66 research outputs found
Assessing Acquiescence in Surveys Using Positively and Negatively Worded Questions
The purpose of this study was to assess the impact of acquiescence on both positively and negatively worded questions, both when unidimensionality was assumed and when it was not. To accomplish this, undergraduate student responses to a previously validated survey of student engagement were used to compare several models of acquiescence, using a priori goodness-offit statistics as evidence for model fit, in order to develop a model that adequately accounted for acquiescence bias. Using a true experimental design, undergraduate students from a variety of classes at a large, urban university were randomly assigned to one of three versions of the same survey of student engagement (all positively worded items, all negatively worded items, an equal balance of both positively and negatively worded items). Structural equation modeling was used to analyze the results. Although the presence of acquiescence was confirmed for both positively and negatively worded items, it was not consistent by content scale or item polarization. This suggests that there may be an interaction between item polarization and content that may cause acquiescence to be present or absent. The scales that did not show acquiescence on the balanced survey portrayed a split factor loading based upon item polarization. Further, the splitting of factor loadings by item polarization was not due to acquiescence, suggesting that something other than acquiescence is causing the loadings to split. Further research is needed to develop models and/or methods to better assess and control for acquiescence. Although demographic groups were compared by gender and race/ethnicity to assess if different groups acquiesced differently, using multi-group confirmatory factor analysis, many of the models did not converge. The findings of this study were limited by the nature of the sample size. Additional research is needed to determine if acquiescence differs by group membership
School Climate Development Survey
Over the last twenty-five years the Consortium on Chicago School Research has engaged in systematic study of more than 400 Chicago Public Schools to determine organizational traits that are related to improvement in student learning. This effort was designed to help explain widely divergent levels of student success between very similar schools in the Chicago system. Initial discussions with educators at all levels, reviews of previous research, pilot studies, and field studies led to the identification of five school contextual factors – the 5Essential Supports – determined to be critical to school success: (1) effective leaders, (2) collaborative teachers, (3) involved families, (4) supportive environment, and (5) ambitious instruction. The framework of the 5Essential Supports served as a theoretical basis for a survey effort designed to measures and report on facets of school culture that could then be used by school leaders and practitioners to guide school improvement efforts. Research related to the 5Essential Supports consistently demonstrates a strong relationship between the presence of these supports and gains in student achievement.
Led by Dr. James McMillan and Dr. Charol Shakeshaft from VCU’s School of Education, the purpose of this MERC study was (1) to develop a shortened version of the 5Essentials staff climate survey for the Metropolitan Educational Research Consortium schools, (2) to pilot test the new survey with teachers and administrators, and (3) to determine effective methods of dissemination to support schools use f the survey data for school improvement purposes. The piloting and validation phase of the study demonstrated that the core constructs underlying the 5Essentials maintained high levels of validity and reliability in the shortened version. MERC also piloted and received feedback from school leaders on formats for reporting school climate results
Response to Intervention to Educate the Diverse Needs of Elementary Students
Much research has been done regarding how to implement RTI, effective strategies for RTI, and outcomes of RTI, which is not the focus of the current study. This investigation will focus on assessing the current perceptions of elementary school educators and staff on thier current understanding of and needs for more effective implementation of RTI
Occurrence of OsHV-1 in Crassostrea gigas cultured in Ireland during an exceptionally warm summer. Selection of less susceptible oysters
The occurrence of OsHV-1, a herpes virus causing mass mortality in the Pacific oyster Crassostrea gigas was investigated with the aim to select individuals with different susceptibility to the infection. Naïve spat transferred to infected areas and juveniles currently being grown at those sites were analyzed using molecular and histology approaches. The survey period distinguishes itself by very warm temperatures reaching up to 3.5°C above the average. The virus was not detected in the virus free area although a spread of the disease could be expected due to high temperatures. Overall mortality, prevalence of infection and viral load was higher in spat confirming the higher susceptibility in early life stages. OsHV-1 and oyster mortality were detected in naïve spat after 15 days of cohabitation with infected animals. Although, infection was associated with mortality in spat, the high seawater temperatures could also be the direct cause of mortality at the warmest site. One stock of juveniles suffered an event of abnormal mortality that was significantly associated with OsHV-1 infection. Those animals were infected with a previously undescribed microvariant whereas the other stocks were infected with OsHV-1 μVar. Cell lesions due to the infection were observed by histology and true infections were corroborated by in situ hybridization. Survivors from the natural outbreak were exposed to OsHV-1 μVar by intramuscular injection and were compared to naïve animals. The survival rate in previously exposed animals was significantly higher than in naïve oysters. Results derived from this study allowed the selection of animals that might possess interesting characteristics for future analysis on OsHV-1 resistance
A large, curated, open-source stroke neuroimaging dataset to improve lesion segmentation algorithms.
Accurate lesion segmentation is critical in stroke rehabilitation research for the quantification of lesion burden and accurate image processing. Current automated lesion segmentation methods for T1-weighted (T1w) MRIs, commonly used in stroke research, lack accuracy and reliability. Manual segmentation remains the gold standard, but it is time-consuming, subjective, and requires neuroanatomical expertise. We previously released an open-source dataset of stroke T1w MRIs and manually-segmented lesion masks (ATLAS v1.2, N = 304) to encourage the development of better algorithms. However, many methods developed with ATLAS v1.2 report low accuracy, are not publicly accessible or are improperly validated, limiting their utility to the field. Here we present ATLAS v2.0 (N = 1271), a larger dataset of T1w MRIs and manually segmented lesion masks that includes training (n = 655), test (hidden masks, n = 300), and generalizability (hidden MRIs and masks, n = 316) datasets. Algorithm development using this larger sample should lead to more robust solutions; the hidden datasets allow for unbiased performance evaluation via segmentation challenges. We anticipate that ATLAS v2.0 will lead to improved algorithms, facilitating large-scale stroke research
Recommended from our members
US Renal Data System 2017 Annual Data Report: Epidemiology of Kidney Disease in the United States.
Recommended from our members
US Renal Data System 2018 Annual Data Report: Epidemiology of Kidney Disease in the United States.
Clostridium difficile infection.
Infection of the colon with the Gram-positive bacterium Clostridium difficile is potentially life threatening, especially in elderly people and in patients who have dysbiosis of the gut microbiota following antimicrobial drug exposure. C. difficile is the leading cause of health-care-associated infective diarrhoea. The life cycle of C. difficile is influenced by antimicrobial agents, the host immune system, and the host microbiota and its associated metabolites. The primary mediators of inflammation in C. difficile infection (CDI) are large clostridial toxins, toxin A (TcdA) and toxin B (TcdB), and, in some bacterial strains, the binary toxin CDT. The toxins trigger a complex cascade of host cellular responses to cause diarrhoea, inflammation and tissue necrosis - the major symptoms of CDI. The factors responsible for the epidemic of some C. difficile strains are poorly understood. Recurrent infections are common and can be debilitating. Toxin detection for diagnosis is important for accurate epidemiological study, and for optimal management and prevention strategies. Infections are commonly treated with specific antimicrobial agents, but faecal microbiota transplants have shown promise for recurrent infections. Future biotherapies for C. difficile infections are likely to involve defined combinations of key gut microbiota
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