Electrophoretic study of enzymes from cereal aphid populations

Summary A study of variation in three peptidases (PEP–3 to –5) in a parthenogenetic S. avenae field population at Rothamsted using serial one-dimensional polyacrylamide gel electrophoresis (involving changes of gel concentration and electrophoretic run-time) increased the overall number of allozymes (mobility variants) detected from 10 under standard conditions (6% gels, 2 h run-time) to 22, as well as revealing putative heterozygous banding patterns under some test conditions. However, an examination of another enzyme, 6-phosphogluconate dehydrogenase (6-PGD) in a sample collected at Rothamsted the following year failed, using a combination of serial methods (changes of gel concentration) and isoelectric focusing, to increase the total number of 6-PGD bands separated (seven, none of which appeared to be allelic in origin). Nevertheless, some major bands were split into several bands, whilst other infrequent bands were either gained or lost. The findings are briefly discussed.     

NGF: not just for neurons.

Nerve growth factor (NFF) is the prototypic member of a family of related neurotrophins (Nts). Although originally defined by its actions in the peripheral and central nervous systems, recent data indicate the presence of extensive interactions between NGF and the endocrine and immune systems steroid hormones are able to modulate the neurosomal expression of NGF, while functional NGF receptors have been detected on cells of the immune system, and increased levels of NGF protein are found during the acute phase of diseases with a significant inflammatory component. These wider functions are likely to be of concern in any attempted therapeutic use of NGF.     

Social networks in the Little Scrub Island ground lizard (<Emphasis Type="Italic">Ameiva corax</Emphasis>)

Ameiva corax is a diurnal, widely foraging lizard endemic to a small (<2 ha) Caribbean island and is known for social foraging, whereby individuals aggregate at large food items (e.g., bird eggs and cactus fruits). We characterized the social network for A. corax through focal observations and surveys, which delineated associations for 82 known individuals. Lizards varied greatly in the extent to which they were linked to the social network. Approximately 31 % of individuals were not observed in any associations while one individual associated with 22 % (n = 18) of the animals in the study area. Larger lizards tended to be more central to the social network; body size was positively correlated with number of associations (degree) and centrality (betweenness), but negatively correlated with average distance between an individual and its associates (mean path length). Larger individuals were also associated with lower clustering coefficients, indicating that their associates were less closely interconnected. Sex was not related to number of associations (degree), but did help explain some patterns. The extent to which a lizard’s associates were of the same sex (homophily) was related to both sex and body size. Females had lower homophily scores than males; within each sex larger lizards tended to have lower homophily.     

Exploring African lion (<Emphasis Type="Italic">Panthera leo</Emphasis>) behavioural phenotypes: individual differences and correlations between sociality,boldness and behaviour

Increasing our understanding of personality, at an individual and group level, is crucial to the pre-release assessment of social species within ex situ reintroduction programs. We conducted the first exploration into the personality of a captive-origin pride of African lions (Panthera leo), assessing behavioural variations and consistencies in daily activity, social and hunting behaviour, and boldness. Data were collected via direct observations, while a species-specific protocol for testing boldness, using playbacks, was developed. Differences in sex, age and session time for the activity budget were evaluated using Pearson correlations and repeated-measures ANOVA, while social interactions were analysed using social network analysis. Spearman’s correlations were conducted to assess for associations between boldness scores, activity and sociality. The two boldness tests provided a range of scores per lion, indicating that the test was effective. Correlations and variations in individual behaviour indicated that adults and sub-adults have specific roles within pride behaviour. Correlations between boldness and activity and social behaviours provided information on the role of individuals, allowing investigation into the behaviour of a dominant and a social keystone. Our study indicates that evaluating various aspects of behaviour in conjunction with boldness has the potential to assist the pre-release assessment of a pride within an ex situ reintroduction program.     

Vertical community patterns of Labyrinthulomycetes protists reveal their potential importance in the oceanic biological pump

The biological pump plays a vital role in exporting organic particles into the deep ocean for long-term carbon sequestration. However, much remains unknown about some of its key microbial players. In this study, Labyrinthulomycetes protists (LP) were used to understand the significance of heterotrophic microeukaryotes in the transport of particulate organic matter from the surface to the dark ocean. Unlike the sharp vertical decrease of prokaryotic biomass, the LP biomass only slightly decreased with depth and eventually exceeded prokaryotic biomass in the bathypelagic layer. Sequencing identified high diversity of the LP communities with a dominance of Aplanochytrium at all depths. Notably, ASVs that were observed in the surface layer comprised ~20% of ASVs and ~60% of sequences in each of the deeper (including bathypelagic) layers, suggesting potential vertical export of the LP populations to the deep ocean. Further analyses of the vertical patterns of the 50 most abundant ASVs revealed niche partitioning of LP phylotypes in the pelagic ocean, including those that could decompose organic detritus and/or facilitate the formation of fast-sinking particles. Overall, this study presents several lines of evidence that the LP can be an important component of the biological pump through their multiple ecotypes in the pelagic ocean.     

