Du temps perdu a la recherche

An attempt has been made to justify an academic career by outlining the approximate history of the development of ideas and tracing their origins and arborization. Because there are multifarious influences and formative factors involved in their genesis it has proved almost impossible to acknowledge all the important contributors to the patchwork of investigations that are summarized. However, whilst the review is incomplete and necessarily brief, it is hoped that a glimpse of some twentieth century preoccupations with biological science is afforded.     

Adaptability and the integration of computer-based information processing into the dynamics of organizations

The structure of a system influences its adaptability. An important result of adaptability theory is that subsystem independence increases adaptability [Conrad, M., 1983. Adaptability. Plenum Press, New York]. Adaptability is essential in systems that face an uncertain environment such as biological systems and organizations. Modern organizations are the product of human design. And so it is their structure and the effect that it has on their adaptability. In this paper we explore the potential effects of computer-based information processing on the adaptability of organizations. The integration of computer-based processes into the dynamics of the functions they support and the effect it has on subsystem independence are especially relevant to our analysis.     

Clathrin-independent endocytosis: from nonexisting to an extreme degree of complexity

Today it is generally accepted that there are several endocytic mechanisms, both the clathrin-dependent one and mechanisms which operate without clathrin and with different requirements when it comes to dynamin, small GTP-binding proteins of the Rho family and specific lipids. It should be noted that clathrin-independent endocytosis can occur even when the cholesterol level in the membrane has been reduced to so low levels that caveolae are gone and clathrin-coated membrane areas are flat. Although new investigators in the field take it for granted that there is a multitude of entry mechanisms, it has taken a long time for this to become accepted. However, more work needs to be done, because one can still ask the question: How many endocytic mechanisms does a cell have, what are their function, and how are they regulated? This article describes some of the history of endocytosis research and attempts to give an overview of the complexity of the mechanisms and their regulation.     

Sorcerers,saints and charlatans: Black folk healers in urban America

Case histories of black Americans who believe their illness has been caused by sorcery have been reported with increasing frequency in the clinical literature. Such individuals often believe that their problems are not amenable to orthodox medical regimens and they may leave treatment to seek out a folk healer. Healers believed to be able to cure sorcery are viewed ambivalently as they are thought able to magically cause illness as well as cure it. There is little information available on such individuals or their modes of treatment, making it difficult to assess their abilities. This article reviews what is known about such individuals, including an attempt to learn more about those who have advertised in a large city newspaper. It is concluded that some of these individuals provide a useful service to their clients but that many others use their reputations as manipulators of occult powers to extract money from the poor and gullible.     

Substance use and mating success

Psychoactive substance use has been typical of most traditional and modern societies and is maintained in the population despite the potential for abuse and related harms, raising the possibility that it (or its underlying causes) confers fitness benefits that offset its costs. Although it seems plausible that psychoactive substances have facilitated survival among ancestral and modern humans, it is not clear that this enhancement has translated into Darwinian fitness through mating and ultimately reproductive success. In the current study, we discuss potential mechanisms by which substance use might make unique contributions to mating success, attend to the possibility that the effects between substance use and mating success are instead confounded, and use structural equations and nationally representative data to determine whether these effects are more likely causal or spurious. Our findings indicate that once we know participants' scores on “third” variables at each round in early young adulthood, their substance use gives us little additional information about their current prospects for acquiring sexual partners and no additional information about of their future prospects. Thus, if adaptations for substance use evolved, their adaptive value does not seem to be found in mating success.     

Neurotrophins, synaptic plasticity and dementia

The growing realization that neurotrophins, such as brain-derived neurotrophic factor (BDNF), are crucial in modulating synaptic plasticity has broadened the spectrum of their trophic actions. At the same time, it has become clear that Abeta peptides derived from amyloid precursor protein (APP) have dramatic effects on synaptic transmission before the onset of the neurodegenerative disease. Because neurotrophins and Abeta are responsible for affecting both synaptic and cognitive function, it is likely that their mechanisms of action will be related and might even intersect. This review highlights several recent findings that suggest trophic factors and APP use similar pathways to control neuronal activity.     

The Truth from the Body: Medical Certificates as Ultimate Evidence for Asylum Seekers

Whether through traditional law or modern torture, the body has always been a privileged site on which to demonstrate the evidence of power. But for immigrants, the poor, and, more generally, the dominated—all of whom have to prove their eligibility to certain social rights—it has also become the place that displays the evidence of truth. In France, as immigration control increases, asylum seekers are more and more submitted to the evaluation of their physical sequels and psychic traumas, as if their autobiographical accounts were not sufficient. In this article, we show how nongovernmental organizations (NGOs) deal with the dilemmas posed by this situation, how they develop protocols standardizing their expertise, and how their medical authority progressively substitutes itself for the asylum seekers' word. In this process of objectification, it is the experience of the victims as political subjects that is progressively erased.     

