164 research outputs found
Implementing Site-Based Management in the Rural South: The Process and the Challenge
School systems across the United States have implemented various forms of site-based management (SBM) to restructure their schools and ultimately improve education. Educators have been disappointed with the results of SBM and some have related its failure to the way SBM was implemented in many school systems. Too often, SBM was implemented as a top-down decision and viewed as a goal to obtain rather than a continuous learning process.
This study was an ethnohistorical, single-case study of a small, rural elementary school in Southeast Georgia that implemented a form of site-based management, shared governance. Data collection consisted of a combination of qualitative techniques which included interview, observation, and a review of relevant documents. A combination of the constant comparison method of analysis and the use of the QSR Nud.ist computer program was used to process and analyze the data.
This study emphasized the importance of the transformational leader and his/her ability to create conditions in schools which support change. Including teachers in the decision-making process created ownership, increased teacher satisfaction and was vital to sustaining the improvement process. Once teachers and principals collaborated together in decision making, traditional roles changed. Teachers assumed leadership roles and the principal became a facilitator instead of a dictator. The process of change was complex and took a considerable length of time before improvement occurred. Essential elements to Optima sustaining the process was support from the League of Professional Schools, the climate the principal had created at Optima, and the parental and community involvement in the school
Distribution of resprouting woody plants and the effect of fire on vegetation types in the Southern Great Plains
The effects of soil, topography, and fire on woody plant distribution and extent has been studied over numerous systems; however, most literature has focused individually on these influencing variables at single sites. In this study, we evaluated the effects of soil texture, slope, aspect, and fire measured across 39 ecological sites and four different locations in Oklahoma, USA, from 2018-2019. We used an information€ theoretic model building approach to develop models describing the effects of these predictor variables on two different estimates of woody plant cover as well as woody plant density across sites. Top models for all three woody plant metrics indicated that both woody plant cover and density were primarily influenced by percent sand, aspect direction, and the number of times burned. Metrics of woody plant cover and density declined in areas with finer soil textures, east-facing aspects, and areas that were burned more frequently across sites. Of these predictor variables, topoedaphic variables appeared overall to have a greater influence than fire. This suggests that managing woody plants with fire is partly limited by underlying soil and topographic conditions. Summary statistics at the site level mostly indicated relationships similar to cross-site analysis among woody plant metrics and predictor variables, however, there were also differences among sites. In addition to examining broad-scale patterns, we also investigated site-level relationships. Specifically, we examined the post-fire effects on woody plant vegetation type at three of the four sites. Our research suggests that these vegetation types of the Southern Great Plains recover quickly from fire and can be burned every 2-3 years to promote heterogeneity, limit the invasion of non-resprouting woody plants, and potentially benefit native wildlife. Following fire, vegetation cover and structure recovered to pre-burn conditions within 2 years post-fire at all three sites. Our research emphasizes the importance of broad-scale and site-level examination of woody plant distribution to better understand the factors influencing woody plant cover and densities to provide insightful management strategies for these landscapes
An Evaluation of a General Semantics Approach in Teaching Situational Leadership Theory in Women\u27s Volunteer Service Organizations.
