Econstudentlog

Quotes

i. “The curse which lies upon marriage is that too often the individuals are joined in their weakness rather than in their strength, each asking from the other instead of finding pleasure in giving.” (Simone de Beauvoir)

ii. “Revolt against a tyrant is legitimate; it can succeed. Revolt against human nature is doomed to failure.” (André Maurois)

iii. “It is easy to be admired when one remains inaccessible.” (-ll-)

iv. “The life of a couple is lived on the mental level of the more mediocre of the two beings who compose it.” (-ll-)

v. “Marriage is not something that can be accomplished all at once; it has to be constantly reaccomplished. A couple must never indulge in idle tranquility with the remark: “The game is won; let’s relax.” The game is never won. […] A successful marriage is an edifice that must be rebuilt every day.” (-ll-)

vi. “Almost all men improve on acquaintance.” (-ll-)

vii. “There is no absurdity or contradiction to which passion may not lead a man. When love or hate takes control, reason must submit and then discover justifications for their folly.” (-ll-)

viii. “When I hear somebody sigh that “Life is hard,” I am always tempted to ask, “Compared to what?”” (Sydney J. Harris)

ix. “The most worthwhile form of education is the kind that puts the educator inside you, as it were, so that the appetite for learning persists long after the external pressure for grades and degrees has vanished. Otherwise you are not educated; you are merely trained.” (-ll-)

x. “As we grow older, we should learn that these are two quite different things. Character is something you forge for yourself; temperament is something you are born with and can only slightly modify. Some people have easy temperaments and weak characters; others have difficult temperaments and strong characters. We are all prone to confuse the two in assessing people we associate with. Those with easy temperaments and weak characters are more likable than admirable; those with difficult temperaments and strong characters are more admirable than likable.” (-ll-)

xi. “There seems to be a kind of order in the universe, in the movement of the stars and the turning of the earth and the changing of the seasons, and even in the cycle of human life. But human life itself is almost pure chaos. Everyone takes his stance, asserts his own rights and feelings, mistaking the motives of others, and his own.” (Katherine Anne Porter)

xii. “The historian’s one task is to tell the thing as it happened.” (Lucian of Samosata)

xiii. “Innocence most often is a good fortune and not a virtue.” (Anatole France) (L’innocence, le plus souvent, est un bonheur et non pas une vertu.)

xiv. “It is almost impossible systematically to constitute a natural moral law. Nature has no principles. She furnishes us with no reason to believe that human life is to be respected. Nature, in her indifference, makes no distinction between good and evil.” (-ll-) (Il est à peu près impossible de constituer systématiquement une morale naturelle. La nature n’a pas de principes. Elle ne nous fournit aucune raison de croire que la vie humaine est respectable. La nature, indifférente, ne fait nulle distinction du bien et du mal.)

xv. “When a thing has been said and well said, have no scruple: take it and copy it.” (-ll-) (Quand une chose a été dite et bien dite, n’ayez aucun scrupule, prenez-la, copiez.)

xvi. “The whole art of teaching is only the art of awakening the natural curiosity of young minds for the purpose of satisfying it afterwards.” (-ll-) (L’art d’enseigner n’est que l’art d’éveiller la curiosité des jeunes âmes pour la satisfaire ensuite.) (Two related links)

xvii. “All changes, even the most longed for, have their melancholy; for what we leave behind us is a part of ourselves; we must die to one life before we can enter another.” (-ll-) (Tous les changements, même les plus souhaités ont leur mélancolie, car ce que nous quittons, c’est une partie de nous-mêmes; il faut mourir à une vie pour entrer dans une autre.)

xviii. “We need some imaginative stimulus, some not impossible ideal such as may shape vague hope, and transform it into effective desire, to carry us year after year, without disgust, through the routine-work which is so large a part of life.” (Walter Pater)

xix. “When we lose one we love, our bitterest tears are called forth by the memory of hours when we loved not enough.” (Maurice Maeterlinck) (Quand nous perdons un être aimé, ce qui nous fait pleurer les larmes qui ne soulagent point, c’est le souvenir des moments où nous ne l’avons pas assez aimé.)

xx. “All our knowledge merely helps us to die a more painful death than the animals that know nothing.” (-ll-)

June 30, 2015 Posted by | Quotes/aphorisms | Leave a comment

Promoting the unknown, a continuing series

June 26, 2015 Posted by | Music | Leave a comment

Chronic depression (II)

This will be my last post about the book. Below I have added some more observations from some of the remaining chapters of the book – I noticed after I’d published this post that a few similar observations were also included in the first post, but in the end I decided against removing those arguably superfluous observations from this post (‘if the authors are allowed to repeat themselves, so am I…’).

“General avoidance often weaves its way through the fabric of depressed persons’ lives. One of my (Pettit’s) first clinical supervisors proposed that avoidance captures the true essence of depression. He argued that depression, at its root, is simply the opposite of participation. Although this is surely an overly broad and simplistic conceptualization of depression, it highlights the idea that depressed people are often passive recipients of life, rather than active participants in life. […] depressed persons often have less developed social networks […] depressed persons often exhibit generalized problems with social avoidance. What’s more, evidence suggests that depression is frequently preceded by anxiety of some form […]. Anxiety, of course, is characterized by avoidance of some feared object, cognition, or event. Although anxiety and general social avoidance certainly play a role in depression, a more specific form of social avoidance appears more pertinent to the propagation of depression: Avoidance of interpersonal conflict. We argue that depression is characterized, and even propagated, by a pattern of interpersonal conflict avoidance.”

“It is well-known that depression is associated with a number of factors related to interpersonal avoidance. Four such factors (i.e., low assertiveness, social withdrawal, general avoidance, and shyness) have specifically been identified as interpersonal characteristics of a large number of depressed individuals. […] Two characteristics of assertive behaviors may be of great difficulty to depressed persons. First, asserting oneself requires active engagement with others, which forces the depressed person to overcome feelings of general social anxiety, in addition to overcoming the lethargy and indifference that retard activity in general among such individuals. Second, and more important, assertive behaviors entail making explicit requests of others. Social conventions dictate that requests naturally merit a response, be it positive or negative, and it is at this point that the interpersonal stage for potential disharmony is set. To reach this point, one must conquer general social anxiety and place himself or herself in a position that allows for the possibility of negative, rejecting responses from others. This latter possibility appears to be the sticking point for many depressed persons. That is, depressed persons overcome social inhibition and inertia but are often unwilling to knowingly make themselves vulnerable to interpersonal rejection (although they often engage in behaviors that unknowingly place themselves at greater risk of rejection, such as excessive reassurance-seeking). […] assertiveness is often quite difficult for depressed people. Assertiveness is a necessary component of successful conflict negotiation. […] Avoiding assertive behaviors […] allows the individual to escape the discomfort of receiving negative reactions from others. It also, however, lessens the individual’s chances of obtaining desired outcomes”.

“Price, Sloman, Gardner, Gilbert, and Rohde (1994) argued that depression-related states and behaviors represent evolved forms of a primordial “involuntary subordinate strategy.” Price et al. contended that the involuntary subordinate strategy arose primarily as a means to cope with social competition and conflict, particularly losses therein. Out of this framework, the primary function of depression is to resolve interpersonal conflicts by presenting a “no threat” signal to others. Recent animal research has provided a degree of support for this proposition. In work with cynomolgus monkeys, Shively, Laber-Laird, and Anton (1997) manipulated the social status of a group of females, such that previously dominant monkeys became subordinate to formerly subordinate monkeys. This reduction in social status produced behavioral and hormonal reactions corresponding to depressive reactions among humans. Behaviorally, these monkeys exhibited fearful scanning of the environment, and more important, decreased social affiliation. These behavioral changes suggest that the newly subordinate monkeys were engaging in interpersonal avoidance. Similarly, the monkeys’ hormonal activity transformed, and they began hypersecreting cortisol. Research has demonstrated that hypersecretion of cortisol occurs more frequently among depressed humans […]. Other studies of animal social hierarchies and avoidance provide results consistent with those of Shively et al.”

“It is interesting to note that [a] pattern of being overly reserved or acquiescing with strangers, but extremely negative and antagonistic toward close relatives or romantic partners, is quite common among people who are depressed.”

“[R]esearch on a phenomenon called self-handicapping indicates that depressed people may gain self-protective and other rewards for depressive cognition and behavior. These rewards serve to maintain depressive cognition and behavior, and thereby perpetuate depression. Self-handicapping, a concept with origins in the field of social psychology, refers to placing obstacles in the way of one’s performance on tasks so as to furnish oneself with an external attribution when future outcomes are uncertain […]. That is, in the anticipation of a possible failure or a poor performance of some sort, people may either claim to have some limitation or actuallyproduce a limitation that provides an explanation in the event that they perform poorly. Self-handicapping is a frequently occurring phenomenon and is not limited to depressed people. […] A series of studies by Baumgardner (1991) found self-handicapping, in general, appears to occur in one of two situations. First, it may occur when people have experienced a failure privately and hold concerns about that failure becoming public. […] People may also self-handicap when they have experienced a success publicly yet doubt their ability to maintain that success.”

