t that you could come out anywhere. “Anywhere” represented a very restricted range of choices compared to the kind of places magic could transport you to.”

August 11, 2011 Posted by | Books, Terry Pratchett | Leave a comment

Making Money

I’m right now rereading this, read the first 300 pages yesterday. I didn’t blog it in details the first time I read it, so I’ll give it some quotes this time around:

i. “‘Look, I can explain,’ he said. […] ‘We got a bit carried away,’ said Moist. ‘We were a bit too creative in our thinking. We encouraged mongooses to breed in the posting boxes to keep down the snakes…’
Lord Vetinari said nothing.
‘Er … which, admittedly, we introduced into the posting boxes to reduce the number of toads …’
Lord Vetinari repeated himself.
‘Er … which, it’s true, staff put in the posting boxes to keep down the snails …’
Lord Vetinari remained unvocal.
‘Er … These, I must in fairness point out, got into the boxes of their own accord, in order to eat the glue on the stamps,’ […]”

ii. “Moist stared disconsolately at a letter from a Ms Estressa Partleigh of the Campaign for Equal Heights. The Post Office, apparently, was not employing enough dwarfs. Moist had pointed out, very reasonably, he thought, that one in three of the staff were dwarfs. She had replied that this was not the point. The point was that since dwarfs were on average two-thirds the height of humans, the Post Office, as a responsible authority, should employ one and a half dwarfs for every human employed. The Post Office must reach out to the dwarf community, said Ms Partleigh.
Moist picked up the letter between thumb and forefinger and dropped it on the floor. It’s reach down, Ms Partleigh, reach down.”

iii. “It would be hard to imagine an uglier building that hadn’t won a major architectural award.”

iv. “‘I read somewhere that the coin represents a promise to hand over a dollar’s worth of gold,’ said Moist helpfully.
Mr Bent steepled his hands in front of his face and turned his eyes upwards, as though praying.
‘In theory, yes,’ he said after a few moments. ‘I would prefer to say that it is a tacit understanding that we will honour our promise to exchange it for a dollar’s worth of gold provided we are not, in point of fact, asked to.’
‘So …. it’s not really a promise?’
‘It certainly is, sir, in financial circles. It is, you see, about trust.’
‘You mean, trust us, we’ve got a big expensive building?’
‘You jest, Mr Lipwig, but there may be a grain of truth there.'”

v. “‘You’re a thief, a trickster, a charlie artful and allround bunco artist! Admit it!’
‘I’m not!’ Moist protested weakly.
‘Liar too,’ said Mrs Lavish cheerfully. ‘And probably an impostor! Oh, don’t waste that innocent look on me! I said you are a rogue, sir! I wouldn’t trust you with a bucket of water if my knickers were on fire!’
Then she prodded Moist in the chest, hard. ‘Well, are you going to lie there all day?’ she snapped. ‘Get up, man. I didn’t say I didn’t like you!’ […]
It was like shaking hands with cold parchment. Mrs Lavish laughed. ‘Ah, yes. Just like the forthright and reassuring grasp of my late husband. No honest man has a handshake as honest as that. How in the world has it taken you so long to find the financial sector?'”

vi. “‘Unfortunately, people have rather lost their faith in banks.’
‘Because we lost their money, usually. Mostly not on purpose.’ […]
‘I don’t really understand how banks work.’
‘You’ve never put money in a bank?’
‘Not in, no.’
‘How do you think they work?’
‘Well, you take rich people’s money and lend it to suitable people at interest, and give as little as possible of the interest back.’
‘Yes, and what is a suitable person?’
‘Someone who can prove they don’t need the money?’
‘Oh, you cynic. But you have got the general idea.'”

vii. “It was impressive. And the first impression it gave Moist was: this is Hell on the day they couldn’t find the matches.”

viii. “‘But don’t let that worry you, Mr Lipspick. Just because I’m employing an Igor and working in a cellar doesn’t mean I’m some sort of madman, ha ha ha.’
‘Ha ha,’ agreed Moist.
‘Ha hah hah!,’ said Hubert. ‘Hahahahahaha!! Ahahahahahahhhhh!!!!! —‘
Bent slapped him on the back. Hubert coughed. ‘Sorry about that, it’s the air down here,’ he mumbled.”

