Econstudentlog

Water Supply in Emergency Situations (II)

Here’s my first post about the book. In this post I’ve added a few more quotes from a couple of the last chapters of the book:

“Due to the high complexity of the [water supply] systems, and the innumerable possible points of contaminant insertion, complete prevention of all possible terror attacks (chemical, biological, or radiological) on modern drinking water supplying systems […] seems to be an impossible goal. For example, in the USA there are about 170,000 water systems, with about 8,100 very large systems that serve 90% of the population who get water from a community water system […] The prevailing approach to the problem of drinking water contamination is based on the implementation of surveillance measures and technologies for “risk reduction” such as improvement of physical security measures of critical assets (high-potential vulnerability to attacks), [and] installation of online contaminant monitoring systems (OCMS) with capabilities to detect and warn in real time on relevant contaminants, as part of standard operating procedures for quality control (QC) and supervisory control and data acquisition (SCADA) systems. […] Despite the impressive technical progress in online water monitoring technologies […] detection with complete certainty of pollutants is expensive, and remains problematic.”

“A key component of early warning systems is the availability of a mathematical model for predicting the transport and fate of the spill or contaminant so that downstream utilities can be warned. […] Simulation tools (i.e. well-calibrated hydraulic and water quality models) can be linked to SCADA real-time databases allowing for continuous, high-speed modeling of the pressure, flow, and water quality conditions throughout the water distribution network. Such models provide the operator with computed system status data within the distribution network. These “virtual sensors” complement the measured data. Anomalies between measured and modeled data are automatically observed, and computed values that exceed predetermined alarm thresholds are automatically flagged by the SCADA system.”

“Any given tap receives water, which arrives though a number of pipes in the supply network, the transport route, and ultimately comes from a source […] in order to achieve maximum supply security in case of pipe failures or unusual demand patterns (e.g. fire flows) water supply networks are generally designed as complicated, looped systems, where each tap typically can receive water from several sources and intermediate storage facilities. This means that the water from any given tap can arrive through several different routes and can be a mixture of water from several sources. The routes and sources for a given tap can vary over time […] A model can show: *Which sources (well-fields, reservoirs, and tanks) contribute to the supply of which parts of the city? *Where does the water come from (percentage distribution) at any specific location in the system (any given tap or pipe)? *How long has the water been traveling in the pipe system, before it reaches a specific location?
One way to reduce the risk – and simplify the response to incidents – is by compartmentalizing the water supply system. If each tap receives water from one and only one reservoir pollution of one reservoir will affect one well-defined and relatively smaller part of the city. Compartmentalizing the water supply system will reduce the spreading of toxic substances. On the flip side, it may increase the concentration of the toxic substance. It is also likely to have a negative impact on the supply of water for fire flow and on the robustness of the water supply network in case of failures of pipes or other elements.”

An important point in the context of that part of the coverage is that if you want online (i.e. continuous, all-the-time) monitoring of drinking water, well, that’s going to be expensive regardless of how precisely you’re going to go about doing it. Another related problem is that it’s actually not really a simple matter to figure out what it even makes sense to test for when you’re analyzing the water (you can’t test for ‘everything’ all the time, and so the leading approach in monitoring systems employed today is according to the authors based on the idea of using ‘surrogate parameters’ which may be particularly informative about any significant changes in the quality of the drinking water taking place.

“After the collapse of the Soviet Union, the countries of the South Caucasus gained their independence. However, they faced problems associated with national and transboundary water management. Transboundary water management remains one of the key issues leading to conflict in the region today. The scarcity of water especially in downstream areas is a major problem […] The fresh surface water resources of the South Caucasus mainly consist of runoff from the KuraAraz River basins. […] Being a water-poor region, water supply over the Azerbaijan Republic territory totals about 100,000 /km2, which amounts to an average of about 1,000 of water per person per year. Accordingly, Azerbaijan Republic occupies one of the lowest рlaces in the world in water availability. Water resources of the Republic are distributed very irregularly over administrative districts.”

Water provision [in Azerbaijan] […] is carried out by means of active hydrotechnical constructions, which are old-fashioned and many water intake facilities and treatment systems cannot operate during high flooding, water turbidity, and extreme pollution. […] Tap water satisfies [the] needs of only 50% of the population, and some areas experience lack of drinking water. Due to the lack of water supply networks and deteriorated conditions of those existing, about half of the water is lost within the distribution system. […] The sewage system of the city of Baku covers only 70% of its territory and only about half of sewage is treated […] Owing to rapid growth of turbidity of Kura (and its inflows) during high water the water treatment facilities are rendered inoperable thus causing failures in the water supply of the population of the city of Baku. Such situations mainly take place in autumn and spring on the average 3–5 times a year for 1–2 days. In the system of centralized water supply of the city of Baku about 300 emergency cases occur annually […] Practically nobody works with the population to promote efficient water use practices.”

