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Institution

University of Houston

EducationHouston, Texas, United States
About: University of Houston is a education organization based out in Houston, Texas, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 23074 authors who have published 53903 publications receiving 1641968 citations.


Papers
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Journal ArticleDOI
TL;DR: Results suggest that although face-name training, spaced retrieval, and cognitive stimulation may produce small gains in learning personal information and on a measure of attention, improvement does not generalize to overall neuropsychologic functioning or patient quality of life.
Abstract: The efficacy of a cognitive intervention consisting of training in face-name associations, spaced retrieval, and cognitive stimulation was tested in a sample of 37 patients (16 men, 21 women) with probable Alzheimer disease (AD). Patients with AD were randomly assigned to receive either the cognitive intervention or a mock (placebo) intervention for 5 weeks. The placebo group then crossed over to receive the intervention. During the intervention, AD patients showed significant improvement in recall of personal information, face-name recall, and performance on the Verbal Series Attention Test. Improvement did not generalize to additional neuropsychologic measures of dementia severity, verbal memory, visual memory, word generation, or motor speed, or to caregiver-assessed patient quality of life. Results suggest that although face-name training, spaced retrieval, and cognitive stimulation may produce small gains in learning personal information and on a measure of attention, improvement does not generalize to overall neuropsychologic functioning or patient quality of life.

247 citations

Journal ArticleDOI
TL;DR: An improved representation of NMVOCs in a global 3-D chemical transport model (GEOS-Chem) is used and it is shown that it can simulate PAN observations from aircraft campaigns worldwide and is very sensitive to plume chemistry and plume rise.
Abstract: . Peroxyacetyl nitrate (PAN) formed in the atmospheric oxidation of non-methane volatile organic compounds (NMVOCs) is the principal tropospheric reservoir for nitrogen oxide radicals (NOx = NO + NO2). PAN enables the transport and release of NOx to the remote troposphere with major implications for the global distributions of ozone and OH, the main tropospheric oxidants. Simulation of PAN is a challenge for global models because of the dependence of PAN on vertical transport as well as complex and uncertain NMVOC sources and chemistry. Here we use an improved representation of NMVOCs in a global 3-D chemical transport model (GEOS-Chem) and show that it can simulate PAN observations from aircraft campaigns worldwide. The immediate carbonyl precursors for PAN formation include acetaldehyde (44% of the global source), methylglyoxal (30%), acetone (7%), and a suite of other isoprene and terpene oxidation products (19%). A diversity of NMVOC emissions is responsible for PAN formation globally including isoprene (37%) and alkanes (14%). Anthropogenic sources are dominant in the extratropical Northern Hemisphere outside the growing season. Open fires appear to play little role except at high northern latitudes in spring, although results are very sensitive to plume chemistry and plume rise. Lightning NOx is the dominant contributor to the observed PAN maximum in the free troposphere over the South Atlantic.

247 citations

Journal ArticleDOI
TL;DR: In this paper, an algorithm for the microgrid planning as an alternative to the co-optimization of generation and transmission expansion planning in electric power systems is presented, which aims to minimize the total system planning cost comprising investment and operation costs of local microgrids, the cooptimized planning of large generating units and transmission lines, and the expected cost of unserved energy.
Abstract: This paper presents an algorithm for the microgrid planning as an alternative to the co-optimization of generation and transmission expansion planning in electric power systems. The integration of microgrids in distribution systems will offer a decentralized control of local resources for satisfying the network reliability and the power quality required by local loads. The objective in this paper is to minimize the total system planning cost comprising investment and operation costs of local microgrids, the co-optimized planning of large generating units and transmission lines, and the expected cost of unserved energy. The cost of unserved energy reflects the cost of load shedding which is added to the objective function for reliability considerations. The microgrid-based co-optimization planning problem is decomposed into a planning problem and annual reliability subproblem. The optimal integer planning decisions calculated in the planning problem will be examined against the system reliability limits in the subproblem and the planning decisions will be revised using proper feasibility cuts if the annual reliability limits are violated. Numerical simulations demonstrate the effectiveness of the proposed microgrid-based co-optimization planning in power systems and explore the economic and reliability merits of microgrid planning as compared to grid-based generation and transmission upgrades.

247 citations

Journal ArticleDOI
TL;DR: These cross-sectional data show a general pattern of ocular growth, no change in corneal power, and crystalline lens thinning and flattening between the ages of 6 and 14 years, with girls tended to have steeper corneas, stronger crystalline lenses, and shorter eyes compared with boys.
Abstract: :Purpose.To describe the refractive error and ocular components of a large group of school-aged children as a function of age and gender.Methods.In this report, we describe the refractive error and ocular components of 2583 school-aged children (49.3% girls, overall mean [±SD] age 10.0 ± 2.3

247 citations

Journal ArticleDOI
TL;DR: In this article, the authors recast the Gassmann's relations in terms of a porosity-dependent normalized modulus and a simplified gain function, and provided upper and lower bounds of the fluid-saturation effect on bulk modulus.
Abstract: Gassmann’s (1951) equations commonly are used to predict velocity changes resulting from different porefluid saturations. However, the input parameters are often crudely estimated, and the resulting estimates of fluid effects can be unrealistic. In rocks, parameters such as porosity, density, and velocity are not independent, and values must be kept consistent and constrained. Otherwise, estimating fluid substitution can result in substantial errors. We recast the Gassmann’s relations in terms of a porosity-dependent normalized modulus Kn and the fluid sensitivity in terms of a simplified gain function G. General Voigt-Reuss bounds and critical porosity limits constrain the equations and provide upper and lower bounds of the fluid-saturation effect on bulk modulus. The “D” functions are simplified modulus-porosity relations that are based on empirical porosity-velocity trends. These functions are applicable to fluid-substitution calculations and add important constraints on the results. More importantly, the simplified Gassmann’s relations provide better physical insight into the significance of each parameter. The estimated moduli remain physical, the calculations are more stable, and the results are more realistic.

246 citations


Authors

Showing all 23345 results

NameH-indexPapersCitations
Matthew Meyerson194553243726
Gad Getz189520247560
Eric Boerwinkle1831321170971
Pulickel M. Ajayan1761223136241
Zhenan Bao169865106571
Marc Weber1672716153502
Steven N. Blair165879132929
Martin Karplus163831138492
Dongyuan Zhao160872106451
Xiang Zhang1541733117576
Jan-Åke Gustafsson147105898804
James M. Tour14385991364
Guanrong Chen141165292218
Naomi J. Halas14043582040
Antonios G. Mikos13869470204
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
2023111
2022440
20213,031
20203,072
20192,806
20182,568