710 research outputs found
Real-time engagement area dvelopment program (READ-Pro)
The Real-Time Engagement Area Development Program (READ-Pro) is a PC-based prototype system which provides company-level commanders with real-time operational analysis tools to develop engagement areas (EA) for direct fire (DF) systems. READ-Pro automates and streamlines the current manual system. READ-Pro significantly enhances the evaluation of a defense by presenting the commander with a visual display of the coverage and a quantitative measure of its fragility. READ-Pro also supports the rapid evolution to a better defense by providing visualization of the coverage and a quantitative evaluation at each step in the engagement area development process. READ-Pro creates a layered environment consisting of digital terrain elevation data (DTED), a standard military map, overlays, and imagery. A ModSAF line-of-sight (MLOS) algorithm, based on the ModSAF terrain model, calculates measures of effectiveness related to line-of-sight coverage. READ-Pro also includes a Monte-Carlo Simulation to quantify the fragility of a defense. READ-Pro incorporates the tactics, techniques and procedures used in today's Army, namely the troop-leading procedures and 7 steps of engagement area development. Thus, READ-Pro can also be used to train leaders on the fundamentals associated with engagement area development.http://archive.org/details/realtimeengageme109459775Captain, United States ArmyApproved for public release; distribution is unlimited
Macroecology and Sociobiology of Humans and other Mammals
Despite being the most studied species on the planet, ecologists typically do not study humans the same way we study other organisms. My Ph.D. thesis contributes to scientific development in two ways: i) synthesizing our understand of the inter and intraspecific variation in social behavior in an understudied rodent lineage, the caviomorphs, providing a comparative context to understand social evolution in general, and 2) developing a macroecological approach to understand the metabolic trajectory of the human species. Through comparative analysis, chapter 2 synthesizes the available information on the diversity of sociality in the caviomorph rodents, both within and across species. Studies and theory derived from better-studied mammalian taxa establish an integrative and comparative framework from which to examine social systems in caviomorphs. We synthesize the literature to evaluate variation in space use, group size, mating systems, and parental care strategies in caviomorphs in the context of current hypotheses. We highlight unique aspects of caviomorph biology and offer potentially fruitful lines for future research both at the inter and intraspecific levels. We can gain unique insights into the ecological drivers and evolutionary significance of diverse animal societies by studying this diverse taxon. Chapter 3 outlines core ecological principles that should be integral to a science of sustainability: 1) physical conservation laws govern the flows of energy and materials between human systems and the environment, 2) smaller systems are connected by these flows to larger systems in which they are embedded, 3) global constraints ultimately limit flows at smaller scales. Over the past few decades, decreasing per-capita rates of consumption of petroleum, phosphate, agricultural land, fresh water, fish, and wood indicate that the growing human population has surpassed the capacity of the Earth to supply enough of these essential resources to sustain even the current population and level of socioeconomic development. Chapter 4 applies a socio-metabolic perspective of the urban transition coupled with empirical examination of cross-country data spanning decades. It highlights the central role of extra-metabolic energy in global urbanization and the coinciding transition from resource extraction to industrial and service economies. The global urban transition from resource producers in rural areas, to industrial and service employment in urban systems is fuelled by supplementing extra-metabolic energy in the form of fossil fuels for decreasing human and animal labor. Collectively, I hope this work demonstrates the utility of comparative analysis and synthesis in understanding the evolutionary ecology of sociality and the power of a macroecological approach in understanding the metabolic ecology and trajectory of the human species
Community Identity: Place and the South Knoxville Waterfront
âWith the loss of tactility and the scale and details crafted for the human body and hand, our structures become repulsively flat, sharp-edged, immaterial, and unrealâ (Holl 29). Our built environment is full of constructs which are unsuccessful on a number of levels proving why it is critical to concentrate on a sense of place and identity. A great place is described as one where people gravitate towards, a place for everyone, something that is memorable, and a space which evokes a story (Placemaking Is...). South Knoxville, Tennessee, the selected site of this thesis, will test the concept of place and identity with its rich history, communal feel, and distinct character. The neighborhoods, proximity to the waterfront, view-sheds, and the people are just a few examples of what makes South Knoxville a great place. This thesis responds to a variety of users, scales, and representative elements of place present in South Knoxville, all while understanding the forces that challenge place and identity, whether they be spatial, social, economic, or natural. Three goals which drive this thesis include highlighting the identity of South Knoxville, creating public space at the Mid River section of South Knoxville, and connecting the working-class neighborhoods to the heart of the South Knoxville Waterfront which have all been under attack by poor planning and development.
