149 research outputs found

    How to Reseed Utah Range Lands

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    Additional low cost forage is urgently needed by Utah\u27s range livestock industry. Seeding of depleted tracts in accordance with recently developed methods and principles will help supply this forage and is entirely feasible. Where the value of the increased forage will repay the cost of planting, careful reseeding of selected sites is fully justified. The important part that reseeding can play in restoring ranges to their former capacity has been demonstrated. Although satisfactory results can be obtained on many sites during average or better years, much more study is needed to insure consistent success in abnormal years and to extend reseeding to all ranges where it is needed. Present information, even when correctly applied, cannot eliminate failures, However, the chances for success will be best if the procedures and principles that have been developed are applied with discrimination and close attention is given to detail

    Cross-Stratification, Dakota Sandstone (Cretaceous), Ottawa County, Kansas

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    Dip bearings of water-deposited cross-strata in sandstone of the Dakota Formation (Cretaceous) of central Kansas were measured at 79 localities in Ottawa County. Vector-resultant (average) dip bearings lie in nearly all compass directions, but average S 57° W, showing that transportation of Dakota sediments in Ottawa County was mainly from northeast to southwest and that the source, therefore, seemingly lay to the northeast. Computation of a regression line of standard deviation on consistency ratio indicates that, in Dakota sandstone, consistency ratio is a good predictor of standard deviation for ratio values between 0.65 and 0.95

    The Orbiter Stability Experiment on STS-40

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    The Orbiter Stability Experiment (OSE) was developed to evaluate the steadiness of the STS Orbiter as a potential platform for instrumentation that would image the Sun in its extreme ultraviolet and soft X-ray radiations. We were interested in any high frequency motions of the Orbiter's orientation due to normal operations and manned activities. Preliminary results are presented of the observations. Other than the expected slow motion of the Orbiter within the specified angular deadband of 0.1 degrees during the observations, it was found that high frequency (above 1 Hz) angular motions (jitter) were not detectable at the 0.25 arc sec detection limit of the most sensitive detector, for most of the period of observation. No high frequency motions were recorded during intervals that were identified with vernier thruster firings. However, one short interval with detectable spectral power to a frequency of 10 Hz has been found to date. It has not yet been correlated with a particular activity going on at the time. The results of the observations may also be of value in assessing perturbations to the Orbiter's micro-gravity environment produced by normal operations

    Modelando las decisiones de un experto a través del aprendizaje basado en decisiones: aplicaciones de la teoría, a la práctica y a la tecnología

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    In higher education, faculty are generally hired for their expertise in the field. They have received extensive training in the discipline but have received limited training in teaching. Thus, they struggle in two ways to teach and develop expertise in novices: First, they are often blind to how their own intuitive expertise functions, and second, they lack a pedagogical strategy to teach their intuitive expert decision-making to students. In this paper, we synthesize the literature on these difficulties for experts. We then discuss how DBL uses cognitive task analysis to help experts make their knowledge explicit and how DBL may be an appropriate pedagogical solution for many university professors. Finally, we provide case studies of DBL in action and discuss how educational technology can support the theory and practice of Decision-based Learning.En la educación universitaria, se contrata a los profesores generalmente por su habilidad de hacer investigaciones. La mayoría de los profesores han recibido una amplia formación en su especialización, pero no han recibido la capacitación adecuada para compartir su conocimiento con sus alumnos. Por lo tanto, se les hace difícil en dos maneras de enseñar y ayudar a sus alumnos a desarrollar una habilidad experta. En primer lugar, a menudo no saben cómo funciona su propio conocimiento intuitivo y, en segundo lugar, carecen de una estrategia pedagógica para enseñar a los alumnos su proceso de tomar decisiones como expertos. En este artículo, sintetizamos la literatura sobre estas dificultades para expertos. Luego, explicamos cómo el Aprendizaje Basado en Decisiones (ABD) usa el análisis de tareas cognitivas para ayudar a los expertos a que hagan explícito su conocimiento. Además, explicamos cómo ABD puede ser una solución pedagógica apropiada para muchos profesores universitarios. Para concluir, hemos proporcionado estudios de caso donde nosotros y otros hemos usado ABD y explicamos cómo la tecnología educativa puede apoyar la teoría y la práctica del aprendizaje basado en decisiones

