A front-tracking immersed-boundary framework for simulating Lagrangian melting problems

In so-called Lagrangian melting problems, a solid immersed in a fluid medium is free to rotate and translate in tandem with its phase-change from solid to liquid. Such configurations may be classified as a fluid-solid interaction (FSI) problem coupled to phase-change. Our present work proposes a numerical method capable of simulating these Lagrangian melting problems and adopts a front-tracking immersed-boundary (IB) method. We use the moving least squares IB framework, a well-established method for simulating a diverse range of FSI problems [1,2] and extend this framework to accommodate melting by additionally imposing the Stefan condition at the interface. In the spirit of canonical front-tracking methods, the immersed solid is represented by a discrete triangulated mesh which is separate from the Eulerian mesh in which the governing flow equations are solved. A known requirement for these methods is the need for comparable Eulerian and Lagrangian grid spacings to stabilise interpolation and spreading operations between the two grids. For a melting object, this requirement is inevitably violated unless interventional remeshing is introduced. Our work therefore presents a novel dynamic remeshing procedure to overcome this. The remeshing is based on a gradual coarsening of the triangulated Lagrangian mesh and amounts to a negligible computational burden per timestep owing to the incremental and local nature of its operations, making it a scalable approach. Moreover, the coarsening is coupled to a volume-conserving smoothing procedure detailed by Kuprat et al. [3], ensuring a zero net volume change in the remeshing step to machine precision. This added feature makes our present method highly specialised to the study of melting problems, where precise measurements of the melting solid's volume is often the primary predictive quantity of interest.</p

A Novel HPLC Method for the Concurrent Analysis and Quantitation of Seven Water-Soluble Vitamins in Biological Fluids (Plasma and Urine): A Validation Study and Application

An HPLC method was developed and validated for the concurrent detection and quantitation of seven water-soluble vitamins (C, B1, B2, B5, B6, B9, B12) in biological matrices (plasma and urine). Separation was achieved at 30°C on a reversed-phase C18-A column using combined isocratic and linear gradient elution with a mobile phase consisting of 0.01% TFA aqueous and 100% methanol. Total run time was 35 minutes. Detection was performed with diode array set at 280 nm. Each vitamin was quantitatively determined at its maximum wavelength. Spectral comparison was used for peak identification in real samples (24 plasma and urine samples from abstinent alcohol-dependent males). Interday and intraday precision were <4% and <7%, respectively, for all vitamins. Recovery percentages ranged from 93% to 100%

The effect of caffeine on cognitive performance is influenced by CYP1A2 but not ADORA2A genotype, yet neither genotype affects exercise performance in healthy adults

Purpose: To determine the influence of two commonly occurring genetic polymorphisms on exercise, cognitive performance, and caffeine metabolism, after caffeine ingestion. Methods: Eighteen adults received caffeine or placebo (3 mg kg−1) in a randomised crossover study, with measures of endurance exercise (15-min cycling time trial; 70-min post-supplementation) and cognitive performance (psychomotor vigilance test; PVT; pre, 50 and 95-min post-supplementation). Serum caffeine and paraxanthine were measured (pre, 30 and 120-min post-supplementation), and polymorphisms in ADORA2A (rs5751876) and CYP1A2 (rs762551) genes analysed.Results: Caffeine enhanced exercise performance (P  0.05). Caffeine enhanced PVT performance (P  0.05). Serum caffeine and paraxanthine responses were not different between genotypes (P > 0.05).Conclusion: Caffeine enhanced CYP1A2 ‘fast’ metabolisers’ cognitive performance more than ‘slow’ metabolisers. No other between-genotype differences emerged for the effect of caffeine on exercise or cognitive performance, or metabolism

Migration, Dispersal, and Gene Flow of Harvested Aquatic Species in the Canadian Arctic

Migration occurs when key aspects of the life cycle such as growth, reproduction, or maintenance cannot all be completed in one location. The Arctic habitats are variable and Arctic species are often migratory. The predictable nature of migrations in both space and time allow Arctic people to harvest fishes and marine mammals. We describe migratory/dispersal behavior in four types of taxa from the Canadian Arctic: anadromous and freshwater fishes, marine fishes, marine invertebrates, and marine mammals. Patterns of migration are remarkably different between these groups, in particular between distances migrated, seasonal timing of migrations, and the degree of reproductive isolation. Migratory anadromous and freshwater fishes become adapted to specific locations resulting in complex life histories and intra- and inter-population variation. Marine mammals not only migrate longer distances but also appear to have distinct demographic populations over large scales. Marine fishes tend to be panmictic, probably due to the absence of barriers that would restrict gene flow. Migratory patterns also reflect feeding or rearing areas and/or winter refugia. Migratory patterns of harvested aquatic organisms in the Canadian north are extremely variable and have shaped the north in terms of harvest, communities, and culture

Upcycling of waste cherries produces an anthocyanin-rich powder that protects against amyloid-β toxicity in C. elegans

Agricultural waste poses significant environmental and economic challenges, with the UK generating 135,000 tonnes annually. Upcycling plant-derived waste offers a sustainable approach to enhancing agricultural productivity while producing innovative, health-promoting foods. Cherries, particularly rich in anthocyanins and quercetin, possess antioxidant and anti-inflammatory properties linked to numerous health benefits. In this study researchers and a small agricultural business in Kent, the UK’s largest cherry-producing region, collaborated to quantify the bioactive compounds in products derived from waste cherries and evaluate their health potential. We find that cherry juice, pulp, and pomace retain high anthocyanin content, particularly Cyanidin-3-O-rutinoside, and contain quercetin. Using Caenorhabditis elegans as a model, we demonstrate that cherry pulp supplementation is protective in an Alzheimer’s disease model. Our study highlights the potential to upcycle agricultural waste to produce foods with health benefits while reducing waste

