2,962 research outputs found

    A Visual Impact Assessment Methodology for the National Park Service

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    As the National Park Service (NPS) set out to create a visual resource management program, the first major component was the development of a robust visual resource inventory (VRI) process to identify, locate, and assess high value views, both within and near NPS units, based on both scenic quality and the importance of the view to the visitor experience. The next component in the program has been the development of a visual impact assessment (VIA) process to understand how changes in the landscape— whether inside the park or beyond its boundaries—could impact the scenic quality of valued views and visitor experience of those views. This presentation will discuss the NPS VIA process and highlight results of field-testing. Units of the National Park System encompass a wide variety of landscape types and visual settings. Particular views are enjoyed not only for scenic qualities but also appreciated for their historic and cultural values. NPS incorporates visible elements of views into their interpretive and educational activities. As a result, the NPS VRI was designed to identify not only the visual qualities of views but also the other values that make views important to NPS and park visitors. The NPS VRI was also built to support VIAs, both for NPS projects and actions within NPS unit boundaries, and projects and activities beyond NPS unit boundaries, where NPS is a stakeholder rather than a permitting agency. The detailed information from the VRI provides a sound basis for articulating the full effects of a proposed project or activity, which may go far beyond measuring visual contrast and other more purely scenic aspects of visual impact. Building on the inventory process the NPS visual impact assessment (VIA) methodology identifies the expected level of visual change from a proposed project or activity, and assesses the likely effects of the change on scenic quality as determined in the VRI. The NPS VIA approach provides parks with information to pursue better planning and design for park projects and credible support for understanding and communicating the potential impacts of changes beyond park boundaries

    Impacts of Red Imported Fire Ants on Northern Bobwhite Nest Survival

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    Invasive species are a large management issue because of extensive environmental and economic damage. The red imported fire ant (RIFA, Solenopsis invicta) is an invasive species of growing concern in wildlife management in the United States because of its increasing distribution, difficulty to suppress, and aggressive predation on native invertebrates, herpetofauna, birds, and small mammals. Managers of the northern bobwhite (Colinus virginianus) have questioned the direct impact of RIFA on bobwhite nest success, particularly the factors that might influence the level of nest predation. We hypothesized that RIFA predation on northern bobwhite would vary by location and correlate with drier weather conditions. To test our hypothesis we analyzed bobwhite nest data gathered from 3 properties in the southeastern United States. The nest data are part of a larger research effort on bobwhites, collected by Tall Timbers Research Station and the Albany Quail Project using radiotelemetry from 1992 to 2015. Over these 23 years we tracked bobwhites and located nests (n = 3,207) daily to determine nest fate (success or failure) based on field sign and evidence attributed to specific causes of mortality. We used the nest-survival model in Program MARK to estimate nest survival. Average nest survival varied annually for the Albany and Tall Timbers study areas, respectively. The overall effect of RIFAs on nest survival was generally small, with an average annual loss in Albany of 5.13% (range = 0–15.59%) and 2.17% in Tall Timbers (range = 0–5.83%), but in some years was as high as 15.6%. Greater losses occurred late in the breeding season when it was typically drier and the loss rate in general was higher on the drier of the 2 study sites. Despite the relatively small direct impact on nesting success demonstrated, indirect effects of RIFAs on bobwhite populations are poorly understood at present. Quantifying the influence of indirect factors, such as soil type and habitat disturbance, on RIFA abundance and the subsequent impact on bobwhites, will provide additional insight to the ecological interaction with a highly pervasive and expanding invasive species and help inform management options

    Genetic Resources for the Improvement of Switchgrass (\u3cem\u3ePanicum virgatum\u3c/em\u3e L.) for Biomass and Forage