ix. “‘The Times seem to think I intend to nationalize the Royal Bank,’ said Vetinari.
‘Nationalize?’ said Moist.
‘Steal,’ Vetinari translated. ‘I don’t know how these rumours get about.'”

x. “The guards stopped him at the building itself. Moist knew them of old. There was probably an entrance exam for them. If they answered the question ‘What is your name?’ and got it wrong, they were hired. There were trolls that could out-think them. But you couldn’t fool them, or talk them round. They had a list of people who could walk right in, and another of people who needed an appointment. If you weren’t on either, you didn’t get in.”

xi. “‘Good heavens, potatoes are worth more than gold!’
‘Surely not!’
‘If you were shipwrecked on a desert island, what would you prefer, a bag of potatoes or a bag of gold?’
‘Yes, but a desert island isn’t Ankh-Morpork!’
‘And that proves gold is only valuable because we agree it is, right? It’s just a dream. But a potato is always worth a potato, anywhere. A knob of butter and a pinch of salt and you’ve got a meal, anywhere. Bury gold in the ground and you’ll be worrying about thieves for ever. Bury a potato in due season you could be looking at a dividend of a thousand percent!’
‘Can I assume for a moment that you don’t intend to put us on the potato standard?'”

xii. “She was easy to confide in because she never bothered to listen. She used the time to think about what to say next.”

xiii. “His bleary eyes strayed back to the editorial. They [that is, editorials – US], on the other hand, could be quite funny, since they were based on the assumption that the world would be a much better place if it was run by journalists.”

xiv. “‘Good people of Ankh-Morpork! Do any of you think this piece of paper could be worth a dollar? Would anyone give me a dollar for it?’ Pucci waved the paper dismissively.
‘Dunno. What is it,’ said someone, and there was a buzz from the crowd.
‘An experimental banknote,’ said Moist, over the growing hubbub. ‘Just to try out the idea.’
‘How many of them are there, then?’ said the enquiring man.
‘About twelve,’ said Moist.
The man turned to Pucci. ‘I’ll give you five dollars for it, how about that?’
‘Five? It says it’s worth one!’ said Pucci, aghast.
‘Yeah, right. Five dollars, miss.’
‘Why? Are you insane?’
I’m as sane as the next man, thank you, young lady!’
‘Seven dollars here!’ said the next man, raising a hand.
‘This is madness!’ wailed Pucci.
‘Mad?’ said the next man. He pointed a finger at Moist. ‘If I’d bought a pocketful of the black penny stamps when that feller brought them out last year, I’d be a rich man!'”

xv. “‘Why are you always in such a hurry, Mr Lipwig?’
‘Because people don’t like change. But make the change happen fast enough and you go from one type of normal to another.'”

xvi. “‘I thought necromancy was banned,’ said Moist.
‘Oh, we don’t do necromancy here,’ said Hicks. ‘What made you think that?’
Moist looked around at the furnishings, shrugged, and said, ‘Well, I suppose it first crossed my mind when I saw the way the paint was flaking off the door and you can still just see a crude skull and the letters NECR …’
‘Ancient history, ancient history,’ said Hicks quickly. ‘We are the Department of Post-Mortem Communications. A force for good, you understand. Necromancy, on the other hand, is a very bad form of magic done by evil wizards.’
‘And since you are not evil wizards, what you are doing can’t be called necromancy?’
‘And, er, what defines an evil wizard?’ said Adora Belle.
‘Well, doing necromancy would definitely be there right on top of the list.’
‘Could you just remind us what you are going to do?’
‘We’re going to talk to the late Professor Flead,’ said Hicks.
‘Who is dead, yes?’
‘Very much so. Extremely dead.'”

