4,556 research outputs found
Come dine with me : food-associated social signalling in wild bottlenose dolphins (Tursiops truncatus)
The project was funded by a BBSRC Studentship to S.L.K., and a Royal Society University Research Fellowship and a Fellowship of the Wissenschaftskolleg Berlin to V.M.J.Food-related signalling is widespread in the animal kingdom with some food-associated vocalizations considered functionally referential. Food calls can, however, vary greatly in the type of information they convey. Thus, there are a multitude of purposes for which food calls are used, including social recruitment, caller spacing, the indication of type, quantity, quality, divisibility of food, the caller’s hunger level and even as tools to manipulate prey behaviour. Yet little work has focused on the social aspect of food calling in animals. We investigated the association of social signals in wild bottlenose dolphins with foraging behaviour where context-specific food-associated calls are commonly produced. Our data showed that specific social signals were significantly correlated with food call production and these calls rarely occurred in the absence of food calls. We suggest that animals are sharing additional information on the food patch itself with their social affiliates.PostprintPeer reviewe
Orthogeriatrics in Malta : a 3 year experience
The orthogeriatric service in Malta started in
2012 and expanded in 2014. From admission, the
patient is offered a ward based hip fracture
programme that includes orthogeriatric assessment,
management and co-ordinated multidisciplinary
review.
457 patients were seen by the orthogeriatric
service when this study was done. Mean age was 83
and 69% of patients were female. The Nottingham
Hip Fracture Score (NHFS) is a scoring system that
reliably predicts 30-day and 1-year mortality for
patients after hip fracture. It is made up of seven
independent predictors of postoperative mortality
that have been incorporated into a risk score. The
score ranges from 0-10 and the mean score for this
cohort was 5.1. There was a statistically significant
correlation between age and high NHFS scores. 30
day mortality was 5.9% and 1 year mortality was
24.4%. Compared with the Nottingham data both
30 day and 1 year mortality were less for the
orthogeriatric department in Malta.
The orthogeriatric service in Malta achieved
better results when comparing mortality with the
UK. In the future expansion of data collected should
be considered to better evaluate standards of care in
the department.peer-reviewe
The state of OA: a large-scale analysis of the prevalence and impact of Open Access articles
Despite growing interest in Open Access (OA) to scholarly literature, there is an unmet need for large-scale, up-to-date, and reproducible studies assessing the prevalence and characteristics of OA. We address this need using oaDOI, an open online service that determines OA status for 67 million articles. We use three samples, each of 100,000 articles, to investigateOAin three populations: (1) all journal articles assigned a Crossref DOI, (2) recent journal articles indexed in Web of Science, and (3) articles viewed by users of Unpaywall, an open-source browser extension that lets users find OA articles using oaDOI. We estimate that at least 28% of the scholarly literature is OA (19M in total) and that this proportion is growing, driven particularly by growth in Gold and Hybrid. The most recent year analyzed (2015) also has the highest percentage of OA (45%). Because of this growth, and the fact that readers disproportionately access newer articles, we find that Unpaywall users encounter OA quite frequently: 47% of articles they view are OA. Notably, the most common mechanism for OA is not Gold, Green, or Hybrid OA, but rather an under-discussed category we dub Bronze: articles made freeto- read on the publisher website, without an explicit Open license. We also examine the citation impact of OA articles, corroborating the so-called open-access citation advantage: accounting for age and discipline, OA articles receive 18% more citations than average, an effect driven primarily by Green and Hybrid OA.Weencourage further research using the free oaDOI service, as a way to inform OA policy and practice
Polymorphism and fighting in male fig wasps
