Structure of AlSb(001) and GaSb(001) Surfaces Under Extreme Sb-rich Conditions

We use density-functional theory to study the structure of AlSb(001) and GaSb(001) surfaces. Based on a variety of reconstruction models, we construct surface stability diagrams for AlSb and GaSb under different growth conditions. For AlSb(001), the predictions are in excellent agreement with experimentally observed reconstructions. For GaSb(001), we show that previously proposed model accounts for the experimentally observed reconstructions under Ga-rich growth conditions, but fails to explain the experimental observations under Sb-rich conditions. We propose a new model that has a substantially lower surface energy than all (nx5)-like reconstructions proposed previously and that, in addition, leads to a simulated STM image in better agreement with experiment than existing models. However, this new model has higher surface energy than some of (4x3)-like reconstructions, models with periodicity that has not been observed. Hence we conclude that the experimentally observed (1x5) and (2x5) structures on GaSb(001) are kinetically limited rather than at the ground state.Comment: 6 pages, 6 figure

Improving Middle Grades STEM Teacher Content Knowledge and Pedagogical Practices Through a School-University Partnership

This paper outlines a University-School District partnership with the intent to increase the number of middle grades mathematics and science teachers. This externally funded initiative includes onsite, authentically situated professional development for pre- and in-service teachers at three different urban, low-socioeconomic schools with a majority Hispanic population of students. Program objectives include increasing mathematics and science content knowledge, increasing self-efficacy in teaching math and science, building and incorporating a success-driven school culture and infrastructure to increase student performance in a well-articulated, scalable and transformable model. Program components include site based common planning times, STEM Thursdays where science and mathematics lessons are practiced and refined, authentic summer research opportunities for pre- and in-service teachers to work with scientists and university faculty, teacher certification workshops and a mentoring model that includes program graduates and pre-service teachers. First year results show that the program had a positive impact on the teachers’ self-efficacy and outcome expectancy as their scores significantly increased after participation in the project. Key elements in the model included (1) a strong partnership between a school district and institution of higher education, (2) a unique collaboration between mathematics and science educators and scientists, pre-and in-service teachers, (3) a professional development and mentoring program designed around the school district’s adopted course of study and the NSES, (4) the integration of community resources, (5) a partnership with preservice and inservice teachers and district administrators with science and mathematics higher education faculty, (6) the development of teacher leaders, and (7) a comprehensive evaluation program

Impact of collaborative teaching on K-12 mathematics and science learning

A national effort is underway to transform teacher education program practices and produce effective and highly qualified teachers for 21st century classrooms. This effort prescribes providing preservice teachers (PSTs) with authentic field-based experiences that connects what is taught in teacher preparation programs with what they do in the K-12 classroom. Bridging the gap between theory and practice requires that teacher education programs collaborate with schools districts, redesigning teacher training to better serve prospective teachers and their students (NCATE, 2010). This paper describes a mixed-methods study examining the impact of a STEM site-based professional development program (TEX) on the math and science content knowledge, self-efficacy, and interest in STEM of 4-8 students as well as the self-efficacy and STEM interest in preservice and inservice teachers. The researchers found the TEX program’s collaborative model of team planning, teaching, and evaluating have led to increased student achievement and better prepared beginning teacher

Growing STEM roots: Preparing preservice teachers

This mixed-methods pilot study investigates elementary and secondary pre-service teachers’ (n=12) mathematics and science content knowledge and conceptions of nature of science following the first year implementation of a science and mathematics site-based professional development program. This study utilized pre/post data from science and mathematics content exams, and Views of Nature of Science-C instrument. Data revealed gains in preservice teachers’mathematics and science content knowledge and perceptions regarding the nature of science

Broad spectrum proteomics analysis of the inferior colliculus following acute hydrogen sulfide exposure.

Acute exposure to high concentrations of H2S causes severe brain injury and long-term neurological disorders, but the mechanisms involved are not known. To better understand the cellular and molecular mechanisms involved in acute H2S-induced neurodegeneration we used a broad-spectrum proteomic analysis approach to identify key molecules and molecular pathways involved in the pathogenesis of acute H2S-induced neurotoxicity and neurodegeneration. Mice were subjected to acute inhalation exposure of up to750 ppm of H2S. H2S induced behavioral deficits and severe lesions including hemorrhage in the inferior colliculus (IC). The IC was microdissected for proteomic analysis. Tandem mass tags (TMT) liquid chromatography mass spectrometry (LC-MS/MS)-based quantitative proteomics was applied for protein identification and quantitation. LC-MS/MS identified 598, 562, and 546 altered proteomic changes at 2 h, and on days 2 and 4 post-H2S exposure, respectively. Of these, 77 proteomic changes were statistically significant at any of the 3 time points. Mass spectrometry data were subjected to Perseus 1.5.5.3 statistical analysis, and gene ontology heat map clustering. Expressions of several key molecules were verified to confirm H2S-dependent proteomics changes. Webgestalt pathway overrepresentation enrichment analysis with Panther engine revealed H2S exposure disrupted several biological processes including metabotropic glutamate receptor group 1 and inflammation mediated by chemokine and cytokine signaling pathways among others. Further analysis showed that energy metabolism, integrity of blood-brain barrier, hypoxic, and oxidative stress signaling pathways were also implicated. Collectively, this broad-spectrum proteomics data has provided important clues to follow up in future studies to further elucidate mechanisms of H2S-induced neurotoxicity

Pharmacy-Based Travel Health Services in the United States

The aim of this paper is to review pharmacy laws and regulations, pharmacist training, clinic considerations, and patient care outcomes regarding pharmacy-based travel health services in the United States. Pharmacists and pharmacies in the United States are highly visible and accessible to the public, and have long been regarded as a source for immunization services. As international travel continues to increase and grow in popularity in this country, there is a pressing need for expanded access to preventative health services, including routine and travel vaccinations, as well as medications for prophylaxis or self-treatment of conditions that may be acquired overseas. In the United States, the scope of pharmacy practice continues to expand and incorporate these preventable health services to varying degrees on a state-by-state level. A literature review was undertaken to identify published articles on pharmacist- or pharmacy-based travel health services or care in the United States. The results of this paper show that pharmacists can help to increase access to and awareness of the need for these services to ensure that patients remain healthy while traveling abroad, and that they do not acquire a travel-related disease while on their trip. For those pharmacists interested in starting a travel health service, considerations should be made to ensure that they have the necessary training, education, and skill set in order to provide this specialty level of care, and that their practice setting is optimally designed to facilitate the service. While there is little published work available on pharmacy or pharmacist-provided travel health services in the United States, outcomes from published studies are positive, which further supports the role of the pharmacist in this setting