“[T]wo forms of self-handicapping exist: claimed and acquired (these have also been referred to as self-reported and behavioral, respectively). Claimed handicaps are likely more common than acquired handicaps. […] claimed handicaps occur when people believe that the handicap will explain their poor performance. Acquired handicaps, however, occur when people (a) believe the handicap will explain their poor performance and (b) believe that the handicap will lower others’ future expectations. Both forms of self-handicapping are likely relevant to depression […] evidence suggests that self-handicapping, at least behavioral self-handicapping, occurs more frequently among men than women […]. Self-reported, or claimed, handicaps occur at similar rates among men and women. […] empirical evidence confirms that depressed people are more likely to self-handicap than others.”

“[S]elf-handicapping operates on both intrapsychic and interpersonal levels. That is, the handicap provides the individual a cognitive explanation of the failed performance and also provides an explanation to others who may be privy to the failure. […] In addition to providing an external attribution for failure, barriers to performance increase the likelihood of internal credit for success (i.e., self-enhancement). Consequently, individuals who self-handicap apparently benefit regardless of whether they succeed or fail. […] people self-handicap in the social arena with the goal of promoting a more positive image. Ironically, self-handicapping tends to have the reverse effect [“the perception that people [are] making excuses for their performance” can be damaging, regardless of actual performance] […] lower social expectations presage lower social opportunities, which by itself is a bad prognostic sign for depression. […] Although further empirical research on the interpersonal sequelae of these behaviors is needed before firm conclusions are drawn, they likely reduce opportunities for positive social engagement, increase antagonistic behaviors from others, and reconfirm depressed persons’ views that they are socially inept. The end result, tragically, is continued and exacerbated depression. […] When taken to an extreme, chronic behavioral self-handicapping may significantly hinder interpersonal relations and lead to the development of maladaptive behaviors such as alcoholism and substance dependence.”

“Sacco [argued in a publication] that depressed people’s relationship partners develop mental representations of them that become relatively autonomous and that bias subsequent perceptions of their depressed partners. […] students [in the study] were more likely to attribute the depressed person’s failures to internal, controllable causes, whereas the nondepressed person’s failures were judged to result more from external, uncontrollable factors. Students also considered the causes for failures to be more stable and have a wider impact on the depressed person’s life, as compared with the nondepressed person. The reverse pattern was seen for successful events. That is, successes were judged to result from external, uncontrollable factors among the depressed person but internal, controllable factors for the nondepressed person. Both of these processes are important — depressed persons not only are blamed more for negative events but also are given less credit when positive events occur […] [That] [f]ailures [are] attributed to enduring traits of depressed persons [by others] [and are] viewed as under the control of depressed persons (i.e., the depressed person could have avoided the failure if they had really tried) […] is strikingly similar to depressed persons’ characteristic self-blaming attitude. They attribute their own failures to internal, stable, and global factors […] [In short,] most depressed persons’, attributions are clearly saturated with self-directed blame [and] others tend to adopt the same negative, blaming attributions and behaviors toward depressed persons. […] Once formed, the mental representations [of others] remain stable, regardless of whether the depression has remitted. […] representations of negative behaviors, once solidified, are more difficult to alter than representations of positive behaviors”.

“Others not only fail to recognize positive attributes but also alter their interaction styles with the depressed person. There is evidence that others’ negative views subserve the communications they emit to the negatively represented person. For example, the literature on attributions and relationship functioning has documented a connection between negative attributions and blaming communications […] In short, negative attributions lead to blaming communications and decreased relationship satisfaction. […] Blaming communications, in turn, represent a specific instance of the array of interpersonal indicators shown to predict depression chronicity. […] blame maintenance essentially assures that others will continue to hold negative views of depressed persons, regardless of the depressed persons’ presentations. […] In the context of specifically targeting blame maintenance (or any of the other processes), simultaneous attention to the other processes is warranted, lest resolution of one exacerbate another […]. As an example, blame may serve as a source of selfverification for depressed people. If blame is reduced, negative self-verification strivings may be thwarted, which, in turn, may lead to attempts to restore blame or to meet self-verification needs in other ways (e.g., by reducing performance in a previously adaptive domain) or in other relationships (e.g., with friends).”

“The tendency to avoid potentially uncomfortable social interactions is a stable trait, with shyness demonstrating remarkable consistency from early childhood until late adulthood. […] Shyness has been implicated as a risk factor for depression. […] Social skills represent another potential stable vulnerability to depression. […] people who display poor social skills are less likely to obtain positive outcomes and avoid negative outcomes in interpersonal relationships. As a result, they are more likely to become and stay depressed […] an impressive amount of evidence suggests that people who are depressed also display poor social skills. […] When maladaptive interpersonal behaviors compromise relationships, shy people are more likely to experience loneliness [and] less likely to have good social support […], and are therefore more likely to become even more depressed.”

June 25, 2015 Posted by | Books, Psychology | Leave a comment

Quotes

i. “Habit is habit and not to be flung out of the window by any man, but coaxed downstairs a step at a time.” (Mark Twain)

ii. “We can do without any article of luxury we have never had; but when once obtained, it is not in human natur’ to surrender it voluntarily.” (Thomas Chandler Haliburton)

iii. “An aphorism can contain only as much wisdom as overstatement will permit.” (Clifton Fadiman)

iv. “When you re-read a classic you do not see in the book more than you did before. You see more in you than there was before.” (-ll-)

v. “Statistician: A man who believes figures don’t lie, but admits that under analysis some of them won’t stand up either.” (Esar’s Comic Dictionary, by Evan Esar)

vi. “Many a man who falls in love with a dimple make the mistake of marrying the whole girl.” (-ll-)

vii. “The wise man will live as long as he ought, not as long as he can.” (Seneca the Younger)

viii. “No one is bound to be clever, but every one is under an obligation to be good.” (Jean-Louis Guez de Balzac) (Il n’y a personne qui soit tenu d’être habile; mais il n’y en a point qui ne soit obligé d’être bon.)

ix. “Solitude is certainly a fine thing; but there is pleasure in having someone who can answer, from time to time, that it is a fine thing.” (-ll-) (La solitude est certainement une belle chose, mais il y a plaisir d’avoir quelqu’un qui sache répondre, à qui on puisse dire de temps en temps, que c’est un belle chose.)

x. “Zealous men are ever displaying to you the strength of their belief, while judicious men are shewing you the grounds of it.” (William Shenstone)

xi. “A man has generally the good or ill qualities which he attributes to mankind.” (-ll-)

xii. “Any knowledge that doesn’t lead to new questions quickly dies out: it fails to maintain the temperature required for sustaining life.” (Wisława Szymborska)

xiii. “We are not indeed obliged always to speak what we think, but we must always think what we speak.” (Anne-Thérèse de Marguenat de Courcelles, marquise de Lambert)

xiv. “The most necessary disposition to relish pleasures is to know how to be without them.” (-ll-)

xv. “The pleasures of the world are deceitful; they promise more than they give. They trouble us in seeking them, they do not satisfy us when possessing them and they make us despair in losing them.” (-ll-)

xvi. “Would you be esteemed? live with persons that are estimable.” (-ll-)

xvii. “Nothing is more dangerous than an idea, when it’s the only one we have.” (Émile Chartier)

xviii. “Politeness is for people toward whom we feel indifferent, and moods, both good and bad, are for those we love.” (-ll-)

xix. “Happiness is a reward that comes to those that have not looked for it.” (-ll-)

xx. “It is very true that we ought to think of the happiness of others; but it is not often enough said that the best thing we can do for those who love us is to be happy ourselves.” (-ll-)

June 21, 2015 Posted by | Quotes/aphorisms | Leave a comment

Chronic depression (I)

“This book develops a new explanatory framework for chronic depression […]. The framework rests on the premise that depression appears to include self-sustaining processes, that these processes may be, at least in part, interpersonal, and that understanding of these processes from an interpersonal standpoint may be useful in applied settings.”

I read this book a couple of days ago – here’s my short goodreads review. As mentioned in the review, the book includes quite a bit of rather old research and a lot of theorizing, which would probably be my two main points of criticism. I gave the book two stars on goodreads, but I should emphasize that this two star rating doesn’t really mean I think it’s a bad book; sometimes two star books are ‘borderline’, but this one isn’t and I found some of the coverage quite interesting. Given that the book explores how depression relates to interpersonal factors, I’ve of course read at least some stuff about many of the topics touched upon in the book before, e.g. here, here, here, here, and here. There was quite a bit of new stuff as well, though – in particular previous works dealing with depression which I’ve read have not had that much to say about how depression impacts people’s behaviours towards others and others’ behaviours towards the person who is depressed; the ‘interpersonal factors’ part of the coverage of previous works I’ve read on these topics has usually been limited to observations to the effect that lonely people are more likely to be depressed and similar, though the effects of social anxiety, often observed in depressed individuals (“the co-occurrence of depression and anxiety is very common. As many as 50% of people with major depression also experience an anxiety disorder” – a quote from the book), have admittedly also been pointed out to me before. This book however goes into more detail about these things and cover effects I do not recall having seen mentioned before.

