Matching Items (43,917)
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Description

Indigenous populations are generally reported to suffer greater active tuberculosis (TB) disease burden. The objective of this study was to examine ecological associations between cases of active adult and pediatric TB reported from 2002 to 2004 and community

Indigenous populations are generally reported to suffer greater active tuberculosis (TB) disease burden. The objective of this study was to examine ecological associations between cases of active adult and pediatric TB reported from 2002 to 2004 and community characteristics in indigenous communities of the Paraguayan Chaco. Adult and pediatric models were examined by negative binomial and Poisson GLM regression, respectively. Active TB prevalence in indigenous people was eight times higher than the nonindigenous population. Communities with a health post were more than twice as likely to report active adult TB (RR = 2.07, 95% confidence interval (CI) [1.14–3.83], and p < 0.05). Each additional average year of education in the community was associated with nearly 50% less likelihood of active pediatric TB (RR = 0.53, 95% CI [0.38–0.73], and p < 0.001). Although nonsignificant, the presence of nonindigenous community members had a strong protective association in both the adult (RR = 0.56, 95% CI [0.30–1.03], and p = 0.6) and pediatric models (RR = 0.64, 95% CI [0.34–1.14], and p = 0.14). These results reinforce the importance of increasing epidemiologic surveillance and investigating the social determinants of TB disease among vulnerable indigenous populations.

Contributors Vansteelandt, Amanda (Author) / Hurtado, Ana (Author) / Rolon, Miriam (Author) / Rojas de Arias, Antonieta (Author) / Jara, Juan Carlos (Author) / College of Liberal Arts and Sciences (Contributor)
Created 2015-11-10
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Multilayer structures of TiO2/Ag/TiO2 have been deposited onto flexible substrates by room temperature sputtering to develop indium-free transparent composite electrodes. The effect of Ag thicknesses on optical and electrical properties and the mechanism of conduction have been discussed.

Multilayer structures of TiO2/Ag/TiO2 have been deposited onto flexible substrates by room temperature sputtering to develop indium-free transparent composite electrodes. The effect of Ag thicknesses on optical and electrical properties and the mechanism of conduction have been discussed. The critical thickness (tc) of Ag mid-layer to form a continuous conducting layer is 9.5 nm and the multilayer has been optimized to obtain a sheet resistance of 5.7 Ω/sq and an average optical transmittance of 90% at 590 nm. The Haacke figure of merit (FOM) for tc has one of the highest FOMs with 61.4 × 10-3 Ω-1/sq.

Contributors Dhar, Aritra (Author) / Alford, Terry (Author) / Department of Chemistry and Biochemistry (Contributor)
Created 2013-06-07
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Description

Tree-like structures are ubiquitous in nature. In particular, neuronal axons and dendrites have tree-like geometries that mediate electrical signaling within and between cells. Electrical activity in neuronal trees is typically modeled using coupled cable equations on multi-compartment representations,

Tree-like structures are ubiquitous in nature. In particular, neuronal axons and dendrites have tree-like geometries that mediate electrical signaling within and between cells. Electrical activity in neuronal trees is typically modeled using coupled cable equations on multi-compartment representations, where each compartment represents a small segment of the neuronal membrane. The geometry of each compartment is usually defined as a cylinder or, at best, a surface of revolution based on a linear approximation of the radial change in the neurite. The resulting geometry of the model neuron is coarse, with non-smooth or even discontinuous jumps at the boundaries between compartments. We propose a hyperbolic approximation to model the geometry of neurite compartments, a branched, multi-compartment extension, and a simple graphical approach to calculate steady-state solutions of an associated system of coupled cable equations. A simple case of transient solutions is also briefly discussed.

Created 2014-07-09
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Description

The genus Apodrosus Marshall is newly recorded for, and revised for Cuba. Nine new species are recognized as follows: Apodrosus alberti (type locality, Granma, Parque Nacional Pico Turquino), A. alternatus (type locality, Guantánamo, El Yunque), A. franklyni (type

