What violence prevention research can tell us about developmental psychopathology

This article reviews major issues of a developmental psychopathology understanding of youth violence and related insights gained from violence prevention efforts to date. Based in a perspective that emphasizes three areas of knowledge, epidemiology, risk factors and models, and developmental trajectories, findings are reviewed that help clarify theoretical propositions about the developmental patterns, influences, and pathways related to youth violence. Extant research is able to support several major contentions of basic developmental psychopathology theories of youth violence. Support is most robust for risk factors central to prevailing models of the development of youth violence. In addition to noting current knowledge contributions, the review suggests areas of needed additional analytic progress and theoretical extension to refine knowledge and expand understanding of the development of violence risk and its prevention.     

What sharks can tell us about the evolution of MHC genes

Summary: Similarity in structural features would argue that sharks possess class I. class IIA and class IIB genes, coding for classical peptide-presenting molecules, as well as non-classical class I genes. Some aspects of shark major histocompatibility complex genes are similar to teleost genes and others are similar to tetrapod genes. Shark class I genes form a monophyletic group, as also seen for tetrapods, but the classical and nonclassical genes form two orthologous clades, as seen for teleosts. Teleost class I genes arose independently at least four different times with the nonclassical genes of ray-finned fishes and all the shark and lobe-finned fish class I genes forming 1 clade. The ray-finned fish classical class I genes arose separately. In phylogenetic trees of class II α2 and β2 domains, the shark and tetrapod genes cluster more closely than the teleost genes and, unlike the teleost sequences, the class II α1 domains of sharks and tetrapods lack cysteines. On the other hand, both shark and teleost genes display sequence motifs in che antigen-binding cleft that have persisted over very long time periods. The similarities may reflect common selective pressures on species in aqueous environments while differences may be due to different evolutionary rates.     

What developmental disorders can tell us about the nature and origins of language

Few areas in the cognitive sciences evoke more controversy than language evolution, due in part to the difficulty in gathering relevant empirical data. The study of developmental disorders is well placed to provide important new clues, but has been hampered by a lack of consensus on the aims and interpretation of the research project. We suggest that the application of the Darwinian principle of 'descent with modification' can help to reconcile much apparently inconsistent data. We close by illustrating how systematic analyses within and between disorders, suitably informed by evolutionary theory-and ideally facilitated by the creation of an open-access database-could provide new insights into language evolution.     

What can genetics tell us about the cause of fixed airflow obstruction?

Chronic obstructive pulmonary disease (COPD) is a major cause of chronic morbidity and mortality worldwide with smoking being the most important risk factor of the disease. However, lung function and COPD are known to also have a genetic component and a deeper knowledge of the genetic architecture of the disease could lead to further understanding of predisposition to COPD and also to development of new therapeutic interventions. Genetic linkage studies and candidate gene association studies have not provided evidence to convincingly identify the genes underlying lung function or COPD. However, recent large genome‐wide association studies (GWAS) including tens of thousands of individuals have identified 26 variants at different loci in the human genome that show robust association with quantitative lung function measures in the general population. A growing number of these variants are being shown to be associated with COPD. Following the identification of these new lung function loci, the challenge now lies in refining the signals to identify the causative variants underlying the association signals and relating these signals to the molecular pathways that underlie lung function.     

Meal-interval correlations: What can they tell us?

In rats the correlation between meals and subsequent intervals is often significant, contrary to the correlation between meal size and preceding interval. From these findings it has been concluded that body weight is regulated by adjustment of intermeal interval duration rather than by adjustment of meal size. With the help of a simple qualitative model built upon notions commonly held by experimentalists in the field it is demonstrated that the above conclusion is open to two different, equally plausible interpretations—that intermeal interval is subject to (1) tighter control, or (2) stronger influence from the energy reserve, than is meal size. To check whether the facts fit the second interpretation not only the correlation coefficient, but also the variances of meals and intervals must be considered. The facts seem to confirm the “tighter control” but not the “stronger influence” view.     

What eye fixation patterns tell us about subitizing

Differences between the enumeration of very small (1-3) versus larger (4-6) numerosities were examined by investigating where people fixate when they are enumerating different numbers of items. Overall, fixations were more likely to be located in regions of the array that contained target items when the array contained 4 or more targets than when it contained 3 or fewer, a result that is consistent with previous research indicating that the enumeration of very small sets is less dependent on attentional processing than is the enumeration of larger sets. However, both the pattern of fixations across different distractor conditions and an analysis of the temporal course of fixations in the absence of distractors were inconsistent with a dichotomous distinction between pre-attentive and attentional forms of enumeration. Rather, our results suggest that, irrespective of numerosity, enumeration entails some attentional processing of target items, but attentional processing plays a markedly greater role in the enumeration of 4 or more items than in the enumeration of 3 or fewer.     

