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Denton, TX, United States

The University of North Texas , based in Denton, is a public institution of higher education and research committed to a wide array of science, engineering fields, liberal arts, fine arts, performing arts, humanities, public policy, and graduate professional education. Ten colleges, two schools, an early admissions math and science academy for exceptional high-school-age students from across the state, and a library system comprise the university. Its research is driven by about 34 doctoral degree programs. During the 2013–2014 school year, the university had a budget of $865 million, of which $40 million was allocated for research. North Texas was founded as a nonsectarian, coeducational, private teachers college in 1890; and, as a collaborative development in response to enrollment growth and public demand, its trustees ceded control to the state in 1899. In 1901, North Texas was formally adopted by the State. Wikipedia.

Izrailev F.M.,Autonomous University of Puebla | Krokhin A.A.,University of North Texas | Makarov N.M.,Autonomous University of Puebla
Physics Reports | Year: 2012

This review presents a unified view on the problem of Anderson localization in one-dimensional weakly disordered systems with short-range and long-range statistical correlations in random potentials. The following models are analyzed: the models with continuous potentials, the tight-binding models of the Anderson type, and various Kronig-Penney models with different types of perturbations. Main attention is paid to the methods of obtaining the localization length in dependence on the controlling parameters of the models. Specific interest is in an emergence of effective mobility edges due to certain long-range correlations in a disorder. The predictions of the theoretical and numerical analysis are compared to recent experiments on microwave transmission through randomly filled waveguides. © 2011 Elsevier B.V..

Fry M.,University of North Texas
Energy Policy | Year: 2013

Newly accessible shale deposits and other unconventional sources of natural gas have dramatically increased global gas reserves and are regarded as major future energy sources. Shale gas drilling began in Texas and is expanding throughout the U.S. and globally. In Texas and other regions, large population centers overlie these deposits. As a result, city residents increasingly come into contact with extraction activities. The proximity of drilling activities to residential areas raises a number of concerns, including noise, dust and emissions hazards, public safety, diminished quality of life, and effects on neighborhood aesthetics and property values. Cities in Texas address these concerns through setback ordinances that regulate the distance between gas wells and residences, schools, floodplains, etc. Although the state of Texas permits drilling 200. ft (61. m) from residences, many municipalities in the Dallas-Fort Worth Metroplex (DFW) have established longer setback distances. This paper analyzes the purpose and basis for setback distances among 26 municipalities in DFW. Findings show that there is no uniform setback distance, distances have increased over time, and, rather than technically-based, setbacks are political compromises. For policy makers confronted with urban shale gas drilling, deriving setback distances from advanced emissions monitoring could decrease setback distance ambiguity. © 2013 Elsevier Ltd.

Burggren W.W.,University of North Texas
Journal of Experimental Biology | Year: 2015

Epigenetic studies of both intragenerational and transgenerational epigenetic phenotypic modifications have proliferated in the last few decades. However, the strong reductionist focus on mechanism that prevails in many epigenetic studies to date has diverted attention away what might be called the 'dynamics' of epigenetics and its role in comparative biology. Epigenetic dynamics describes how both transgenerational and intragenerational epigenetic phenotypic modifications change in non-linear patterns over time. Importantly, a dynamic perspective suggests that epigenetic phenomena should not be regarded as 'digital' (on-off), in which a modified trait necessarily suddenly disappears between one generation and the next. Rather, dynamic epigenetic phenomena may be better depicted by graded, time-related changes that can potentially involve the 'washout' of modified phenotype both within and across generations. Conceivably, an epigenetic effect might also 'wash-in' over multiple generations, and there may be unexplored additive effects resulting from the pressures of environmental stressors that wax, wane and then wax again across multiple generations. Recognition of epigenetic dynamics is also highly dependent on the threshold for detection of the phenotypic modification of interest, especially when phenotypes wash out or wash in. Thus, studies of transgenerational epigenetic effects (and intragenerational effects, for that matter) that search for persistence of the phenomenon are best conducted with highly sensitive, precise quantitative methods. All of the scenarios in this review representing epigenetic dynamics are possible and some even likely. Focused investigations that concentrate on the time course will reveal much about both the impact and mechanisms of epigenetic phenomena. © 2015. Published by The Company of Biologists Ltd | The Journal of Experimental Biology.

Burggren W.W.,University of North Texas
Journal of Experimental Biology | Year: 2014

Considerable variation is inherent both within and between comparative physiological data sets. Known sources for such variation include diet, gender, time of day and season of experiment, among many other factors, but a meta-analysis of physiological studies shows that surprisingly few studies report controlling for these factors. In fact, less than 3% of comparative physiological papers mention epigenetics. However, our understanding of epigenetic influences on physiological processes is growing rapidly, and it is highly likely that epigenetic phenomena are an additional 'hidden' source of variation, particularly in wild-caught specimens. Recent studies have shown epigenetic inheritance of commonly studied traits such as metabolic rate (water fleas Daphnia magna; emu, Dromaius novaellandiae), hypoxic tolerance, cardiac performance (zebrafish, Danio rerio), as well as numerous morphological effects. The ecological and evolutionary significance of such epigenetic inheritance is discussed in a comparative physiological context. Finally, against this context of epigenetic inheritance of phenotype, this essay also provides a number of caveats and warnings regarding the interpretation of transgenerational phenotype modification as a true epigenetic phenomenon. Parental effects, sperm storage, multiple paternity and direct gamete exposure can all be confounding factors. Epigenetic inheritance may best be studied in animal models that can be maintained in the laboratory over multiple generations, to yield parental stock that themselves are free of epigenetic effects from the historical experiences of their parents. © 2014. Published by The Company of Biologists Ltd | The Journal of Experimental Biology.

Ayre B.G.,University of North Texas
Molecular Plant | Year: 2011

Sucrose is the principal product of photosynthesis used for the distribution of assimilated carbon in plants. Transport mechanisms and efficiency influence photosynthetic productivity by relieving product inhibition and contribute to plant vigor by controlling source/sink relationships and biomass partitioning. Sucrose is synthesized in the cytoplasm and may move cell to cell through plasmodesmata or may cross membranes to be compartmentalized or exported to the apoplasm for uptake into adjacent cells. As a relatively large polar compound, sucrose requires proteins to facilitate efficient membrane transport. Transport across the tonoplast by facilitated diffusion, antiport with protons, and symport with protons have been proposed; for transport across plasma membranes, symport with protons and a mechanism resembling facilitated diffusion are evident. Despite decades of research, only symport with protons is well established at the molecular level. This review aims to integrate recent and older studies on sucrose flux across membranes with principles of whole-plant carbon partitioning. © 2011 The Author.

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