518 research outputs found

    High- cholesterol diet does not alter gut microbiota composition in mice

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    Introduction: Western diet containing both saturated fat and cholesterol impairs cardio- metabolic health partly by modulating diversity and function of the microbiota. While diet containing only high fat has comparable effects, it is unclear how diets only enriched in cholesterol impact the microbiota. Therefore, we aimed to characterize the response of host and microbiota to a high cholesterol ( HC) diet in mice susceptible to cardio- metabolic disease. Methods: LDLR knockout mice received either 1.25% HC or no cholesterol containing control diet ( NC) for 12 weeks before characterizing host cholesterol metabolism and intestinal microbiota composition ( next generation sequencing). Results: HC diet substantially increased plasma ( 1.6- fold) and liver cholesterol levels ( 21- fold), biliary cholesterol secretion ( 4.5- fold) and fecal neutral sterol excretion ( 68- fold, each p <0.001) but not fecal bile acid excretion. Interestingly, despite the profound changes in intestinal cholesterol homeostasis no differences in microbial composition between control and HC- fed mice were detected. In both groups the main phyla were Bacteroidetes ( 55%), Firmicutes ( 27%) and Verrucomicrobia ( 14%). Conclusion: Our results demonstrate that in mice HC diet alone does not alter the microbiota composition despite inducing substantial adaptive changes in whole body cholesterol homeostasis. The impact of Western diet on intestinal microbiota thus appears to be mediated exclusively by its high fat content

    A new approach to quantitative propagation of chaos for drift, diffusion and jump processes

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    This paper is devoted the the study of the mean field limit for many-particle systems undergoing jump, drift or diffusion processes, as well as combinations of them. The main results are quantitative estimates on the decay of fluctuations around the deterministic limit and of correlations between particles, as the number of particles goes to infinity. To this end we introduce a general functional framework which reduces this question to the one of proving a purely functional estimate on some abstract generator operators (consistency estimate) together with fine stability estimates on the flow of the limiting nonlinear equation (stability estimates). Then we apply this method to a Boltzmann collision jump process (for Maxwell molecules), to a McKean-Vlasov drift-diffusion process and to an inelastic Boltzmann collision jump process with (stochastic) thermal bath. To our knowledge, our approach yields the first such quantitative results for a combination of jump and diffusion processes.Comment: v2 (55 pages): many improvements on the presentation, v3: correction of a few typos, to appear In Probability Theory and Related Field

    Swimming against the tide: a study of a neighbourhood trying to rediscover its ‘reason for being’– the case of South Bank, Redcar and Cleveland.

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    Many of the programmes and initiatives to regenerate deprived neighbourhoods appear to have had limited lasting impact. It has been argued that one reason for this is that we still have little real understanding of the nature and scale of the problems some communities face (Bernt, 2009). This article attempts to add to our knowledge through close study of an area with multiple problems and a history of failed regeneration attempts. An in-depth case study, undertaken to explore the current situation and future prospects of South Bank, a small neighbourhood in the North East of England, highlights transferable knowledge which may be applied to other regeneration areas. The analysis considers the nature and consequences of industrial decline; entrenched deprivation; the stigmatization of communities; the value of community consultation and the potential impact of retail-led regeneration. We question whether negative stigma attached to places can be changed and we ask what the future may hold for deprived communities now that public sector funding has largely dried up, and we consider an alternative approach: the potential impacts of private sector retail-led regeneration in the absence of public sector funding

    The highly rearranged mitochondrial genomes of the crabs Maja crispata and Maja squinado (Majidae) and gene order evolution in Brachyura

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    Abstract We sequenced the mitochondrial genomes of the spider crabs Maja crispata and Maja squinado (Majidae, Brachyura). Both genomes contain the whole set of 37 genes characteristic of Bilaterian genomes, encoded on both \u3b1- and \u3b2-strands. Both species exhibit the same gene order, which is unique among known animal genomes. In particular, all the genes located on the \u3b2-strand form a single block. This gene order was analysed together with the other nine gene orders known for the Brachyura. Our study confirms that the most widespread gene order (BraGO) represents the plesiomorphic condition for Brachyura and was established at the onset of this clade. All other gene orders are the result of transformational pathways originating from BraGO. The different gene orders exhibit variable levels of genes rearrangements, which involve only tRNAs or all types of genes. Local homoplastic arrangements were identified, while complete gene orders remain unique and represent signatures that can have a diagnostic value. Brachyura appear to be a hot-spot of gene order diversity within the phylum Arthropoda. Our analysis, allowed to track, for the first time, the fully evolutionary pathways producing the Brachyuran gene orders. This goal was achieved by coupling sophisticated bioinformatic tools with phylogenetic analysis

