6,800 research outputs found
Avaliar a validade da avaliação das carteiras de acreditação
This study examines one part of a validity argument for portfolio assessments of teaching practice used as an indicator of teaching quality to inform a licensure decision. We investigate the relationship among portfolio assessment scores, a test of teacher knowledge (ETS’s Praxis I and II), and changes in student achievement (on Touchstone’s Degrees of Reading Power Test [DRP]). Key questions are the extent to which the assessment of teaching practice (a) predict gains in students’ achievement and (b) contribute unique information to this prediction beyond what is contributed by the tests of teacher knowledge. The venue for our study is Connecticut State Department of Education’s (CSDE) support and licensure system for beginning teachers, the Beginning Educator Support and Training (BEST) program (as it was implemented at the time of our study). We investigated whether elementary teachers’ mean effects on their students’ reading achievement support the use of BEST elementary literacy portfolio scores as a measure of teaching quality for licensure, using a data set gathered from both State and two urban school district sources. The HLM findings indicate that BEST portfolio scores do indeed distinguish among teachers who were more and less successful in enhancing their students’ achievement. An additional analysis indicated that the BEST portfolios add information that is not contained in the Praxis tests, and are more powerful predictors of teachers’ contributions to student achievement gains.Este estudio examina una parte de un argumento de validez para las evaluaciones de los cartera de la práctica docente utilizados como un indicador de la calidad docente para informar una decisión licencia. Investigamos la relación entre los resultados de la evaluación de cartera , una prueba de conocimientos del profesorado ( Praxis I del ETS y II), y los cambios en los logros del estudiante ( en grados de piedra de toque de la prueba eléctrica de la lectura [ DRP ] ) . Las cuestiones clave son la medida en que la evaluación de la práctica docente ( a) predecir las ganancias en el rendimiento de los estudiantes y ( b ) contribuir información única a esta predicción más allá de lo aportado por las pruebas de conocimiento de los maestros . El lugar elegido para nuestro estudio es el Departamento de apoyo y otorgamiento de licencias ( CSDE ) Sistema de Educación para los maestros principiantes del Estado de Connecticut , el Principio Educador , y la programa (BEST ) (como se implementó en el momento de nuestro estudio ) Adiestramiento. Hemos investigado si los "efectos medias en sus alumnos los profesores elementales logros en lectura apoyan el uso de las mejores puntuaciones de la cartera de alfabetización primaria como una medida de calidad de la enseñanza para obtener la licencia , el uso de un conjunto de datos recogidos de Estado y de dos fuentes distrito escolar urbano . Los hallazgos indican que las puntuaciones HLM mejor cartera de hecho distinguen entre los profesores que se encontraban cada vez menos éxito en la mejora de los logros de sus alumnos. Un análisis adicional indicó que los mejores carteras añadir información que no está contenida en las pruebas Praxis , y son más potentes predictores de las contribuciones de los profesores a las ganancias de rendimiento de los estudiantes .O presente estudo analisa uma parte de um argumento de validade para avaliação da carteira de prática de ensino utilizadas como um indicador da qualidade do ensino para informar a decisão de licença. Nós investigamos a relação entre os resultados do portfólio de avaliação, um teste de conhecimentos e competências ( ETS Praxis I e II) , e as mudanças no desempenho do aluno (em graus pedra de toque de teste elétrico leitura [ DRP ] ) . As questões-chave são a medida em que a avaliação da prática docente ( a) prever ganhos no desempenho dos alunos e ( b) contribuir com informações exclusivas para a predição além da evidência fornecida pelo conhecimento dos professores. O local escolhido para o nosso estudo é o suporte Departamento e licenciamento ( CSDE ) Sistema de Educação para professores iniciantes do Estado de Connecticut, o Educador Começando , eo programa (BEST ) (como implementado no momento do nosso estudo ) Treinamento. Nós investigamos se os "efeitos médios em seus professores elementares de leitura os alunos realização apoiar o uso das melhores pontuações da carteira de alfabetização primária como uma medida da qualidade da educação para o licenciamento , o uso de um conjunto de dados coletados fontes do Estado e dois distrito escolar urbano . os resultados indicam que as pontuações melhor portfolio HLM realmente distinguir entre os professores que estavam menos bem sucedido de sempre na melhoria da realização dos seus alunos. Uma análise indicou ainda que os melhores portfolios adicionar informações não contidas nos testes Praxis , e são preditores mais poderosos de contribuições dos professores para os ganhos de desempenho dos alunos
An Investigation of LSF-YSZ Conductive Scaffolds for Infiltrated SOFC Cathodes
Porous compostites of Sr-doped LaFeO3 (LSF and yttria-stabilized zirconia (YSZ) were investigated as conductive scaffolds for infiltrated SOFC cathodes with the goal of producing scaffolds for which only a few perovskite infiltration steps are required to achieve sufficient conductivity. While no new phases form when LSF-YSZ composites are calcined to 1623 K, shifts in the lattice parameters indicate Zr can enter the perovskite phase. Measurements on dense, LSF-YSZ composites show that the level of Zr doping depends on the Sr:La ration. Because conductivity of undoped LSF increases with Sr content while both the iconic and electronic conductivities of Zr-doped LSF decrease with the level of Zr in the perovskite phase, there is an optimum initial Sr content corresponding to La0.9Sr0.1FeO3 (LSF91). Although schaffolds made with 100% LSF had a higher conductivity then scaffolds made with 50:50 LSF-YSZ mixtures, the 50:50 mixture provides the optimal interfacial structure with the electrolyte and sufficient conductivity, providing the best cathode performance upon infiltration of La0.6Sr0.4Co0.2Fe0.8O3 (LSCF)
Pancreatic cysts suspected to be branch duct intraductal papillary mucinous neoplasm without concerning features have low risk for development of pancreatic cancer.
