IS SUICIDE PREVENTABLE?

Among 500 cases of suicide analyzed in Stockholm, fewer than a third were associated with depression. Most forms of psychiatric disease were represented. Nevertheless, most persons give some warning before attempting suicide, and these warnings should be the signal for preventive action. Centers with trained personnel could prevent many suicides, if the potential victims were recognized and referred early enough. Laymen too should be educated to recognize potential suicide and help avert it.     

IS IT NEUROSIS?

So-called “minor psychiatry,” the treatment of neurosis in persons who are not psychotic, may well be undertaken by the general practitioner.The first duty of the physician in dealing with a neurotic person is to determine whether psychosis may develop. He must be patient and thorough in hearing the history of the case and should have full information on the patient''s life and family.A recent classification of the neuroses is given and the more generally recognized symptoms of these conditions are described.     

IS EVOLUTIONARY BIOLOGY STRATEGIC SCIENCE?

There is a profound need for the scientific community to be better aware of the policy context in which it operates. To address this need, Evolution has established a new Outlook feature section to include papers that explore the interface between society and evolutionary biology. This first paper in the series considers the strategic relevance of evolutionary biology. Support for scientific research in general is based on governmental or institutional expenditure that is an investment, and such investment is based on strategies designed to achieve particular outcomes, such as advance in particular areas of basic science or application. The scientific community can engage in the development of scientific strategies on a variety of levels, including workshops to explicitly develop research priorities and targeted funding initiatives to help define emerging scientific areas. Better understanding and communication of the scientific achievements of evolutionary biology, emphasizing immediate and potential societal relevance, are effective counters to challenges presented by the creationist agenda. Future papers in the Outlook feature section should assist the evolutionary biology community in achieving a better collective understanding of the societal relevance of their field.     

插入序列IS2的研究：I.IS2的插入方向与极性效应

本研究利用ｆｌｉＢ,ｆｌｉＡ选择系统对ＩＳ２进行研究发现,ＩＳ２可以左、右两个方向插入某基因,插入后不仅使该该基因失去活性,而且使同一转录子内下游基因的表达受到抑制。ＩＳ２左右插入后的极性效应不同。在人工检测系统中得到的结果和自然状态的相同。     

IS THE PARTIAL MANTEL TEST INADEQUATE?

Abstract.— A publication by Raufaste and Rousset (2001) questioned the effectiveness of the partial Mantel test, a nonparametric statistical test for association among three distance matrices. By repeated simulations, we calculated the cumulative density functions of the null-hypothesis probability of no correlation, within an explicit model of causal relationships. Results do not support the criticism: in conditions of moderate correlation between the independent matrices, the actual error rate is closely associated to the intended type-I error a.     

HOW COMMON IS HOMOPLOID HYBRID SPECIATION?

Hybridization has long been considered a process that prevents divergence between species. In contrast to this historical view, an increasing number of empirical studies claim to show evidence for hybrid speciation without a ploidy change. However, the importance of hybridization as a route to speciation is poorly understood, and many claims have been made with insufficient evidence that hybridization played a role in the speciation process. We propose criteria to determine the strength of evidence for homoploid hybrid speciation. Based on an evaluation of the literature using this framework, we conclude that although hybridization appears to be common, evidence for an important role of hybridization in homoploid speciation is more circumscribed.     

WHAT DETERMINES FITNESS WHEN DISPERSAL IS LIMITED?

Simple evolutionary models typically assume a homogeneous environment in which all individuals have equal access to resources. However, when dispersal is limited this assumption is unlikely to correspond to reality. Instead, the offspring of relatively fecund parents can be expected to find that resources are scarce because of competition from their relatively large number of siblings. We show that these factors lead to selection for decreased variation in the number of offspring produced. We investigate the relationship between fitness and variation in fertility for a variety of different circumstances. Our results indicate that, in some cases, selection for reduced variation in fertility can be very substantial.     

Is the IS1 transposase, InsAB', the only IS1-encoded protein required for efficient transposition?

The transposase of the bacterial insertion sequence IS1 is normally expressed by inefficient translational frameshifting between an upstream reading frame which itself specifies a transposition inhibitor, InsA, and a second consecutive reading frame located immediately downstream. A fused-frame mutant which carries an additional base pair inserted at the point of frameshifting was constructed. This mutant exhibits high transposition activity and should express the transposase, InsAB', constitutively without frameshifting. Unexpectedly, a second protein species was observed to be expressed from this mutant. We demonstrate here that this protein, InsA*, results from continued frameshifting on the modified frameshift motif. The protein retains the activities of the repressor InsA. Its elimination, by further modification of the frameshift motif, results in a further increase in various transposition activities of IS1. These results support the hypothesis that a single IS1-encoded protein, InsAB', is necessary for transposition.     

