285 research outputs found

    Estimates of genetic parameters of distal limb fracture and superficial digital flexor tendon injury in UK Thoroughbred racehorses

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    A retrospective cohort study of distal limb fracture and superficial digital flexor tendon (SDFT) injury in Thoroughbred racehorses was conducted using health records generated by the British Horseracing Authority (BHA) between 2000 and 2010. After excluding records of horses that had both flat and jump racing starts, repeated records were reduced to a single binary record per horse (<i>n</i> = 66,507, 2982 sires), and the heritability of each condition was estimated using residual maximum likelihood (REML) with animal logistic regression models. Similarly, the heritability of each condition was estimated for the flat racing and jump racing populations separately. Bivariate mixed models were used to generate estimates of genetic correlations between SDFT injury and distal limb fracture. The heritability of distal limb fracture ranged from 0.21 to 0.37. The heritability of SDFT injury ranged from 0.31 to 0.34. SDFT injury and distal limb fracture were positively genetically correlated. These findings suggest that reductions in the risk of the conditions studied could be attempted using targeted breeding strategies

    Heavy metal contamination in South African medicinal plants: A cause for concern

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    AbstractThe quality and safety of herbal medicines is becoming a major concern worldwide particularly due to contamination by heavy metals. The present study quantified the levels of heavy metals in frequently used South African medicinal plants and determined the variations in certain biological activities and phytochemical compositions. Eleven plant species were obtained from both muthi shops (MS) (commercial outlets) and from open street markets (OSM) for comparison. Samples were dried, powdered and digested using microwave acid-assisted digestion. The digested solutions were analysed for heavy metals using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). Plants were classified based on their elemental composition using chemometric techniques. Powdered plant samples were extracted using 70% acetone and screened for antibacterial activity against E. coli and S. aureus. Phytochemical analyses were carried out to determine total phenolic and flavonoid content. Of the 22 samples analysed, Bulbine natalensis obtained from OSM and Alepidea amatymbica obtained from MS exhibited high levels of Al [5559 and 4392mg/kg dry weight (DW)] and Fe (4164 and 4465mg/kg DW) respectively. Levels of As and Hg were above the World Health Organization permissible limits in most of the samples analysed. Hierarchical cluster analysis classified the samples into four groups based on their metallic analyte concentrations. Group one having low metal content and group four having a high metal content. In general, plant samples with high levels of metals yielded greater antibacterial activity. However, antibacterial activity recorded in this study is not an indicator of high levels of heavy metal contamination as some samples despite the high levels of metal exhibited low antibacterial activity. The variations in the amounts of phenolics and flavonoids in the evaluated samples could have probably been that some of the plant samples may have been harvested from different localities or at different times of the year, perhaps plant age or degree of storage. The results highlighted the need for in-depth risk and quality assessments

    Potential medicinal value of some South African seaweeds

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    Eleven macroalgae were collected from the KwaZulu-Natal coast and nineteen species from the cooler Western Cape coast in March and April 2000. Ethanolic and aqueous extracts were made and tested for biological activity in the Cox-1 anti-inflammatory assay, in a nematode mortality bioassay for anthelminthic activity, an IC50 anticancer assay and a MIC antimicrobial assay. The ethanolic extracts were very active in the Cox-1 anti-inflammatory assay for almost all of the species tested. The aqueous extracts were not active. No anthelminthic mortality was detected in extracts from any of the species tested. Many of the extracts had cytotoxic activity against three cancer cell lines tested, with those from representative species of the Chlorophyta and Rhodophyta being the most effective. The extracts had much lower cytotoxic activity when tested on normal mouse fibroblasts (NIH3T3). Extracts from only a few species had antimicrobial activity with those of the Chlorophyta tested being the most effective against both the Gram-positive and Gram-negative bacteria

    Ego depletion in visual perception: Ego-depleted viewers experience less ambiguous figure reversal.

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    This study examined the effects of ego depletion on ambiguous figure perception. Adults (N = 315) received an ego depletion task and were subsequently tested on their inhibitory control abilities that were indexed by the Stroop task (Experiment 1) and their ability to perceive both interpretations of ambiguous figures that was indexed by reversal (Experiment 2). Ego depletion had a very small effect on reducing inhibitory control (Cohen's d = .15) (Experiment 1). Ego-depleted participants had a tendency to take longer to respond in Stroop trials. In Experiment 2, ego depletion had small to medium effects on the experience of reversal. Ego-depleted viewers tended to take longer to reverse ambiguous figures (duration to first reversal) when naïve of the ambiguity and experienced less reversal both when naïve and informed of the ambiguity. Together, findings suggest that ego depletion has small effects on inhibitory control and small to medium effects on bottom-up and top-down perceptual processes. The depletion of cognitive resources can reduce our visual perceptual experience

    Estimates of genetic parameters of distal limb fracture and superficial digital flexor tendon injury in UK Thoroughbred racehorses

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    A B S T R A C T A retrospective cohort study of distal limb fracture and superficial digital flexor tendon (SDFT) injury in Thoroughbred racehorses was conducted using health records generated by the British Horseracing Authority (BHA) between 2000 and 2010. After excluding records of horses that had both flat and jump racing starts, repeated records were reduced to a single binary record per horse (n = 66,507, 2982 sires), and the heritability of each condition was estimated using residual maximum likelihood (REML) with animal logistic regression models. Similarly, the heritability of each condition was estimated for the flat racing and jump racing populations separately. Bivariate mixed models were used to generate estimates of genetic correlations between SDFT injury and distal limb fracture. The heritability of distal limb fracture ranged from 0.21 to 0.37. The heritability of SDFT injury ranged from 0.31 to 0.34. SDFT injury and distal limb fracture were positively genetically correlated. These findings suggest that reductions in the risk of the conditions studied could be attempted using targeted breeding strategies

