Complementary monostable circuits achieve low power drain and high reliability

Two-transistor multivibrator has minimum power dissipation and maximum reliability. It minimizes the use of components that are subject to environmental changes or other unpredictable behavior

Variable voltage supply uses Zener dioxide as reference

Using a zener diode as the reference element, a simple transistorized circuit provides a stable variable reference voltage

Problemas de estabilidade de desempenho dos professores não são novos: Limitações e possibilidades

Morgan, Hodge, Trepinski, and Anderson (2014) have written an article that continues to confirm what we have known for some time—teacher effects on student achievement have limited stability. In this commentary, we address the other potential contributions this work can make to inform practice, policy, and research. While illustrating Morgan et al.’s inattention to history, we take the opportunity to reframe their findings. Considering the authors’ work in the context of past and current research, we illustrate that this collective set of stable evidence should convince policymakers that it is not reasonable to assume that teachers and teaching is stable across time. Beyond this important opportunity to influence policy, we believe these findings underscore the need to build upon and expand the dependent measures we use to define and understand good teaching. After all, as we have noted (Lavigne Good, 2014; in press) good teaching involves much more than increasing students’ scores on standardized achievement tests. Morgan, Hodge, Trepinski, y Anderson (2014) han escrito un artículo que sigue confirmando lo que hemos sabido sobre la estabilidad limitada que los efectos docentes tienen en los logros de los estudiantes. En este comentario, queremos señala otras contribuciones potenciales de este trabajo que podrían informar  la práctica, política e investigación educativa. Mientras que señalamos que Morgan y colegas no prestaron suficiente atención a la historia, tenemos la oportunidad de replantear sus hallazgos. Teniendo en cuenta el trabajo de los autores en el contexto de investigaciones pasadas y actuales, proponemos que este conjunto colectivo de pruebas estable debe convencer a los políticos de que no es razonable suponer que los docentes y la enseñanza es estable a través del tiempo. Más allá de esta importante oportunidad de influir en la política, creemos que estos resultados ponen de relieve la necesidad de aprovechar y ampliar las medidas dependientes que usamos para definir y entender la buena enseñanza. Después de todo, como hemos señalado (Lavigne Good 2014; en prensa) buena enseñanza implica mucho más que el aumento de calificaciones de los estudiantes en pruebas estandarizadasMorgan, Hodge, Trepinski, e Anderson (2014) escreveram um artigo que confirma o que já sabemos sobre a estabilidade limitada dos efeitos que os professores têm sobre as avanços dos estudantes. Nese comentário, observamos outras contribuições potenciais do presente trabalho, que poderia informar a prática, política e pesquisa educacional. Enquanto notamos que Morgan e seus colegas não prestaram atenção suficiente para a história, temos a oportunidade de repensar as suas conclusões. Considerando-se o trabalho dos autores no contexto do passado e atual da pesquisa, propomos que este conjunto coletivo de provas estáveis deveria convencer os políticos de que não é razoável supor que os professores e o ensino é estável ao longo do tempo. Além deste importante oportunidade de influenciar a política, acreditamos que estes resultados destacam a necessidade de construir e expandir as medidas que usamos para definir e compreender o que é o bom ensino. Afinal, como já observamos (Lavigne Good 2014; no prelo) bom ensino envolve muito mais do que o aumento na pontuação em testes padronizado

Using Dyadic Observation to Explore Equitable Learning Opportunities in Classroom Instruction

Because of poverty, many children do not receive adequate prenatal care, nutrition, or early childhood education. These inequities combine to ensure that many students enter school with considerably less academic content knowledge and skills for learning than their peers. Teachers and schools did not create these gaps, but they must address them. The impact of schools in reducing gaps has been explored for decades only to yield inconsistent findings. One possible reason for these contradictory results is because these studies ignore classroom process. We argue for the inclusion of process in research on opportunity and achievement gaps to better articulate if schools provide inequitable learning opportunities. Further, we argue for dyadic (teacher to individual student) measurement of classroom process because commonly-used observation instruments only measure teachers’ interactions with the whole class. These instruments obscure differential teacher treatment that may exist in some classrooms. To improve policy and practice, we call for supplementing extant measures of teachers’ whole-class interactions (process) and student outcome (product) measures with those that measure dyadic interactions to learn how opportunities to learn in classrooms and schools are distributed among students to reduce, sustain, or enhance learning gaps

