3,436 research outputs found
Olhando para além dos muros da escola: Uma análise do ambiente das Escolas Públicas de Minneapolis, 2004-2008
We provide an expanded environmental scan to assess the strengths, weaknesses, opportunities, and threats (SWOT) faced by education communities. Grounded in the literature, we identified 48 indicators and grouped them into 6 broad categories: (1) budget levels, (2) funding patterns, (3) community needs, (4) external economic conditions, (5) political culture, and (6) children outcomes. We then created sub-categories for each of these six groupings based on whether the data came from school reports, non-school, governmental data, or not-for-profit entities. From these data, we developed a template with strategic guidelines for education leaders in varying environmental contexts. The discussion integrates school finance, fiscal condition analysis, leadership and organizational research to develop a framework that is then applied to the Minneapolis Public Schools for school years 2004 through 2008. The retrospective examination supports the utility of the strategic guidelines offered in the framework. Education leaders found a mixed educational climate in Minneapolis Public Schools for the years examined. There was cause for concern in the declining revenues for children services by other governmental agencies and increasing numbers of schools not making annual yearly progress. However, there were also opportunities apparent in the number of schools that offered International Baccalaureate and other rigorous programs and the support of schools as indicated by passage of local referenda.Proporcionamos una exploración del entorno ampliado para evaluar las fortalezas, debilidades, oportunidades y amenazas (análisis SWOT por sus iniciales en inglés) que enfrentan las comunidades educativas. Siguiendo la literatura especializada, se identificaron 48 indicadores y agrupados en 6 grandes categorías: (1) niveles presupuestarios, (2) modalidades de financiamiento, (3) necesidades de la comunidad, (4) condiciones económicas externas, (5) cultura política, y (6) resultados de los estudiantes. Se crearon subcategorías para cada uno de estos seis grupos en función de si los datos provienen de informes escolares, datos gubernamentales no escolares, o entidades sin fines de lucro. A partir de estos datos, hemos desarrollado una plantilla con directrices estratégicas para las autoridades educativas de los diferentes contextos. La discusión integra variables de financiamiento educativo, análisis de la situación fiscal, liderazgo e investigación de la organización para desarrollar un marco conceptual que fue aplicado para analizar las escuelas públicas de Minneapolis para los años escolares 2004 hasta 2008. El examen retrospectivo apoya la utilidad de las líneas estratégicas que se ofrecen en este marco. Los líderes educativos encontraron un clima educativo mixto en escuelas públicas de Minneapolis para los años examinados. Había preocupación por la disminución de los ingresos en los servicios infantiles de otras agencias gubernamentales y el creciente número de escuelas que no consiguieron las marcas de progreso anual. Sin embargo, también hubo oportunidades de mejora evidenciadas en el número de escuelas que ofrecen Bachillerato Internacional y otros programas rigurosos y el apoyo de las escuelas, como se indica por el paso de referendos locales. Nós fornecemos uma varredura expandida para avaliar os pontos fortes, pontos fracos, oportunidades e ameaças (análise SWOT por sua sigla em Inglês) que as comunidades educativas enfrentam. Com base na literatura, foram identificados 48 indicadores que foram agrupados em seis grandes categorias: (1) os níveis de orçamento, (2) as modalidades de financiamento, (3) as necessidades da comunidade, (4) condições econômicas externas, (5) cultura política e (6) resultados dos alunos. Em seguida, forma criadas subcategorias para cada um desses seis grupos, tomando como base a proveniência dos dados: se provêm de relatórios escolares, de instituições não-escolares do governo, ou de entidades sem fins lucrativos. A partir destes dados, foi desenvolvido um modelo com orientações estratégicas para autoridades educativas em diferentes contextos. A discussão inclui variáveis de financiamento da educação, a análise da situação, liderança e organização de investigação fiscal para desenvolver um marco conceitual que foi em seguida aplicado para analisar as escolas públicas de Minneapolis nos anos letivos de 2004 até 2008. O exame retrospectivo apoia a utilidade das estratégias oferecidas neste marco conceitual. Líderes educacionais encontraram um clima educacional misto nas escolas públicas de Minneapolis nos anos analisados. Houve uma grande preocupação sobre o declínio das receitas de serviços para crianças por outras agências do governo e do número crescente de escolas que não conseguiram atingir as metas de progresso anual. No entanto, houve também oportunidades de melhoria evidenciadas no número de escolas que oferecem Bacharelado Internacional e outros programas rigorosos e apoio das escolas, conforme indicado pela passagem de referendos locais.
Endothelin-Induced Sarcoplasmic Reticulum Calcium Depletion Waves in Vascular Smooth Muscle Cells
Agonist-stimulated waves of elevated cytoplasmic Ca2+ concentration ([Ca2+]i ) regulate blood vessel tone and vasomotion in vascular smooth muscle. Previous studies employing cytoplasmic Ca2+ indicators revealed that these Ca2+ waves were generated by a combination of inositol 1,4,5-trisphosphate (IP3) and Ca2+ induced Ca2+ release (CICR) from the sarcoplasmic reticulum (SR); although, some of the mechanistic details remain uncertain. However, these findings were derived indirectly from observing agonist-induced [Ca2+]i fluctuations in the cytoplasm.