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    Switchgrass (Panicum virgatum L.) is an important forage and biomass species for many parts of the USA. Switchgrass can be of several ploidies. Octoploid cultivars are most often used in forage and conservation settings, while the tetraploid cultivars are mostly targeted for bioenergy end-uses, due to their higher biomass yields. Switchgrass populations also occur as upland and lowland ecotypes, and constitute different heterotic groups. Switchgrass is mostly an obligate outcrosser resulting in substantial genotypic and phenotypic variation within populations. In the last ~15 years, significant resources have been dedicated to both breeding and understanding the genomic makeup of this plant, with a focus on bioenergy. This investment has resulted in the development of elite lines as well as a considerable increase in available genetic, physiological, and biomass-related information. The United States Department of Agriculture-Agricultural Research Service has been a major player in these developments (Mitchell and Schmer, 2012; Vogel et al., 2011). With significant improvements in DNA-sequencing technologies (High Throughput Sequencing, HTS), it has become possible to undertake large-scale analysis of both the genomic and functional genomic components of switchgrass. One such undertaking by the United States Department of Energy-Joint Genomics Institute has provided a draft assembly and annotation of the switchgrass genome (www.phytozome.org). This remarkable resource has permitted a complete utilization of HTS to analyze gene expression using RNA-Seq and related bioinformatic pipelines. Large-scale studies that are performed using field-grown plants and populations with well-characterized phenotypic traits, it increases the likelihood of discovering molecular events that underpin phenomena of interest. Even though lowland tetraploid cultivars have higher biomass yields than upland tetraploid cultivars, they can suffer significant winter-kill in more northern locations (Central Great Plains of the USA). Winter-kill is associated with the loss of rhizomes and other perenniating structures resulting in a complete or partial loss of tillering ability in the following seasons. Partial attrition of tiller production serves to limit new rhizome growth in successive years. One or more cycles of winter kill will ultimately kill the plant. We are trying to understand the cellular metabolism associated with the onset of rhizome dormancy and to connect the links between tiller/leaf senescence and rhizome metabolism using field grown plants from diverse populations, HTS and RNA-Seq

    Measurements of Airborne Influenza Virus in Aerosol Particles from Human Coughs

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    Influenza is thought to be communicated from person to person by multiple pathways. However, the relative importance of different routes of influenza transmission is unclear. To better understand the potential for the airborne spread of influenza, we measured the amount and size of aerosol particles containing influenza virus that were produced by coughing. Subjects were recruited from patients presenting at a student health clinic with influenza-like symptoms. Nasopharyngeal swabs were collected from the volunteers and they were asked to cough three times into a spirometer. After each cough, the cough-generated aerosol was collected using a NIOSH two-stage bioaerosol cyclone sampler or an SKC BioSampler. The amount of influenza viral RNA contained in the samplers was analyzed using quantitative real-time reverse-transcription PCR (qPCR) targeting the matrix gene M1. For half of the subjects, viral plaque assays were performed on the nasopharyngeal swabs and cough aerosol samples to determine if viable virus was present. Fifty-eight subjects were tested, of whom 47 were positive for influenza virus by qPCR. Influenza viral RNA was detected in coughs from 38 of these subjects (81%). Thirty-five percent of the influenza RNA was contained in particles \u3e4 ”m in aerodynamic diameter, while 23% was in particles 1 to 4 ”m and 42% in particles \u3c1 ”m. Viable influenza virus was detected in the cough aerosols from 2 of 21 subjects with influenza. These results show that coughing by influenza patients emits aerosol particles containing influenza virus and that much of the viral RNA is contained within particles in the respirable size range. The results support the idea that the airborne route may be a pathway for influenza transmission, especially in the immediate vicinity of an influenza patient. Further research is needed on the viability of airborne influenza viruses and the risk of transmission

