Gender Differences in Cooperative Learning with University Students

Differences in achievement were investigated for 80 female and 80 male university students who were randomly assigned to either cooperative or competitive teaching methods. After viewing a videotaped instruction on research design, participants completed a mini-assignment either individually in the competitive condition or with a same-sex partner in the cooperative condition. All participants individually completed a multiple-choice test to assess achievement. Although no differences were found on the multiple-choice test, on the mini-assignment women scored significantly higher in the cooperative than in the competitive condition, whereas men performed about equally in both conditions.Nous avons étudié les différences de performance chez 80 étudiants et 80 étudiantes universitaires à qui l’on avait assigné, par hasard, un projet conforme, soit à des méthodes de coopération, soit à des méthodes concurrentielles. Après avoir visionné une vidéo de directives portant sur la méthodologie de recherche, les participants ont complété un petit travail seul, dans un contexte concurrentiel, ou bien avec un partenaire de même sexe dans un contexte de coopération. De plus, tous les participants ont complété un examen à choix multiples individuellement, pour mesurer leur performance. Les résultats de cet examen ne révèlent aucune différence. Toutefois, la note e qu’ont obtenue les femmes pour le petit travail était bien plus élevée pour celui accompli dans un contexte de coopération que dans un contexte de concurrence. La performance des hommes était semblable dans les deux contextes

The relationship of certain word analysis abilities to the reading achievement of first, second, and third grade children,

Thesis (M.A.)--Boston Universit

The Use of Semipermeable Membrane Devices to Concentrate Chemicals in Oil Refinery Effluent on the Mackenzie River

To concentrate natural and refinery-derived inducers of mixed function oxygenase (MFO), semipermeable membrane devices (SPMDs) were deployed for 11-12 days in Norman Wells refinery effluent and upstream and downstream on the Mackenzie River, Northwest Territories, Canada. SPMDs, which are layflat polyethylene membrane tubes containing a thin film of purified triolein, absorb freely dissolved neutral organic chemicals that diffuse through the polyethylene membrane. Fish liver cells (Poeciliopsis lucida hepatoma; PLHC-1) were dosed with SPMD extracts; then MFO activity was determined. SPMDs from the effluent contained potent MFO inducers, equivalent to 4830-8700 pg 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD)/g SPMD. SPMDs from the site 0.5 km downstream of the refinery outfall also induced MFO, but downstream extracts were about 1/40 as potent as those from effluent-exposed SPMDs. Comparing sites on the Mackenzie River, extracts of SPMDs from downstream of the refinery outfall were over 20 times as potent as those from upstream SPMDs. Polyaromatic hydrocarbons (PAHs) and C1- to C3-substituted PAHs were abundant in extracts of SPMDs from the effluent and, to a lesser degree, in extracts of SPMDs from 0.5 km downstream. In effluent-exposed and downstream SPMDs, concentrations of parent PAHs were lower than those of C1-substituted PAHs. The highest concentrations were those of C2- and C3-substituted PAHs. It is unknown which compounds in the SPMDs caused the MFO induction, but there was a very strong correlation between the concentration of total C3-phenanthrene/anthracene in the SPMD extracts and MFO-induction potency. The study shows both the use of SPMDs as concentrators of neutral organic compounds in harsh environments (such as high temperature effluents and fast-flowing rivers) and the utility and sensitivity of the fish liver cell line for ranking MFO-inducing potencies of environmental SPMD extracts.Afin de concentrer les inducteurs naturels et dérivés de raffinerie de l'oxygénase à fonction mixte (OFM), on a déployé de l'équipement à membrane semi-perméable pendant une durée de 11 à 12 jours dans les effluents de l'usine de raffinage de Norman Wells, de même qu'en amont et en aval dans les eaux du Mackenzie (Territoires du Nord-Ouest, Canada). Ces systèmes, formés de tubes de membrane en polyéthylène aplatis contenant une mince pellicule de trioléine purifiée, absorbent abondamment les produits chimiques organiques neutres en solution qui se diffusent dans toute la membrane de polyéthylène. On a mis des extraits de cette membrane en contact avec des cellules de foie de poisson (hépatocarcinome de Poeciliopsis lucida; HCPL-1), puis on a déterminé l'activité de l'OFM. Les membranes provenant des effluents contenaient de puissants inducteurs d'OFM, équivalents à 4830-8700 pg de tétrachlorodibenzodioxine-p 2,3,7,8 (TCDD)/g de membrane. Les membranes provenant du lieu situé à 0,5 km en aval du déversoir étaient aussi des inducteurs d'OFM, mais environ quarante fois moins puissants que ceux provenant des membranes exposées directement aux effluents. En comparant les sites sur le Mackenzie, les extraits des membranes situées en aval du déversoir de la raffinerie étaient environ 20 fois plus puissants que ceux des membranes situées en amont. Les hydrocarbures aromatiques polycycliques (HAP) et les HAP de remplacement de formule C1 à C3 se trouvaient en abondance dans les extraits de membrane provenant des effluents et, à un degré moindre, dans les extraits de membrane provenant du lieu situé à 0,5 km en aval. Dans les membranes exposées aux effluents et aux eaux situées en aval, les concentrations des HAP mères étaient inférieures à celles des HAP de remplacement de formule C1. Les concentrations les plus fortes étaient celles des HAP de remplacement de formule C2 et C3. On ne sait pas quels composés présents dans les membranes ont causé l'induction de l'OFM, mais il existait une très forte corrélation entre la concentration totale de phénanthrène/anthracène dans les extraits de membrane et la puissance d'induction de l'OFM. L'étude démontre à la fois l'utilisation des membranes comme concentrateurs des composés organiques neutres dans un environnement difficile (tel celui d'effluents à haute température et de cours d'eau rapides) ainsi que l'utilité et la sensibilité de la lignée cellulaire de foie de poisson pour classer les extraits de membrane environnementale selon leur puissance d'induction de l'OFM