The genus Apodrosus Marshall is newly recorded for, and revised for Cuba. Nine new species are recognized as follows: Apodrosus alberti (type locality, Granma, Parque Nacional Pico Turquino), A. alternatus (type locality, Guantánamo, El Yunque), A. franklyni (type locality, Cienfuegos, Parque Nacional Pico San Juan), A. griseus (type locality, Santiago de Cuba, Siboney-Jutici Ecological Reserve), A. mensurensis (type locality, Holguin, Parque Nacional La Mensura-Piloto), A. pseudoalternatus (type locality, Matanzas, Varahicacos), A. beckeli (type locality, Guantánamo, 8 km W. Imias), A. sandersoni (type locality, Guantánamo, Loma Lafarola), and A. zayasi (type locality, Cienfuegos, Parque Nacional Pico San Juan). A key for their identification, descriptions, summaries of natural history information and data on distributions are presented. A molecular phylogeny based on 11 species of Apodrosus from Cuba, Hispaniola and Puerto Rico is reconstructed. A sister group relationship between Polydrusus and Apodrosus is recovered with a limited sampling of the former genus. The monophyly of Apodrosus is recovered with strong support. Cuban Apodrosus are not monophyletic. Five of the six sampled Cuban species form a clade, sister to an undescribed Apodrosus species from the Dominican Republic; and, Apodrosus alternatus is sister to A. quisqueyanus Girón & Franz, 2010, a species from the Dominican Republic. Biogeographic implications for Cuban species are discussed in light of the phylogeny.

Contributors Anderson, Robert S. (Author) / Zhang, Guanyang (Author) / College of Liberal Arts and Sciences (Contributor)
Created 2017-06-12
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Description

The termites evolved eusociality and complex societies before the ants, but have been studied much less. The recent publication of the first two termite genomes provides a unique comparative opportunity, particularly because the sequenced termites represent opposite ends

The termites evolved eusociality and complex societies before the ants, but have been studied much less. The recent publication of the first two termite genomes provides a unique comparative opportunity, particularly because the sequenced termites represent opposite ends of the social complexity spectrum. Zootermopsis nevadensis has simple colonies with totipotent workers that can develop into all castes (dispersing reproductives, nest-inheriting replacement reproductives, and soldiers). In contrast, the fungus-growing termite Macrotermes natalensis belongs to the higher termites and has very large and complex societies with morphologically distinct castes that are life-time sterile. Here we compare key characteristics of genomic architecture, focusing on genes involved in communication, immune defenses, mating biology and symbiosis that were likely important in termite social evolution. We discuss these in relation to what is known about these genes in the ants and outline hypothesis for further testing.

Contributors Korb, Judith (Author) / Poulsen, Michael (Author) / Hu, Haofu (Author) / Li, Cai (Author) / Boomsma, Jacobus J. (Author) / Zhang, Guojie (Author) / Liebig, Juergen (Author) / College of Liberal Arts and Sciences (Contributor)
Created 2015-03-04
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Description

Groundwater is a common-pool resource that is subject to depletion in many places around the world as a result of increased use of irrigation and water-demanding cash crops. Where state capacity to control groundwater use is limited, collective

Groundwater is a common-pool resource that is subject to depletion in many places around the world as a result of increased use of irrigation and water-demanding cash crops. Where state capacity to control groundwater use is limited, collective action is important to increase recharge and restrict highly water-consumptive crops. We present results of field experiments in hard rock areas of Andhra Pradesh, India, to examine factors affecting groundwater use. Two nongovernmental organizations (NGOs) ran the games in communities where they were working to improve watershed and water management. Results indicate that, when the links between crop choice and groundwater depletion is made explicit, farmers can act cooperatively to address this problem. Longer NGO involvement in the villages was associated with more cooperative outcomes in the games. Individuals with more education and higher perceived community social capital played more cooperatively, but neither gender nor method of payment had a significantly effect on individual behavior. When participants could repeat the game with communication, similar crop choice patterns were observed. The games provided an entry point for discussion on the understanding of communities of the interconnectedness of groundwater use and crop choice.

Contributors Meinzen-Dick, Ruth (Author) / Chaturvedi, Rahul (Author) / Domenech, Laia (Author) / Ghate, Rucha (Author) / Janssen, Marco (Author) / Rollins, Nathan (Author) / Sandeep, K. (Author) / Julie Ann Wrigley Global Institute of Sustainability (Contributor)
Created 2016
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The Mars Science Laboratory landed in Gale crater on Mars in August 2012, and the Curiosity rover then began field studies on its drive toward Mount Sharp, a central peak made of ancient sediments. CheMin is one of

The Mars Science Laboratory landed in Gale crater on Mars in August 2012, and the Curiosity rover then began field studies on its drive toward Mount Sharp, a central peak made of ancient sediments. CheMin is one of ten instruments on or inside the rover, all designed to provide detailed information on the rocks, soils and atmosphere in this region. CheMin is a miniaturized X-ray diffraction/X-ray fluorescence (XRD/XRF) instrument that uses transmission geometry with an energy-discriminating CCD detector. CheMin uses onboard standards for XRD and XRF calibration, and beryl:quartz mixtures constitute the primary XRD standards. Four samples have been analysed by CheMin, namely a soil sample, two samples drilled from mudstones and a sample drilled from a sandstone. Rietveld and full-pattern analysis of the XRD data reveal a complex mineralogy, with contributions from parent igneous rocks, amorphous components and several minerals relating to aqueous alteration. In particular, the mudstone samples all contain one or more phyllosilicates consistent with alteration in liquid water. In addition to quantitative mineralogy, Rietveld refinements also provide unit-cell parameters for the major phases, which can be used to infer the chemical compositions of individual minerals and, by difference, the composition of the amorphous component.

