115 research outputs found
The Relationship Between Family-Environmental Processes and Academic Achievement Among Three Hispanic Groups in the United States
The purpose of this study was to examine (1) whether differences in academic achievement exist among students of three Hispanic groups in the United States, (2) whether such differences are related to student achievement processes, and (3) whether differences in both student academic achievement and achievement processes are related to their parents\u27 background characteristics.
The three Hispanic groups of students that were studied were Puerto Rican, Cuban, and Central/South American. Two student achievement processes were examined: their time spent on homework and their educational-occupational aspirations. The three parental achievement processes investigated were their press for English, press for independence and educational-occupational aspirations for their child. Finally, two background characteristics of the parents were studied: their time residing in the United States and their level of academic attainment. The model that guided this investigation was developed from Marjoribanks\u27 (1976) Social-Environmental theory and was tested using path analysis procedures.
It was found that the proposed family environmental model could explain 56 percent of the variance in the students\u27 Reading achievement and 59 percent of the variance in their Mathematics achievement. The results showed that paternal achievement processes played a larger role than maternal processes in the academic achievement of these Hispanic students. In addition, it was found that these students\u27 educational-occupational aspirations were related to their academic achievement, and that their homework time was affected by their educational and occupational aspirations. In comparisons among the three Hispanic groups, Cuban fathers displayed significantly higher levels of press for English, press for independence and educational-occupational aspirations than Central/South American fathers. The latter fathers in turn showed higher levels of each of these three family processes than Puerto Rican fathers.
The results were interpreted as supportive of the Social-Environmental view of academic achievement and as indicative of important differences in family achievement processes among the three Hispanic groups that were studied. Educational implications for remediation programs were discussed
Enhanced field-of-view integral imaging display using multi-Köhler illumination
A common drawback in 3D integral imaging displays is the appearance of pseudoimages beyond the viewing angle. These pseudoimages appear when the light rays coming from each elemental image are not passing through the corresponding microlens, and a set of barriers must be used to avoid this flipping effect. We present a pure optical arrangement based on Köhler illumination to generate these barriers thus avoiding the pseudoimages. The proposed system does not use additional lenses to project the elemental images, so no optical aberrations are introduced. As an added benefit, Köhler illumination provides a higher contrast 3D display.This work was supported in part by the Plan Nacional I + D + I, under Grants DPI2012-32994 and ENE2013-48565-C2-2-P, Ministerio de Economía y Competitividad (Spain), and also by the Generalitat Valenciana (Spain) under Grant PROMETEOII/2014/072. The work of Ángel Tolosa was supported by the Generalitat Valenciana under IVACE Grant PROMECE 2014
Tuberculine reaction measured by infrared thermography
Setting: The infection with Mycobacterium tuberculosis gives a delayed immune response, measured by the tuberculine skin test. We present a new technique for evaluation based on automatic detection and measurement of skin temperature due to infrared emission.; Design: 34 subjects (46.8+/-16.9 years) (12/22, M/F) with suspected tuberculosis disease were examined with an IR thermal camera, 48h after tuberculin skin injection.; Results: In 20 subjects, IR analysis was positive for tuberculine test. Mean temperature of injection area was higher, around 1 degrees C, for the positive group (36.2+/-1.1 degrees C positive group; 35.1+/-1.6 degrees C negative group, p < 0.02 T test for unpaired groups).; Conclusion: IR image analysis achieves similar estimation of tuberculin reaction as the visual evaluation, based on higher temperature due to increased heat radiation from the skin lesion.Peer ReviewedPostprint (author's final draft
Long-term follow-up of transjugular intrahepatic portosystemic shunt (TIPS) with stent-graft
PURPOSEWe aimed to retrospectively evaluate the long-term clinical and patency results after the placement of transjugular intrahepatic portosystemic shunts (TIPS) using stent-graft. Many studies show the clinical results and the patency follow-up of TIPS with stent-graft in the short and medium term. However, few studies show long-term results.METHODSBetween 2002 and 2016, TIPS with stent-grafts were placed in 132 patients. The median age was 59.5 years. The median Model for End-stage Liver Disease (MELD) score was 13, and 71% were Child-Pugh B. Indications for TIPS were bleeding (83%) and ascites or hydrothorax (17%). The technical and clinical success rates were calculated, as were the rates of patency, survival and complications. The median follow-up period was 43 months.RESULTSThe technical success rate was 98%, and the clinical success rates were 85% in patients with indication for bleeding and 95% in patients with indication for ascites or hydrothorax. Primary patency did not decrease from 66% after 6 years (95% confidence interval [CI], 56.2%–75.8%) primary assisted patency remained stable at 87% after 6 years (95% CI, 77.2%–96.8%) and secondary patency did not decrease from 98% after 4 years (95% CI, 95.1%–100%). The median overall survival was 42.8 months (95% CI, 33.8–51.8 months). A total of 54 patients suffered some type of complication, minor (28 patients) or major (26 patients), during the follow-up.CONCLUSIONThe clinical success rate was high. The choice of the maximum initial limit of portosystemic gradient and the diameter of the post-TIPS shunt, together with the number of shunt reductions, are important to be able to compare results between publications. In our study, the patency rates did not decrease after 6 years; hence, long-term follow-up of these patients may not be necessary
