1,233 research outputs found

    The Response of Selected Temperate Forages to Increasing Summer Drought Conditions and High Summer Temperatures in Northern Victoria, Australia

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    In the dairy region of northern Victoria, Australia, the performance of temperate perennial dairy pastures is often poor over summer due to a combination of high temperatures and limited water availability that can restrict dry matter production and plant survival. A series of field experiments examined the effects of heat and restricted irrigation (as a consequence of drought) on the growth and nutritive characteristics of selected forage species, and whether survival under experimental conditions was influenced by plant genotype, irrigation and grazing management strategies, as well as endophyte presence. The major focus was on perennial ryegrass. Detailed sampling of perennial ryegrass (Lolium perenne L.), lucerne (Medicago sativa L.) and tall fescue (Festuca arundinacea Schreb) pastures on commercial farms during five extreme heat events (\u3e 35 oC) over summer 2018/2019, highlighted the impact of high temperatures on pasture nutritive parameters. In vitro dry matter digestibility and water soluble carbohydrate concentrations decreased by 0.2% units per degree rise in average maximum daily temperature from 23 to 40 ÂșC and neutral detergent fibre and acid detergent fibre concentrations increased by 0.2% and 0.15% units per degree, respectively. When a range of perennial ryegrass cultivars, hybrid ryegrasses and tall fescue cultivars were evaluated under full and restricted irrigation and two grazing strategies, few differences in net pasture accumulation over summer or survival were observed. The research highlighted the importance of maintaining plant density during periods of restricted irrigation to ensure plant recovery once irrigation or rainfall becomes available. No endophyte-ryegrass combinations were found to be better adapted to restricted water and high temperature conditions. The incidences of extreme heat events and low water availability are increasing in northern Victoria and this research will assist farmers to identify strategies to mitigate the negative effect of these conditions on the production and feed quality of perennial ryegrass-based pastures

    New procedures for testing whether stock price processes are martingales

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    We propose procedures for testing whether stock price processes are martingales based on limit order type betting strategies. We first show that the null hypothesis of martingale property of a stock price process can be tested based on the capital process of a betting strategy. In particular with high frequency Markov type strategies we find that martingale null hypotheses are rejected for many stock price processes

    The Secret to Successful User Communities: An Analysis of Computer Associates’ User Groups

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    This paper provides the first large scale study that examines the impact of both individual- and group-specific factors on the benefits users obtain from their user communities. By empirically analysing 924 survey responses from individuals in 161 Computer Associates' user groups, this paper aims to identify the determinants of successful user communities. To measure success, the amount of time individual members save through having access to their user networks is used. As firms can significantly profit from successful user communities, this study proposes four key implications of the empirical results for the management of user communities

    What makes you not a Buddhist? : a preliminary mapping of values

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    This study sets out to establish which Buddhist values contrasted with or were shared by adolescents from a non-Buddhist population. A survey of attitude toward a variety of Buddhist values was fielded in a sample of 352 non-Buddhist schoolchildren aged between 13 and 15 in London. Buddhist values where attitudes were least positive concerned the worth of being a monk/nun or meditating, offering candles & incense on the Buddhist shrine, friendship on Sangha Day, avoiding drinking alcohol, seeing the world as empty or impermanent and Nirvana as the ultimate peace. Buddhist values most closely shared by non-Buddhists concerned the Law of Karma, calming the mind, respecting those deserving of respect, subjectivity of happiness, welfare work, looking after parents in old age and compassion to cuddly animals. Further significant differences of attitude toward Buddhism were found in partial correlations with the independent variables of sex, age and religious affiliation. Correlation patterns paralleled those previously described in theistic religions. Findings are applied to spiritual, moral, social and cultural development and for the teaching of religious to pupils of no faith adherence. The study recommends that quantitative psychometrics employed to conceptualize Buddhist values by discriminant validity in this study could be extended usefully to other aspects of the study of Buddhism, particularly in quest of validity in the conceptualization of Buddhist identity within specifically Buddhist populations

