274 research outputs found
A novel approach to using seabed geomorphology as a predictor of habitat use in highly mobile marine predators : implications for ecology and conservation
Department for Business, Energy, and Industrial Strategy (BEIS, formerly DECC) Offshore Energy Strategic Environmental Assessment programme funded the purchase of the tags and their deployment (OESEA-14-47) and supported HMEW (OESEA-20-118). DJFR was supported by NERC National Public Good- National Capability funding to SMRU (NE/R015007/1). MIDC was supported by project EcoSTAR, funded under NERC INSITE Phase II (grant no. NE/T010614/1). Funds for open access publication fees were from the research grants of supervisors at University of St Andrews.Understanding how marine predators find patchily distributed prey resources in a dynamic environment is key to identifying important ecological areas for ecosystem-level conservation management. However, the mechanisms underpinning important foraging areas often result from complex interactions between static and dynamic covariates (e.g. topography and currents). Modelling habitat associations with hydrodynamic processes is rarely useful when attempting to identify and characterise foraging areas across an individual’s foraging range. Investigating the influence of static habitat features on predator behaviour can provide a more tractable baseline understanding of habitat associations, upon which additional complexity can be added. Seabed gradient covariates (e.g. slope and aspect) are often used, yet such metrics are computed at singular user-defined resolutions, and provide limited ecological insight when used in isolation. Instead, categorising the seabed into geomorphological features may provide better characterisation of seabed structure. Here we explore the utility of a pattern recognition algorithm to delineate whole geomorphological features (“geomorphons”) on the seabed (e.g. valleys, ridges, footslopes) from bathymetry data, and examine the influence of geomorphology on marine predator habitat use. We demonstrate the potential application of this approach in a case study, examining the influence of geomorphons on the at-sea behaviour of a highly mobile predator inhabiting shelf seas: the grey seal (Halichoerus grypus). We analyse GPS tracking data from three seals tagged in the southern North Sea, an area with heterogeneous geomorphology. We use hidden Markov models (HMMs) to infer foraging and travelling behaviour and model the effect of different feature types on the probability of switching between states. All three seals showed an increased probability of transitioning from travelling to foraging when encountering slopes, footslopes and hollows, and foraging activity was concentrated at slopes on the fringes of the Dogger Bank. We hypothesise that such features may host prey aggregations, or lead to increased prey capture success. The results suggest the importance of such areas for grey seals in the southern North Sea, a region undergoing rapid and widespread anthropogenic habitat change. This method could be incorporated into future species distribution models to improve estimates of predator distribution, informing conservation management and marine spatial planning.Publisher PDFPeer reviewe
Update on hepatitis C virus resistance to direct-acting antiviral agents
Review[Abstract] Resistance to direct-acting antiviral (DAA) agents against hepatitis C virus (HCV) infection is driven by the selection of mutations at different positions in the NS3 protease, NS5B polymerase and NS5A proteins. With the exception of NS5B nucleos(t)ide inhibitors, most DAAs possess a low genetic barrier to resistance, with significant cross-resistance between compounds belonging to the same family. However, a specific mutation profile is associated with each agent or drug class and varies depending on the genotype/subtype (e.g., genotype 1b showed higher rates of sustained virological response (SVR) and a higher genetic barrier for resistance than genotype 1a). Moreover, some resistance mutations exist as natural polymorphisms in certain genotypes/subtypes at frequencies that require baseline drug resistance testing before recommending certain antivirals. For example, the polymorphism Q80K is frequently found among genotype 1a (19–48%) and is associated with resistance to simeprevir. Similarly, L31M and Y93H, key resistance mutations to NS5A inhibitors, are frequently found (6–12%) among NS5A genotype 1 sequences. In particular, the presence of these polymorphisms may be of relevance in poorly interferon-responsive patients (i.e., null responders and non-CC IL28B) under DAA-based therapies in combination with pegylated interferon-α plus ribavirin. The relevance of pre-existing resistance mutations for responses to interferon-free DAA therapies is unclear for most regimens and requires further study.Instituto de Salud Carlos III; CP08/00214Instituto de Salud Carlos III; PI10/0216
Aphanomyces-Resistant Alfalfa: A Solution to a Common Problem in Spring Seedings
For several decades, farmers have experienced a common stand-establishment disease syndrome when spring-seeded alfalfa was followed by extended periods of wet weather. Seedlings affected by this syndrome exhibit severe stunting as well as yellowing and reddening of seed leaves (cotyledons), but they do not wilt or collapse, as they might from a damping-off disease. Commonly, the problem affects most or all of the field.