BackgroundThe risk of developing pancreatic cancer is uncertain in patients with clinically suspected branch duct intraductal papillary mucinous neoplasm (BD-IPMN) based on the "high-risk stigmata" or "worrisome features" criteria proposed in the 2012 international consensus guidelines ("Fukuoka criteria").MethodsRetrospective case series involving patients referred for endoscopic ultrasound (EUS) of indeterminate pancreatic cysts with clinical and EUS features consistent with BD-IPMN. Rates of pancreatic cancer occurring at any location in the pancreas were compared between groups of patients with one or more Fukuoka criteria ("Highest-Risk Group", HRG) and those without these criteria ("Lowest-Risk Group", LRG).ResultsAfter exclusions, 661 patients comprised the final cohort (250 HRG and 411 LRG patients), 62% female with an average age of 67 years and 4 years of follow up. Pancreatic cancer, primarily adenocarcinoma, occurred in 60 patients (59 HRG, 1 LRG). Prevalent cancers diagnosed during EUS, immediate surgery, or first year of follow up were found in 48/661 (7.3%) of cohort and exclusively in HRG (33/77, 42.3%). Using Kaplan-Meier method, the cumulative incidence of cancer at 7 years was 28% in HRG and 1.2% in LRG patients (P<0.001).ConclusionsThis study supports using Fukuoka criteria to stratify the immediate and long-term risks of pancreatic cancer in presumptive BD-IPMN. The risk of pancreatic cancer was highest during the first year and occurred exclusively in those with "high-risk stigmata" or "worrisome features" criteria. After the first year all BD-IPMN continued to have a low but persistent cancer risk
Do Jet-Driven Shocks ionize the Narrow Line Regions of Seyfert Galaxies?
We consider a model in which the narrow line regions (NLRs) of Seyfert
galaxies are photoionized ``in situ'' by fast (300 -- 1,000 km/s), radiative
shock waves driven into the interstellar medium of the galaxy by radio jets
from the active nucleus. Such shocks are powerful sources of soft X-rays. We
compute the expected ratio of the count rates in the ROSAT PSPC and Einstein
IPC detectors to the [OIII] \lambda 5007 flux as a function of shock velocity,
and compare these ratios with observations of type 2 Seyferts. If most of the
observed soft X-ray emission from these galaxies originates in the NLR and the
absorbing hydrogen column is similar to that inferred from the reddening of the
NLR, a photoionizing shock model with shock velocity 400 -- 500 km/s
is compatible with the observed ratios. High angular resolution observations
with AXAF are needed to isolate the X-ray emission of the NLR and measure its
absorbing column, thus providing a more conclusive test. We also calculate the
expected coronal iron line emission from the shocks. For most Seyfert 2s, the
[Fe X] \lambda 6374/H \beta$ ratio is a factor of 2 -- 14 lower than the
predictions of 300 -- 500 km/s shock models, suggesting that less hot gas is
present than required by these models.Comment: Astrophys J. Letters 1999 March 10 issue, Vol. 51
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The Observations Of The X-Ray Source Hz Herculis-Hercules X-1
NASAESASRCAstronom
Controlling laser spectra in a phaseonium photonic crystal using maser
We study the control of quantum resonances in photonic crystals with
electromagnetically induced transparency driven by microwave field. In addition
to the control laser, the intensity and phase of the maser can alter the
transmission and reflection spectra in interesting ways, producing hyperfine
resonances through the combined effects of multiple scattering in the
superstructure.Comment: 7 pages, 4 figure
Dropouts of Fully Stripped Ions in the Solar Wind: A Diagnostic for Wave Heating versus Reconnection
The SWICS instrument aboard the ACE satellite has detected frequent intervals
in the slow solar wind and interplanetary coronal mass ejections (ICMEs) in
which C6+ and other fully stripped ions are strongly depleted, though the
ionization states of elements such as Si and Fe indicate that those ions should
be present. It has been suggested that these outlier or dropout events can be
explained by the resonant cyclotron heating process, because these ions all
have the same cyclotron frequency as He2+. We investigate the region in the
corona where these outlier events form. It must be above the ionization
freeze-in height and the transition to collisionless plasma conditions, but low
enough that the wind still feels the effects of solar gravity. We suggest that
the dropout events correspond to relatively dense blobs of gas in which the
heating is reduced because local variations in the Alfven speed change the
reflection of Alfven waves and the turbulent cascade. As a result, the wave
power at the cyclotron frequency of the fully stripped ions is absorbed by He2+
and may not be able to heat the other fully-stripped ions enough to overcome
solar gravity. If this picture is borne out, it may help to discriminate
between resonant cyclotron heating and stochastic heating models of the solar
wind
Stephan's Quintet: The X-ray Anatomy of a Multiple Galaxy Collision
Chandra observations of the compact galaxy group known as Stephan's Quintet
(SQ) are presented. The major morphological features that were discovered with
the ROSAT HRI are now imaged with higher resolution and S/N. The large scale
shock (1.5', ~40kpc if at 85 Mpc) is resolved into a narrow NS feature embedded
in more extended diffuse emission (D>=3'). The NS structure is somewhat clumpy,
more sharply bounded on the W side and prominent only in the soft band
(energies below ~2 keV). Its observational properties are best explained as a
shock produced by a high velocity encounter between NGC7318b, a ``new
intruder'', and the intergalactic medium in SQ. The shock conditions near the
high speed intruder suggest that a bow shock is propagating into a pre-existing
HI cloud and heating the gas to a temperature of ~0.5 keV. The low temperature
in the shock is a problem unless we postulate an oblique shock. One member,
NGC7319, hosts a Seyfert 2 nucleus, with an intrinsic luminosity Lx=10^43
erg/s, embedded in a region of more diffuse emission with 10'' radius extent.