    Secondary Sex Ratio among Women Exposed to Diethylstilbestrol in Utero

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    BACKGROUND. Diethylstilbestrol (DES), a synthetic estrogen widely prescribed to pregnant women during the mid-1900s, is a potent endocrine disruptor. Previous studies have suggested an association between endocrine-disrupting compounds and secondary sex ratio. METHODS. Data were provided by women participating in the National Cancer Institute (NCI) DES Combined Cohort Study. We used generalized estimating equations to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the relation of in utero DES exposure to sex ratio (proportion of male births). Models were adjusted for maternal age, child's birth year, parity, and cohort, and accounted for clustering among women with multiple pregnancies. RESULTS. The OR for having a male birth comparing DES-exposed to unexposed women was 1.05 (95% CI, 0.95-1.17). For exposed women with complete data on cumulative DES dose and timing (33%), those first exposed to DES earlier in gestation and to higher doses had the highest odds of having a male birth. The ORs were 0.91 (95% C, 0.65-1.27) for first exposure at ≄ 13 weeks gestation to < 5 g DES; 0.95 (95% CI, 0.71-1.27) for first exposure at ≄ 13 weeks to ≄ 5 g; 1.16 (95% CI, 0.96-1.41) for first exposure at < 13 weeks to < 5 g; and 1.24 (95% CI, 1.04-1.48) for first exposure at < 13 weeks to ≄ 5 g compared with no exposure. Results did not vary appreciably by maternal age, parity, cohort, or infertility history. CONCLUSIONS. Overall, no association was observed between in utero DES exposure and secondary sex ratio, but a significant increase in the proportion of male births was found among women first exposed to DES earlier in gestation and to a higher cumulative dose.National Cancer Institute (N01-CP-21168, N01-CP-51017, N01-CP-01289

    Urogenital Abnormalities in Men Exposed to Diethylstilbestrol in Utero: A Cohort Study

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    Background: Diethylstilbestrol (DES), a synthetic estrogen widely prescribed to pregnant women during the 1940s70s, has been shown to cause reproductive problems in the daughters. Studies of prenatally-exposed males have yielded conflicting results. Methods: In data from a collaborative follow-up of three U.S. cohorts of DES-exposed sons, we examined the relation of prenatal DES exposure to occurrence of male urogenital abnormalities. Exposure status was determined through review of prenatal records. Mailed questionnaires (1994, 1997, 2001) asked about specified abnormalities of the urogenital tract. Risk ratios (RR) were estimated by Cox regression with constant time at risk and control for year of birth. Results: Prenatal DES exposure was not associated with varicocele, structural abnormalities of the penis, urethral stenosis, benign prostatic hypertrophy, or inflammation/infection of the prostate, urethra, or epididymus. However, RRs were 1.9 (95% confidence interval 1.13.4) for cryptorchidism, 2.5 (1.54.3) for epididymal cyst, and 2.4 (1.54.4) for testicular inflammation/ infection. Stronger associations were observed for DES exposure that began before the 11th week of pregnancy: RRs were 2.9 (1.65.2) for cryptorchidism, 3.5 (2.06.0) for epididymal cyst, and 3.0 (1.75.4) for inflammation/infection of testes. Conclusion: These results indicate that prenatal exposure to DES increases risk of male urogenital abnormalities and that the association is strongest for exposure that occurs early in gestation. The findings support the hypothesis that endocrine disrupting chemicals may be a cause of the increased prevalence of cryptorchidism that has been seen in recent years

    Status of Muon Collider Research and Development and Future Plans

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    The status of the research on muon colliders is discussed and plans are outlined for future theoretical and experimental studies. Besides continued work on the parameters of a 3-4 and 0.5 TeV center-of-mass (CoM) energy collider, many studies are now concentrating on a machine near 0.1 TeV (CoM) that could be a factory for the s-channel production of Higgs particles. We discuss the research on the various components in such muon colliders, starting from the proton accelerator needed to generate pions from a heavy-Z target and proceeding through the phase rotation and decay (π→ΌΜΌ\pi \to \mu \nu_{\mu}) channel, muon cooling, acceleration, storage in a collider ring and the collider detector. We also present theoretical and experimental R & D plans for the next several years that should lead to a better understanding of the design and feasibility issues for all of the components. This report is an update of the progress on the R & D since the Feasibility Study of Muon Colliders presented at the Snowmass'96 Workshop [R. B. Palmer, A. Sessler and A. Tollestrup, Proceedings of the 1996 DPF/DPB Summer Study on High-Energy Physics (Stanford Linear Accelerator Center, Menlo Park, CA, 1997)].Comment: 95 pages, 75 figures. Submitted to Physical Review Special Topics, Accelerators and Beam

