Sonora semiannulata

Number of Pages: 4Integrative BiologyGeological Science

Evaluation of magnetic materials for static inverters and converters

Program studies materials for use in static inverters and converters. It gives suitable data on the behavior of commonly used materials when excited with square wave power

Investigation of aircraft landing in variable wind fields

A digital simulation study is reported of the effects of gusts and wind shear on the approach and landing of aircraft. The gusts and wind shear are primarily those associated with wind fields created by surface wind passing around bluff geometries characteristic of buildings. Also, flight through a simple model of a thunderstorm is investigated. A two-dimensional model of aircraft motion was represented by a set of nonlinear equations which accounted for both spatial and temporal variations of winds. The landings of aircraft with the characteristics of a DC-8 and a DHC-6 were digitally simulated under different wind conditions with fixed and automatic controls. The resulting deviations in touchdown points and the controls that are required to maintain the desired flight path are presented. The presence of large bluff objects, such as buildings in the flight path is shown to have considerable effect on aircraft landings

Developing a qualitative research culture in university psychology departments

We are academics in the Department of Psychology, Middlesex University. Nollaig’s research is primarily qualitative and Richard’s primarily quantitative. We form part of a team responsible for developing and delivering Research Methods modules to students at undergraduate and postgraduate level. In this paper, we draw on our experiences and those of colleagues to discuss some challenges (and possible solutions) to changing the research culture in a psychology department

Telomeric NAP1L4 and OSBPL5 of the KCNQ1 cluster, and the DECORIN gene are not imprinted in human trophoblast stem cells

Background: Genomic imprinting of the largest known cluster, the Kcnq1/KCNQ1 domain on mChr7/hChr11, displays significant differences between mouse and man. Of the fourteen transcripts in this cluster, imprinting of six is ubiquitous in mice and humans, however, imprinted expression of the other eight transcripts is only found in the mouse placenta. The human orthologues of the latter eight transcripts are biallelically expressed, at least from the first trimester onwards. However, as early development is less divergent between species, placental specific imprinting may be present in very early gestation in both mice and humans. Methodology/Principal Findings: Human embryonic stem (hES) cells can be differentiated to embryoid bodies and then to trophoblast stem (EB-TS) cells. Using EB-TS cells as a model of post-implantation invading cytotrophoblast, we analysed allelic expression of two telomeric transcripts whose imprinting is placental specific in the mouse, as well as the ncRNA KCNQ1OT1, whose imprinted expression is ubiquitous in early human and mouse development. KCNQ1OT1 expression was monoallelic in all samples but OSBPL5 and NAP1L4 expression was biallelic in EB-TS cells, as well as undifferentiated hES cells and first trimester human fetal placenta. DCN on hChr12, another gene imprinted in the mouse placenta only, was also biallelically expressed in EB-TS cells. The germline maternal methylation imprint at the KvDMR was maintained in both undifferentiated hES cells and EB-TS cells. Conclusions/Significance: The question of placental specific imprinting in the human has not been answered fully. Using a model of human trophoblast very early in gestation we show a lack of imprinting of two telomeric genes in the KCNQ1 region and of DCN, whose imprinted expression is placental specific in mice, providing further evidence to suggest that humans do not exhibit placental specific imprinting. The maintenance of both differential methylation of the KvDMR and monoallelic expression of KCNQ1OT1 indicates that the region is appropriately regulated epigenetically in vitro. Human gestational load is less than in the mouse, resulting in reduced need for maternal resource competition, and therefore maybe also a lack of placental specific imprinting. If genomic imprinting exists to control fetal acquisition of maternal resources driven by the placenta, placenta-specific imprinting may be less important in the human than the mouse

A Summary of the Effectiveness of Two Strategies for Improving Community College Mathematics Instruction: Achieving the Dream Initiatives Undertaken by the Mathematics Program at Johnson County Community College

In 2009, Johnson County Community College (JCCC) was selected to participate in the nascent Achieving the Dream (AtD) initiative. As part of that participation, the college was expected to identify significant barriers keeping their students from completing degrees and certificates. After analyzing student completion data among JCCC mathematics students, the college determined that two high-risk groups were: 1) students placing into developmental mathematics courses and; 2) students enrolled in College Algebra, the so-called gateway mathematics course at the college. In an attempt to improve success rates among those two groups of students, the mathematics division at JCCC created two initiatives—one initiative designed to improve success rates of students in developmental mathematics courses and the other initiative designed to improve success rates of students in College Algebra. This report presents an analysis of the effectiveness of: Accelerated Review Classes (ARCs) for students testing into developmental mathematics and Peer-Led Supplemental Project-Based Instruction (PSPI) sessions for students enrolled in College Algebra classes at JCCC. Data from students enrolled during the fall 2010 or spring 2011 semester were examined. The results of quantitative data analysis on persistence, success, understanding of key course concepts, and attitude toward mathematics, along with the results of qualitative data analysis on student, tutor, and instructor perceptions of the effectiveness of these initiatives are presented in this report

Periodic Instantons in SU(2) Yang-Mills-Higgs Theory

The properties of periodic instanton solutions of the classical SU(2) gauge theory with a Higgs doublet field are described analytically at low energies, and found numerically for all energies up to and beyond the sphaleron energy. Interesting new classes of bifurcating complex periodic instanton solutions to the Yang-Mills-Higgs equations are described.Comment: 11 pages, 3 figures (in 5 included eps files), ReVTeX (minor typos corrected and reference added