    Broad-band spectrophotometry of HAT-P-32 b: search for a scattering signature in the planetary spectrum

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    Multicolour broad-band transit observations offer the opportunity to characterize the atmosphere of an extrasolar planet with small- to medium-sized telescopes. One of the most favourable targets is the hot Jupiter HAT-P-32 b. We combined 21 new transit observations of this planet with 36 previously published light curves for a homogeneous analysis of the broad-band transmission spectrum from the Sloan u′ band to the Sloan z′ band. Our results rule out cloud-free planetary atmosphere models of solar metallicity. Furthermore, a discrepancy at reddest wavelengths to previously published results makes a recent tentative detection of a scattering feature less likely. Instead, the available spectral measurements of HAT-P-32 b favour a completely flat spectrum from the near-UV to the near-IR. A plausible interpretation is a thick cloud cover at high altitudes

    Innovative approaches in investigating inter-beat intervals: Graph theoretical method suggests altered autonomic functioning in adolescents with ADHD

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    Cardiac inter-beat intervals (IBIs) are considered to reflect autonomic functioning and self-regulatory abilities and are often investigated by traditional time- and frequency domain analyses. These analyses investigate IBI fluctuations across relatively long time series. The similarity graph algorithm is a nonlinear method that analyzes segments of IBI time series (i.e., time windows)—possibly being more sensitive to transient and spontaneous IBI fluctuations. We hypothesized that the similarity graph algorithm would detect differences between Attention-Deficit/Hyperactivity Disorder (ADHD) and control groups. Resting electrocardiogram (ECG) recordings were collected in 10–18-year-olds with ADHD (n = 37) and controls (n = 36). IBIs were converted to graphs that were subsequently investigated for similarity. We varied the criterion for defining IBIs as similar, assessing which setting best distinguished ADHD and control groups. Using this setting, we applied the similarity graph algorithm to time windows of 2–5, 6–13 and 12–25 s, respectively. We also performed traditional IBI analyses. Independent samples t tests assessed group differences. Results showed that a 1.5% criterion of similarity and a time window of 2–5 s best distinguished adolescents with ADHD and controls. The similarity graph algorithm showed a higher number of edges, maximum edges and cliques, and lower edges10+10/edges2+2 in the ADHD group compared to controls. The results suggested more similar IBIs in the ADHD group compared to the controls, possibly due to altered vagal activity and less effective regulation of heart rate. Traditional analyses did not detect any group differences. Consequently, the similarity graph algorithm might complement traditional IBI analyses as a marker of psychopathology.publishedVersio

    Changes in Albuminuria Predict Cardiovascular and Renal Outcomes in Type 2 Diabetes: A Post Hoc Analysis of the LEADER Trial

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    OBJECTIVE A post hoc analysis to investigate the association between 1-year changes in albuminuria and subsequent risk of cardiovascular and renal events. RESEARCH DESIGN AND METHODS LEADER was a randomized trial of liraglutide up to 1.8 mg/day versus placebo added to standard care for 3.5-5 years in 9,340 participants with type 2 diabetes and high cardiovascular risk. We calculated change in urinary albumin-to-creatinine ratio (UACR) from baseline to 1 year in participants with >30% reduction (n = 2,928), 30-0% reduction (n = 1,218), or any increase in UACR (n = 4,124), irrespective of treatment. Using Cox regression, risks of major adverse cardiovascular events (MACE) and a composite nephropathy outcome (from 1 year to end of trial in subgroups by baseline UACR [= 300 mg/g]) were assessed. The analysis was adjusted for treatment allocation alone as a fixed factor and for baseline variables associated with cardiovascular and renal outcomes. RESULTS For MACE, hazard ratios (HRs) for those with >30% and 30-0% UACR reduction were 0.82 (95% CI 0.71, 0.94; P = 0.006) and 0.99 (0.82, 1.19; P = 0.912), respectively, compared with any increase in UACR (reference). For the composite nephropathy outcome, respective HRs were 0.67 (0.49, 0.93; P = 0.02) and 0.97 (0.66, 1.43; P = 0.881). Results were independent of baseline UACR and consistent in both treatment groups. After adjustment, HRs were significant and consistent in >30% reduction subgroups with baseline micro- or macroalbuminuria. CONCLUSIONS A reduction in albuminuria during the 1st year was associated with fewer cardiovascular and renal outcomes, independent of treatment. Albuminuria monitoring remains an important part of diabetes care, with great unused potential

