690 research outputs found
SUSTAINABILITY OF ORGANIC DAIRYING IN CANADA
The distinctive production characteristics and economic performance of organic dairy farms in central Canada has been documented, but the sustainability of these systems with respect to farm nutrient flows is less well understood. We have assessed farm management, livestock productivity, and nutrient status of fifteen long term (>10y) certified organic dairy farms in Ontario, Canada. Farm size, herd size and herd productivity averaged 110 ha, 52 cows and 8207 kg milk cow yr-1, respectively. Cropping composition differed little between farms, with pasture and forage accounting for an average of 65% of the cropped landbase. Annual farm nutrient budgets (inputs-outputs) over two years (2003-2005) for N, P and K were 52, 1 and 11 kg ha-1 yr-1, respectively. The majority (13) of farms had positive K budgets with half of the farms recording negative annual P budgets. Nutrient budget results were supported by soil fertility data generated by sampling 80% of farm fields (n=225). Overall, these results contrast strongly with large nutrient surpluses reported for more intensive, confinement-based dairy farms throughout N. America, but suggest a challenge to remain sustainable over the longer term for the 50% of these farms adopting a broadly ‘self-sufficient’ approach, and importing little P (0 - 2.5 kg ha-1 yr-1) as feed and feed supplements
Edible crabs “Go West”: migrations and incubation cycle of Cancer pagurus revealed by electronic tags
Crustaceans are key components of marine ecosystems which, like other exploited marine taxa, show seasonable patterns of distribution and activity, with consequences for their availability to capture by targeted fisheries. Despite concerns over the sustainability of crab fisheries worldwide, difficulties in observing crabs’ behaviour over their annual cycles, and the timings and durations of reproduction, remain poorly understood. From the release of 128 mature female edible crabs tagged with electronic data storage tags (DSTs), we demonstrate predominantly westward migration in the English Channel. Eastern Channel crabs migrated further than western Channel crabs, while crabs released outside the Channel showed little or no migration. Individual migrations were punctuated by a 7-month hiatus, when crabs remained stationary, coincident with the main period of crab spawning and egg incubation. Incubation commenced earlier in the west, from late October onwards, and brooding locations, determined using tidal geolocation, occurred throughout the species range. With an overall return rate of 34%, our results demonstrate that previous reluctance to tag crabs with relatively high-cost DSTs for fear of loss following moulting is unfounded, and that DSTs can generate precise information with regards life-history metrics that would be unachievable using other conventional means
Predominance of multidrug-resistant bacteria causing urinary tract infections among symptomatic patients in East Africa : a call for action
Background In low- and middle-income countries, antibiotics are often prescribed for patients with symptoms of urinary tract infections (UTIs) without microbiological confirmation. Inappropriate antibiotic use can contribute to antimicrobial resistance (AMR) and the selection of MDR bacteria. Data on antibiotic susceptibility of cultured bacteria are important in drafting empirical treatment guidelines and monitoring resistance trends, which can prevent the spread of AMR. In East Africa, antibiotic susceptibility data are sparse. To fill the gap, this study reports common microorganisms and their susceptibility patterns isolated from patients with UTI-like symptoms in Kenya, Tanzania and Uganda. Within each country, patients were recruited from three sites that were sociodemographically distinct and representative of different populations. Methods UTI was defined by the presence of >104 cfu/mL of one or two uropathogens in mid-stream urine samples. Identification of microorganisms was done using biochemical methods. Antimicrobial susceptibility testing was performed by the Kirby–Bauer disc diffusion assay. MDR bacteria were defined as isolates resistant to at least one agent in three or more classes of antimicrobial agents. Results Microbiologically confirmed UTI was observed in 2653 (35.0%) of the 7583 patients studied. The predominant bacteria were Escherichia coli (37.0%), Staphylococcus spp. (26.3%), Klebsiella spp. (5.8%) and Enterococcus spp. (5.5%). E. coli contributed 982 of the isolates, with an MDR proportion of 52.2%. Staphylococcus spp. contributed 697 of the isolates, with an MDR rate of 60.3%. The overall proportion of MDR bacteria (n = 1153) was 50.9%. Conclusions MDR bacteria are common causes of UTI in patients attending healthcare centres in East African countries, which emphasizes the need for investment in laboratory culture capacity and diagnostic algorithms to improve accuracy of diagnosis that will lead to appropriate antibiotic use to prevent and control AMR.Peer reviewe
"Just Going Through the Motions.…": A Qualitative Exploration of Athlete Perceptions of Social Loafing in Training and Competition Contexts - Implications for Team Sport Coaches
Semi-structured interviews were conducted with twenty team sport athletes representing a range of different sports with the aim of investigating their views relating to social loafing in training and competition. General themes investigated and subsequent content analysis highlighted
factors that promote or reduce the extent of social loafing. Determinants of self-loafing were grouped according to three distinct categories: Group processes; Task characteristics and Individual perceptions. Social loafing among others was perceived to be prevalent in both the training and competition scenarios with more examples of social loafing provided in the training situation. The signs of social loafing were grouped according to the
following themes: Cognitive & Emotional, Behavioural, Communication and Player Intuition. Consequences of social loafing were found to be detrimental to the effort and performance of both the individual and the team. Athletes were also able to differentiate between perceived social loafing and the perceived use of ‘strategic rest’ in team sports. Implications for the coaching process are far reaching with the need to develop an effective team culture and to provide training sessions that are interesting, engaging and relevant
International Survey to Establish Prioritized Outcomes for Trials in People With Coronavirus Disease 2019.
