526 research outputs found
The Effects of Red Imported Fire Ants on Northern Bobwhite and Eastern Cottontail in the Gulf Prairies and Marshes of Texas
Northern bobwhites (Colinus virginianus) have been declining throughout their range since the 1960s. The decline in the Gulf Prairies and Marshes Ecoregion (GPM) has primarily been the result of habitat loss and fragmentation. With the population already reduced, additional causes of quail decline become important issues. In 1957, red imported fire ants (RIFA, Solenopsis invicta) began to invade the GPM. RIFA can potentially affect bobwhites by direct predation of pipping chicks, reduced survival of young chicks, and competition for food. Eastern cottontails are another important species that could be impacted by RIFA. Previous work has documented RIFA predation of altricial young born in pen-raised cottontail nests.
The Attwater Prairie Chicken National Wildlife Refuge in Colorado County, Texas received large-scale aerial treatment of RIFA with Extinguish Plus™ insecticide as a management action for the endangered Attwater’s prairie-chicken (Tympanuchus cupido attwateri). This presented me with an opportunity to evaluate the effects of RIFA treatment on: (1) bobwhite nest success and brood survival, (2) bobwhite abundance and density, (3) bobwhite movements and ranges, and (4) cottontail numbers. An additional objective was to (5) contribute reference data for bobwhite in the GPM to address this region’s lack of data. To investigate these objectives bobwhites were radio-collared and tracked, RIFA were sampled, and cottontails were surveyed in both the treated and non-treated areas.
Treatment with Extinguish Plus™ successfully reduced the abundance of RIFA in iii the treated area from 2014–2017. However, I found that flooding can negate the effectiveness of the treatment when the treated area is surrounded by adjacent non-treated areas. Bobwhite densities were 76.6% higher (P = 0.042) in the treated area compared to the non-treated area. There was no difference between bobwhite consecutive movements (P = 0.275) or seasonal ranges (P = 0.783) in the treated and non-treated area. However, there was a difference (P = <0.001) by category. Nesting season females without a brood had larger movements (P = <0.001) than nesting season females with a brood and larger movements (P = 0.002) than pre-nesting females. Cottontail numbers were higher (P = 0.003) in the non-treated than the treated area
An Inquiry Into the Moral Significance of Doxastic and Epistemic States: Examining the Circumstantial Element of Moral Obligation
This thesis explores the moral significance of agent beliefs and epistemic states. In particular it will explore the following question: is an agent\u27s moral obligation a function of her actual circumstances, what she believes those circumstances to be, or what her evidence indicates those circumstances are? Three corresponding views are explored and it is argued that each of these views is subject to one of two substantial worries, which are developed in this thesis (i.e. the manipulation worry and the unreasonableness worry)
Tuning the plasmonic properties of silver nanopatterns fabricated by shadow nanosphere lithography
Regular silver (Ag) nanopatterns, from disconnected nanotriangles to well coupled triangular clusters of nanoparticles, were prepared by shadow nanosphere lithography at different incident angles θ from 0 degrees to 20 degrees with continuous azimuthal rotation. The resulting nanopatterns were consistent with predictions by numerical calculations and Monte Carlo simulations of adatoms with high diffusivity. The visible localized surface plasmon resonance of these nanopatterns was tuned by θ systematically due to the change in size, shape, and arrangement of Ag nanopatterns. These resonances were consistent with finite-difference time-domain simulations using realistic nanopatterns based upon scanning electron micrographs. Such a simple fabrication strategy can be used to optimize surface enhanced Raman scattering substrate fabrication, as well as other plasmonics based applications
Impact of First Occupation on Health at Older Ages
Occupation is discussed as a social determinant of health. Occupation has received little attention in this light in the economics literature. We examine occupation in a life-course framework and use measures of first-occupation, initial health, and mother’s education. We contend that first occupation is a choice made relatively early in life that affects health outcomes at later ages. We examine first-occupation for two reasons: 1) there is growing evidence that early determinants affect later health and occupation has received little attention in this regard and 2) first occupation is predetermined in analysis of later health, which helps to address the issue of potential simultaneity. Using data from the Panel Study of Income Dynamics (PSID) we estimate the impact of initial occupation on two measures of health later in life: respondent-reported fair/poor health and ever suffering a heart attack. The PSID offers the opportunity to examine a lifecycle perspective as we can examine the impact of early occupation on later health while controlling for several predetermined conditions such as mother’s education and health in youth. Estimates suggest that first-occupation has a durable impact on later health, ceteris paribus, but that the impact varies by health measure and the set of control variables in regression specifications. Early choice of occupation could be a critical factor in successful aging and this information may pave the way to developing more effective workplace and public policies to improve health in older ages.