Contributors Bish, David (Author) / Blake, David (Author) / Vaniman, David (Author) / Sarrazin, Philippe (Author) / Bristow, Thomas (Author) / Achilles, Cherie (Author) / Dera, Przemyslaw (Author) / Chipera, Steve (Author) / Crisp, Joy (Author) / Downs, R. T. (Author) / Farmer, Jack (Author) / Gailhanou, Marc (Author) / Ming, Doug (Author) / Morookian, John Michael (Author) / Morris, Richard (Author) / Morrison, Shaunna (Author) / Rampe, Elizabeth (Author) / Treiman, Allan (Author) / Yen, Albert (Author) / College of Liberal Arts and Sciences (Contributor)
Created 2014-10-21
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Description

The catalytic hydrogenation of nitroarenes is an environmentally benign technology for the production of anilines, which are key intermediates for manufacturing agrochemicals, pharmaceuticals and dyes. Most of the precious metal catalysts, however, suffer from low chemoselectivity when one

The catalytic hydrogenation of nitroarenes is an environmentally benign technology for the production of anilines, which are key intermediates for manufacturing agrochemicals, pharmaceuticals and dyes. Most of the precious metal catalysts, however, suffer from low chemoselectivity when one or more reducible groups are present in a nitroarene molecule. Herein we report FeOx-supported platinum single-atom and pseudo-single-atom structures as highly active, chemoselective and reusable catalysts for hydrogenation of a variety of substituted nitroarenes. For hydrogenation of 3-nitrostyrene, the catalyst yields a TOF of ~1,500 h-1, 20-fold higher than the best result reported in literature, and a selectivity to 3-aminostyrene close to 99%, the best ever achieved over platinum group metals. The superior performance can be attributed to the presence of positively charged platinum centres and the absence of Pt–Pt metallic bonding, both of which favour the preferential adsorption of nitro groups.

Contributors Wei, Haisheng (Author) / Liu, Xiaoyan (Author) / Wang, Aiqin (Author) / Zhang, Leilei (Author) / Qiao, Botao (Author) / Yang, Xiaofeng (Author) / Huang, Yanqiang (Author) / Miao, Shu (Author) / Liu, Jingyue (Author) / Zhang, Tao (Author) / College of Liberal Arts and Sciences (Contributor)
Created 2014-12-03
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Description

Ferromagnetic Heusler Co2FeAl0.5Si0.5 epitaxial thin-films have been fabricated in the L21 structure with saturation magnetizations over 1200 emu/cm3. Andreev reflection measurements show that the spin polarization is as high as 80% in samples sputtered on unheated MgO (100)

Ferromagnetic Heusler Co2FeAl0.5Si0.5 epitaxial thin-films have been fabricated in the L21 structure with saturation magnetizations over 1200 emu/cm3. Andreev reflection measurements show that the spin polarization is as high as 80% in samples sputtered on unheated MgO (100) substrates and annealed at high temperatures. However, the spin polarization is considerably smaller in samples deposited on heated substrates.

Contributors Vahidi, Mahmoud (Author) / Gifford, Jessica (Author) / Zhang, Shengke (Author) / Krishnamurthy, S. (Author) / Yu, Z. G. (Author) / Lei, Yu (Author) / Huang, Mengchu (Author) / Youngbull, Cody (Author) / Chen, Tingyong (Author) / Newman, Nathan (Author) / Ira A. Fulton Schools of Engineering (Contributor)
Created 2014-04-15
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Based on considerable neurophysiological evidence, Roy (2012) proposed the theory that localist representation is widely used in the brain, starting from the lowest levels of processing. Grandmother cells are a special case of localist representation. In this article,

Based on considerable neurophysiological evidence, Roy (2012) proposed the theory that localist representation is widely used in the brain, starting from the lowest levels of processing. Grandmother cells are a special case of localist representation. In this article, I present the theory that grandmother cells are also widely used in the brain. To support the proposed theory, I present neurophysiological evidence and an analysis of the concept of grandmother cells. Konorski (1967) first predicted the existence of grandmother cells (he called them “gnostic” neurons) - single neurons that respond to complex stimuli such as faces, hands, expressions, objects, and so on. The term “grandmother cell” was introduced by Jerry Lettvin in 1969 (Barlow, 1995).

Contributors Roy, Asim (Author) / W.P. Carey School of Business (Contributor)
Created 2013-05-24