August 10, 2011 Posted by | Books, Terry Pratchett | Leave a comment

New feature: Ratings

Just thought I’d let you know so you don’t miss that one. If you like or dislike a post, you no longer need to leave a comment to tell me that (though I do like comments, so don’t hold back on that account..). At the bottom of each post, there now is a “Rate This”-function where you can give a post 1-5 stars, depending on how much you liked it. Please consider using this feature, it takes less work than writing a comment and the feedback is much appreciated. And please consider using the whole scale, rather than just the four or five star option – a one-star evaluation is valuable information for me too.

Incidentally, you can’t see the rating option from the main site (, so you’ll have to click the specific post you want to evaluate in order to do so.

August 8, 2011 Posted by | blogging | Leave a comment

Khan videos of interest

Some of the stuff I’ve been watching today:

(For the record: I think the above video is just plain cool. I’ve had real trouble ‘getting’ how the kidneys actually work, despite reading quite a bit about that subject at one point; one of the main things I remember from reading about it when I did was that the more details were added to the mix the more confused I tended to get (always a risk when you use peer-reviewed research to supplement wikipedia and similar sources). Khan does a brilliant job here, he’s of course simplifying stuff somewhat but you get it.)

In a couple of later videos he makes a few clarifications regarding the terminology (and frankly if you like this one, you should watch them too – this one is the next in the series) but those are not super important.

The last two were some of the videos I felt I had to take a closer look at in order to get a little more out of some of the sections in the Microbiology textbook. I’m pretty sure this stuff was covered in HS-chemistry, but that’s a long time ago and I haven’t used that stuff since then so a lot of it is just gone. Thanks to Khan, brushing up on some of this stuff is a lot easier than it otherwise could have been.

I think I ought to have a go at the calculus section and linear algebra at some point, but so far I haven’t really found the motivation to do so – besides from watching a few random videos along the way. Incidentally, today I crossed the 100-completed-videos mark (75 of them were in the Cosmology and Astronomy section, which I’ve watched in full from start to finish – and which I highly recommend even though technically some of the videos probably do not belong in this category at all).

August 7, 2011 Posted by | Astronomy, Biology, Cardiology, Chemistry, Khan Academy, Lectures, Medicine, Nephrology, Physics | Leave a comment

Human Microbiology

By Simon P. Hardy. This is another one of those books from the Spring Sale at Stakbogladen (one of the university bookstores) that I got to one-fifth the normal price or so.

Some excerpts from the book:

i) “The variation in size of micro-organisms is not unlimited. The efficiency with which the organism can accumulate nutrients and dispose of waste material through the cytoplasmic membrane will restrict expansion. Many key metabolites (e.g. oxygen) pass passively through the cell wall and cell membrane into the cytosol. The surface area to volume ratio (SA/V) is the limiting factor for the extent to which passively diffusing molecules penetrate the cytosol. […] The physical packing of the nucleic acid […] and cytoplasmic components such as polysomes into a bacterial cell will also limit the minimum size achievable.”

ii) “Organisms growing within a fixed volume of culture media with no additional media added to the culture, is called a batch culture and is a closed system. Growing bacteria is a standard procedure in microbiology laboratories, hence the growth curve obtained [described in the previous section] is described in many microbiology texts. It is, however, artificial. Bacteria do not grow in such a closed system in vivo. There will be tremendous variation in the conditions that organisms find themselves in… […] When nutrients become scarce, bacteria not only reduce total metabolic activity but also synthesise proteins specifically designed to help the cell cope with starvation. In addition, bacteria alter cell wall structure so that the organism is more resistant to damaging chemicals. […] The significance of the stationary phase has been largely overlooked in preference to studies of growth rate, but there are implications for the transmission of bacteria to new hosts. Many bacteria are spread via contaminated water supplies, where nutrients are low and the antibacterial agents (chlorine) are employed to reduce bacterial numbers. These conditions are exactly opposite to those used to test the antibacterial activity of chlorine in the laboratory (actively growing bacteria cultured in nutrient-rich media).”

