1,079 research outputs found
Modeling Summer Habitat Selection of Sympatric Bighorn Sheep and Mountain Goats in the Greater Yellowstone Area
With introduced mountain goat (Oreamnos americanus) populations continuing to expand throughout the mountainous regions of the greater Yellowstone area (GYA), wildlife managers have expressed a need for reliable information to understand mountain goat ecology specific to this region as well as any potential impacts to native species and communities, especially to native and restored bighorn sheep populations. In response to this need for ecological knowledge, we developed and implemented rigorous occupancy survey methodologies in two study areas for three field seasons (2011-2013). A total of 611 surveys were performed over 550 observer-days, capturing spatially-precise locations of 128 bighorn sheep groups and 286 mountain goat groups. These data are being used to develop fine-scale summer habitat-selection models for both mountain goats and bighorn sheep that account for imperfect detection. This presentation reports on the accomplishments from the three field seasons, including what we have learned from preliminary analyses and the next steps to completing a full analysis of the data. Products from this research will provide insight into the potential for resource competition between bighorn sheep and mountain goats. Development of a mountain goat habitat-selection model will also allow prediction of range expansion of mountain goats into the extensive ranges of bighorn sheep in the eastern mountains of the GYA where small numbers of colonizing mountain goats have recently been observed
Preliminary Results of Occupancy Surveys for Modeling Habitat Selection of Sympatric Bighorn Sheep and Mountain Goats in the Greater Yellowstone Area
Introduced and expanding mountain goat (Oreamnos americanus) populations in the greater Yellowstone area (GYA) have generated significant concern regarding impacts to natural communities, and especially to native and restored bighorn sheep (Ovis Canadensis) populations. To provide natural resource managers with useful and applicable information for managing and conserving these species, occupancy surveys based on rigorous field studies were implemented in 2011 and 2012 to develop summer habitat models for bighorn sheep and mountain goats in the GYA. To enhance the applicability and accuracy of these models, occupancy probabilities obtained from presence and absence observations are integrated with detection probabilities gained from double independent-observer sampling. Between the two field seasons, a total of 361 surveys were performed over 350 observer- days, capturing spatially-precise locations of 80 bighorn sheep groups and 138 mountain goat groups. Preliminary analyses of the data obtained to date were performed for each species to gauge the utility of the field studies and to provide insights for improved study design and implementation of future field work. This presentation reports on the accomplishments from the first two field seasons, including what we have learned from preliminary analyses and the plans for an additional field season for summer 2013
Learning about compact binary merger: the interplay between numerical relativity and gravitational-wave astronomy
Activities in data analysis and numerical simulation of gravitational waves
have to date largely proceeded independently. In this work we study how
waveforms obtained from numerical simulations could be effectively used within
the data analysis effort to search for gravitational waves from black hole
binaries. We propose measures to quantify the accuracy of numerical waveforms
for the purpose of data analysis and study how sensitive the analysis is to
errors in the waveforms. We estimate that ~100 templates (and ~10 simulations
with different mass ratios) are needed to detect waves from non-spinning binary
black holes with total masses in the range 100 Msun < M < 400 Msun using
initial LIGO. Of course, many more simulation runs will be needed to confirm
that the correct physics is captured in the numerical evolutions. From this
perspective, we also discuss sources of systematic errors in numerical waveform
extraction and provide order of magnitude estimates for the computational cost
of simulations that could be used to estimate the cost of parameter space
surveys. Finally, we discuss what information from near-future numerical
simulations of compact binary systems would be most useful for enhancing the
detectability of such events with contemporary gravitational wave detectors and
emphasize the role of numerical simulations for the interpretation of eventual
gravitational-wave observations.Comment: 19 pages, 12 figure
When daily planning improves employee performance: the importance of planning type, engagement, and interruptions
Does planning for a particular workday help employees perform better than on other days they fail to plan? We investigate this question by identifying two distinct types of daily work planning to explain why and when planning improves employees’ daily performance.
The first type is time management planning (TMP)—creating task lists, prioritizing tasks, and determining how and when to perform them. We propose that TMP enhances employees’ performance by increasing their work engagement, but that these positive effects are weakened when employees face many interruptions in their day.
The second type is contingent planning (CP) in which employees anticipate possible interruptions in their work and plan for them. We propose that CP helps employees stay engaged and perform well despite frequent interruptions. We investigate these hypotheses using a two-week experience-sampling study. Our findings indicate that TMP’s positive effects are conditioned upon the amount of interruptions, but CP has positive effects that are not influenced by the level of interruptions.
Through this study, we help inform workers of the different planning methods they can use to increase their daily motivation and performance in dynamic work environments
Citizenship Documentation Requirement for Medical Eligibility: Effects on Oregon Children
BACKGROUND AND OBJECTIVES: The Deficit Reduction Act (DRA) of 2005 mandated Medicaid beneficiaries to document citizenship. Using a prospective cohort (n=104,375), we aimed to (1) determine characteristics of affected children, (2) describe effects on health insurance coverage and access to needed health care, and (3) model the causal relationship between this new policy, known determinants of health care access, and receipt of needed health care. METHODS: We identified a stratified random sample of children shortly after the DRA was implemented and used state records and surveys to compare three groups: children denied Medicaid for inability to document citizenship, children denied for other reasons, and children accepted for coverage. To combat survey nonresponse, we used Medicaid records to identify differences between responders and nonrespondents and created survey weights to account for these differences. Weighted simple and multivariable logistic regression described the complete, originally identified population. RESULTS: Children denied Medicaid for inability to document citizenship were likely to be US citizens, were medically and socially more vulnerable than their peers, and went on to have gaps in health insurance coverage and unmet health care needs. The DRA led to persistent loss of insurance coverage, which decreased access to needed health care. Having a usual source of care was an effect modifier in this relationship. CONCLUSIONS: Our findings demonstrate the negative consequences of the DRA and support the use of automated methods of citizenship verification allowed under the Patient Protection and Affordable Care Act
Pretreatment nutritional status and response to checkpoint inhibitors in lung cancer.
Background:Checkpoint inhibitors are integral to non-small-cell lung cancer treatment. Existing data suggests that nutritional status may play a role in antitumor immunity. Materials & methods:This retrospective study of 106 non-small-cell lung cancer patients who started checkpoint inhibitors between 2014 and 2017 at our institution assessed relationship of nutritional parameters to overall survival (OS) and progression-free survival. Results:Mean age was 68.7 ± 9.2 years and 59.4% patients were male. On multivariate analysis for OS, hypoalbuminemia and significant weight loss were prognostic at p-values of 0.0005 and 0.0052, respectively. We noted a parabolic association between age and OS (p = 0.026, 0.0025). Conclusion:In our study, some malnutrition parameters were associated with decreased OS. U-shape relationship between age and OS noted here warrants further evaluation
- …