2,045 research outputs found
Temperate southern Australian coastal waters are characterised by surprisingly high rates of nitrogen fixation and diversity of diazotrophs
Biological dinitrogen (N2) fixation is one mechanism by which specific microorganisms (diazotrophs) can ameliorate nitrogen (N) limitation. Historically, rates of N2 fixation were believed to be limited outside of the low nutrient tropical and subtropical open ocean; however, emerging evidence suggests that N2 fixation is also a significant process within temperate coastal waters. Using a combination of amplicon sequencing, targeting the nitrogenase reductase gene (nifH), quantitative nifH PCR, and 15N2 stable isotope tracer experiments, we investigated spatial patterns of diazotroph assemblage structure and N2 fixation rates within the temperate coastal waters of southern Australia during Austral autumn and summer. Relative to previous studies in open ocean environments, including tropical northern Australia, and tropical and temperate estuaries, our results indicate that high rates of N2 fixation (10–64 nmol L−1 d−1) can occur within the large inverse estuary Spencer Gulf, while comparatively low rates of N2 fixation (2 nmol L−1 d−1) were observed in the adjacent continental shelf waters. Across the dataset, low concentrations of NO3/NO2 were significantly correlated with the highest N2 fixation rates, suggesting that N2 fixation could be an important source of new N in the region as dissolved inorganic N concentrations are typically limiting. Overall, the underlying diazotrophic community was dominated by nifH sequences from Cluster 1 unicellular cyanobacteria of the UCYN-A clade, as well as non-cyanobacterial diazotrophs related to Pseudomonas stutzeri, and Cluster 3 sulfate-reducing deltaproteobacteria. Diazotroph community composition was significantly influenced by salinity and SiO4 concentrations, reflecting the transition from UCYN-A-dominated assemblages in the continental shelf waters, to Cluster 3-dominated assemblages in the hypersaline waters of the inverse estuary. Diverse, transitional diazotrophic communities, comprised of a mixture of UCYN-A and putative heterotrophic bacteria, were observed at the mouth and southern edge of Spencer Gulf, where the highest N2 fixation rates were observed. In contrast to observations in other environments, no seasonal patterns in N2 fixation rates and diazotroph community structure were apparent. Collectively, our findings are consistent with the emerging view that N2 fixation within temperate coastal waters is a previously overlooked dynamic and potentially important component of the marine N cycle
Hybridization and Back-Crossing in Giant Petrels (Macronectes giganteus and M. halli) at Bird Island, South Georgia, and a Summary of Hybridization in Seabirds
Hybridization in natural populations provides an opportunity to study the evolutionary processes that shape divergence and genetic isolation of species. The emergence of pre-mating barriers is often the precursor to complete reproductive isolation. However, in recently diverged species, pre-mating barriers may be incomplete, leading to hybridization between seemingly distinct taxa. Here we report results of a long-term study at Bird Island, South Georgia, of the extent of hybridization, mate fidelity, timing of breeding and breeding success in mixed and conspecific pairs of the sibling species, Macronectes halli (northern giant petrel) and M . giganteus (southern giant petrel). The proportion of mixed-species pairs varied annually from 0.4-2.4% (mean of 1.5%), and showed no linear trend with time. Mean laying date in mixed-species pairs tended to be later than in northern giant petrel, and always earlier than in southern giant petrel pairs, and their breeding success (15.6%) was lower than that of conspecific pairs. By comparison, mixed-species pairs at both Marion and Macquarie islands always failed before hatching. Histories of birds in mixed-species pairs at Bird Island were variable; some bred previously or subsequently with a conspecific partner, others subsequently with a different allospecific partner, and some mixed-species pairs remained together for multiple seasons. We also report the first verified back-crossing of a hybrid giant petrel with a female northern giant petrel. We discuss the potential causes and evolutionary consequences of hybridization and back-crossing in giant petrels and summarize the incidence of back-crossing in other seabird species
Contemplating Mindfulness at Work: An Integrative Review
Mindfulness research activity is surging within organizational science. Emerging evidence across multiple fields suggests that mindfulness is fundamentally connected to many aspects of workplace functioning, but this knowledge base has not been systematically integrated to date. This review coalesces the burgeoning body of mindfulness scholarship into a framework to guide mainstream management research investigating a broad range of constructs. The framework identifies how mindfulness influences attention, with downstream effects on functional domains of cognition, emotion, behavior, and physiology. Ultimately, these domains impact key workplace outcomes, including performance, relationships, and well-being. Consideration of the evidence on mindfulness at work stimulates important questions and challenges key assumptions within management science, generating an agenda for future research
Edmonton Obesity Staging System Prevalence and Association with Weight Loss in a Publicly Funded Referral-Based Obesity Clinic
