1,296 research outputs found

    The motivating operation and negatively reinforced problem behavior. A systematic review.

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    The concept of motivational operations exerts an increasing influence on the understanding and assessment of problem behavior in people with intellectual and developmental disability. In this systematic review of 59 methodologically robust studies of the influence of motivational operations in negative reinforcement paradigms in this population, we identify themes related to situational and biological variables that have implications for assessment, intervention, and further research. There is now good evidence that motivational operations of differing origins influence negatively reinforced problem behavior, and that these might be subject to manipulation to facilitate favorable outcomes. There is also good evidence that some biological variables warrant consideration in assessment procedures as they predispose the person's behavior to be influenced by specific motivational operations. The implications for assessment and intervention are made explicit with reference to variables that are open to manipulation or that require further research and conceptualization within causal models

    Implications of landscape configuration on understory forage productivity: a remote sensing assessment of native forests openings

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    Sound management of native forests used for cattle grazing requires understanding the dynamics of forage productivity in the openings. Despite their importance, forage productivity drivers in highly heterogeneous forested landscapes, or their variability over the year, are still unclear. The aim of this work is to find predictors of Normalized Difference Vegetation Index (NDVI) variation in the openings of native temperate forests and to evaluate how these predictors change within the growing season. We used high spatial resolution remote sensing imagery from NW Patagonia to separate forest openings from tree dense canopy. We obtained data of each opening related with herbaceous and shrub forage productivity and calculated landscape metrics. We estimated a multiple linear regression model for predicting NDVI in each season. Beyond known variables related with forage productivity (altitude, precipitation, etc.), the shape of forest’ openings appeared as relevant in predicting NDVI. Higher values of forest opening perimeters were related with a decrease in NDVI in spring when soil water content is not limiting and conversely with an increase in NDVI in summer when water is limiting growth. These results suggest that environmental drivers such as temperature and soil moisture inside the opening, and competition or facilitation process between trees and grasses are mediated by the shape of the opening. Management of heterogeneous native forests for cattle raising requires considering the shape of the openings to maximize forage productivity.Fil: Trinco, Fabio Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural. - Universidad Nacional de Rio Negro. Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural; ArgentinaFil: Rusch, Verónica E.. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Howison, Ruth A.. University of Groningen; Países BajosFil: Garibaldi, Lucas Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural. - Universidad Nacional de Rio Negro. Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural; ArgentinaFil: Tittonell, Pablo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche. Instituto de Investigaciones Forestales y Agropecuarias Bariloche. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; Argentin

    A unique role for 6-O sulfation modification in zebrafish vascular development

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    AbstractHeparan sulfate proteoglycans are important modulators of growth factor signaling in a variety of patterning processes. Secreted growth factors that play critical roles in angiogenesis bind to heparan sulfate, and this association is affected by 6-O-sulfation of the heparan sulfate chains. Addition of 6-O-sulfate is catalyzed by a family of sulfotransferases (HS6STs), and genetic manipulation of their function permits an assessment of their contribution to vascular assembly. We report on the biochemical activity and expression patterns of two zebrafish HS6ST genes. In situ hybridization reveals dynamic and distinct expression patterns of these two genes during development. Structural analysis of heparan sulfate from wild-type and morpholino antisense ‘knockdown’ embryos suggests that HS6ST-1 and HS6ST-2 have similar biochemical activity. HS6ST-2, but not HS6ST-1, morphants exhibit abnormalities in the branching morphogenesis of the caudal vein during embryonic development of the zebrafish. Our finding that HS6ST-2 is required for the branching morphogenesis of the caudal vein is the first in vivo evidence for an essential role of a gene encoding a heparan sulfate modifying enzyme in vertebrate angiogenesis. Our analysis of two zebrafish HS6ST genes suggests that a wide range of biological processes may be regulated by an array of sulfation-modifying enzymes in the vertebrate genome

    Quadrupole collective modes in trapped finite-temperature Bose-Einstein condensates