Design of Force Indicator for Ballistic Armor Trauma Pad
The purpose of the Force Indicator for Ballistic Armor Vests is to obtain an approximate value for the impact a bullet delivers through a trauma pad after the Kevlar layer stops the initial bullet. This approximation will be applied in the field to assist in medical treatment of gunshot wounds. The indicator is made from a pressure-sensitive film located behind the Kevlar layer and trauma pad, and it can be easily removed in the field for examination. The impact vest and force indicator are self-contained for ease of implementation. The device will be tested with 9mm, .22 Long Rifle, and .357 Magnum ammunition to visualize the differences in impact pressure between different bullet calibers. This result will be used to create a device by which injuries resulting from the impact of a bullet can be predicted, as well as to verify this device’s functionality in testing
Strategic Resource Allocation: Selecting Vessels to Support Maritime Irregular Warfare
The article of record as published may be found at http://dx.doi.org/10.5711/1082598318321The US Navy is at a critical juncture in
determining the types and numbers
of ships it will acquire, retire, and
sustain to support an evolving US military
strategy. In addition to determining how
many aircraft carriers, cruisers, amphibious
assault craft, fighters, and helicopters it will
need, the Navy must determine how it will
confront maritime irregular warfare. Assuming
an environment of resource scarcity,
where new vessel acquisition to support
maritime irregular warfare may be increasingly
difficult or unlikely, we introduce a
method for evaluating the capability and
costs of candidate vessels that are in the
current Department of Defense inventory, or
widely available from the commercial sector
to conduct such a mission. Our method
combines wargaming with cost analysis to
aid Navy leadership in developing maritime
irregular warfare concepts of operation as
well as resource allocation decisions.RAND CorporationAcquisition Research ProgramRAND CorporationAcquisition Research Progra
THE PHOTORECEPTORS AND NEUROTRANSMITTERS DRIVING SUBCONCOIUS RESPONSES TO LIGHT
Our sensory systems allow us to detect and successfully navigate the environment. The visual system translates environmental light into our conscious perception of sight, as well as subconscious physiological responses such as circadian photoentrainment, the pupillary light reflex, and mood modulation among others. The first step in these processes is photon detection by photoreceptors in the neural retina of the eye. In mammals, 3 general classes of photoreceptors exist: rods, cones, and intrinsically photosensitive retinal ganglion cells (ipRGCs). ipRGCs, in addition to being photoreceptors, are the critical relay for light information from rods and cones to brain areas responsible for the subconscious responses to light. In order for this light information to get to the brain, ipRGCs are known to employ 2 distinct neurotransmitters: glutamate and PACAP. However, the contribution of each photoreceptor and neurotransmitter to subconscious behaviors remains unclear. In this thesis, I demonstrate the role each photoreceptor plays in responding to the multitude of potential environmental light conditions. I show, similar to the photoreceptors, the neurotransmitters relay distinct and necessary aspects of the information detected by the photoreceptors. In addition, I identify novel neurotransmitters within subsets of ipRGCs which may be responsible for relaying their own unique aspect of the light environment to the brain
Relevant Restaurant Interests to Partnering with Non-Profit Organizations
Mealshare is a newly formed non-profit organization that partners with restaurants to feed persons in need. We conducted exploratory and quantitative research on Edmonton and area restaurants to identify those restaurant interests leading to partnerships with non-profit organizations. By performing in-depth interviews with restaurant owners and managers within Edmonton, we discovered main themes such as marketing benefits of social responsibility, preferences for charities to donate to, concerns about charity work, and influences on choosing social responsibility efforts. A questionnaire was developed and distributed to restaurant owners and managers, from which we derived tentative conclusions and recommendations to enhance the Mealshare brand and identify future opportunities. Based on the findings, we find that Mealshare should focus on configuring their marketing activities to emphasize community involvement, time constraint management, and marketing benefits, as well as tailor themselves for independently owned restaurants
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