South Knoxville, once full of vibrant public places with a thriving main street, began to have its identity compromised with industry and businesses that settled within proximity of the river and major roadways which run through it. The Baptist Hospital complex once at the head and center of South Knoxville, situated between two bridges, was the single most detracting element of South Knoxvilleâs identity and proposed redevelopment is no different. Precious land was consumed for large scale development, neighborhoods were and to this date are severed, and a once vibrant identity was comprised. South Knoxvilleâs tactility, scale, and details dramatically have transformed over time, thus presenting the challenge to reinvigorate the sense of place and identity at the most critical point on the South Knoxville Waterfront
Investigating subscale differences among race and language groups on the Occupational Personality Profile
Our purpose in this study was to determine whether results of the subscales of the Occupational Personality Profile (OPP) are comparable among various race and language groups. The sample consisted of 234 individuals, who had applied for management positions in various government institutions. The sample was divided into African and white individuals from different language backgrounds. Analyses revealed acceptable reliability coefficients on most of the subscales of the OPP. Significant differences among means were however found on a number of the subscales. The practical implications of these findings for employment testing and adverse impact are discussed
Design and experimental study of thermal control system for AMS cryocoolers
The Alpha Magnetic Spectrometer (AMS) is an instrument for the international scientific experiment, composed of six detectors and 650 micro-electronics. The objective of AMS experiment is to search for dark matter and anti-matter in space. In this paper, the thermal control system for AMS cryocoolers is designed, analyzed and experimentally studied. Using loop heat pipes (LHPs) as the main heat dissipation component, the thermal control system has sufficient heat dissipation capability to prevent the cryocoolers from over temperature (+40°C) in hot environment, meanwhile to ensure temperatures of the cryocoolers higher than their lower limit (â20°C) in cold environment. Experiment results show that the thermal control system for AMS cryocoolers functions stably satisfying design specification.Major Project of Technology Transfer of Shandong Province (Grant 2009ZHZX1A1105
Extra-metabolic energy use and the rise in human hyper-density
Humans, like all organisms, are subject to fundamental biophysical laws. Van Valen predicted that, because of zero-sum dynamics, all populations of all species in a given environment flux the same amount of energy on average. Damuthâs âenergetic equivalence ruleâ supported Van ValenÂŽs conjecture by showing a tradeoff between few big animals per area with high individual metabolic rates compared to abundant small species with low energy requirements. We use metabolic scaling theory to compare variation in densities and individual energy use in human societies to other land mammals. We show that hunter-gatherers occurred at densities lower than the average for a mammal of our size. Most modern humans, in contrast, concentrate in large cities at densities up to four orders of magnitude greater than hunter-gatherers, yet consume up to two orders of magnitude more energy per capita. Today, cities across the globe flux greater energy than net primary productivity on a per area basis. This is possible by importing enormous amounts of energy and materials required to sustain hyper-dense, modern humans. The metabolic rift with nature created by modern cities fueled largely by fossil energy poses formidable challenges for establishing a sustainable relationship on a rapidly urbanizing, yet finite planet
Diminishing Opportunities for Sustainability of Coastal Cities in the Anthropocene: A Review
The world is urbanizing most rapidly in tropical to sub-temperate areas and in coastal zones. Climate change along with other global change forcings will diminish the opportunities for sustainability of cities, especially in coastal areas in low-income countries. Climate forcings include global temperature and heatwave increases that are expanding the equatorial tropical belt, sea-level rise, an increase in the frequency of the most intense tropical cyclones, both increases and decreases in freshwater inputs to coastal zones, and increasingly severe extreme precipitation events, droughts, freshwater shortages, heat waves, and wildfires. Current climate impacts are already strongly influencing natural and human systems. Because of proximity to several key warming variables such as sea-level rise and increasing frequency and intensity of heatwaves, coastal cities are a leading indicator of what may occur worldwide. Climate change alone will diminish the sustainability and resilience of coastal cities, especially in the tropical-subtropical belt, but combined with other global changes, this suite of forcings represents an existential threat, especially for coastal cities. Urbanization has coincided with orders of magnitude increases in per capita GDP, energy use and greenhouse gas emissions, which in turn has led to unprecedented demand for natural resources and degradation of natural systems and more expensive infrastructure to sustain the flows of these resources. Most resources to fuel cities are extracted from ex-urban areas far away from their point of final use. The urban transition over the last 200 years is a hallmark of the Anthropocene coinciding with large surges in use of energy, principally fossil fuels, population, consumption and economic growth, and environmental impacts such as natural system degradation and climate change. Fossil energy enabled and underwrote Anthropocene origins and fueled the dramatic expansion of modern urban systems. It will be difficult for renewable energy and other non-fossil energy sources to ramp up fast enough to fuel further urban growth and maintenance and reverse climate change all the while minimizing further environmental degradation. Given these trajectories, the future sustainability of cities and urbanization trends, especially in threatened areas like coastal zones in low-income countries in the tropical to sub-tropical belt, will likely diminish. Adaptation to climate change may be limited and challenging to implement, especially for low-income countries
