Dihedral Quintic Fields with a Power Basis

It is shown that there exist infinitely many dihedral quintic fields with a power basis.</p

Metabolic Processes Preserved as Biosignatures in Iron-Oxidizing Microorganisms: Implications for Biosignature Detection on Mars

Iron-oxidizing bacteria occupy a distinct environmental niche. These chemolithoautotrophic organisms require very little oxygen (when neutrophilic) or outcompete oxygen for access to Fe(II) (when acidophilic). The utilization of Fe(II) as an electron donor makes them strong analog organisms for any potential life that could be found on Mars. Despite their importance to the elucidation of early life on, and potentially beyond, Earth, many details of their metabolism remain unknown. By using on-line thermochemolysis and gas chromatography?mass spectrometry (GC-MS), a distinct signal for a low-molecular-weight molecule was discovered in multiple iron-oxidizing isolates as well as several iron-dominated environmental samples, from freshwater and marine environments and in both modern and older iron rock samples. This GC-MS signal was neither detected in organisms that did not use Fe(II) as an electron donor nor present in iron mats in which organic carbon was destroyed by heating. Mass spectral analysis indicates that the molecule bears the hallmarks of a pterin-bearing molecule. Genomic analysis has previously identified a molybdopterin that could be part of the electron transport chain in a number of lithotrophic iron-oxidizing bacteria, suggesting one possible source for this signal is the pterin component of this protein. The rock samples indicate the possibility that the molecule can be preserved within lithified sedimentary rocks. The specificity of the signal to organisms requiring iron in their metabolism makes this a novel biosignature with which to investigate both the evolution of life on ancient Earth and potential life on Mars

The effectiveness of heat preparation and alleviation strategies for cognitive performance: A systematic review

A range of occupational and performance contexts (e.g. military personnel operations, emergency services, sport) require the critical maintenance of cognitive performance in environmentally challenging environments. Several reviews exist which evaluate the effectiveness of heat preparation strategies to facilitate physical performance. To date, no review has explored the usefulness of heat preparation strategies for cognitive performance. Therefore, this systematic review aimed to evaluate a range of interventions for the maintenance of cognitive performance, during or following active or passive heat exposure. Studies to be included were assessed by two authors reviewing title, abstract, and full-text. Forty articles were identified which met the inclusion criteria. Interventions were categorised into chronic (i.e. acclimation/acclimatisation) and acute strategies (i.e. hydration, cooling, supplementation, psychological). The results indicate that medium-term consecutive heat acclimation may mitigate some cognitive deficits under heat stress, although heat acclimation effectiveness could be influenced by age. Further, pre-cooling appears the most effective cooling method for maintaining cognitive performance under heat stress, although results were somewhat ambiguous. The hydration literature showed that the most effective hydration strategies were those which individualised electrolyte fortified fluid volumes to match for sweat loss. Limited research exploring psychological interventions indicates that motivational self-talk could be facilitative for maintaining cognitive skills following exercise in hot conditions. These findings can be used to help inform strategies for maintaining critical cognitive and decision-making skills in hot environments

Visualization Techniques for Transforming Qualitative Data

Although procedures for coding raw data qualitatively are well known, ways in which these results are processed and transformed from case to case to create themes, theories, conceptual maps, and models remain obscure. To address this gap we present how we use sketch books, extraction and display tables, and Microsoft Word SmartArt to visualize relationships between qualitative concepts, categories, and variables helping us manage qualitative data analysis separation and connection recursively

Novel DNA methylation profiles associated with key gene regulation and transcription pathways in blood and placenta of growth-restricted neonates

BB/H012494/1/ Biotechnology and Biological Sciences Research Counci

Neuroprotective efficacy of P7C3 compounds in primate hippocampus.

