Opening Remarks: Thinking and Deciding

SYNOPSIS. Apart from providing students with the fundamentalconcepts and some of the data supporting these concepts, anintroductory university course in biology should suggest waysof thinking about important human problems that relate to biology.Most of these problems such as abortion, genetic engineering,right to life, environmental pollution, and overuse of naturalresources, have no single solution that will be accepted byall people. Science cannot specify what the solution shouldbe—that must be a human choice. However, the data andprocedures of science can be invaluable in helping human beingsmake informed choices and, once a choice has been made, makemore probable the achieving of the desired goal.     

Defining the Structure of Irregular Nucleic Acids: Conventions and Principles

Abstract

The algorithm “Curves”, that we have recently presented in this journal (J. Biolmol. Str. Dynam. 6, 63–91 (1988)), is updated to take into account the conventions developed at the Cambridge meeting on DNA curvature (September 1988) and extended to the calculation of local parameters. In addition, the principles which govern the choices made in establishing the Curves algorithm are compared with the approaches adopted by other authors.     

Death and Rebirth: Images of Death in Sicily

Photographs were often taken during funerary ceremonies in Sicily. Local photographers were commissioned to document funerals as if they were christenings, communions or wedding ceremonies; and it is no mere coincidence that in funeral portraits the relatives arranged around the coffin assumed postures similar to those seen in photos of festivities. This tradition of taking photos during such “mixed occasions” gives the images a profound significance and highlights the archaic roots of the popular ideology of death as a continuum of life.     

Rituals of Death as a Context for Understanding Personal Property in Socialist Mongolia

This article proposes that we rethink the concept of 'personal property', and it uses the example of Mongolian rituals of death in the socialist 1980s as a context for exploring this idea. These rituals are not the occasion for dividing up property amongst inheritors (this has usually been agreed upon long before death) but involve a series of actions that specify the deceased's relations with material things. Objects become personal property through prolonged use and physical interaction. The rites are concerned with the deceased's relations with such things, focused on desire, relinquishment, dependence, and other emotions. The article thus shifts attention back to the 'person-thing' aspect of property. It also discusses the socio-political contexts in which such a relation becomes important and argues that socialist society did not eliminate but rather opened up contexts in which such personalization could occur. It is argued more generally that personal property so situated is quite different from the 'private property' that is so prominent in capitalist society. This in turn requires us to rethink the way that 'possession' may be imagined, and to consider forms of property that are conceptualized more in terms of human attachment to objects than as exclusionary relations vis-à-vis other owners. The Mongolian ethnography suggests that, just as people alter material things by long and intensive interaction with them, there are categories of personal property that also change their owners, since actions of using, giving up, donation, and so forth are ethical matters that transform the person.     

Injuries,Death, and Disability Associated with 11 Years of Conflict in Baghdad,Iraq: A Randomized Household Cluster Survey

Background

The objective of this study was to characterize injuries, deaths, and disabilities arising during 11 years of conflict in Baghdad.

Methods

Using satellite imagery and administrative population estimated size for Baghdad, 30 clusters were selected, proportionate to population size estimates. Interviews were conducted during April and May 2014 in 900 households containing 5148 persons. Details about injuries and disabilities occurring from 2003 through May 2014 and resultant disabilities were recorded.

Findings

There were 553 injuries reported by Baghdad residents, 225 of which were intentional, and 328 unintentional. For intentional injuries, the fatality rate was 39.1% and the disability rate 56.0%. Gunshots where the major cause of injury through 2006 when blasts/explosions became the most common cause and remained so through 2014. Among unintentional injuries, the fatality rate was 7.3% and the disability rate 77.1%. The major cause of unintentional injuries was falls (131) which have increased dramatically since 2008, followed by traffic related injuries (81), which have steadily increased. The proportion of injuries ending in disabilities remained fairly constant through the survey period.

Interpretation

Intentional injuries added substantially to the burden of unintentional injuries for the population. For Baghdad, the phases of the Iraqi conflict are reflected in the patterns of injuries and consequent deaths reported. The scale of injuries during conflict is most certainly under-reported. Difficulties recalling injuries in a survey covering 11 years is a limitation, but it is likely that minor injuries were under-reported more than severe injuries. The in- and out-migration of Baghdad populations likely had effects on the events reported which we could not measure or estimate. Damage to the health infrastructure and the flight of health workers may have contributed to mortality and morbidity. Civilian injuries as well as mortality should be measured during conflicts, though not currently done.     

