474 research outputs found
Development of a bedrest muscle stress apparatus
In attempting further to define the deleterious effects of spaceflight on the human body, measurement systems and techniques were devised to determine the loss of skeletal muscle strength and tone as a result of spaceflight exposure. In order to determine how the muscle degradation process progresses with time during nonuse, a system for measuring muscle stress during bedrest was developed. The Bedrest Muscle Stress Apparatus is configured to slip snugly over the foot board of a standard hospital bed. Data collected with this device correlated well with pre- and post-bedrest data collected with the original skeletal muscle stress apparatus
Looking to the Future of Wildlife Conservation: Durable Wildlife Policy for the 21st Century
Wildlife conservation in the United States was built by the dollars of consumptive users. Monies from the sale of hunting licenses, as well as excise taxes on firearms, ammunition, and archery tackle through the Pittman-Robertson Federal Aid in Wildlife Restoration Act (PR), currently fuel a complex system of wildlife conservation via multiple levels of government. However, the number of hunters in this country is rapidly declining, the sale of firearms and ammunition is increasingly unrelated to hunting, and contemporary consumers tend to express different values than traditional hunters. These changes pose significant challenges of relevancy and funding to state and federal fish and wildlife agencies charged with wildlife management and conservation. This thesis seeks to contribute to three topics that are relevant to the future of the field of wildlife conservation by clarifying commonly used β but rarely defined β language, analyzing state-specific responses to declines in funding for conservation, and analyzing concerns regarding the North American Model of Wildlife Conservation.
The first chapter of this thesis aims to clarify terms commonly used in scholarship related to the take of wildlife to facilitate clear communication. When definitions vary among practitioners and academics, misunderstandings and breakdowns in communication arise. Reconciling distinctions between legal and social licensure facilitates more accurate depictions of take. The second chapter catalogues and analyzes dedicated revenue generated for state wildlife agencies via 25 distinct mechanisms and sought to identify factors which influence intrastate diversity in dedicated revenue. The third chapter examines a growing body of literature regarding the North American Model of Wildlife Conservation and finds significant variation in critiques of this concept. I address these concerns in the historical context of the model.
In short, this thesis addresses wildlife communication, the funding model of wildlife conservation, and a model which describes one interpretation of the laws and policies which differentiate wildlife conservation in the United States and Canada from the rest of the world. It is my hope that this work will be of some use to those who seek to conserve wildlife and wild places for future generations
Big five personality characteristics and commitment levels in romantic relationships
While numerous empirical studies have looked at commitment levels across various aspects of life, little research has attempted to integrate these disparate literatures. Accordingly, this study attempts to address this gap by adapting a taxonomy of commitment commonly used in the workplace to the analysis of commitment in romantic relationships. Additionally, the relationship between personality and levels of commitment in romantic relationships were investigated utilizing the Big Five personality factors. Results indicated that personality does relate to commitment and that the affective (emotional) and continuance (economic) facets of commitment have specific relevance to understanding commitment expressed in romantic relationships. Gender similarities and differences, as well as directions for future research, are discussed
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Electrokinetic removal of uranium from contaminated, unsaturated soils
Electrokinetic remediation of uranium-contaminated soil was studied in a series of laboratory-scale experiments in test cells with identical geometry using quartz sand at approximately 10 percent moisture content. Uranium, when present in the soil system as an anionic complex, could be migrated through unsaturated soil using electrokinetics. The distance that the uranium migrated in the test cell was dependent upon the initial molar ratio of citrate to uranium used. Over 50 percent of the uranium was recovered from the test cells using the citrate and carbonate complexing agents over of period of 15 days. Soil analyses showed that the uranium remaining in the test cells had been mobilized and ultimately would have been extracted. Uranium extraction exceeded 90 percent in an experiment that was operated for 37 days. Over 70 percent of the uranium was removed from a Hanford waste sample over a 55 day operating period. Citrate and carbonate ligand utilization ratios required for removing 50 percent of the uranium from the uranium-contaminated sand systems were approximately 230 moles ligand per mole uranium and 1320 moles ligand per mole uranium for the waste. Modifying the operating conditions to increasing the residence time of the complexants is expected to improved the utilization efficiency of the complexing agent
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Issues in RF propagation modeling in an urban environment using the Extended Air Defense Simulation (EADSIM) mission level model.