    Neonatal brain tissue classification with morphological adaptation and unified segmentation

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    Measuring the distribution of brain tissue types (tissue classification) in neonates is necessary for studying typical and atypical brain development, such as that associated with preterm birth, and may provide biomarkers for neurodevelopmental outcomes. Compared with magnetic resonance images of adults, neonatal images present specific challenges that require the development of specialized, population-specific methods. This paper introduces MANTiS (Morphologically Adaptive Neonatal Tissue Segmentation), which extends the unified segmentation approach to tissue classification implemented in Statistical Parametric Mapping (SPM) software to neonates. MANTiS utilizes a combination of unified segmentation, template adaptation via morphological segmentation tools and topological filtering, to segment the neonatal brain into eight tissue classes: cortical gray matter, white matter, deep nuclear gray matter, cerebellum, brainstem, cerebrospinal fluid (CSF), hippocampus and amygdala. We evaluated the performance of MANTiS using two independent datasets. The first dataset, provided by the NeoBrainS12 challenge, consisted of coronal T2-weighted images of preterm infants (born ≀30 weeks’ gestation) acquired at 30 weeks’ corrected gestational age (n= 5), coronal T2-weighted images of preterm infants acquired at 40 weeks’ corrected gestational age (n= 5) and axial T2-weighted images of preterm infants acquired at 40 weeks’ corrected gestational age (n= 5). The second dataset, provided by the Washington University NeuroDevelopmental Research (WUNDeR) group, consisted of T2-weighted images of preterm infants (born <30 weeks’ gestation) acquired shortly after birth (n= 12), preterm infants acquired at term-equivalent age (n= 12), and healthy term-born infants (born ≄38 weeks’ gestation) acquired within the first nine days of life (n= 12). For the NeoBrainS12 dataset, mean Dice scores comparing MANTiS with manual segmentations were all above 0.7, except for the cortical gray matter for coronal images acquired at 30 weeks. This demonstrates that MANTiS’ performance is competitive with existing techniques. For the WUNDeR dataset, mean Dice scores comparing MANTiS with manually edited segmentations demonstrated good agreement, where all scores were above 0.75, except for the hippocampus and amygdala. The results show that MANTiS is able to segment neonatal brain tissues well, even in images that have brain abnormalities common in preterm infants. MANTiS is available for download as an SPM toolbox from http://developmentalimagingmcri.github.io/mantis

    Doing fence sitting: a discursive analysis of clinical psychologists' constructions of mental health

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    A growing body of research indicates that the way health care professionals conceptualize mental health might have important clinical implications. We adopted a discursive psychology approach to explore clinical psychologists’ accounts of mental health and its effects. Semistructured interviews were conducted with 11 clinical psychologists in the East Midlands region of the United Kingdom. The participants constructed mental health through building up biological factors and psychosocial aspects as opposite ends of the same spectrum, and then positioned themselves as distant from these extremes to manage issues of stake and accountability. A discourse of moral concern for service users was used to negotiate the implications of having different views of mental health from service users, enabling clinicians to manage issues of accountability and demonstrate their ability to be helpful. This suggests that clinicians should be mindful of the effects of their use of language and make the contingent nature of their knowledge explicit

    The α(1,3)fucosyltransferases FucT-IV and FucT-VII Exert Collaborative Control over Selectin-Dependent Leukocyte Recruitment and Lymphocyte Homing

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    AbstractE-, P-, and L-selectin counterreceptor activities, leukocyte trafficking, and lymphocyte homing are controlled prominently but incompletely by α(1,3)fucosyltransferase FucT-VII-dependent fucosylation. Molecular determinants for FucT-VII-independent leukocyte trafficking are not defined, and evidence for contributions by or requirements for other FucTs in leukocyte recruitment is contradictory and incomplete. We show here that inflammation-dependent leukocyte recruitment retained in FucT-VII deficiency is extinguished in FucT-IV−/−/FucT-VII−/− mice. Double deficiency yields an extreme leukocytosis characterized by decreased neutrophil turnover and increased neutrophil production. FucT-IV also contributes to HEV-born L-selectin ligands, since lymphocyte homing retained in FucT-VII−/− mice is revoked in FucT-IV−/−/FucT-VII−/− mice. These observations reveal essential FucT-IV-dependent contributions to E-, P-, and L-selectin ligand synthesis and to the control of leukocyte recruitment and lymphocyte homing

