296 research outputs found
A complex speciation-richness relationship in a simple neutral model
Speciation is the "elephant in the room" of community ecology. As the
ultimate source of biodiversity, its integration in ecology's theoretical
corpus is necessary to understand community assembly. Yet, speciation is often
completely ignored or stripped of its spatial dimension. Recent approaches
based on network theory have allowed ecologists to effectively model complex
landscapes. In this study, we use this framework to model allopatric and
parapatric speciation in networks of communities and focus on the relationship
between speciation, richness, and the spatial structure of communities. We find
a strong opposition between speciation and local richness, with speciation
being more common in isolated communities and local richness being higher in
more connected communities. Unlike previous models, we also find a transition
to a positive relationship between speciation and local richness when dispersal
is low and the number of communities is small. Also, we use several measures of
centrality to characterize the effect of network structure on diversity. The
degree, the simplest measure of centrality, is found to be the best predictor
of local richness and speciation, although it loses some of its predictive
power as connectivity grows. Our framework shows how a simple neutral model can
be combined with network theory to reveal complex relationships between
speciation, richness, and the spatial organization of populations.Comment: 9 pages, 5 figures, 1 table, 50 reference
Athletes’ Relationships with Training Scale (ART)
The Athletes’ Relationships with Training Scale (ART)* is a self-report measure of unhealthy training behaviors and beliefs in athletes. The ART was designed for use by clinicians and athletic trainers to help identify athletes who are engaging in unhealthy training practices which could be associated with an eating disorder. The ART may also be helpful for tracking clinical outcomes in athletes with eating disorders who are receiving treatment. This record contains the 15-item ART as well as scoring instructions and guidelines for interpreting total scores
Employment and ability to work after kidney transplantation in the Netherlands:The impact of preemptive versus non-preemptive kidney transplantation
Background: Work can have a major positive impact on health and wellbeing. Employment of kidney transplant recipients (KTR) of working age is much lower than in the general population. The first aim of this study was to examine the impact of a preemptive kidney transplantation (PKT) on employment, in addition to other possible influencing factors. The second aim was to explore differences in work ability, absenteeism and work performance among employed KTR with different types of transplantations. Methods: A cross-sectional survey study was conducted between 2018 and 2019 in nine Dutch hospitals. PKT as potential predictor of employment was examined. Furthermore, work ability, absenteeism and loss of work performance were compared between employed preemptive recipients with a living donor (L-PKT) and non-preemptive recipients with a living donor (L-nPKT) and with a deceased donor (D-nPKT). Results: Two hundred and twenty four KTR participated; 71% reported having paid work. Paid work was more common among PKT recipients (82% vs. 65% in L-nPKT and 55% in D-nPKT) and recipients who were younger (OR .950, 95%CI .913-.989), had no comorbidities (1 comorbidity: OR .397, 95%CI .167-.942; 2 comorbidities: OR .347, 95%CI .142-.844), had less fatigue (OR .974, 95%CI .962-.987) and had mentally demanding work tasks (only in comparison with physically demanding tasks, OR .342, 95%CI .145-.806). If recipients were employed, D-nPKT recipients worked fewer hours (mean 24.6 +/- 11.3 vs. PKT 31.1 +/- 9.6, L-nPKT 30.1 +/- 9.5) and D-nPKT and L-nPKT recipients received more often supplemental disability benefits (32 and 33.3%, respectively) compared to PKT recipients (9.9%). No differences were found for self-reported ability to work, sick leave (absenteeism) and loss of work performance with the exception of limitations in functioning at work. Conclusions: Preemptive kidney transplantation recipients with a kidney from a living donor are employed more often, work more hours per week (only in comparison with D-nPKT) and have a partial disability benefit less often than nPKT recipients. More knowledge regarding treatments supporting sustainable participation in the labor force is needed as work has a positive impact on recipients' health and wellbeing and is also beneficial for society as a whole
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Single-cell RNA-seq reveals novel regulators of human embryonic stem cell differentiation to definitive endoderm