Male fig wasps (Hymenoptera: Chalcidoidea) exhibit a fascinating range of morphology and behaviour. A cluster analysis, based on descriptions of the males of several hundred species, distinguished six major morphological groups. Behaviourial observations suggest that male morphology is related to the levels of inter-male aggression. Three behaviourial groupings were identified. Fighting species generally mated in the fig cavity, pacifist species mated in the females' galls or outside the figs. Mating sites are thus the primary determinants of male morphology and behaviour. In fighting species males were larger than their females, whereas pacifists and aggressors were equal in size or smaller than conspecific females. The large males in fighting fig wasps appear to be a consequence of sexual selection because larger males tended to win fights. Within a species there were no differences in the size of the galls that produced males and females, even in species where sexual size differences were present, suggesting that there is a heritable component to wasp size. No alternative advantages for smaller males were detected. Although fights were sometimes fatal, damage was not always a consequence of fighting behaviour and was recorded in both fighting and pacifist species. Sex ratios in several species were more female biased at higher population densities. Sex ratios of species with 'internally' ovipositing species were heavily female biased, but approached 1:1 in more outbred species with 'externally' ovipositing females. Levels of matedness, among females ranged from 73% to 99%. No evidence for sperm exhaustion was obtained. Species of Philotrypesis with both winged and flightless males were present only in southern African Ficus species from subsections Platyphyllae and Chlamydodorae. No species had only winged males. The flightless males of some Philotrypesis species were themselves polymorphic. In one polymorphic Philotrypesis species, winged males were found to be rare at high densities, but common at low densities. Digitata and religiosa males of Otitesella differed in coloration, size and behaviour. Digitata males were aggressors while religiosa males were fighters. Digitata males escaped from the figs whereas religiosa males remained inside the figs, perhaps because only digitata males were attracted to Light. Proportionally more digitata than religiosa males were present in low density populations and females were found to respond differently to the two morphs
LOW DOSE PPARγ AGONIST INHIBITION OF CYST GROWTH IN THE PCK RAT MODEL OF POLYCYSTIC KIDNEY DISEASE
poster abstractPolycystic kidney diseases (PKD) are genetic disorders characterized by fluid-filled cysts in kidney tubules and liver bile ducts that enlarge during the patient’s life commonly progressing to renal failure in midlife. Cyst enlarge-ment is due in part, to Cl- secretion via the cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channel. Our previous studies demonstrat-ed that PPARγ agonists, insulin-sensitizing drugs used to treat diabetes, in-hibit Cl- secretion by renal collecting duct principal cells via decreased CFTR synthesis. The dose response curves for Cl- transport paralleled the EC50’s for receptor transactivation with a leftward shift, suggesting an increased sensitivity for inhibition of Cl- secretion. Our previous preclinical studies showed that high (20 mg/kg BW) dose pioglitazone, a PPARγ agonist, inhib-ited cyst growth in the PCK rat model, which is orthologous to a human form of PKD. PCK rats were fed a diet containing 3 doses of rosiglitazone (4, 0.4, and 0.04 mg/kg BW) for 24 weeks starting at weaning. 4.0 mg/kg BW rosig-litazone is analogous to 20 mg/kg BW pioglitazone used in the previous study. At the end of the study, urine, serum, kidney, liver, and heart were collected for analysis. There was a significant decrease in total kidney weight, kidney weight as a percent of body weight, and renal cyst volume in the lowest does (0.04 mg/kg BW). There was no significance difference in the other doses, and the liver and heart were not changed significantly. This showed both pioglitazone and rosiglitazone were effective in inhibiting cyst growth in the PCK rat indicating a class action of PPARγ agonists. Important-ly, the rodent data substantiated the previous tissue culture data showing that a very low dose of rosiglitazone is effective in treatment of PKD
Inhibition of cyst growth in PCK and Wpk rat models of polycystic kidney disease with low doses of peroxisome proliferator-activated receptor γ agonists
Background and Objectives
The studies were designed to test the efficacy of two peroxisome proliferator-activated receptor γ (PPARγ) agonists in two rodent models of polycystic kidney disease (PKD).
Materials and Methods
The PCK rat is a slowly progressing cystic model while the Wpk-/- rat is a rapidly progressing model. PCK rats were fed with a pharmacological (0.4 mg/kg body weight [BW]) and a sub-pharmacological (0.04 mg/kg BW) dose of rosiglitazone (week 4–28). Wpk-/- rats were fed with pharmacological (2.0 mg/kg BW) and sub-pharmacologic (0.2 mg/kg BW) doses of pioglitazone from day 5 to 18. At termination, kidney weights of treated versus untreated cystic animals were used to determine efficacy. The current studies were also compared with previous studies containing higher doses of PPARγ agonists. The concentrations used in the animals were calculated with reference to equivalent human doses for both drugs.
