30 research outputs found

    Secondary Structures in Long Compact Polymers

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    Compact polymers are self-avoiding random walks which visit every site on a lattice. This polymer model is used widely for studying statistical problems inspired by protein folding. One difficulty with using compact polymers to perform numerical calculations is generating a sufficiently large number of randomly sampled configurations. We present a Monte-Carlo algorithm which uniformly samples compact polymer configurations in an efficient manner allowing investigations of chains much longer than previously studied. Chain configurations generated by the algorithm are used to compute statistics of secondary structures in compact polymers. We determine the fraction of monomers participating in secondary structures, and show that it is self averaging in the long chain limit and strictly less than one. Comparison with results for lattice models of open polymer chains shows that compact chains are significantly more likely to form secondary structure.Comment: 14 pages, 14 figure

    The U.S. Arctic Observing Viewer: A Web-Mapping Application for Enhancing Environmental Observation of the Changing Arctic

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    Although much progress has been made with various Arctic Observing efforts, assessing that progress can be difficult. What data collection efforts are established or underway? Where? By whom? To help meet the strategic needs of programs such as the U.S. Study of Environmental Arctic Change (SEARCH), the Arctic Observing Network (AON), Sustaining Arctic Observing Networks (SAON) and related initiatives, an update has been released for the Arctic Observing Viewer (AOV; http://ArcticObservingViewer.org). This web mapping application and information system has begun to compile the who, what, where, and when for thousands of data collection sites (such as boreholes, ship tracks, buoys, towers, sampling stations, sensor networks, vegetation sites, stream gauges, and observatories) wherever marine, terrestrial, or atmospheric data are collected. Contributing partners for this collaborative resource include the U.S. NSF, ACADIS, ADIwg, AOOS, a2dc, AON, ARMAP, BAID, CAFF, IASOA, INTERACT, and others. While focusing on U.S. activities, the AOV welcomes information exchange with international groups for mutual benefit. Users can visualize, navigate, select, search, draw, print, and more. AOV is founded on principles of interoperability, with open metadata and web service standards, so that agencies and organizations can use AOV tools and services for their own purposes. In this way, AOV will reinforce and complement other distributed yet interoperable cyber-resources and will help science planners, funding agencies, researchers, data specialists, and others to assess status, identify overlap, fill gaps, optimize sampling design, refine network performance, clarify directions, access data, coordinate logistics, collaborate, and more in order to meet Arctic Observing goals.MalgrĂ© les progrĂšs rĂ©alisĂ©s dans le cadre de nombreux efforts d’observation de l’Arctique, les progrĂšs peuvent ĂȘtre difficiles Ă  Ă©valuer. Quelles initiatives de collecte de donnĂ©es sont en cours ou sont Ă©tablies? À quel endroit? Et qui gĂšre ces initiatives? Pour aider Ă  rĂ©pondre aux besoins stratĂ©giques de programmes comme ceux de l’organisme amĂ©ricain Study of Environmental Arctic Change (SEARCH), du rĂ©seau Arctic Observing Network (AON), des rĂ©seaux Sustaining Arctic Observing Networks (SAON) et d’autres programmes connexes, on a procĂ©dĂ© Ă  la mise Ă  jour de l’Arctic Observing Viewer (AOV; http://ArcticObservingViewer.org). Ce systĂšme d’information jumelĂ© Ă  une application de mappage sur le Web a amorcĂ© la compilation des coordonnĂ©es et des renseignements se rapportant Ă  des milliers de sites de collecte de donnĂ©es (comme les trous de forage, les trajets de navires, les bouĂ©es, les tours, les stations d’échantillonnage, les rĂ©seaux de capteurs, les sites de vĂ©gĂ©tation, les fluviomĂštres et les observatoires) oĂč des donnĂ©es marines, terrestres ou atmosphĂ©riques sont prĂ©levĂ©es. Parmi les partenaires qui collaborent Ă  cette ressource, notons U.S. NSF, ACADIS, ADIwg, AOOS, a2dc, AON, ARMAP, BAID, CAFF, IASOA, INTERACT et d’autres encore. Bien que l’AOV se concentre sur les activitĂ©s amĂ©ricaines, il accepte l’échange d’information avec des groupes internationaux lorsqu’il existe des avantages mutuels. Les utilisateurs peuvent visualiser les donnĂ©es, naviguer dans le systĂšme, faire des sĂ©lections et des recherches, dessiner, imprimer et ainsi de suite. L’AOV fonctionne moyennant des principes d’interopĂ©rabilitĂ©, avec des mĂ©tadonnĂ©es ouvertes et des normes de service sur le Web afin que les organismes et les organisations puissent utiliser les outils et les services de l’AOV pour leurs propres fins. De cette façon, l’AOV sera en mesure de consolider et de complĂ©ter d’autres cyberressources Ă  la fois rĂ©parties et interopĂ©rables, en plus d’aider les planificateurs de la science, les bailleurs de fonds, les chercheurs, les spĂ©cialistes des donnĂ©es et d’autres encore Ă  Ă©valuer les statuts, Ă  repĂ©rer les dĂ©doublements, Ă  combler les Ă©carts, Ă  optimiser les plans d’échantillonnage, Ă  raffiner le rendement des rĂ©seaux, Ă  clarifier les consignes, Ă  accĂ©der aux donnĂ©es, Ă  coordonner la logistique, Ă  collaborer et ainsi de suite afin de rĂ©pondre aux objectifs d’observation de l’Arctique