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October 31, 2016 Posted by | Books, Engineering, Geography, Microbiology | Leave a comment

Diabetic nephropathies

Bakris et al.‘s text on this topic is the first book I’ve read specifically devoted to the topic of DN. As I pointed out on goodreads, “this is a well-written and interesting work which despite the low page count cover quite a bit of ground. A well-sourced and to-the-point primer on these topics.” Below I have added a few observations from the book.

“Diabetic nephropathy (DN), also known as diabetic kidney disease (DKD), is one of the most important long-term complications of diabetes and the most common cause of endstage renal disease (ESRD) worldwide. DKD […] is defined as structural and functional renal damage manifested as clinically detected albuminuria in the presence of normal or abnormal glomerular filtration rate (GFR). […] Patients with DKD […] account for one-third of patients demanding renal transplantation. […] in the United States, Medicare expenditure on treating ESRD is approximately US $33 billion (as of 2010), which accounts for 8–9 % of the total annual health-care budget […] According to the United States Renal Data System […], the incidence of ESRD requiring RRT [in 2012] was 114,813 patients, with 44 % due to DKD [9]. A registry report from Japan revealed a nearly identical relative incidence, with 44.2 % of the patients with ESRD caused by diabetes”

Be careful not to confuse incidence and prevalence here; the proportion of diabetics diagnosed with ESDR in any given year is almost certainly higher than the proportion of people with ESDR who have diabetes, because diabetics with kidney failure die at a higher rate than do other people with kidney failure. This problem/fact tends to make some questions hard to answer; to give an example, how large a share of the total costs that diabetics contribute to the whole kidney disease component of medical costs seems to me to be far from an easy question to answer, because you in some sense are not really making an apples-to-apples comparison, and a lot might well depend on the chosen discount rate and how to address the excess mortality in the diabetes sample; and even ‘simply’ adding up medical outlays for the diabetes- and non-diabetes samples would require a lot of data (which may not be available) and work. You definitely cannot just combine the estimates provided above, and assume that the 44% incidence translates into 44% of people with ESDR having diabetes; it’s not clear in the text where the ‘one-third of patients’ number above comes from, but if that’s also US data then it should be obvious from the difference between these numbers that there’s a lot of excess mortality here in the diabetes sample (I have included specific data from the publication on these topics below). The book also talks about the fact that the type of dialysis used in a case of kidney failure will to some extent depend on the health status of the patient, and that diabetes is a significant variable in that context; this means that the available/tolerable treatment options for the kidney disease component may not be the same in the case of a diabetic and a case of a patient with, say, lupus nephritis, and it also means that the patient groups most likely are not ‘equally sick’, so basing cost estimates on cost averages might lead to misleading results if severity of disease and (true) treatment costs are related, as they usually are.

“A recent analysis revealed an estimated diabetes prevalence of 12–14 % among adults in the United States […] In the age group ≥65 years, this amounts to more than 20 %”.

It should be emphasized in the context of the above numbers that the prevalence of DKD is highly variable across countries/populations – the authors also include in the book the observation that: “Over a period of 20 years, 32 studies from 16 countries revealed a prevalence ranging from 11 to 83 % of patients with diabetes”. Some more prevalence data:

“DKD affects about 30 % of patients with type 1 diabetes and 25–40 % of the patients with type 2 diabetes. […] The global prevalence of micro- and macroalbuminuria is estimated at 39 % and 10 %, respectively […] (NHANES III) […] reported a prevalence of 35 % (microalbuminuria) and 6 % (macroalbuminuria) in patients with T2DM aged ≥40 years [24]. In another study, this was reported to be 43 % and 12 %, respectively, in a Japanese population [23]. According to the European Diabetes (EURODIAB) Prospective Complications Study Group, in patients with T1DM, the incidence of microalbuminuria was 12.6 % (over 7.3 years) [25]. This prevalence was further estimated at 33 % in an 18-year follow-up study in Denmark […] In the United Kingdom Prospective Diabetes Study (UKPDS), proteinuria [had] a peak incidence after around 15–20 years after diabetes diagnosis.”

I won’t cover the pathophysiology parts in too much detail here, but a few new things I learned does need to be mentioned:

“A natural history of DKD was first described in the 1970s by Danish physicians [32]. It was characterized by a long silent period without overt clinical signs and symptoms of nephropathy and progression through various stages, starting from hyperfiltration, microalbuminuria, macroalbuminuria, and overt renal failure to ESRD. Microalbuminuria (30–300 mg/day of albumin in urine) is a sign of early DKD, whereas macroalbuminuria (>300 mg/day) represents DKD progression. [I knew this stuff. The stuff that follows below was however something I did not know:]
However, this ‘classical’ natural evolution of urinary albumin excretion and change in GFR is not present in many patients with diabetes, especially those with type 2 diabetes [34]. These patients can have reduction or disappearance of proteinuria over time or can develop even overt renal disease in the absence of proteinuria [30, 35]. […] In the Wisconsin Epidemiologic Study of Diabetic Retinopathy (WESDR) of patients with T2DM, 45.2 % of participants developed albuminuria, and 29 % developed renal impairment over a 15-year follow-up period [37]. Of those patients who developed renal impairment, 61 % did not have albuminuria beforehand, and 39 % never developed albuminuria during the study. Of the patients that developed albuminuria, only 24 % subsequently developed renal impairment during the study. A significant degree of discordance between development of albuminuria and renal impairment is apparent [37]. These data, thus, do not support the classical paradigm of albuminuria always preceding renal impairment in the progression of DKD. […] renal hyperfiltration and rapid GFR decline are considered stronger predictors of nephropathy progression in type 1 diabetes than presence of albuminuria [67]. The annual eGFR loss in patients with DKD is >3 mL/min/1.73 m2 or 3.3 % per year.”

As for the last part about renal hyperfiltration, they however also note later in the coverage in a different chapter that “recent long-term prospective surveys cast doubt on the validity of glomerular hyperfiltration being predictive of renal outcome in patients with type 1 diabetes”. Various factors mentioned in the coverage – some of which are very hard to avoid and some of which are actually diabetes-specific – contribute to measurement error, which may be part of the explanation for the sub-optimal performance of the prognostic markers employed.

An important observation I think I have mentioned before here on the blog is that diabetic nephropathy is not just bad because people who develop this complication may ultimately develop kidney failure, but is also bad because diabetics may die before they even do that; diabetics with even moderate stages of nephropathy have high mortality from cardiovascular disease, so if you only consider diabetics who actually develop kidney failure you may miss some of the significant adverse health effects of this complication; it might be argued that doing this would be a bit like analyzing the health outcomes of smokers while only tallying the cancer cases, and ignoring e.g. the smoking-associated excess deaths from cardiovascular disease. Some observations from the book on this topic:

“Comorbid DM and DKD are associated with high cardiovascular morbidity and mortality. The risk of cardiovascular disease is disproportionately higher in patients with DKD than patients with DM who do not have kidney disease [76]. The incident dialysis rate might even be higher after adjusting for patients dying from cardiovascular disease before reaching ESRD stage [19]. The United States Renal Data System (USRDS) data shows that elderly patients with a triad of DM, chronic kidney disease (CKD), and heart failure have a fivefold higher chance of death than progression to CKD and ESRD [36]. The 5-year survival rate for diabetic patients with ESRD is estimated at 20 % […] This is higher than the mortality rate for many solid cancers (including prostate, breast, or renal cell cancer). […] CVD accounts for more than half of deaths of patients undergoing dialysis […] the 5-year survival rate is much lower in diabetic versus nondiabetic patients undergoing hemodialysis […] Adler et al. tested whether HbA1c levels were associated with death in adults with diabetes starting HD or peritoneal dialysis [38]. Of 3157 patients observed for a median time of 2.7 years, 1688 died. [this example provided, I thought, a neat indication of what sort of data you end up with when you look at samples with a 20% 5-year survival rate] […] Despite modern therapies […] most patients continue to show progressive renal damage. This outcome suggests that the key pathogenic mechanisms involved in the induction and progression of DN remain, at least in part, active and unmodified by the presently available therapies.” (my emphasis)

The link between blood glucose (Hba1c) and risk of microvascular complications such as DN is strong and well-documented, but Hba1c does not explain everything:

“Only a subset of individuals living with diabetes […] develop DN, and studies have shown that this is not just due to poor blood glucose control [50–54]. DN appears to cluster in families […] Several consortia have investigated genetic risk factors […] Genetic risk factors for DN appear to differ between patients with type 1 and type 2 diabetes […] The pathogenesis of DN is complex and has not yet been completely elucidated […] [It] is multifactorial, including both genetic and environmental factors […]. Hyperglycemia affects patients carrying candidate genes associated with susceptibility to DN and results in metabolic and hemodynamic alterations. Hyperglycemia alters vasoactive regulators of glomerular arteriolar tone and causes glomerular hyperfiltration. Production of AGEs and oxidative stress interacts with various cytokines such as TGF-β and angiotensin II to cause kidney damage. Additionally, oxidative stress can cause endothelial dysfunction and systemic hypertension. Inflammatory pathways are also activated and interact with the other pathways to cause kidney damage.”

“An early clinical sign of DN is moderately increased urinary albumin excretion, referred to as microalbuminuria […] microalbuminuria has been shown to be closely associated with an increased risk of cardiovascular morbidity and mortality [and] is [thus] not only a biomarker for the early diagnosis of DN but also an important therapeutic target […] Moderately increased urinary albumin excretion that progresses to severely increased albuminuria is referred to as macroalbuminuria […] Severely increased albuminuria is defined as an ACR≥300 mg/g Cr; it leads to a decline in renal function, which is defined in terms of the GFR [8] and generally progresses to ESRD 6–8 years after the onset of overt proteinuria […] patients with type 1 diabetes are markedly younger than type 2 patients. The latter usually develop ESRD in their mid-fifties to mid-sixties. According to a small but carefully conducted study, both type 1 and type 2 patients take an average of 77–81 months from the stage of producing macroproteinuria with near-normal renal function to developing ESRD [17].”

