Reduction of trimethylamine N-oxide to trimethylamine by the human gut microbiota: supporting evidence for ‘metabolic retroversion’

Dietary sources of methylamines such as choline, trimethylamine (TMA), trimethylamine N-oxide (TMAO), phosphatidylcholine (PC) and carnitine are present in a number of foodstuffs, including meat, fish, nuts and eggs. It is recognized that the gut microbiota is able to convert choline to TMA in a fermentation-like process. Similarly, PC and carnitine are converted to TMA by the gut microbiota. It has been suggested that TMAO is subject to ‘metabolic retroversion’ in the gut (i.e. it is reduced to TMA by the gut microbiota, with this TMA being oxidized to produce TMAO in the liver). Sixty-six strains of human faecal and caecal bacteria were screened on solid and liquid media for their ability to utilize trimethylamine N-oxide (TMAO), with metabolites in spent media profiled by Proton Nuclear Magnetic Resonance (1H NMR) spectroscopy. Enterobacteriaceae produced mostly TMA from TMAO, with caecal/small intestinal isolates of Escherichia coli producing more TMA than their faecal counterparts. Lactic acid bacteria (enterococci, streptococci, bifidobacteria) produced increased amounts of lactate when grown in the presence of TMAO, but did not produce large amounts of TMA from TMAO. The presence of TMAO in media increased the growth rate of Enterobacteriaceae; while it did not affect the growth rate of lactic acid bacteria, TMAO increased the biomass of these bacteria. The positive influence of TMAO on Enterobacteriaceae was confirmed in anaerobic, stirred, pH-controlled batch culture fermentation systems inoculated with human faeces, where this was the only bacterial population whose growth was significantly stimulated by the presence of TMAO in the medium. We hypothesize that dietary TMAO is used as an alternative electron acceptor by the gut microbiota in the small intestine/proximal colon, and contributes to microbial population dynamics upon its utilization and retroversion to TMA, prior to absorption and secondary conversion to TMAO by hepatic flavin-containing monooxygenases. Our findings support the idea that oral TMAO supplementation is a physiologically-stable microbiota-mediated strategy to deliver TMA at the gut barrier

Understanding the Prospects and Potential for Improved Regional LIS Collaboration in the Developing World: An Empirical Study of LIS Departments in the GCC States

The purpose of the study was to generate information on the extent and types of collaboration occurring between academic LIS departments and faculty in the GCC states, and on the factors influencing this, to help inform policies and strategies designed to improve collaboration. This is a qualitative research study, based on interviews with Heads of LIS Departments in the GCC states. The researchers emailed all Heads of LIS Departments (n=8) in Universities within the GCC States to invite them to participate in an interview about their experiences of and views on collaboration with other LIS departments in the region. Of the (8) Heads of Departments, only 5 responded to the e-mail invitation and subsequently completed the interview. The qualitative research data generated from the interviews were analyzed using content analysis. The data were examined and a preliminary set of themes created, then, the data were re-examined and coded according to the preliminary themes. It was found that very little formal collaboration has taken place to date, but that Heads of Departments are well aware of the many potential benefits of collaboration, and the types of barriers that must be overcome to achieve this. The findings have theoretical significance relating to the potential role of LIS collaboration in developing regions more generally, and practical implications for the development of strategies and initiatives to improve collaboration in the Gulf region. A fourstage strategy development, planning, establishment and implementation model is proposed to underpin the program of work necessary to achieve this, which can also be applied to other developing regions

Considerations about multistep community detection

The problem and implications of community detection in networks have raised a huge attention, for its important applications in both natural and social sciences. A number of algorithms has been developed to solve this problem, addressing either speed optimization or the quality of the partitions calculated. In this paper we propose a multi-step procedure bridging the fastest, but less accurate algorithms (coarse clustering), with the slowest, most effective ones (refinement). By adopting heuristic ranking of the nodes, and classifying a fraction of them as `critical', a refinement step can be restricted to this subset of the network, thus saving computational time. Preliminary numerical results are discussed, showing improvement of the final partition.Comment: 12 page

