469 research outputs found
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La colombella, il giglio (1904)
Luigi Ferrare Trecate
La colombella, il giglio (1904)
text by Heinrich Heine, Poem 3 of Lyrisches Intermezzo (Buch der Lieder
Identifying discriminating items for student feedback to principals
The primary purpose of this study was to create and test items for student evaluation of principal performance. The items were designed utilizing the five correlates of the effective school and current research on principal behaviors as defined by the School Improvement Model Project at Iowa State University;The study involved 599 students in grades 5, 8, and 11 representing 32 schools from 24 public school districts and one Roman Catholic Diocese during the fall semester of the 1989-90 school year. Samples were drawn from each grade level to test various hypotheses;The data from the questionnaires were analyzed using the Menne and Tolsma methodology to determine item discrimination power. Items which discriminated at the.05 level of significance were identified. Items on the two sections of the questionnaire that were found to be discriminating between principals were analyzed to determine the correlation between student responses on the discrimination questionnaire and the potentially biasing factors of the student\u27s like or dislike of the principal, attendance patterns, and their interest in school;It was hypothesized that differences in item discrimination power would be identified in the analysis of data between male and female principals, public and nonpublic school principals, principals of large and small schools, and between participating grade levels (5, 8, and 11);Students rated the performance of female principals more favorably on items involving instructional leadership while their male counterparts were perceived to operate a safer and more orderly school environment. Nonpublic school principals were perceived to interact more frequently with students and run a safer and more orderly school environment. Students from small schools (less than 350 students) perceived their principal to be more involved in student activities and overall demonstrated a more caring attitude. Overall, fifth grade students rated the performance of their principal more favorably than grade 8 or grade 11 students
A Multi-Institutional Analysis of Instructional Beliefs and Practices in Gateway Courses to the Sciences
This paper builds on previous studies of instructional practice in science, technology, engineering, and mathematics courses by reporting findings from a study of the relationship between instructors’ beliefs about teaching and learning and their observed classroom practices. Data collection took place across six institutions of higher education and included in-depth interviews with 71 instructors and more than 140 hours of classroom observations using the Teaching Dimensions Observation Protocol. Thematic coding of interviews identified 31 distinct beliefs that instructors held about the ways students best learn introductory concepts and skills in these courses. Cluster analysis of the observation data suggested that their observable practices could be classified into four instructional styles. Further analysis suggested that these instructional styles corresponded to disparate sets of beliefs about student learning. The results add momentum to reform efforts that simultaneously approach instructional change in introductory courses as a dynamic relationship between instructors’ subjective beliefs about teaching and learning and their strategies in the classroom
Intergenerational Education Mobility Trends by Race and Gender in the United States
Researchers have examined racial and gender patterns of intergenerational education mobility, but less attention has been given to the ways that race and gender interact to further shape these relationships. Based on data from the General Social Survey, this study examined the trajectories of education mobility among Blacks and Whites by gender over the past century. Ordinary least squares and logistic regression models revealed three noteworthy patterns. First, Black men and women have closed substantial gaps with their White counterparts in intergenerational education mobility. At relatively low levels of parental education, these gains have been experienced equally among Black men and women. However, Black men are most disadvantaged at the highest levels of parental education relative to Black women and Whites in general. Finally, the advantages in education mobility experienced by White men in the early and midpart of the 20th century have largely eroded. White women, in contrast, have made steady gains in education mobility across a variety of parental education levels
Has the Elite Foundation Agenda Spread Beyond the Gates? An Organizational Network Analysis of Nonmajor Philanthropic Giving in K-12 Education
Previous research focusing on major philanthropic foundations suggests that these actors have collectively converged around a set of jurisdictional challengers promoting market-based education reforms. Using correspondence analysis, network analysis, and geographic information science, this article empirically tests whether this convergence has permeated to less prominent foundations and their grantees, or if these foundations are pursuing alternative organizational strategies to shape K–12 outcomes. The analysis draws from a sample of 15 nonmajor foundations and their 1,069 grantees serving some aspect of K–12 education in 2010. We find that nonmajor foundations have adopted some elements of major foundations’ organizational strategies to influence K–12 education but that their strategies are heterogeneous and reflect both challenges to—and opportunities for—a more varied and democratic structure of policy making
Characterizing Aerosol Distributions and Optical Properties Using the NASA Langley High Spectral Resolution Lidar