Parent–Offspring Conflict in Primates

Parent–offspring conflict (POC) theory (Trivers, 1974) has stimulated controversy in evolutionary biology and behavioral ecology. The theory has been criticized by some primate behavioral researchers on both conceptual and empirical grounds. First, it has been argued that it would be more advantageous to mothers and offspring to agree over the allocation of parental investment and to cooperate rather than to disagree and engage in conflict. Second, some studies have provided data suggesting that primate mothers and offspring engage in behavioral conflict over the scheduling of their activities rather than parental investment. In reality, parent–offspring interactions are likely to involve both cooperation and conflict, and the hypothesis that mothers and infants squabble over the scheduling of their activities is not incompatible with POC theory. Furthermore, the predictions of POC theory are supported by a number of empirical studies of primates. POC theory has enhanced our understanding of the dynamics of parent–offspring relationships in many animal species, and it is very likely that future studies of primates will continue to benefit from using POC theory as an explanatory framework.     

Genome analyses and modelling the relationships between coding density, recombination rate and chromosome length

In the human genomes, recombination frequency between homologous chromosomes during meiosis is highly correlated with their physical length while it differs significantly when their coding density is considered. Furthermore, it has been observed that the recombination events are distributed unevenly along the chromosomes. We have found that many of such recombination properties can be predicted by computer simulations of population evolution based on the Monte Carlo methods. For example, these simulations have shown that the probability of acceptance of the recombination events by selection is higher at the ends of chromosomes and lower in their middle parts. The regions of high coding density are more prone to enter the strategy of haplotype complementation and to form clusters of genes, which are “recombination deserts”. The phenomenon of switching in-between the purifying selection and haplotype complementation has a phase transition character, and many relations between the effective population size, coding density, chromosome size and recombination frequency are those of the power law type.     

The molecular bases for copper uptake and distribution: lessons from yeast

Copper exists in two oxidation states, cuprous (Cu1+) and cupric (Cu2+), which, respectively, can donate or accept electrons. The fact that copper has two readily interconvertible redox states makes it a catalytic co-factor for many important enzymes. Over the past years, work in a number of laboratories has clearly demonstrated that studies in yeast have served as a springboard for identifying cellular components and processes involved in copper uptake and distribution. In several cases, it has been shown that mammalian proteins are capable of functionally replacing yeast proteins, thereby revealing their remarkable functional conservation. For high-affinity copper transport into cells, it has been shown that copper transporters of the Ctr family are required. Upon entering the cell, copper is partitioned to different proteins and into different compartments within the cell. Given the potential toxicity of copper, specialized proteins bind copper after it enters the cell and subsequently donate the bound copper to their corresponding recipient proteins. Three copper-binding proteins, Ccs1, Cox17, and Atx1, have been identified that serve as "copper chaperones" to deliver copper. double dagger.     

Tool use in wild orang-utans modifies sound production: a functionally deceptive innovation?

Culture has long been assumed to be uniquely human but recent studies, in particular on great apes, have suggested that cultures also occur in non-human primates. The most apparent cultural behaviours in great apes involve tools in the subsistence context where they are clearly functional to obtain valued food. On the other hand, tool-use to modify acoustic communication has been reported only once and its function has not been investigated. Thus, the question whether this is an adaptive behaviour remains open, even though evidence indicates that it is socially transmitted (i.e. cultural). Here we report on wild orang-utans using tools to modulate the maximum frequency of one of their sounds, the kiss squeak, emitted in distress. In this variant, orang-utans strip leaves off a twig and hold them to their mouth while producing a kiss squeak. Using leaves as a tool lowers the frequency of the call compared to a kiss squeak without leaves or with only a hand to the mouth. If the lowering of the maximum frequency functions in orang-utans as it does in other animals, two predictions follow: (i) kiss squeak frequency is related to body size and (ii) the use of leaves will occur in situations of most acute danger. Supporting these predictions, kiss squeaks without tools decreased with body size and kiss squeaks with leaves were only emitted by highly distressed individuals. Moreover, we found indications that the calls were under volitional control. This finding is significant for at least two reasons. First, although few animal species are known to deceptively lower the maximum frequency of their calls to exaggerate their perceived size to the listener (e.g. vocal tract elongation in male deer) it has never been reported that animals may use tools to achieve this, or that they are primates. Second, it shows that the orang-utan culture extends into the communicative domain, thus challenging the traditional assumption that primate calling behaviour is overall purely emotional.     