    Monitoring international migration flows in Europe. Towards a statistical data base combining data from different sources

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    The paper reviews techniques developed in demography, geography and statistics that are useful for bridging the gap between available data on international migration flows and the information required for policy making and research. The basic idea of the paper is as follows: to establish a coherent and consistent data base that contains sufficiently detailed, up-to-date and accurate information, data from several sources should be combined. That raises issues of definition and measurement, and of how to combine data from different origins properly. The issues may be tackled more easily if the statistics that are being compiled are viewed as different outcomes or manifestations of underlying stochastic processes governing migration. The link between the processes and their outcomes is described by models, the parameters of which must be estimated from the available data. That may be done within the context of socio-demographic accounting. The paper discusses the experience of the U.S. Bureau of the Census in combining migration data from several sources. It also summarizes the many efforts in Europe to establish a coherent and consistent data base on international migration. The paper was written at IIASA. It is part of the Migration Estimation Study, which is a collaborative IIASA-University of Groningen project, funded by the Netherlands Organization for Scientific Research (NWO). The project aims at developing techniques to obtain improved estimates of international migration flows by country of origin and country of destination

    Why Map Issues? On Controversy Analysis as a Digital Method

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    This paper takes stock of recent efforts to implement controversy analysis as a digital method, in the study of science, technology and society (STS) and beyond, and outlines a distinctive approach to addressing a key challenge: the problem of digital bias. Digital media technologies exert significant influence on the enactment of controversy in online settings, and this risks to undermine the substantive focus of controversy analysis conducted by digital means. To address this problem, I propose a shift in thematic focus from controversy analysis to issue mapping. The paper begins by distinguishing between three broad frameworks that currently guide the development of controversy analysis as a digital method: demarcationist, discursive and empiricist. While each of these frameworks has been adopted in STS, I argue that the last one offers the best opportunities to further develop its distinctive approach to controversy analysis and address the problem of digital bias: this last framework allows us to digitally implement the “move beyond impartiality” in the study of knowledge, technology and society. To clarify how, I distinguish between two opposing solutions to the problem of digital bias in controversy analysis: a precautionary approach that seeks to render controversy independent from digital platforms, and an affirmative approach, which deploys specifically digital formats such as hyperlinks and hashtags to map controversies. Endorsing the latter approach, I argue that it needs to be developed further in order to secure the substantive focus of digital controversy analysis. We must broaden the scope of digital controversy analysis and examine not just controversies, but a broader range of issue formations, including public relations campaigns and activist mobilizations. I explore the practical implementation of this approach by discussing a pilot study in which we analyzed issues of Internet governance with the social media platform Twitter

    Identifying risks for male street gang affiliation: a systematic review and narrative synthesis

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    Gang violence has increased in recent years. Individuals are becoming gang affiliated younger, and many have suffered historic maltreatment. Subsequent exposure to violence can result in profound consequences, including acute psychological harm. This review aims to identify predictive risk factors for male street gang affiliation. A systematic literature search was conducted utilising PsycINFO, PsycARTICLES, Medline, the Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews and the Social Policy and Practice databases (from the databases’ inception to 03/04/15). From this search, n=244 peer-reviewed papers were included in an initial scoping review, and n=102 thereafter met criteria for a systematic review; a narrative synthesis follows. Gang members have typically faced numerous historic adversities across multiple domains; individual, family, peers, school and community. Cumulative factors generated an independent risk. The meta-narrative described an overarching failure to safeguard vulnerable individuals, with the motivation for gang affiliation hypothetically arising from an attempt to have their basic needs met. Clinical and research recommendations were made to inform early intervention policy and practice
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