There is a critical need for translating basic science discoveries into new therapeutics for patients suffering from difficult to treat neuropsychiatric and neurodegenerative conditions. Previously, a target-agnostic in vivo screen in mice identified P7C3 aminopropyl carbazole as capable of enhancing the net magnitude of postnatal neurogenesis by protecting young neurons from death. Subsequently, neuroprotective efficacy of P7C3 compounds in a broad spectrum of preclinical rodent models has also been observed. An important next step in translating this work to patients is to determine whether P7C3 compounds exhibit similar efficacy in primates. Adult male rhesus monkeys received daily oral P7C3-A20 or vehicle for 38 weeks. During weeks 2-11, monkeys received weekly injection of 5'-bromo-2-deoxyuridine (BrdU) to label newborn cells, the majority of which would normally die over the following 27 weeks. BrdU+ cells were quantified using unbiased stereology. Separately in mice, the proneurogenic efficacy of P7C3-A20 was compared to that of NSI-189, a proneurogenic drug currently in clinical trials for patients with major depression. Orally-administered P7C3-A20 provided sustained plasma exposure, was well-tolerated, and elevated the survival of hippocampal BrdU+ cells in nonhuman primates without adverse central or peripheral tissue effects. In mice, NSI-189 was shown to be pro-proliferative, and P7C3-A20 elevated the net magnitude of hippocampal neurogenesis to a greater degree than NSI-189 through its distinct mechanism of promoting neuronal survival. This pilot study provides evidence that P7C3-A20 safely protects neurons in nonhuman primates, suggesting that the neuroprotective efficacy of P7C3 compounds is likely to translate to humans as well

Towards Geographic Inclusion in the Evaluation of Text-to-Image Models

Rapid progress in text-to-image generative models coupled with their deployment for visual content creation has magnified the importance of thoroughly evaluating their performance and identifying potential biases. In pursuit of models that generate images that are realistic, diverse, visually appealing, and consistent with the given prompt, researchers and practitioners often turn to automated metrics to facilitate scalable and cost-effective performance profiling. However, commonly-used metrics often fail to account for the full diversity of human preference; often even in-depth human evaluations face challenges with subjectivity, especially as interpretations of evaluation criteria vary across regions and cultures. In this work, we conduct a large, cross-cultural study to study how much annotators in Africa, Europe, and Southeast Asia vary in their perception of geographic representation, visual appeal, and consistency in real and generated images from state-of-the art public APIs. We collect over 65,000 image annotations and 20 survey responses. We contrast human annotations with common automated metrics, finding that human preferences vary notably across geographic location and that current metrics do not fully account for this diversity. For example, annotators in different locations often disagree on whether exaggerated, stereotypical depictions of a region are considered geographically representative. In addition, the utility of automatic evaluations is dependent on assumptions about their set-up, such as the alignment of feature extractors with human perception of object similarity or the definition of "appeal" captured in reference datasets used to ground evaluations. We recommend steps for improved automatic and human evaluations

Environmental exposure to polychlorinated biphenyls and p,p\u27-DDE and sperm sex-chromosome disomy

Background: Chromosomal abnormalities contribute substantially to reproductive problems, but the role of environmental risk factors has received little attention. Objectives: We evaluated the association of polychlorinated biphenyl (PCB) and dichlorodiphenyldichloroethylene (p,p´-DDE) exposures with sperm sex-chromosome disomy. Methods: We conducted a cross-sectional study of 192 men from subfertile couples. We used multiprobe fluorescence in situ hybridization (FISH) for chromosomes X, Y, and 18 to determine XX, YY, XY, and total sex-chromosome disomy in sperm nuclei. Serum was analyzed for concentrations of 57 PCB congeners and p,p´-DDE. Poisson regression models were used to calculate incidence rate ratios (IRRs) for disomy by exposure quartiles, controlling for demographic characteristics and semen parameters. Results: The median percent disomy was 0.3 for XX and YY, 0.9 for XY, and 1.6 for total sex-chromosome disomy. We observed a significant trend of increasing IRRs for increasing quartiles of p,p´-DDE in XX, XY, and total sex-chromosome disomy, and a significant trend of increasing IRRs for increasing quartiles of PCBs for XY and total sex-chromosome disomy; however, there was a significant inverse association for XX disomy. Conclusions: Our findings suggest that exposure to p,p´-DDE may be associated with increased rates of XX, XY, and total sex-chromosome disomy, whereas exposure to PCBs may be associated with increased rates of YY, XY, and total sex-chromosome disomy. In addition, we observed an inverse association between increased exposure to PCBs and XX disomy. Further work is needed to confirm these findings