869 research outputs found
Ten years of pulling: Ecosystem recovery after longâterm weed management in Garry oak savanna
Ecosystem restoration is the practice of assisting recovery in degraded ecological communities. The aims of restoration are typically broad, involving the reinstatement of composition, structure, function, and resilience to disturbances. One common restoration tactic in degraded urban systems is to control invasive species, relying on passive restoration for further ecosystemâlevel recovery. Here, we test whether this is an effective restoration strategy in Garry oak savanna, a highly threatened and ecologically important community in the North American Pacific Northwest. In urban savanna patches surrounding Victoria, British Columbia, community members have been actively removing aggressive invasive exotic species for over a decade. Based on vegetation surveys from 2007, we tested ecosystem changes in structure, composition, and resilience (i.e., functional redundancy and response diversity) across 10âyears of varied management levels. We expected higher levels of invasive species management would correspond with improvements to these ecosystem metrics. However, management explained little of the patterns found over the 10âyearâperiod. Woody encroachment was a complicated process of native and exotic invasion, while resilience and compositional changes were most closely tied with landscape connectivity. Thus, though invasive species management may prevent further degradation, active restoration strategies after removal are likely required for recovery of the ecosystem
Chasing the identification of ASCA Galactic Objects (ChIcAGO): An X-ray survey of unidentified sources in the galactic plane. I : Source sample and initial results
We present the Chasing the Identification of ASCA Galactic Objects (ChIcAGO) survey, which is designed to identify the unknown X-ray sources discovered during the ASCA Galactic Plane Survey (AGPS). Little is known about most of the AGPS sources, especially those that emit primarily in hard X-rays (2-10 keV) within the Fx 10-13 to 10-11 erg cm -2 s-1 X-ray flux range. In ChIcAGO, the subarcsecond localization capabilities of Chandra have been combined with a detailed multiwavelength follow-up program, with the ultimate goal of classifying the >100 unidentified sources in the AGPS. Overall to date, 93 unidentified AGPS sources have been observed with Chandra as part of the ChIcAGO survey. A total of 253 X-ray point sources have been detected in these Chandra observations within 3Ⲡof the original ASCA positions. We have identified infrared and optical counterparts to the majority of these sources, using both new observations and catalogs from existing Galactic plane surveys. X-ray and infrared population statistics for the X-ray point sources detected in the Chandra observations reveal that the primary populations of Galactic plane X-ray sources that emit in the Fx 10-13 to 10-11 erg cm -2 s-1 flux range are active stellar coronae, massive stars with strong stellar winds that are possibly in colliding wind binaries, X-ray binaries, and magnetars. There is also another primary population that is still unidentified but, on the basis of its X-ray and infrared properties, likely comprises partly Galactic sources and partly active galactic nuclei.Peer reviewedSubmitted Versio
Are markers of inflammation more strongly associated with risk for fatal than for nonfatal vascular events?
<p><b>Background:</b> Circulating inflammatory markers may more strongly relate to risk of fatal versus nonfatal cardiovascular disease (CVD) events, but robust prospective evidence is lacking. We tested whether interleukin (IL)-6, C-reactive protein (CRP), and fibrinogen more strongly associate with fatal compared to nonfatal myocardial infarction (MI) and stroke.</p>
<p><b>Methods and Findings:</b> In the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER), baseline inflammatory markers in up to 5,680 men and women aged 70-82 y were related to risk for endpoints; nonfatal CVD (i.e., nonfatal MI and nonfatal stroke [n = 672]), fatal CVD (n = 190), death from other CV causes (n = 38), and non-CVD mortality (n = 300), over 3.2-y follow-up. Elevations in baseline IL-6 levels were significantly (p = 0.0009; competing risks model analysis) more strongly associated with fatal CVD (hazard ratio [HR] for 1 log unit increase in IL-6 1.75, 95% confidence interval [CI] 1.44-2.12) than with risk of nonfatal CVD (1.17, 95% CI 1.04-1.31), in analyses adjusted for treatment allocation. The findings were consistent in a fully adjusted model. These broad trends were similar for CRP and, to a lesser extent, for fibrinogen. The results were also similar in placebo and statin recipients (i.e., no interaction). The C-statistic for fatal CVD using traditional risk factors was significantly (+0.017; p<0.0001) improved by inclusion of IL-6 but not so for nonfatal CVD events (p = 0.20).</p>
<p><b>Conclusions:</b> In PROSPER, inflammatory markers, in particular IL-6 and CRP, are more strongly associated with risk of fatal vascular events than nonfatal vascular events. These novel observations may have important implications for better understanding aetiology of CVD mortality, and have potential clinical relevance.</p>
Anomalous diffusion with absorption: Exact time-dependent solutions
