25 research outputs found

    Book of Abstracts submitted to the IV Congress of Marine Sciences

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    The Canary Upwelling System (CUS), a major eastern boundary upwelling system, sustains large crossborder fisheries of small pelagic fish, which poses the question of stock connectivity. Studies suggest that ichthyoplankton transport from the northwest African coast to the Canary Islands (CI) is facilitated by coastal- upwelling associated filaments. Here we analyze connections between larval supply to the CI and sardine and anchovy populations that spawn over the continental shelf. For both species, ichthyoplankton observations (1) at the shelf and (2) near the island of Gran Canaria (GC) are used. Predictions of ichthyoplankton transport to GC are obtained from the Ichthyop Lagrangian transport model, which is forced by a high-resolution hydrodynamic model (ROMS) that reproduces the regional circulation. Results show that upwelling filaments play an important role in the transport of larvae to GC. However, (1) filaments are not the only mechanism, and (2) filament presence does not necessarily imply larval transport. Anchovy and sardine larval presence at GC appears to be independent of the respective adult spawning seasonality. Combining of observed and modeled data does not succeed in reproducing the observed larval patterns at GC. Various hypotheses are proposed to explain this discrepancy in larval transport to GC

    The role of neuronavigation in intracranial endoscopic procedures

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    In occlusive hydrocephalus, cysts and some ventricular tumours, neuroendoscopy has replaced shunt operations and microsurgery. There is an ongoing discussion if neuronavigation should routinely accompany neuroendoscopy or if its use should be limited to selected cases. In this prospective clinical series, the role of neuronavigation during intracranial endoscopic procedures was investigated. In 126 consecutive endoscopic procedures (endoscopic third ventriculostomy, ETV, n = 65; tumour biopsy/resection, n = 36; non-tumourous cyst fenestration, n = 23; abscess aspiration and hematoma removal, n = 1 each), performed in 121 patients, neuronavigation was made available. After operation and videotape review, the surgeon had to categorize the role of neuronavigation: not beneficial; beneficial, but not essential; essential. Overall, neuronavigation was of value in more than 50% of the operations, but its value depended on the type of the procedure. Neuronavigation was beneficial, but not essential in 16 ETVs (24.6%), 19 tumour biopsies/resections (52.7%) and 14 cyst fenestrations (60.9%). Neuronavigation was essential in 1 ETV (2%), 11 tumour biopsies/resections (30.6%) and 8 cyst fenestrations (34.8%). Neuronavigation was not needed/not used in 48 ETVs (73.9%), 6 endoscopic tumour operations (16.7%) and 1 cyst fenestration (4.3%). For ETV, neuronavigation mostly is not required. In the majority of the remaining endoscopic procedures, however, neuronavigation is at least beneficial. This finding suggests integrating neuronavigation into the operative routine in endoscopic tumour operations and cyst fenestrations

    Learning ecologies through a lens: Ontological, methodological and applicative issues. A systematic review of the literature

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    The concept of learning ecologies emerged in a context of educational change. While the “learning ecologies” construct has offered a broad semantic space for characterizing innovative ways of learning, it is also true that its potential to promote innovative educational interventions may have been hindered by this same broadness. Based on this assumption, in this paper the authors carried out a systematic review of the literature on learning ecologies with the aim of analysing: (1) the varying definitions given to the concept, including the ontological perspective underlying the phenomena studied; (2) the methodological approaches adopted in studying the phenomenon; and (3) the applications of the research on this topic. Throughout this analysis, the authors attempt to describe the criticalities of the existing research, as well as the potential areas of development that align well with the theoretical/ontological issues, methodological approaches and educational applications. The authors selected and analysed 85 articles, which they then classified in a set of 20 categories defined by them on a theoretical basis. Moreover, in order to triangulate the manual coding, a bibliometric map was created showing the co-citation activity of the 85 papers. The emerging picture showed significant variability in the ontological definitions and methodological approaches. In spite of this richness, few educational applications currently exist, particularly with regard to technology-enhanced learning developments. Most research is observational, devoted to describing hybrid (digital and on-site) learning activities that bridge the gap between the school and social spaces. Furthermore, many of the studies relate to the field of secondary education, with fewer studies exploring adult learning and higher education. The studies dealing with professional development relate mostly to teachers’ continuing education. The authors conclude that the concept of learning ecologies could be used to address further experimental and design-based research leading to research applications if there is proper alignment between the ontological, methodological and applicative dimensions. The main potential of this strategy lies in the possibility of supporting learners by raising their awareness of their own learning ecologies, thereby empowering them and encouraging them to engage in agentic practices. This empowerment could help maintain and build new and better learning opportunities, which every learning ecology can incorporate, amidst the chaotic abundance that characterizes the digital society