The nuclear spectrum can be modeled with a strongly absorbed power-law typical
of this class of sources. Several additional compact sources are detected
including three in foreground NGC7320. Some of these sources are very luminous
and could be related to the ultraluminous X-ray sources found in nearby
galaxies.Comment: Accepted for publication in Astronomy & Astrophysics Quality of
figures has been degraded to fit in the astroph requirements; fig12 could not
be inserted in the tex and is given as a jpe
Transcriptional landscape of Aspergillus niger at breaking of conidial dormancy revealed by RNA-sequencing
Background
Genome-wide analysis was performed to assess the transcriptional landscape of germinating A. niger conidia using both next generation RNA-sequencing and GeneChips. The metabolism of storage compounds during conidial germination was also examined and compared to the transcript levels from associated genes.
Results
The transcriptome of dormant conidia was shown to be highly differentiated from that of germinating conidia and major changes in response to environmental shift occurred within the first hour of germination. The breaking of dormancy was associated with increased transcript levels of genes involved in the biosynthesis of proteins, RNA turnover and respiratory metabolism. Increased transcript levels of genes involved in metabolism of nitrate at the onset of germination implies its use as a source of nitrogen. The transcriptome of dormant conidia contained a significant component of antisense transcripts that changed during germination.
Conclusion
Dormant conidia contained transcripts of genes involved in fermentation, gluconeogenesis and the glyoxylate cycle. The presence of such transcripts in dormant conidia may indicate the generation of energy from non-carbohydrate substrates during starvation-induced conidiation or for maintenance purposes during dormancy. The immediate onset of metabolism of internal storage compounds after the onset of germination, and the presence of transcripts of relevant genes, suggest that conidia are primed for the onset of germination. For some genes, antisense transcription is regulated in the transition from resting conidia to fully active germinants
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Research-based versus clinical serum creatinine measurements and the association of acute kidney injury with subsequent kidney function: findings from the Chronic Renal Insufficiency Cohort study.
Background:Observational studies relying on clinically obtained data have shown that acute kidney injury (AKI) is linked to accelerated chronic kidney disease (CKD) progression. However, prior reports lacked uniform collection of important confounders such as proteinuria and pre-AKI kidney function trajectory, and may be susceptible to ascertainment bias, as patients may be more likely to undergo kidney function testing after AKI. Methods:We studied 444 adults with CKD who participated in the prospective Chronic Renal Insufficiency Cohort (CRIC) Study and were concurrent members of a large integrated healthcare delivery system. We estimated glomerular filtration rate (eGFR) trajectories using serum creatinine measurements from (i) the CRIC research protocol (yearly) and (ii) routine clinical care. We used linear mixed effects models to evaluate the associations of AKI with acute absolute change in eGFR and post-AKI eGFR slope, and explored whether these varied by source of creatinine results. Models were adjusted for demographic characteristics, diabetes status and albuminuria. Results:During median follow-up of 8.5 years, mean rate of eGFR loss was -0.31 mL/min/1.73 m2/year overall, and 73 individuals experienced AKI (55% Stage 1). A significant interaction existed between AKI and source of serum creatinine for acute absolute change in eGFR level after discharge; in contrast, AKI was independently associated with a faster rate of eGFR decline (mean additional loss of -0.67 mL/min/1.73 m2/year), which was not impacted by source of serum creatinine. Conclusions:AKI is independently associated with subsequent steeper eGFR decline regardless of the serum creatinine source used, but the strength of association is smaller than observed in prior studies after taking into account key confounders such as pre-AKI eGFR slope and albuminuria
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