This study was designed to evaluate the effects on followers\u27 perceptions of leader effectiveness and leader flexibility after training the leaders of such followers in general semantics and/or situational leadership theory. The experiment involved female volunteer leaders from three Louisiana service organizations. A 21 hour course in general semantics and situational leadership theory was taught to a research group numbering 18. A control group of 17 leaders participated in an eight hour presentation of situational leadership theory, with no reference to general semantics. Pre- and post-measurements were taken using the semantic differential and Hersey and Blanchard\u27s LEAD-Other. Leaders were rated before training and four months after training by a research group of 42 and a control group of 35 members. Data interpretation from the LEAD-Other indicated followers\u27 rating of leader effectiveness did not increase within the control group after training. Favorable ratings significantly increased in the research group, however. When measuring between the two groups, changes in leader effectiveness, once again, were not significant. The LEAD-Other, however, must be interpreted with caution. This instrument was perceived by the followers in this study as vague and cumbersome; and Hersey and Blanchard indicate no correlation between LEAD-Other effectiveness scores and actual performance. The semantic differential, on the other hand, showed consistent trends of significant changes in leader effectiveness as perceived by followers after training. This interpretation holds for analyses within the control group, within the research group, and between groups. The investigator warns, however, that strong personal feelings between volunteers may have affected members\u27 rating of one another. In addition, the researcher observed that high pre-test scores were followed by high post-test scores--which indicates little variation and could account for high significance. Flexibility also increased within the control group, within the research group, and between groups, after training. This interpretation is based on analyses of the LEAD-Other and the semantic differential. The researcher concluded that general semantics reinforces situational leadership theory. Also, volunteer organizations provide a practical lab for learning which can be transferred to business. The importance of volunteer service may be more obvious in an economy of escalating prices. Thus, future studies in training volunteers in a totally integrated course in general semantics and situation leadership theory may prove helpful--especially if a follow-up course is included to reinforce learning over time
Combination of Cardiac Progenitor Cells from the Right Atrium and Left Ventricle provide Synergistic Paracrine Effects for In Vitro Cardiac Repair
Cardiovascular diseases, such as ischaemic heart disease, remain the most common cause of death worldwide. With no effective treatment to replace the loss of cardiac tissue following a myocardial infarction, ischaemic heart disease places a significant socioeconomic burden on medicine. Advances in medical research have introduced new potential treatments, of which regenerative medicine such as stem cell therapy seem to be promising for cardiac repair. Various stem cell types have been investigated, which have different effects in cardiac repair. Combination of different cell types have been shown to improve the therapeutic potential which is thought to be due to synergistic or complimentary reparative effects.
Recently, cardiac progenitor cells (CPC) isolated from the right atrial appendage (RAA) and left ventricle have been shown to have different functional effects in vitro. Importantly, conditioned media (CM) from CPCs from the right atrial appendage (RAA CPC) have superior cardioprotective effects, while CM from the left ventricle (LV CPC) have superior angiogenic effects. Due to these distinct functional paracrine effects, this study investigated if the combination of RAA CPCs and LV CPCs from the same patient exert synergistic or complimentary paracrine effects for cardioprotection and angiogenesis in an in vitro model.
Both RAA CPCs and LV CPCs expressed the mesenchymal cell markers CD90 and CD105, and were predominantly negative for the haematopoietic cell marker, CD34. CPCs were cultured either alone or in combination and exposed to serum deprivation and hypoxic conditions (1% O2) to stimulate ischaemia. Normoxic conditions (20% O2) was used as a control. Gene expression of HIF1A, AKT1, FGF2 and PDGFA were measured to investigate the cellular responses to stimulated ischaemia. HIF1A mRNA expression was significantly decreased in the combination group of RAA CPCs and LV CPCs (RAA + LV) cultured in hypoxia and in hypoxia irrespective of groups. There were no significant differences in the expression of AKT1, FGF2 and PDGFA.
To measure the paracrine effects of CPCs, CM was collected following stimulated ischaemia. IGF-1 (pro-survival factor) and VEGF-A (pro-angiogenic factor) concentrations in CM were measured. IGF-1 concentration was comparable across all CPC groups. However, VEGF-A concentration was increased in CM collected from hypoxia, especially in the RAA and RAA + LV hypoxic CM. CM from all CPC groups reduced apoptosis in AC16 cardiomyocyte cell line exposed to stimulated ischaemia. Interestingly, RAA + LV normoxic CM was the only group that significantly increased the expression of HIF-1α protein in AC16 cardiomyocytes exposed to stimulated ischaemia. CM from all CPC groups induced angiogenesis in human umbilical vein endothelial cells and was the highest in the RAA + LV hypoxic CM.