Trauma-Related Mortality among Adults in Rural Western Kenya: Characterising Deaths Using Data from a Health and Demographic Surveillance System

BackgroundInformation on trauma-related deaths in low and middle income countries is limited but needed to target public health interventions. Data from a health and demographic surveillance system (HDSS) were examined to characterise such deaths in rural western Kenya.Methods And FindingsVerbal autopsy data were analysed. Of 11,147 adult deaths between 2003 and 2008, 447 (4%) were attributed to trauma; 71% of these were in males. Trauma contributed 17% of all deaths in males 15 to 24 years; on a population basis mortality rates were greatest in persons over 65 years. Intentional causes accounted for a higher proportion of male than female deaths (RR 2.04, 1.37-3.04) and a higher proportion of deaths of those aged 15 to 65 than older people. Main causes in males were assaults (n=79, 25%) and road traffic injuries (n=47, 15%); and falls for females (n=17, 13%). A significantly greater proportion of deaths from poisoning (RR 5.0, 2.7-9.4) and assault (RR 1.8, 1.2-2.6) occurred among regular consumers of alcohol than among non-regular drinkers. In multivariate analysis, males had a 4-fold higher risk of death from trauma than females (Adjusted Relative Risk; ARR 4.0; 95% CI 1.7-9.4); risk of a trauma death rose with age, with the elderly at 7-fold higher risk (ARR 7.3, 1.1-49.2). Absence of care was the strongest predictor of trauma death (ARR 12.2, 9.4-15.8). Trauma-related deaths were higher among regular alcohol drinkers (ARR 1.5, 1.1-1.9) compared with non-regular drinkers.ConclusionsWhile trauma accounts for a small proportion of deaths in this rural area with a high prevalence of HIV, TB and malaria, preventive interventions such as improved road safety, home safety strategies for the elderly, and curbing harmful use of alcohol, are available and could help diminish this burden. Improvements in systems to record underlying causes of death from trauma are required

Modification of bacterial microcompartments with target biomolecules via post-translational SpyTagging

Bacterial microcompartments (BMCs) are proteinaceous organelle-like structures formed within bacteria, often encapsulating enzymes and cellular processes, in particular, allowing toxic intermediates to be shielded from the general cellular environment. Outside of their biological role they are of interest, through surface modification, as potential drug carriers and polyvalent antigen display scaffolds. Here we use a post-translational modification approach, using copper free click chemistry, to attach a SpyTag to a target protein molecule for attachment to a specific SpyCatcher modified BMC shell protein. We demonstrate that a post-translationally SpyTagged material can react with a SpyCatcher modified BMC and show its presence on the surface of BMCs, enabling future investigation of these structures as polyvalent antigen display scaffolds for vaccine development. This post-translational ‘click’ methodology overcomes the necessity to genetically encode the SpyTag, avoids any potential reduction in expression yield and expands the scope of SpyTag/SpyCatcher vaccine scaffolds to form peptide epitope vaccines and small molecule delivery agents

Gonadal Transcriptome Alterations in Response to Dietary Energy Intake: Sensing the Reproductive Environment

Reproductive capacity and nutritional input are tightly linked and animals' specific responses to alterations in their physical environment and food availability are crucial to ensuring sustainability of that species. We have assessed how alterations in dietary energy intake (both reductions and excess), as well as in food availability, via intermittent fasting (IF), affect the gonadal transcriptome of both male and female rats. Starting at four months of age, male and female rats were subjected to a 20% or 40% caloric restriction (CR) dietary regime, every other day feeding (IF) or a high fat-high glucose (HFG) diet for six months. The transcriptional activity of the gonadal response to these variations in dietary energy intake was assessed at the individual gene level as well as at the parametric functional level. At the individual gene level, the females showed a higher degree of coherency in gonadal gene alterations to CR than the males. The gonadal transcriptional and hormonal response to IF was also significantly different between the male and female rats. The number of genes significantly regulated by IF in male animals was almost 5 times greater than in the females. These IF males also showed the highest testosterone to estrogen ratio in their plasma. Our data show that at the level of gonadal gene responses, the male rats on the IF regime adapt to their environment in a manner that is expected to increase the probability of eventual fertilization of females that the males predict are likely to be sub-fertile due to their perception of a food deficient environment

PaLM 2 Technical Report

We introduce PaLM 2, a new state-of-the-art language model that has better multilingual and reasoning capabilities and is more compute-efficient than its predecessor PaLM. PaLM 2 is a Transformer-based model trained using a mixture of objectives. Through extensive evaluations on English and multilingual language, and reasoning tasks, we demonstrate that PaLM 2 has significantly improved quality on downstream tasks across different model sizes, while simultaneously exhibiting faster and more efficient inference compared to PaLM. This improved efficiency enables broader deployment while also allowing the model to respond faster, for a more natural pace of interaction. PaLM 2 demonstrates robust reasoning capabilities exemplified by large improvements over PaLM on BIG-Bench and other reasoning tasks. PaLM 2 exhibits stable performance on a suite of responsible AI evaluations, and enables inference-time control over toxicity without additional overhead or impact on other capabilities. Overall, PaLM 2 achieves state-of-the-art performance across a diverse set of tasks and capabilities. When discussing the PaLM 2 family, it is important to distinguish between pre-trained models (of various sizes), fine-tuned variants of these models, and the user-facing products that use these models. In particular, user-facing products typically include additional pre- and post-processing steps. Additionally, the underlying models may evolve over time. Therefore, one should not expect the performance of user-facing products to exactly match the results reported in this report