“Patients with diabetes and kidney disease are at increased risk of hypoglycemia due to decreased clearance of some of the medications used to treat diabetes such as insulin, as well as impairment of renal gluconeogenesis from having a lower kidney mass. As the kidney is responsible for about 30–80 % of insulin removal, reduced kidney function is associated with a prolonged insulin half-life and a decrease in insulin requirements as estimated glomerular filtration rate (eGFR) decline […] Metformin [a first-line drug for treating type 2 diabetes, US] should be avoided in patients with an eGFR < 30 mL/min /1.73 m2. It is recommended that metformin is stopped in the presence of situations that are associated with hypoxia or an acute decline in kidney function such as sepsis/shock, hypotension, acute myocardial infarction, and use of radiographic contrast or other nephrotoxic agents […] The ideal medication regimen is based on the specific needs of the patient and physician experience and should be individualized, especially as renal function changes. […] Lower HbA1c levels are associated with higher risks of hypoglycemia so the HbA1c target should be individualized […] Whereas patients with mild renal insufficiency can receive most antihyperglycemic treatments without any concern, patients with CKD stage 3a and, in particular, with CKD stages 3b, 4, and 5 often require treatment adjustments according to the degree of renal insufficiency […] Higher HbA1c targets should be considered for those with shortened life expectancies, a known history of severe hypoglycemia or hypoglycemia unawareness, CKD, and children.”

“In cases where avoidance of development of DKD has failed, the second approach is slowing disease progression. The most important therapeutic issues at this stage are control of hypertension and hyperglycemia. […] Hypertension is present in up to 85 % of patients with DN/ DKD, depending on the duration and stage (e.g., higher in more progressive cases). […] In a recent meta-analysis, the efficacy and safety of blood pressure-lowering agents in adults with diabetes and kidney disease was analyzed […] In total, 157 studies comprising 43,256 participants, mostly with type 2 diabetes and CKD, were included in the network meta-analysis. No drug regimen was found to be more effective than placebo for reducing all-cause mortality. […] DKD is accompanied by abnormalities in lipid metabolism related to decline in kidney function. The association between higher low-density lipoprotein cholesterol (LDL-C) and risk of myocardial infarction is weaker for people with lower baseline eGFR, despite higher absolute risk of myocardial infarction [53]. Thus, increased LDL-C seems to be less useful as a marker of coronary risk among people with CKD than in the general population.”

“An analysis of the USRDS data revealed an RR of 0.27 (95 % CI, 0.24–0.30) 18 months after transplantation in patients with diabetes in comparison to patients on dialysis on a transplant waiting list [76]. The gain in projected years of life with transplantation amounted to 11 years in patients with DKD in comparison to patients without transplantation.”

October 27, 2016 Posted by | Books, Cardiology, Diabetes, Epidemiology, Health Economics, Medicine, Nephrology, Pharmacology | Leave a comment

Quotes

i. “You will never find time for anything. If you want time, you must make it.” (Charles Buxton)

ii. “When we meet a fact which contradicts a prevailing theory, we must accept the fact and abandon the theory, even when the theory is supported by great names and generally accepted.” (Claude Bernard)

iii. “The cheapest sort of pride is national pride; for if a man is proud of his own nation, it argues that he has no qualities of his own of which he can be proud; otherwise he would not have recourse to those which he shares with so many millions of his fellowmen. The man who is endowed with important personal qualities will be only too ready to see clearly in what respects his own nation falls short, since their failings will be constantly before his eyes. But every miserable fool who has nothing at all of which he can be proud adopts, as a last resource, pride in the nation to which he belongs; he is ready and glad to defend all its faults and follies tooth and nail, thus reimbursing himself for his own inferiority.” (Schopenhauer)

iv. “… whoever attributes no merit to himself because he really has none is not modest, but merely honest.” (-ll-)

v. “It is the possession of a great heart or a great head, and not the mere fame of it, which is worth having, and conducive to happiness. Not fame, but that which deserves to be famous, is what a man should hold in esteem.” (-ll-)

vi. “It is not knowledge, but the act of learning, not the possession of but the act of getting there, which grants the greatest enjoyment.” (Gauss)

vii. “People may flatter themselves just as much by thinking that their faults are always present to other people’s minds, as if they believe that the world is always contemplating their individual charms and virtues.” (Elizabeth Gaskell)

viii. “Fools have a habit of believing that everything written by a famous author is admirable.” (Voltaire)

ix. “One always speaks badly when one has nothing to say.” (-ll-)

x. “He who dares not offend cannot be honest.” (Thomas Paine)