Based on research that began in the 1980\u27s, we suspected that a fungus called Aphanomyces euteiches (hereafter simply called Aphanomyces) was responsible. This root-rot fungus can be found in the majority of alfalfa fields we have sampled in central and western Kentucky. However, for many years we lacked conclusive proof that Aphanomyces was, in fact, the cause of this common problem in spring-seeded alfalfa. We also did not have rigorous proof that the syndrome could be avoided by sowing Aphanomyces-resistant alfalfa varieties, which started becoming commercially available in the early 1990\u27s. In this report, we provide a brief summary of research to support our new recommendation: that spring-seeded alfalfa should be sown only with varieties having an R or HR rating to Aphanomyces root rot (ARR)
Development and implementation of the Structured Training Trainer Assessment Report (STTAR) in the English National Training Programme for laparoscopic colorectal surgery
Background: There is a lack of educational tools available for surgical teaching critique, particularly for advanced laparoscopic surgery. The aim was to develop and implement a tool that assesses training quality and structures feedback for trainers in the English National Training Programme for laparoscopic colorectal surgery. Methods: Semi-structured interviews were performed and analysed, and items were extracted. Through the Delphi process, essential items pertaining to desirable trainer characteristics, training structure and feedback were determined. An assessment tool (Structured Training Trainer Assessment Report—STTAR) was developed and tested for feasibility, acceptability and educational impact. Results: Interview transcripts (29 surgical trainers, 10 trainees, four educationalists) were analysed, and item lists created and distributed for consensus opinion (11 trainers and seven trainees). The STTAR consisted of 64 factors, and its web-based version, the mini-STTAR, included 21 factors that were categorised into four groups (training structure, training behaviour, trainer attributes and role modelling) and structured around a training session timeline (beginning, middle and end). The STTAR (six trainers, 48 different assessments) demonstrated good internal consistency (α = 0.88) and inter-rater reliability (ICC = 0.75). The mini-STTAR demonstrated good inter-item reliability (α = 0.79) and intra-observer reliability on comparison of 85 different trainer/trainee combinations (r = 0.701, p = <0.001). Both were found to be feasible and acceptable. The educational report for trainers was found to be useful (4.4 out of 5). Conclusions: An assessment tool that evaluates training quality was developed and shown to be reliable, acceptable and of educational value. It has been successfully implemented into the English National Training Programme for laparoscopic colorectal surgery
Safety and Efficacy of Ombitasvir, Paritaprevir With Ritonavir ± Dasabuvir With or Without Ribavirin in Patients With Human Immunodeficiency Virus-1 and Hepatitis C Virus Genotype 1 or Genotype 4 Coinfection: TURQUOISE-I Part 2.