A Constraint-based model of Dynamic Island Biogeography: environmental history and species traits predict hysteresis in populations and communities
A Constraint-based model of Dynamic Island Biogeography: environmental history and species traits predict hysteresis in populations and communities We present a conceptual model that shows how hysteresis can emerge in dynamic island systems given simple constraints on trait-mediated processes. Over time, many islands cycle between phases of increasing and decreasing size and connectivity to a mainland species pool. As these phases alternate, the dominant process driving species composition switches between colonization and extinction. Both processes are mediated by interactions between organismal traits and environmental constraints: colonization probability is affected by a speciesâ ability to cross the intervening matrix between a population source and the island; population persistence (or extinction) is driven by the minimum spatial requirements for sustaining an isolated population. Because different suites of traits often mediate these two processes, similar environmental conditions can lead to differences in species compositions at two points of time. Thus, the Constraint-based model of Dynamic Island Biogeography (C-DIB) illustrates the possible role of hysteresisâthe dependency of outcomes not only on the current system state but also the systemâs history of environmental changeâin affecting populations and communities in insular systems. The model provides a framework upon which additional considerations of lag times, biotic interactions, evolution, and other processes can be incorporated. Importantly, it provides a testable framework to study the physical and biological constraints on populations and communities across diverse taxa, scales, and systems
Optimized diamond inverted nanocones for enhanced color center to fiber coupling
Nanostructures can be used for boosting the light outcoupling of color
centers in diamond; however, the fiber coupling performance of these
nanostructures is rarely investigated. Here, we use a finite element method for
computing the emission from color centers in inverted nanocones and the overlap
of this emission with the propagation mode in a single-mode fiber. Using
different figures of merit, the inverted nanocone parameters are optimized to
obtain maximal fiber coupling efficiency, free-space collection efficiency, or
rate enhancement. The optimized inverted nanocone designs show promising
results with 66% fiber coupling or 83% free-space coupling efficiency at the
tin-vacancy center zero-phonon line wavelength of 619 nm. Moreover, when
evaluated for broadband performance, the optimized designs show 55% and 76% for
fiber coupling and free-space efficiencies respectively, for collecting the
full tin-vacancy emission spectrum at room temperature. An analysis of
fabrication insensitivity indicates that these nanostructures are robust
against imperfections. For maximum emission rate into a fiber mode, a design
with a Purcell factor of 2.34 is identified. Finally, possible improvements
offered by a hybrid inverted nanocone, formed by patterning into two different
materials, are investigated, and increases the achievable fiber coupling
efficiency to 71%.Comment: The following article has been accepted by Applied Physics Letters.
After it is published, it will be found at https://doi.org/10.1063/5.005033
Effect of exenatide on heart rate and blood pressure in subjects with type 2 diabetes mellitus: a double-blind, placebo-controlled, randomized pilot study
<p>Abstract</p> <p>Background</p> <p>Cardiovascular effects of glucose-lowering agents are of increasing interest. Our aim was to assess the effects of the glucagon-like peptide-1 receptor agonist exenatide on heart rate (HR) and blood pressure (BP) in subjects with type 2 diabetes mellitus (T2DM).</p> <p>Methods</p> <p>In this double-blind, placebo-controlled trial, subjects with T2DM on metformin and/or a thiazolidinedione were randomized to receive exenatide (5 Όg for 4 weeks followed by 10 Όg) or placebo BID for 12 weeks. Heart rate and BP were assessed with 24-hour ambulatory BP monitoring. The primary measure was change from baseline in mean 24-hour HR.</p> <p>Results</p> <p>Fifty-four subjects (28 exenatide, 26 placebo) were randomized and comprised the intent-to-treat population. Baseline values (exenatide and placebo) were (mean ± SE) 74.4 ± 2.1 and 74.5 ± 1.9 beats/minute for HR, 126.4 ± 3.2 and 119.9 ± 2.8 mm Hg for systolic BP (SBP), and 75.2 ± 2.1 and 70.5 ± 2.0 mm Hg for diastolic BP (DBP). At 12 weeks, no significant change from baseline in 24-hour HR was observed with exenatide or placebo (LS mean ± SE, 2.1 ± 1.4 versus -0.7 ± 1.4 beats/minute, respectively; between treatments, p = 0.16). Exenatide therapy was associated with trends toward lower 24-hour, daytime, and nighttime SBP; changes in DBP were similar between groups. No changes in daytime or nighttime rate pressure product were observed. With exenatide, body weight decreased from baseline by -1.8 ± 0.4 kg (p < 0.0001; treatment difference -1.5 ± 0.6 kg, p < 0.05). The most frequently reported adverse event with exenatide was mild to moderate nausea.</p> <p>Conclusions</p> <p>Exenatide demonstrated no clinically meaningful effects on HR over 12 weeks of treatment in subjects with T2DM. The observed trends toward lower SBP with exenatide warrant future investigation.</p> <p>Trial registration</p> <p>NCT00516074</p
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