xi. “False opinions are like false money, struck first of all by guilty men and thereafter circulated by honest people who perpetuate the crime without knowing what they are doing.” (Joseph de Maistre)

xii. “Learning is not attained by chance, it must be sought for with ardor and attended to with diligence.” (Abigail Adams)

xiii. “It is not easy to be wise for all times, not even for the present much less for the future; and those who judge the past must recollect that, when it was the present the present was future” (Gouverneur Morris)

xiv. “Praise — actual personal praise — oftener frets and embarrasses than it encourages. It is too small when too near.” (Letitia Elizabeth Landon)

xv. “Everybody is seldom to be believed. “They say” is not proof that they know.” (Samuel Laman Blanchard)

xvi. “Useless laws weaken the necessary laws.” (Montesquieu)

xvii. “Not to be loved is a misfortune, but it is an insult to be loved no longer.” (-ll-)

xviii. “Pithy sentences are like sharp nails which force truth upon our memory.” (Denis Diderot)

xix. “One may demand of me that I should seek truth, but not that I should find it.” (-ll-)

xx. “It is bad policy to fear the resentment of an enemy.” (Ethan Allen)

October 24, 2016 Posted by | Quotes/aphorisms | Leave a comment

Water Supply in Emergency Situations (I)

I didn’t think much of this book (here’s my goodreads review), but I did learn some new things from reading it. Some of the coverage in the book overlapped a little bit with stuff I’d read before, e.g. coverage provided in publications such as Rodricks and Fong and Alibek, but I read those books in 2013 and 2014 respectively (so I’ve already forgot a great deal) and most of the stuff in the book was new stuff. Below I’ve added a few observations and data from the first half of the publication.

“Mediterranean basin demands for water are high. Today, the region uses around 300 billion cubic meters per year. Two thirds of Mediterranean countries now use over 500  per year per inhabitant mainly because of heavy use of irrigation. But these per capita demands are irregular and vary across a wide range – from a little over 100 to more than 1,000 per year. Globally, demand has doubled since the beginning of the 20th century and increased by 60% over the last 25 years. […] the Middle East ecosystems […]  populate some 6% of the world population, but have only some 1% of its renewable fresh water. […] Seasonality of both supply and demand due to tourism […] aggravate water resource problems. During the summer months, water shortages become more frequent. Distribution networks left unused during the winter period face overload pressures in the summer. On the other hand, designing the system with excess capability to satisfy tourism-related summer peak demands raises construction and maintenance costs significantly.”

“There are over 30,000 km of mains within London and over 30% of these are over 150 years old, they serve 7.5 million people with 2,500 million liters of water a day.”

“A major flooding of the Seine River would have tremendous consequences and would impact very significantly the daily life of the 10 million people living in the Parisian area. A deep study of the impacts of such a catastrophic natural hazard has recently been initiated by the French authorities. […] The rise of the water level in the Seine during the last two major floods occurred slowly over several weeks which may explain their low number of fatalities: 50 deaths in 1658 and only one death in 1910. The damage and destruction to buildings and infrastructure, and the resulting effect on economic activity were, however, of major proportions […] Dams have been constructed on the rivers upstream from Paris, but their capacity to stock water is only 830 million cubic meters, which would be insufficient when compared to the volume of 4 billion cubic meters of water produced by a big flood. […] The drinkable water supply system in Paris, as well as that of the sewer network, is still constrained by the decisions and orientations taken during the second half of the 19th century during the large public works projects realized under Napoleon III. […] two of the three water plants which treat river water and supply half of Paris with drinkable water existed in 1910. Water treatment technology has radically changed, but the production sites have remained the same. New reservoirs for potable water have been added, but the principles of distribution have not changed […] The average drinking water production in Paris is 615,000 /day.”

They note in the chapter from which the above quotes are taken that a flood comparable to that which took place in 1910 would in 2005 have resulted in 20% of the surface of Paris being flooded, and 600.000 people being without electricity, among other things. The water distribution system currently in place would also be unable to deal with the load, however a plan for how to deal with this problem in an emergency setting does exist. In that context it’s perhaps worth noting that Paris is hardly unique in terms of the structure of the distribution system – elsewhere in the book it is observed that: “The water infrastructure developed in Europe during the 19th century and still applied, is almost completely based on options of centralized systems: huge supply and disposal networks with few, but large waterworks and sewage treatment plants.” Having both centralized and decentralized systems working at the same time/in the same area tends to increase costs, but may also lower risk; it’s observed in the book during the coverage of an Indonesian case-study that in that region the centralized service provider may take a long time to repair broken water pipes, which is … not very nice if you live in a tropical climate and prefer to have drinking water available to you.