Benzimidazole-based DGAT1 inhibitors with a [3.1.0] bicyclohexane carboxylic acid moiety

Previously disclosed benzimidazole-based DGAT1 inhibitors containing a cyclohexane carboxylic acid moiety suffer from isomerization at the alpha position of the carboxylic acid group, generating active metabolites which exhibit DGAT1 inhibition comparable to the corresponding parent compounds. In this report, we describe the design, synthesis and profiling of benzimidazole-based DGAT1 inhibitors with a [3.1.0] bicyclohexane carboxylic acid moiety. Our results show that single isomer 3A maintains in vitro and in vivo inhibition against DGAT1. In contrast to previous lead compounds, 3A does not undergo isomerization during in vitro hepatocyte incubation study or in vivo mouse study.     

Professional uncertainty and disempowerment responding to ethnic diversity in health care: a qualitative study

Background

While ethnic disparities in health and health care are increasing, evidence on how to enhance quality of care and reduce inequalities remains limited. Despite growth in the scope and application of guidelines on “cultural competence,” remarkably little is known about how practising health professionals experience and perceive their work with patients from diverse ethnic communities. Using cancer care as a clinical context, we aimed to explore this with a range of health professionals to inform interventions to enhance quality of care.

Methods and Findings

We conducted a qualitative study involving 18 focus groups with a purposeful sample of 106 health professionals of differing disciplines, in primary and secondary care settings, working with patient populations of varying ethnic diversity in the Midlands of the UK. Data were analysed by constant comparison and we undertook processes for validation of analysis. We found that, as they sought to offer appropriate care, health professionals wrestled with considerable uncertainty and apprehension in responding to the needs of patients of ethnicities different from their own. They emphasised their perceived ignorance about cultural difference and were anxious about being culturally inappropriate, causing affront, or appearing discriminatory or racist. Professionals'' ability to think and act flexibly or creatively faltered. Although trying to do their best, professionals'' uncertainty was disempowering, creating a disabling hesitancy and inertia in their practice. Most professionals sought and applied a knowledge-based cultural expertise approach to patients, though some identified the risk of engendering stereotypical expectations of patients. Professionals'' uncertainty and disempowerment had the potential to perpetuate each other, to the detriment of patient care.

Conclusions

This study suggests potential mechanisms by which health professionals may inadvertently contribute to ethnic disparities in health care. It identifies critical opportunities to empower health professionals to respond more effectively. Interventions should help professionals acknowledge their uncertainty and its potential to create inertia in their practice. A shift away from a cultural expertise model toward a greater focus on each patient as an individual may help.     

The relationship between relative weight and school attendance among elementary schoolchildren

Objective: To determine the relationship between relative weight and school attendance among elementary schoolchildren. Research Methods and Procedures: A total of 1069 fourth to sixth graders from nine elementary schools in the inner city of Philadelphia, PA, were part of an ongoing randomized control trial to assess prevention strategies for obesity. The mean rate of students eligible for free/reduced meals was 82.9 ± 11.5%. Weight was measured in the second semester of the academic year. Absentee data for the entire academic year were recorded by homeroom teachers. Participants were classified into relative weight categories described by the Institute of Medicine: underweight, normal‐weight, overweight, and obese. Results: ANOVA showed that overweight children were absent significantly more than normal‐weight children (12.2 ± 11.7 days vs.10.1 ± 10.5 days) (p < 0.05). Linear regression showed that the obese category remained a significant contributor to the number of days absent even after adjusting for age, race/ethnicity, and gender. Discussion: These data suggest that in addition to the medical and psychosocial consequences of being overweight, heavier children have greater risk for school absenteeism than their normal‐weight peers. As the rate of childhood obesity increases, parallel increases in school absenteeism should be expected.     

An additional human chromosome 21 causes suppression of neural fate of pluripotent mouse embryonic stem cells in a teratoma model

Background

Down syndrome (DS), caused by trisomy of human chromosome 21 (HSA21), is the most common genetic cause of mental retardation in humans. Among complex phenotypes, it displays a number of neural pathologies including smaller brain size, reduced numbers of neurons, reduced dendritic spine density and plasticity, and early Alzheimer-like neurodegeneration. Mouse models for DS show behavioural and cognitive defects, synaptic plasticity defects, and reduced hippocampal and cerebellar neuron numbers. Early postnatal development of both human and mouse-model DS shows the reduced capability of neuronal precursor cells to generate neurons. The exact molecular cause of this reduction, and the role played by increased dosage of individual HSA21 genes, remain unknown.

Results

We have subcutaneously injected mouse pluripotent ES cells containing a single freely segregating supernumerary human chromosome 21 (HSA21) into syngeneic mice, to generate transchromosomic teratomas. Transchromosomic cells and parental control cells were injected into opposite flanks of thirty mice in three independent experiments. Tumours were grown for 30 days, a time-span equivalent to combined intra-uterine, and early post-natal mouse development. When paired teratomas from the same animals were compared, transchromosomic tumours showed a three-fold lower percentage of neuroectodermal tissue, as well as significantly reduced mRNA levels for neuron specific (Tubb3) and glia specific (Gfap) genes, relative to euploid controls. Two thirds of transchromosomic tumours also showed a lack of PCR amplification with multiple primers specific for HSA21, which were present in the ES cells at the point of injection, thus restricting a commonly retained trisomy to less than a third of HSA21 genes.

Conclusion

We demonstrate that a supernumerary chromosome 21 causes Inhibition of Neuroectodermal DIfferentiation (INDI) of pluripotent ES cells. The data suggest that trisomy of less than a third of HSA21 genes, in two chromosomal regions, might be sufficient to cause this effect.