Below I have added some observations from the book.

“There is good reason to emphasize the chronic nature of depression. First, some forms of depression, such as dysthymia, are chronic by definition (at least 2 years’ persistence in the case of dysthymia). Second, depression appears to be persistent within an episode, and, once it finally lets up, it tends to come back. Depression is both persistent within episodes and recurrent across episodes. […] Recurrence is defined as the reestablishment of clinical depression following a diagnosis-free period. […] Relapse is the resumption of symptoms in the vulnerable timeframe just following remission of a depressive episode. […] Several theorists have argued that depressive symptoms have a way of sustaining themselves. In this view, it is as if depression “feeds off itself,” “maintains its own momentum,” and “self-amplifies.” A key argument of this book is that these self-sustaining processes in depression may be interpersonal in nature. […] interpersonal factors are among the strongest predictors of depression chronicity. […] People with more interpersonal problems experience longer duration of depressive episodes”.

“Dysregulations of serotonin neurotransmitter systems, as well as of the hypothalamic-pituitary-adrenal axis (which regulates cortisol levels), have […] been proposed as a stable depression risk. There is little question that serotonin and cortisol levels are altered during depressive episodes (and related phenomena such as suicide). It is interesting to note that animals defeated in social skirmishes display behavioral and neurochemical similarities to depressed people […]. However, there is little persuasive evidence that dysregulation of these systems provides a full account of depression’s causes. [You can find some recent discussion of these topics, which also touches upon the observations included below, here] […] Regarding psychological explanations […], these theories can be grouped into those emphasizing cognitive vulnerability factors (e.g., pessimism), those emphasizing interpersonal vulnerability factors (e.g., excessive dependency), and those emphasizing personality-based vulnerability factors (e.g., high neuroticism, low extroversion). As with genetic—neurobiological explanations, psychological approaches have made some progress but cannot claim to provide a complete account of depression’s causes. […] shyness represents a stable vulnerability for depression. […] Although the notion that stable vulnerabilities like shyness only lead to depression in the context of some stressor is a reasonable view, it does not account for the finding that some shy (or otherwise vulnerable) people experience depression independent of negative life events. Partly in response to this quandary, a main purpose of this book is to explore interpersonal mechanisms whereby depression prolongs itself, even in the absence of external causes like negative life events.”

“there is some reason to suspect that depression’s properties may differ in certain subsets of people. Regarding late-life populations — for example, depressions that first occur in later life, as compared with those that first occur in early adulthood — occurrences may be about equally common in men and women (whereas “early” depressions are more common in women […]). In addition, late-life first occurrences are less associated with first-degree relatives’ depression risk […]; more related to neurological or medical disease […]; less severe […]; less associated with suicidal and anxious symptoms […]; and less related to personality problems, such as excessive dependency and avoidance […] Definitional problems plague depression research.”

“The incidence of clinical depression and depressive symptoms is two to three times higher among women than men. […] Although the gender differential in depression is consistent and well documented, little is known about the processes that underlie these differences.”

“In studies with follow-ups of 10 years or more, Coryell and Winokur (1992) found that 70% of people with one depressive episode subsequently experienced at least one more.”

“The link between life stress and depression is well-known — in general, the occurrence of life stressors appears to contribute to the development of depression […] Haramen (1991) theorized that depressed people are particularly stress-prone, in the sense that they actively generate negative life events. (It is important to distinguish active from intentional here — we do not believe that depressed people intentionally create problems for themselves, but that some of their behaviors have the unintended consequence of making life more stressful). If so, a self-sustaining process would be implicated in which formerly depressed people actively generate future life events that, in turn, sow the seeds of future depression. This would explain, at least in part, why depression persists and recurs. In a series of empirical studies, Hammen, Davila, Brown, Ellicott, and Gitlin, (1992) have documented the phenomenon of “stress generation.” […] In a 1-year study of women with depression, bipolar disorder, medical illness, or no disorder, Hammen (1991) showed that depressed women experienced more interpersonal stress to which the women themselves contributed (e.g., disputes with teachers or bosses; conflicts with children or partners), even compared with the women with bipolar disorder and medical illness. The finding was specific to interpersonal events — depressed women did not differ from others with regard to “fateful” events (i.e., those that really are randomly foisted on people). This result highlights the importance of interpersonal events, as well as the idea that nonrandom, self-produced negative events are characteristic of depressed people. Notably, the depressed women in Hammen’s (1991) study all experienced chronic forms of depression. This finding has been replicated in samples of men and women […] marital couples […] adolescent women […] children […] as well as by other research groups […] This line of research implicates the important possibility that, although depression may occur in the wake of stress, so may stress occur in depression’s wake.”

“Evidence suggests that people who are depressed demonstrate average problem-solving skills in impersonal settings (e.g., solving a puzzle), yet display specific problem-solving deficits in interpersonal settings […]. Examples of lapses in interpersonal problem solving may include the misperception of an offhand, trivial comment as an insulting attack; persistently avoiding someone who represents a key source of social support because of a minor misunderstanding; and angry, accusing confrontation of someone who was sincerely trying to help.”

“Many stress generation studies examine the links between self-reported depression and self-reported negative life stress. Because self-report is the source for assessment of both depression and stress, it is possible that increases in reported negative life events may merely reflect an increasingly hopeless outlook, rather than actual stress increases. A depressed person may thus perceive and report stress, even when stress is not actually present. […] the possible influence of increasing hopelessness in stress generation deserves attention […], especially insofar as hopelessness is a hallmark of major descriptive and etiological accounts of depression […] hopelessness, because of its embittering and stultifying effects on other people, may be particularly likely to disaffect others (i.e., to generate the stress of interpersonal rejection).”

“depression chronicity itself may be involved in stress generation. As depression persists, those who experience it may become more and more hopeless, and their significant others may become more and more burdened and disaffected. […] A second possibility is that hopelessness, because it has embittering and stultifying effects, may lead to cognitive representations of depressed people in the minds of significant others that are negative and change resistant. Sacco (1999) argued that once these representations are developed, they selectively guide attention and expectancies to confirm the representation. These social-cognitive processes may occur spontaneously and outside of awareness […] Once crystallized, cognitive representations of negative behaviors are more change resistant than representations of positive behaviors […]. Moreover, such representations gain momentum with use, in that they come to disproportionately influence social cognition relative to actual subsequent behaviors of the represented person […] With regard to others’ perceptions, the hopeless and potentially depressed person may face a very difficult problem: Continued hopelessness may only serve to maintain others’ negative views and thus generate stress in the form of criticism; positive changes, because they do not match others’ schemata, may be unnoticed or misattributed, leaving others’ negative representations unchanged.”

“there is accumulating evidence that depressed people actively generate their own stress, especially interpersonal stress […] For example, negative feedback-seeking (defined as the tendency to directly or indirectly invite criticism from other people and viewed as motivated by self-verification strivings […] represents a specific mechanism by which depression-prone people contribute to such stressors as relationship dissatisfaction and dissolution. Similarly, excessive reassurance-seeking (defined as the tendency to repeatedly and persistently demand assurance from others as to one’s lovability and worth, even after such is provided; […] also directly contributes to interpersonal stress. Interpersonal conflict avoidance ([…] defined as the anxious avoidance of self-assertion situations), also sows the seeds of stress generation. […] Research on self-handicapping and inoculation indicates that depressed people may gain self-protective and other rewards for depressive cognition and behavior. These rewards serve to maintain depressive cognition and behavior, and thereby [also] increase depression chronicity”.

[S]elf-verification theory […] proposes that people strive to attain and preserve predictable, certain, and familiar self-concepts. Further, the theory indicates that people accomplish this by actively seeking self-confirming interpersonal responses from those in their social environment. A key and perhaps counterintuitive implication of the theory is that there is no difference in the self-verification needs between people with positive self-concepts and people with negative self-concepts. […] In Study 1 [of Katz and Joiner (2002)], people in stable dating relationships were most intimate with and somewhat more committed to partners when they perceived that partners evaluated them as they evaluated themselves (even if negative). In Study 2, men reported the greatest esteem for same-sex roommates who evaluated them in a self-verifying manner (even if negative). Results from Study 2 were replicated and extended to both male and female roommate dyads in Study 3. […] In related research, it has been demonstrated that feedback that matches one’s self-concept is more “attention-grabbing,” more memorable, more rewarding, and more believable […]. In addition, a growing body of research suggests that people are more satisfied with and intimate in self-verifying relationships”.

“neither we nor self-verification theory imply that people enjoy the pain of abusive relationships and therefore seek them out. That is, self-verification theory is not talking about masochism. Rather, the theory points out the intractable dilemma of people with low self-esteem. If they choose (by whatever means, conscious or not) affirming relationships, relationship dysfunction, including abuse, may be in the cards. If they choose healthier relationships, they may have to grapple with the feeling that these relationships, despite their healthy qualities, do not provide them with self-confirmation. This represents a very difficult problem that has obvious effects on people’s well-being. […] there is growing evidence that people with depressive symptoms actively seek self-verification (i.e., negative feedback), often receive it, and may become depressed as a result. […] Depression may [also] perpetuate itself as a function of encouraging negative feedback-seeking. That is, people with depressive symptoms may solicit negative appraisals (and get them), and the receipt of negative feedback may serve to maintain or amplify their depression.”

