5,217 research outputs found
Monitoring Huckleberries for Invasive Fruit Flies and Climate Change Impacts on the Flathead Indian Reservation (Poster)
The huckleberry (Vaccinium spp.) has been important to both bears and the Salish people for hundreds of years. With predicted climate changes including increasing temperature, increasing variability in weather, and unknown changes in precipitation it is important to understand effects on huckleberry plants on the Flathead Reservation. In this project, we are proposing to extend huckleberry phenology research in Glacier National Park led by Dr. Tabitha Graves to the Flathead Reservation. The USGS project aims to understand potential climate change impacts on grizzly bear food sources, a research need identified in a workshop evaluating climate change impacts to grizzly bears (Servheen and Cross 2010). Two potential impacts include 1) changes in phenology that could impact pollination rates and thus productivity and 2) the possible presence of an invasive fruit fly, the spotted wing drosophila that lays eggs in ripe fruit, and can cause the fruit to drop off early. I will use remote cameras that record pictures every day to measure the length of time individual flowers bloom and individual berries are present. This will be used to evaluate how flowering time and duration and ripe berry time and duration varies with temperature across sites that range in precipitation and solar radiation. Productivity metrics will be recorded at the peak of the berry season. All findings and conclusions will be a part of my senior thesis and will be provided to the Confederated Salish and Kootenai Tribes
Prospects for Tin-Containing Halide Perovskite Photovoltaics
Tin-containing metal halide perovskites have enormous potential as photovoltaics, both in narrow band gap mixed tinâlead materials for all-perovskite tandems and for lead-free perovskites. The introduction of Sn(II), however, has significant effects on the solution chemistry, crystallization, defect states, and other material properties in halide perovskites. In this perspective, we summarize the main hurdles for tin-containing perovskites and highlight successful attempts made by the community to overcome them. We discuss important research directions for the development of these materials and propose some approaches to achieve a unified understanding of Sn incorporation. We particularly focus on the discussion of charge carrier dynamics and nonradiative losses at the interfaces between perovskite and charge extraction layers in p-i-n cells. We hope these insights will aid the community to accelerate the development of high-performance, stable single-junction tin-containing perovskite solar cells and all-perovskite tandems
World Vaping Day: Contextualizing Vaping Culture in Online Social Media Using a Mixed Methods Approach
Few studies have demonstrated the use of mixed methods research to contextualize health topics using primary data from social media. To address this gap in the methodological literature, we present research about electronic nicotine delivery systems, using Twitter data from âWorld Vaping Day.â To engage with the quantitative breadth and qualitative depth of 5,149 collected tweets, we utilized a convergent parallel mixed methods framework, integrating thematic prevalence estimates with phenomenological contextualization. Sentiment was more positive than negative across all categories except policy related. A total of 23% of tweets were promotional and relatively few tweets related to tobacco use (4.9%) or health concerns (4.2%). Salient themes included modifying or upgrading electronic nicotine delivery systems devices, and general mistrust of public health advocates and tobacco companies. </jats:p
Adapting to Climate Change: A Call for Federal Leadership
Recommends creating a strategic planning initiative to set goals, objectives, and priorities; a national climate service to provide information on climate change impacts and adaptation options; and an adaptation research program. Includes case summaries
Chimney Stove Intervention to Reduce Long-term Wood Smoke Exposure Lowers Blood Pressure among Guatemalan Women