    Genetic Analysis of Human Immunodefiency Virus Type I Strains in Kenya: A Comparison Using Phylogenetic Analysis and a Combinatorial Melting Assay

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    We surveyed human immunodeficiency virus (HIV) subtype distribution from peripheral blood mononuclear cells (PBMCs) collected in 1995 from 24 HIV-1-infected Kenyan residents (specimens from predominantly male truck drivers and female sex workers near Mombasa and Nairobi). Processed lysates from the PBMC samples were used for env amplification, directly sequenced, and analyzed by phylogenetic analysis. Envelope amplification products were also used for analysis in a polymerase chain reaction (PCR)-based assay, called the combinatorial melting assay (COMA). Results of the two tests were compared for assignment of subtype for this Kenyan cohort. The COMA, a PCR capture technique with colorimetric signal detection, was used with HIV reference subtype strains as well as regional (East Africa) HIV strains for subtype identification. Performance of the COMA was at 100% concordance (24 of 24) as compared with DNA sequencing analysis. Phylogenetic analysis showed 17 isolates to be subtype A, 3 subtype D, and 4 subtype C viruses. This may represent an increase in subtype C presence in Kenya compared with previously documented reports. The COMA can offer advantages for rapid HIV-1 subtype screening of large populations, with the use of previously identified regional strains to enhance the identification of local strains. When more detailed genetic information is desired, DNA sequencing and analysis may be required

    Sexed up: theorizing the sexualization of culture

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    This paper reviews and examines emerging academic approaches to the study of ‘sexualized culture’; an examination made necessary by contemporary preoccupations with sexual values, practices and identities, the emergence of new forms of sexual experience and the apparent breakdown of rules, categories and regulations designed to keep the obscene at bay. The paper maps out some key themes and preoccupations in recent academic writing on sex and sexuality, especially those relating to the contemporary or emerging characteristics of sexual discourse. The key issues of pornographication and democratization, taste formations, postmodern sex and intimacy, and sexual citizenship are explored in detail. </p

    Evaluation of the sub-surface morphology and composition of gunshot residue using focussed ion beam analysis

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    © 2019 Elsevier B.V. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This author accepted manuscript is made available following 12 month embargo from date of publication (January 2019) in accordance with the publisher’s archiving policyRecent work in the forensic analysis of Gunshot residues (GSR) has suggested that the sub-surface or internal composition and morphology of these residues be explored. A particular area of interest is in heavy metal free, or non-toxic ammunition, which are becoming more frequently encountered in the marketplace. As the formulation of the primer compound changes the conditions of the firearm discharge, there is the possibility that different primer formulations may result in the formation of different GSR particles with distinct internal morphologies and compositions. To that end, the internal morphology and composition of GSR particles may provide additional information that could be useful in the investigation of firearms crime. This research investigated the internal morphology of GSR originating from a variety of different ammunition products. Both traditional three-component primed ammunition, and a selection of heavy metal free and non-toxic alternatives were considered. Particles were identified using SEM–EDS, before being cross-sectioned using a focussed ion beam (FIB) instrument. The FIB-sectioned particles were then re-acquired and mapped using SEM–EDS, to assess both internal morphology and composition. Particles observed in this study presented distinct morphological and compositional features at the sub-particle level that may provide an indication of the primer formulation from which they originated. That said, further investigation of a variety of samples should be undertaken to verify the consistency of these features, or any deviations that may be observed based on primer type. However, these results indicate that there may be promise in obtaining additional detail from sub-particle morphology and composition

    Measurement of C_(24)H_(14) Polycyclic Aromatic Hydrocarbons Associated with a Size-Segregated Urban Aerosol