Distribution Of Demersal Fishes Of The Caribbean Sea Found Below 2,000 Meters

Abyssal fishes of the Caribbean Sea are known from the work of six research vessels, yet only one ofthese collections has been reported. The most recent collection, that of the USNS BARTLETTin 1981, contains 13 new records of rare fish to the Caribbean, including two undescribed species. Twelve species accounts are given, documenting the new finds, along with some taxonomic changes from previous reports. Zoogeographical analysis revealed that the abyssal fish fauna of the Caribbean basins reflects a depauperate, tropical, western Atlantic subunit of a broader, circumglobal pattern of the world\u27s abyssal fish fauna

Hidden correlation between absorption peaks in achiral carbon nanotubes and nanoribbons

This is the final version. Available on open access from Elsevier via the DOI in this recordIn this paper we study the effect of absorption peak correlation in finite length carbon nanotubes and graphene nanoribbons. It is shown, in the orthogonal {\pi}-orbital tight-binding model with the nearest neighbor approximation, that if the ribbon width is a half of the tube circumference the effect takes place for all achiral ribbons (zigzag, armchair and bearded), and corresponding tubes, starting from lengths of about 30 nm. This correlation should be useful in designing nanoribbon-based optoelectronics devices fully integrated into a single layer of graphene.This work was supported by the EU FP7 ITN NOTEDEV (Grant No. FP7-607521), EU H2020 RISE project CoExAN (Grant No. H2020-644076), FP7 IRSES projects CANTOR (Grant No. FP7-612285), QOCaN (Grant No. FP7-316432), InterNoM (Grant No. FP7-612624); Graphene Flagship (Grant No. 604391) and partially by the Belarus state program of scientific investigations “Convergence-2020”

Correlation of ultrasound measured testicular volume with waist circumference, hip circumference, waist-hip ratio and conicity index in Nigerian adults

Background: Accurate testicular volume measurement is one way to assess testicular function. Some obese males exhibit altered levels of circulating sex steroids; decreased levels of total testosterone (T) and sex hormone binding globulin (SHBG) and increased estrogens levels. Some anthropometric measurements are markers for obesity.Objective: This study aims to evaluate the correlation of testicular volume measured by ultrasound with some anthropometric measurements: Waist circumference, Hip circumference, Waist-Hip Ratio (WHR), and Conicity Index in adult males.Methodology: One hundred and twenty-five adult male subjects comprising staff and students of a University Teaching Hospital, were recruited. The subjects' height, weight, waist circumference and hip circumference were measured and used to calculate the WHR and Conicity Index. Ultrasound measurement of the length, width and height of both testes were done and used to calculate the volumes.Results: The age of the subjects ranged from 19 to 29 years with a mean of 23.48±2.26. The mean ultrasound testicular volumes for the right and left testes were: 15.38±3.29ml and 15.29±3.89ml using the first formula; 22.86±5.43ml and 23.54±6.88ml for second formula; 21.20±5.28ml and 20.87±5.35ml for the third formula respectively. The calculated mean for height, weight, Waist circumference, Hip circumference, WHR and Conicity Index were: 174.64±6.36cm, 68.68±8.25kg, 77.51±5.44cm, 88.76±4.46cm, 0.87±0.40 and 1.14±0.05 respectively. The left, right and combined testicular volumes showed weak negative correlation with the Waist circumference, Hip circumference, WHR and Conicity Index.Conclusion: Ultrasound measured testicular volume showed weak negative correlation with the Waist circumference, Hip circumference, WHR and Conicity Index in Nigerian adults.Key words: Ultrasound, testicular volumes, waist-hip ratio, conicity index, Nigerian adult

Pregnant women’s experiences and perceptions of participating in the EVERREST prospective study; a qualitative study

