2,987 research outputs found
An investigation of the predictive effects of bullying behaviors and the psychosocial environment of schools on behaviors of middle school students
The purpose of this study was to examine the relationships among a school\u27s psychosocial environment and the prevalence and types of bullying behaviors that either lead to or resulted from that environment. More specifically, this study examined how the frequency of aggressive behaviors (e.g., bullying) experienced by students (as perpetrators and victims) contributed to their interpretation of their schools\u27 psychosocial environment and how those environments effected the existence of ongoing aggressive and avoidance behaviors. The data for this study was archival, having originally been collected for a study of school culture, climate and violence from the Philadelphia School District during the school year of 1993-1994. The current study used structural equation modeling (SEM) analysis to develop a theoretical model of predictive relationships among (a) students\u27 perceptions of bullying behaviors and safety at school, (b) the schools\u27 psychosocial environment as measured by the students and (c) the students\u27 reactionary behavior to both (a) and (b) in order to understand the consequences of bullying in schools. The sample of 5,153 student surveys was randomly split into two groups in order to examine and test a model for Group 1 and then to be able to test a cross-validation analysis with the data from Group 2. This cross-validation helped to determine if the proposed model accurately predicted the proposed relationships across different samples
Microbiological characterization of post-eruption “snowblower” vents at Axial Seamount, Juan de Fuca Ridge
© The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Frontiers in Microbiology 4 (2013): 153, doi:10.3389/fmicb.2013Microbial processes within the subseafloor can be examined during the ephemeral and uncommonly observed phenomena known as snowblower venting. Snowblowers are characterized by the large quantity of white floc that is expelled from the seafloor following mid-ocean ridge eruptions. During these eruptions, rapidly cooling lava entrains seawater and hydrothermal fluids enriched in geochemical reactants, creating a natural bioreactor that supports a subseafloor microbial “bloom.” Previous studies hypothesized that the eruption-associated floc was made by sulfide-oxidizing bacteria; however, the microbes involved were never identified. Here we present the first molecular analysis combined with microscopy of microbial communities in snowblower vents from samples collected shortly after the 2011 eruption at Axial Seamount, an active volcano on the Juan de Fuca Ridge. We obtained fluid samples and white flocculent material from active snowblower vents as well as orange flocculent material found on top of newly formed lava flows. Both flocculent types revealed diverse cell types and particulates when examined by phase contrast and scanning electron microscopy (SEM). Distinct archaeal and bacterial communities were detected in each sample type through Illumina tag sequencing of 16S rRNA genes and through sequencing of the sulfide oxidation gene, soxB. In fluids and white floc, the dominant bacteria were sulfur-oxidizing Epsilonproteobacteria and the dominant archaea were thermophilic Methanococcales. In contrast, the dominant organisms in the orange floc were Gammaproteobacteria and Thaumarchaeota Marine Group I. In all samples, bacteria greatly outnumbered archaea. The presence of anaerobic methanogens and microaerobic Epsilonproteobacteria in snowblower communities provides evidence that these blooms are seeded by subseafloor microbes, rather than from microbes in bottom seawater. These eruptive events thus provide a unique opportunity to observe subseafloor microbial communities. - See more at: http://journal.frontiersin.org/Journal/10.3389/fmicb.2013.00153/abstract#sthash.bg9RZMA7.dpufThis work was supported by a National Science Foundation Grant OCE-0929167 (to Julie A. Huber), a NASA Astrobiology Postdoctoral Fellowship (to Nancy H. Akerman), and a Center for Dark Energy Biosphere Investigations Postdoctoral Fellowship (to Julie L. Meyer)
Andragogy and community college education: An analysis of the importance of enhancing self-concept/self-esteem in the nontraditional student
The purpose of this research paper was to explore the characteristics and needs of the nontraditional, American adult students attending community colleges. The paper argues that enhancing the self-concept and self-esteem of the nontraditional, adult student fosters and increases his/her academic success and life chances. The literature review first focused on the history, description, philosophy, purpose, and mission of community colleges. In order to adequately explore issues with the nontraditional student, a review of the literature on adult development was incorporated. Then, the paper described the unique characteristics of the nontraditional, adult student, who tends to enroll in community colleges. Further, the literature reinforced the belief that enhancement of self concept, self-esteem, while incorporating principles of andragogy, would be of great value to the overall development of the nontraditional, adult student. The research paper also described a workshop aimed at the topic of educating nontraditional, adult students and emphasizing the importance of enhancing their self-concept, self-esteem. The workshop design is adaptable to a variety of audiences
Epigenetic Plasticity Drives Adipogenic and Osteogenic Differentiation of Marrow-derived Mesenchymal Stem Cells
