895 research outputs found

    First generation preservice teachers’ self-efficacy regarding the teaching of diverse students and the incorporation of diverse topics into classroom content

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    The purpose for this study was to examine whether there is a difference in self-efficacy between first generation and non-first generation preservice teachers to address the teaching of diverse PK-12 students. Bandura’s (1997) concept of self-efficacy was employed as a framework to understand the results of the study. A cross-sectional design was used to analyze a self-efficacy survey that was administered to first generation and non-first generation preservice teachers. A total of 55 preservice teachers nearing completion of their teacher preparation at one university participated. The data demonstrates statistically significant differences of unequal self-efficacy development between first generation and non-first generation preservice teachers despite being trained in the same program. The findings may shed light on how educator preparation programs can better prepare first generation preservice teachers to serve diverse students and the incorporation of diverse topics into classroom content

    Communications of the Lunar and Planetary Laboratory, volume 8, part 3

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    Infrared photography, mapping, and orbit calculation of natural satellites, comets, and planets in solar syste

    Working Toward Social Justice: Center for Research on Minority Health Summer Workshop on Health Disparities

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    Health disparities research encompasses a complex web of areas of cross-disciplinary expertise from fields such as health policy, public health, economics, sociology, psychology, anthropology, communications, genetics, biology, environmental science, ethics, and law. Dissemination of health disparities research is paramount to educating and training professionals, academics, community leaders, students and others about the subject area, and providing them with the necessary tools to affect change and eliminate health disparities. This paper chronicles the development of a unique health disparities and social justice research educational program held annually by The University of Texas M. D. Anderson Cancer Center, Center for Research on Minority Health. The program is composed of a college semester course and summer workshop, which in the past five years, has become a preeminent program in the United States. The program's impetus, premise, evaluation, and future directions are discussed

    Elastic waves push organic fluids from reservoir rock

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    Elastic waves have been observed to increase productivity of oil wells, although the reason for the vibratory mobilization of the residual organic fluids has remained unclear. Residual oil is entrapped as ganglia in pore constrictions because of resisting capillary forces. An external pressure gradient exceeding an ‘‘unplugging’’ threshold is needed to carry the ganglia through. The vibrations help overcome this resistance by adding an oscillatory inertial forcing to the external gradient; when the vibratory forcing acts along the gradient and the threshold is exceeded, instant ‘‘unplugging’’ occurs. The mobilization effect is proportional to the amplitude and inversely proportional to the frequency of vibrations. We observe this dependence in a laboratory experiment, in which residual saturation is created in a glass micromodel, and mobilization of the dyed organic ganglia is monitored using digital photography.We also directly demonstrate the release of an entrapped ganglion by vibrations in a computational fluid-dynamics simulation

    Denying humanness to victims: How gang members justify violent behavior

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    The high prevalence of violent offending amongst gang-involved youth has been established in the literature. Yet the underlying psychological mechanisms that enable youth to engage in such acts of violence remain unclear. 189 young people were recruited from areas in London, UK, known for their gang activity. We found that gang members, in comparison to non-gang youth, described the groups they belong to as having recognized leaders, specific rules and codes, initiation rituals, and special clothing. Gang members were also more likely than non-gang youth to engage in violent behavior and endorse moral disengagement strategies (i.e., moral justification, euphemistic language, advantageous comparison, displacement of responsibility, attribution of blame, and dehumanization). Finally, we found that dehumanizing victims partially mediated the relationship between gang membership and violent behavior. These findings highlight the effects of groups at the individual level and an underlying psychological mechanism that explains, in part, how gang members engage in violence

    Coagulation and fragmentation processes with evolving size and shape profiles : a semigroup approach

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    We investigate a class of bivariate coagulation-fragmentation equations. These equations describe the evolution of a system of particles that are characterised not only by a discrete size variable but also by a shape variable which can be either discrete or continuous. Existence and uniqueness of strong solutions to the associated abstract Cauchy problems are established by using the theory of substochastic semigroups of operators

    Nonequilibrium Phase Transitions in Models of Aggregation, Adsorption, and Dissociation

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    We study nonequilibrium phase transitions in a mass-aggregation model which allows for diffusion, aggregation on contact, dissociation, adsorption and desorption of unit masses. We analyse two limits explicitly. In the first case mass is locally conserved whereas in the second case local conservation is violated. In both cases the system undergoes a dynamical phase transition in all dimensions. In the first case, the steady state mass distribution decays exponentially for large mass in one phase, and develops an infinite aggregate in addition to a power-law mass decay in the other phase. In the second case, the transition is similar except that the infinite aggregate is missing.Comment: Major revision of tex

    Borderline Aggregation Kinetics in ``Dry'' and ``Wet'' Environments

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    We investigate the kinetics of constant-kernel aggregation which is augmented by either: (a) evaporation of monomers from finite-mass clusters, or (b) continuous cluster growth -- \ie, condensation. The rate equations for these two processes are analyzed using both exact and asymptotic methods. In aggregation-evaporation, if the evaporation is mass conserving, \ie, the monomers which evaporate remain in the system and continue to be reactive, the competition between evaporation and aggregation leads to several asymptotic outcomes. For weak evaporation, the kinetics is similar to that of aggregation with no evaporation, while equilibrium is quickly reached in the opposite case. At a critical evaporation rate, the cluster mass distribution decays as k5/2k^{-5/2}, where kk is the mass, while the typical cluster mass grows with time as t2/3t^{2/3}. In aggregation-condensation, we consider the process with a growth rate for clusters of mass kk, LkL_k, which is: (i) independent of kk, (ii) proportional to kk, and (iii) proportional to kμk^\mu, with 0<μ<10<\mu<1. In the first case, the mass distribution attains a conventional scaling form, but with the typical cluster mass growing as tlntt\ln t. When LkkL_k\propto k, the typical mass grows exponentially in time, while the mass distribution again scales. In the intermediate case of LkkμL_k\propto k^\mu, scaling generally applies, with the typical mass growing as t1/(1μ)t^{1/(1-\mu)}. We also give an exact solution for the linear growth model, LkkL_k\propto k, in one dimension.Comment: plain TeX, 17 pages, no figures, macro file prepende

    Presence of Putative Repeat-in-Toxin Gene tosA in Escherichia coli Predicts Successful Colonization of the Urinary Tract

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    Uropathogenic Escherichia coli (UPEC) strains, which cause the majority of uncomplicated urinary tract infections (UTIs), carry a unique assortment of virulence or fitness genes. However, no single defining set of virulence or fitness genes has been found in all strains of UPEC, making the differentiation between UPEC and fecal commensal strains of E. coli difficult without the use of animal models of infection or phylogenetic grouping. In the present study, we consider three broad categories of virulence factors simultaneously to better define a combination of virulence factors that predicts success in the urinary tract. A total of 314 strains of E. coli, representing isolates from fecal samples, asymptomatic bacteriuria, complicated UTIs, and uncomplicated bladder and kidney infections, were assessed by multiplex PCR for the presence of 15 virulence or fitness genes encoding adhesins, toxins, and iron acquisition systems. The results confirm previous reports of gene prevalence among isolates from different clinical settings and identify several new patterns of gene associations. One gene, tosA, a putative repeat-in-toxin (RTX) homolog, is present in 11% of fecal strains but 25% of urinary isolates. Whereas tosA-positive strains carry an unusually high number (11.2) of the 15 virulence or fitness genes, tosA-negative strains have an average of only 5.4 virulence or fitness genes. The presence of tosA was predictive of successful colonization of a murine model of infection, even among fecal isolates, and can be used as a marker of pathogenic strains of UPEC within a distinct subset of the B2 lineage
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