    Randomized Trial of Letrozole Following Tamoxifen as Extended Adjuvant Therapy in Receptor-Positive Breast Cancer: Updated Findings from NCIC CTG MA.17

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    Background: Most recurrences in women with breast cancer receiving 5 years of adjuvant tamoxifen occur after 5 years. The MA.17 trial, which was designed to determine whether extended adjuvant therapy with the aromatase inhibitor letrozole after tamoxifen reduces the risk of such late recurrences, was stopped early after an interim analysis showed that letrozole improved disease-free survival. This report presents updated findings from the trial. Methods: Postmenopausal women completing 5 years of tamoxifen treatment were randomly assigned to a planned 5 years of letrozole (n = 2593) or placebo (n = 2594). The primary endpoint was disease-free survival (DFS); secondary endpoints included distant disease-free survival, overall survival, incidence of contralateral tumors, and toxic effects. Survival was examined using Kaplan-Meier analysis and log-rank tests. Planned subgroup analyses included those by axillary lymph node status. All statistical tests were two-sided. Results: After a median follow-up of 30 months (range = 1.5-61.4 months), women in the letrozole arm had statistically significantly better DFS and distant DFS than women in the placebo arm (DFS: hazard ratio [HR] for recurrence or contralateral breast cancer = 0.58, 95% confidence interval [CI] = 0.45 to 0.76; P<.001; distant DFS: HR = 0.60, 95% CI = 0.43 to 0.84; P = .002). Overall survival was the same in both arms (HR for death from any cause = 0.82, 95% CI = 0.57 to 1.19; P = .3). However, among lymph node-positive patients, overall survival was statistically significantly improved with letrozole (HR = 0.61, 95% CI = 0.38 to 0.98; P = .04). The incidence of contralateral breast cancer was lower in women receiving letrozole, but the difference was not statistically significant. Women receiving letrozole experienced more hormonally related side effects than those receiving placebo, but the incidences of bone fractures and cardiovascular events were the same. Conclusion: Letrozole after tamoxifen is well-tolerated and improves both disease-free and distant disease-free survival but not overall survival, except in node-positive patient

    Anticipated regret to increase uptake of colorectal cancer screening (ARTICS):a randomised controlled trial

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    Objective. Screening is key to early detection of colorectal cancer. Our aim was to determine whether a simple anticipated regret (AR) intervention could increase colorectal cancer screening uptake. Methods. We conducted a randomised controlled trial of a simple, questionnaire-based AR intervention, delivered alongside existing pre-notification letters. 60,000 adults aged 50-74 from the Scottish National Screening programme were randomised to: 1) no questionnaire (control), 2) Health Locus of Control questionnaire (HLOC) or 3) HLOC plus anticipated regret questionnaire (AR). Primary outcome was guaiac Faecal Occult Blood Test (FOBT) return. Secondary outcomes included intention to return test kit and perceived disgust (ICK). Results. 59,366 people were analysed as allocated (Intentionto- treat (ITT)); there were no overall differences between treatment groups on FOBT uptake (control: 57.3%, HLOC: 56.9%, AR: 57.4%). 13,645 (34.2%) people returned questionnaires. Analysis of the secondary questionnaire measures showed that AR had an indirect effect on FOBT uptake via intention, whilst ICK had a direct effect on FOBT uptake over and above intention. The effect of AR on FOBT uptake was also moderated by intention strength: for less than strong intenders only, uptake was 4.2% higher in the AR (84.6%) versus the HLOC group (80.4%) (95% CI for difference (2.0, 6.5)). Conclusion. The findings show that psychological concepts including anticipated regret and perceived disgust (ICK) are important factors in determining FOBT uptake. However, there was no simple effect of the AR intervention in the ITT. We conclude that exposure to AR in those with low intentions may be required to increase FOBT uptake. Current controlled trials: www.controlledtrials. com number: ISRCTN74986452
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