“Water resources management challenges differ enormously in Romania, depending on the type of human settlement. The spectrum of settlement types stretches from the very low-density scattered single dwellings found in rural areas, through villages and small towns, to the much more dense and crowded cities. […] Water resources management will always face the challenge of balancing the needs of different water users. This is the case both in large urban or relatively small rural communities. The water needs of the agricultural production, energy and industrial sectors are often in competition. […] Romania’s water resources are relatively poor and unequally distributed in time and space […] There is a vast differential between urban and rural settlements when it comes to centralized drinking water systems; all the 263 municipalities and towns have such systems, while only 17% of rural communities benefit from this service. […] In Braila and Harghita counties, no village has a sewage network, and Giurgiu and Ialomita counties have only one a piece each. Around 47 of the largest cities which do not have wastewater treatment plants (Bucharest, Braila, Craiova, Turnu Severin Tulcea, etc.) produce ∼20 /s of wastewater, which is directly discharged untreated into surface water.”

There is a difference in quality between water from centralized and decentralized supply systems [in the Ukraine (and likely elsewhere as well)]. Water quality in decentralized systems is the worst (some 30% of samples fail to meet standards, compared to 5.7% in the centralized supply). […] The Sanitary epidemiological stations draw random samples from 1,139 municipal, 6,899 departmental, and 8,179 rural pipes, and from 158,254 points of decentralized water supply, including 152,440 wells, 996 springs, and 4,818 artesian wells. […] From the first day following the accident at Chernobyl Nuclear Power Plant (ChNPP), one of the most serious problems was to prevent general contamination of the Dnieper water system and to guarantee safe water consumption for people living in the affected zone. The water protection and development of monitoring programs for the affected water bodies were among the most important post-accident countermeasures taken by the Government Bodies in Ukraine. […] To solve the water quality problem for Kiev, an emergency water intake at the Desna River was constructed within a very short period. […] During 1986 and the early months of 1987, over 130 special filtration dams […] with sorbing screens containing zeolite (klinoptilolite) were installed for detaining radionuclides while letting the water through. […] After the spring flood of 1987, the construction of new dams was terminated and the decision was made to destroy most of the existing dams. It was found that the 90Sr concentration reduction by the dams studied was insignificant […] Although some countermeasures and cleanup activities applied to radionuclides sources on catchments proved to have positive effects, many other actions were evaluated as ineffective and even useless. […] The most effective measures to reduce radioactivity in drinking water are those, which operate at the water treatment and distribution stage.

“Diversification and redundancy are important technical features to make infrastructure systems less vulnerable to natural and social (man-made) hazards. […] risk management does not only encompass strategies to avoid the occurrence of certain events which might lead to damages or catastrophes, but also strategies of adaptation to limit damages.

The loss of potable water supply typically leads to waterborne diseases, such as typhus and cholera.”

Water velocity in a water supply system is about 1 \s. Therefore, time is a primordial factor in contamination spread along the system. In order to minimize the damage caused by contamination of water, it is essential to act with maximum speed to achieve minimum spread of the contaminant”

October 21, 2016 Posted by | Books, Engineering, Geography, Infectious disease, Microbiology | Leave a comment

The Biology of Moral Systems (I)

I have quoted from the book before, but I decided that this book deserves to be blogged in more detail. I’m close to finishing the book at this point (it’s definitely taken longer than it should have), and I’ll probably give it 5 stars on goodreads; I might also add it to my list of favourite books on the site. In this post I’ve added some quotes and ideas from the book, and a few comments. Before going any further I should note that it’s frankly impossible to cover anywhere near all the ideas covered in the book here on the blog, so if you’re even remotely interested in these kinds of things you really should pick up a copy of the book and read all of it.

“I believe that something crucial has been missing from all of the great debates of history, among philosophers, politicians, theologians, and thinkers from other and diverse backgrounds, on the issues of morality, ethics, justice, right and wrong. […] those who have tried to analyze morality have failed to treat the human traits that underlie moral behavior as outcomes of evolution […] for many conflicts of interest, compromises and enforceable contracts represent the only real solutions. Appeals to morality, I will argue, are simply the invoking of such compromises and contracts in particular ways. […] the process of natural selection that has given rise to all forms of life, including humans, operates such that success has always been relative. One consequence is that organisms resulting from the long-term cumulative effects of selection are expected to resist efforts to reveal their interests fully to others, and also efforts to place limits on their striving or to decide for them when their interests are being “fully” satisfied. These are all reasons why we should expect no “terminus” – ever – to debates on moral and ethical issues.” (these comments I also included in the quotes post to which I link at the beginning, but I thought it was worth including them in this post as well even so – US).

“I am convinced that biology can never offer […] easy or direct answers to the questions of what is right and wrong. I explicitly reject the attitude that whatever biology tells us is so is also what ought to be (David Hume’s so-called “naturalistic fallacy”) […] there are within biology no magic solutions to moral problems. […] Knowledge of the human background in organic evolution can [however] provide a deeper self-understanding by an increasing proportion of the world’s population; self-understanding that I believe can contribute to answering the serious questions of social living.”