What delay fields tell us about striate cortex

It is well known that electrical activation of striate cortex (area V1) can disrupt visual behavior. Based on this knowledge, we discovered that electrical microstimulation of V1 in macaque monkeys delays saccadic eye movements when made to visual targets located in the receptive field of the stimulated neurons. This review discusses the following issues. First, the parameters that affect the delay of saccades by microstimulation of V1 are reviewed. Second, the excitability properties of the V1 elements mediating the delay are discussed. Third, the properties that determine the size and shape of the region of visual space affected by stimulation of V1 are described. This region is called a delay field. Fourth, whether the delay effect is mainly due to a disruption of the visual signal transmitted through V1 or whether it is a disturbance of the motor signal transmitted between V1 and the brain stem saccade generator is investigated. Fifth, the properties of delay fields are used to estimate the number of elements activated directly by electrical microstimulation of macaque V1. Sixth, these properties are used to make inferences about the characteristics of visual percepts induced by such stimulation. Seventh, the disruptive effects of V1 stimulation in monkeys and humans are compared. Eighth, a cortical mechanism to account for the disruptive effects of V1 stimulation is proposed. Finally, these effects are related to normal vision.     

What lysosomes actually tell us about Parkinson’s disease?

Parkinson’s disease is a common neurodegenerative disorder of unknown origin mainly characterized by the loss of neuromelanin-containing dopaminergic neurons in the substantia nigra pars compacta and the presence of intraneuronal proteinaceous inclusions called Lewy bodies. Lysosomes are dynamic organelles that degrade, in a controlled manner, cellular components delivered via the secretory, endocytic, autophagic and phagocytic membrane-trafficking pathways. Increasing amounts of evidence suggest a central role of lysosomal impairment in PD aetiology. This review provides an update on how genetic evidence support this connection and highlights how the neuropathologic and mechanistic evidence might relate to the disease process in sporadic forms of Parkinson’s disease. Finally, we discuss the influence of ageing on lysosomal impairment and PD aetiology and therapeutic strategies targeting lysosomal function.     

What can reunification of East and West Germany tell us about the cause of the allergy epidemic?

The increase of allergies in East Germany – reaching West German prevalence shortly after the reunification – is considered a model for the allergy epidemic in the western world. Whether such a pattern was observed in all comparison studies and for all allergic manifestations is not known because a complete overview is missing. Hints about possible causal factors for the allergy epidemic could be gained by identifying known risk factors, which explain the observed pattern of allergy development in Germany. Again, an overview about these efforts is missing. We identified 14 cross‐sectional studies conducted after 1989 and calculated prevalence ratios (West/East) for asthma, hayfever, eczema and allergic sensitization. Additionally, a tabular overview about the explanatory power of risk factors hypothesized in the nineties and covering outdoor exposure, indoor factors, early childhood influences, nutrition as well as awareness is given. At the time of the German reunification, the prevalence ratio West/East was largest for hayfever and sensitization to birch pollen, less pronounced for the other phenotypes and even less than one for atopic eczema. Hayfever and sensitization to birch pollen also showed the steepest increase in East Germany afterwards. Single‐room heating with fossil fuels and living as only child in a family were identified as explaining up to 23.5% of the excess trend in East compared to the trend in West. Hayfever as most typical atopic disease showed the difference in allergy pattern between East and West Germany clearest. Risk factors identified for these phenotypes are completely different (single child) or even act in the opposite direction (single‐room heating) from classical risk factors for airway diseases. This might be the most important lesson from the West/East German experience. It already stimulated many other studies focussing on protective factors such as microbial stimulation.     

Imaging volition: what the brain can tell us about the will

The question of how we can voluntarily control our behaviour dates back to the beginnings of scientific psychology. Currently, there are two empirical research disciplines tackling human volition: cognitive neuroscience and social psychology. To date, there is little interaction between the two disciplines in terms of the investigation of human volition. The aim of the current article is to highlight recent brain imaging work on human volition and to relate social psychological concepts of volition to the functional neuroanatomy of intentional action. A host of studies indicate that the medial prefrontal cortex plays a crucial role in voluntary action. Accordingly, we postulate that social psychological concepts of volition can be investigated using neuroimaging techniques, and propose that by developing a social cognitive neuroscience of human volition, we may gain a deeper understanding of this fascinating and complex aspect of the human mind.     