BACKGROUND: Ombitasvir, paritaprevir with ritonavir, and dasabuvir (OBV/PTV/r ± DSV) ±ribavirin (RBV) are approved to treat hepatitis C virus (HCV) genotype 1 and 4 infection. Here, we investigate the safety and efficacy of OBV/PTV/r + DSV ±RBV for HCV genotype 1, and OBV/PTV/r + RBV for HCV genotype 4, in human immunodeficiency virus (HIV)-1 coinfected patients with or without compensated cirrhosis. METHODS: TURQUOISE-I, Part 2 is a phase 3 multicenter study. Patients with or without cirrhosis were HCV treatment-naive or -experienced, on an HIV-1 antiretroviral regimen containing atazanavir, raltegravir, dolutegravir, or darunavir (for genotype 4 only), and had plasma HIV-1 ribonucleic acid <40 copies/mL at screening. Patients received OBV/PTV/r ± DSV ±RBV for 12 or 24 weeks. RESULTS: In total, 228 patients were treated according to guidelines. Sustained virologic response at posttreatment week 12 (SVR12) was achieved by 194 of 200 (97%) and 27 of 28 (96%) patients with HCV genotype 1 and genotype 4 infection, respectively. There were 2 virologic failures: 1 breakthrough and 1 relapse in a cirrhotic and a noncirrhotic patient with genotype 1b and 1a infection, respectively. One reinfection occurred at posttreatment week 12 in a genotype 1a-infected patient. Excluding nonvirologic failures, the SVR12 rates were 98% (genotype 1) and 100% (genotype 4). Adverse events were mostly mild in severity and did not lead to discontinuation. Laboratory abnormalities were rare. CONCLUSIONS: The OBV/PTV/r ±DSV was well tolerated and yielded high SVR12 rates in patients with HCV genotype 1 or genotype 4/HIV-1 coinfection. The OBV/PTV/r ± DSV ±RBV is a potent HCV treatment option for patients with HIV-1 coinfection, regardless of treatment experience
Synchrotron analysis of human organ tissue exposed to implant material
Background
Orthopaedic implants made of cobalt-chromium alloy undergo wear and corrosion that can lead to deposition of cobalt and chromium in vital organs. Elevated cardiac tissue cobalt levels are associated with myocardial injury while chromium is a well-established genotoxin. Though metal composition of tissues surrounding hip implants has been established, few investigators attempted to characterize the metal deposits in systemic tissues of total joint arthroplasty patients.
Methods
We report the first use of micro-X-ray fluorescence coupled with micro-X-ray absorption spectroscopy to probe distribution and chemical form of cobalt, chromium and titanium in postmortem samples of splenic, hepatic and cardiac tissue of patients with metal-on-polyethylene hip implants (n = 5).
Results
Majority of the cobalt was in the 2+ oxidation state, while titanium was present exclusively as titanium dioxide, in either rutile or anatase crystal structure. Chromium was found in a range of forms including a highly oxidised, carcinogenic species (CrV/VI), which has never been identified in human tissue before.
Conclusions
Carcinogenic forms of chromium might arise in vital organs of total joint arthroplasty patients. Further studies are warranted with patients with metal-on-metal implants, which tend to have an increased release of cobalt and chromium compared to metal-on-polyethylene hips
Understanding Engagement, Marketing, and Motivation to Benefit Recruitment and Retention in Citizen Science
In November 2020, a meeting was held to explore what citizen science practitioners can gain from understanding engagement, marketing, and volunteer motivations in order to benefit recruitment and retention in environmental citizen science. This report summarises the lessons learned from considering the role of people as participants within citizen science; although we note that this is only one and, for some, a contested view of participants. Marketing and motivation studies highlighted the importance of knowing more about participants. Framing and user experience experts showed how to convert knowledge into tailored approaches that enhance engagement and retention. Other fields, including the world of commerce, have potential lessons for citizen science practitioners, especially those involved in top-down, mass participatory projects that require high levels of engagement
Oxysterol Binding Protein-dependent Activation of Sphingomyelin Synthesis in the Golgi Apparatus Requires Phosphatidylinositol 4-Kinase IIα
The study identifies a sterol- and oxysterol binding protein (OSBP)-regulated phosphatidylinositol 4-kinase that regulates ceramide transport protein (CERT) activity and sphingomyelin (SM) synthesis. RNA interference silencing experiments identify PI4KIIα; as the mediator of Golgi recruitment of CERT, providing a potential mechanism for coordinating assembly of SM and cholesterol in the Golgi or more distal compartments
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