2,824 research outputs found

    A Skill Based Approach to Organizing and Cataloguing Supplemental Reading Materials at the Elementary Level

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    This project organized and catalogued all of the supplemental reading materials of an elementary reading room according to a reading skills code list. The code list was developed by consulting reading skills lists and the school district\u27s student learning objectives. Fifteen major skill areas were included in the code list. Each was broken down into subskills which were assigned code numbers. Each supplemental material was examined and catalogued under the appropriate code number. A handbook was compiled which explained the system and listed all of the materials by skill area

    The Y-Band at 1.035 um: Photometric Calibration and the Dwarf Stellar/Sub-Stellar Color Sequence

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    We define and characterize a photometric bandpass (called "Y") that is centered at 1.035 um, in between the traditionally classified ``optical'' and ``infrared'' spectral regimes. We present Y magnitudes and Y-H and Y-K colors for a sample consisting mostly of photometric and spectral standards, spanning the spectral type range sdO to T5V. Deep molecular absorption features in the near-infrared spectra of extremely cool objects are such that the Y-H and Y-K colors grow rapidly with advancing spectral type especially from late M through mid L, substantially more rapidly than J-H or H-K which span a smaller total dynamic range. Consistent with other near-infrared colors, however, Y-H and Y-K colors turn blueward in the L6-L8 temperature range with later T-type objects having colors similar to those of warmer M and L stars. Use of the Y-band filter is nonetheless promising for easy identification of low-mass stars and brown dwarfs, especially at young ages. The slope of the interstellar reddening vector within this filter is A_Y = 0.38 x A_V. Reddening moves stars nearly along the YHK dwarf color sequence making it more difficult to distinguish unambiguously very low mass candidate brown dwarf objects from higher mass stars seen, e.g. through the galactic plane or towards star-forming regions. Other diagrams involving the Y-band may be somewhat more discriminating.Comment: accepted at PAS

    An Experimental Investigation of Wall-Cooling Effects on Hypersonic Boundary-Layer Stability in a Quiet Wind Tunnel

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    One of the primary reasons for developing quiet tunnels is for the investigation of high-speed boundary-layer stability and transition phenomena without the transition-promoting effects of acoustic radiation from tunnel walls. In this experiment, a flared-cone model under adiabatic- and cooled-wall conditions was placed in a calibrated, 'quiet' Mach 6 flow and the stability of the boundary layer was investigated using a prototype constant-voltage anemometer. The results were compared with linear-stability theory predictions and good agreement was found in the prediction of second-mode frequencies and growth. In addition, the same 'N=10' criterion used to predict boundary-layer transition in subsonic, transonic, and supersonic flows was found to be applicable for the hypersonic flow regime as well. Under cooled-wall conditions, a unique set of continuous spectra data was acquired that documents the linear, nonlinear, and breakdown regions associated with the transition of hypersonic flow under low-noise conditions

    Coexistence Curve of Perfluoromethylcyclohexane-Isopropyl Alcohol

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    The coexistence curve of the binary fluid mixture perfluoromethylcyclohexane-isopropyl alcohol was determined by precisely measuring the refractive index both above and below its upper critical consolute point. Sixty-seven two-phase data points were obtained over a wide range of reduced temperatures, 10(exp -5) less than t less than 2.5 x 10(exp -1), to determine the location of the critical point: critical temperature=89.901 C, and critical composition = 62.2% by volume perfluoromethylcyclohexane. These data were analyzed to determine the critical exponent 8 close to the critical point, the amplitude B, and the anomaly in the diameter. The volume-fraction coexistence curve is found to be as symmetric as any composition like variable. Correction to scaling is investigated as well as the need for a crossover theory. A model is proposed that describes the asymptotic approach to zero of the effective exponent Beta, which allows an estimation of the temperature regime free of crossover effects

    A human testicular teratoma serially transplanted in immune-deprived mice.