What birdsong can teach us about the central noradrenergic system

Increasing evidence indicates that the noradrenergic system plays a key role in biasing the nervous system towards producing behaviors that help animals adapt to constantly changing environments. Most of the studies investigating noradrenergic function are performed in animals that have a limited repertoire of tractable natural behaviors. Songbirds, in contrast, with their rich set of precisely quantifiable vocal behaviors, provide a unique model system to study the noradrenergic system. An additional advantage of this system is the existence of a well-defined neural circuit, known as the song system, that is necessary for the production, learning and perception of song and can be studied at many different levels. These include the ability to investigate the effect of norepinephrine on synaptic function using brain slices, identifying its influence on singing-related gene expression and monitoring its impact on the activity of single neurons recorded in awake behaving birds. In this review article, we describe the similarities and differences, both anatomical and functional, between the avian and mammalian noradrenergic system and its role in sensory processing, learning, attention and synaptic modulation. We also describe how the noradrenergic system influences motor production, an under-explored aspect of norepinephrine function in mammalian studies. We argue that the richness of behaviors observed in songbirds provides a unique opportunity to study the noradrenergic system in a highly integrative manner that will ultimately provide important insights into the role of this system in normal behavior and disease.     

Hyperostosis frontalis interna: What does it tell us about our health?

Objectives: To examine whether the prevalence and severity of hyperostosis frontalis interna (HFI) has significantly changed during the past 100 years. Methods: Two female populations, 100 years apart, were studied; 992 historic and 568 present day females. Detection of HFI was carried out via direct observation or CT images (Brilliance 64, Philips Medical Systems, Cleveland, Ohio). HFI was graded according to Hershkovitz et al.'s (1999) 4‐scale definition and according May et al.'s (2010c) 3‐scale definition. Results: Following correction for age, present day females manifested a significantly higher HFI prevalence compared with historic females (P < 0.05). The risk of developing HFI was found to be approximately 2.5 times greater in present day females compared with females living 100 years ago (P < 0.05). In the young age cohort, present day females manifested a significantly higher prevalence of HFI type B (P < 0.05), whereas in the old age cohort, a significant difference in the prevalence of HFI types C and D was noted between the two groups (P < 0.05). HFI tended to appear at a younger age in the present population. The last two decades has witnessed an increase in HFI prevalence (from 55.6% to 75%). Conclusions: HFI prevalence has increased during the last century, especially among young individuals, possibly indicating a profound change in human fertility patterns, together with the introduction of various hormonal treatments) and new dietary habits. Am. J. Hum. Biol., 2011. © 2011 Wiley‐Liss, Inc.     

What speech can tell us: A systematic review of dysarthria characteristics in Multiple Sclerosis

Importance

Multiple sclerosis produces neurological impairments that are variable in duration, severity and quality. Speech is frequently impaired, resulting in decreased communication skills and quality of life. Advancements in technology now makes it possible to use quantitative acoustic assessment of speech as biomarkers of disease progression.

Migrating microbes: what pathogens can tell us about population movements and human evolution

Abstract

Background: The biology of human migration can be observed from the co-evolutionary relationship with infectious diseases. While many pathogens are brief, unpleasant visitors to human bodies, others have the ability to become life-long human passengers. The story of a pathogen’s genetic code may, therefore, provide insight into the history of its human host. The evolution and distribution of disease in Africa is of particular interest, because of the deep history of human evolution in Africa, the presence of a variety of non-human primates, and tropical reservoirs of emerging infectious diseases.

Methods: This study explores which pathogens leave traces in the archaeological record, and whether there are realistic prospects that these pathogens can be recovered from sub-Saharan African archaeological contexts.

Results: Three stories are then presented of germs on a journey. The first is the story of HIV’s spread on the back of colonialism and the railway networks over the last 150?years. The second involves the spread of Schistosoma mansoni, a parasite which shares its history with the trans-Atlantic slave trade and the origins of fresh-water fishing. Finally, we discuss the tantalising hints of hominin migration and interaction found in the genome of human herpes simplex virus 2.

Conclusions: Evidence from modern African pathogen genomes can provide data on human behaviour and migration in deep time and contribute to the improvement of human quality-of-life and longevity.