Explaining Low Redshift Quasar Evolution

We have developed a flexible framework for constructing physical models of quasar evolution that can incorporate a wide variety of observational constraints, such as multi-wavelength quasar luminosity functions (QLFs), estimated masses and accretion rates of active black holes, space densities of quasar host galaxies, clustering measurements, and the mass function of black holes in the local universe. In this brief contribution we focus on the observed decline in the QLF break luminosity at $z<2$, which can be explained either by a shift toward lower characteristic accretion rates at low $z$ or by preferential suppression of activity in higher mass black holes.Comment: 2 pages, 1 figure, to be published in the Proceedings of "Multiwavelength AGN Surveys", Cozumel, Dec 8 - 12, 200

The effect of farmland abandonment on dung beetle diversity and function in the Nama-Karoo, Northern Cape, South Africa.

Thesis (MScConsEcol)--Stellenbosch University, 2020.ENGLISH ABSTRACT: Agricultural land abandonment has cascading effects on native biota. When badly managed, pressures on native biota can increase leading to reduced ecosystem function. Conversely, increased ecosystem function can result after decreasing anthropogenic pressures. This phenomenon has received little attention in the often-overexploited arid rangeland areas of the world. Here, I used a keystone taxon, dung beetles, as a bioindicator of the effect of farmland abandonment in the Nama-Karoo of South Africa. I documented changes in dung beetle abundance, richness, community assemblage composition, and their functional diversity as a result of ceasing large-scale sheep farming and evaluated differences in these factors across different biotopes. Dung beetles were sampled using baited pitfall traps on farms that were abandoned a long time ago (>10 years), recently (ca. 1 year ago) and on active farms, as well as from three dominant biotopes (hills, flatlands and ephemeral riparian zones) using three dung types (omnivore = pig; ruminant non-pelleted = cow; and ruminant pelleted = sheep). In general, riparian systems and flatlands had greater dung beetle richness, abundance, biomass and functional richness in comparison with hills, and each had a unique assemblage composition. Therefore, the flatland and ephemeral riparian areas that are generally most severely impacted by anthropogenic actions (since rocky slopes inhibit grazing activities) are particularly important for conserving dung beetle ecosystem functions and services. Dung beetle richness, abundance, and functional richness was higher in abandoned farmland areas due to greater dependence on omnivore and cow dung than on sheep dung, and reduced pressures on remaining native vertebrates. However, large-bodied dung beetles became rare after farmland abandonment. I therefore strongly encourage the reintroduction of native meso-herbivores to enhance dung resources in these abandoned areas, which will support higher dung beetle diversity, greater ecosystem function and increased ecosystem services.AFRIKAANSE OPSOMMING: Die staking van veeboerdery kan 'n effek hê op inheemse biota. Indien dit sleg bestuur kan die druk op inheemse biota toeneem tot 'n verminderde ekosisteemfunksie. Tog kan 'n verhoogde ekosisteemfunksie ontstaan na so 'n afname in antropogeniese druk. Hierdie verskynsel het min aandag geniet in die dikwels oorbenutte droë gebiede van die wêreld. Hier het ek 'n sleutelsteen takson, miskruiers, as bioindikator gebruik om die effek van landbougrondverlating in die Nama-Karoo van Suid-Afrika te bestudeer. Ek het veranderinge in die volopheid van miskruiers, spesies-rykheid, samestelling van gemeenskappe asook hul funksionele diversiteit gedokumenteer as gevolg van die staking van grootskaalse skaapboerdery en die verskille tussen hierdie faktore oor verskillende biotope geëvalueer. Ek het miskruiers gevang deur gebruik te gebruik van lokvalle op plase wat al 'n geruime tyd gelede (> 10 jaar) ontruim is, onlangs ontruim is (ongeveer 1 jaar gelede) of steeds aktief is, en dan ook in drie dominante biotope (klipkoppies/heuwels, platvlaktes en efemerale oewersones) met behulp van drie soorte mis (omnivore = vark; herkouer = koei; en nie-herkouer = skape). Oor die algemeen het oewerstelsels en platvlaktes groter miskruier rykheid, volopheid, biomassa en funksionele rykdom in vergelyking met klipperige heuwels gehad, elkeen met 'n unieke spesies samestelling. Daarom is die plat vlaktes en efemerale oewergebiede, wat meestal die ergste geraak word deur antropogeniese optrede (aangesien klipperige hellings weidingsaktiwiteite belemmer) veral belangrik vir die behoud van ekosisteemfunksies en dienste van miskruiers. Interessant genoeg was die rykheid, oorvloed en funksionele rykheid van miskewers hoër in verlate landbougebiede as gevolg van 'n groter afhanklikheid van herkouer mis as van nie-herkouer (skaap) mis, asook druk op die inheemse soogdiere wat verminder het. Die grootste miskruiers het egter skaars geword ná die verlating van landbougrond. Ek moedig die herinvoering van inheemse meso-herbivore sterk aan om mis kwaliteit in hierdie verlate gebiede te bevorder, wat 'n groter diversiteit van miskewers, groter ekosisteemfunksie en verhoogde ekosisteemdienste sal ondersteun.Master