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    Serial transplantation of an HCG-producing human testicular teratoma in immune-deprived mice is described. The xenografted tumour was compared to the tumour of origin in histology, immunohistochemistry (using an immune peroxidase technique to localize HCG) autoradiography, marker production and growth rate. It is concluded that the xenograft retained the characteristics of the original tumour with the exception of a reduction in HCG-producing elements at transplantation beyond 5 serial passages

    Time symmetry in quantum theories and beyond

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    There is a stark tension among different formulations of quantum theory in that some are fundamentally time-symmetric and others are radically time-asymmetric. This tension is crisply captured when thinking of physical theories as theories of processes. We review process theories and their diagrammatic representation, and show how quantum theory can be described in this language. The tension between time-symmetry and time-asymmetry is then captured by the tension between two of the key structures that are used in this framework. On the one hand, the symmetry is captured by a dagger structure, which is represented by a reflection of diagrams. On the other hand, the asymmetry is captured by a condition involving discarding which, ultimately, is responsible for the theory being compatible with relativistic causality. Next we consider three different ways in which we this tension can be resolved. The first of these is closely related to recent work of Lucien Hardy, where the tension is resolved by adding in a time reversed version of discarding together with a suitable consistency condition. The second is, to our knowledge, a new approach. Here the tension is resolved by adding in new systems which propagate backwards in time, and imposing a consistency condition to avoid running into well known time-travel paradoxes. The final approach that we explore is closely related to work of Oreshkov and Cerf, where the tension is resolved by removing the constraint associated with discarding. We show two equivalent ways in which this can be done whilst ensuring that the resulting theory still makes sensible operational predictions.Comment: 38 pages, many diagrams, comments welcome

    A Daily Diary Analysis of Condom Breakage and Slippage during Vaginal Sex or Anal Sex among Adolescent Women

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    Background Adolescent women Adolescent women are disproportionately impacted by the adverse outcomes associated with sexual activity, including sexually transmitted infections (STI). Condoms as a means of prevention relies upon use that is free of usage failure, including breakage and/or slippage. This study examined the daily prevalence of and predictors of condom breakage and/or slippage during vaginal sex and during anal sex among adolescent women. Methods Adolescent women (N=387; 14 to 17 years) were recruited from primary care clinics for a longitudinal cohort study of STIs and sexual behavior. Data were daily partner-specific sexual diaries. Random intercept mixed effects logistic regression was used to estimate the fixed effect of each predictor on condom breakage/slippage during vaginal or during anal sex (Stata, 13.0), adjusting model coefficients for the correlation between repeated within-participant diary entries. Results Condom slippage and/or breakage varied across sexual behaviors and was associated with individual-specific (e.g., age and sexual interest) and partner-specific factors (e.g., negativity). Recent behavioral factors (e.g., experiencing slippage and/or breakage in the past week) were the strongest predictors of current condom slippage and/or breakage during vaginal or anal sex Conclusion Factors associated with young women’s condom breakage/slippage during vaginal or during anal sex should be integrated as part of STI prevention efforts, and should be assessed as part of ongoing routine clinical care

    Liver transplantation for type IV glycogen storage disease

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    TYPE IV glycogen storage disease is a rare autosomal recessive disorder (also called Andersen's disease1 or amylopectinosis) in which the activity of branching enzyme alpha-1, 4-glucan: alpha-1, 4-glucan 6-glucosyltransferase is deficient in the liver as well as in cultured skin fibroblasts and other tissues.2,3 This branching enzyme is responsible for creating branch points in the normal glycogen molecule. In the relative or absolute absence of this enzyme, an insoluble and irritating form of glycogen, an amylopectin-like polysaccharide that resembles plant starch, accumulates in the cells. The amylopectin-like form is less soluble than normal glycogen, with longer outer and inner chains. © 1991, Massachusetts Medical Society. All rights reserved

    A quiet tunnel investigation of hypersonic boundary-layer stability over a cooled, flared cone

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    A flared-cone model under adiabatic and cooled-wall conditions was placed in a calibrated, low-disturbance Mach 6 flow and the stability of the boundary layer was investigated using a prototype constant-voltage anemometer. The results were compared with linear-stability theory predictions and good agreement was found in the prediction of second-mode frequencies and growth. In addition, the same 'N = 10' criterion used to predict boundary-layer transition in subsonic, transonic, and supersonic flows under low freestream noise conditions was found to be applicable for the hypersonic flow regime as well. Under cooled-wall conditions, a unique set of spectral data was acquired that documents the linear, nonlinear, and breakdown regions associated with the transition of hypersonic flow under low-noise conditions
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