Early Mortality and Primary Causes of Death in Mothers of Children with Intellectual Disability or Autism Spectrum Disorder: A Retrospective Cohort Study

Introduction

Mothers of children with intellectual disability or autism spectrum disorder (ASD) have poorer health than other mothers. Yet no research has explored whether this poorer health is reflected in mortality rates or whether certain causes of death are more likely. We aimed to calculate the hazard ratios for death and for the primary causes of death in mothers of children with intellectual disability or ASD compared to other mothers.

Methods

The study population comprised all mothers of live-born children in Western Australia from 1983–2005. We accessed state-wide databases which enabled us to link socio-demographic details, birth dates, diagnoses of intellectual disability or ASD in the children and dates and causes of death for all mothers who had died prior to 2011. Using Cox Regression with death by any cause and death by each of the three primary causes as the event of interest, we calculated hazard ratios for death for mothers of children intellectual disability or ASD compared to other mothers.

Results and Discussion

During the study period, mothers of children with intellectual disability or ASD had more than twice the risk of death. Mothers of children with intellectual disability were 40% more likely to die of cancer; 150% more likely to die of cardiovascular disease and nearly 200% more likely to die from misadventure than other mothers. Due to small numbers, only hazard ratios for cancer were calculated for mothers of children with ASD. These mothers were about 50% more likely to die from cancer than other mothers. Possible causes and implications of our results are discussed.

Conclusion

Similar studies, pooling data from registries elsewhere, would improve our understanding of factors increasing the mortality of mothers of children with intellectual disability or ASD. This would allow the implementation of informed services and interventions to improve these mothers'' longevity.     

Novel Loci Associated with Increased Risk of Sudden Cardiac Death in the Context of Coronary Artery Disease

Background

Recent genome-wide association studies (GWAS) have identified novel loci associated with sudden cardiac death (SCD). Despite this progress, identified DNA variants account for a relatively small portion of overall SCD risk, suggesting that additional loci contributing to SCD susceptibility await discovery. The objective of this study was to identify novel DNA variation associated with SCD in the context of coronary artery disease (CAD).

Methods and Findings

Using the MetaboChip custom array we conducted a case-control association analysis of 119,117 SNPs in 948 SCD cases (with underlying CAD) from the Oregon Sudden Unexpected Death Study (Oregon-SUDS) and 3,050 controls with CAD from the Wellcome Trust Case-Control Consortium (WTCCC). Two newly identified loci were significantly associated with increased risk of SCD after correction for multiple comparisons at: rs6730157 in the RAB3GAP1 gene on chromosome 2 (P = 4.93×10⁻¹², OR = 1.60) and rs2077316 in the ZNF365 gene on chromosome 10 (P = 3.64×10⁻⁸, OR = 2.41).

Conclusions

Our findings suggest that RAB3GAP1 and ZNF365 are relevant candidate genes for SCD and will contribute to the mechanistic understanding of SCD susceptibility.     

Deciding group movements: Where and when to go

A group of animals can only move cohesively, if group members “somehow” reach a consensus about the timing (e.g., start) and the spatial direction/destination of the collective movement. Timing and spatial decisions usually differ with respect to the continuity of their cost/benefit distribution in such a way that, in principle, compromises are much more feasible in timing decision (e.g., median preferred time) than they are in spatial decisions. The consequence is that consensus costs connected to collective timing decisions are usually less skewed amongst group members than are consensus costs connected to spatial decisions. This, in turn, influences the evolution of decision sharing: sharing in timing decisions is most likely to evolve when conflicts are high relative to group cohesion benefits, while sharing in spatial decisions is most likely to evolve in the opposite situation. We discuss the implications of these differences for the study of collective movement decisions.     

Death in the CNS: six-microns-under

During embryonic development, large numbers of apoptotic cells are rapidly cleared by phagocytes. In this issue, Kurant et al. (2008) describe a new phagocytic receptor, called six-microns-under (SIMU), that promotes engulfment of apoptotic neurons by glial cells in the developing nervous system of Drosophila.     

Deciding on the wing: in-flight decision making and search space sampling in the red dwarf honeybee Apis florea

During reproductive swarming and seasonal migration, a honeybee swarm needs to locate and move to a new, suitable nest site. While the nest-site selection process in cavity-nesting species such as the European honeybee Apis mellifera is very precise with the swarm carefully selecting a single site, open-nesting species, such as Apis florea, lack such precision. These differences in precision in the nest-site selection process are thought to arise from the differing nest-site requirements of open- and cavity-nesting species. While A. florea can nest on almost any tree, A. mellifera is constrained by the scarcity of suitable nest sites. Here we show that imprecision in the nest-site selection process allows swarms to quickly reach a decision when many nest sites are available. In contrast, a very precise nest-site selection process slows down the decision-making process when nest sites are abundant.     