Objectives. To determine the distribution of EOSS stages and differences in weight loss achieved according to EOSS stage, in patients attending a referral-based publically funded multisite weight management clinic. Subjects/Methods. 5,787 obese patients were categorized using EOSS staging using metabolic risk factors, medication use, and severity of doctor diagnosis of obesity-related physiological, functional, and psychological comorbidities from electronic patient files. Results. The prevalence of EOSS stages 0 (no risk factors or comorbidities), 1 (mild conditions), 2 (moderate conditions), and 3 (severe conditions) was 1.7%, 10.4%, 84.0%, and 3.9%, respectively. Prehypertension (63%), hypertension (76%), and knee replacement (33%) were the most common obesity-related comorbidities for stages 1, 2, and 3, respectively. In the models including age, sex, initial BMI, EOSS stage, and treatment time, lower EOSS stage and longer treatment times were independently associated with greater absolute (kg) and percentage of weight loss relative to initial body weight P<0.05. Conclusions. Patients attending this publicly funded, referral-based weight management clinic were more likely to be classified in the higher stages of EOSS. Patients in higher EOSS stages required longer treatment times to achieve similar weight outcomes as those in lower EOSS stages
Customising Best Practice In Studies Advice For Undergraduate Engineering Students
The attrition rates from undergraduate engineering programmes in the UK remains stubbornly high, despite the best efforts of course teams to engage and support students on their learning journeys. It is generally accepted that there is no single reason for attrition rates from engineering programmes being higher than from other vocational-type university programmes, but many academics believe that an effective Studies Advice system that works for students and staff, could lead to reduced numbers of disengaging and/or failing students. Much has been written on effective approaches to the provision of Studies Advice at University, but it is not clear if the implementation of discipline specific approaches would yield better outcomes. This practice paper describes work that is currently underway at Ulster University to examine engineering students’ perspectives on the Studies Advice approach and to explore how best practice in the university sector might be effectively customised for engineering students. The work describes an initial scoping study, a co-creation exercise with students to establish their baseline understanding of the current system and their ‘wish-list’, and a follow-up focus group session where a number of discipline-specific interventions were explored. Preliminary findings indicate that professional support departments could be more effectively integrated with academic support to provide a wrap-around or ‘single contact point’ for Studies Advice, that formal organised studies advice sessions should be explicit on programme schedules and that an informal ‘buddy or mentor’ student-to-student support system would be beneficial in addressing the UK engineering student attrition issue
Hurting and healing in therapeutic environments: how can we understand the role of the relational context?
It has long been recognized that relationships are key to good mental health service delivery and yet the quality of the relational context remains poorly understood. This article brings together three studies that utilize very different methodologies to explore the various ways in which a process of therapeutic change can be aided or prevented by relational factors. All three studies took place within the context of therapeutic communities. The first study uses narrative ethnography and interaction ritual theory to explain how the mechanisms of everyday encounters in two therapeutic communities transform negative feeling into a sense of belonging and positive emotions such as confidence. The second study uses grounded theory to explore how the relational setting and the altered context of the researcher in a therapeutic faith community environment induces either a positive or negative quality of relationships. The final study uses a novel autoethnographic methodology to inform understanding of the relational experience of mental health treatment by comparing and contrasting multiple perspectives of different treatment environments. The paper concludes by identifying the expression and containment of affect in a congruent environment, belonging and hope, and fluid hierarchies of relational structures as key aspects of the relational context informing change
IL-1 receptor like 1 protects against alcoholic liver injury by limiting NF-κB activation in hepatic macrophages
Background & Aim
Alcohol consumption increases intestinal permeability and causes damage to hepatocytes, leading to the release of pathogen- and damage-associated molecular pattern molecules (PAMPs and DAMPs), stimulating hepatic macrophages and activating NF-κB. The resultant inflammation exacerbates alcoholic liver disease (ALD). However, much less is known about the mechanisms attenuating inflammation and preventing disease progression in most heavy drinkers. Interleukin (IL)-33 is a DAMP (alarmin) released from dead cells that acts through its receptor, IL-1 receptor like 1 (ST2). ST2 signaling has been reported to either stimulate or inhibit NF-κB activation. The role of IL-33/ST2 in ALD has not been studied.