Background: Human pluripotent stem cells offer the best available model to study the underlying cellular and molecular mechanisms of human embryonic lineage specification. However, it is not fully understood how individual stem cells exit the pluripotent state and transition towards their respective progenitor states. Results: Here, we analyze the transcriptomes of human embryonic stem cell-derived lineage-specific progenitors by single-cell RNA-sequencing (scRNA-seq). We identify a definitive endoderm (DE) transcriptomic signature that leads us to pinpoint a critical time window when DE differentiation is enhanced by hypoxia. The molecular mechanisms governing the emergence of DE are further examined by time course scRNA-seq experiments, employing two new statistical tools to identify stage-specific genes over time (SCPattern) and to reconstruct the differentiation trajectory from the pluripotent state through mesendoderm to DE (Wave-Crest). Importantly, presumptive DE cells can be detected during the transitory phase from Brachyury (T)+ mesendoderm toward a CXCR4+ DE state. Novel regulators are identified within this time window and are functionally validated on a screening platform with a T-2A-EGFP knock-in reporter engineered by CRISPR/Cas9. Through loss-of-function and gain-of-function experiments, we demonstrate that KLF8 plays a pivotal role modulating mesendoderm to DE differentiation. Conclusions: We report the analysis of 1776 cells by scRNA-seq covering distinct human embryonic stem cell-derived progenitor states. By reconstructing a differentiation trajectory at single-cell resolution, novel regulators of the mesendoderm transition to DE are elucidated and validated. Our strategy of combining single-cell analysis and genetic approaches can be applied to uncover novel regulators governing cell fate decisions in a variety of systems. Electronic supplementary material The online version of this article (doi:10.1186/s13059-016-1033-x) contains supplementary material, which is available to authorized users
Acrolein Induces Endoplasmic Reticulum Stress and Causes Airspace Enlargement
BACKGROUND: Given the relative abundance and toxic potential of acrolein in inhaled cigarette smoke, it is surprising how little is known about the pulmonary and systemic effects of acrolein. Here we test the hypothesis whether systemic administration of acrolein could cause endoplasmic reticulum (ER) stress, and lung cell apoptosis, leading to the enlargement of the alveolar air spaces in rats. METHODS: Acute and chronic effects of intraperitoneally administered acrolein were tested. Mean alveolar airspace area was measured by using light microscopy and imaging system software. TUNEL staining and immunohistochemistry (IHC) for active caspase 3 and Western blot analysis for active caspase 3, and caspase 12 were performed to detect apoptosis. The ER-stress related gene expression in the lungs was determined by Quantitative real-time PCR analysis. Acrolein-protein adducts in the lung tissue were detected by IHC. RESULTS: Acute administration of acrolein caused a significant elevation of activated caspase 3, upregulation of VEGF expression and induced ER stress proteins in the lung tissue. The chronic administration of acrolein in rats led to emphysematous lung tissue remodeling. TUNEL staining and IHC for cleaved caspase 3 showed a large number of apoptotic septal cells in the acrolein-treated rat lungs. Chronic acrolein administration cause the endoplasmic reticulum stress response manifested by significant upregulation of ATF4, CHOP and GADd34 expression. In smokers with COPD there was a considerable accumulation of acrolein-protein adducts in the inflammatory, airway and vascular cells. CONCLUSIONS: Systemic administration of acrolein causes endoplasmic reticulum stress response, lung cell apoptosis, and chronic administration leads to the enlargement of the alveolar air spaces and emphysema in rats. The substantial accumulation of acrolein-protein adducts in the lungs of COPD patients suggest a role of acrolein in the pathogenesis of emphysema
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Spring 1959
