Anatomical variations in the branches of the human aortic arch: a recent study of a South Australian population

Variations of the branches of the aortic arch are likely to occur as a result of the altered development of certain branchial arch arteries during the embryonic period of gestation. In the present investigation the pattern of branches of the aortic arch was studied in 81 cadavers from a recent South Australian population of European descent, who have migrated to (n = 38) or were born and lived in (n = 43) South Australia during the twentieth century. Two principal variations were noted in the present study. Firstly, in 6 cadavers, the left vertebral artery originated directly from the arch of the aorta, between the left common carotid and the left subclavian arteries. The 6 subjects were among the subgroup born in South Australia, giving an incidence of 13.95%, which is much higher than in previous reports. The overall incidence of 7.41%, when related to the whole group, is also higher than incidences reported in other populations. The presence of this variation suggests that in some individuals part of the aortic arch is formed from the left 7th inter-segmental artery. Secondly, none of the cadavers examined had the thyroidea ima artery, contrasting with previously reported incidences that varied between 4% and 10%. Since all 6 cadavers with the left vertebral artery variant were born in South Australia, it is suggested that environmental factors may have contributed to this variation. Significant environmental changes in South Australia around the turn of the twentieth century are discussed. This study represents the first systematic investigation of the branches of the aortic arch in a South Australian population and provides data relevant to the practice of medicine

New perspectives on evolutionary medicine: the relevance of microevolution for human health and disease

Evolutionary medicine (EM) is a growing field focusing on the evolutionary basis of human diseases and their changes through time. To date, the majority of EM studies have used pure theories of hominin macroevolution to explain the present-day state of human health. Here, we propose a different approach by addressing more empirical and health-oriented research concerning past, current and future microevolutionary changes of human structure, functions and pathologies. Studying generation-to-generation changes of human morphology that occurred in historical times, and still occur in present-day populations under the forces of evolution, helps to explain medical conditions and warns clinicians that their current practices may influence future humans. Also, analyzing historic tissue specimens such as mummies is crucial in order to address the molecular evolution of pathogens, of the human genome, and their coadaptations.Frank Jakobus Rühli and Maciej Henneber

Two interpretations of human evolution: Essentialism and Darwinism

Despite intensive studies of a large number of fossils discovered during the 20th century there is no consensus as to the interpretation of the process of hominin evolution. Some authors see as many as six genera and some 17 species, while others argue for a single lineage from Plio/Pleistocene until today. Such diversity of interpretations of the same facts indicates lack of a uniform theoretical basis underlying studies of human evolution. Debates can be resolved using basic principles of scientific inquiry - parsimony and falsification of null hypotheses. Hypothesis testing is now possible with respect to the evolution of basic hominin characteristics such as brain size, body size and the size of the dentition that have sample sizes of a few hundred individual data points each. These characters display a continuous change with time. Analyses of variance do not falsify the null hypothesis of the existence of only one species at any time - variances around regression lines on time do not differ from the variance observed in the single species of Homo sapiens - distributions of residuals are normal. Thus, splitting of the hominin lineage into coeval species can only be based on descriptive characteristics that are liable to errors of subjective judgment.Maciej Henneber

Childhood socioeconomic position and objectively measured physical capability levels in adulthood: a systematic review and meta-analysis

<p><b>Background:</b> Grip strength, walking speed, chair rising and standing balance time are objective measures of physical capability that characterise current health and predict survival in older populations. Socioeconomic position (SEP) in childhood may influence the peak level of physical capability achieved in early adulthood, thereby affecting levels in later adulthood. We have undertaken a systematic review with meta-analyses to test the hypothesis that adverse childhood SEP is associated with lower levels of objectively measured physical capability in adulthood.</p> <p><b>Methods and Findings:</b> Relevant studies published by May 2010 were identified through literature searches using EMBASE and MEDLINE. Unpublished results were obtained from study investigators. Results were provided by all study investigators in a standard format and pooled using random-effects meta-analyses. 19 studies were included in the review. Total sample sizes in meta-analyses ranged from N = 17,215 for chair rise time to N = 1,061,855 for grip strength. Although heterogeneity was detected, there was consistent evidence in age adjusted models that lower childhood SEP was associated with modest reductions in physical capability levels in adulthood: comparing the lowest with the highest childhood SEP there was a reduction in grip strength of 0.13 standard deviations (95% CI: 0.06, 0.21), a reduction in mean walking speed of 0.07 m/s (0.05, 0.10), an increase in mean chair rise time of 6% (4%, 8%) and an odds ratio of an inability to balance for 5s of 1.26 (1.02, 1.55). Adjustment for the potential mediating factors, adult SEP and body size attenuated associations greatly. However, despite this attenuation, for walking speed and chair rise time, there was still evidence of moderate associations.</p> <p><b>Conclusions:</b> Policies targeting socioeconomic inequalities in childhood may have additional benefits in promoting the maintenance of independence in later life.</p&gt