“Coyne’s interpersonal theory of depression (1976b) proposed that in response to doubts as to their own worth or as to whether others truly care about them, initially nondepressed individuals may seek reassurance from others. Others may provide reassurance, but with little effect, because potentially depressed people doubt the reassurance, attributing it instead to others’ sense of pity or obligation. Potentially depressed people thus face a very difficult problem: They both need and doubt others’ reassurance. The need is emotionally powerful and thus may win out (at least temporarily), compelling the potentially depressed individuals to again “go back to the well” for reassurance from others; even if received, however, the reassurance is again doubted, and the pattern is repeated. Because the pattern is repetitive and resistant to change, the increasingly depressed persons’ significant others become confused, frustrated, and irritated and thus increasingly likely to reject the depressed persons and to become depressed themselves. […] We suggest that there is a considerable difference between the routine and adaptive solicitation of social support across distinct situations, and the repeated and persistent seeking of reassurance within the same situation, even when reassurance has already been provided.”

“Joiner and Katz (1999) reviewed the literature on contagious depression, and concluded that 40 findings from 36 separate studies provided substantial overall support for the proposition that depressed mood, and particularly, depressive symptoms, are contagious. […] excessive reassurance-seeking may explain, in part, when depression will be interpersonally transmitted. Taken together with research on interpersonal rejection, the work on contagious depression suggests that the joint operation of depressive symptoms and excessive reassurance-seeking disaffects significant others, by distancing them actually (e.g., ending the relationship) or functionally (e.g., emotional unavailability due to frustration or to contagious depression). […]  In the interpersonal arena, excessive reassurance-seeking and negative feedback-seeking compound one another by creating a particularly confusing and frustrating experience for relationship partners of depressed people. […] It is interesting to note that this process has been confirmed empirically: Joiner and Metalsky (1995) found that relationship partners of depressed people are particularly likely to evaluate them negatively if they engaged in both excessive reassurance-seeking and negative feedback-seeking.”

June 19, 2015 Posted by | Books, Psychology | Leave a comment

Wikipedia articles of interest

i. Motte-and-bailey castle (‘good article’).

“A motte-and-bailey castle is a fortification with a wooden or stone keep situated on a raised earthwork called a motte, accompanied by an enclosed courtyard, or bailey, surrounded by a protective ditch and palisade. Relatively easy to build with unskilled, often forced labour, but still militarily formidable, these castles were built across northern Europe from the 10th century onwards, spreading from Normandy and Anjou in France, into the Holy Roman Empire in the 11th century. The Normans introduced the design into England and Wales following their invasion in 1066. Motte-and-bailey castles were adopted in Scotland, Ireland, the Low Countries and Denmark in the 12th and 13th centuries. By the end of the 13th century, the design was largely superseded by alternative forms of fortification, but the earthworks remain a prominent feature in many countries. […]

Various methods were used to build mottes. Where a natural hill could be used, scarping could produce a motte without the need to create an artificial mound, but more commonly much of the motte would have to be constructed by hand.[19] Four methods existed for building a mound and a tower: the mound could either be built first, and a tower placed on top of it; the tower could alternatively be built on the original ground surface and then buried within the mound; the tower could potentially be built on the original ground surface and then partially buried within the mound, the buried part forming a cellar beneath; or the tower could be built first, and the mound added later.[25]

Regardless of the sequencing, artificial mottes had to be built by piling up earth; this work was undertaken by hand, using wooden shovels and hand-barrows, possibly with picks as well in the later periods.[26] Larger mottes took disproportionately more effort to build than their smaller equivalents, because of the volumes of earth involved.[26] The largest mottes in England, such as Thetford, are estimated to have required up to 24,000 man-days of work; smaller ones required perhaps as little as 1,000.[27] […] Taking into account estimates of the likely available manpower during the period, historians estimate that the larger mottes might have taken between four and nine months to build.[29] This contrasted favourably with stone keeps of the period, which typically took up to ten years to build.[30] Very little skilled labour was required to build motte and bailey castles, which made them very attractive propositions if forced peasant labour was available, as was the case after the Norman invasion of England.[19] […]

The type of soil would make a difference to the design of the motte, as clay soils could support a steeper motte, whilst sandier soils meant that a motte would need a more gentle incline.[14] Where available, layers of different sorts of earth, such as clay, gravel and chalk, would be used alternatively to build in strength to the design.[32] Layers of turf could also be added to stabilise the motte as it was built up, or a core of stones placed as the heart of the structure to provide strength.[33] Similar issues applied to the defensive ditches, where designers found that the wider the ditch was dug, the deeper and steeper the sides of the scarp could be, making it more defensive. […]

Although motte-and-bailey castles are the best known castle design, they were not always the most numerous in any given area.[36] A popular alternative was the ringwork castle, involving a palisade being built on top of a raised earth rampart, protected by a ditch. The choice of motte and bailey or ringwork was partially driven by terrain, as mottes were typically built on low ground, and on deeper clay and alluvial soils.[37] Another factor may have been speed, as ringworks were faster to build than mottes.[38] Some ringwork castles were later converted into motte-and-bailey designs, by filling in the centre of the ringwork to produce a flat-topped motte. […]

In England, William invaded from Normandy in 1066, resulting in three phases of castle building in England, around 80% of which were in the motte-and-bailey pattern. […] around 741 motte-and-bailey castles [were built] in England and Wales alone. […] Many motte-and-bailey castles were occupied relatively briefly and in England many were being abandoned by the 12th century, and others neglected and allowed to lapse into disrepair.[96] In the Low Countries and Germany, a similar transition occurred in the 13th and 14th centuries. […] One factor was the introduction of stone into castle building. The earliest stone castles had emerged in the 10th century […] Although wood was a more powerful defensive material than was once thought, stone became increasingly popular for military and symbolic reasons.”

ii. Battle of Midway (featured). Lots of good stuff in there. One aspect I had not been aware of beforehand was that Allied codebreakers also here (I was quite familiar with the works of Turing and others in Bletchley Park) played a key role:

“Admiral Nimitz had one priceless advantage: cryptanalysts had partially broken the Japanese Navy’s JN-25b code.[45] Since the early spring of 1942, the US had been decoding messages stating that there would soon be an operation at objective “AF”. It was not known where “AF” was, but Commander Joseph J. Rochefort and his team at Station HYPO were able to confirm that it was Midway; Captain Wilfred Holmes devised a ruse of telling the base at Midway (by secure undersea cable) to broadcast an uncoded radio message stating that Midway’s water purification system had broken down.[46] Within 24 hours, the code breakers picked up a Japanese message that “AF was short on water.”[47] HYPO was also able to determine the date of the attack as either 4 or 5 June, and to provide Nimitz with a complete IJN order of battle.[48] Japan had a new codebook, but its introduction had been delayed, enabling HYPO to read messages for several crucial days; the new code, which had not yet been cracked, came into use shortly before the attack began, but the important breaks had already been made.[49][nb 8]

As a result, the Americans entered the battle with a very good picture of where, when, and in what strength the Japanese would appear. Nimitz knew that the Japanese had negated their numerical advantage by dividing their ships into four separate task groups, all too widely separated to be able to support each other.[50][nb 9] […] The Japanese, by contrast, remained almost totally unaware of their opponent’s true strength and dispositions even after the battle began.[27] […] Four Japanese aircraft carriers — Akagi, Kaga, Soryu and Hiryu, all part of the six-carrier force that had attacked Pearl Harbor six months earlier — and a heavy cruiser were sunk at a cost of the carrier Yorktown and a destroyer. After Midway and the exhausting attrition of the Solomon Islands campaign, Japan’s capacity to replace its losses in materiel (particularly aircraft carriers) and men (especially well-trained pilots) rapidly became insufficient to cope with mounting casualties, while the United States’ massive industrial capabilities made American losses far easier to bear. […] The Battle of Midway has often been called “the turning point of the Pacific”.[140] However, the Japanese continued to try to secure more strategic territory in the South Pacific, and the U.S. did not move from a state of naval parity to one of increasing supremacy until after several more months of hard combat.[141] Thus, although Midway was the Allies’ first major victory against the Japanese, it did not radically change the course of the war. Rather, it was the cumulative effects of the battles of Coral Sea and Midway that reduced Japan’s ability to undertake major offensives.[9]

One thing which really strikes you (well, struck me) when reading this stuff is how incredibly capital-intensive the war at sea really was; this was one of the most important sea battles of the Second World War, yet the total Japanese death toll at Midway was just 3,057. To put that number into perspective, it is significantly smaller than the average number of people killed each day in Stalingrad (according to one estimate, the Soviets alone suffered 478,741 killed or missing during those roughly 5 months (~150 days), which comes out at roughly 3000/day).

iii. History of time-keeping devices (featured). ‘Exactly what it says on the tin’, as they’d say on TV Tropes.