    Durvalumab for the Treatment of Locally Advanced, Unresectable, Stage III Non-Small Cell Lung Cancer:An Evidence Review Group Perspective of a NICE Single Technology Appraisal

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    As part of the Single Technology Appraisal (STA) process, the National Institute for Health and Care Excellence (NICE) invited the manufacturer (AstraZeneca) of durvalumab (IMFINZI(TM)) to submit evidence for the clinical and cost effectiveness of durvalumab for the treatment of patients with locally advanced, unresectable, stage III non-small cell lung cancer whose tumours express programmed death-ligand 1 (PD-L1) on >= 1% of tumour cells and whose disease has not progressed after platinum-based chemoradiation therapy. Kleijnen Systematic Reviews Ltd, in collaboration with Maastricht University Medical Centre, was commissioned to act as the independent Evidence Review Group (ERG). This paper summarises the company submission (CS), presents the ERG's critical review on the clinical- and cost-effectiveness evidence in the CS, highlights the key methodological considerations, and describes the development of the NICE guidance by the Appraisal Committee. The CS included a systematic review that identified one randomised controlled trial, comparing durvalumab with SoC. Participants with tumours expressing PD-L1 on >= 1% of tumour cells accounted for approximately 40% of the total participants. In this subgroup, a benefit in progression-free survival (PFS) [hazard ratio (HR) 0.44, 95% confidence interval (CI) 0.31-0.63] and overall survival (HR 0.54, 95% CI 0.35-0.81) was reported. Adverse events were comparable between both treatments, but more serious adverse events were reported for durvalumab (64/213 [30%] vs. 18/90 [20%]). The ERG's concerns regarding the economic analysis included a likely overestimation of PFS for the durvalumab arm, the choice of timepoint for treatment waning, as well as the way treatment waning was incorporated in the model, and potential overestimation of utility values without applying an age- or treatment-related decrement. The revised ERG base-case resulted in a deterministic incremental cost-effectiveness ratio of 50,238 pound per quality-adjusted life-year gained, with substantial remaining uncertainty. NICE recommended durvalumab as an option for use within the Cancer Drugs Fund only in a subpopulation (concurrent platinum-based chemoradiation therapy) with a commercially managed access agreement in place

    Risk factors for race-day fatality in flat racing Thoroughbreds in Great Britain (2000 to 2013)

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    A key focus of the racing industry is to reduce the number of race-day events where horses die suddenly or are euthanased due to catastrophic injury. The objective of this study was therefore to determine risk factors for race-day fatalities in Thoroughbred racehorses, using a cohort of all horses participating in flat racing in Great Britain between 2000 and 2013. Horse-, race- and course-level data were collected and combined with all race-day fatalities, recorded by racecourse veterinarians in a central database. Associations between exposure variables and fatality were assessed using logistic regression analyses for (1) all starts in the dataset and (2) starts made on turf surfaces only. There were 806,764 starts in total, of which 548,571 were on turf surfaces. A total of 610 fatalities were recorded; 377 (61.8%) on turf. In both regression models, increased firmness of the going, increasing racing distance, increasing average horse performance, first year of racing and wearing eye cover for the first time all increased the odds of fatality. Generally, the odds of fatality also increased with increasing horse age whereas increasing number of previous starts reduced fatality odds. In the ‘all starts’ model, horses racing in an auction race were at 1.46 (95% confidence interval (CI) 1.06–2.01) times the odds of fatality compared with horses not racing in this race type. In the turf starts model, horses racing in Group 1 races were at 3.19 (95% CI 1.71–5.93) times the odds of fatality compared with horses not racing in this race type. Identification of novel risk factors including wearing eye cover and race type will help to inform strategies to further reduce the rate of fatality in flat racing horses, enhancing horse and jockey welfare and safety

    Stochastic descriptors to study the fate and potential of naive T cell clonotypes in the periphery

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    The population of naive T cells in the periphery is best described by determining both its T cell receptor diversity, or number of clonotypes, and the sizes of its clonal subsets. In this paper, we make use of a previously introduced mathematical model of naive T cell homeostasis, to study the fate and potential of naive T cell clonotypes in the periphery. This is achieved by the introduction of several new stochastic descriptors for a given naive T cell clonotype, such as its maximum clonal size, the time to reach this maximum, the number of proliferation events required to reach this maximum, the rate of contraction of the clonotype during its way to extinction, as well as the time to a given number of proliferation events. Our results show that two fates can be identified for the dynamics of the clonotype: extinction in the short-term if the clonotype experiences too hostile a peripheral environment, or establishment in the periphery in the long-term. In this second case the probability mass function for the maximum clonal size is bimodal, with one mode near one and the other mode far away from it. Our model also indicates that the fate of a recent thymic emigrant (RTE) during its journey in the periphery has a clear stochastic component, where the probability of extinction cannot be neglected, even in a friendly but competitive environment. On the other hand, a greater deterministic behaviour can be expected in the potential size of the clonotype seeded by the RTE in the long-term, once it escapes extinction
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