1,118 research outputs found

    Climate and the autumnal moth (Epirrita autumnata) at Mountain Birch (Betula pubecens ssp. czerepanovii) Treelines in northern Sweden.

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    The main objectives of this investigation were to determine the impact of climate on mountain birch (Betula pubecens ssp. czerepanovii (Orlova)) growth and to develop a regional chronology of autumnal moth outbreaks. To accomplish the objective, cores of mountain birch were taken from 21 sites in Norrbotten, Sweden. Tree-ring chronologies were developed for each site. Climatic influences were determined by correlating ring widths to climatic variables (average monthly temperature, average monthly precipitation and NAO). Outbreaks were recovered from the ring width indices using the non-host method with Scots pine (Pinus sylvestris (L.)) as the non-host. This method removes the climatic influence on growth to enhance other factors. Patterns of synchrony and regional outbreaks were detected using regression and cluster analysis techniques. The primary climatic influences on the tree ring growth of mountain birch are June and July temperatures; precipitation during October is of secondary importance. Climate explained 46% of yearly tree ring width variation. Outbreaks of the autumnal moth occur at varying time intervals depending on the scale of study. Intervals between outbreaks on the tree level are twice as long as at the plot level. On the regional scale plots within the same valley had more similar outbreak intervals and magnitudes of outbreaks. Elevation is a driver in determining the length of outbreaks and length between outbreaks. The percent monocormicity of a plot is also a determining factor of the length between outbreaks. This study is the first regional scale study on climate and outbreaks of the autumnal moth on mountain birch. The results complement research being conducted on autumnal moth larval densities and will help in modeling and assessing the effects of outbreaks with increasing climatic change

    The Heart Failure Overweight/Obesity Survival Paradox : The Missing Sex Link

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    Objectives: This study sought to determine whether body mass index (BMI) has a differential impact on survival for females versus males with advanced systolic heart failure (HF). Background: Females have a survival advantage in HF, the mechanisms of which are unclear. There is also a proposed “obesity survival paradox” in which excess adiposity promotes HF survival. Methods: We reviewed 3,811 patients with left ventricular ejection fraction ≀40% who had undergone cardiopulmonary exercise testing between 1995 and 2011. The endpoint was all-cause mortality. Multivariable analysis was performed using a Cox proportional hazards model. Because of the nonlinearity of BMI, a restricted cubic spline was used. An interaction term was added to investigate the impact of BMI on mortality by sex. Results: The unadjusted data demonstrated an overall obesity survival paradox in HF. This survival paradox disappeared for males after adjustment for potential confounders, with overweight and obese males showing higher adjusted mortality hazard ratios compared with normal weight males. Conversely, females in the overweight BMI range (25.0 to 29.9 kg/m2) had the lowest adjusted mortality (hazard ratio: 0.84; 95% confidence interval: 0.77 to 0.93; p = 0.0005 compared with normal weight females) with a nadir in mortality hazard just below BMI 30 kg/m2. The multivariable model supported a differential impact of BMI on mortality in males versus females (p for interaction \u3c0.0001). Conclusions: In this advanced HF cohort, an unadjusted obesity survival paradox disappeared after adjustment for confounders. Overweight and obese males had higher adjusted mortality than normal weight males, whereas a BMI in the overweight range was associated with a significant survival benefit in females

    Dendrochronological dating of coal mine workings at the Joggins Fossil Cliffs, Nova Scotia, Canada

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    Joggins, Nova Scotia was one of the first places in North America where coal was mined. In this paper we employ dendrochronology to date timber pit props preserved within relic coal mine workings on the closely adjacent Fundy and Dirty seams. These remains comprise a system of adits created through ‘room and pillar’ mining. Of the seventy-three samples collected, forty-eight were successfully cross-dated against a local red spruce (Picea rubens Sarg.) master chronology thereby establishing the year in which each individual sample was cut as a live tree. Results indicate cut dates of 1849-1875 which are generally consistent with written archival records of mining activity on these coal seams. Our analysis of fourteen separate adits allows us to distinguish two phases of mining. Most adits (numbers 1-9 and 11-12 with cut dates of 1849-1868) are relics of an initial operation by the General Mining Association (1865-1871), which opened a mine entered at beach level. Dendrochronological dates preceding the opening of this mine may suggest that timber stockpiled from the nearby Joggins Mine (opened 1847) was used in its construction. The remaining adits (numbers 10 and 13-14 with cut dates of 1873-1875) are probably relics of a later mine opened by the Joggins Coal Mining Company (1872-1877). Although this mine was centered ~500 m inland, its western peripheral workings passed through the earlier workings to the shore. Findings improve knowledge of the industrial archaeology of the UNESCO World Heritage Site and help refine the regional master red spruce chronology for future dendrochronological studies