Here, for the first time, we have recorded Endothelin-1 (ET-1) induced waves of Ca2+ depletion from the SR lumen in vascular smooth muscle cells (VSMCs) using a calsequestrin-targeted Ca2+ indicator. Our findings show that these waves: (1) are due to regenerative CICR by the receptors for IP3 (IP3R), (2) have a marked latency period, (3) are characterized by a transient increase in SR Ca2+ ([Ca2+]SR ) both at the point of origin and at the wave front, (4) proceed with diminishing velocity, and (5) are arrested by the nuclear envelope. Our quantitative model indicates that the gradual decrease in the velocity of the SR depletion wave, in the absence of external Ca2+, results from continuity of the SR luminal network
Intercontinental transport of pollution manifested in the variability and seasonal trend of springtime O3 at northern middle and high latitudes
Observations (0–8 km) from the Tropospheric Ozone Production about the Spring Equinox (TOPSE) experiment are analyzed to examine air masses contributing to the observed variability of springtime O3 and its seasonal increase at 40°–85°N over North America. Factor analysis using the positive matrix factorization and principal component analysis methods is applied to the data set with 14 chemical tracers (O3, NOy, PAN, CO, CH4, C2H2, C3H8, CH3Cl, CH3Br, C2Cl4, CFC-11, HCFC-141B, Halon-1211, and 7Be) and one dynamic tracer (potential temperature). Our analysis results are biased by the measurements at 5–8 km (70% of the data) due to the availability of 7Be measurements. The identified tracer characteristics for seven factors are generally consistent with the geographical origins derived from their 10 day back trajectories. Stratospherically influenced air accounts for 14 ppbv (35–40%) of the observed O3 variability for data with O3concentrations \u3c100 ppbv at middle and high latitudes. It accounts for about 2.5 ppbv/month (40%) of the seasonal O3 trend at midlatitudes but for only 0.8 ppbv/month (\u3c20%) at high latitudes, likely reflecting more vigorous midlatitude dynamical systems in spring. At midlatitudes, reactive nitrogen-rich air masses transported through Asia are much more significant (11 ppbv in variability and 3.5 ppbv/month in trend) than other tropospheric contributors. At high latitudes the O3 variability is significantly influenced by air masses transported from lower latitudes (11 ppbv), which are poor in reactive nitrogen. The O3 trend, in contrast, is largely defined by air masses rich in reactive nitrogen transported through Asia and Europe across the Pacific or the Arctic (3 ppbv/month). The influence from the stratospheric source is more apparent at 6–8 km, while the effect of O3 production and transport within the troposphere is more apparent at lower altitudes. The overall effect of tropospheric photochemical production, through long-range transport, on the observed O3 variability and its seasonal trend is more important at high latitudes relative to more photochemically active midlatitudes
Endometriosis and the Fallopian Tubes: Theories of Origin and Clinical Implications
Endometriosis is a common, oestrogen driven chronic condition, where endometrium-like epithelial and stromal cells exist in ectopic sites. At present, no curative treatments are available and the existing evidence for disease progression is conflicting. The pathogenesis is still unknown and evidently complex, as mechanisms of initiation may depend on the anatomical distribution of endometriotic lesions. However, amongst the numerous theories and plethora of mechanisms, contributions of the fallopian tubes (FT) to endometriosis are rarely discussed. The FT are implicated in all endometriosis associated symptomatology and clinical consequences; they may contribute to the origin of endometriotic tissue, determine the sites for ectopic lesion establishment and act as conduits for the spread of proinflammatory media. Here, we examine the available evidence for the contribution of the human FT to the origin, pathogenesis and symptoms/clinical consequences of endometriosis. We also examine the broader topic linking endometriosis and the FT epithelium to the genesis of ovarian epithelial cancers. Further studies elucidating the distinct functional and phenotypical characteristics of FT mucosa may allow the development of novel treatment strategies for endometriosis that are potentially curative
Characterization Of Commercial Magnetorheological Fluids At High Shear Rate: Influence Of The Gap
This paper reports the experimental tests on the behaviour of a commercial MR fluid at high shear rates and the effect of the gap. Three gaps were considered at multiple magnetic fields and shear rates. From an extended set of almost two hundred experimental flow curves, a set of parameters for the apparent viscosity are retrieved by using the Ostwald de Waele model for non-Newtonian fluids. It is possible to simplify the parameter correlation by making the following considerations: the consistency of the model depends only on the magnetic field, the flow index depends on the fluid type and the gap shows an important effect only at null or very low magnetic fields. This lead to a simple and useful model, especially in the design phase of a MR based product. During the off state, with no applied field, it is possible to use a standard viscous model. During the active state, with high magnetic field, a strong non-Newtonian nature becomes prevalent over the viscous one even at very high shear rate; the magnetic field dominates the apparent viscosity change, while the gap does not play any relevant role on the system behaviour. This simple assumption allows the designer to dimension the gap only considering the non-active state, as in standard viscous systems, and taking into account only the magnetic effect in the active state, where the gap does not change the proposed fluid model
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Observation-based modeling of ozone chemistry in the Seoul metropolitan area during the Korea-United States Air Quality Study (KORUS-AQ)
The Seoul Metropolitan Area (SMA) has a population of 24 million and frequently experiences unhealthy levels of ozone (O3). In this work, measurements taken during the Korea-United States Air Quality Study (KORUS-AQ, 2016) are used to explore regional gradients in O3 and its chemical precursors, and an observationally-constrained 0-D photochemical box model is used to quantify key aspects of O3 production including its sensitivity to precursor gases. Box model performance was evaluated by comparing modeled concentrations of select secondary species to airborne measurements. These comparisons indicate that the steady state assumption used in 0-D box models cannot describe select intermediate species, highlighting the importance of having a broad suite of trace gases as model constraints. When fully constrained, aggregated statistics of modeled O3 production rates agreed with observed changes in O3, indicating that the box model was able to represent the majority of O3 chemistry.
