2,748 research outputs found

    Does Higher Education Provide the Necessary Skills and Competencies to Succeed in the Job Market and Life?

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    There is a crisis in higher education. One troublesome issue is the sharp drop in higher education enrollments as well as the decline in the number of colleges in the United States. There is evidence that some college degrees are not worth the time and the money, and students would have earned more had they joined the workforce immediately after graduating high school. The authors discuss some of the problems and posit that some higher education institutions in the United States have done a poor job of teaching crucial skills, including critical thinking, ethical thinking, collaboration skills, and character development. The most vital competency of all might be inculcating in students a passion for lifelong learning, which is necessary to develop the ability to adapt swiftly to changing business conditions. Without these skills, it should be no surprise that there has been a disconnect between higher education and employability

    Tomographic inversion for sediment parameters in shallow water

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    This article discusses inversions for bottom geoacoustic properties using broadband acoustic signals obtained from explosive sources. The experimental data used for the inversions are SUS charge explosions acquired on a vertical hydrophone array during the Shelf Break Primer Experiment conducted south of New England in the Middle Atlantic Bight in August 1996. The SUS signals were analyzed for their time-frequency behavior using wavelets. The group speed dispersion curves were obtained from the wavelet scalogram of the SUS signals. A genetic algorithm (GA) was used for the inversion of sound speeds in the water column and compressional wave speeds in the sediment layers. The variations in the sound speeds in the water column were represented using empirical orthogonal functions (EOFs). A range-independent normal mode routine was used to construct the replica fields corresponding to the parameters. Comparison of group speeds for modes 1 to 9 and for a range of frequencies 8 to 200 Hz was used to arrive at the best parameter fit. An efficient hybrid optimization scheme using the GA and a Levenberg–Marquardt algorithm is presented. Linear perturbation methods were also used to “fine tune” the inversions and to obtain resolution and variance estimates. Analysis was also done to compute the degree of convergence of each of the parameters by explicitly calculating the Hessian matrices numerically. A posteriori estimation of mean and covariance was also done to obtain error estimates. Group speeds for the inverted sound speed fields provide an excellent match to the experimental data. The inverted sediment compressional speed profile compares well with in situ measurements

    The Structure At 198 K Of (1R,5R,15R,16R)-5-Isopropenyl-2-Methyl-1(N-(Trans-2-Phenylcyclohexyloxyc Arbonyl)Amino)-2-Cyclohexene

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    trans-2-Phenylcyclohexyl N-(5-isopropenyl-2-methyl-2-cyclohexan-1-yl)carbamate, C23H31NO2, M(r) = 353.50, orthorhombic, P2(1)2(1)2(1), a = 8.813 (2), b = 9.043 (2), c = 25.643 (5) angstrom, V = 2043.6 (8) angstrom 3, Z = 4, D(x) = 1.15 g cm-3 (198 K), Mo K-alpha radiation, lambda = 0.7107 angstrom, mu = 0.6734 cm-1, F(000) = 768, T = 198 K, R = 0.0547 for 1772 reflections [F(o) greater-than-or-equal-to 4-sigma-(F(o))]. Molecules are H-bonded into infinite columns parallel to a. The H bond involves the NH group and the carbonyl O atom of the carbamate moiety with relevant parameters: N11-H11...O13 (related by 1/2 + x, 1/2 - y, - z); N...O 2.910 (5), H...O 2.11 (5) angstrom, N-H...O 159 (4)-degrees.Robert A. Welch Foundation (F-626)National Institutes of Health (GM 31750)ChemistryBiochemistr

    South China Sea internal tide/internal waves-impact on the temporal variability of horizontal array gain at 276 Hz

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    Author Posting. © IEEE, 2004. This article is posted here by permission of IEEE for personal use, not for redistribution. The definitive version was published in IEEE Journal of Oceanic Engineering 29 (2004): 1292-1307, doi:10.1109/JOE.2004.836794.The temporal variability of the spatial coherence of an acoustic signal received on a bottomed horizontal array has been calculated for 276-Hz narrow-band signals. A conventional plane wave beamformer was applied to the received signals. The temporal variability of the array's omnipower, beam power, and array gain are related to variability in the sound-speed field. The spectral characteristics of array omnipower are nonstationary and changed as the spectral characteristics of the temperature field varied. The array omnipower and beam-power variability tracked each other in time and varied by as much as 15 dB over time intervals as short as 7 min. Array gain varied up to 5 dB and usually tracked the omnipower variability. A contiguous 24-h section of data is discussed in detail. This data section is from a time period during which the high-frequency fluid dynamic perturbation of the sound-speed field was of smaller amplitude than other sections of the 16-d data set. Consequently, this section of data sets an upper bound for the realizable array gain. The temporal variability of array gain and spatial coherence at times appears to be correlated with environmental perturbation of the sound-speed field, but are also correlated with changes in the signal-to-noise ratio. The data was acquired during the Office of Naval Research's South China Sea Asian Seas International Acoustics Experiment. The 465-m 32-channel horizontal array was placed on the bottom in 120 m of water at the South China Sea shelf break. The acoustic source was moored in 114 m of water /spl sim/19 km from the receiving array.This work was supported by the Office of Naval Research

    Shelf-edge frontal structure in the central East China Sea and its impact on low-frequency acoustic propagation