    EFFECTS OF CLIMATIC CONDITIONS ON CLIMBING PERFORMANCE IN A MOUNTAIN ULTRA-MARATHON RACE

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    PURPOSE: The purpose of this study was to investigate the influence of climatic conditions on performance in a ~50 km mountainous trail running race. Anecdotal evidence suggests that increased humidity in forested race courses is associated with increased heat stress and decreased performance in ultra-marathoners. We hypothesized that slower climb times would be associated with elevated ambient vapour pressure (VP) and temperature during an ultra-marathon course with heavy tree cover. The rationale follows from body heat loss and cooling being largely dependent on evaporation of eccrine sweat, which is directly proportional to the VP gradient between the ambient air and that on the skin surface. METHODS: Eight healthy males and one female volunteered for the study. Their mean height was 178.3±5.5 cm (mean±SD), weight 71.0±8.3 kg, Body Mass Index 22.4±2.1 ml/kg2, and age 49.7±8.2 years. The office of research ethics at SFU approved the study. Dry bulb (DBT) and wet bulb temperatures were assessed as well as relative humidity (RH) with an electronic humidity sensor. From these ambient VP was determined from a psychometric chart. Wind velocity was assessed with an anemometer. Globe temperature was determined using a Vernon globe thermometer. Remote Omega sensors were used to measure temperature, RH and dew points at three course locations. The GPS coordinates of measurement sites were determined using a handheld instrument. First order linear regression analysis was employed for the analyses and the P value was set at 0.05. RESULTS: Over the race duration there were progressive increases in DB temperature, RH and ambient VP. The mean DBT at the 3 maximum elevations in the race was 21.52±0.57°C and this was positively correlated to mean climb time of 72.26±9.76 min with an R2 = 0.92, p\u3c0.05. The mean RH of 55.39±1.39% was negatively correlated to mean climb time with R2 = 0.47, p\u3c0.05. The mean ambient vapour pressure of 10.73±0.28 mmHg, however, was positively correlated to mean climb time with R2 = 0.40, p\u3c0.10. CONCLUSION: In conclusion, these preliminary results support the hypothesis that increased temperature and ambient vapour pressure are associated with a decrease in performance during strenuous climbs during an ultramarathon on a tree covered course

    Feasibility study of aerocapture at mars with an innovative deployable heat shield

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    Performing orbital insertion around Mars using aerocapture instead of a propulsive orbit insertion maneuver allows the saving of resources and/or the increase of the payload mass fraction. Aerocapture has never been employed to date because of the high uncertainties in the parameters from which it depends, mainly related to atmospheric density modeling and navigation errors. The purpose of this work is to investigate the feasibility of aerocapture at Mars with an innovative deployable drag device, whose aperture can be modulated in flight, and to assess the effects of the main uncertainties on the success of the maneuver. This paper starts with the presentation of a parametric bidimensional analysis of the effectiveness of aerocapture, for which a wide range of uncertainty levels in the atmospheric density and the ballistic coefficient are considered. Then, an application to a real mission scenario is carried out, including the error of the targeting maneuver performed at the limit of the sphere of influence of the planet. The analyses show the strong influence of the uncertainties in the atmospheric density and the ballistic coefficient, which significantly narrow the solution space and limit its continuity. However, viable solutions for aerocapture can still be identified, even in the worst conditions

    Mirroring learning ecologies of outstanding teachers to integrate ICTs in the classroom

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    This paper presents an exploratory study to examine the practices of outstanding primary school teachers in their professional development for ICT integration in teaching and learning, as a means of understanding how their learning ecologies develop and function. Outstanding teachers in the context of this study are teachers who innovate pedagogically and who are influential in the community, having successfully developed their learning ecology. Using a qualitative approach, we explore the concept of learning ecologies as a driver for innovation in the professional development of teachers, using a carefully selected sample of nine outstanding teachers. Drawing from in-depth interviews, specific coding and NVIVO analysis, our results show that these teachers develop organized systems for activities, relationships and resource usage and production, which can be characterized as the components of their professional learning ecology, to continuously keep up to date. We also identified some characteristics of teachers that perform outstandingly and factors that potentially facilitate or hinder their learning ecology development. Further research in the field will enable an improved understanding of the professional learning ecologies of school teachers and support future interventions and recommendations for professional development through the cultivation of emerging professional learning ecologies

    Steep Shelf Stabilization of the Coastal Bransfield Current: Linear Stability Analysis

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    International audienceIn situ measurements obtained during the 2010 COUPLING cruise were analyzed in order to fully characterize the velocity structure of the coastal Bransfield Current. An idealized two-layer shallow-water model was used to investigate the various instability processes of the realistic current along the coastal shelf. Particularly studied is how the topographic parameter To (ratio between the shelf slope and the isopycnal slope of the surface current) impacts the growth and the wavelength of the unstable perturbations. For small bottom slopes, when the evolution of the coastal current is controlled by the baroclinic instability, the increase of the topographic parameter To yields a selection of smaller unstable wavelengths. The growth rates increase with small values of To. For larger values of To (To greater than or similar to 10, which is relevant for the coastal Bransfield Current), the baroclinic instability is strongly dampened and the horizontal shear instability becomes the dominant one. In this steep shelf regime, the unstable growth rate and the wavelength selection of the baroclinic coastal current remains almost constant and weakly affected by the amplitude of the bottom velocity or the exact value of the shelf slope. Hence, the linear stability analysis of an idealized Bransfield Current predicts a typical growth time of 7.7 days and an alongshore scale of 47 km all along the South Shetland Island shelf. The fact that these large growth times are identical to the typical transit time of water parcels along the shelf may explain why the current does not exhibit any unstable meanders

    Biofluids in Orofacial Pain: Review

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    Orofacial pain is a dental specialty that focuses on diagnosing and treating long-term, complicated facial discomfort caused by oromotor disorders. This pain is similar to pain elsewhere in the body and is generally caused by tissue damages. The pathogenesis of orofacialpain might be caused by orofacial structures illness, musculoskeletal system disorders, peripheral or central nervous system disorders, systemic diseases, psychological problems, or the result of inadequate sleep. One method to diagnose is evaluating the molecular and microbial cues of biological fluids, which may indicate the occurrence or progression of the disease. This article provides an overview of these biofluids and biomarkers and their role in progression of orofacial diseases
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