The objective of this project was to provide vertically and horizontally resolved data on aerosol optical properties to assess and ultimately improve how models represent these aerosol properties and their impacts on atmospheric radiation. The approach was to deploy the NASA Langley Airborne High Spectral Resolution Lidar (HSRL) and other synergistic remote sensors on DOE Atmospheric Science Research (ASR) sponsored airborne field campaigns and synergistic field campaigns sponsored by other agencies to remotely measure aerosol backscattering, extinction, and optical thickness profiles. Synergistic sensors included a nadir-viewing digital camera for context imagery, and, later in the project, the NASA Goddard Institute for Space Studies (GISS) Research Scanning Polarimeter (RSP). The information from the remote sensing instruments was used to map the horizontal and vertical distribution of aerosol properties and type. The retrieved lidar parameters include profiles of aerosol extinction, backscatter, depolarization, and optical depth. Products produced in subsequent analyses included aerosol mixed layer height, aerosol type, and the partition of aerosol optical depth by type. The lidar products provided vertical context for in situ and remote sensing measurements from other airborne and ground-based platforms employed in the field campaigns and was used to assess the predictions of transport models. Also, the measurements provide a data base for future evaluation of techniques to combine active (lidar) and passive (polarimeter) measurements in advanced retrieval schemes to remotely characterize aerosol microphysical properties. The project was initiated as a 3-year project starting 1 January 2005. It was later awarded continuation funding for another 3 years (i.e., through 31 December 2010) followed by a 1-year no-cost extension (through 31 December 2011). This project supported logistical and flight costs of the NASA sensors on a dedicated aircraft, the subsequent analysis and archival of the data, and the presentation of results in conferences, workshops, and publications. DOE ASR field campaigns supported under this project included - MAX-Mex /MILAGRO (2006) - TexAQS 2006/GoMACCS (2006) - CHAPS (2007) - RACORO (2009) - CARE/CalNex (2010) In addition, data acquired on HSRL airborne field campaigns sponsored by other agencies were used extensively to fulfill the science objectives of this project and the data acquired have been made available to other DOE ASR investigators upon request
Algorithm for Atmospheric Corrections of Aircraft and Satellite Imagery
A simple and fast atmospheric correction algorithm is described which is used to correct radiances of scattered sunlight measured by aircraft and/or satellite above a uniform surface. The atmospheric effect, the basic equations, a description of the computational procedure, and a sensitivity study are discussed. The program is designed to take the measured radiances, view and illumination directions, and the aerosol and gaseous absorption optical thickness to compute the radiance just above the surface, the irradiance on the surface, and surface reflectance. Alternatively, the program will compute the upward radiance at a specific altitude for a given surface reflectance, view and illumination directions, and aerosol and gaseous absorption optical thickness. The algorithm can be applied for any view and illumination directions and any wavelength in the range 0.48 micron to 2.2 micron. The relation between the measured radiance and surface reflectance, which is expressed as a function of atmospheric properties and measurement geometry, is computed using a radiative transfer routine. The results of the computations are presented in a table which forms the basis of the correction algorithm. The algorithm can be used for atmospheric corrections in the presence of a rural aerosol. The sensitivity of the derived surface reflectance to uncertainties in the model and input data is discussed
Assembly of heteropolymers via a network of reaction coordinates
In biochemistry, heteropolymers encoding biological information are assembled out of equilibrium by sequentially incorporating available monomers found in the environment. Current models of polymerization treat monomer incorporation as a sequence of discrete chemical reactions between intermediate metastable states. In this paper, we use ideas from reaction rate theory and describe nonequilibrium assembly of a heteropolymer via a continuous reaction coordinate. Our approach allows for estimating the copy error and incorporation speed from the Gibbs free energy landscape of the process. We apply our theory to several examples from a simple reaction characterized by a free energy barrier to more complex cases incorporating error correction mechanisms, such as kinetic proofreading
Using policy network analysis to understand ideological convergence and change in educational subsystems
In recent years, education policy scholars have begun to utilize social network concepts and methods to describe contemporary policy changes across P-16 levels. While many insights have emerged from this growing literature base, we argue that a more formal network approach rooted in policy network analysis (PNA) is needed to fulfill its conceptual and analytical ambitions. Policy network analysis integrates concepts from social network analysis with theoretical assumptions developed in the field of political science. Toward this end, we first argue that a more rigorous treatment of policy beliefs is needed to analyze the impact of ideas on the policy agenda. Existing literature on the ideological dimensions of market-based reform movements tends to define them largely within the bounds of neo-liberalism and thus far has failed to systematically explain how policy beliefs emerge and converge in this context. Second, we contend that previous work has generally lacked theoretical grounding in formal policy network