7,729 research outputs found

    The first report of South American edrioasteroids and the paleoecology and ontogeny of rhenopyrgid echinoderms

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    A new species of rhenopyrgid edrioasteroid Rhenopyrgus piojoensis sp. nov. is described form the Silurian (Lower Lud− low) Los Espejos Formation in the Precordillera of Argentina. This species is the first reported edrioasteroid from South America. Rhenopyrgids are widely distributed in Ordovician through Devonian deposits of most continents. Numerous juvenile specimens show that the general bodyplan is organized early in ontogeny and that the pedenculate zone lengthens with age. Phylogenetic analysis shows that rhenopyrgids are more closely related to edrioasterid edrioasteroids such as edrioblastoids and cyathocystids than to pyrgocystid isorophids.Fil: Sumrall, Colin D.. University of Tennessee; Estados UnidosFil: Heredia, Susana Emma. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rodríguez, Cecilia María. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mestre García, Ana Isabel. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Effect of debris size on the tribological performance of thermally sprayed coatings

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    This research aims to assess the effect of the debris particle size on the tribological performance and lubrication regime parameters of a Ni-based alloy coating. This is a key industrial problem, and its resolution can contribute to better machine endurance and proper maintenance. The debris particles are simulated by hard Al2O3 particles of size ranging from nanometers to 45 μm and dispersed in an oil lubricant. The coating studied is NiCrBSi deposited by flame spraying technique followed by the Surface Flame Melting (SFM) process. The counterpart disk sample was fabricated from quenched and tempered F-5220 steel (in line with A681(O1) ASTM). This pair was tested under linear sliding contact. Our results show that the addition of alumina particles contributes to a significant increase in wear, particularly for the largest particles (micrometric size). In the case of micrometric particles, it is possible to observe the formation of higher surface roughness, numerous microgrooves, and plastic flow of NiCrBSi coating perpendicular to the sliding direction, resulting in higher loss of volume. It was found that the actual surface roughness (obtained as a function of the debris particle size) allows better identification and prediction of the lubrication regime for wear processes instead of the traditional approach that uses the initial surface roughness as a parameter

    Strategies Used by Military Spouse Small Businesses During a Military Relocation

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    There are over 615,000 women military spouses and 1,786 known military spouse business owners who relocate every 2 to 3 years to follow their active duty spouse. The research problem addressed was the lack of strategies military spouse small business owners used to sustain their business during a mandatory military relocation. The purpose of this multiple case study was to explore the strategies 5 women military spouse small business owners, located at military installations in the Midlands and Pee Dee regions of South Carolina, used to sustain their businesses during a relocation. The sampling method used was census sampling. The systems theory was the conceptual framework of this research supported by sustainability, strategic management, and event system theories. In-depth semistructured interviews and archival documentations were the chosen methods of data collection. A CADQAS software was used to organize the data and content analysis method was to analyze the data gathered from the interviews and documents. The emergent themes were small businesses, work-life balance, business finance, barrier to business ownership, initiatives to support military spouses, and personal finances quality of life