Background: The EVERREST Prospective Study is a multicentre observational cohort study of pregnancies affected by severe early-onset fetal growth restriction. The study recruits women with singleton pregnancies where the estimated fetal weight is less than the 3rd centile and below 600 g, between 20 + 0 and 26 + 6 weeks of pregnancy, in the absence of a known chromosomal, structural or infective cause. Method: The reported study was retrospective descriptive qualitative interview study of women who had participated in the EVERREST Prospective Study. The aim of this study was to explore the experiences and perceptions of pregnant women taking part in research during a pregnancy affected by severe early-onset fetal growth restriction. Audio-recorded semi-structured telephone interviews were conducted with a purposive sample of 12 women, at least 1 year after delivery of their baby. Two of these pregnancies had ended in stillbirth and one in neonatal death, reflecting the outcomes seen in the EVERREST Prospective Study. Participants gave informed consent, were 16 years or older and were interviewed in English. A topic guide was used to ensure a consistent approach. Questions focused on pregnancy experiences, involvement with the EVERREST study and potential involvement in future research. Recordings were transcribed verbatim for thematic analysis using NVivo10. Results: Four broad themes were identified; ‘before joining the EVERREST Prospective Study’, ‘participating in research’, ‘information and support’ and ‘looking back and looking forwards’. Each broad theme incorporated several subthemes. All participants recalled their reaction to being told their baby was smaller than expected. The way this news was given had a lasting impact. A range of benefits of participation in the EVERREST Prospective Study were described and the participants were positive about the way it was conducted. As a consequence, they were receptive to participating in future research. However, the findings suggest that research teams should be sensitive when approaching families at a difficult time or when they are already participating in other research. Conclusions: This study highlights the willingness of pregnant women to participate in research and identifies strategies for researchers to engage participants

Galaxy And Mass Assembly (GAMA): end of survey report and data release 2

The Galaxy And Mass Assembly (GAMA) survey is one of the largest contemporary spectroscopic surveys of low redshift galaxies. Covering an area of ˜286 deg2 (split among five survey regions) down to a limiting magnitude of r < 19.8 mag, we have collected spectra and reliable redshifts for 238 000 objects using the AAOmega spectrograph on the Anglo-Australian Telescope. In addition, we have assembled imaging data from a number of independent surveys in order to generate photometry spanning the wavelength range 1 nm-1 m. Here, we report on the recently completed spectroscopic survey and present a series of diagnostics to assess its final state and the quality of the redshift data. We also describe a number of survey aspects and procedures, or updates thereof, including changes to the input catalogue, redshifting and re-redshifting, and the derivation of ultraviolet, optical and near-infrared photometry. Finally, we present the second public release of GAMA data. In this release, we provide input catalogue and targeting information, spectra, redshifts, ultraviolet, optical and near-infrared photometry, single-component Sérsic fits, stellar masses, Hα-derived star formation rates, environment information, and group properties for all galaxies with r < 19.0 mag in two of our survey regions, and for all galaxies with r < 19.4 mag in a third region (72 225 objects in total). The data base serving these data is available at http://www.gama-survey.org/

Stability-based approaches in chemoproteomics

\ua9 The Author(s), 2024. Published by Cambridge University Press. Target deconvolution can help understand how compounds exert therapeutic effects and can accelerate drug discovery by helping optimise safety and efficacy, revealing mechanisms of action, anticipate off-target effects and identifying opportunities for therapeutic expansion. Chemoproteomics, a combination of chemical biology with mass spectrometry has transformed target deconvolution. This review discusses modification-free chemoproteomic approaches that leverage the change in protein thermodynamics induced by small molecule ligand binding. Unlike modification-based methods relying on enriching specific protein targets, these approaches offer proteome-wide evaluations, driven by advancements in mass spectrometry sensitivity, increasing proteome coverage and quantitation methods. Advances in methods based on denaturation/precipitation by thermal or chemical denaturation, or by protease degradation are evaluated, emphasising the evolving landscape of chemoproteomics and its potential impact on future drug-development strategies