5,924 research outputs found
Patch-Scale Movement Dynamics in the Iowa Grassland Butterflies \u3ci\u3eSpeyeria Cybele\u3c/i\u3e and \u3ci\u3eMegisto Cymela\u3c/i\u3e (Lepidoptera: Nymphalidae)
An understanding of the movement dynamics of invertebrates can be critical to their conservation, especially when managing relatively small, isolated habitats. Most studies of butterfly movement have focused on metapopulation dynamics at relatively large spatial scales, and the results from these studies may not translate well for patchy populations within a single nature preserve. In this work we use individual mark and recapture (IMR) methods to follow the movements of two species of butterfly, Megisto cymela (Cramer) and Speyeria cybele F. (Lepidoptera: Nymphalidae) within a 240 hectare forest and grassland preserve in central Iowa, USA. Significant redistribution was seen in both species, with 55.7% of S. cybele and 31.1% of M. cymela undergoing interpatch movement. Median movement rates during the study were 105 m/day for S. cybele and 38 m/day for M. cymela, with the top decile moving at a rate of over five times these values. This movement did not appear to be random. S. cybele exhibited directed movement towards patches with high nectaring potential, although not all such patches were selected. M. cymela aggregated in particular prairie patches, especially those with high edge to area ratios, although the reason for aggregation is not clear
Recommended from our members
Aligning Community-Engaged Research to Context.
Community-engaged research is understood as existing on a continuum from less to more community engagement, defined by participation and decision-making authority. It has been widely assumed that more is better than less engagement. However, we argue that what makes for good community engagement is not simply the extent but the fit or alignment between the intended approach and the various contexts shaping the research projects. This article draws on case studies from three Community Engagement Cores (CECs) of NIEHS-funded Environmental Health Science Core Centers (Harvard University, UC Davis and University of Arizona,) to illustrate the ways in which community engagement approaches have been fit to different contexts and the successes and challenges experienced in each case. We analyze the processes through which the CECs work with researchers and community leaders to develop place-based community engagement approaches and find that different strategies are called for to fit distinct contexts. We find that alignment of the scale and scope of the environmental health issue and related research project, the capacities and resources of the researchers and community leaders, and the influences of the sociopolitical environment are critical for understanding and designing effective and equitable engagement approaches. These cases demonstrate that the types and degrees of alignment in community-engaged research projects are dynamic and evolve over time. Based on this analysis, we recommend that CBPR scholars and practitioners select a range of project planning and management techniques for designing and implementing their collaborative research approaches and both expect and allow for the dynamic and changing nature of alignment
Evaluation of Risk Management Methods for Satsuma Mandarin
Simulation of production budgets were used to compare net discounted returns and the distribution of returns under alternative risk-mitigation scenarios. Results indicate that the combination of freeze protection and crop insurance increases expected net discounted 20-year returns while decreasing the downside risk. Break-even prices ranged from .289 per pound. Crop insurance returns were constant across price.Satsuma oranges, freeze protection, crop insurance, production budget, simulation, Crop Production/Industries, Farm Management, Risk and Uncertainty, C63, D81, Q12,
A Reactive Molecular Dynamics Model for Uranium/Hydrogen Containing Systems
Uranium-based materials are valuable assets in the energy, medical, and
military industries. However, understanding their sensitivity to hydrogen
embrittlement is particularly challenging due to the toxicity of uranium and
computationally expensive nature of the quantum-based methods generally
required to study such processes. In this regard, we have developed a Chebyshev
Interaction Model for Efficient Simulation (ChIMES) model that can be employed
to compute energies and forces of U and UH3 bulk structures with vacancies and
hydrogen interstitials with similar accuracy to Density Functional Theory (DFT)
while yielding linear scaling and orders of magnitude improvement in
computational efficiency. We show that that the bulk structural parameters,
uranium and hydrogen vacancy formation energies, and diffusion barriers
predicted by the ChIMES potential are in strong agreement with the reference
DFT data. We then use ChIMES to conduct molecular dynamics simulations of the
temperature-dependent diffusion of a hydrogen interstitial and determine the
corresponding diffusion activation energy. Our model has particular
significance in studies of actinides and other high-Z materials, where there is
a strong need for computationally efficient methods to bridge length and time
scales between experiments and quantum theory.Comment: Reactive molecular dynamics model for U/H systems based on the ChIMES
reactive force fiel
Theoretical modeling of propagation of magneto-acoustic waves in magnetic regions below sunspots
We use 2D numerical simulations and eikonal approximation, to study
properties of MHD waves traveling below the solar surface through the magnetic
structure of sunspots. We consider a series of magnetostatic models of sunspots
of different magnetic field strengths, from 10 Mm below the photosphere to the
low chromosphere. The purpose of these studies is to quantify the effect of the
magnetic field on local helioseismology measurements by modeling waves excited
by sub-photospheric sources. Time-distance propagation diagrams and wave travel
times are calculated for models of various field strength and compared to the
non-magnetic case. The results clearly indicate that the observed time-distance
helioseismology signals in sunspot regions correspond to fast MHD waves. The