    Polar Data Forum IV – An Ocean of Opportunities

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    This paper reports on the Hackathon Sessions organised at the Polar Data Forum IV (PDF IV) (20–24 September 2021), during which 351 participants from 50 different countries discussed collaboratively about the latest developments in polar data management. The 4th edition of the PDF hosted lively discussions on (i) best practices for polar data management, (ii) data policy, (ii) documenting data flows into aggregators, (iv) data interoperability, (v) polar federated search, (vi) semantics and vocabularies, (vii) Virtual Research Environments (VREs), and (viii) new polar technologies. This paper provides an overview of the organisational aspects of PDF IV and summarises the polar data objectives and outcomes by describing the conclusions drawn from the Hackathon Sessions

    Movements of marine fish and decapod crustaceans: Process, theory and application

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    Many marine species have a multi-phase ontogeny, with each phase usually associated with a spatially and temporally discrete set of movements. For many fish and decapod crustaceans that live inshore, a tri-phasic life cycle is widespread, involving: (1) the movement of planktonic eggs and larvae to nursery areas; (2) a range of routine shelter and foraging movements that maintain a home range; and (3) spawning migrations away from the home range to close the life cycle. Additional complexity is found in migrations that are not for the purpose of spawning and movements that result in a relocation of the home range of an individual that cannot be defined as an ontogenetic shift. Tracking and tagging studies confirm that life cycle movements occur across a wide range of spatial and temporal scales. This dynamic multi-scale complexity presents a significant problem in selecting appropriate scales for studying highly mobile marine animals. We address this problem by first comprehensively reviewing the movement patterns of fish and decapod crustaceans that use inshore areas and present a synthesis of life cycle strategies, together with five categories of movement. We then examine the scale-related limitations of traditional approaches to studies of animal-environment relationships. We demonstrate that studies of marine animals have rarely been undertaken at scales appropriate to the way animals use their environment and argue that future studies must incorporate animal movement into the design of sampling strategies. A major limitation of many studies is that they have focused on: (1) a single scale for animals that respond to their environment at multiple scales or (2) a single habitat type for animals that use multiple habitat types. We develop a hierarchical conceptual framework that deals with the problem of scale and environmental heterogeneity and we offer a new definition of 'habitat' from an organism-based perspective. To demonstrate that the conceptual framework can be applied, we explore the range of tools that are currently available for both measuring animal movement patterns and for mapping and quantifying marine environments at multiple scales. The application of a hierarchical approach, together with the coordinated integration of spatial technologies offers an unprecedented opportunity for researchers to tackle a range of animal-environment questions for highly mobile marine animals. Without scale-explicit information on animal movements many marine conservation and resource management strategies are less likely to achieve their primary objectives