OBJECTIVES: There are over 4,000 trials conducted in people with coronavirus disease 2019. However, the variability of outcomes and the omission of patient-centered outcomes may diminish the impact of these trials on decision-making. The aim of this study was to generate a consensus-based, prioritized list of outcomes for coronavirus disease 2019 trials. DESIGN: In an online survey conducted in English, Chinese, Italian, Portuguese, and Spanish languages, adults with coronavirus disease 2019, their family members, health professionals, and the general public rated the importance of outcomes using a 9-point Likert scale (7-9, critical importance) and completed a Best-Worst Scale to estimate relative importance. Participant comments were analyzed thematically. SETTING: International. SUBJECTS: Adults 18 years old and over with confirmed or suspected coronavirus disease 2019, their family members, members of the general public, and health professionals (including clinicians, policy makers, regulators, funders, and researchers). INTERVENTIONS: None. MEASUREMENTS: None. MAIN RESULTS: In total, 9,289 participants from 111 countries (776 people with coronavirus disease 2019 or family members, 4,882 health professionals, and 3,631 members of the public) completed the survey. The four outcomes of highest priority for all three groups were: mortality, respiratory failure, pneumonia, and organ failure. Lung function, lung scarring, sepsis, shortness of breath, and oxygen level in the blood were common to the top 10 outcomes across all three groups (mean > 7.5, median ≥ 8, and > 70% of respondents rated the outcome as critically important). Patients/family members rated fatigue, anxiety, chest pain, muscle pain, gastrointestinal problems, and cardiovascular disease higher than health professionals. Four themes underpinned prioritization: fear of life-threatening, debilitating, and permanent consequences; addressing knowledge gaps; enabling preparedness and planning; and tolerable or infrequent outcomes. CONCLUSIONS: Life-threatening respiratory and other organ outcomes were consistently highly prioritized by all stakeholder groups. Patients/family members gave higher priority to many patient-reported outcomes compared with health professionals.The project is funded by the Flinders University and the National COVID-19 Clinical Evidence Taskforce, convened by the Australian Living Evidence Consortium, hosted by Cochrane Australia, School of Public Health and Preventive Medicine, Monash University supported by the Australian Government, Victorian Department of Health and Human Services, Ian Potter Foundation, Walter Cottman Endowment Fund (managed by Equity Trustees) and the Lord Mayor's Charitable Foundation). AT is supported by The University of Sydney Robinson Fellowship. ACM is supported by a Clinical Research Career Development Fellowship from the Wellcome Trust (WT 2055214/Z/16/Z
Silencing, Positive Selection and Parallel Evolution: Busy History of Primate Cytochromes c
Cytochrome c (cyt c) participates in two crucial cellular processes, energy production and apoptosis, and unsurprisingly is a highly conserved protein. However, previous studies have reported for the primate lineage (i) loss of the paralogous testis isoform, (ii) an acceleration and then a deceleration of the amino acid replacement rate of the cyt c somatic isoform, and (iii) atypical biochemical behavior of human cyt c. To gain insight into the cause of these major evolutionary events, we have retraced the history of cyt c loci among primates. For testis cyt c, all primate sequences examined carry the same nonsense mutation, which suggests that silencing occurred before the primates diversified. For somatic cyt c, maximum parsimony, maximum likelihood, and Bayesian phylogenetic analyses yielded the same tree topology. The evolutionary analyses show that a fast accumulation of non-synonymous mutations (suggesting positive selection) occurred specifically on the anthropoid lineage root and then continued in parallel on the early catarrhini and platyrrhini stems. Analysis of evolutionary changes using the 3D structure suggests they are focused on the respiratory chain rather than on apoptosis or other cyt c functions. In agreement with previous biochemical studies, our results suggest that silencing of the cyt c testis isoform could be linked with the decrease of primate reproduction rate. Finally, the evolution of cyt c in the two sister anthropoid groups leads us to propose that somatic cyt c evolution may be related both to COX evolution and to the convergent brain and body mass enlargement in these two anthropoid clades
Core Outcomes Set for Trials in People With Coronavirus Disease 2019.