    Facomatosis. Estado actual

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    Se describen las facomatosis más frecuentes y principales dividiéndolas en dos grandes grupos polares siguiendo la tradicional e inveterada clasificación confeccionada por Brouwer y Van der Hoeve, es decir: neuroectodérmicas porque afectan fundamentalmente al sistema nervioso y las de origen mesodérmico que atacan preferencialmente en primera línea, al aparato circulatorio. Tras realizar un sucinto esbozo histórico, rememorar la estrecha vinculación existente entre la Oftalmología y demás especialidades médicas, se describe con minuciosidad las enfermedades de Von Recklinghausen o neurofibromatosis múltiple y la esclerosis cerebral tuberosa o enfermedad de Bourneville como máximas representantes del primer grupo y las de Sturge-Weber- Krabbe también denominada angiomatosis trigémino cerebral o meníngeo-cutánea o encéfalo-trigeminal y la enfermedad de Von Hippel-Lindau conocida igualmente por angioglioblastomatosis retino-cerebelosa como más habituales dentro de las mesodérmicas se incide en los medios diagnóstico, complejos cuadros clínicos multiformes y diversos tratamientos. De momento hasta hoy, las mesodérmicas revisten mejor pronóstico desde el punto de vista ocular se termina tras sintetizar los últimos avances en materia de Bioquímica, Biología Molecular y Celular haciendo hincapié en la posible génesis autoinmunitaria de todas las Facomatosis y en la futura prometedora terapia de las mismas, recurriendo al empleo de Células Madres.The most common Phakomatoses are divided into two groups following the long standing classification made by Brower and Van der Hoeve. The first group is of neuroectodermal origin affecting mainly the nervous system and the second is of mesodermal origin attacking preferentially the circulatory apparatus. After a succinct historical outline and review of the close link demonstrated between Ophthalmology and others medical specialties, the author puts forth a detailed description of Von Recklinghausen´s disease (multiple neurofibromatosis) and Tuberous Sclerosis (Bourneville disease) as primary representatives of the first group. In the second group we have Sturge-Weber- Krabbe, also called cerebro-trigeminal angiomatosis or meningo-cutaneus or encephalo-trigeminal and Von Hippel-Lindau´s disease also known as retino-cerebellar angioglioblastomatosis. The several diagnostic tools and different treatments of these complex pathologies are explained. All the entities of mesodermal origin have better ocular prognoses. After describing the latest developments in Biochemistry, Molecular and Cellular Biology and pointing out the possible autoimmune genesis of Phakomatoses, there is optimism for future therapies employing stem cells

    Taking Stock of Common Core Math Implementation: Supporting Teachers to Shift Instruction: Insights from the Math in Common 2015 Baseline Survey of Teachers and Administrators

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    In spring 2015, WestEd administered surveys to understand the perspectives on Common Core State Standards-Mathematics (CCSS-M) implementation of teachers and administrators in eight California school districts participating in the Math in Common (MiC) initiative. From this survey effort, we were able to learn from over 1,000 respondents about some of the initial successes and challenges facing California educators attempting to put in place and support new -- and what some consider revolutionary -- ideas in U.S. mathematics education

    Structure of the Southern Patagonian Andes at 49ºS, Argentina

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    This paper describes Late Paleozoic Gondwanan and Late Cretaceous to Early Cenozoic Andean structures in the Southern Patagonian Andes and an associated Extra-Andean region between lakes San Martín and Viedma. The study area encompasses a 200-km-long W-E section between the Patagonian icefield and the 72ºW longitude meridian, in Argentine Patagonia. The oldest structures are of Late Paleozoic age and developed through at least two deformation phases during the Gondwanan Orogeny. The first deformation phase (Dg1) includes isoclinal and N-overturned WNW trending folds and associated thrusts, including duplexes. The second deformation phase includes NNE trending open folds (Dg2). Deformation occurred in non-metamorphic to very low-grade metamorphic conditions. A spaced rough cleavage is found near the first phase fold hinges. The Eocene and Miocene Andean structural compression resulted in a N-S oriented fold and thrust belt. This belt is comprised of three morphostructural zones from W to E, with distinctive topographic altitudes and structural styles: Andean; Sub-Andean; and Extra-Andean zones. The first corresponds to the inner fold and thrust belt, while the last two are part of the outer fold and thrust belt. The Andean zone (3400–2000m above sea level) is characterized by N-S to NNE trending, E-vergent, Cenozoic reverse faults and associated minor thrusts. The northern part of the Sub- Andean zone (2000–1500m above sea level) consists of W-vergent reverse faults and some NNE open folds. The southern part of the Andean zone includes tight folds with box and kink geometries, related to thrusts at deeper levels. In the Extra-Andean zone, with maximum heights of 1500m, the deformation is less intense, and gentle folds deform the Upper Cretaceous sediments. An inherited Jurassic N-S extensional fault system imposed a strong control on this morphostructural zonation. Also the variation of the Austral Basin sedimentary thickness in the N-S direction seems to have influenced the structural styles of the outer fold and thrust belt. Those differences in sedimentary thickness may be related to S-dipping transfer zones associated to W-E Jurassic extension. In turn, the transfer zones may have been controlled by the N-vergent WNW, Dg1, Gondwanan structural fabric

