Soil erosion as affected by shrub encroachment in northeastern Patagonia

La erosion de los suelos es la causa principal de las perdidas irreversibles del potencial productivo de los suelos en la mayoria de los pastizales naturales. En el nordeste de Patagonia, el aumento de la erosion de los suelos ha estado estrechamente asociado al aumento de la cobertura de arbustos en las estepas herbaceas o arbustivas-herbaceas. Nosotros empleamos lluvia simulada para determinar la tasa de infiltracion y la produccion de sedimentos en parches de estepas herbaceas, arbustivas-herbaceas y arbustivas del sitio ecologico Punta Ninfas. Las coberturas de suelo desnudo y de gravas fueron mayores y la cobertura de mantillo menor en la estepa arbustiva respecto a las estepas arbustiva- herbacea y herbacea. En los espacios entre arbustos de la estepa arbustiva, la densidad aparente fue mayor y la macroporosidad y la materia organica fueron menores (P 0.05) que en los monticulos debajo de los arbustos y en las estepas arbustivaherbacea y herbacea. La tasa de infiltration fue un 60 y un 65% mas baja en la estepa arbustiva que en las estepas herbacea y arbustiva-herbacea, respectivamente. Por el contrario, la produccion total y la concentracion de sedimentos fueron mas altas (P s 0.05) en la estepa arbustiva comparado con las estepas herbacea y arbustiva-herbacea. La cobertura de gravas fue la variable que mejor predijo la tasa de infiltracion y la produccion de sedimentos. El contenido de materia organica de los sedimentos, mayormente mantillo, fue similar en la estepa arbustiva y la arbustiva-herbacea y en ambas mayores (P 0.05) que en la estepa herbacea. La remocion de mantillo por el escurrimiento superficial posiblemente represente uno de los procesos que provocan la transicion de la estepa arbustiva-herbacea a la estepa arbustiva. Las altas tasas de remocion de sedimentos, principalmente mantillo, de los espacios entre arbustos de la estepa arbustiva pueden limitar la recuperacion natural de las propiedades fisicas a hidrologicas de los suelos. Estos parches degradados no pueden captar las lluvias incidentes, limitando asi las posibilidades de recuperacion de los pastos perennes y favoreciendo la dominancia de los arbustos.Soil erosion is the primary cause of irreversible loss of soil productivity on most rangelands. In northeastern Patagonia, the increase in soil erosion has been closely associated with the increase in shrub cover in the grass or shrub-grass steppes. We used rainfall simulation to compare infiltration and sediment production from patches of grass, shrub-grass, and shrub steppes of the Punta Ninfas range site. Bare soil and gravel covers were higher and litter cover was lower in the shrub steppe than in the shrub-grass and the grass steppes. In the shrub inter-spaces of the shrub steppe, bulk density was greater and macroporosity and soil organic matter were lower (P less than or equal to 0.05) than in the mounds beneath shrubs and in the grass and shrub-grass areas. Infiltration rate was 60 to 65% lower in the shrub steppe than in the grass and shrub-grass steppes, respectively. On the contrary, total sediment production and concentration were higher (P less than or equal to 0.05) in the shrub steppe as compared to the grass and the shrub-grass areas. Gravel cover was the variable that best predicted infiltration and sediment production. The organic matter content of the sediment, mostly litter, in the shrub and the shrub-grass steppes were similar and greater (P less than or equal to 0.05) than in the grass steppe. Runoff litter removal may represent one of the processes that drive the transition from shrub-grass to shrub steppes. High rates of sediment removal, mainly litter, from the shrub interspaces of the shrub steppe may limit the natural recovery of the soil physical and hydrological properties. These degraded patches fail to capture incident rainfall and restrict the possibilities for the recovery of perennial grasses favoring the dominance of shrubs.Fil: Parizek, B.. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Rostagno, Cesar Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Sottini, Roberto Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentin

Health Literacy and Alcohol Use Behaviors in High School Students

Limited health literacy and alcohol use increase adolescents’ risk for preventable disease burden and adverse outcomes. The Framework for Studying Adolescent Health Literacy (Manganello, 2008) guided this cross-sectional study focused on relationships between high school students’ health literacy and alcohol use. The aims were to describe health literacy in a sample of high school students, explore relationships between health literacy and individual traits, and examine relationships between health literacy and alcohol use. Health literacy was assessed with the Newest Vital Sign. Alcohol use was assessed with questions from the Youth Risk Behavior Survey. An electronic survey was used to collect data from 39 students (response rate = 5.3%, 39/737) attending a private Midwest high school during the spring of 2020. Most students (76.9%, 30/39) had adequate health literacy. Males were more likely to have adequate health literacy than females, but there were no other differences in health literacy based on individual traits. Many students (42.9%, 15/35) reported drinking, and 18.2% (6/33) reported drinking in the past 30 days. Lifetime and current alcohol use were comparable between students with adequate and limited health literacy. There were no differences in alcohol use based on students’ health literacy. Only students with adequate health literacy reported drinking before age 13 years (15.4%, 2/13), drug or alcohol use (42.8%, 3/7) and alcohol use (20.0%, 1/5) before last sexual intercourse. Only students with adequate health literacy reported binge drinking (10.3%, 3/29), riding with someone under the influence (17.9%, 5/28), and drinking and driving (10.5%, 2/19) in the past 30 days. In conclusion, even students with adequate health literacy engage in unsafe alcohol use. Parents, educators, and clinicians need to monitor all students for warning signs of alcohol use and misuse. This study adds evidence about health literacy and alcohol use in students at one high school