Overall, this study provides evidence that combination of RAA CPCs and LV CPCs may have greater therapeutic effects and have synergistic paracrine effects for cardiac repair. Therefore, in vivo studies are warranted to determine if combination of different stem cell types have greater therapeutic potential than single cell therapies
Prevalence and occurrence of zoonotic bacterial pathogens in surface waters determined by quantitative PCR
The prevalence and concentrations of Campylobacter jejuni, Salmonella spp. and enterohaemorrhagic E. coli (EHEC) were investigated in surface waters in Brisbane, Australia using quantitative PCR (qPCR) based methodologies. Water samples were collected from Brisbane City Botanic Gardens (CBG) Pond, and two urban tidal creeks (i.e., Oxley Creek and Blunder Creek). Of the 32 water samples collected, 8 (25%), 1 (3%), 9 (28%), 14 (44%), and 15 (47%) were positive for C. jejuni mapA, Salmonella invA, EHEC O157 LPS, EHEC VT1, and EHEC VT2 genes, respectively. The presence/absence of the potential pathogens did not correlate with either E. coli or enterococci concentrations as determined by binary logistic regression. In conclusion, the high prevalence, and concentrations of potential zoonotic pathogens along with the concentrations of one or more fecal indicators in surface water samples indicate a poor level of microbial quality of surface water, and could represent a significant health risk to users. The results from the current study would provide valuable information to the water quality managers in terms of minimizing the risk from pathogens in surface waters
Empowering the Citizen-Consumer: Re-Regulating Consumer Information to Support the Transition to Sustainable and Health Promoting Food Systems in Canada
Both health and sustainability are stated public policy objectives in Canada, but food information rules and practices may not be optimal to support their achievement. In the absence of a stated consensus on the purposes of public information about food, the information provided is frequently determined by the marketers of product. No institution or agency has responsibility for determining the overall coherence of consumer food messages relative to these broader social goals of health and sustainability. Individual firms provide information that shows their products to best advantage, which may contradict what is provided about the product by another firm or government agency. Individual consumers do not have the resources to determine easily the completeness of any firm\u27s messages, particularly in light of the size of food industry advertising budgets. Government rules confound this problem because there is also little coherence between the parts of government that have responsibility for point of purchase, advertising rules, and labelling. The healthy eating messages of health departments are often competing with contradictory messages permitted by the regulatory framework of other arms of government. Investments in programs that successfully promote environmental stewardship in agriculture are undercut in the market because consumers cannot support those efforts with their dollars. This problem exists despite the emergence of “citizen-consumers” who have a broader approach to food purchasing than individual maximization. Only recently have some health professionals and sustainable agriculture proponents turned their attention to these factors and designed interventions that take them into account. In this paper, which builds upon earlier work by MacRae [1], we outline key short, medium and long term initiatives to facilitate the citizen-consumer phenomenon and better support consumers in their efforts to promote health and sustainability in the Canadian food system
Environmental Surveillance. An Additional/Alternative Approach for Virological Surveillance in Greece?
The detection of viruses in the sewage of an urban city by nucleic acid amplification techniques allows the identification of the viral strains that are circulating in the community. The aim of the study was the application of such detection which gives useful data on the distribution, spread, and frequency of these viruses, supporting epidemiological studies of the related viral infections. A two year (2007–2009) survey was conducted in order to evaluate the presence of human adenoviruses (hAdV), hepatitis A viruses (HAV), hepatitis E viruses (HEV), noroviruses (NoV), and human polyomaviruses (hPyV) in sewage samples collected from the inlet of a municipal biological wastewater treatment plant located in southwestern Greece. PCR methods were used for this survey. In total, viruses have been detected in 87.5% (42/48) of the analyzed sewage samples. Analytically, DNA viruses, hAdVs and hPyVs have been detected in 45.8% (22/48) and 68.8% (33/48) of the samples, respectively. As it concerns RNA viruses, HAV was detected in 8.3% (4/48), NoVs in 6.3% (3/48), while HEV has not been detected at all. After sequencing, AdVs were typed as Ad8, Ad40 and Ad41, while both JC and BK hPyVs have been recognized. All NoVs have been identified as GII4, while HAV was typed as genotype IA. Similar long-term studies could be undertaken in countries such as Greece in order to offer a valuable and complementary tool to current problematic epidemiological surveillance systems. This study demonstrates the advantages of environmental surveillance as a tool to determine the epidemiology of viruses circulating in a given community. To our knowledge this was the first of its kind study performed in Greece in order to establish this new way of surveillance
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