Background and Objective: RESPIRE, a randomized trial of an improved cookstove, was conducted in Guatemala to assess health effects of long-term reductions in wood smoke exposure. Given the evidence that ambient particles increase blood pressure, we hypothesized that the intervention would lower blood pressure. Methods: Two study designs were used: a) between-group comparisons based on randomized stove assignment, and b) before-and-after comparisons within subjects before and after they received improved stoves. From 2003 to 2005, we measured personal fine particle (particulate matter with aerodynamic diameter 38 years of age from the chimney woodstove intervention group (49 subjects) and traditional open wood fire control group (71 subjects). Measures were repeated up to three occasions. Results: Daily average PM2.5 exposures were 264 and 102 ÎŒg/m3 in the control and intervention groups, respectively. After adjusting for age, body mass index, an asset index, smoking, secondhand tobacco smoke, apparent temperature, season, day of week, time of day, and a random subject intercept, the improved stove intervention was associated with 3.7 mm Hg lower SBP [95% confidence interval (CI), â8.1 to 0.6] and 3.0 mm Hg lower DBP (95% CI, â5.7 to â0.4) compared with controls. In the second study design, among 55 control subjects measured both before and after receiving chimney stoves, similar associations were observed. Conclusion: The between-group comparisons provide evidence, particularly for DBP, that the chimney stove reduces blood pressure, and the before-and-after comparisons are consistent with this evidence
Composite Accretion Disk and White Dwarf Photosphere Analyses of the FUSE and HST Observations of EY Cygni
We explore the origin of FUSE and HST STIS far UV spectra of the dwarf nova,
EY Cyg, during its quiescence using \emph{combined} high gravity photosphere
and accretion disk models as well as model accretion belts. The best-fitting
single temperature white dwarf model to the FUSE plus HST STIS spectrum of EY
Cygni has TK, log , with an Si abundance of 0.1 x
solar and C abundance of 0.2 x solar but the distance is only 301 pc. The
best-fitting composite model consists of white dwarf with TK,
log , plus an accretion belt with TK covering 27% of
the white dwarf surface with V km/s. The accretion belt
contributes 63% of the FUV light and the cooler white dwarf latitudes
contribute 37%. This fit yields a distance of 351 pc which is within 100 pc of
our adopted distance of 450 pc. EY Cyg has very weak C {\sc iv} emission and
very strong N {\sc v} emission, which is atypical of the majority of dwarf
novae in quiescence. We also conducted a morphological study of the
surroundings of EY Cyg using direct imaging in narrow nebular filters from
ground-based telescopes. We report the possible detection of nebular material^M
associated with EY Cygni. Possible origins of the apparently large N {\scv}/C
{\sc iv} emission ratio are discussed in the context of nova explosions,
contamination of the secondary star and accretion of nova abundance-enriched
matter back to the white dwarf via the accretion disk or as a descendant of a
precursor binary that survived thermal timescale mass transfer. The scenario
involving pollution of the secondary by past novae may be supported by the
possible presence of a nova remnant-like nebula around EY Cyg.Comment: To appear in AJ, Oct. 2004. 5 figures, including 2 color ones (2D
pictures
Does Obesity Cause Thyroid Cancer? A Mendelian Randomization Study
Background: The incidence of thyroid cancer is rising, and relatively little is known about modifiable risk factors for the condition. Observational studies have suggested a link between adiposity and thyroid cancer; however, these are subject to confounding and reverse causality. Here, we used data from the UK Biobank and Mendelian randomization approaches to investigate whether adiposity causes benign nodular thyroid disease and differentiated thyroid cancer.
Methods: We analyzed data from 379 708 unrelated participants of European ancestry in the UK Biobank and identified 1812 participants with benign nodular thyroid disease and 425 with differentiated thyroid carcinoma. We tested observational associations with measures of adiposity and type 2 diabetes mellitus. One and 2-sample Mendelian randomization approaches were used to investigate causal relationships.
Results: Observationally, there were positive associations between higher body mass index (odds ratio [OR], 1.15; 95% confidence interval [CI], 1.08-1.22), higher waist-hip ratio (OR, 1.16; 95% CI, 1.09-1.23), and benign nodular thyroid disease, but not thyroid cancer. Mendelian randomization did not support a causal link for obesity with benign nodular thyroid disease or thyroid cancer, although it did provide some evidence that individuals in the highest quartile for genetic liability of type 2 diabetes had higher odds of thyroid cancer than those in the lowest quartile (OR, 1.45; CI, 1.11-1.90).
Conclusions: Contrary to the findings of observational studies, our results do not confirm a causal role for obesity in benign nodular thyroid disease or thyroid cancer. They do, however, suggest a link between type 2 diabetes and thyroid cancer.This article is freely available via Open Access. Click on the Publisher URL to access it via the publisher's site.WT_/Wellcome Trust/United Kingdompublished version, accepted version (12 month embargo), submitted versio
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