Community pharmacy interventions for health promotion: effects on professional practice and health outcomes (Protocol)

This is the protocol for a review and there is no abstract. The objectives are as follows: Primary objective To assess the effectiveness of health promotion interventions in community pharmacy practice settings on pharmacy workers and pharmacy clients (including diagnosed patients) when compared to i) No treatment controls ii) Usual treatment controls iii) Other active intervention Secondary objectives To assess whether there are differences in effectiveness of health promotion interventions in community pharmacy practice settings on i) Pharmacy worker ii) Client (patient) with regard to: i) Ethnicity of patients ii) Country income level (World Bank Group 2009) iii) Extent of adverse health behaviour (defined according to national guidelines where available) iv) Type of pharmacy worker delivering the intervention (e.g. pharmacist versus pharmacist technician) v) Theoretical constructs/components and behaviour change techniques employed in the intervention vi) Costs of health car

Stellar Iron Abundances at the Galactic Center

We present measurements of [Fe/H] for six M supergiant stars and three giant stars within 0.5 pc of the Galactic Center (GC) and one M supergiant star within 30 pc of the GC. The results are based on high-resolution (lambda / Delta lambda =40,000) K-band spectra, taken with CSHELL at the NASA Infrared Telescope Facility.We determine the iron abundance by detailed abundance analysis,performed with the spectral synthesis program MOOG.The mean [Fe/H] of the GC stars is determined to be near solar,[Fe/H] = +0.12 $\pm$ 0.22. Our analysis is a differential analysis, as we have observed and applied the same analysis technique to eleven cool, luminous stars in the solar neighborhood with similar temperatures and luminosities as the GC stars. The mean [Fe/H] of the solar neighborhood comparison stars, [Fe/H] = +0.03 $\pm$ 0.16, is similar to that of the GC stars. The width of the GC [Fe/H] distribution is found to be narrower than the width of the [Fe/H] distribution of Baade's Window in the bulge but consistent with the width of the [Fe/H] distribution of giant and supergiant stars in the solar neighborhood.Comment: 41 pages, 9 figures, ApJ, in pres

Novel Insights Into Negative Pressure Wound Healing From an in Situ Porcine Perspective

Negative pressure wound therapy (NPWT) is used clinically to promote tissue formation and wound closure. In this study, a porcine wound model was used to further investigate the mechanisms as to how NPWT modulates wound healing via utilization of a form of NPWT called the vacuum-assisted closure. To observe the effect of NPWT more accurately, non-NPWT control wounds containing GranuFoam™ dressings, without vacuum exposure, were utilized. In situ histological analysis revealed that NPWT enhanced plasma protein adsorption throughout the GranuFoam™, resulting in increased cellular colonization and tissue ingrowth. Gram staining revealed that NPWT decreased bacterial dissemination to adjacent tissue with greater bacterial localization within the GranuFoam™. Genomic analysis demonstrated the significant changes in gene expression across a number of genes between wounds treated with non-NPWT and NPWT when compared against baseline tissue. However, minimal differences were noted between non-NPWT and NPWT wounds, including no significant differences in expression of collagen, angiogenic, or key inflammatory genes. Similarly, significant increases in immune cell populations were observed from day 0 to day 9 for both non-NPWT and NPWT wounds, though no differences were noted between non-NPWT and NPWT wounds. Furthermore, histological analysis demonstrated the presence of a foreign body response (FBR), with giant cell formation and encapsulation of GranuFoam™ particles. The unique in situ histological evaluation and genomic comparison of non-NPWT and NPWT wounds in this pilot study provided a never-before-shown perspective, offering novel insights into the physiological processes of NPWT and the potential role of a FBR in NPWT clinical outcomes