“If there had been no recent discoveries in biology that provided new ways of looking at the concept of moral systems, then I would be optimistic indeed to believe that I could say much that is new. But there have been such discoveries. […] The central point in these writings [Hamilton, Williams, Trivers, Cavalli-Sforza, Feldman, Dawkins, Wilson, etc. – US] […] is that natural selection has apparently been maximizing the survival by reproduction of genes, as they have been defined by evolutionists, and that, with respect to the activities of individuals, this includes effects on copies of their genes, even copies located in other individuals. In other words, we are evidently evolved not only to aid the genetic materials in our own bodies, by creating and assisting descendants, but also to assist, by nepotism, copies of our genes that reside in collateral (nondescendant) relatives. […] ethics, morality, human conduct, and the human psyche are to be understood only if societies are seen as collections of individuals seeking their own self-interests […] In some respects these ideas run contrary to what people have believed and been taught about morality and human values: I suspect that nearly all humans believe it is a normal part of the functioning of every human individual now and then to assist someone else in the realization of that person’s own interests to the actual net expense of those of the altruist. What [the above-mentioned writings] tells us is that, despite our intuitions, there is not a shred of evidence to support this view of beneficence, and a great deal of convincing theory suggests that any such view will eventually be judged false. This implies that we will have to start all over again to describe and understand ourselves, in terms alien to our intuitions […] It is […] a goal of this book to contribute to this redescription and new understanding, and especially to discuss why our intuitions should have misinformed us.”

“Social behavior evolves as a succession of ploys and counterploys, and for humans these ploys are used, not only among individuals within social groups, but between and among small and large groups of up to hundreds of millions of individuals. The value of an evolutionary approach to human sociality is thus not to determine the limits of our actions so that we can abide by them. Rather, it is to examine our life strategies so that we can change them when we wish, as a result of understanding them. […] my use of the word biology in no way implies that moral systems have some kind of explicit genetic background, are genetically determined, or cannot be altered by adjusting the social environment. […] I mean simply to suggest that if we wish to understand those aspects of our behavior commonly regarded as involving morality or ethics, it will help to reconsider our behavior as a product of evolution by natural selection. The principal reason for this suggestion is that natural selection operates according to general principles which make its effects highly predictive, even with respect to traits and circumstances that have not yet been analyzed […] I am interested […] not in determining what is moral and immoral, in the sense of what people ought to be doing, but in elucidating the natural history of ethics and morality – in discovering how and why humans initiated and developed the ideas we have about right and wrong.”

I should perhaps mention here that sort-of-kind-of related stuff is covered in Aureli et al. (see e.g. this link), and that some parts of that book will probably make you understand Alexander’s ideas a lot better even if perhaps he didn’t read those specific authors – mainly because it gets a lot easier to imagine the sort of mechanisms which might be at play here if you’ve read this sort of literature. Here’s one relevant quote from the coverage of that book, which also deals with the question Alexander discusses above, and in a lot more detail throughout his book, namely ‘where our morality comes from?’

“we make two fundamental assertions regarding the evolution of morality: (1) there are specific types of behavior demonstrated by both human and nonhuman primates that hint at a shared evolutionary background to morality; and (2) there are theoretical and actual connections between morality and conflict resolution in both nonhuman primates and human development. […] the transition from nonmoral or premoral to moral is more gradual than commonly assumed. No magic point appears in either evolutionary history or human development at which morality suddenly comes into existence. In both early childhood and in animals closely related to us, we can recognize behaviors (and, in the case of children, judgments) that are essential building blocks of the morality of the human adult. […] the decision making and emotions underlying moral judgments are generated within the individual rather than being simply imposed by society. They are a product of evolution, an integrated part of the human genetic makeup, that makes the child construct a moral perspective through interactions with other members of its species. […] Much research has shown that children acquire morality through a social-cognitive process; children make connections between acts and consequences. Through a gradual process, children develop concepts of justice, fairness, and equality, and they apply these concepts to concrete everyday situations […] we assert that emotions such as empathy and sympathy provide an experiential basis by which children construct moral judgments. Emotional reactions from others, such as distress or crying, provide experiential information that children use to judge whether an act is right or wrong […] when a child hits another child, a crying response provides emotional information about the nature of the act, and this information enables the child, in part, to determine whether and why the transgression is wrong. Therefore, recognizing signs of distress in another person may be a basic requirement of the moral judgment process. The fact that responses to distress in another have been documented both in infancy and in the nonhuman primate literature provides initial support for the idea that these types of moral-like experiences are common to children and nonhuman primates.”

Alexander’s coverage is quite different from that found in Aureli et al.,, but some of the contributors to the latter work deal with similar questions to the ones in which he’s interested, using approaches not employed in Alexander’s book – so this is another place to look if you’re interested in these topics. Margalit’s The Emergence of Norms is also worth mentioning. Part of the reason why I mention these books here is incidentally that they’re not talked about in Alexander’s coverage (for very natural reasons, I should add, in the case of the former book at least; Natural Conflict Resolution was published more than a decade after Alexander wrote his book…).