Terminal differentiation of multipotent stem cells is achieved through a coordinated cascade of activated transcription factors and epigenetic modifications that drive gene transcription responsible for unique cell fate. Within the mesenchymal lineage, factors such as RUNX2 and PPARγ are indispensable for osteogenesis and adipogenesis, respectively. We therefore investigated genomic binding of transcription factors and accompanying epigenetic modifications that occur during osteogenic and adipogenic differentiation of mouse bone marrow-derived mesenchymal stem cells (MSCs). As assessed by ChIP-sequencing and RNA-sequencing analyses, we found that genes vital for osteogenic identity were linked to RUNX2, C/EBPβ, retinoid X receptor, and vitamin D receptor binding sites, whereas adipocyte differentiation favored PPARγ, retinoid X receptor, C/EBPα, and C/EBPβ binding sites. Epigenetic marks were clear predictors of active differentiation loci as well as enhancer activities and selective gene expression. These marrow-derived MSCs displayed an epigenetic pattern that suggested a default preference for the osteogenic pathway; however, these patterns were rapidly altered near the Adipoq, Cidec, Fabp4, Lipe, Plin1, Pparg, and Cebpa genes during adipogenic differentiation. Surprisingly, we found that these cells also exhibited an epigenetic plasticity that enabled them to trans-differentiate from adipocytes to osteoblasts (and vice versa) after commitment, as assessed by staining, gene expression, and ChIP-quantitative PCR analysis. The osteogenic default pathway may be subverted during pathological conditions, leading to skeletal fragility and increased marrow adiposity during aging, estrogen deficiency, and skeletal unloading. Taken together, our data provide an increased mechanistic understanding of the epigenetic programs necessary for multipotent differentiation of MSCs that may prove beneficial in the development of therapeutic strategies
A Population-Based Study of the Association of Medical Manpower with County Trauma Death Rates in the United States
OBJECTIVE: To determine the association between measures of medical manpower available to treat trauma patients and county trauma death rates in the United States. The primary hypothesis was that greater availability of medical manpower to treat trauma injury would be associated with lower trauma death rates. SUMMARY BACKGROUND DATA: When viewed from the standpoint of the number of productive years of life lost, trauma has a greater effect on health care and lost productivity in the United States than any disease. Allocation of health care manpower to treat injuries seems logical, but studies have not been done to determine its efficacy. The effect of medical manpower and hospital resource allocation on the outcome of injury in the United States has not been fully explored or adequately evaluated. METHODS: Data on trauma deaths in the United States were obtained from the National Center for Health Statistics. Data on the number of surgeons and emergency medicine physicians were obtained from the American Hospital Association and the American Medical Association. Data on physicians who have participated in the American College of Surgeons (ACS) Advanced Trauma Life Support Course (ATLS) were obtained from the ACS. Membership information for the American Association for Surgery of Trauma (AAST) was obtained from that organization. Demographic data were obtained from the United States Census Bureau. Multivariate stepwise linear regression and cluster analysis were used to model the county trauma death rates in the United States. The Statistical Analysis System (Cary, NC) for statistical analysis was used. RESULTS: Bivariate and multivariate analyses showed that a variety of medical manpower measures and demographic factors were associated with county trauma death rates in the United States. As in other studies, measures of low population density and high levels of poverty were found to be strongly associated with increased trauma death rates. After accounting for these variables, using multivariate analysis and cluster analysis, an increase in the following medical manpower measures were associated with decreased county trauma death rates: number of board-certified general surgeons, number of board-certified emergency medicine physicians, number of AAST members, and number of ATLS-trained physicians. CONCLUSIONS: This study confirms previous work that showed a strong relation among measures of poverty, rural setting, and increased county trauma death rates. It also found that counties with more board-certified surgeons per capita and with more surgeons with an increased interest (AAST membership) or increased training (ATLS) in trauma care have lower per-capita trauma death rates
Protein and metal cluster structure of the wheat metallothionein domain γ-Ec-1: the second part of the puzzle
Metallothioneins (MTs) are small cysteine-rich proteins coordinating various transition metal ions, including ZnII, CdII, and CuI. MTs are ubiquitously present in all phyla, indicating a successful molecular concept for metal ion binding in all organisms. The plant MT Ec-1 from Triticum aestivum, common bread wheat, is a ZnII-binding protein that comprises two domains and binds up to six metal ions. The structure of the C-terminal four metal ion binding βEdomain was recently described. Here we present the structure of the N-terminal second domain, γ-Ec-1, determined by NMR spectroscopy. The γ-Ec-1 domain enfolds an M 2 II Cys6 cluster and was characterized as part of the full-length Zn6Ec-1 protein as well as in the form of the separately expressed domain, both in the ZnII-containing isoform and the CdII-containing isoform. Extended X-ray absorption fine structure analysis of Zn2γ-Ec-1 clearly shows the presence of a ZnS4 coordination sphere with average Zn-S distances of 2.33Å. 113CdNMR experiments were used to identify the MII-Cys connectivity pattern, and revealed two putative metal cluster conformations. In addition, the general metal ion coordination abilities of γ-Ec-1 were probed with CdII binding experiments as well as by pH titrations of the ZnII and CdII forms, the latter suggesting an interaction of the γdomain and the βEdomain within the full-length protei
- …