    Weight Status: A Predictor of the Receipt of and Interest in Health Promotion Information among College Students

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    Background: Negative health behaviors such as consumption of excess calories, low intake of fruits and vegetables, sedentariness and weight gain are associated with entry into college. Purpose: To determine if weight status is associated with students’ receipt of health promotion (nutrition, physical activity and stress reduction) information, and students’ interest in receiving these types of information from their college or university. Methods: Data from the Spring 2011 ACHA-NCHA II dataset was used to complete secondary data analyses. Students (N=116,254) from 148 postsecondary institutions completed the Spring 2011 ACHA-NCHA II survey. Logistic regression was used to examine the effect of BMI category on receipt of, and interest in receiving, health promotion information. Results: Approximately 32% of respondents were overweight or obese. Students in the obese class III category were the least likely to receive health promotion information and least likely to be interested in receiving the information. Conclusion: Weight status based on BMI classification is a weak predictor of the dissemination of health promotion information. The largest gaps related to the dissemination appear to be among obese students. Future research is needed to determine factors contributing to the observed gaps and strategies should be developed to reach underserved groups

    What happens before, during and after crisis for someone with dementia living at home: a systematic review

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    Background People living with dementia often experience crisis. Home treatment of crisis is an alternative to hospital admission that can have better outcomes. This systematic review is about people with dementia living at home and in crisis. It identifies modifiable factors in the crisis process that may facilitate crisis resolution. Methods The protocol is registered on PROSPERO. A systematic search of MEDLINE, EMBASE, CINAHL, AHMED, PsycINFO, Cochrane Library and references of retrieved publications, identified empirical research in English language and date range January 2000 to February 2019. Two researchers independently screened abstracts, selected publications and extracted data using a framework based on published guidelines. This is a report of the analysis and narrative synthesis. Results The search identified 2755 titles and abstracts, 76 were selected for full-text examination and 13 agreed for inclusion. The included studies evidence that: for a person with dementia, crisis is a process that begins with a problem judged to put them or others at risk of harm. It leads to decision and action to treat this risk, thus resolve the crisis. Such crisis can be predicted or unpredicted and progress quickly or slowly. Medical treatment, community resources and psychosocial support of personal resources, decision making, relationships and social networks, are all modifiable factors that can treat the risk of harm during crisis. Carers’ and professionals’ knowledge and skills in dementia care are likely to play a key role in crisis resolution in the home. Conclusion There has been limited investigation of the process and management of crisis at home for people living with dementia. The results of this review provide a foundation for future research. There is no consensus on critical components of home treatment to facilitate crisis resolution. However, education in dementia care for carers and professionals is likely to prove essential to successful home treatment

    Study protocol: NITric oxide during cardiopulmonary bypass to improve Recovery in Infants with Congenital heart defects (NITRIC trial): a randomised controlled trial

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    Introduction Congenital heart disease (CHD) is a major cause of infant mortality. Many infants with CHD require corrective surgery with most operations requiring cardiopulmonary bypass (CPB). CPB triggers a systemic inflammatory response which is associated with low cardiac output syndrome (LCOS), postoperative morbidity and mortality. Delivery of nitric oxide (NO) into CPB circuits can provide myocardial protection and reduce bypass-induced inflammation, leading to less LCOS and improved recovery. We hypothesised that using NO during CPB increases ventilator-free days (VFD) (the number of days patients spend alive and free from invasive mechanical ventilation up until day 28) compared with standard care. Here, we describe the NITRIC trial protocol. Methods and analysis The NITRIC trial is a randomised, double-blind, controlled, parallel-group, two-sided superiority trial to be conducted in six paediatric cardiac surgical centres. One thousand three-hundred and twenty infants <2 years of age undergoing cardiac surgery with CPB will be randomly assigned to NO at 20 ppm administered into the CPB oxygenator for the duration of CPB or standard care (no NO) in a 1:1 ratio with stratification by age (<6 and ≄6 weeks), single ventricle physiology (Y/N) and study centre. The primary outcome will be VFD to day 28. Secondary outcomes include a composite of LCOS, need for extracorporeal membrane oxygenation or death within 28 days of surgery; length of stay in intensive care and in hospital; and, healthcare costs. Analyses will be conducted on an intention-to-treat basis. Preplanned secondary analyses will investigate the impact of NO on host inflammatory profiles postsurgery. Ethics and dissemination The study has ethical approval (HREC/17/QRCH/43, dated 26 April 2017), is registered in the Australian New Zealand Clinical Trials Registry (ACTRN12617000821392) and commenced recruitment in July 2017. The primary manuscript will be submitted for publication in a peer-reviewed journal. Trial registration number ACTRN12617000821392.</p

    Induced ectopic expression of HigB toxin in Mycobacterium tuberculosis results in growth inhibition, reduced abundance of a subset of mRNAs and cleavage of tmRNA.