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    Finite temperature simulations are used to study quadrupole excitations of a trapped Bose-Einstein condensate. We focus specifically on the m=0 mode, where a long-standing theoretical problem has been to account for an anomalous variation of the mode frequency with temperature. We explain this behavior in terms of the excitation of two separate modes, corresponding to coupled motion of the condensate and thermal cloud. The relative amplitudes of the modes depends sensitively on the temperature and on the frequency of the harmonic drive used to excite them. Good agreement with experiment is found for appropriate drive frequencies.Comment: 4 pages, 3 figure

    Modelo de estados y transiciones de los ñirantales del NO de la Patagonia como herramienta para el uso silvopastoril sustentable

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    Desarrollamos un modelo de estados y transiciones (MEyT) para el bosque de ñire (Nothofagus antarctica) en el norte de la Patagonia, con el fin de sintetizar el conocimiento disperso sobre las repuestas de este sistema al manejo silvopastoril. En base a una recopilación bibliográfica, a un taller de expertos seguido por sesiones de consulta y a relevamientos de campo propusimos los estados alternativos e identificamos los disturbios naturales y las prácticas de manejo más comunes que disparan cambios entre estados. Definimos siete estados, 13 transiciones de degradación y cuatro de restauración. Los bosques más íntegros están dominados por ñire y caña (Chusquea culeou) y el estado más degradado lo componen estepas sub-arbustivas de cadillo (Acaena splendens). Los estados intermedios serían los más aptos para el uso silvopastoril (bosque abierto de ñire con caña y pastizal, y bosque de ñire con pastizal), pero tienen una alta inestabilidad con las prácticas de manejo actuales, ya que, a causa de dicho manejo, con el paso del tiempo perderían el componente arbóreo y la cobertura de caña. El pastoreo, la extracción forestal, los incendios y las especies invasoras son los principales factores que disparan las transiciones de degradación. Estos efectos están agravados por la competencia del componente herbáceo con la vegetación arbórea, la mortandad de árboles y de caña, y por la erosión del suelo. La reversión de las transiciones de degradación no se produce de forma natural en el horizonte productivo del predio (~40 años) y requiere del uso de tecnologías como plantación, protección de los plantines de árboles y desarbustado. La identificación de las fases de riesgo en cada estado permite contar con alertas tempranas de deterioro, visualizar los efectos del manejo y orientar las prácticas para mantener la composición y estructura del bosque dentro de los límites que contemplan los aspectos productivo y ambiental. State-and-transition model of ñire forest in NW Patagonia as a tool for sustainable silvopastoral management. We built a state-and-transition model (S&TM) for the ñire forest system under silvopastoral use in north-western Patagonia, with the aim to identify management effects on the vegetation. The model can help design practices that maintain the system within ‘desired’ conditions in the long term. Based on a review of published and unpublished literature, an expert workshop and consultation, and field surveys we proposed alternative states and their response to natural disturbances and current management practices. We defined seven states, 13 degradation and four restoration transitions, and the factors and levels that trigger the transitions (i.e., grazing, firewood extraction, fire and/or dispersal of invasive plants). The best-conserved forest is dominated by ñire (Nothofagus antarctica) and cane (Chusquea couleou), while the most degraded state corresponds to sub-shrubby steppes dominated by Acaena splendens (cadillo). The intermediate states are likely to be the most suitable for silvopastoral use (open ñire and cane forest, and ñire forest with grassland) but are highly unstable. Therefore, with the common current practices, the tree component and cane cover are lost with time. Invasion of exotic species, competition with the herbaceous vegetation, mortality of trees and cane, and soil erosion are the processes that trigger transitions. Most degradation transitions are difficult to revert because they require high-cost practices and/or have a long recovery time. Building the S&TM brought together scattered information about long-term changes in the vegetation. The identification of risk phases enables early warning of degradation.publishedVersio

    Crop diversity benefits carabid and pollinator communities in landscapes with semi-natural habitats