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    Six-ring C_(24)H_(14) (MW 302) polycyclic aromatic hydrocarbons (PAH), some of which are potent mutagens, are present in urban aerosols. Size-segregated atmospheric aerosol samples from Boston, MA, were analyzed for C_(24)H_(14) PAH by gas chromatography/mass spectrometry. Eleven peaks were found with mass to charge ratios of 302; of these, eight were identified using authentic standards. Five of the peaks were quantified. For each of these five, the distributions with respect to particle size were bimodal with the majority of the mass associated with accumulation mode particles (0.3−1.0 μm) and a smaller fraction of the mass associated with ultrafine mode particles (0.09−0.14 μm). These distribu tions are similar to those observed for PAH of molecular weight 252−278 in the same sample but different from those of benzo[ghi]perylene (MW 276) and coronene (MW 300), which were associated to a greater degree with ultrafine particles. The data suggest that C_(24)H_(14) PAH repartition to larger particles by vaporization and sorption more rapidly than do benzo[ghi]perylene and coronene. The total concentration of C_(24)H_(14) PAH (1.5 ng/m^3) was comparable to that of benzo[a]pyrene in the same sample. Because of their mutagenicities, C_(24)H_(14) PAH may make a contribution to the genotoxicity of urban aerosols comparable to that of benzo[a]pyrene

    Measurement of C_(24)H_(14) Polycyclic Aromatic Hydrocarbons Associated with a Size-Segregated Urban Aerosol

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    Six-ring C_(24)H_(14) (MW 302) polycyclic aromatic hydrocarbons (PAH), some of which are potent mutagens, are present in urban aerosols. Size-segregated atmospheric aerosol samples from Boston, MA, were analyzed for C_(24)H_(14) PAH by gas chromatography/mass spectrometry. Eleven peaks were found with mass to charge ratios of 302; of these, eight were identified using authentic standards. Five of the peaks were quantified. For each of these five, the distributions with respect to particle size were bimodal with the majority of the mass associated with accumulation mode particles (0.3−1.0 μm) and a smaller fraction of the mass associated with ultrafine mode particles (0.09−0.14 μm). These distribu tions are similar to those observed for PAH of molecular weight 252−278 in the same sample but different from those of benzo[ghi]perylene (MW 276) and coronene (MW 300), which were associated to a greater degree with ultrafine particles. The data suggest that C_(24)H_(14) PAH repartition to larger particles by vaporization and sorption more rapidly than do benzo[ghi]perylene and coronene. The total concentration of C_(24)H_(14) PAH (1.5 ng/m^3) was comparable to that of benzo[a]pyrene in the same sample. Because of their mutagenicities, C_(24)H_(14) PAH may make a contribution to the genotoxicity of urban aerosols comparable to that of benzo[a]pyrene

    CRT Survey II: a European Society of Cardiology survey of cardiac resynchronisation therapy in 11 088 patients—who is doing what to whom and how?

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    Background: Cardiac resynchronisation therapy (CRT) reduces morbidity and mortality in appropriately selected patients with heart failure and is strongly recommended for such patients by guidelines. A European Society of Cardiology (ESC) CRT survey conducted in 2008–2009 showed considerable variation in guideline adherence and large individual, national and regional differences in patient selection, implantation practice and follow-up. Accordingly, two ESC associations, the European Heart Rhythm Association and the Heart Failure Association, designed a second prospective survey to describe contemporary clinical practice regarding CRT. Methods and results: A survey of the clinical practice of CRT-P and CRT-D implantation was conducted from October 2015 to December 2016 in 42 ESC member countries. Implanting centres provided information about their hospital and CRT service and were asked to complete a web-based case report form collecting information on patient characteristics, investigations, implantation procedures and complications during the index hospitalisation. The 11 088 patients enrolled represented 11% of the total number of expected implantations in participating countries during the survey period; 32% of patients were aged ≥75 years, 28% of procedures were upgrades from a permanent pacemaker or implantable cardioverter-defibrillator and 30% were CRT-P rather than CRT-D. Most patients (88%) had a QRS duration ≥130 ms, 73% had left bundle branch block and 26% were in atrial fibrillation at the time of implantation. Large geographical variations in clinical practice were observed. Conclusion: CRT Survey II provides a valuable source of information on contemporary clinical practice with respect to CRT implantation in a large sample of ESC member states. The survey permits assessment of guideline adherence and demonstrates variations in patient selection, management, implantation procedure and follow-up strategy
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