slow MHD waves form a distinctly different pattern in the time-distance
diagram, which has not been detected in observations. The numerical results are
in good agreement with the solution in the short-wavelength (eikonal)
approximation, providing its validation. The frequency dependence of the travel
times is in a good qualitative agreement with observations.Comment: accepted by Ap
Athletic Training Student and Student Aide Clinical Task Allowance in the Secondary School Setting
Purpose: Athletic training student aides (SA) are minors in high school that participate in an athletic training experience under the supervision of secondary school athletic trainers (SSAT). The NATA published an official statement on the proper supervision of SAs related to task allowance. As SSATs may also supervise athletic training students (ATSs), it is important to understand the differences in both. Therefore, the objective was to explore the training, task allowance, and perspectives of SAs and ATSs by SSATs during clinical experiences. Methods: We used a cross-sectional, web-based survey for this study. SSATs (n=3,567) from the ATLAS database were recruited and 614 participants (age=39±11years, years credentialed=12±9years) completed the study. An online survey was developed to reflect the NATA official statement for task allowance and supervision of SAs and ATSs. Dependent variables included requirements and task allowance of the SA and ATS based on supervision (direct, autonomous, and restricted), and the personal perceptions from SSATs. Results: 76.5% of SSATs reported having SAs involved in their clinical practice. Less than 50% of SSATs implemented recommended trainings related to emergency preparedness, first aid, and patient privacy. When exploring task allowance, most SSATs were following best practice guidelines for job-related tasks. Additionally, SSATs were allowing ATSs to perform more tasks autonomously as compared to SAs. Conclusions: SSATs are mostly following best practice recommendations for task allowance, whereby they are providing supervision to SAs in the appropriate areas and not allowing certain duties. However, 100% compliance was not met, thus increasing risks to patients and the profession. SSATs should improve training and preparedness for the SAs involved in their clinical practice Additionally, SSATs are allowing ATSs to perform job-related tasks autonomously or with directed supervision during clinical experiences with the exception to administrative tasks and autonomous clinical-decision making
Letter from the Nuclear Security Women Editors
Letter from the Nuclear Security Women Editors for the IJNS and NSW Special Issue: Women in Nuclear Securit
Simulation to Support Local Search in Trajectory Optimization Planning
NASA and the international community are investing in the development of a commercial transportation infrastructure that includes the increased use of rotorcraft, specifically helicopters and civil tilt rotors. However, there is significant concern over the impact of noise on the communities surrounding the transportation facilities. One way to address the rotorcraft noise problem is by exploiting powerful search techniques coming from artificial intelligence coupled with simulation and field tests to design low-noise flight profiles which can be tested in simulation or through field tests. This paper investigates the use of simulation based on predictive physical models to facilitate the search for low-noise trajectories using a class of automated search algorithms called local search. A novel feature of this approach is the ability to incorporate constraints directly into the problem formulation that addresses passenger safety and comfort
Lessons Learned: Facilitating a Health and Wellness Intervention for Frontline Child Welfare Workers during COVID-19
Child maltreatment is one of the nation’s most significant public health concerns. The estimated annual economic burden of child maltreatment in the United States is more than 292 billion (Peterson et al., 2018). In 2021, approximately four million referrals were made to child protective service agencies alleging the maltreatment of more than seven million children (U.S. Department of Health and Human Services [HHS], 2023). The primary mechanism for evaluating these referrals is the frontline child welfare workforce. Frontline child welfare workers (FCWWs) engage families and make decisions about the
safety of children that directly impact children’s futures (Edwards & Wildeman, 2018). High levels of worker turnover, agency understaffing, and an inexperienced workforce constitute a national problem with concerning implications. FCWWs often prematurely leave their positions, with the average tenure being less than two years (Edwards & Wildeman, 2018). Turnover among practitioners is expensive. The estimated fiscal cost to agencies for each practitioner leaving their position
is 54,000 (National Child Welfare Workforce Institute, 2016). Further, service delivery, continuity of care, and performance standards are negatively impacted when workers leave their positions (Scannapieco & Connell-Carrick, 2007)
State transition of a non-Ohmic damping system in a corrugated plane
Anomalous transport of a particle subjected to non-Ohmic damping of the power
in a tilted periodic potential is investigated via Monte Carlo
simulation of generalized Langevin equation. It is found that the system
exhibits two relative motion modes: the locking state and the running state.
Under the surrounding of sub-Ohmic damping (), the particle should
transfer into a running state from a locking state only when local minima of
the potential vanish; hence the particle occurs a synchronization oscillation
in its mean displacement and mean square displacement (MSD). In particular, the
two motion modes are allowed to coexist in the case of super-Ohmic damping
() for moderate driving forces, namely, where exists double centers
in the velocity distribution. This induces the particle having faster
diffusion, i.e., its MSD reads . Our result shows that the effective power index
can be enhanced and is a nonmonotonic function of the
temperature and the driving force. The mixture effect of the two motion modes
also leads to a breakdown of hysteresis loop of the mobility.Comment: 7 pages,7 figure
- …