1,216 research outputs found

    The Influence of Curiosity on Intentional and Incidental Learning

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    Previous research has indicated that the level of curiosity of an individual is related to the amount of information which that individual can acquire incidentally. The present study was conducted to test two hypotheses: (a) High curiosity children will learn more material incidentally than low curiosity children, and (b) the level of curiosity will effect intentional learning. Twenty-eight fifth grade students (14 high curious, 14 low) were selected as subjects from a pool of 77 on the basis of scores attained on the Penney and McCann (1964) Children’s Reactive Curiosity Scale. The intentional learning task was a paired-associate presentation of nine stimulus-response items using the anticipation method. The incidental cues were colored borders on the stimulus response cards of the intentional task. The intentional task was run to a criterion of two perfect recitations. When a subject reached criterion on the intentional task, he was asked to recall the incidental cues from each card. No differences were found between groups on the intentional or the incidental learning tasks. The failure to find differences is explained in terms of Postman\u27s (1964) Intrinsic-Extrinsic Stimulus Hypothesis

    Self-handicapping mediates between impulsiveness and self-discipline

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    Self-handicapping, while not a very acknowledged tendency, is very prevalent today. Especially among students of any grade level, the behavior prevents many from reaching their full potential. The purpose of this experiment was to see how Selfhandicapping mediated between Impulsiveness and Self-discipline which can later be used by teachers to help students with this phenomenon. A short survey was given to psychology undergraduate students at the University of Tennessee-Chattanooga whose age ranged from 18-44 and were predominantly Caucasian. Self-handicapping was found to mediate between Impulsiveness and Self-discipline (r = .512) compared to Impulsiveness and Self-discipline (r= .288) without using self-handicapping as a mediator. The implications that can be taken from this study include using the results in an educational setting to pinpoint selfhandicapping tendencies. Despite limitations in the study, it was conducted in an environment that was cohesive to the environment in which it would be applied

    Characteristics of Child Maltreatment and Adolescent Marijuana Use: A Prospective Study

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    There has been increasing acceptance of marijuana use in the US in recent years, and rates among adolescents have risen. At the same time, marijuana use during adolescence has been linked to an array of health and social problems. Maltreated children are at risk for marijuana use, but the relationships among characteristics of maltreatment and marijuana use are unclear. In this paper we examine how the type and the extent of maltreatment are related to the level of adolescent marijuana use. Data analyses were conducted on a subsample of maltreated adolescents (n = 702) from the Longitudinal Studies of Child Abuse and Neglect (LONGSCAN) project. Approximately half the sample had used marijuana, and maltreatment was associated with its use. Multivariate regression models showed that being male, extensive maltreatment, and peer marijuana use were associated with Heavy Use of marijuana. These findings suggest the importance of comprehensively assessing children’s maltreatment experiences and their peers’ drug use to help prevent or address possible marijuana use in these high-risk adolescents

    Use of severity classification systems in the surgical decision-making process in emergency laparotomy for perforated diverticulitis

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    Purpose: Hartman's procedure (HP) or primary anastomosis (PA) are the two surgical techniques used in patients undergoing emergency colectomy for perforated diverticulitis. There are no objective criteria to guide the surgeon's choice of procedure. This study assesses whether classification and scoring systems can be used in the decision-making process. Methods: One hundred eleven patients undergoing emergency laparotomy for perforated diverticulitis were analyzed. Logistic regression and interaction models were used to determine the predictive value in the two settings. Results: Sixty five patients underwent HP and 46 patients underwent PA. Patients with HP had significantly higher scores, median age, and were more often on immunosuppressive medication. Mortality and surgical morbidity did not differ between the groups. The clinical anastomotic leak rate was 28.3% in the PA group. In the univariate logistic regression for in-hospital death, all scores showed a significant influence. The multivariate logistic regression analysis showed that only Charlson comorbidity index (CCI) and American Society of Anesthesiologists score had a significant influence on mortality. Each score was analyzed for its predictive value regarding mortality and morbidity with respect to type of operative procedure. Only CCI revealed a trend towards statistical significance. The risk of death increases with increasing CCI when PA is performed compared to HP. Conclusion: None of the tested scores can be used to help the surgeon decide whether a PA or HP is appropriate in a specific patient. Comorbidity, represented as CCI in this study, might be more important than the locoregional situatio

    Use of LIDAR in landslide investigations: a review

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    This paper presents a short history of the appraisal of laser scanner technologies in geosciences used for imaging relief by high-resolution digital elevation models (HRDEMs) or 3D models. A general overview of light detection and ranging (LIDAR) techniques applied to landslides is given, followed by a review of different applications of LIDAR for landslide, rockfall and debris-flow. These applications are classified as: (1) Detection and characterization of mass movements; (2) Hazard assessment and susceptibility mapping; (3) Modelling; (4) Monitoring. This review emphasizes how LIDAR-derived HRDEMs can be used to investigate any type of landslides. It is clear that such HRDEMs are not yet a common tool for landslides investigations, but this technique has opened new domains of applications that still have to be develope

    Horizontal And Vertical Movements Of Juvenile Bluefin Tuna (Thunnus Thynnus), In Relation To Oceanographic Conditions Of The Western North Atlantic, Determined With Ultrasonic Telemetry