OBJECTIVES: The outcomes reported in trials in coronavirus disease 2019 are extremely heterogeneous and of uncertain patient relevance, limiting their applicability for clinical decision-making. The aim of this workshop was to establish a core outcomes set for trials in people with suspected or confirmed coronavirus disease 2019. DESIGN: Four international online multistakeholder consensus workshops were convened to discuss proposed core outcomes for trials in people with suspected or confirmed coronavirus disease 2019, informed by a survey involving 9,289 respondents from 111 countries. The transcripts were analyzed thematically. The workshop recommendations were used to finalize the core outcomes set. SETTING: International. SUBJECTS: Adults 18 years old and over with confirmed or suspected coronavirus disease 2019, their family members, members of the general public and health professionals (including clinicians, policy makers, regulators, funders, researchers). INTERVENTIONS: None. MEASUREMENTS: None. MAIN RESULTS: Six themes were identified. "Responding to the critical and acute health crisis" reflected the immediate focus on saving lives and preventing life-threatening complications that underpinned the high prioritization of mortality, respiratory failure, and multiple organ failure. "Capturing different settings of care" highlighted the need to minimize the burden on hospitals and to acknowledge outcomes in community settings. "Encompassing the full trajectory and severity of disease" was addressing longer term impacts and the full spectrum of illness (e.g. shortness of breath and recovery). "Distinguishing overlap, correlation and collinearity" meant recognizing that symptoms such as shortness of breath had distinct value and minimizing overlap (e.g. lung function and pneumonia were on the continuum toward respiratory failure). "Recognizing adverse events" refers to the potential harms of new and evolving interventions. "Being cognizant of family and psychosocial wellbeing" reflected the pervasive impacts of coronavirus disease 2019. CONCLUSIONS: Mortality, respiratory failure, multiple organ failure, shortness of breath, and recovery are critically important outcomes to be consistently reported in coronavirus disease 2019 trials
Coexisting Cyclic Parthenogens Comprise a Holocene Species Flock in Eubosmina
Background: Mixed breeding systems with extended clonal phases and weak sexual recruitment are widespread in nature but often thought to impede the formation of discrete evolutionary clusters. Thus, cyclic parthenogens, such as cladocerans and rotifers, could be predisposed to ‘‘species problems’ ’ and a lack of discrete species. However, species flocks have been proposed for one cladoceran group, Eubosmina, where putative species are sympatric, and there is a detailed paleolimnological record indicating a Holocene age. These factors make the Eubosmina system suitable for testing the hypotheses that extended clonal phases and weak sexual recruitment inhibit speciation. Although common garden experiments have revealed a genetic component to the morphotypic variation, the evolutionary significance of the morphotypes remains controversial. Methodology/Principal Findings: In the present study, we tested the hypothesis of a single polymorphic species (i.e., mixing occurs but selection maintains genes for morphology) in four northern European lakes where the morphotypes coexist. Our evidence is based on nuclear DNA sequence, mitochondrial DNA sequence, and morphometric analysis of coexisting morphotypes. We found significant genetic differentiation, genealogical exclusivity, and morphometric differentiation for coexisting morphotypes. Conclusions: We conclude that the studied morphotypes represent a group of young species undergoing speciation wit
Brain Deletion of Insulin Receptor Substrate 2 Disrupts Hippocampal Synaptic Plasticity and Metaplasticity
Diabetes mellitus is associated with cognitive deficits and an increased risk of dementia, particularly in the elderly. These deficits and the corresponding neurophysiological structural and functional alterations are linked to both metabolic and vascular changes, related to chronic hyperglycaemia, but probably also defects in insulin action in the brain. To elucidate the specific role of brain insulin signalling in neuronal functions that are relevant for cognitive processes we have investigated the behaviour of neurons and synaptic plasticity in the hippocampus of mice lacking the insulin receptor substrate protein 2 (IRS-2)
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