Synaptic ribbons: machines for priming vesicle release?

Synaptic ribbons are specialized organelles that hold vesicles close to the active zone of sensory synapses, but their function is mysterious. Acute disruption of the ribbon complex using light has now revealed that it has a role in priming synaptic vesicles for fusion.     

Bioethics and conflicts of interest

Bioethics has been subject to considerable social criticism in recent years. One criticism that has caused particular discomfort in the bioethics community is that bioethicists, because of the way their work is funded, are involved in profound conflicts of interest that undermine their title to be considered independent moral commentators on developments in biomedicine and biotechnology. This criticism draws its force from the assumption that bioethics is, or ought to be, a type of normative social criticism. Versions of this criticism come from both the political left and right. For instance, such criticisms include allegations that bioethics is inherently socially conservative, that it is inherently “pro-technology”, that it lays spurious claims to moral and social authority and expertise, that its focus on autonomy links it to neoliberal theories of choice, and that it is an ideological mystification of real social relationships and political power. This commentary paper analyses the problem of bioethical conflict of interest, and argues that the types of conflict of interest facing bioethics are inherent to the role of “public intellectual” that bioethicists generally wish to assume. The paper defends this conception of the role of the bioethicist, arguing that bioethicists should be interested and openly so.     

芦芽山生态旅游植被景观特征与地理因子的相关分析

自然保护区是生态旅游的好去处。植被景观不仅仅是其重要的风景,而且更是协调其生态平衡的杠杆所在。通过取样调查,采用一系列植被景观特征指标,分析了芦山旅游植被景观特征与地理因子的关系。结果表明;芦牙山旅游植被景观特征的评价几乎不受自然环境的影响,而受人为活动影响较大。相对于自然地理因子而言,人文地理因子（即旅游活动）对植被景观具有更为显著的影响。此外,阴生种比值作为植被生态环境质量评价的指标,在本研究区域具有一定的非适用性。     

How reliably do amino acid composition comparisons predict sequence similarities between proteins?

A method for comparing amino acid compositions of proteins (Cornish-Bowden, 1977) has been extended to allow proteins of unequal lengths to be compared. The method has been tested by applying it to proteins of known sequence. It tends to exaggerate the amount of difference between unrelated proteins. It is therefore a reliable guide to possible sequence similarities, in that it does not suggest that sequences are similar when they are not, though it sometimes fails to detect genuine similarities. When applied to related proteins the method gives results in good agreement with those predicted. A phylogenetic tree for 37 snake venom toxins has been constructed from their compositions and is similar in most important respects to one constructed from the corresponding sequences.     

A study of family communication space (Part I)--A preliminary study on how family communication is actually practiced

Housing science needs to concern itself with how to improve space for family communication because it plays an important role in human dwelling life. The purpose of this report (Parts I, II & III) is, hence, to elucidate various factors conditioning family communication, and spatial traits of the rooms where it is conducted, based on the survey of the households of students at women's junior colleges. Part I delves into what is specifically communicated within a family and how it is related with other living activities, by grasping how communication is practiced in everyday family life. A basic analysis is made as to how conscious a family members are of their mutual communication, and how rooms are used for it. It has become clear that family communication is closely related with meal-taking both behaviorally and spatially, and that different attitudes among a family members toward family communication cause different modes, and evaluations of it. It has proved to be necessary, for the further studies of family communication, to give an analytical perspective to an in-depth examination of how rooms in the target families are used and how every member views and evaluates their family communication.     

New perspectives on the evolution of exaggerated traits

The scaling of body parts is central to the evolution of morphology and shape. Most traits scale proportionally with each other and body size such that larger adults are essentially magnified versions of smaller ones. This pattern is so ubiquitous that departures from it – disproportionate scaling between trait and body size – pique interest because it can generate dramatically exaggerated traits. These extreme morphologies are frequently hypothesized to result from sexual selection and their study has a long history, with several hypotheses seeking to explain their evolution. Despite this effort, surprisingly little progress has been made in demonstrating the forms of selection that produce different scaling patterns or in identifying the mechanisms that underlie the expression and evolution of scaling relationships. Here we review recent insights regarding the proximate mechanisms that regulate and integrate trait growth and that offer a new framework for studying the evolution of morphological scaling.