Methods
Serum levels of IL-33 and its decoy receptor, soluble ST2 (sST2) were measured in ALD patients. Alcohol-induced liver injury, inflammation and hepatic macrophage activation were compared between wild-type, IL-33−/− and ST2−/− mice in several models.
Results
Elevation of serum IL-33 and sST2 were only observed in patients with severe decompensated ALD. Consistently, in mice with mild ALD without significant cell death and IL-33 release, IL-33 deletion did not affect alcohol-induced liver damage. However, ST2-deletion exacerbated ALD, through enhancing NF-κB activation in liver macrophages. In contrast, when extracellular IL-33 was markedly elevated, liver injury and inflammation were attenuated in both IL-33−/− and ST2−/− mice compared to wild-type mice.
Conclusion
Our data revealed a dichotomous role of IL-33/ST2 signaling during ALD development. At early and mild stages, ST2 restrains the inflammatory activation of hepatic macrophages, through inhibiting NF-κB, and plays a protective function in an IL-33-independent fashion. During severe liver injury, significant cell death and marked IL-33 release occur, which triggers IL-33/ST2 signaling and exacerbates tissue damage.
Lay summary
In mild ALD, ST2 negatively regulates the inflammatory activation of hepatic macrophages, thereby protecting against alcohol-induced liver damage, whereas in the case of severe liver injury, the release of extracellular IL-33 may exacerbate tissue inflammation by triggering the canonical IL-33/ST2L signaling in hepatic macrophages
Longitudinal genomic surveillance of MRSA in the UK reveals transmission patterns in hospitals and the community.
Genome sequencing has provided snapshots of the transmission of methicillin-resistant Staphylococcus aureus (MRSA) during suspected outbreaks in isolated hospital wards. Scale-up to populations is now required to establish the full potential of this technology for surveillance. We prospectively identified all individuals over a 12-month period who had at least one MRSA-positive sample processed by a routine diagnostic microbiology laboratory in the East of England, which received samples from three hospitals and 75 general practitioner (GP) practices. We sequenced at least 1 MRSA isolate from 1465 individuals (2282 MRSA isolates) and recorded epidemiological data. An integrated epidemiological and phylogenetic analysis revealed 173 transmission clusters containing between 2 and 44 cases and involving 598 people (40.8%). Of these, 118 clusters (371 people) involved hospital contacts alone, 27 clusters (72 people) involved community contacts alone, and 28 clusters (157 people) had both types of contact. Community- and hospital-associated MRSA lineages were equally capable of transmission in the community, with instances of spread in households, long-term care facilities, and GP practices. Our study provides a comprehensive picture of MRSA transmission in a sampled population of 1465 people and suggests the need to review existing infection control policy and practice
Lessons Learned from Testing the Quality Cost Model of Advanced Practice Nursing (APN) Transitional Care
Purpose To describe the development, testing, modification, and results of the Quality Cost Model of Advanced Practice Nurses (APNs) Transitional Care on patient outcomes and health care costs in the United States over 22 years, and to delineate what has been learned for nursing education, practice, and further research. Organizing Construct The Quality Cost Model of APN Transitional Care. Methods Review of published results of seven randomized clinical trials with very low birth-weight (VLBW) infants; women with unplanned cesarean births, high risk pregnancies, and hysterectomy surgery; elders with cardiac medical and surgical diagnoses and common diagnostic related groups (DRGs); and women with high risk pregnancies in which half of physician prenatal care was substituted with APN care. Ongoing work with the model is linking the process of APN care with the outcomes and costs of care. Findings APN intervention has consistently resulted in improved patient outcomes and reduced health care costs across groups. Groups with APN providers were rehospitalized for less time at less cost, reflecting early detection and intervention. Optimal number and timing of postdischarge home visits and telephone contacts by the APNs and patterns of rehospitalizations and acute care visits varied by group. Conclusions To keep people well over time, APNs must have depth of knowledge and excellent clinical and interpersonal skills that are the hallmark of specialist practice, an in-depth understanding of systems and how to work within them, and sufficient patient contact to effect positive outcomes at low cost
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