Comparison of airborne observations between urban Seoul and a downwind receptor site reveal a positive gradient in O3 coinciding with a negative gradient in NOx, no gradient in CH2O, and a slight positive gradient in modeled rates of O3 production. Together, these observations indicate a radical-limited (VOC-limited) O3 production environment in the SMA. Zero-out simulations identified C7+ aromatics as the dominant VOC contributors to O3 production, with isoprene and anthropogenic alkenes making smaller but appreciable contributions. Simulations of model sensitivity to decreases in NOx produced results that were not spatially uniform, with large increases in O3 production predicted for urban Seoul and decreases in O3 production predicted for far-outlying areas. The policy implications of this work are clear: Effective O3 mitigation strategies in the SMA must focus on reducing local emissions of C7+ aromatics, while reductions in NOx emissions may increase O3 in some areas but generally decrease the regional extent of O3 exposure
Exchange rate uncertainty and international portfolio flows: A multivariate GARCH-in-mean approach
This paper examines the impact of exchange rate uncertainty on different components of net portfolio flows, namely net equity and net bond flows, as well as their dynamic linkages. Specifically, a bivariate VAR GARCH-BEKK-in-mean model is estimated using bilateral monthly data for the US vis-à-vis Australia, Canada, the euro area, Japan, Sweden, and the UK over the period 1988:01-2011:12. The results indicate that the effect of exchange rate uncertainty on net equity flows is negative in the euro area, the UK and Sweden, and positive in Australia. The impact on net bond flows is also negative in all countries except Canada, where it is positive. Under the assumption of risk aversion, the findings suggest that exchange rate uncertainty induces a home bias and causes investors to reduce their financial activities to maximise returns and minimise exposure to uncertainty, this effect being stronger in the UK, the euro area and Sweden compared to Canada, Australia and Japan. Overall, the results indicate that exchange rate or credit controls on these flows can be used as a policy tool in countries with strong uncertainty effects to pursue economic and financial stability
One-carbon genetic variants and the role of MTHFD1 1958G>A in liver and colon cancer risk according to global DNA methylation
Several polymorphic gene variants within one-carbon metabolism, an essential pathway for nucleotide synthesis and methylation reactions, are related to cancer risk. An aberrant DNA methylation is a common feature in cancer but whether the link between one-carbon metabolism variants and cancer occurs through an altered DNA methylation is yet unclear. Aims of the study were to evaluate the frequency of one-carbon metabolism gene variants in hepatocellular-carcinoma, cholangiocarcinoma and colon cancer, and their relationship to cancer risk together with global DNA methylation status. Genotyping for BHMT 716A>G, DHFR 19bp ins/del, MTHFD1 1958G>A, MTHFR 677C>T, MTR 2756A>G, MTRR 66A>G, RFC1 80G>A, SHMT1 1420C>T, TCII 776C>G and TS 2rpt-3rpt was performed in 102 cancer patients and 363 cancer-free subjects. Methylcytosine (mCyt) content was measured by LC/MS/MS in peripheral blood mononuclear cells (PBMCs) DNA. The MTHFD1 1958AA genotype was significantly less frequent among cancer patients as compared to controls (p = 0.007) and related to 63% reduction of overall cancer risk (p = 0.003) and 75% of colon cancer risk (p = 0.006). When considering PBMCs mCyt content, carriers of the MTHFD1 1958GG genotype showed a lower DNA methylation as compared to carriers of the A allele (p = 0.048). No differences were highlighted by evaluating a possible relationship between the other polymorphisms analyzed with cancer risk and DNA methylation. The MTHFD1 1958AA genotype is linked to a significantly reduced cancer risk. The 1958GG genotype is associated to PBMCs DNA hypomethylation as compared to the A allele carriership that may exert a protective effect for cancer risk by preserving from DNA hypomethylation
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