165 research outputs found
Teachers\u27 Perceptions of Factors that Influence Teacher Turnover
Teacher turnover is a critical issue for the public education community because it influences student performance, school climate, and employee morale. In a large urban school district in the northeastern United States, the turnover rate has been high; teacher morale is low, and teacher participation in the school community is lacking. The purpose of this study was to examine the perceptions of novice teachers about factors that influence their job satisfaction and their future employment. Guided by Maslow\u27s theory of motivation-which is characterized by motivational needs that drive individuals to improved performance-this study examined the perceptions of novice teachers about job retention. The research questions focused on teachers\u27 perceptions about factors that could influence their decision to continue or leave their teaching positions. A case study design was used to capture the insights of 8 participants using semistructured interviews, reflective journals, and a focus group. Eight emergent themes were identified from the data through open coding; they involved performance affirmations, administrator and resource support, and professional development. The findings were validated through triangulation and member checking. According to the results, novice teachers sought to collaborate in a professional learning community and to expand their professional development opportunities. Hence, a project was designed to engage teachers and administrators in initiating and sustaining professional learning communities. This study may promote positive social change by increasing employee morale, staff cohesiveness, teachers\u27 effectiveness and reducing teacher attrition rates among novice teachers
Integrating Viral and Nonviral Vectors for Cystic Fibrosis Gene Therapy in the Airways
An important goal for cystic fibrosis (CF) gene therapy is to achieve long-term functional correction. While many vector options have been evaluated, integrating vectors have the greatest potential to maintain stable expression over time without a requirement for repeated administration. In this chapter, we discuss the importance of correcting the appropriate cell types, options for integrating vectors, animal models for CF gene therapy, and clinically relevant endpoint measurements. Lentiviral vectors are a promising option for CF gene therapy, as they integrate into the host genome and persistently express a transgene of interest. Airway cell tropism can be conferred by pseudotyping. Nonviral vectors such as DNA transposons can also integrate into the genome. Recent advances in hybrid viral/transposon vector technology improve the ability to deliver transposons to the airways in vivo. Integrating vector technology and new animal models have allowed considerable progress toward the goal of using gene therapy to correct life-long genetic diseases such as CF
Monocytic/Macrophagic Pneumonitis after Intrabronchial Deposition of Vascular Endothelial Growth Factor in Neonatal Lambs
Preterm and young neonates are prone to inadequate surfactant production and are susceptible to respiratory distress syndrome characterized by alveolar damage and hyaline-membrane formation. Glucocorticoid therapy is commonly used in preterm and young infants to enhance lung maturation and surfactant synthesis. Recently, vascular endothelial growth factor (VEGF) was suggested to be a novel therapeutic agent for lung maturation that lacked adverse effects in mice. The purpose of this study was to assess the safety of incremental concentration (0.0005, 0.005, and 0.05 mg/ml) and duration (16, 24, and 32 hours) of recombinant human VEGF after bronchoscopic instillation (10 ml) in neonatal lambs. High-dose VEGF caused locally extensive plum-red consolidation that was microscopically characterized by interstitial and alveolar infiltrates of cells that were morphologically and phenotypically (CD68+) consistent with monocytes/macrophages. T cells (CD3+) and B cells (CD79+) were located primarily in bronchus/bronchiole-associated lymphoid tissue and were not consistently altered by treatment with VEGF. The dose of VEGF had significant effects on both gross lesions (P \u3c .0047) and microscopic monocyte/macrophage recruitment scores (P \u3c .0001). Thus, the VEGF dose instilled into the lung greatly influenced cellular recruitment and lesion development. The post-dosing interval of VEGF in this study had minor impact (no statistical significance) on cellular recruitment. This study showed that airway deposition of VEGF in the neonatal lamb induces monocyte/macrophage recruitment to the lung and high doses can cause severe lesions. The cellular recruitment suggests further research is needed to define dosages that are efficacious in enhancing lung maturation while minimizing potential adverse effects
Ferret and Pig Models of Cystic Fibrosis: Prospects and Promise for Gene Therapy
Large animal models of genetic diseases are rapidly becoming integral to biomedical research as technologies to manipulate the mammalian genome improve. The creation of cystic fibrosis (CF) ferrets and pigs is an example of such progress in animal modeling, with the disease phenotypes in the ferret and pig models more reflective of human CF disease than mouse models. The ferret and pig CF models also provide unique opportunities to develop and assess the effectiveness of gene and cell therapies to treat affected organs. In this review, we examine the organ disease phenotypes in these new CF models and the opportunities to test gene therapies at various stages of disease progression in affected organs. We then discuss the progress in developing recombinant replication-defective adenoviral, adeno-associated viral, and lentiviral vectors to target genes to the lung and pancreas in ferrets and pigs, the two most affected organs in CF. Through this review, we hope to convey the potential of these new animal models for developing CF gene and cell therapies
Benchmarking Ontologies: Bigger or Better?