Results
The current studies demonstrate: 1) that low, pharmacologically relevant, doses of the PPARγ agonists effectively inhibit cyst growth; 2) there is a class action of the drugs with both commercially available PPARγ agonists, rosiglitazone, and pioglitazone, inhibiting cyst growth; 3) the drugs showed efficacy in two different preclinical cystic models. In the PCK rat, animals fed with a sub-pharmacological dose of rosiglitazone for 24 weeks had significantly lower kidney weights than untreated animals (3.68 ± 0.13 g vs. 4.17 ± 0. 11 g, respectively, P < 0.01) while treatment with a pharmacologic dose had no significant effect on kidney weight. The rapidly progressing Wpk-/- rats were fed with pharmacological and sub-pharmacologic doses of pioglitazone from day 5 to 18 and the kidneys were compared with non-treated, cystic animals. Kidney weights on the pharmacologic dose were not statistically lower than the untreated animals while rats fed a sub-pharmacologic dose showed a significant decrease compared with untreated animals (3.35 ± 0.15 g vs. 4.55 ± 0.46 g, respectively, P = 0.045).
Conclusion
Concentrations of PPARγ agonists below the human equivalent diabetic doses are effective in slowing cyst growth in two rodent models of PKD
The genetic architecture of language functional connectivity
Available online 18 December 2021Language is a unique trait of the human species, of which the genetic architecture remains largely unknown. Through language disorders studies, many candidate genes were identified. However, such complex and multi- factorial trait is unlikely to be driven by only few genes and case-control studies, suffering from a lack of power, struggle to uncover significant variants. In parallel, neuroimaging has significantly contributed to the under- standing of structural and functional aspects of language in the human brain and the recent availability of large scale cohorts like UK Biobank have made possible to study language via image-derived endophenotypes in the general population. Because of its strong relationship with task-based fMRI (tbfMRI) activations and its easiness of acquisition, resting-state functional MRI (rsfMRI) have been more popularised, making it a good surrogate of functional neuronal processes. Taking advantage of such a synergistic system by aggregating effects across spa- tially distributed traits, we performed a multivariate genome-wide association study (mvGWAS) between genetic variations and resting-state functional connectivity (FC) of classical brain language areas in the inferior frontal (pars opercularis, triangularis and orbitalis), temporal and inferior parietal lobes (angular and supramarginal gyri), in 32,186 participants from UK Biobank. Twenty genomic loci were found associated with language FCs, out of which three were replicated in an independent replication sample. A locus in 3p11.1, regulating EPHA3 gene expression, is found associated with FCs of the semantic component of the language network, while a lo- cus in 15q14, regulating THBS1 gene expression is found associated with FCs of the perceptual-motor language processing, bringing novel insights into the neurobiology of language.This research was conducted using the UK Biobank resource un- der application #64984. This project was supported by the Marie Sklodowska-Curie program awarded to Stephanie J. Forkel (Grant agree- ment No. 101028551). Amaia Carrion-Castillo was supported by a Juan de la Cierva fellowship from the Spanish Ministry of Science and Innova- tion, and a Gipuzkoa Fellows fellowship from the Basque Governmen
Perturbed cholesterol and vesicular trafficking associated with dengue blocking in Wolbachia-infected Aedes aegypti cells
Wolbachia are intracellular maternally inherited bacteria that can spread through insect populations and block virus transmission by mosquitoes, providing an important approach to dengue control. To better understand the mechanisms of virus inhibition, we here perform proteomic quantification of the effects of Wolbachia in Aedes aegypti mosquito cells and midgut. Perturbations are observed in vesicular trafficking, lipid metabolism and in the endoplasmic reticulum that could impact viral entry and replication. Wolbachia-infected cells display a differential cholesterol profile, including elevated levels of esterified cholesterol, that is consistent with perturbed intracellular cholesterol trafficking. Cyclodextrins have been shown to reverse lipid accumulation defects in cells with disrupted cholesterol homeostasis. Treatment of Wolbachia-infected Ae. aegypti cells with 2-hydroxypropyl-β-cyclodextrin restores dengue replication in Wolbachia-carrying cells, suggesting dengue is inhibited in Wolbachia-infected cells by localised cholesterol accumulation. These results demonstrate parallels between the cellular Wolbachia viral inhibition phenotype and lipid storage genetic disorders
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