analysis (PNA). Although there are clear links between the concepts and findings in traditional PNA literature and educational research – particularly the use of networked governance as a concept for understanding the interconnectedness of educational reform networks – a more diligent application of PNA theory and methods would enable educational policy scholars to gain deeper insights into the explanatory processes of policy change. We pay particular attention to the usefulness of these approaches for examining two-mode network data and for modeling ideological policy change.En los últimos años, los académicos de las políticas educativas han comenzado a utilizar conceptos y métodos de redes sociales para describir los cambios políticos contemporáneos en los niveles P-16, pero se necesita un enfoque de red más formal arraigado en el análisis de redes de políticas (ANP). El análisis de redes de políticas integra conceptos del análisis de redes sociales con supuestos teóricos desarrollados en el campo de las ciencias políticas. A pesar de los vínculos entre los conceptos y los hallazgos en la literatura tradicional de la ANP y la investigación educativa, en particular el uso de la gobernanza en red como concepto para comprender la interconexión de las redes de reforma educativa, una aplicación más diligente de la teoría y los métodos de la ANP permitiría a los académicos de la política educativa profundizar conocimientos sobre los procesos explicativos del cambio de políticas. Prestamos especial atención a la utilidad de estos enfoques para examinar datos de red de dos modos y para modelar cambios de políticas ideológicas.Nos últimos anos, estudiosos de políticas educacionais começaram a utilizar conceitos e métodos de redes sociais para descrever mudanças políticas contemporâneas em todos os níveis P-16, embora seja necessária uma abordagem de rede mais formal enraizada na análise de redes políticas (PNA). A análise de redes políticas integra conceitos da análise de redes sociais com pressupostos teóricos desenvolvidos no campo da ciência política. Apesar das ligações entre os conceitos e descobertas na literatura tradicional de PNA e a pesquisa educacional - particularmente o uso de governança em rede como um conceito para compreender a interconexão das redes de reforma educacional - uma aplicação mais diligente da teoria e dos métodos de PNA permitiria que estudiosos de políticas educacionais se aprofundassem percepções sobre os processos explicativos de mudança de política. Prestamos atenção especial à utilidade dessas abordagens para examinar dados de rede de dois modos e para modelar mudanças ideológicas nas políticas
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3+2 + X: what is the most useful depolarization input for retrieving microphysical properties of non-spherical particles from lidar measurements using the spheroid model of Dubovik et al. (2006)?
The typical multiwavelength aerosol lidar data set for inversion of optical to microphysical parameters is composed of three backscatter coefficients (β) at 355, 532, and 1064 nm and two extinction coefficients (α) at 355 and 532 nm. This data combination is referred to as a 3β+2α or 3+2 data set. This set of data is sufficient for retrieving some important microphysical particle parameters if the particles have spherical shape. Here, we investigate the effect of including the particle linear depolarization ratio (δ) as a third input parameter for the inversion of lidar data. The inversion algorithm is generally not used if measurements show values of δ that exceed 0.10 at 532 nm, i.e. in the presence of non-spherical particles such as desert dust, volcanic ash, and, under special circumstances, biomass-burning smoke. We use experimental data collected with instruments that are capable of measuring δ at all three lidar wavelengths with an inversion routine that applies the spheroidal light-scattering model of Dubovik et al. (2006) with a fixed axis-ratio distribution to replicate scattering properties of non-spherical particles. The inversion gives the fraction of spheroids required to replicate the optical data as an additional output parameter. This is the first systematic test of the effect of using all theoretically possible combinations of δ taken at 355, 532, and 1064 nm as input in the lidar data inversion. We find that depolarization information of at least one wavelength already provides useful information for the inversion of optical data that have been collected in the presence of non-spherical mineral dust particles. However, any choice of δλ will give lower values of the single-scattering albedo than the traditional 3+2 data set. We find that input data sets that include δ355 give a spheroid fraction that closely resembles the dust ratio we obtain from using β532 and δ532 in a methodology applied in aerosol-type separation. The use of δ355 in data sets of two or three δλ reduces the spheroid fraction that is retrieved when using δ532 and δ1064. Use of the latter two parameters without accounting for δ355 generally leads to high spheroid fractions that we consider not trustworthy. The use of three δλ instead of two δλ, including the constraint that one of these is measured at 355 nm does not provide any advantage over using 3+2+δ355 for the observations with varying contributions of mineral dust considered here. However, additional measurements at wavelengths different from 355 nm would be desirable for application to a wider range of aerosol scenarios that may include non-spherical smoke particles, which can have values of δ355 that are indistinguishable from those found for mineral dust. We therefore conclude that – depending on measurement capability – the future standard input for inversion of lidar data taken in the presence of mineral dust particles and using the spheroid model of Dubovik et al. (2006) might be 3+2+δ355 or 3+2+δ355+δ532.Peer reviewe
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