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    In Mycobacterium tuberculosis, the genes Rv1954A-Rv1957 form an operon that includes Rv1955 and Rv1956 which encode the HigB toxin and the HigA antitoxin respectively. We are interested in the role and regulation of this operon, since toxin-antitoxin systems have been suggested to play a part in the formation of persister cells in mycobacteria. To investigate the function of the higBA locus, effects of toxin expression on mycobacterial growth and transcript levels were assessed in M. tuberculosis H37Rv wild type and in an operon deletion background. We show that expression of HigB toxin in the absence of HigA antitoxin arrests growth and causes cell death in M. tuberculosis. We demonstrate HigB expression to reduce the abundance of IdeR and Zur regulated mRNAs and to cleave tmRNA in M. tuberculosis, Escherichia coli and Mycobacterium smegmatis. This study provides the first identification of possible target transcripts of HigB in M. tuberculosis

    Does patient-provider race/ethnicity concordance impact outcomes for adults with lupus?

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    Background: Health disparities exist among the 1.5 million Americans with lupus, with women of color bearing higher disease rates and burden. Complex reasons include genetics, comorbidities, and socioeconomics. These factors may lead to differences in health-related outcomes in lupus. Aim: To determine if patient-provider racial/ethnic concordance plays a role in outcomes for adults with lupus. Method: For this scoping review, the authors searched PubMed Medline and CINAHL using keywords and subject headings for lupus, race or ethnicity, and patient-health professional concordance. Results: Despite an intentionally broadened search of literature, the authors identified a lack of studies examining the topic. Conclusions: Certain factors may explain the results: a lack of scientists studying the phenomenon, a focus of funding on bench science, and a non-diverse U.S. healthcare provider workforce. Other factors may exist. Implications for practice, policy, and research are presented

    A microphysiological system model of therapy for liver micrometastases

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    Metastasis accounts for almost 90% of cancer-associated mortality. The effectiveness of cancer therapeutics is limited by the protective microenvironment of the metastatic niche and consequently these disseminated tumors remain incurable. Metastatic disease progression continues to be poorly understood due to the lack of appropriate model systems. To address this gap in understanding, we propose an all-human microphysiological system that facilitates the investigation of cancer behavior in the liver metastatic niche. This existing LiverChip is a 3D-system modeling the hepatic niche; it incorporates a full complement of human parenchymal and non-parenchymal cells and effectively recapitulates micrometastases. Moreover, this system allows real-time monitoring of micrometastasis and assessment of human-specific signaling. It is being utilized to further our understanding of the efficacy of chemotherapeutics by examining the activity of established and novel agents on micrometastases under conditions replicating diurnal variations in hormones, nutrients and mild inflammatory states using programmable microdispensers. These inputs affect the cues that govern tumor cell responses. Three critical signaling groups are targeted: the glucose/insulin responses, the stress hormone cortisol and the gut microbiome in relation to inflammatory cues. Currently, the system sustains functioning hepatocytes for a minimum of 15 days; confirmed by monitoring hepatic function (urea, α-1-antitrypsin, fibrinogen, and cytochrome P450) and injury (AST and ALT). Breast cancer cell lines effectively integrate into the hepatic niche without detectable disruption to tissue, and preliminary evidence suggests growth attenuation amongst a subpopulation of breast cancer cells. xMAP technology combined with systems biology modeling are also employed to evaluate cellular crosstalk and illustrate communication networks in the early microenvironment of micrometastases. This model is anticipated to identify new therapeutic strategies for metastasis by elucidating the paracrine effects between the hepatic and metastatic cells, while concurrently evaluating agent efficacy for metastasis, metabolism and tolerability.National Institutes of Health (U.S.) (Grant 1UH2TR000496-01)United States. Defense Advanced Research Projects Agency. Microphysiological Systems Program (W911NF-12-2-0039
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