Recently, analytical solutions of a nonlinear Fokker-Planck equation
describing anomalous diffusion with an external linear force were found using a
non extensive thermostatistical Ansatz. We have extended these solutions to the
case when an homogeneous absorption process is also present. Some peculiar
aspects of the interrelation between the deterministic force, the nonlinear
diffusion and the absorption process are discussed.Comment: RevTex, 16 pgs, 4 figures. Accepted in Physical Review
The journey so far : professional sport during the COVID-19 pandemic
BACKGROUND : The COVID-19 pandemic has profoundly impacted community and professional sports. Throughout this time, sports organisations collaborated closely with the WHO, host national governments and their public health authorities. The common goals were to assess risk and to implement risk reduction measures to facilitate a stepwise return to sport, thus realising the physical and mental health benefits of sport for the participants, as well as the safe resumption of competitive events despite active SARS-CoV-2 transmission in many countries.https://bmjopensem.bmj.comSports Medicin
Comparison of methods for determination of nutrient digestibility of a dry kibble diet for ocelots
Optical Spectra of SNR Candidates in NGC 300
We present moderate-resolution (<5A) long-slit optical spectra of 51 nebular
objects in the nearby Sculptor Group galaxy NGC 300 obtained with the 2.3 meter
Advanced Technology Telescope at Siding Spring Observatory, Australia. Adopting
the criterion of [SII]/Ha>=0.4 to confirm supernova remnants (SNRs) from
optical spectra, we find that of 28 objects previously proposed as SNRs from
optical observations, 22 meet this criterion with six showing [SII]/Ha of less
than 0.4. Of 27 objects suggested as SNRs from radio data, four are associated
with the 28 previously proposed SNRs. Of these four, three (included in the 22
above) meet the criterion. In all, 22 of the 51 nebular objects meet the
[SII]/Ha criterion as SNRs while the nature of the remaining 29 objects remains
undetermined by these observations.Comment: Accepted for publication in Astrophysics & Space Scienc
Intermediate inflation in Gauss-Bonnet braneworld
In this article we study an intermediate inflationary universe models using
the Gauss-Bonnet brane. General conditions required for these models to be
realizable are derived and discussed. We use recent astronomical observations
to constraint the parameters appearing in the model.Comment: 16 pages, 2 figures, accepted for publication in European Physical
Journal
A combined microbial and biogeochemical dataset from high-latitude ecosystems with respect to methane cycle.
High latitudes are experiencing intense ecosystem changes with climate warming. The underlying
methane (CH4) cycling dynamics remain unresolved, despite its crucial climatic feedback. Atmospheric
CH4 emissions are heterogeneous, resulting from local geochemical drivers, global climatic factors,
and microbial production/consumption balance. Holistic studies are mandatory to capture CH4
cycling complexity. Here, we report a large set of integrated microbial and biogeochemical data from
387 samples, using a concerted sampling strategy and experimental protocols. The study followed
international standards to ensure inter-comparisons of data amongst three high-latitude regions:
Alaska, Siberia, and Patagonia. The dataset encompasses diferent representative environmental
features (e.g. lake, wetland, tundra, forest soil) of these high-latitude sites and their respective
heterogeneity (e.g. characteristic microtopographic patterns). The data included physicochemical
parameters, greenhouse gas concentrations and emissions, organic matter characterization, trace
elements and nutrients, isotopes, microbial quantifcation and composition. This dataset addresses
the need for a robust physicochemical framework to conduct and contextualize future research on
the interactions between climate change, biogeochemical cycles and microbial communities at highlatitudes
Reflections on IDEAL: What we have learnt from a unique calf cohort study
The year 2020 marks a decade since the final visit was made in the âInfectious Diseases of East African Livestockâ
(IDEAL) project. However, data generation from samples obtained during this ambitious longitudinal study still
continues. As the project launches its extensive open-access database and biobank to the scientific community,
we reflect on the challenges overcome, the knowledge gained, and the advantages of such a project. We discuss
the legacy of the IDEAL project and how it continues to generate evidence since being adopted by the Centre for
Tropical Livestock Genetics and Health (CTLGH). We also examine the impact of the IDEAL project, from the
authors perspective, for each of the stakeholders (the animal, the farmer, the consumer, the policy maker, the
funding body, and the researcher and their institution) involved in the project and provide recommendations for
future researchers who are interested in running longitudinal field studies.The Bill & Melinda Gates Foundation, the UK Governmentâs Department for International Development and the International Livestock Research Institute.http://www.elsevier.com/locate/prevetmedam2021Veterinary Tropical Disease
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