Ecohydrodynamics of Cold-Water Coral Reefs:A Case Study of the Mingulay Reef Complex (Western Scotland)

Ecohydrodynamics investigates the hydrodynamic constraints on ecosystems across different temporal and spatial scales. Ecohydrodynamics play a pivotal role in the structure and functioning of marine ecosystems, however the lack of integrated complex flow models for deep-water ecosystems beyond the coastal zone prevents further synthesis in these settings. We present a hydrodynamic model for one of Earth's most biologically diverse deep-water ecosystems, cold-water coral reefs. The Mingulay Reef Complex (western Scotland) is an inshore seascape of cold-water coral reefs formed by the scleractinian coral Lophelia pertusa. We applied single-image edge detection and composite front maps using satellite remote sensing, to detect oceanographic fronts and peaks of chlorophyll a values that likely affect food supply to corals and other suspension-feeding fauna. We also present a high resolution 3D ocean model to incorporate salient aspects of the regional and local oceanography. Model validation using in situ current speed, direction and sea elevation data confirmed the model's realistic representation of spatial and temporal aspects of circulation at the reef complex including a tidally driven current regime, eddies, and downwelling phenomena. This novel combination of 3D hydrodynamic modelling and remote sensing in deep-water ecosystems improves our understanding of the temporal and spatial scales of ecological processes occurring in marine systems. The modelled information has been integrated into a 3D GIS, providing a user interface for visualization and interrogation of results that allows wider ecological application of the model and that can provide valuable input for marine biodiversity and conservation applications