Clepsydra-Diagram-Fancy
It took a long time to get from where we were to where we are today; the horologists of the past faced a lot of problems you’ve most likely never even thought about. What do you do for example do if your ingenious water clock has trouble keeping time because variation in water temperature causes issues? Well, you use mercury instead of water, of course! (“Since Yi Xing’s clock was a water clock, it was affected by temperature variations. That problem was solved in 976 by Zhang Sixun by replacing the water with mercury, which remains liquid down to −39 °C (−38 °F).”).

iv. Microbial metabolism.

Microbial metabolism is the means by which a microbe obtains the energy and nutrients (e.g. carbon) it needs to live and reproduce. Microbes use many different types of metabolic strategies and species can often be differentiated from each other based on metabolic characteristics. The specific metabolic properties of a microbe are the major factors in determining that microbe’s ecological niche, and often allow for that microbe to be useful in industrial processes or responsible for biogeochemical cycles. […]

All microbial metabolisms can be arranged according to three principles:

1. How the organism obtains carbon for synthesising cell mass:

2. How the organism obtains reducing equivalents used either in energy conservation or in biosynthetic reactions:

3. How the organism obtains energy for living and growing:

In practice, these terms are almost freely combined. […] Most microbes are heterotrophic (more precisely chemoorganoheterotrophic), using organic compounds as both carbon and energy sources. […] Heterotrophic microbes are extremely abundant in nature and are responsible for the breakdown of large organic polymers such as cellulose, chitin or lignin which are generally indigestible to larger animals. Generally, the breakdown of large polymers to carbon dioxide (mineralization) requires several different organisms, with one breaking down the polymer into its constituent monomers, one able to use the monomers and excreting simpler waste compounds as by-products, and one able to use the excreted wastes. There are many variations on this theme, as different organisms are able to degrade different polymers and secrete different waste products. […]

Biochemically, prokaryotic heterotrophic metabolism is much more versatile than that of eukaryotic organisms, although many prokaryotes share the most basic metabolic models with eukaryotes, e. g. using glycolysis (also called EMP pathway) for sugar metabolism and the citric acid cycle to degrade acetate, producing energy in the form of ATP and reducing power in the form of NADH or quinols. These basic pathways are well conserved because they are also involved in biosynthesis of many conserved building blocks needed for cell growth (sometimes in reverse direction). However, many bacteria and archaea utilize alternative metabolic pathways other than glycolysis and the citric acid cycle. […] The metabolic diversity and ability of prokaryotes to use a large variety of organic compounds arises from the much deeper evolutionary history and diversity of prokaryotes, as compared to eukaryotes. […]

Many microbes (phototrophs) are capable of using light as a source of energy to produce ATP and organic compounds such as carbohydrates, lipids, and proteins. Of these, algae are particularly significant because they are oxygenic, using water as an electron donor for electron transfer during photosynthesis.[11] Phototrophic bacteria are found in the phyla Cyanobacteria, Chlorobi, Proteobacteria, Chloroflexi, and Firmicutes.[12] Along with plants these microbes are responsible for all biological generation of oxygen gas on Earth. […] As befits the large diversity of photosynthetic bacteria, there are many different mechanisms by which light is converted into energy for metabolism. All photosynthetic organisms locate their photosynthetic reaction centers within a membrane, which may be invaginations of the cytoplasmic membrane (Proteobacteria), thylakoid membranes (Cyanobacteria), specialized antenna structures called chlorosomes (Green sulfur and non-sulfur bacteria), or the cytoplasmic membrane itself (heliobacteria). Different photosynthetic bacteria also contain different photosynthetic pigments, such as chlorophylls and carotenoids, allowing them to take advantage of different portions of the electromagnetic spectrum and thereby inhabit different niches. Some groups of organisms contain more specialized light-harvesting structures (e.g. phycobilisomes in Cyanobacteria and chlorosomes in Green sulfur and non-sulfur bacteria), allowing for increased efficiency in light utilization. […]

Most photosynthetic microbes are autotrophic, fixing carbon dioxide via the Calvin cycle. Some photosynthetic bacteria (e.g. Chloroflexus) are photoheterotrophs, meaning that they use organic carbon compounds as a carbon source for growth. Some photosynthetic organisms also fix nitrogen […] Nitrogen is an element required for growth by all biological systems. While extremely common (80% by volume) in the atmosphere, dinitrogen gas (N2) is generally biologically inaccessible due to its high activation energy. Throughout all of nature, only specialized bacteria and Archaea are capable of nitrogen fixation, converting dinitrogen gas into ammonia (NH3), which is easily assimilated by all organisms.[14] These prokaryotes, therefore, are very important ecologically and are often essential for the survival of entire ecosystems. This is especially true in the ocean, where nitrogen-fixing cyanobacteria are often the only sources of fixed nitrogen, and in soils, where specialized symbioses exist between legumes and their nitrogen-fixing partners to provide the nitrogen needed by these plants for growth.

Nitrogen fixation can be found distributed throughout nearly all bacterial lineages and physiological classes but is not a universal property. Because the enzyme nitrogenase, responsible for nitrogen fixation, is very sensitive to oxygen which will inhibit it irreversibly, all nitrogen-fixing organisms must possess some mechanism to keep the concentration of oxygen low. […] The production and activity of nitrogenases is very highly regulated, both because nitrogen fixation is an extremely energetically expensive process (16–24 ATP are used per N2 fixed) and due to the extreme sensitivity of the nitrogenase to oxygen.” (A lot of the stuff above was of course for me either review or closely related to stuff I’ve already read in the coverage provided in Beer et al., a book I’ve talked about before here on the blog).

v. Uranium (featured). It’s hard to know what to include here as the article has a lot of stuff, but I found this part in particular, well, interesting:

“During the Cold War between the Soviet Union and the United States, huge stockpiles of uranium were amassed and tens of thousands of nuclear weapons were created using enriched uranium and plutonium made from uranium. Since the break-up of the Soviet Union in 1991, an estimated 600 short tons (540 metric tons) of highly enriched weapons grade uranium (enough to make 40,000 nuclear warheads) have been stored in often inadequately guarded facilities in the Russian Federation and several other former Soviet states.[12] Police in Asia, Europe, and South America on at least 16 occasions from 1993 to 2005 have intercepted shipments of smuggled bomb-grade uranium or plutonium, most of which was from ex-Soviet sources.[12] From 1993 to 2005 the Material Protection, Control, and Accounting Program, operated by the federal government of the United States, spent approximately US $550 million to help safeguard uranium and plutonium stockpiles in Russia.[12] This money was used for improvements and security enhancements at research and storage facilities. Scientific American reported in February 2006 that in some of the facilities security consisted of chain link fences which were in severe states of disrepair. According to an interview from the article, one facility had been storing samples of enriched (weapons grade) uranium in a broom closet before the improvement project; another had been keeping track of its stock of nuclear warheads using index cards kept in a shoe box.[45]

Some other observations from the article below:

“Uranium is a naturally occurring element that can be found in low levels within all rock, soil, and water. Uranium is the 51st element in order of abundance in the Earth’s crust. Uranium is also the highest-numbered element to be found naturally in significant quantities on Earth and is almost always found combined with other elements.[10] Along with all elements having atomic weights higher than that of iron, it is only naturally formed in supernovae.[46] The decay of uranium, thorium, and potassium-40 in the Earth’s mantle is thought to be the main source of heat[47][48] that keeps the outer core liquid and drives mantle convection, which in turn drives plate tectonics. […]

Natural uranium consists of three major isotopes: uranium-238 (99.28% natural abundance), uranium-235 (0.71%), and uranium-234 (0.0054%). […] Uranium-238 is the most stable isotope of uranium, with a half-life of about 4.468×109 years, roughly the age of the Earth. Uranium-235 has a half-life of about 7.13×108 years, and uranium-234 has a half-life of about 2.48×105 years.[82] For natural uranium, about 49% of its alpha rays are emitted by each of 238U atom, and also 49% by 234U (since the latter is formed from the former) and about 2.0% of them by the 235U. When the Earth was young, probably about one-fifth of its uranium was uranium-235, but the percentage of 234U was probably much lower than this. […]

Worldwide production of U3O8 (yellowcake) in 2013 amounted to 70,015 tonnes, of which 22,451 t (32%) was mined in Kazakhstan. Other important uranium mining countries are Canada (9,331 t), Australia (6,350 t), Niger (4,518 t), Namibia (4,323 t) and Russia (3,135 t).[55] […] Australia has 31% of the world’s known uranium ore reserves[61] and the world’s largest single uranium deposit, located at the Olympic Dam Mine in South Australia.[62] There is a significant reserve of uranium in Bakouma a sub-prefecture in the prefecture of Mbomou in Central African Republic. […] Uranium deposits seem to be log-normal distributed. There is a 300-fold increase in the amount of uranium recoverable for each tenfold decrease in ore grade.[75] In other words, there is little high grade ore and proportionately much more low grade ore available.”

vi. Radiocarbon dating (featured).

Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method of determining the age of an object containing organic material by using the properties of radiocarbon (14C), a radioactive isotope of carbon. The method was invented by Willard Libby in the late 1940s and soon became a standard tool for archaeologists. Libby received the Nobel Prize for his work in 1960. The radiocarbon dating method is based on the fact that radiocarbon is constantly being created in the atmosphere by the interaction of cosmic rays with atmospheric nitrogen. The resulting radiocarbon combines with atmospheric oxygen to form radioactive carbon dioxide, which is incorporated into plants by photosynthesis; animals then acquire 14C by eating the plants. When the animal or plant dies, it stops exchanging carbon with its environment, and from that point onwards the amount of 14C it contains begins to reduce as the 14C undergoes radioactive decay. Measuring the amount of 14C in a sample from a dead plant or animal such as piece of wood or a fragment of bone provides information that can be used to calculate when the animal or plant died. The older a sample is, the less 14C there is to be detected, and because the half-life of 14C (the period of time after which half of a given sample will have decayed) is about 5,730 years, the oldest dates that can be reliably measured by radiocarbon dating are around 50,000 years ago, although special preparation methods occasionally permit dating of older samples.

The idea behind radiocarbon dating is straightforward, but years of work were required to develop the technique to the point where accurate dates could be obtained. […]

The development of radiocarbon dating has had a profound impact on archaeology. In addition to permitting more accurate dating within archaeological sites than did previous methods, it allows comparison of dates of events across great distances. Histories of archaeology often refer to its impact as the “radiocarbon revolution”.”

I’ve read about these topics before in a textbook setting (e.g. here), but/and I should note that the article provides quite detailed coverage and I think most people will encounter some new information by having a look at it even if they’re superficially familiar with this topic. The article has a lot of stuff about e.g. ‘what you need to correct for’, which some of you might find interesting.

vii. Raccoon (featured). One interesting observation from the article:

“One aspect of raccoon behavior is so well known that it gives the animal part of its scientific name, Procyon lotor; “lotor” is neo-Latin for “washer”. In the wild, raccoons often dabble for underwater food near the shore-line. They then often pick up the food item with their front paws to examine it and rub the item, sometimes to remove unwanted parts. This gives the appearance of the raccoon “washing” the food. The tactile sensitivity of raccoons’ paws is increased if this rubbing action is performed underwater, since the water softens the hard layer covering the paws.[126] However, the behavior observed in captive raccoons in which they carry their food to water to “wash” or douse it before eating has not been observed in the wild.[127] Naturalist Georges-Louis Leclerc, Comte de Buffon, believed that raccoons do not have adequate saliva production to moisten food thereby necessitating dousing, but this hypothesis is now considered to be incorrect.[128] Captive raccoons douse their food more frequently when a watering hole with a layout similar to a stream is not farther away than 3 m (10 ft).[129] The widely accepted theory is that dousing in captive raccoons is a fixed action pattern from the dabbling behavior performed when foraging at shores for aquatic foods.[130] This is supported by the observation that aquatic foods are doused more frequently. Cleaning dirty food does not seem to be a reason for “washing”.[129] Experts have cast doubt on the veracity of observations of wild raccoons dousing food.[131]

And here’s another interesting set of observations:

“In Germany—where the racoon is called the Waschbär (literally, “wash-bear” or “washing bear”) due to its habit of “dousing” food in water—two pairs of pet raccoons were released into the German countryside at the Edersee reservoir in the north of Hesse in April 1934 by a forester upon request of their owner, a poultry farmer.[186] He released them two weeks before receiving permission from the Prussian hunting office to “enrich the fauna.” [187] Several prior attempts to introduce raccoons in Germany were not successful.[188] A second population was established in eastern Germany in 1945 when 25 raccoons escaped from a fur farm at Wolfshagen, east of Berlin, after an air strike. The two populations are parasitologically distinguishable: 70% of the raccoons of the Hessian population are infected with the roundworm Baylisascaris procyonis, but none of the Brandenburgian population has the parasite.[189] The estimated number of raccoons was 285 animals in the Hessian region in 1956, over 20,000 animals in the Hessian region in 1970 and between 200,000 and 400,000 animals in the whole of Germany in 2008.[158][190] By 2012 it was estimated that Germany now had more than a million raccoons.[191]

June 14, 2015 Posted by | Archaeology, Biology, Botany, Geology, History, Microbiology, Physics, Wikipedia, Zoology | Leave a comment

A few lectures

This one is not quite new, but I have never seen it or blogged it before. The sound is not completely optimal and as is so often the case for lectures like these it’s at times slightly annoying that you can’t tell what she’s pointing at when she’s talking about the slides, but these issues are relatively minor and should not keep you from watching the lecture.

This is a really nice introduction to some main ideas in the Nimzo Indian defence.

June 10, 2015 Posted by | Astronomy, Chess, Lectures | Leave a comment

Photosynthesis in the Marine Environment (I)

I’m currently reading this book. Below some observations from part 1.

“The term autotroph is usually associated with the photosynthesising plants (including algae and cyanobacteria) and heterotroph with animals and some other groups of organisms that need to be provided high-energy containing organic foods (e.g. the fungi and many bacteria). However, many exceptions exist: Some plants are parasitic and may be devoid of chlorophyll and, thus, lack photosynthesis altogether6, and some animals contain chloroplasts or photosynthesising algae or
cyanobacteria and may function, in part, autotrophically; some corals rely on the photosynthetic algae within their bodies to the extent that they don’t have to eat at all […] If some plants are heterotrophic and some animals autotrophic, what then differentiates plants from animals? It is usually said that what differs the two groups is the absence (animals) or presence (plants) of a cell wall. The cell wall is deposited outside the cell membrane in plants, and forms a type of exo-skeleton made of polysaccharides (e.g. cellulose or agar in some red algae, or silica in the case of diatoms) that renders rigidity to plant cells and to the whole plant.”

“For the autotrophs, […] there was an advantage if they could live close to the shores where inorganic nutrient concentrations were higher (because of mineral-rich runoffs from land) than in the upper water layer of off-shore locations. However, living closer to shore also meant greater effects of wave action, which would alter, e.g. the light availability […]. Under such conditions, there would be an advantage to be able to stay put in the seawater, and under those conditions it is thought that filamentous photosynthetic organisms were formed from autotrophic cells (ca. 650 million years ago), which eventually resulted in macroalgae (some 450 million years ago) featuring holdfast tissues that could adhere them to rocky substrates. […] Very briefly now, the green macroalgae were the ancestors of terrestrial plants, which started to invade land ca. 400 million years ago (followed by the animals).”

“Marine ‘plants’ (= all photoautotrophic organisms of the seas) can be divided into phytoplankton (‘drifters’, mostly unicellular) and phytobenthos (connected to the bottom, mostly multicellular/macroscopic).
The phytoplankton can be divided into cyanobacteria (prokaryotic) and microalgae (eukaryotic) […]. The phytobenthos can be divided into macroalgae and seagrasses (marine angiosperms, which invaded the shallow seas some 90 million years ago). The micro- and macro-algae are divided into larger groups as based largely on their pigment composition [e.g. ‘red algae‘, ‘brown algae‘, …]

There are some 150 currently recognised species of marine cyanobacteria, ∼20 000 species of eukaryotic microalgae, several thousand species of macroalgae and 50(!) species of seagrasses. Altogether these marine plants are accountable for approximately half of Earth’s photosynthetic (or primary) production.

The abiotic factors that are conducive to photosynthesis and plant growth in the marine environment differ from those of terrestrial environments mainly with regard to light and inorganic carbon (Ci) sources. Light is strongly attenuated in the marine environment by absorption and scatter […] While terrestrial plants rely of atmospheric CO2 for their photosynthesis, marine plants utilise largely the >100 times higher concentration of HCO3 as the main Ci source for their photosynthetic needs. Nutrients other than CO2, that may limit plant growth in the marine environment include nitrogen (N), phosphorus (P), iron (Fe) and, for the diatoms, silica (Si).”

“The conversion of the plentiful atmospheric N2 gas (∼78% in air) into bio-available N-rich cellular constituents is a fundamental process that sustains life on Earth. For unknown reasons this process is restricted to selected representatives among the prokaryotes: archaea and bacteria. N2 fixing organisms, also termed diazotrophs (dia = two; azo = nitrogen), are globally wide-spread in terrestrial and aquatic environments, from polar regions to hot deserts, although their abundance varies widely. [Why is nitrogen important, I hear you ask? Well, when you hear the word ‘nitrogen’ in biology texts, think ‘protein’ – “Because nitrogen is relatively easy to measure and protein is not, protein content is often estimated by assaying organic nitrogen, which comprises from 15 to 18% of plant proteins” (Herrera et al.see this post]. […] . Cyanobacteria dominate marine diazotrophs and occupy large segments of marine open waters […]  sustained N2 fixation […] is a highly energy-demanding process. […] in all diazotrophs, the nitrogenase enzyme complex […] of marine cyanobacteria requires high Fe levels […] Another key nutrient is phosphorus […] which has a great impact on growth and N2 fixation in marine cyanobacteria. […] Recent model-based estimates of N2 fixation suggest that unicellular cyanobacteria contribute significantly to global ocean N budgets.”