The analysis of gut microbiota in patients with bile acid diarrhoea treated with colesevelam

© 2023 The Authors. Published by Frontiers Media. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.3389/fmicb.2023.1134105Introduction: Bile acid diarrhoea (BAD) is a common disorder that results from an increased loss of primary bile acids and can result in a change in microbiome. The aims of this study were to characterise the microbiome in different cohorts of patients with BAD and to determine if treatment with a bile acid sequestrant, colesevelam, can alter the microbiome and improve microbial diversity. Materials and methods: Patients with symptoms of diarrhoea underwent 75-selenium homocholic acid (75SeHCAT) testing and were categorised into four cohorts: idiopathic BAD, post-cholecystectomy BAD, post-operative Crohn’s disease BAD and 75SeHCAT negative control group. Patients with a positive 75SeHCAT (<15%) were given a trial of treatment with colesevelam. Stool samples were collected pre-treatment, 4-weeks, 8-weeks and 6–12 months post-treatment. Faecal 16S ribosomal RNA gene analysis was undertaken. Results: A total of 257 samples were analysed from 134 patients. α-diversity was significantly reduced in patients with BAD and more specifically, in the idiopathic BAD cohort and in patients with severe disease (SeHCAT <5%); p < 0.05. Colesevelam did not alter bacterial α/β-diversity but patients who clinically responded to treatment had a significantly greater abundance of Fusobacteria and Ruminococcus, both of which aid in the conversion of primary to secondary bile acids. Conclusion: This is the first study to examine treatment effects on the microbiome in BAD, which demonstrated a possible association with colesevelam on the microbiome through bile acid modulation in clinical responders. Larger studies are now needed to establish a causal relationship with colesevelam and the inter-crosstalk between bile acids and the microbiome.The research department of MB received project funding from Bowel and Cancer Research for part of this work. The research department of MB received project funding from an unrestricted grant from Tillotts Pharma for part of this work.Published versio

Membrane transporters studied by EPR spectroscopy: structure determination and elucidation of functional dynamics

During their mechanistic cycles membrane transporters often undergo extensive conformational changes, sampling a range of orientations, in order to complete their function. Such membrane transporters present somewhat of a challenge to conventional structural studies; indeed, crystallization of membrane-associated proteins sometimes require conditions that vary vastly from their native environments. Moreover, this technique currently only allows for visualization of single selected conformations during any one experiment. EPR spectroscopy is a magnetic resonance technique that offers a unique opportunity to study structural, environmental and dynamic properties of such proteins in their native membrane environments, as well as readily sampling their substrate-binding-induced dynamic conformational changes especially through complementary computational analyses. Here we present a review of recent studies that utilize a variety of EPR techniques in order to investigate both the structure and dynamics of a range of membrane transporters and associated proteins, focusing on both primary (ABC-type transporters) and secondary active transporters which were key interest areas of the late Professor Stephen Baldwin to whom this review is dedicated

GENCODE: reference annotation for the human and mouse genomes in 2023.

GENCODE produces high quality gene and transcript annotation for the human and mouse genomes. All GENCODE annotation is supported by experimental data and serves as a reference for genome biology and clinical genomics. The GENCODE consortium generates targeted experimental data, develops bioinformatic tools and carries out analyses that, along with externally produced data and methods, support the identification and annotation of transcript structures and the determination of their function. Here, we present an update on the annotation of human and mouse genes, including developments in the tools, data, analyses and major collaborations which underpin this progress. For example, we report the creation of a set of non-canonical ORFs identified in GENCODE transcripts, the LRGASP collaboration to assess the use of long transcriptomic data to build transcript models, the progress in collaborations with RefSeq and UniProt to increase convergence in the annotation of human and mouse protein-coding genes, the propagation of GENCODE across the human pan-genome and the development of new tools to support annotation of regulatory features by GENCODE. Our annotation is accessible via Ensembl, the UCSC Genome Browser and https://www.gencodegenes.org