The impacts of cooperative learning in classrooms on student social skills

This mixed-methods action research study investigates potential effects of cooperative learning strategies on observed and self-reported student social skills in a fourth grade classroom. Baseline data is collected at a time when the classroom is predominantly whole-group and is then compared to ensuing data collected during and after cooperative learning interventions. Opportunities for students to work in interdependent partnerships and small groups ramps up gradually and culminates in a 3-week period which includes 3 different jigsaw-style lesson activities. Data suggests that students who are unaccustomed to working with peers may struggle to exhibit required social skills that make cooperative learning strategies successful, and that student experiences in social learning groups may be frustrating or stressful if the classroom has not adequately set a foundation for a social learning model. However, data also indicates that both academic performance and exhibited student social skills in cooperative groups may improve with repeated exposures. The presentation also clarifies the elements that teachers should look to include when implementing cooperative learning and provides insights into how it should be introduced

REVENUE RISK AND FISHERY CHOICE WITH LINEAR-EXPONENTIAL UTILITY: AN APPLICATION TO BERING SEA/ALEUTIAN ISLANDS TRAWL FISHERIES

A discrete choice model of 1991-96 trawl groundfish fishery participation in the Bering Sea/Aleutian Islands region is developed and estimated. The model fits well, with strong risk and seasonal effects. Notably, the model uses routinely-collected data, suggesting this type of analysis can be a regular part of the management process.Resource /Energy Economics and Policy,

TOWARD EFFICIENT BYCATCH MANAGEMENT IN MULTISPECIES FISHERIES: A NONPARAMETRIC APPROACH

Linear programming-based models of individual multispecies groundfish operations in the Bering Sea/Aleutian Islands area are developed and applied to the question of determining efficient bycatches. The policy tool is halibut quotas, which restrict the bycatch of halibut and also induce changes in the target species catch composition and bycatch of other prohibited species. Efficient quotas can be interpolated from the locus of shadow values for discrete halibut quotas relative to the opportunity cost of prohibited species bycatch induced by the policy-set quotas on halibut bycatch. Because of information limitations intrinsic to fisheries management, the efficient halibut quotas are considered in the context of ranges of marginal value and marginal opportunity cost developed using short- and long-run groundfish fishery models and standard error estimates of opportunity cost.Resource /Energy Economics and Policy,

Phenotype and animal domestication : A study of dental variation between domestic, wild, captive, hybrid and insular Sus scrofa

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Acknowledgements We thank the institutions and individuals that provided access to collections, especially the curators of the Museum für Naturkunde, Berlin; Zoologische Staatssammlung, München; Muséum National d’Histoire Naturelle, Paris; Muséum d’Histoire Naturelle, Genève; National Museum of Natural History, Washington; The Field Museum, Chicago and The American Museum of Natural History, New-York. We also thank Jean-Denis Vigne, Nelly Gidaszewski, Vincent Debat and Mathieu Joron for fruitful discussions. This work was supported by a research grant from the Natural Environment Research Council, UK (grant number NE/F003382/1).Peer reviewedPublisher PD

Using traditional biometrical data to distinguish West Palearctic wild boar and domestic pigs in the archaeological record : new methods and standards

Peer reviewedPostprin

MULTISPECIES REVENUE FUNCTION ESTIMATION FOR NORTH PACIFIC GROUNDFISH FISHERIES

Multiproduct, multispecies revenue functions are estimated for the midwater and bottom-trawl pollock fisheries off Alaska. There are strong year and seasonal effects on coefficient estimates, and the technology is joint in outputs for each major operation type. The model is a step toward prediction of fishery regulatory effects.Resource /Energy Economics and Policy,

The Polytropic Equation of State of Interstellar Gas Clouds

Models are presented for the polytropic equation of state of self-gravitating, quiescent interstellar gas clouds. A detailed analysis, including chemistry, thermal balance, and radiative transfer, is performed for the physical state of the gas as a function of density, metallicity, velocity field, and background radiation field. It is found that the stiffness of the equation of state strongly depends on all these physical parameters, and the adiabatic index varies between 0.2-1.4. The implications for star formation, in particular at high redshift and in starburst galaxies, and the initial stellar mass function are discussed.Comment: Accepted by Ap

Detecting a Stochastic Gravitational-Wave Background: The Overlap Reduction Function

Detection of a gravitational-wave stochastic background via ground or space-based gravitational-wave detectors requires the cross correlation of the response of two or more independent detectors. The cross correlation involves a frequency-dependent factor—the so-called overlap reduction function or Hellings-Downs curve—that depends on the relative geometry of each detector pair, i.e., the detector separations and the relative orientation of their antenna patterns (beams). An incorrect formulation of this geometrical factor has appeared in the literature, leading to incorrect conclusions regarding the sensitivity of proposed detectors to a stochastic gravitational-wave background. To rectify these errors and as a reference for future work we provide here a complete, first-principles derivation of the overlap reduction function and assess the nature of the errors associated with the use of the incorrect expression that has appeared in the literature. We describe the behavior of the overlap reduction function in different limiting regimes, and show how the difference between the correct and incorrect expressions can be understood physically

Serological Activity of Adsorbed Leptospiral Antigen

Leptospirosis is not a single disease but a group of diseases caused by a variety of leptospiral serotypes. Investigations during the past seventy years have shown that leptospirosis occurs in humans and animals in all areas of the world. Serological diagnostic procedures have been the principle means of identifying leptospirosis in humans and domestic animals. The agglutination test is a valuable diagnostic procedure for the identification of infections, such as leptospirosis, when it is not practical to isolate the causative organism from suspected cases. One of the earliest tests for the identification of leptospirosis was the agglutination-lysis test. This test has often been used as a basis for evaluation other leptospiral serological tests. Muraschi prepared an antigen consisting of lepostoiral components absorbed onto latex particles, for a tube agglutination test to detect leptospiral antibodies in serum. This was a modification of a procedure Singer and Flotz used for the serologic diagnosis of rheumatoid arthritis. The studies described herein pertain to tube agglutination reactions with homogenized leptospiral cell antigens absorbed onto particulate organic carriers for use as antigen in antibody-antigen reactions. The high cost of leptospiral whole cell antigen suggest the need of a search for a more economical use of this expensive material. During the course of this study, eight substances or extracts of substances were tested in solution for their suitability as fixation agents for homogenized leptospiral cell particles. From these eight substances, three appear to be suitable: supernatant of washed homogenized milk, fragments of yeast cells, and lecithin