Antibody-guided in vivo imaging of Aspergillus fumigatus lung infections during anti-fungal azole treatment

This is the final version. Available on open access from Nature Research via the DOI in this recordData availability: Due to their large size, the raw imaging data that support the findings of this study are directly available from the corresponding authors upon reasonable request. Derived data have been compiled in the Source Data file provided with this paper. Any remaining data supporting the findings from this study are available from the corresponding author upon reasonable request.Invasive pulmonary aspergillosis (IPA) is a life-threatening lung disease of immunocompromised humans, caused by the opportunistic fungal pathogen Aspergillus fumigatus. Inadequacies in current diagnostic procedures mean that early diagnosis of the disease, critical to patient survival, remains a major clinical challenge, and is leading to the empiric use of antifungal drugs and emergence of azole resistance. A non-invasive procedure that allows both unambiguous detection of IPA, and its response to azole treatment, is therefore needed. Here, we show that a humanised Aspergillus-specific monoclonal antibody, dual labelled with a radionuclide and fluorophore, can be used in immunoPET/MRI in vivo and 3D light sheet fluorescence microscopy ex vivo to quantify early A. fumigatus lung infections and to monitor the efficacy of azole therapy. Our antibody-guided approach reveals that early drug intervention is critical to prevent complete invasion of the lungs by the fungus, and demonstrates the power of molecular imaging as a non-invasive procedure for tracking IPA in vivo.Ministry of Culture and Science of North Rhine-WestphaliaGoverning Mayor of Berlin including Science and ResearchFederal Ministry of Education and ResearchEuropean Union FP7Werner Siemens Foundatio

Anomalous ion diffusion within skeletal muscle transverse tubule networks

<p>Abstract</p> <p>Background</p> <p>Skeletal muscle fibres contain transverse tubular (t-tubule) networks that allow electrical signals to rapidly propagate into the fibre. These electrical signals are generated by the transport of ions across the t-tubule membranes and this can result in significant changes in ion concentrations within the t-tubules during muscle excitation. During periods of repeated high-frequency activation of skeletal muscle the t-tubule K⁺concentration is believed to increase significantly and diffusive K⁺transport from the t-tubules into the interstitial space provides a mechanism for alleviating muscle membrane depolarization. However, the tortuous nature of the highly branched space-filling t-tubule network impedes the diffusion of material through the network. The effective diffusion coefficient for ions in the t-tubules has been measured to be approximately five times lower than in free solution, which is significantly different from existing theoretical values of the effective diffusion coefficient that range from 2–3 times lower than in free solution. To resolve this discrepancy, in this paper we study the process of diffusion within electron microscope scanned sections of the skeletal muscle t-tubule network using mathematical modelling and computer simulation techniques. Our model includes t-tubule geometry, tautness, hydrodynamic and non-planar network factors.</p> <p>Results</p> <p>Using our model we found that the t-tubule network geometry reduced the K⁺diffusion coefficient to 19–27% of its value in free solution, which is consistent with the experimentally observed value of 21% and is significantly smaller than existing theoretical values that range from 32–50%. We also found that diffusion in the t-tubules is anomalous for skeletal muscle fibres with a diameter of less than approximately 10–20 μm as a result of obstructed diffusion. We also observed that the [K⁺] within the interior of the t-tubule network during high-frequency activation is greater for fibres with a larger diameter. Smaller skeletal muscle fibres are therefore more resistant to membrane depolarization. Because the t-tubule network is anisotropic and inhomogeneous, we also found that the [K⁺] distribution generated within the network was irregular for fibres of small diameter.</p> <p>Conclusion</p> <p>Our model explains the measured effective diffusion coefficient for ions in skeletal muscle t-tubules.</p

A Cross-Cultural Comparison of Business Complaint Management Expectations

This paper is in closed access until 9th Dec 2016.Copyright © Taylor and Francis Group, LLC. This study explores the complaint management expectations of 72 British and 74 German organizational buyers using automated online means-end laddering and a Hierarchical Value Map presentation. It conceptualizes the links between expected complaint resolution attributes by the buyer (i.e., means) and the buyer's value perceptions (i.e., ends). Unlike previous research, we highlight similarities and differences in the drivers behind and attributes of complaint management expectations across two countries (Germany and the United Kingdom). Even in countries appearing to be similar economically and culturally, we find differences in the desired attributes. British buyers, for example, emphasize softer complaint resolution attributes compared to Germans. Our study is the first to present a model of complaint management expectations incorporating the role of culture, and it provides managerial directions on standardization and adaption of complaint resolution attributes. Furthermore, it evaluates justice dimensions (especially interactional justice) and their impact on perceptions of complaint management