Chronic Disease and Disability in the Community: A Prevalence Study

A two-stage prevalence survey of disability (defined as the inability to perform unaided defined activities essential to daily life) used questionnaires on a random sample of the population living in north Lambeth. The central estimates of the prevalence of disability in those aged 35-74 are 7·2% for men and 9·7% for women. Among the disabled population locomotor impairments were more common in women; internal impairments were more common in men. For men and women together chronic respiratory disease, mainly bronchitis, was shown to be the single most common condition associated with disability.Though for women there may be an association between low social class and disability and between marital break-up and disability, these associations, though statistically significant, are weak. The data are therefore considered to be more widely relevant for the planning of health and welfare services.     

Epigenetics and Cell Death: DNA Hypermethylation in Programmed Retinal Cell Death

Background

Vertebrate genomes undergo epigenetic reprogramming during development and disease. Emerging evidence suggests that DNA methylation plays a key role in cell fate determination in the retina. Despite extensive studies of the programmed cell death that occurs during retinal development and degeneration, little is known about how DNA methylation might regulate neuronal cell death in the retina.

Methods

The developing chicken retina and the rd1 and rhodopsin-GFP mouse models of retinal degeneration were used to investigate programmed cell death during retinal development and degeneration. Changes in DNA methylation were determined by immunohistochemistry using antibodies against 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC).

Results

Punctate patterns of hypermethylation paralleled patterns of caspase3-dependent apoptotic cell death previously reported to occur during development in the chicken retina. Degenerating rd1 mouse retinas, at time points corresponding to the peak of rod cell death, showed elevated signals for 5mC and 5hmC in photoreceptors throughout the retina, with the most intense staining observed in the peripheral retina. Hypermethylation of photoreceptors in rd1 mice was associated with TUNEL and PAR staining and appeared to be cCaspase3-independent. After peak rod degeneration, during the period of cone death, occasional hypermethylation was observed in the outer nuclear layer.

Conclusion

The finding that cell-specific increases of 5mC and 5hmC immunostaining are associated with the death of retinal neurons during both development and degeneration suggests that changes in DNA methylation may play a role in modulating gene expression during the process of retinal degeneration. During retinal development, hypermethylation of retinal neurons associates with classical caspase-dependent apoptosis as well as caspase-3 independent cell death, while hypermethylation in the rd1 mouse photoreceptors is primarily associated with caspase-3 independent programmed cell death. These findings suggest a previously unrecognized role for epigenetic mechanisms in the onset and/or progression of programed cell death in the retina.     

The Formation of Social Conventions in Real-Time Environments

Why are some behaviors governed by strong social conventions while others are not? We experimentally investigate two factors contributing to the formation of conventions in a game of impure coordination: the continuity of interaction within each round of play (simultaneous vs. real-time) and the stakes of the interaction (high vs. low differences between payoffs). To maximize efficiency and fairness in this game, players must coordinate on one of two equally advantageous equilibria. In agreement with other studies manipulating continuity of interaction, we find that players who were allowed to interact continuously within rounds achieved outcomes with greater efficiency and fairness than players who were forced to make simultaneous decisions. However, the stability of equilibria in the real-time condition varied systematically and dramatically with stakes: players converged on more stable patterns of behavior when stakes are high. To account for this result, we present a novel analysis of the dynamics of continuous interaction and signaling within rounds. We discuss this previously unconsidered interaction between within-trial and across-trial dynamics as a form of social canalization. When stakes are low in a real-time environment, players can satisfactorily coordinate ‘on the fly’, but when stakes are high there is increased pressure to establish and adhere to shared expectations that persist across rounds.     

Secure the Shadow: Death and Photography in America

Secure the Shadow: Death and Photography in America. Jay Ruby. Cambridge, MA: MIT Press, 1995. 220 pp.     

Deciding final clusters: An approach using intra- and intercluster distances

An approach for deciding final clusters of a dendrogram is provided. Whether developed by agglomerative or divisive cluster analysis, decisions start at the 2-cluster level of the dendrogram. Cluster density is viewed as compactness and, therefore, is related to interindividual distances. The two clusters and the intercluster space are seen as treatments in analysis of variance with intercluster space as the control treatment. Distances in an interindividual matrix are considered measures of response to the three treatments. The F-ratio indicates if the treatment means differ; the least significant difference indicates which ones are different. The example provided explains our approach in searching for optimal clustering levels.