“For convenience, we often divide the phytoplankton into different size classes, the pico-phytoplankton (0.2–2 μm effective cell diameter, ECD4); the nanophytoplankton (2–20 μm ECD) and the microphytoplankton (20–200 μm ECD). […] most of the major marine microalgal groups are found in all three size classes […] a 2010 paper estimate that these plants utilise 46 Gt carbon yearly, which can be divided into 15 Gt for the microphytoplankton, 20 Gt for the nanophytoplankton and 11 Gt for the picophytoplankton. Thus, the very small (nano- + pico-forms) of phytoplankton (including cyanobacterial forms) contribute 2/3 of the overall planktonic production (which, again, constitutes about half of the global production”).

“Many primarily non-photosynthetic organisms have developed symbioses with microalgae and cyanobacteria; these photosynthetic intruders are here referred to as photosymbionts. […] Most photosymbionts are endosymbiotic (living within the host) […] In almost all cases, these micro-algae are in symbiosis with invertebrates. Here the alga provides the animal with organic products of photosynthesis, while the invertebrate host can supply CO2 and other inorganic nutrients including nitrogen and phosphorus to the alga […]. In cases where cyanobacteria form the photosymbiont, their ‘caloric’ nutritional value is more questionable, and they may instead produce toxins that deter other animals from eating the host […] Many reef-building […] corals contain symbiotic zooxanthellae within the digestive cavity of their polyps, and in general corals that have symbiotic algae grow much faster than those without them. […] The loss of zooxanthellae from the host is known as coral bleaching […] Certain sea slugs contain functional chloroplasts that were ingested (but not digested) as part of larger algae […]. After digesting the rest of the alga, these chloroplasts are imbedded within the slugs’ digestive tract in a process called kleptoplasty (the ‘stealing’ of plastids). Even though this is not a true symbiosis (the chloroplasts are not organisms and do not gain anything from the association), the photosynthetic activity aids in the nutrition of the slugs for up to several months, thus either complementing their nutrition or carrying them through periods when food is scarce or absent.”

“90–100 million years ago, when there was a rise in seawater levels, some of the grasses that grew close to the seashores found themselves submerged in seawater. One piece of evidence that supports [the] terrestrial origin [of marine angiosperms] can be seen in the fact that residues of stomata can be found at the base of the leaves. In terrestrial plants, the stomata restrict water loss from the leaves, but since seagrasses are principally submerged in a liquid medium, the stomata became absent in the bulk parts of the leaves. These marine angiosperms, or seagrasses, thus evolved from those coastal grasses that successfully managed to adapt to being submerged in saline waters. Another theory has it that the ancestors of seagrasses were freshwater plants that, therefore, only had to adapt to water of a higher salinity. In both cases, the seagrasses exemplify a successful readaptation to marine life […] While there may exist some 20 000 or more species of macroalgae […], there are only some 50 species of seagrasses, most of which are found in tropical seas. […] the ability to extract nutrients from the sediment renders the seagrasses at an advantage over (the root-less) macroalgae in nutrient-poor waters. […] one of the basic differences in habitat utilisation between macroalgae and seagrasses is that the former usually grow on rocky substrates where they are held in place by their holdfasts, while seagrasses inhabit softer sediments where they are held in place by their root systems. Unlike macroalgae, where the whole plant surface is photosynthetically active, large proportions of seagrass plants are comprised of the non-photosynthetic roots and rhizomes. […] This means […] that seagrasses need more light in order to survive than do many algae […] marine plants usually contain less structural tissues than their terrestrial counterparts”.

“if we define ‘visible light’ as the electromagnetic wave upon which those energy-containing particles called quanta ‘ride’ that cause vision in higher animals (those quanta are also called photons) and compare it with light that causes photosynthesis, we find, interestingly, that the two processes use approximately the same wavelengths: While mammals largely use the 380–750 nm (nm = 10-9 m) wavelength band for vision, plants use the 400–700-nm band for photosynthesis; the latter is therefore also termed photosynthetically active radiation (PAR […] If a student
asks “but how come that animals and plants use almost identical wavelengths of radiation for so very different purposes?”, my answer is “sorry, but we don’t have the time to discuss that now”, meaning that while I think it has to do with too high and too low quantum energies below and above those wavelengths, I really don’t know.”

“energy (E) of a photon is inversely proportional to its wavelength […] a blue photon of 400 nm wavelength contains almost double the energy of a red one of 700 nm, while the photons of PAR between those two extremes carry decreasing energies as wavelengths increase. Accordingly, low-energy photons (i.e. of high wavelengths, e.g. those of reddish light) are absorbed to a greater extent by water molecules along a depth gradient than are photons of higher energy (i.e. lower wavelengths, e.g. bluish light), and so the latter penetrate deeper down in clear oceanic waters […] In water, the spectral distribution of PAR reaching a plant is different from that on land. This is because water not only attenuates the light intensity (or, more correctly, the photon flux, or irradiance […]), but, as mentioned above and detailed below, the attenuation with depth is wavelength dependent; therefore, plants living in the oceans will receive different spectra of light dependent on depth […] The two main characteristics of seawater that determine the quantity and quality of the irradiance penetrating to a certain depth are absorption and scatter. […] Light absorption in the oceans is a property of the water molecules, which absorb photons according to their energy […] Thus, red photons of low energy are more readily absorbed than, e.g. blue ones; only <1% of the incident red photons (calculated for 650 nm) penetrate to 20 m depth in clear waters while some 60% of the blue photons (450 nm) remain at that depth. […] Scatter […] is mainly caused by particles suspended in the water column (rather than by the water molecules themselves, although they too scatter light a little). Unlike absorption, scatter affects short-wavelength photons more than long-wavelength ones […] in turbid waters, photons of decreasing wavelengths are increasingly scattered. Since water molecules are naturally also present, they absorb the higher wavelengths, and the colours penetrating deepest in turbid waters are those between the highly scattered blue and highly absorbed red, e.g. green. The greenish colour of many coastal waters is therefore often due not only to the presence of chlorophyll-containing phytoplankton, but because, again, reddish photons are absorbed, bluish photons are scattered, and the midspectrum (i.e. green) fills the bulk part of the water column.”

“the open ocean, several kilometres or miles from the shore, almost always appears as blue. The reason for this is that in unpolluted, particle-free, waters, the preferential absorption of long-wavelength (low-energy) photons is what mainly determines the spectral distribution of light attenuation. Thus, short-wavelength (high-energy) bluish photons penetrate deepest and ‘fill up’ the bulk of the water column with their colour. Since water molecules also scatter a small proportion of those photons […], it follows that these largely water-penetrating photons are eventually also reflected back to our eyes. Or, in other words, out of the very low scattering in clear oceanic waters, the photons available to be scattered and, thus, reflected to our eyes, are mainly the bluish ones, and that is why the clear deep oceans look blue. (It is often said that the oceans are blue because the blue sky is reflected by the water surface. However, sailors will testify to the truism that the oceans are also deep blue in heavily overcast weathers, and so that explanation of the general blueness of the oceans is not valid.)”

“Although marine plants can be found in a wide range of temperature regimes, from the tropics to polar regions, the large bodies of water that are the environment for most marine plants have relatively constant temperatures, at least on a day-to-day basis. […] For marine plants that are found in intertidal regions, however, temperature variation during a single day can be very high as the plants find themselves alternately exposed to air […] Marine plants from tropical and temperate regions tend to have distinct temperature ranges for growth […] and growth optima. […] among most temperate species of microalgae, temperature optima for growth are in the range 18–25 ◦C, while some Antarctic diatoms show optima at 4–6 ◦C with no growth above a critical temperature of 7–12 ◦C. By contrast, some tropical diatoms will not grow below 15–17 ◦C. Similar responses are found in macroalgae and seagrasses. However, although some marine plants have a restricted temperature range for growth (so-called stenothermal species; steno = narrow and thermal relates to temperature), most show some growth over a broad range of temperatures and can be considered eurythermal (eury = wide).”