A scientific ontology is a formal representation of knowledge within a domain, typically including central concepts, their properties, and relations. With the rise of computers and high-throughput data collection, ontologies have become essential to data mining and sharing across communities in the biomedical sciences. Powerful approaches exist for testing the internal consistency of an ontology, but not for assessing the fidelity of its domain representation. We introduce a family of metrics that describe the breadth and depth with which an ontology represents its knowledge domain. We then test these metrics using (1) four of the most common medical ontologies with respect to a corpus of medical documents and (2) seven of the most popular English thesauri with respect to three corpora that sample language from medicine, news, and novels. Here we show that our approach captures the quality of ontological representation and guides efforts to narrow the breach between ontology and collective discourse within a domain. Our results also demonstrate key features of medical ontologies, English thesauri, and discourse from different domains. Medical ontologies have a small intersection, as do English thesauri. Moreover, dialects characteristic of distinct domains vary strikingly as many of the same words are used quite differently in medicine, news, and novels. As ontologies are intended to mirror the state of knowledge, our methods to tighten the fit between ontology and domain will increase their relevance for new areas of biomedical science and improve the accuracy and power of inferences computed across them
Evidence based post graduate training. A systematic review of reviews based on the WFME quality framework
<p>Abstract</p> <p>Background</p> <p>A framework for high quality in post graduate training has been defined by the World Federation of Medical Education (WFME). The objective of this paper is to perform a systematic review of reviews to find current evidence regarding aspects of quality of post graduate training and to organise the results following the 9 areas of the WFME framework.</p> <p>Methods</p> <p>The systematic literature review was conducted in 2009 in Medline Ovid, EMBASE, ERIC and RDRB databases from 1995 onward. The reviews were selected by two independent researchers and a quality appraisal was based on the SIGN tool.</p> <p>Results</p> <p>31 reviews met inclusion criteria. The majority of the reviews provided information about the training process (WFME area 2), the assessment of trainees (WFME area 3) and the trainees (WFME area 4). One review covered the area 8 'governance and administration'. No review was found in relation to the mission and outcomes, the evaluation of the training process and the continuous renewal (respectively areas 1, 7 and 9 of the WFME framework).</p> <p>Conclusions</p> <p>The majority of the reviews provided information about the training process, the assessment of trainees and the trainees. Indicators used for quality assessment purposes of post graduate training should be based on this evidence but further research is needed for some areas in particular to assess the quality of the training process.</p
The Interstellar Environment of our Galaxy
We review the current knowledge and understanding of the interstellar medium
of our galaxy. We first present each of the three basic constituents - ordinary
matter, cosmic rays, and magnetic fields - of the interstellar medium, laying
emphasis on their physical and chemical properties inferred from a broad range
of observations. We then position the different interstellar constituents, both
with respect to each other and with respect to stars, within the general
galactic ecosystem.Comment: 39 pages, 12 figures (including 3 figures in 2 parts
Legionella pneumophila induces human beta Defensin-3 in pulmonary cells
<p>Abstract</p> <p>Background</p> <p><it>Legionella pneumophila </it>is an important causative agent of severe pneumonia in humans. Human alveolar epithelium and macrophages are effective barriers for inhaled microorganisms and actively participate in the initiation of innate host defense. The beta defensin-3 (hBD-3), an antimicrobial peptide is an important component of the innate immune response of the human lung. Therefore we hypothesize that hBD-3 might be important for immune defense towards <it>L. pneumophila</it>.</p> <p>Methods</p> <p>We investigated the effects of <it>L. pneumophila </it>and different TLR agonists on pulmonary cells in regard to hBD-3 expression by ELISA. Furthermore, siRNA-mediated inhibition of TLRs as well as chemical inhibition of potential downstream signaling molecules was used for functional analysis.</p> <p>Results</p> <p><it>L. pneumophila </it>induced release of hBD-3 in pulmonary epithelium and alveolar macrophages. A similar response was observed when epithelial cells were treated with different TLR agonists. Inhibition of TLR2, TLR5, and TLR9 expression led to a decreased hBD-3 expression. Furthermore expression of hBD-3 was mediated through a JNK dependent activation of AP-1 (c-Jun) but appeared to be independent of NF-κB. Additionally, we demonstrate that hBD-3 elicited a strong antimicrobial effect on <it>L. pneumophila </it>replication.</p> <p>Conclusions</p> <p>Taken together, human pulmonary cells produce hBD-3 upon <it>L. pneumophila </it>infection via a TLR-JNK-AP-1-dependent pathway which may contribute to an efficient innate immune defense.</p
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