456 research outputs found

    Briefing Note: Community Forestry in Canada

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    Global economic instability, the need for local adaptation to climate change impacts, and Supreme Court rulings over Aboriginal and Treaty Rights have drawn attention to community dissatisfaction with centralized approaches to natural resource management. Communities across Canada seek opportunities for increased control over and benefits from natural resources

    Community forests Canada: Bridging practice, research and advocacy. A Symposium and Workshop Report.

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    The purpose of this report is to share experiences and observations from the Community Forests Canada joint workshop-symposium hosted by the Centre for Forest Interdisciplinary Research and Department of Environmental Studies and Sciences at The University of Winnipeg on June 25th and 26th, 2014. The new national network, Community Forests Canada, is committed to research, policy development, and advocacy for community forest initiatives. Stakeholders including researchers, Aboriginal representatives, government officials, local advocates, industry representatives, and students came together to exchange experiences and resources of significance to forest communities, industries, and ecosystems."The workshop and symposium were primarily supported by the Social Sciences and Humanities Research Council of Canada and The University of Winnipeg. Several other partners also made important cash and in-kind contributions....

    Arboretum Exchange, Fall 2019

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    The Arboretum Project, led by Professor Stan Braude of Biology, worked to certify the WashU campus as a Level II Arboretum. Students learned to identify and catalog trees, identified creative ways to engage the public with WU campus natural resources, and worked with Buildings & Grounds and the Office of Sustainability to plan for the future of tree initiatives on campus

    HD 209621: Abundances of neutron-capture elements

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    High resolution spectra obtained from the Subaru Telescope High Dispersion Spectrograph have been used to update the stellar atmospheric parameters and metallicity of the star HD 209621. We have derived a metallicity of [Fe/H] = -1.93 for this star, and have found a large enhancement of carbon and of heavy elements, with respect to iron. Updates on the elemental abundances of four s-process elements (Y, Ce, Pr, Nd) along with the first estimates of abundances for a number of other heavy elements (Sr, Zr, Ba, La, Sm, Eu, Er, Pb) are reported. The stellar atmospheric parameters, the effective temperature, Teff, and the surface gravity, log g (4500 K, 2.0), are determined from LTE analysis using model atmospheres. Estimated [Ba/Eu] = +0.35, places the star in the group of CEMP-(r+s) stars; however, the s-elements abundance pattern seen in HD 209621 is characteristic of CH stars; notably, the 2nd-peak s-process elements are more enhanced than the first peak s-process elements. HD 209621 is also found to show a large enhancement of the 3rd-peak s-process element lead (Pb) with [Pb/Fe] = +1.88. The relative contributions of the two neutron-capture processes, r- and s- to the observed abundances are examined using a parametric model based analysis, that hints that the neutron-capture elements in HD 209621 primarily originate in s-process.Comment: 16 pages,8 figures. Accepted for publication in MNRA

    Projecting the Hydrologic Impacts of Climate Change on Montane Wetlands

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    Wetlands are globally important ecosystems that provide critical services for natural communities and human society. Montane wetland ecosystems are expected to be among the most sensitive to changing climate, as their persistence depends on factors directly influenced by climate (e.g. precipitation, snowpack, evaporation). Despite their importance and climate sensitivity, wetlands tend to be understudied due to a lack of tools and data relative to what is available for other ecosystem types. Here, we develop and demonstrate a new method for projecting climate-induced hydrologic changes in montane wetlands. Using observed wetland water levels and soil moisture simulated by the physically based Variable Infiltration Capacity (VIC) hydrologic model, we developed site-specific regression models relating soil moisture to observed wetland water levels to simulate the hydrologic behavior of four types of montane wetlands (ephemeral, intermediate, perennial, permanent wetlands) in the U. S. Pacific Northwest. The hybrid models captured observed wetland dynamics in many cases, though were less robust in others. We then used these models to a) hindcast historical wetland behavior in response to observed climate variability (1916–2010 or later) and classify wetland types, and b) project the impacts of climate change on montane wetlands using global climate model scenarios for the 2040s and 2080s (A1B emissions scenario). These future projections show that climate-induced changes to key driving variables (reduced snowpack, higher evapotranspiration, extended summer drought) will result in earlier and faster drawdown in Pacific Northwest montane wetlands, leading to systematic reductions in water levels, shortened wetland hydroperiods, and increased probability of drying. Intermediate hydroperiod wetlands are projected to experience the greatest changes. For the 2080s scenario, widespread conversion of intermediate wetlands to fast-drying ephemeral wetlands will likely reduce wetland habitat availability for many species

    Nox2 Inhibition Regulates Stress Response and Mitigates Skeletal Muscle Fiber Atrophy during Simulated Microgravity