“In the hierarchy of explanatory principles governing the traits of living organisms, evolutionary reductionism – the development of principles from the evolutionary process – tends to subsume all other kinds. Proximate-cause reductionism (or reduction by dissection) sometimes advances our understanding of the whole phenomena. […] When evolutionary reduction becomes trivial in the study of life it is for a reason different from incompleteness; rather, it is because the breadth of the generalization distances it too significantly from the particular problem that may be at hand. […] the greatest weakness of reduction by generalization is not that it is likely to be trivial but that errors are probable through unjustified leaps from hypothesis to conclusion […] Critics such as Gould and Lewontin […] do not discuss the facts that (a) all students of human behavior (not just those who take evolution into account) run the risk of leaping unwarrantedly from hypothesis to conclusion and (b) just-so stories were no less prevalent and hypothesis-testing no more prevalent in studies of human behavior before evolutionary biologists began to participate. […] I believe that failure by biologists and others to distinguish proximate- or partial-cause and evolutionary- or ultimate-cause reductionism […] is in some part responsible for the current chasm between the social and the biological sciences and the resistance to so-called biological approaches to understanding humans. […] Both approaches are essential to progress in biology and the social sciences, and it would be helpful if their relationship, and that of their respective practitioners, were not seen as adversarial.”

(Relatedly, love is motivationally prior to sugar. This one also seems relevant, though in a different way).

“Humans are not accustomed to dealing with their own strategies of life as if they had been tuned by natural selection. […] People are not generally aware of what their lifetimes have been evolved to accomplish, and, even if they are roughly aware of this, they do not easily accept that their everyday activities are in any sense means to that end. […] The theory of lifetimes most widely accepted among biologists is that individuals have evolved to maximize the likelihood of survival of not themselves, but their genes, and that they do this by reproducing and tending in various ways offspring and other carriers of their own genes […] In this theory, survival of the individual – and its growth, development, and learning – are proximate mechanisms of reproductive success, which is a proximate mechanism of genic survival. Only the genes have evolved to survive. […] To say that we are evolved to serve the interests of our genes in no way suggests that we are obliged to serve them. […] Evolution is surely most deterministic for those still unaware of it. If this argument is correct, it may be the first to carry us from is to ought, i.e., if we desire to be the conscious masters of our own fates, and if conscious effort in that direction is the most likely vehicle of survival and happiness, then we ought to study evolution.”

“People are sometimes comfortable with the notion that certain activities can be labeled as “purely cultural” because they also believe that there are behaviors that can be labeled “purely genetic.” Neither is true: the environment contributes to the expression of all behaviors, and culture is best described as part of the environment.”

“Happiness and its anticipation are […] proximate mechanisms that lead us to perform and repeat acts that in the environments of history, at least, would have led to greater reproductive success.”

“The remarkable difference between the patterns of senescence in semelparous (one-time breeding) and iteroparous (repeat-breeding) organisms is probably one of the best simple demonstrations of the central significance of reproduction in the individual’s lifetime. How, otherwise, could we explain the fact that those who reproduce but once, like salmon and soybeans, tend to die suddenly right afterward, while those like ourselves who have residual reproductive possibilities after the initial reproductive act decline or senesce gradually? […] once an organism has completed all possibilities of reproducing (through both offspring production and assistance, and helping other relatives), then selection can no longer affect its survival: any physiological or other breakdown that destroys it may persist and even spread if it is genetically linked to a trait that is expressed earlier and is reproductively beneficial. […] selection continually works against senescence, but is just never able to defeat it entirely. […] senescence leads to a generalized deterioration rather than one owing to a single effect or a few effects […] In the course of working against senescence, selection will tend to remove, one by one, the most frequent sources of mortality as a result of senescence. Whenever a single cause of mortality, such as a particular malfunction of any vital organ, becomes the predominant cause of mortality, then selection will more effectively reduce the significance of that particular defect (meaning those who lack it will outreproduce) until some other achieves greater relative significance. […] the result will be that all organs and systems will tend to deteriorate together. […] The point is that as we age, and as senescence proceeds, large numbers of potential sources of mortality tend to lurk ever more malevolently just “below the surface,” so that, unfortunately, the odds are very high against any dramatic lengthening of the maximum human lifetime through technology. […] natural selection maximizes the likelihood of genetic survival, which is incompatible with eliminating senescence. […] Senescence, and the finiteness of lifetimes, have evolved as incidental effects […] Organisms compete for genetic survival and the winners (in evolutionary terms) are those who sacrifice their phenotypes (selves) earlier when this results in greater reproduction.”

“altruism appears to diminish with decreasing degree of relatedness in sexual species whenever it is studied – in humans as well as nonhuman species”

October 5, 2016 Posted by | Anthropology, Biology, Books, Evolutionary biology, Genetics, Philosophy | Leave a comment