4,111 research outputs found
Soft Tissue Edema Around Musculoskeletal Sarcomas at Magnetic Resonance Imaging
The presence of soft tissue edema around a malignant musculoskeletal neoplasm can interfere with accurate local tumor
staging at magnetic resonance imaging. This article discusses and illustrates such edema, emphasizing means for avoiding
misinterpretation of edema and subsequent overstaging
MR Imaging of Bone Marrow in Patients with Musculoskeletal Tumors
Knowledge of the appearances of normal bone marrow, metastases involving marrow,
and therapy-related marrow changes shown by MR imaging is necessary in order to avoid
misdiagnosis. This article reviews MR imaging techniques and the findings that allow
distinction of normal yellow (fatty) marrow and red marrow from tumor in marrow,
as well as the identification of marrow changes resulting from radiation therapy or
treatment with marrow-stimulating drugs in patients with musculoskeletal tumors
Assessment of Neurovascular Involvement by Malignant Musculoskeletal Tumors
Determining the presence or absence of neurovascular involvement by a malignant musculoskeletal neoplasm is an
important aspect of local tumor staging. This article discusses issues concerning such assessments made by diagnostic
imaging techniques, including factors inherent to the patient and those related to imaging technology. The distinction
between tumor contact and tumor encasement is emphasized and illustrated
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Air conditioning and source-specific particles as modifiers of the effect of PM(10) on hospital admissions for heart and lung disease.
Studies on acute effects of particulate matter (PM) air pollution show significant variability in exposure-effect relations among cities. Recent studies have shown an influence of ventilation on personal/indoor-outdoor relations and stronger associations of adverse effects with combustion-related particles. We evaluated whether differences in prevalence of air conditioning (AC) and/or the contribution of different sources to total PM(10) emissions could partly explain the observed variability in exposure-effect relations. We used regression coefficients of the relation between PM(10) and hospital admissions for chronic obstructive pulmonary disease (COPD), cardiovascular disease (CVD), and pneumonia from a recent study in 14 U.S. cities. We obtained data on the prevalence of AC from the 1993 American Housing Survey and data on PM(10) emissions by source category, vehicle miles traveled (VMT), and population density from the U.S. EPA. We analyzed data using meta-regression techniques. PM(10) regression coefficients for CVD and COPD decreased significantly with increasing percentage of homes with central AC when cities were stratified by whether their PM(10) concentrations peaked in winter or non-winter months. PM(10) coefficients for CVD increased significantly with increasing percentage of PM(10) emission from highway vehicles, highway diesels, oil combustion, metal processing, decreasing percentage of PM(10) emission from fugitive dust, and increasing population density and VMT/mile(2). In multivariate analysis, only percentage of PM(subscript)10(/subscript) from highway vehicles/diesels and oil combustion remained significant. For COPD and pneumonia, associations were less significant but the patterns of the associations were similar to that for CVD. The results suggest that air conditioning and proportion of especially traffic-related particles significantly modify the effect of PM(10) on hospital admissions, especially for CVD
Professional Development for Educational Leaders in the Era of Performance Evaluation Reform
The word “accountability” has become a mantra in public education. Arguably, this one word, and the movement it has produced, has shaped the direction of our field in the past decade more than any other (Harris, 2011). This movement has led to many positive changes including an examination of gaps in student achievement, the types of assessments used in schools, and the strength of the performance evaluation systems for principals and teachers. Many large urban school districts, as well as entire states, have revamped the way public school principals and teachers are evaluated. In fact many, including the State of Tennessee, Dallas Independent School District, Milwaukee Public Schools, Houston Independent School District, and the State of Illinois, have started or will start using some sort of student achievement metric as part of teacher and/or principal performance evaluations. The ideas surrounding using student growth seem simple enough: If student test scores improve, it means the teacher or principal is doing his or her job well and therefore should be rewarded. This seemingly simple idea is in fact quite complex. Many school administrators may not have the background or training to implement growth models as part of performance evaluations (Mitgang, 2012), which could lead to potentially unethical and incorrect implementation of newer forms of accountability such as growth modeling. Such problems have already arisen in a number of districts across the nation (Harris, 2011)
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Populations and determinants of airborne fungi in large office buildings
Bioaerosol concentrations in office environments and their roles in causing building-related symptoms have drawn much attention in recent years. Most bioaerosol studies have been cross-sectional. We conducted a longitudinal study to examine the characteristics of airborne fungal populations and correlations with other environmental parameters in office environments. We investigated four office buildings in Boston, Massachusetts, during 1 year beginning May 1997, recruiting 21 offices with open workstations. We conducted intensive bioaerosol sampling every 6 weeks resulting in 10 sets of measurement events at each workstation, and recorded relative humidity, temperature, and CO2 concentrations continuously. We used principal component analysis (PCA) to identify groups of culturable fungal taxa that covaried in air. Four major groupings (PCA factors) were derived where the fungal taxa in the same groupings shared similar ecological requirements. Total airborne fungal concentrations varied significantly by season (highest in summer, lowest in winter) and were positively correlated with relative humidity and negatively related to CO2 concentrations. The first and second PCA factors had similar correlations with environmental variables compared with total fungi. The results of this study provide essential information on the variability within airborne fungal populations in office environments over time. These data also provide background against which cross-sectional data can be compared to facilitate interpretation. More studies are needed to correlate airborne fungi and occupants' health, controlling for seasonal effects and other important environmental factors
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