Gaia Focused Product Release: Radial velocity time series of long-period variables
Context. The third Gaia Data Release (DR3) provided photometric time series of more than 2 million long-period variable (LPV) candidates. Anticipating the publication of full radial-velocity data planned with Data Release 4, this Focused Product Release (FPR) provides radial-velocity time series for a selection of LPV candidates with high-quality observations. Aims. We describe the production and content of the Gaia catalog of LPV radial-velocity time series, and the methods used to compute the variability parameters published as part of the Gaia FPR. Methods. Starting from the DR3 catalog of LPV candidates, we applied several filters to construct a sample of sources with high-quality radial-velocity measurements. We modeled their radial-velocity and photometric time series to derive their periods and amplitudes, and further refined the sample by requiring compatibility between the radial-velocity period and at least one of the G, GBP, or GRP photometric periods. Results. The catalog includes radial-velocity time series and variability parameters for 9614 sources in the magnitude range 6 ≲ G/mag ≲ 14, including a flagged top-quality subsample of 6093 stars whose radial-velocity periods are fully compatible with the values derived from the G, GBP, and GRP photometric time series. The radial-velocity time series contain a mean of 24 measurements per source taken unevenly over a duration of about three years. We identify the great majority of the sources (88%) as genuine LPV candidates, with about half of them showing a pulsation period and the other half displaying a long secondary period. The remaining 12% of the catalog consists of candidate ellipsoidal binaries. Quality checks against radial velocities available in the literature show excellent agreement. We provide some illustrative examples and cautionary remarks. Conclusions. The publication of radial-velocity time series for almost ten thousand LPV candidates constitutes, by far, the largest such database available to date in the literature. The availability of simultaneous photometric measurements gives a unique added value to the Gaia catalog
Crop pests and predators exhibit inconsistent responses to surrounding landscape composition
The idea that noncrop habitat enhances pest control and represents a win–win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop damage as a function of landscape composition. Our results showed that although landscape composition explained significant variation within studies, pest and enemy abundances, predation rates, crop damage, and yields each exhibited different responses across studies, sometimes increasing and sometimes decreasing in landscapes with more noncrop habitat but overall showing no consistent trend. Thus, models that used landscape-composition variables to predict pest-control dynamics demonstrated little potential to explain variation across studies, though prediction did improve when comparing studies with similar crop and landscape features. Overall, our work shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others. Future efforts to develop tools that inform farmers when habitat conservation truly represents a win–win would benefit from increased understanding of how landscape effects are modulated by local farm management and the biology of pests and their enemies
Rate and duration of hospitalisation for acute pulmonary embolism in the real-world clinical practice of different countries : Analysis from the RIETE registry
publishersversionPeer reviewe
The Helicobacter pylori Genome Project : insights into H. pylori population structure from analysis of a worldwide collection of complete genomes
Helicobacter pylori, a dominant member of the gastric microbiota, shares co-evolutionary history with humans. This has led to the development of genetically distinct H. pylori subpopulations associated with the geographic origin of the host and with differential gastric disease risk. Here, we provide insights into H. pylori population structure as a part of the Helicobacter pylori Genome Project (HpGP), a multi-disciplinary initiative aimed at elucidating H. pylori pathogenesis and identifying new therapeutic targets. We collected 1011 well-characterized clinical strains from 50 countries and generated high-quality genome sequences. We analysed core genome diversity and population structure of the HpGP dataset and 255 worldwide reference genomes to outline the ancestral contribution to Eurasian, African, and American populations. We found evidence of substantial contribution of population hpNorthAsia and subpopulation hspUral in Northern European H. pylori. The genomes of H. pylori isolated from northern and southern Indigenous Americans differed in that bacteria isolated in northern Indigenous communities were more similar to North Asian H. pylori while the southern had higher relatedness to hpEastAsia. Notably, we also found a highly clonal yet geographically dispersed North American subpopulation, which is negative for the cag pathogenicity island, and present in 7% of sequenced US genomes. We expect the HpGP dataset and the corresponding strains to become a major asset for H. pylori genomics
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