Seed testing - A Service for You by Miss Jessie L. Anderson (page 1) Increased Interest in Two-Year Turf Course by Fred P. Jeffrey - Director of Stockbridge (4) From the Editor (4) Message From Winter School President of 1959 (5) Turf club News (6) Number One Graduate (8) Liquid Fertilization by A.B. Longo (9) Public School Grounds by James Woodhouse (12) Comments on the 1959 Winter School (14) Picture - Stockbridge Turf Majors (16) Picture - Honorary Members of Turf Management Club (17) Letter on Chemical Compatibility (18) The Most Outstanding Turf Senior for 1958 (19) What it Means to be a Turf Manager by R. Russell (20) 10 Steps to a Better Lawn by P. Pedrazzi (24) A Scene to Remember (25) I switched from Hots to Cools by J. Spodnik (26) Why Attend Turfgrass Conferences (27) Picture - Winter School for Turf Managers - 1959 (29) Picture - University of Masssachusetts Annual Turfgrass Conference (30) Organic Fertilizers by O.J. Noer (A-1) Inorganic Fertilizers by Charles Winchell (A-1) Urea Formaldehyde by G.F. Stewart (A-2) Phosphorus and Potash Fertilization by Raph Donaldson (A-3) Questions on Fertilization to the Panel (A-4) Cemetery Maintenance by S.E. Robbins (A-6) Lime by Anson Brewer (A-6) Limited Budgets by R.W. Sharkey (A-7) Fertilization of Park Turf by E.J. Pyle (A-7) Disease and Insect Control by Orlando Capizzi (A-8) Cost of Establishing Turf by Victor Taricano (A-9) Question and Answers (A-10) Control of Pests of Ornamentals and Turf Occuring on Golf Courses by John C. Schread (A-12) Behind the Scenes in Soil Testing and What it Means to You Bertram Gersten and Wm. G. Colby (A-19) Lessons Learned from the 1958 Season as Applied to Golf Course Maintenance by A.M. Radko (A-21) The Outlook in Chemical Weed Control on Fine Turf by John Gallagher (A-24) New Developments in Turfgrass Disease Diagnosis and Control by Frank Howard (A-26
Cardiac Sarcoidosis: When and How to Treat Inflammation
Sarcoidosis is a complex, multisystem inflammatory disease with a heterogeneous clinical spectrum. Approximately 25% of patients with systemic sarcoidosis will have cardiac involvement that portends a poorer outcome. The diagnosis, particularly of isolated cardiac sarcoidosis, can be challenging. A paucity of randomised data exist on who, when and how to treat myocardial inflammation in cardiac sarcoidosis. Despite this, corticosteroids continue to be the mainstay of therapy for the inflammatory phase, with an evolving role for steroid-sparing and biological agents. This review explores the immunopathogenesis of inflammation in sarcoidosis, current evidence-based treatment indications and commonly used immunosuppression agents. It explores a multidisciplinary treatment and monitoring approach to myocardial inflammation and outlines current gaps in our understanding of this condition, emerging research and future directions in this field
A Multi-Wavelength Perspective of Flares on HR 1099: Four Years of Coordinated Campaigns
We report on four years of multiple wavelength observations of the RS CVn
system V711 Tau (HR 1099) from 1993, 1994, 1996, and 1998. This combination of
radio, ultraviolet, extreme ultraviolet, and X-ray observations allows us to
view, in the most comprehensive manner currently possible, the coronal and
upper atmospheric variability of this active binary system. We report on the
changing activity state of the system as recorded in the EUV and radio across
the four years of the observations, and study the high energy variability using
an assemblage of X-ray telescopes. (Longer abstract in paper).Comment: manuscript is 110 pages in length; 36 figures tota
Mineralogy and petrology of comet 81P/wild 2 nucleus samples
The bulk of the comet 81P/Wild 2 (hereafter Wild 2) samples returned to Earth by the Stardust spacecraft appear to be weakly constructed mixtures of nanometer-scale grains, with occasional much larger (over 1 micrometer) ferromagnesian silicates, Fe-Ni sulfides, Fe-Ni metal, and accessory phases. The very wide range of olivine and low-Ca pyroxene compositions in comet Wild 2 requires a wide range of formation conditions, probably reflecting very different formation locations in the protoplanetary disk. The restricted compositional ranges of Fe-Ni sulfides, the wide range for silicates, and the absence of hydrous phases indicate that comet Wild 2 experienced little or no aqueous alteration. Less abundant Wild 2 materials include a refractory particle, whose presence appears to require radial transport in the early protoplanetary disk
RANTES/CCL5 and risk for coronary events: Results from the MONICA/KORA Augsburg case-cohort, Athero-express and CARDIoGRAM studies
Background: The chemokine RANTES (regulated on activation, normal T-cell expressed and secreted)/CCL5 is involved in the pathogenesis of cardiovascular disease in mice, whereas less is known in humans. We hypothesised that its relevance for atherosclerosis should be reflected by associations between CCL5 gene variants, RANTES serum concentrations and protein levels in atherosclerotic plaques and risk for coronary events. Methods and Findings: We conducted a case-cohort study within the population-based MONICA/KORA Augsburg studies. Baseline RANTES serum levels were measured in 363 individuals with incident coronary events and 1,908 non-cases (mean follow-up: 10.2±
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