    Cardiovascular and renal outcomes by baseline albuminuria status and renal function — results from the LEADER randomized trial

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    Aim: To assess cardiorenal outcomes by baseline urinary albumin-to-creatinine ratio (UACR) and estimated glomerular filtration rate (eGFR) in the contemporary LEADER cohort. Materials and methods: LEADER was a multinational, double-blind trial. Patients with type 2 diabetes and high cardiovascular (CV) risk were randomized 1:1 to the glucagon-like peptide-1 analogue liraglutide (≤1.8 mg daily; n = 4668) or placebo (n = 4672) plus standard care and followed for 3.5 to 5 years. Primary composite outcomes were time to first non-fatal myocardial infarction, non-fatal stroke or CV death. Post hoc Cox regression analyses of outcomes by baseline UACR and eGFR subgroups were conducted with adjustment for baseline variables. Results: In the LEADER population, 1598 (17.5%), 2917 (31.9%), 1200 (13.1%), 1611 (17.6%), 845 (9.2%) and 966 (10.6%) had UACR = 0, >0 to <15, 15 to <30, 30 to <100, 100 to <300 and ≥300 mg/g, respectively. Increasing UACR and decreasing eGFR were linked with higher risks of the primary outcome, heart failure hospitalization, a composite renal outcome and death (P-values for the Cochran-Armitage test for trends were all <.0001). Across UACR and eGFR subgroups, risks of cardiorenal events and death were generally lower or similar with liraglutide versus placebo. Conclusions: In a contemporary type 2 diabetes population, increasing baseline UACR and declining eGFR were linked with higher risks of cardiorenal events and death

    Surveillance of molecular markers for antimalarial resistance in Zambia: Polymorphism of Pfkelch 13, Pfmdr1 and Pfdhfr/Pfdhps genes

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    Antimalarial resistance is an inevitable feature of control efforts and a key threat to achieving malaria elimination. Plasmodium falciparum, the deadliest of several species causing human malaria, has developed resistance to essentially all antimalarials. This study sought to investigate the prevalence of molecular markers associated with resistance to sulfadoxine-pyrimethamine (SP) and artemether-lumefantrine (AL) in Southern and Western provinces in Zambia. SP is used primarily for intermittent preventive treatment during pregnancy, while AL is the first-line antimalarial for uncomplicated malaria in Zambia. Blood samples were collected from household members of all ages in a cross-sectional survey conducted during peak malaria transmission, April to May of 2017, and amplified by polymerase chain reaction (PCR). Amplicons were then analysed by high-resolution melt following PCR to identify mutations associated with SP resistance in the P. falciparum dihydrofolate reductase (Pfdhfr) and P. falciparum dihydropteroate synthase (Pfdhps) genes and lumefantrine resistance in the P. falciparum multi-drug resistance 1 (Pfmdr1) gene. Finally, artemether resistance was assessed in the P. falciparum Kelch 13 (PfK13) gene using nested PCR followed by amplicon sequencing. The results showed a high frequency of genotypic-resistant Pfdhps A437G (93.2%) and Pfdhfr C59R (86.7%), N51I (80.9%), and S108N (80.8%) of which a high proportion (82.4%) were quadruple mutants (Pfdhfr N51I, C59R, S108N +Pfdhps A437G). Pfmrd1 N86Y, Y186F, and D1246Y - NFD mutant haplotypes were observed in 41.9% of isolates. The high prevalence of quadruple dhps/dhfr mutants indicates strong antifolate drug pressure from SP or other drugs (e.g., co-trimoxazole). Three samples contained PfK13 mutations, two synonymous (T478 and V666) and one non-synonymous (A578S), none of which have been associated with delayed clearance. This suggests that artemisinin remains efficacious in Zambia, however, the moderately high prevalence of approximately 40% Pfmdr1 NFD mutations calls for close monitoring of AL.publishedVersio
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