June 4, 2015 Posted by | Biology, Books, Botany, Ecology, Evolutionary biology, Microbiology, Physics, Zoology | Leave a comment

(10.000) Words…

“The language denotes the man. A coarse or refined character finds its expression naturally in a coarse or refined phraseology.” (Christian Nestell Bovee)

10.000

(Click to view details/full size)

Doff, pabulum, astringent, enervate, mountebank, argot, sluice, sequin, indite, vitiate, simper, tarry, casuistry, saturnine, sidle, meretricious, fugacious, esurient, scabrous, disquisition, winsome, sedulous, badinage, abeyance, effrontery, minatory, synecdoche, lubricious, adjure, asperse, encumbrance, careen, desuetude, syllepsis, limn, bathetic, surcease, taut, tribulation, chrysalis, farrier, vane, virago, rictus, gewgaw, vituperate, curdleichthyology, abrogate, stultify, approbatory, intrepid, nugatory, contumacious, append, vociferate, tenebrous, arrogate, vermilion, descry, sententious, repine, procrustean, undulate, abstemious, palter, iniquitous, endue, lugubrious, obloquy, obdurate, importunate, apotheosis, obviateperegrinate, sacrum, …

In a way it makes absolutely no sense for someone like me to spend as much time on this stuff as I have over the last year or two; I almost never engage in conversations with other people as I rarely interact with other people at all (and also tend to avoid conversations when I do because conversations are usually unpleasant), and when I do both interact and converse with other people I only rarely engage in conversations in English as my first language, and the first language of most of the people with whom I interact regularly, is Danish. If the aim were to improve my vocabulary in order to hide my stupidity (‘make me look smarter’), I’d do a lot better by learning some more fancy-sounding Danish words. As it is, I can’t even remember the last time I last looked up a word in a Danish dictionary, but it’s been at least a few years (if not much more than that). Of course on the other hand I do read a lot of books, and I only read books in English. So it’s probably not a complete waste of time. But I’ve been thinking lately that I might derive a lot more benefit from these sorts of activities, in the sense that more words would ‘stick’, if I actually had to interact with other people in English on a daily basis. It seems to me likely that in a sense my language production capabilities might not be improved as much by these activities as are my language consumption capabilities. What I mean by this is that I frequently encounter new words I’ve worked on in the books I read, but at the same time I’m very rarely forced to ever actually use any of them in conversations with other people, so I don’t. I don’t know enough about linguistics to tell if this distinction between production and consumption matters, but it seems to me that it might. On a related note I’ve recently had the idea that my activities in these areas might implicitly be lowering my opportunity costs of book-reading, compared to personal interactions with others, because these activities make it easier for me to read books but does not at the same time much improve upon my social skills (e.g. conversational skills; though I’m on a related note open to the suggestion that conversational skills and vocabulary size are in some contexts relevant to this discussion in fact perhaps best conceived of as orthogonal variables (which doesn’t help at all…)) – which is hardly what I would conceive of as a desirable outcome. Oh well.

As you should have been able to infer from the screencap above and/or the post title, I’ve by now reached another major milestone (here’s the first one) on the vocabulary.com site as I have now ‘mastered’ more than 10.000 words on the site – I figured it made sense to make a post about this and related matters, and this is the post in question. In the time that has passed since I wrote the post to which I link above the site has undergone a few minor changes, but actually most of it works pretty much the same way it did last year; if you’re curious about how the vocabulary.com site works and you have not heard about it before, go have a look at that post before reading on. As I have noted before I don’t fully trust the vocabulary.com dictionary; or at least I like Webster’s online dictionary better, which is why the links above are all to Webster entries. I’ll often ‘check out’ particular words which I’m curious about after having encountered them on vocabulary.com, because sometimes specific interpretations of the words in question are simply wrong, or at least so I would argue; if the site is trying to tell me that a specific word means X, but I ‘know’ that it doesn’t and the Webster entry also provides zero support for this specific usage/interpretation – or actively ‘disagrees’ – then I go with Webster and I’ll get annoyed at the people behind vocabulary.com (again). One thing to note when making comparisons here is that in general I believe that the vocabulary.com dictionary has a greater ‘range’ of meanings covered, which also means that if you look up the entries to which I link above you might fail to appreciate how many different types of questions that might be required for someone to ‘master’ the words on vocabulary.com; if the word has some rare meaning in a very specific context, you can expect vocabulary.com to ask you about that before you master the word (and you can expect a subset of those questions to be poorly worded, making you angry at the programmers behind the site). This also means that even if you think you know a word, the site may still cause you some challenges along the way.

I’ve used the site pretty much every week during the last year, though in some periods I used the site very little; the relative inactivity meant that I dropped out of the top 100 list for a while, but over the last weeks I’ve done some more work on the site, and I’m now back in the top 100. So I seem to focus more on improving my vocabulary than do most users on the site, which I actually find somewhat curious given that this tool has apparently been introduced to thousands of children throughout the US. On the other hand I’ve put in a lot of hours when you add them all together (the site actually logging the hours you put in is incidentally a new feature which was not present when I posted my first couple of posts about the site a year ago; I actually didn’t like this feature to start with, in part because I realized how much time I’d spent on this stuff).

The site is in my opinion very bad at explaining how to properly use the site to learn new words in the semi-long run, so I should probably explain why I recently came to ‘rediscover’ my joy of using the site. The main factor rekindling my interest was that I discovered how to use ‘lists’ to focus on new words. If you play the challenge without any bells and whistles and never add lists or anything, you’ll at some point get to a situation where you may well be given 500 questions without ‘mastering’ more than one or two new words; the site will recycle and recycle, asking you hundreds of questions about words you’ve already mastered and occasionally ask you about a new word which you’ll never get enough questions about to actually ever master – this is incredibly frustrating, to the point where I last year decided to send the vocabulary.com staff an email suggesting they make changes to the algorithms, because this just seemed insane and probably killed the motivation for a lot of users. You’d put in 20 hours almost without being allowed to actually achieve mastery of any of the new words, then suddenly you’d ‘master’ more than a thousand words one after the other because now suddenly the site could be bothered to finally allow you to show that you’ve mastered those words the site last asked you about last April – or whenever. Or not – I have a suspicion that a lot of users have given up before this point was reached and just said ‘screw this’ before getting to the mastery questions at the end of the line, and that stuff like this may be part of the reason why I’m in the top 100 list now. If this is true it’s sort of sad, because it seems like such a big missed opportunity; what you’d ideally want is not just a site useful for learning a few thousand words after which the way the site is coded will contribute strongly to making many people sick of it, but rather a site which mixes new words and old in an optimal manner which might encourage users to keep using the site in the long run. People may argue about what’s an optimal mix, but I don’t think you can argue with a straight face that the current configuration is anywhere near this point – and if the perceived optimal mix is different for different people, why not allow users to have an influence on this variable in the first place? In a way the site implicitly does, in an admittedly roundabout manner, give people some influence on these sorts of variables via the lists, but I remained unaware of this for a very long time so a lot of users presumably don’t know this. Either way I certainly think I’m justified in assuming that far more care has been taken to optimize the user experience early on than has been taken to making sure the site remains useful even to people who’ve already mastered a lot of words; I’d argue that the site has an excessive focus on review questions, compared to questions about new words, and from personal experience it has seemed to me that this problem seems to get bigger and bigger the more words you learn.

Adding to the problems mentioned above it also does not help that some of the review questions – not many of them, but some – are so poorly thought out that you can’t really tell what the right answer is supposed to be despite knowing very well what the word means, so you risk getting stuck in loops where a substantial proportion of the questions you’re asked are about words you already know at least in part because the questions are bad (if you answer a tricky review question like that incorrectly, you’ll be given quite a few more other questions in the future about this word you don’t care about and don’t want to answer questions about anymore, because an incorrect answer to a review question is always taken by the site as an indication that you don’t understand the word as well as you should, and never as an indication that someone should seriously have a closer look at some of those shitty questions (again, there aren’t that many of them, but they’re very annoying to someone like me)).

So in short, if you’re contemplating using the site or already does, don’t do what I did – instead of just playing the basic challenge, at some point it becomes necessary to instead start exploring the lists. If you add a list to learn, the site will mostly (though not exclusively) focus on the words on the list you’re currently learning, avoiding the outcome outlined above. You can add more than one list simultaneously. I’ll put it bluntly – if you don’t use lists, this site will eventually kill pretty much all desire to use it, because you’ll eventually get to a point where you’ll feel you’re not making any progress and you’ll also at the same time have the distinct impression that the site actively refuses to give you any opportunities to making progress. I can’t be the only person who until recently did not use lists, and frankly without lists this site is a disaster waiting to happen. If you use lists well, it is however a very useful tool.

The site does not help you with grammar – if you know about a site that does, I’d be curious to know about it in the comments below. On a related note I thought I should end this post with this quite amusing quote from Jerome Jerome’s book Three Men on the Bummel, published in 1900:

“In the course of the century, I am inclined to think that Germany will solve her difficulty in this respect by speaking English. Every boy and girl in Germany, above the peasant class, speaks English. Were English pronunciation less arbitrary, there is not the slightest doubt but that in the course of a very few years, comparatively speaking, it would become the language of the world. All foreigners agree that, grammatically, it is the easiest language of any to learn. A German, comparing it with his own language, where every word in every sentence is governed by at least four distinct and separate rules, tells you that English has no grammar. A good many English people would seem to have come to the same conclusion; but they are wrong. As a matter of fact, there is an English grammar, and one of these days our schools will recognise the fact, and it will be taught to our children, penetrating maybe even into literary and journalistic circles. But at present we appear to agree with the foreigner that it is a quantity neglectable. English pronunciation is the stumbling-block to our progress. English spelling would seem to have been designed chiefly as a disguise to pronunciation. It is a clever idea, calculated to check presumption on the part of the foreigner; but for that he would learn it in a year.”

June 1, 2015 Posted by | language, Personal, Quotes/aphorisms | Leave a comment