Integrating External Hardware on Existing Magnetic Resonance Systems for Commercially Unsupported Applications

Magnetic resonance imaging and spectroscopy provide the potential for breakthroughs in the understanding of disease and evaluation of treatment outcomes in medical conditions such as muscular disorders, cancer, and mental illnesses. Compared to ¹H nuclei, secondary (non-¹H) nuclei such as ¹³C, ³¹P, and ²³Na necessitate higher sensitivity detection methods due to smaller concentrations in vivo and intrinsically lower Larmor frequencies. Two ways to increase the sensitivity of experiments using radiofrequency coils are 1) through optimizing the coil size to fit the volume of interest, and 2) through increasing the number of coils over a defined field of view through phased arrays. Clinical scanners are often constrained in these two regards in that the radiofrequency coils available from the vendor are generally much larger than the volume of interest, and clinical scanners are typically equipped with a singular broadband channel. With these limitations, there is a need to extend the capabilities of existing magnetic resonance systems to increase sensitivity for secondary nuclei and for imaging experiments that fall outside the characteristics of a typical human clinical exam (i.e. small samples, animals, or targeted anatomies). This thesis describes a set of work to address these limitations in order to extend the capabilities of commercial scanners for custom applications. First, the functionality of an existing custom-built multi-channel, broadband receiver is improved through adding calibration capability on each individual channel and through the creation of a user interface that will result in a faster workflow which is critical for live animal experiments. Second, a custom-built double-tuned coil is interfaced to a 3T clinical magnetic resonance imaging system through a custom built connector, increasing the signal-to-noise ratio for the given application in comparison to the currently available coil for the scanner. Both of these projects work towards integrating external hardware on existing systems to increase the sensitivity of multinuclear studies and customized experiments

Analysis and application of ERTS-1 data for regional geological mapping

Combined visual and digital techniques of analysing ERTS-1 data for geologic information have been tried on selected areas in Pennsylvania. The major physiolographic and structural provinces show up well. Supervised mapping, following the imaged expression of known geologic features on ERTS band 5 enlargements (1:250,000) of parts of eastern Pennsylvania, delimited the Diabase Sills and the Precambrian rocks of the Reading Prong with remarkable accuracy. From unsupervised mapping, transgressive linear features are apparent in unexpected density, and exhibit strong control over river valley and stream channel directions. They are unaffected by bedrock type, age, or primary structural boundaries, which suggests they are either rejuvenated basement joint directions on different scales, or they are a recently impressed structure possibly associated with a drifting North American plate. With ground mapping and underflight data, 6 scales of linear features have been recognized

Computer Aided Decision Support for Planning and Management of Research and Development

The aim of the paper is to present the Decision Support System which has been designed to support the management of research and development activities on the national level. The information processing capabilities of such system are discussed as well as possible methodological frameworks including implementation related issues for providing decision support are presented by the authors

Contested multilateralism as credible signaling: how strategic inconsistency can induce cooperation among states

This paper analyzes how patterns of international cooperation are affected if a group of states, led by a major power, pursues a strategy of “contested multilateralism” (CM). We conceptualize CM as a reaction to deadlock in institutional adjustment bargaining where CM lowers the gains actors can reap from cooperation in the short run. We demonstrate that, in the long run, CM nevertheless can have positive effects on international cooperation and specify when this is the case. Because of the costs associated with it, CM conveys a credible signal of the resolve of a dissatisfied group of states to contest the institutional status quo. Due to this capacity, CM alters the institutional and strategic environment within which institutional adjustment bargaining takes place. As a result, CM opens up the possibility for inter-institutional accommodation that increases realized cooperation gains. We probe the plausibility of our theoretical reasoning with empirical case studies on competitive regime creation in multilateral development finance and on regime-shifting in the governance of international trade in genetically modified organisms

Exhaustive testing of safety critical Java

With traditional testing, the test case has no control over non-deterministic scheduling decisions, and thus errors dependent on scheduling are only found by pure chance. Java Path Finder (JPF) is a specialized Java virtual machine that can systematically explore execution paths for all possible schedulings, and thus catch these errors. Unfortunately, execution-based model checkers, including JPF, cannot be easily adapted to support real-time programs. We propose a scheduling algorithm for JPF which allows testing of Safety Critical Java (SCJ) applications with periodic event handlers at SCJ levels 0 and 1 (without aperiodic event handlers). The algorithm requires that deadlines are not missed and that there is an execution time model that can give best- and worst-case execution time estimates for a given program path and specific program inputs. Our implementation, named R SJ, allows to search for scheduling dependent memory access errors, certain invalid argument errors, priority ceiling emulation protocol violations, and failed assertions in application code in SCJ programs for levels 0 and 1. It uses the execution time model of the Java Optimized Processor (JOP). We test our tool wit