Parental Attitudes toward Genetic Testing for Pediatric Deafness

Recent molecular genetic advances have resulted in genetic testing becoming an option for deaf individuals and their families. However, there is little information about the interest in such testing. To investigate this issue, parents with normal hearing who have one or more deaf children were surveyed about their attitudes toward diagnostic, carrier, and prenatal genetic testing for deafness. This population was chosen because it represents the majority of individuals who are encountered in clinical practice, given that 90%–95% of deaf individuals are born to persons with normal hearing. Of 328 surveys distributed, 96 were completed and returned. Of the respondents, 96% recorded a positive attitude toward genetic testing for deafness, including prenatal testing, although none would use this information to terminate an affected pregnancy. All respondents had a poor understanding of genetics, with 98% both incorrectly estimating the recurrence risk of deafness and misunderstanding the concept of inheritance. Notably, these findings were similar in the group who had had genetic testing for their children and in the group who had not, suggesting either that the parents who received genetic testing did not receive genetic counseling or that the counseling was not effective. On the basis of these results, it was concluded that this population is interested in the use of genetic testing and that testing should not be done without first providing formal genetic counseling. Appropriate counseling can help parents to understand the risks, benefits, and limitations of genetic testing

Models based on the Mitscherlich equation for describing typical and atypical gas production profiles obtained from in vitro digestibility studies using equine faecal inoculum

Two models are proposed to describe atypical biphasic gas production profiles obtained from in vitro digestibility studies. The models are extensions of the standard Mitscherlich equation, comprising either two Mitscherlich terms or one Mitscherlich and one linear term. Two models that describe typical monophasic gas production curves, the standard Mitscherlich and the France model [a generalised Mitscherlich (root-t) equation], were assessed for comparison. Models were fitted to 25 gas production profiles resulting from incubating feedstuffs with faecal inocula from equines. Seventeen profiles displayed atypical biphasic patterns while the other eight displayed typical monophasic patterns. Models were evaluated using statistical measures of goodness-of-fit and by analysis of residuals. Good agreement was found between observed atypical profiles values and fitted values obtained with the two biphasic models, and both can revert to a simple Mitscherlich allowing them to describe typical monophasic profiles. The models contain kinetic fermentation parameters that can be used in conjunction with substrate degradability information and digesta passage rate to calculate extent of substrate degradation in the rumen or hindgut. Thus, models link the in vitro gas production technique to nutrient supply in the animal by providing information relating to digestion and nutritive value of feedstuffs

Coral cities of the deep. Species–habitat associations on the Mingulay Reef Complex

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An illustrative analysis of atypical gas production profiles obtained from in vitro digestibility studies using fecal inoculum

14 páginas, 2 tablas, 6 figuras.Gas production profiles typically show a monotonically increasing monophasic pattern. However, atypical gas production profiles exist whereby at least two consecutive phases of gas production or additional extraneous features that distort the typical profile are present. Such profiles are more likely to occur with the use of a fecal inoculum and are much less well described. The presence of multiple phases or non-descript extraneous features makes it difficult to apply directly recommended modeling approaches such as standard response functions or classical growth functions. To overcome such difficulties, extensions of the Mitscherlich equation and a numerical modeling option also based on the Mitscherlich are explored. The numerical modeling option uses an estimate of relative rate obtained from the smoothed data profile and an estimate of maximum gas produced together with any lag time information drawn from the raw data to construct a simple Mitscherlich equation. In summary, this article illustrates the analysis of atypical gas production profiles obtained using a fecal inoculum and explores the methodology of numerical modeling to reconstruct equivalent typical growth-like trends.This research was funded in part by The Canada Research Chairs program, grant number 045867 (Natural Sciences and Engineering Research Council of Canada, Ottawa)

Enhanced Aromatic Sequons Increase Oligosaccharyltransferase Glycosylation Efficiency and Glycan Homogeneity

SummaryN-Glycosylation plays an important role in protein folding and function. Previous studies demonstrate that a phenylalanine residue introduced at the n-2 position relative to an Asn-Xxx-Thr/Ser N-glycosylation sequon increases the glycan occupancy of the sequon in insect cells. Here, we show that any aromatic residue at n-2 increases glycan occupancy in human cells and that this effect is dependent upon oligosaccharyltransferase substrate preferences rather than differences in other cellular processing events such as degradation or trafficking. Moreover, aromatic residues at n-2 alter glycan processing in the Golgi, producing proteins with less complex N-glycan structures. These results demonstrate that manipulating the sequence space surrounding N-glycosylation sequons is useful both for controlling glycosylation efficiency, thus enhancing glycan occupancy, and for influencing the N-glycan structures produced