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    In agricultural landscapes, arthropods provide essential ecosystem services such as biological pest control and pollination. Intensified crop management practices and homogenization of landscapes have led to declines among such organisms. Semi-natural habitats, associated with high numbers of these organisms, are increasingly lost from agricultural landscapes but diversification by increasing crop diversity has been proposed as a way to reverse observed arthropod declines and thus restore ecosystem services. However, whether or not an increase in the diversity of crop types within a landscape promotes diversity and abundances of pollinating and predaceous arthropods, and how semi-natural habitats might modify this relationship, are not well understood. To test how crop diversity and the proportion of semi-natural habitats within a landscape are related to the diversity and abundance of beneficial arthropod communities, we collected primary data from seven studies focusing on natural enemies (carabids and spiders) and pollinators (bees and hoverflies) from 154 crop fields in Southern Sweden between 2007 and 2017. Crop diversity within a 1-km radius around each field was positively related to the Shannon diversity index of carabid and pollinator communities in landscapes rich in semi-natural habitats. Abundances were mainly affected by the proportion of semi-natural habitats in the landscape, with decreasing carabid and increasing pollinator numbers as the proportion of this habitat type increased. Spiders showed no response to either crop diversity or the proportion of semi-natural habitats. Synthesis and applications. We show that the joint effort of preserving semi-natural habitats and promoting crop diversity in agricultural landscapes is necessary to enhance communities of natural enemies and pollinators. Our results suggest that increasing the diversity of crop types can contribute to the conservation of service-providing arthropod communities, particularly if the diversification of crops targets complex landscapes with a high proportion of semi-natural habitats

    Temperature Dependence of Damping and Frequency Shifts of the Scissors Mode of a trapped Bose-Einstein Condensate

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    We have studied the properties of the scissors mode of a trapped Bose-Einstein condensate of 87^{87}Rb atoms at finite temperature. We measured a significant shift in the frequency of the mode below the hydrodynamic limit and a strong dependence of the damping rate as the temperature increased. We compared our damping rate results to recent theoretical calculations for other observed collective modes finding a fair agreement. From the frequency measurements we deduce the moment of inertia of the gas and show that it is quenched below the transition point, because of the superfluid nature of the condensed gas.Comment: 5 pages, 4 figure

    Safety, tolerability, and impact on allergic inflammation of autologous E.coli autovaccine in the treatment of house dust mite asthma - a prospective open clinical trial

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    Background: Asthma is increasing worldwide and results from a complex immunological interaction between genetic susceptibility and environmental factors. Autovaccination with E. coli induces a strong TH-1 immune response, thus offering an option for the treatment of allergic diseases. Methods: Prospective open trial on safety, tolerability, and impact on allergic inflammation of an autologous E.coli autovaccine in intermittent or mild persistent house dust mite asthma. Determination of exhaled nitric monoxide (eNO) before and after bronchial mite challenge initially and after nine months of autovaccination. Results: Median eNO increase after autovaccination was significantly smaller (from 27.3 to 33.8 ppb; p=0.334) compared to initial values (from 32.6 to 42.2 ppb; p=0.046) (p=0.034). In nine subjects and a total of 306 injections, we observed 101 episodes of local erythema (33.3%; median of maximal diameter 2.5 cm), 95 episodes of local swelling (31.1%; median of maximal diameter 3 cm), and 27 episodes of local pain (8.8%). Four subjects reported itching at the injection site with a total of 30 episodes (9.8%). We observed no serious adverse events. All organ functions (inclusive electrocardiogramm) and laboratory testing of the blood (clinical chemistry, hematology) and the urine (screening test, B-microglobuline) were within normal limits. Vital signs undulated within the physiological variability. Conclusion: The administration of autologous autovacine for the treatment of house dust mite asthma resulted in a reduction of the eNO increase upon bronchial mite challenge. In nine subjects and 306 injections, only a few mild local reactions and no systemic severe adverse events were observed. EudraCT Nr. 2005-005534-12 ClinicalTrials.gov ID NCT0067720
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