    Use of alternative and complementary therapies in labor and delivery care: a cross-sectional study of midwives" training in Catalan hospitals accredited as centers for normal birth

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    Background: The use of complementary and alternative medicine (CAM) and complementary and alternative therapies (CAT) during pregnancy is increasing. Scientific evidence for CAM and CAT in the field of obstetrics mainly covers pain relief in labor. Midwives are responsible for labor and delivery care: hence, their knowledge of CAM and CAT is important. The aims of this study are to describe the professional profile of midwives who provide care for natural childbirth in Catalan hospitals accredited as centers for normal birth, to assess midwives" level of training in CAT and their use of these therapies, and to identify specific resources for CAT in labor wards. Methods: A descriptive, cross-sectional, quantitative method was used to assess the level of training and use of CAT by midwives working at 28 hospitals in Catalonia, Spain, accredited as public normal birth centers. Results: Just under a third of midwives (30.4%) trained in CAT after completion of basic training. They trained in an average of 5.97 therapies (SD 3.56). The number of CAT in which the midwives were trained correlated negatively with age (r = - 0.284; p < 0.001) and with their time working at the hospital in years (r = - 0.136; p = 0.036). Midwives trained in CAT considered that the following therapies were useful or very useful for pain relief during labor and delivery: relaxation techniques (64.3%), hydrotherapy (84.8%) and the application of compresses to the perineum (75.9%). The availability of resources for providing CAT during normal birth care varied widely from center to center. Conclusions: Age may influence attitudes towards training. It is important to increase the number of midwives trained in CAM for pain relief during childbirth, in order to promote the use of CAT and ensure efficiency and safety. CAT resources at accredited hospitals providing normal childbirth care should also be standardized

    The ACD Classification of Arctic Coasts

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    An important outcome of Arctic Coastal Dynamics I was the segmentation and characterization of the entire circum-Arctic coastline by regional experts which is presented in this dataset. This dataset contains data on coastal morphology, composition, dominant processes, ground ice, and environmental forcing parameters such as wind speed, storm counts, melt season, and wave energy. A listing of the variables included in the coastal classification can be found in Appendix A of the ACD II Science and Implementation Plan (2006). This information is available for over 800 segments, covering the coastline of all eight regional seas of the Arctic Ocean. The length of individual segments is variable (median length is 38 km), and depends on classification parameters and data availability. The segmentation format is scalable, allowing the adoption of future digital coastlines and the integration of additional data at higher spatial resolution. An assessment of the data quality for the more important quantitative variables has just been completed and the data will be publicly released on an internet map server (IMS). The goal of the IMS will be to allow individual users to prepare their own maps displaying the region and variables of interest. The ACD Classification was conceived as a broad enough framework to encompass existing classification schemes while capturing fundamental information for the assessment of climate change impacts and coastal processes. The implementation of the classification was done by so-called "regional experts", who, based on digital and paper products and personal knowledge provided information which was subsequently gathered into a circum-Arctic coastal database. The classification was primarily geomorphological in nature and considered: (1) the shape or form of the subaerial part of the coastal tract, (2) the marine processes acting upon the coast, (3) the shape or the form of the subaqueous part of the coastal tract and (4) the lithofacies of the materials constituting the coastal zone The beta version of the classification is made of 1331 segments each characterized by a series of geomorphological quantitative and qualitative variables. The classification is stored as an ISO 19115-compliant personal geodatabase and is therefore mappable in off-the-shelf Geographical Information Systems (GIS

    Cultural Socialization and Ethnic Pride Among Mexican-Origin Adolescents During the Transition to Middle School

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    The relation between cultural socialization and ethnic pride during the transition to middle school was examined for 674 5(th) grade students (50% boys; M(age) = 10.4 years) of Mexican origin. The theoretical model guiding the study proposes that parent-child relationship quality is a resource in the transmission of cultural values from parent to child and that parental warmth promotes the child's positive response to cultural socialization. Results showed that mother and father cultural socialization predicted youth ethnic pride, and that this relation was stronger when parents were high in warmth. The findings highlight the positive role parent cultural socialization may play in the development of adolescent ethnic pride. Furthermore, findings reveal the role of parent-child relationship quality in this process
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