    Driving the blue fleet: Temporal variability and drivers behind bluebottle (Physalia physalis) beachings off Sydney, Australia

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    Physalia physalis, the bluebottle in Australia, are colonial siphonophores that live at the surface of the ocean, mainly in tropical and subtropical waters. P. physalis are sometimes present in large swarms, and with tentacles capable of intense stings, they can negatively impact public health and commercial fisheries. P. physalis, which does not swim, is advected by ocean currents and winds acting on its gas-filled sail. While previous studies have attempted to model the drift of P. physalis, little is known about its sources, distribution, and the timing of its arrival to shore. In this study, we present a dataset with four years of daily P. physalis beachings and stings reports at three locations off Sydney's coast in Australia. We investigate the spatial and temporal variability of P. physalis presence (beachings and stings) in relation to different environmental parameters. This dataset shows a clear seasonal pattern where more P. physalis beachings occur in the Austral summer and less in winter. Cold ocean temperatures do not hinder the presence of P. physalis and the temperature seasonal cycle and that observed in P. physalis presence/absence time-series are out of phase by 3-4 months. We identify wind direction as the major driver of the temporal variability of P. physalis arrival to the shore, both at daily and seasonal time-scales. The differences observed between sites of the occurrence of beaching events is consistent with the geomorphology of the coastline which influences the frequency and direction of favorable wind conditions. We also show that rip currents, a physical mechanism occurring at the scale of the beach, can be a predictor of beaching events. This study is a first step towards understanding the dynamics of P. physalis transport and ultimately being able to predict its arrival to the coast and mitigating the number of people who experience painful stings and require medical help

    Additional Physical Interventions to Conventional Physical Therapy in Parkinson’s Disease: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

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    Parkinson's disease (PD) represents the second most common neurodegenerative disease. Currently, conventional physical therapy is complemented by additional physical interventions with recreational components, improving different motor conditions in people with PD. This review aims to evaluate the effectiveness of additional physical interventions to conventional physical therapy in Parkinson's disease. A systematic review and meta-analysis of randomized controlled trials were performed. The literature search was conducted in PubMed, Physiotherapy Evidence Database (PEDro), Scopus, SciELO and Web of Science. The PEDro scale was used to evaluate the methodological quality of the studies. A total of 11 randomized controlled trials were included in this review. Five of them contributed information to the meta-analysis. The statistical analysis showed favorable results for dance-based therapy in motor balance: (Timed Up and Go: standardized mean difference (SMD) = −1.16; 95% Confidence Interval (CI):(−2.30 to −0.03); Berg Balance Scale: SMD = 4.05; 95%CI:(1.34 to 6.75)). Aquatic interventions showed favorable results in balance confidence (Activities-Specific Balance Confidence: SMD=10.10; 95%CI:(2.27 to 17.93)). The results obtained in this review highlight the potential benefit of dance-based therapy in functional balance for people with Parkinson's disease, recommending its incorporation in clinical practice. Nonetheless, many aspects require clarification through further research and high-quality studies on this subject

    A probabilistic patient scheduling model for reducing the number of no-shows

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    No-shows in medical centres cause under-utilisation of resources and increase waiting times in specialty health care services. Although this problem has been addressed in literature, behavioural issues associated with the patient's socio-demographic characteristics and diagnosis have not been widely studied. In this article, we propose a model that includes such behavioural issues in order to reduce impact of no-shows in medical services. The objective is maximising the health centre's expected revenue by using show-up probabilities estimated for each combination of patient and appointment slot. Additionally, the model considers the requirements imposed by both the health centre's management and the health authorities. An extension of the model allows overbooking in some appointment slots. Experimental results show that the proposed model can reduce the waiting list length by 13%, and to attain an increase of about 5% in revenue, when comparing to a model that assigns patients to the first available slot
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