Improving Instructional Practice through Peer Observation and Feedback

The Every Student Succeeds Act provides an opportunity for policymakers and researchers to revisit what is known about effective teacher evaluation practices to make better-informed decisions moving forward. Principals—responsible for implementing new teacher evaluation reforms and accommodating the demands to spend more time observing and providing feedback to teachers—are overworked. They have little time to provide high-quality feedback, and may lack important content-based expertise. With these considerations in mind, we explore the role of peer observation and feedback as a vehicle to move beyond high-stakes evaluation and re-center efforts on instructional improvement. Our systematic review of extant literature (n = 38 documents, 92% peer-reviewed empirical articles) indicates that peer observation and feedback is a promising practice for instructional improvement, but one that lacks sufficient evidence. Policy, thus, can encourage innovation and research around this practice so that peer observation and feedback models can be piloted and the most effective established, as well as strategies to tackle the biggest barriers schools, particularly U.S. schools face in implementing such a practice—time

Issues of teacher performance stability are not new: Limitations and possibilities

Morgan, Hodge, Trepinski, and Anderson (2014) have written an article that continues to confirm what we have known for some time—teacher effects on student achievement have limited stability. In this commentary, we address the other potential contributions this work can make to inform practice, policy, and research. While illustrating Morgan et al.’s inattention to history, we take the opportunity to reframe their findings. Considering the authors’ work in the context of past and current research, we illustrate that this collective set of stable evidence should convince policymakers that it is not reasonable to assume that teachers and teaching is stable across time. Beyond this important opportunity to influence policy, we believe these findings underscore the need to build upon and expand the dependent measures we use to define and understand good teaching. After all, as we have noted (Lavigne & Good, 2014; in press) good teaching involves much more than increasing students’ scores on standardized achievement tests

Principal Evaluation in the United States: A National Review of State Statutes and Regulations

The growing recognition of how much principals matter for student learning and how they make a difference has fueled the need to ensure that effective principals are leading every school. One way to achieve this is through principal evaluation, which has experienced significant changes in the last decade. We conducted a national exploratory study (50 states) to document the trends in and provide an illustration of the current situation of states’ principal evaluation policies and practices. Using literature-based themes, our analysis of state statutes and regulations revealed that a majority of states have policies requiring at least one literature-based element. Only four (8%) states had statutes and/or regulations regarding allelements of principal evaluation that have been noted in the literature. Student achievement measures were the most common component—required in 66% of states. In addition, most states required principal evaluators to be trained and principals to be evaluated annually. We propose that future research focuses on the validity and reliability of measures and models used for principal evaluation—two aspects rarely addressed in principal evaluation policies—to ensure principal performance is meeting the needs of students, teachers, and schools

Histopathologic parameters as predictors of response to endoscopic sinus surgery in nonallergic patients with chronic rhinosinusitis

OBJECTIVE: To estimate the predictable value of histopathologic parameters in chronic rhinosinusitis (CRS) for response to endoscopic sinus surgery (ESS). - - - - - STUDY DESIGN: Symptomatology was rated in 100 patients prior to as well as 12 and 24 months after surgery. Specimens taken during the procedure were examined and scored for goblet cells, subepithelial thickening, mast cells, and eosinophils. Multiple regression analysis was performed to predict the total score of subjective symptoms before treatment by histopathologic parameters. The correlation between histopathologic parameters and postoperative symptoms was then evaluated. - - - - - RESULTS: Goblet cells were the best predictor correlating with 5 symptoms. Subepithelial thickening correlated with 4 symptoms. Mast cell infiltration correlated with 3 symptoms. Eosinophilic infiltration correlated with only one symptom (P<0.05). - - - - - CONCLUSION: Certain histopathologic parameters in CRS are predictive of favorable response to ESS. - - - - - SIGNIFICANCE: Pathologic evaluation may help the ENT surgeon to predict the persistence of certain CRS symptoms after ESS, even in patients at low risk for surgical failure. - - - - - EBM rating: C-4