As military operations in urban environments become more numerous, the ability of combat units to communicate, jam enemy communications, or employ RF weapons within this environment must be evaluated. To perform this evaluation in a mission level model requires a capability to evaluate the contributions of both terrain and man-made structures (interior and exterior) to RF propagation. The present study is an analysis of the adequacy of a mission level model (EADSIM) to perform these RF propagation calculations in an urban environment. Three basic environments must be assessed. The first environment consists entirely of terrain, with no man-made features impacting propagation values. The second environment includes terrain, but also includes the contribution of solid structures with abrupt edges, which may obstruct/influence LOS paths. The third environment includes not only terrain and structures, but also contains structures with interior features which must be evaluated to determine the propagation levels within and around these structures. EADSIM was used as the model for evaluation in view of its suite of propagation tools which can be used for analysis of RF propagation between transmitters and receivers including terrain. To assess EADSIM's capability to perform in these environments, flat terrain maps with an obstruction were created to permit comparison of EADSIM's propagation models with analytical calculations and with measurements. Calculations from the Terrain Integrated Rough Earth Model (TIREM) and the Spherical Earth Knife Edge (SEKE) propagation models included within EADSIM showed that the ability of the models to calculate knife-edge diffraction agreed favorably with analytical values. The representation of multipath effects was less encouraging. SEKE only models multipath when Fresnel clearance exists. TIREM models multipath, but the cyclical characteristics of multipath are not represented, and only subtractive path loss is considered. Multipath is only evaluated along a 2-D path in the vertical orientation. This precludes modeling propagation in the urban canyons of metropolitan areas, where horizontal paths are dominant. It also precludes modeling exterior to interior propagation. In view of the apparent inadequacy of urban propagation within mission level models, as evidenced by EADSIM, the study also attempts to address possible solutions to the problem. Correction of the sparsing techniques in both TIREM and SEKE models is recommended. Both SEKE and TIREM are optimized for DTED level 1 data, sparsed at 3 arc seconds resolution. This led to significant errors when map data was sparsed at higher or lower resolution. TIREM's errors would be significantly reduced if the 999 point array limit was eliminated. This would permit using interval sizes equal to the map resolution for larger areas. This same problem could be fixed in SEKE by changing the interval spacing from a fixed 3 arc second resolution ({approx}93 meters) to an interval which is set at the map resolution. Additionally, the cell elevation interpolation method which TIREM uses is inappropriate for the man-made structures encountered in urban environments. Turning this method of determining height off, or providing a selectable switch is desired. In the near term, it appears that further research into ray-tracing models is appropriate. Codes such as RF-ProTEC, which can be dynamically linked to mission level models such as EADSIM, can provide the higher fidelity propagation calculations required, and still permit the dynamic interactions required of the mission level model. Additional research should also be conducted on the best methods of representing man-made structures to determine whether codes other than ray-trace can be used
Fission yeast 26S proteasome mutants are multi-drug resistant due to stabilization of the pap1 transcription factor
Here we report the result of a genetic screen for mutants resistant to the microtubule poison methyl benzimidazol-2-yl carbamate (MBC) that were also temperature sensitive for growth. In total the isolated mutants were distributed in ten complementation groups. Cloning experiments revealed that most of the mutants were in essential genes encoding various 26S proteasome subunits. We found that the proteasome mutants are multi-drug resistant due to stabilization of the stress-activated transcription factor Pap1. We show that the ubiquitylation and ultimately the degradation of Pap1 depend on the Rhp6/Ubc2 E2 ubiquitin conjugating enzyme and the Ubr1 E3 ubiquitin-protein ligase. Accordingly, mutants lacking Rhp6 or Ubr1 display drug-resistant phenotypes
From START to FINISH : the influence of osmotic stress on the cell cycle
Peer reviewedPublisher PD
How to design a complex behaviour change intervention: experiences from a nutrition-sensitive agriculture trial in rural India
Many public health interventions aim to promote healthful
behaviours, with varying degrees of success. With a lack
of existing empirical evidence on the optimal number or
combination of behaviours to promote to achieve a given
health outcome, a key challenge in intervention design
lies in deciding what behaviours to prioritise, and how
best to promote them. We describe how key behaviours
were selected and promoted within a multisectoral
nutrition-sensitive agriculture intervention that aimed to
address maternal and child undernutrition in rural India.
First, we formulated a Theory of Change, which outlined
our hypothesised impact pathways. To do this, we used
the following inputs: existing conceptual frameworks,
published empirical evidence, a feasibility study, formative
research and the intervention teamβs local knowledge.
Then, we selected specific behaviours to address within
each impact pathway, based on our formative research,
behaviour change models, local knowledge and community
feedback. As the intervention progressed, we mapped each
of the behaviours against our impact pathways and the
transtheoretical model of behaviour change, to monitor the
balance of behaviours across pathways and along stages
of behaviour change. By collectively agreeing on definitions
of complex concepts and hypothesised impact pathways,
implementing partners were able to communicate clearly
between each other and with intervention participants.
Our intervention was iteratively informed by continuous
review, by monitoring implementation against targets
and by integrating community feedback. Impact and
process evaluations will reveal whether these approaches
are effective for improving maternal and child nutrition,
and what the effects are on each hypothesised impact
pathway
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Contamination source review for Building E2370, Edgewood Area, Aberdeen Proving Ground, Maryland
The US Army Aberdeen Proving Ground (APG) commissioned Argonne National Laboratory (ANL) to conduct a contamination source review to identify and define areas of toxic or hazardous contaminants and to assess the physical condition and accessibility of APG buildings. The information obtained from this review may be used to assist the US Army in planning for the future use or disposition of the buildings. The contamination source review consisted of the following tasks: historical records search, physical inspection, photographic documentation, and geophysical investigation. This report provides the results of the contamination source review for Building E2370. Many of the APG facilities constructed between 1917 and the 1960s are no longer used because of obsolescence and their poor state of repair. Because many of these buildings were used for research, development, testing, and/or pilot-scale production of chemical warfare agents and other military substances, the potential exists for portions of the buildings to be contaminated with these substances, their degradation products, and other laboratory or industrial chemicals. These buildings and associated structures or appurtenances may contribute to environmental concerns at APG
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