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    We employed ultrasonic transmitters to follow (for up to 48 h) the horizontal and vertical movements of five juvenile (6.8-18.7 kg estimated body mass) bluefin tuna (Thunnus thynnus) in the western North Atlantic (off the eastern shore of Virginia). Our objective was to document the fishes\u27 behavior and distribution in relation to oceanographic conditions and thus begin to address issues that currently limit population assessments based on aerial surveys. Estimation of the trends in adult and juvenile Atlantic bluefin tuna abundance by aerial surveys, and other fishery-independent measures, is considered a priority. Juvenile bluefin tuna spent the majority of their time over the continental shelf in relatively shallow water (generally less then 40 m deep). Fish used the entire water column in spite of relatively steep vertical thermal gradients (approximate to24degreesC at the surface and approximate to12degreesC at 40 m depth), but spent the majority of their time (approximate to90%) above 15 m and in water warmer then 20degreesC, Mean swimming speeds ranged from 2.8 to 3.3 knots, and total distance covered from 152 to 289 km (82-156 nmi). Because fish generally remained within relatively confined areas, net displacement was only 7.7-52.7 km (4.1-28.4 nmi). Horizontal movements were not correlated with sea surface temperature. We propose that it is unlikely that juvenile bluefin tuna in this area can detect minor horizontal temperature gradients (generally less then 0.5degreesC/km) because of the steep vertical temperature gradients (up to approximate to0.6degreesC/m) they experience during their regular vertical movements. In contrast, water clarity did appear to influence behavior because the fish remained in the intermediate water mass between the turbid and phytoplankton-rich plume exiting Chesapeake Bay (and similar coastal waters) and the clear oligotrophic water east of the continental shelf

    Benthic oxygen exchange over a heterogeneous Zostera noltei meadow in a temperate coastal ecosystem

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    Seagrass meadows support intense but highly variable benthic metabolic rates that still need to be better evaluated to determine an accurate trophic status. The present study assessed how seagrasses and associated benthic macrofauna control spatiotemporal changes in benthic oxygen exchanges within a temperate bay. Based on seasonal sampling over a complete year cycle, the diffusive oxygen uptake (DOU), community respiration (CR) and gross primary production (GPP) were measured in a Zostera noltei meadow within Arcachon Bay, taking into account its spatial heterogeneity. Oxygen fluxes were assessed in sediment cores, within which benthic macrofauna and seagrass abundances and biomasses were quantified. The presence of Z. noltei did not significantly affect the DOU. Seasonal changes in CR and GPP correlated strongly with temperature in the presence of Z. noltei. The characteristics of benthic macrofauna associated with Z. noltei only weakly affected seasonal changes in CR. High spatial changes in both GPP and CR were mainly driven by the aboveground biomass of Z. noltei. When extrapolated to the whole intertidal area of the bay, in spite of limitations, our results suggest (1) overall higher contributions to CR and GPP from the seagrass meadow than from bare sediments, even though alternative primary producers in bare sediments (likely microphytobenthos) contributed significantly during winter; (2) an annual decrease in CR and GPP of 35 and 41%, respectively, resulting from the decline in Z. noltei of 25% between 2005 and 2007; and (3) a strong seasonality in the magnitude of this decrease, which was high during autumn and low during winter.

    Directed assembly of optically bound matter

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    We present a study of optically bound matter formation in a counter-propagating evanescent field, exploiting total internal reflection on a prism surface. Small ensembles of silica microspheres are assembled in a controlled manner using optical tweezers. The structures and dynamics of the resulting optically bound chains are interpreted using a simulation implementing generalized Lorentz-Mie theory. In particular, we observe enhancement of the scattering force along the propagation direction of the optically bound colloidal chains leading to a microscopic analogue of a driven pendulum which, at least superficially, resembles Newton’s cradle

    The Fading Optical Counterpart of GRB~970228, Six Months and One Year Later

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    We report on observations of the fading optical counterpart of the gamma-ray burst GRB 970228, made with the Hubble Space Telescope STIS CCD approximately six months after outburst and with the HST/NICMOS and Keck/NIRC approximately one year after outburst. The unresolved counterpart is detected by STIS at V=28.0 +/- 0.25, consistent with a continued power-law decline with exponent -1.14 +/- 0.05. The counterpart is located within, but near the edge of, a faint extended source with diameter ~0."8 and integrated magnitude V=25.8 +/- 0.25. A reanalysis of HST and NTT observations performed shortly after the burst shows no evidence of proper motion of the point source or fading of the extended emission. Only the extended source is visible in the NICMOS images with a magnitude of H=23.3 +/- 0.1. The Keck observations find K = 22.8 +/- 0.3. Several distinct and independent means of deriving the foreground extinction in the direction of GRB 970228 all agree with A_V = 0.75 +/- 0.2. After adjusting for Galactic extinction, we find that the size of the observed extended emission is consistent with that of galaxies of comparable magnitude found in the Hubble Deep Field (HDF) and other deep HST images. Only 2% of the sky is covered by galaxies of similar or greater surface brightness; therefore the extended source is almost certainly the host galaxy. Additionally, we find that the extinction-corrected V - H and V - K colors of the host are as blue as any galaxy of comparable or brighter magnitude in the HDF. Taken in concert with recent observations of GRB 970508, GRB 971214, and GRB 980703 our work suggests that all four GRBs with spectroscopic identification or deep multicolor broad-band imaging of the host lie in rapidly star-forming galaxies.Comment: 24 pages, Latex, 4 PostScript figures, to appear in the May 10 issue of The Astrophysical Journal (Note: displayed abstract is abridged
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