iii) “The bacteria that colonise or infect man are mesophiles; that is, have optimal growth temperatures between 20 and 40°C […]. Thermophiles are those organisms that grow at elevated temperatures (a good example being those found in thermal lakes) and are not known to infect man. Psychrophiles are those that grow at reduced temperatures below 20°C. These labels are not mutually exclusive. Listeria monocytogenes, for example, is a mesophilic organism that can cause infections in man, but can grow at 4°C…

iv) [Aerobes] are organisms that grow in the presense of atmospheric concentrations of oxygen. Strict aerobes will not grow in the absence of oxygen. […] Microaerophiles need reduced concentrations of oxygen (reduced oxygen tension) in order to grow and will not grow in air nor in the complete absense of oxygen. […] Obligate or strict anaerobes will not grow in the presence of very low concentrations of oxygen and many will also be killed. Different genera of anaerobic bacteria show a range of oxygen sensitivity. Anaerobes are unable to utilise oxygen for respiration and therefore will not grow in the presence of oxygen. Certain anaerobes may tolerate exposure to oxygen for a period, so a distinction has to be made between oxygen killing organisms and oxygen just inhibiting their growth.”
Facultative anaerobes are organisms that will grow in air but can also grow in anaerobic conditions. […] Facultative anaerobes will be the best equipped to deal with varying oxygen tensions, whereas the strict aerobes and strict anaerobes can be considered specialists that have adapted to particular gaseous environments.”

v) “Bacteria that live on and infect man grow best at pH 7 (neutral pH) and may be described as neutrophiles. Acidophiles prefer low pH, less than pH 6, whereas alkaliphiles grow at alkaline pH values over 8. Most organisms will tolerate a range of pH values that extend either side of their pH optimum as a bell-shaped curve (although the shape of the plot need not necessarily be symmetrical). The organisms will possess adaptive mechanisms with which to deal with the limits of tolerance, not least because the organisms themselves will force pH changes through their production of acids or bases as metabolic waste products.”

vi) “In contrast to the degree of detail that has been worked out concerning bacterial metabolic pathways, the routine culture of bacteria in laboratories is often little short of mysticism. The use of culture media with defined ingredients is rarely necessary when cheaper, undefined or semi-defined media will suffice. The media used to culture organisms must be considered highly artificial in comparison to the nutritional conditions encountered by organisms when growing in the natural environment, be that in the environment or on man.”

vii) “One difficulty that undermines our confidence in controlling bacteria and viruses is the definition of death in microbes. Death in bacteria and viruses is a retrospective diagnosis. A bacterium is defined as dead when it cannot be grown. If an organism fails to grow when cultured in a broth or on a plate, having previously been successfully cultivated, then we can say it is dead. Or we can say that we failed to grow the organism in the correct conditions. Because it is impossible to prove a negative event (absence of growth) there is always the worry that we have not killed the organism but simply failed to grow it. The reasons for organisms not growing in laboratory culture media are considerable… […]

A large number of compounds including chemical disinfectants and antibiotics have been identified that can be used in controlling the multiplication of bacteria. Although the mode of action will differ between different compounds, it is helpful to distinguish between whether they act by killing bacteria, in which case they are termed bactericidal or only inhibit bacterial proliferation rather than kill the organism, when they are described as bacteriostatic. […] When exposed to a lethal agent not all of the bacteria in the culture die immediately but, instead, a proportion of the total will be killed per unit time. […] In other words, the more organisms there are, the more organisms are killed.”

viii) “Most non-sporing bacteria (i.e. the vegetative form) are killed when heated to 60°C. Yeasts and fungi need temperatures over 80°C. Bacterial endospores, however, are only killed to any significant extent when held at temperatures above 100°C for over 5 minutes. Bacterial endospores, therefore, pose the greatest problems in obtaining sterility. Because water acts as a better conductor of heat than air, the transfer of energy into the microbe is achieved more efficiently when the organisms are heated in moist or wet conditions…”

And so on. Lots of good stuff here. Some of it is quite hard (probably in part because I don’t remember HS chemistry all that well – but also because a lot of background medical knowledge is assumed throughout the book, some of which I have obtained elsewhere – and some of which I have not..)

August 6, 2011 Posted by | Biology, Books, Infectious disease, Medicine, Microbiology | Leave a comment