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    Insufficient stress response and elevated oxidative stress can contribute to skeletal muscle atrophy during mechanical unloading (e.g., spaceflight and bedrest). Perturbations in heat shock proteins (e.g., HSP70), antioxidant enzymes, and sarcolemmal neuronal nitric oxidase synthase (nNOS) have been linked to unloading-induced atrophy. We recently discovered that the sarcolemmal NADPH oxidase-2 complex (Nox2) is elevated during unloading, downstream of angiotensin II receptor 1, and concomitant with atrophy. Here, we hypothesized that peptidyl inhibition of Nox2 would attenuate disruption of HSP70, MnSOD, and sarcolemmal nNOS during unloading, and thus muscle fiber atrophy. F344 rats were divided into control (CON), hindlimb unloaded (HU), and hindlimb unloaded +7.5 mg/kg/day gp91ds-tat (HUG) groups. Unloading-induced elevation of the Nox2 subunit p67phox-positive staining was mitigated by gp91ds-tat. HSP70 protein abundance was significantly lower in HU muscles, but not HUG. MnSOD decreased with unloading; however, MnSOD was not rescued by gp91ds-tat. In contrast, Nox2 inhibition protected against unloading suppression of the antioxidant transcription factor Nrf2. nNOS bioactivity was reduced by HU, an effect abrogated by Nox2 inhibition. Unloading-induced soleus fiber atrophy was significantly attenuated by gp91ds-tat. These data establish a causal role for Nox2 in unloading-induced muscle atrophy, linked to preservation of HSP70, Nrf2, and sarcolemmal nNOS

    Cigarette smoking and e-cigarette use among university students in Queensland, Australia and New Zealand: results of two cross-sectional surveys

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    Objectives: Examine the patterns of cigarette smoking and e-cigarette use (vaping), the perceived harm of e-cigarettes compared with tobacco cigarettes, and associations between smoking and vaping with student characteristics. Design: Cross-sectional studies. Setting: The University of Queensland (UQ), Australia and eight New Zealand (NZ) universities. Participants: Students at UQ: 4957 (70.8% aged <25 years, 63.0% women) and NZ: 1854 (82.5% aged <25 years, 60.1% women). Methods: Χ2 tests compared smoking by age and gender, and vaping by age, gender and smoking status. Two-sided p<0.05 was considered significant and 95% CIs reported where appropriate. Multinomial logistic regression examined associations between smoking and vaping (exclusive smoking, exclusive vaping, dual use and non-use) with age, gender and student type (domestic vs international). Results: Smoking (UQ vs NZ, 95% CI): ever 45.2% (43.8% to 46.6%) vs 50.0% (47.7% to 52.3%), current 8.9% (8.1% to 9.7%) vs 10.4% (9.1% to 11.9%) and daily 5.2% (4.6% to 5.8%) vs 5.6% (4.6% to 6.7%), and not smoking in indoor 98.3% vs 87.7% or outdoor smoke-free spaces 83.8% vs 65.3%. Vaping (UQ vs NZ, 95% CI): ever 20.9% (19.8% to 22.1%) vs 37.6% (35.4% to 39.9%), current 1.8% (1.5% to 2.2%) vs 6.5% (5.4% to 7.7%) and daily 0.7% (0.5% to 1.0%) vs 2.5% (1.9% to 3.4%), and not vaping in indoor 91.4% vs 79.6% or outdoor smoke-free spaces 84.4% vs 71.3%. Of respondents, 71.7% (70.3% to 73.2%) vs 75.3% (72.9% to 77.6%) perceived e-cigarettes as less harmful than tobacco cigarettes. Men were more likely than women to smoke and vape, and to believe that e-cigarettes are less harmful. Regression models containing all predictors for smoking and vaping were significant and the effect of gender was significant for dual use, exclusive smoking and exclusive vaping (all p<0.01). Men had higher odds for smoking, vaping or dual use. Conclusions: Results suggest significant differences in patterns of smoking and vaping of university students in Australia and NZ, and a strong influence of gender on smoking and vaping

    Observations of Neutron-Capture Elements in the Early Galaxy

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    Neutron-capture elements in low metallicity Galactic halo stars vary widely both in overall contents and detailed abundance patterns. This review discusses recent observational results on the n-capture elements, discussing the implications for early Galactic nucleosynthesis of: (a) the star-to-star ``bulk'' variations in the n-capture/Fe abundance ratios; (b) the distinct signature of rapid n-capture synthesis events in many (most?) of the lowest metallicity stars; (c) the existence of metal-poor stars heavily enriched in the products of slow n-capture synthesis reactions; and (d) the now-routine detection of radioactive thorium (and even uranium in one and possibly two cases) in the spectra of metal-poor stars.Comment: 8 pages, 3 figures; To appear in the Proceedings of the 7th International Conference on Nuclei in the Cosmo

    A High-Resolution Atlas of Uranium-Neon in the H Band

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    We present a high-resolution (R ~ 50 000) atlas of a uranium-neon (U/Ne) hollow-cathode spectrum in the H-band (1454 nm to 1638 nm) for the calibration of near-infrared spectrographs. We obtained this U/Ne spectrum simultaneously with a laser-frequency comb spectrum, which we used to provide a first-order calibration to the U/Ne spectrum. We then calibrated the U/Ne spectrum using the recently-published uranium line list of Redman et al. (2011), which is derived from high-resolution Fourier transform spectrometer measurements. These two independent calibrations allowed us to easily identify emission lines in the hollow cathode lamp that do not correspond to known (classified) lines of either uranium or neon, and to compare the achievable precision of each source. Our frequency comb precision was limited by modal noise and detector effects, while the U/Ne precision was limited primarily by the signal-to-noise ratio (S/N) of the observed emission lines and our ability to model blended lines. The standard deviation in the dispersion solution residuals from the S/N-limited U/Ne hollow cathode lamp were 50% larger than the standard deviation of the dispersion solution residuals from the modal-noise-limited laser frequency comb. We advocate the use of U/Ne lamps for precision calibration of near-infrared spectrographs, and this H-band atlas makes these lamps significantly easier to use for wavelength calibration.Comment: 23 pages, 7 figures, submitted and accepted in ApJSS. Online-only material to be published online by ApJS
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