WHAT IS THE GOOD OF HEALTH CARE?

This paper sets out to discuss what precisely is meant by 'benefit" when we talk of the requirement that the health care system concern itself with health gain or with maximizing beneficial health care. In particular I argue that in discharging the duty to do what is most beneficial we need to choose between rival conceptions of what is meant by beneficial. One is the patient's conception of benefit and the second is the provider's or funder's conception of benefit. I argue that it is the patient's conception of benefit which is paramount and that if this is followed it commits us to a conception of patient care which must be blind to prognosis in so far as prognosis is thought to bear upon issues of prioritisation or resource allocation.     

UNREQUESTED TERMINATION OF LIFE: IS IT PERMISSIBLE?

Conclusion: One can appreciate and understand why doctors take action to terminate life without being requested by the patient who is suffering unbearably and pointlessly. But in my opinion such action is not permissible from a moral point of view. In the first place there is a danger that interests other than those of the patient will play a decisive role. Furthermore, it is not permissible because the interest of society as a whole is at stake. The safety of all future patients would no longer be guaranteed. It is also not allowed because the medical profession must constantly be on its guard so that it does not become caught up in the situations described above. In nearly every case it should be possible for doctor and patient to discuss the termination of life explicitly and at an early stage. The ultimate reason why termination of life without request of the patient is not permissible is that in principle it will never be possible to draw a clear dividing line between unrequested and unwanted termination of life. However, it is conceivable that in certain cases the conflict of loyalties will be such that unrequested termination of life is justified. In the rare extreme case of an inescapable conflict of equally stringent duties, it may just be necessary to do something which in essence is impermissible.     

IS IT TIME FOR BIOETHICS TO GO EMPIRICAL?

Observers who note the increasing popularity of bioethics discussions often complain that the social sciences are poorly represented in discussions about things like abortion and stem-cell research. Critics say that bioethicists should be incorporating the methods and findings of social scientists, and should move towards making the discipline more empirically oriented. This way, critics argue, bioethics will remain relevant, and truly reflect the needs of actual people. Such recommendations ignore the diversity of viewpoints in bioethics, however. Bioethics can gain much from the methods and findings from ethnographies and similar research. But it is misleading to suggest that bioethicists are unaware of this potential benefit. Not only that, bioethicists are justified in having doubts about the utility of the social science approach in some cases. This is not because there is some inherent superiority in non-empirical approaches to moral argument. Rather, the doubts concern the nature of the facts that the sciences would provide. Perhaps the larger point is that disagreements about the relationship between facts and normative arguments should be seen as part of the normal inquiry in bioethics, not evidence that reform is needed.     

IS THE PRODUCTION OF MULTIPLE SPERM TYPES ADAPTIVE?

Males of many species concurrently produce more than one sperm type, now called sperm heteromorphism. In the Drosophila obscura group, all species examined to date produce multiple sperm types that differ in sperm length. Short sperm types in at least three obscura group species do not participate in fertilization, leading to questions regarding the adaptive value of sperm heteromorphism. The common and pervasive inheritance of this trait in the obscura group, however, may indicate that sperm heteromorphism is phylogenetically constrained and therefore does not reflect an adaptive response to selection pressures. I measured interspecific variation in sperm length and determined the number of sperm types produced in 10 obscura group species. I subsequently tested if interspecific variation in sperm length is significantly associated with phylogeny by using an autoregressive comparative method. All obscura group species examined produce two visually distinct sperm lengths, short and long. Phylogenetic autoregression analyses indicated that 22% of the interspecific variation in long sperm is related to phylogeny, whereas short sperm are not significantly correlated with phylogeny. These results suggest different selection pressures on the two sperm length types; long sperm have evolved in response to fertilization demands and short sperm have been decoupled from these requirements.     

IS SURVIVORSHIP A BETTER FITNESS SURROGATE THAN FECUNDITY?

Although fitness depends on both survivorship and fecundity, we tend to assume fecundity relates to fitness more directly than survivorship. In fact, several recent ecological studies suggest fitness depends more heavily on annual survivorship than annual fecundity for most taxa with lifespans longer than one year. These studies review elasticities of transition matrices for a broad range of taxa. Elasticities covary monotonically with selection gradients for demographic rates and are identical to selection gradients for traits rescaled to have mean values of zero and variance of one. For all taxa except semelparous perennial plants, adult survivorship has consistently higher elasticity than other suites of demographic rates. Fecundity only rarely has the highest elasticity. Thus, differences in yearly survival affect fitness disproportionately more than differences in yearly fecundity, even in many exponentially growing populations. This pattern reinforces the importance of interpreting the contribution of vital rates to fitness in the context of life history and population dynamics.