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    Author Posting. © IEEE, 2004. This article is posted here by permission of IEEE for personal use, not for redistribution. The definitive version was published in IEEE Journal of Oceanic Engineering 29 (2004): 1011-1031, doi:10.1109/JOE.2004.840842.Two field programs, both parts of the Asian Seas International Acoustics Experiment (ASIAEX), were carried out in the central East China Sea (28 to 30 N, 126 30 to 128 E) during April 2000 and June 2001. The goal of these programs was to study the interactions between the shelf edge environment and acoustic propagation at a wide range of frequencies and spatial scales. The low-frequency across-slope propagation was studied using a synthesis of data collected during both years including conductivity- temperature-depth (CTD) and mooring data from 2000, and XBT, thermistor chain, and wide-band source data from 2001. The water column variability during both years was dominated by the Kuroshio Current flowing from southwest to northeast over the continental slope. The barotropic tide was a mixed diurnal/semidiurnal tide with moderate amplitude compared to other parts of the Yellow and East China Sea. A large amplitude semidiurnal internal tide was also a prominent feature of the data during both years. Bursts of high-frequency internal waves were often observed, but these took the form of internal solitons only once, when a rapid off-shelf excursion of the Kuroshio coincided with the ebbing tide. Two case studies in the acoustic transmission loss (TL) over the continental shelf and slope were performed. First, anchor station data obtained during 2000 were used to study how a Kuroshio warm filament on the shelf induced variance in the transmission loss (TL) along the seafloor in the NW quadrant of the study region. The corresponding modeled single-frequency TL structure explained the significant fine-scale variability in time primarily by the changes in the multipath/multimode interference pattern. The interference was quite sensitive to small changes in the phase differences between individual paths/modes induced by the evolution of the warm filament. Second, the across-slope sound speed sections from 2001 were used to explain the observed phenomenon of abrupt signal attenuation as the transmission range lengthened seaward across the continental shelf and slope. This abrupt signal degradation was caused by the Kuroshio frontal gradients that produced an increasingly downward-refracting sound-speed field seaward from the shelf break. This abrupt signal dropout was explained using normal mode theory and was predictable and source depth dependent. For a source located above the turning depth of the highest-order shelf-trapped mode, none of the propagating modes on the shelf were excited, causing total signal extinction on the shelf

    Comparison of Histidine-Tryptophan-Ketoglutarate and University of Wisconsin Preservation in Renal Transplantation

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72258/1/j.1600-6143.2007.02065.x.pd

    Epidemiology, genetics, and subtyping of preserved ratio impaired spirometry (PRISm) in COPDGene.

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    BackgroundPreserved Ratio Impaired Spirometry (PRISm), defined as a reduced FEV1 in the setting of a preserved FEV1/FVC ratio, is highly prevalent and is associated with increased respiratory symptoms, systemic inflammation, and mortality. Studies investigating quantitative chest tomographic features, genetic associations, and subtypes in PRISm subjects have not been reported.MethodsData from current and former smokers enrolled in COPDGene (n = 10,192), an observational, cross-sectional study which recruited subjects aged 45-80 with ≥10 pack years of smoking, were analyzed. To identify epidemiological and radiographic predictors of PRISm, we performed univariate and multivariate analyses comparing PRISm subjects both to control subjects with normal spirometry and to subjects with COPD. To investigate common genetic predictors of PRISm, we performed a genome-wide association study (GWAS). To explore potential subgroups within PRISm, we performed unsupervised k-means clustering.ResultsThe prevalence of PRISm in COPDGene is 12.3%. Increased dyspnea, reduced 6-minute walk distance, increased percent emphysema and decreased total lung capacity, as well as increased segmental bronchial wall area percentage were significant predictors (p-value <0.05) of PRISm status when compared to control subjects in multivariate models. Although no common genetic variants were identified on GWAS testing, a significant association with Klinefelter's syndrome (47XXY) was observed (p-value < 0.001). Subgroups identified through k-means clustering include a putative "COPD-subtype", "Restrictive-subtype", and a highly symptomatic "Metabolic-subtype".ConclusionsPRISm subjects are clinically and genetically heterogeneous. Future investigations into the pathophysiological mechanisms behind and potential treatment options for subgroups within PRISm are warranted.Trial registrationClinicaltrials.gov Identifier: NCT000608764

    Overview of results from the Asian Seas International Acoustics Experiment in the East China Sea

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    Author Posting. © IEEE, 2004. This article is posted here by permission of IEEE for personal use, not for redistribution. The definitive version was published in IEEE Journal of Oceanic Engineering 29 (2004): 920-928, doi:10.1109/JOE.2005.843159.The Asian Seas International Acoustics Experiment (ASIAEX) included two major field programs, one in the South China Sea and the other in the East China Sea (ECS). This paper presents an overview of research results from ASIAEX ECS conducted between May 28 and June 9, 2001. The primary emphasis of the field program was shallow-water acoustic propagation, focused on boundary interaction and geoacoustic inversion. The study area's central point was located at 29/spl deg/ 40.67'N, 126/spl deg/ 49.39'E, which is situated 500 km east of the Chinese coastline off Shanghai. The acoustic and supporting environmental measurements are summarized, along with research results to date, and references to papers addressing specific issues in more detail are given.This work was supported by the U.S. Office of Naval Research under Code 321 OA and by sponsoring agencies within China. Primary guidance and sponsorship for ASIAEX East China Sea came from the U.S. Office of Naval Research and significant financial support was also received from sponsoring agencies within China
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