278 research outputs found

    Investigation into the steering ability problems of compact hovercrafts

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    The present paper investigates the requirements and the turning ability problems of the hovercrafts characterized by compact dimensions (with small width, powerful engine and big propellers). These vehicles require a very accurate control system, to combine the command of turning or trim with the possibility of reversing the thrust. In this article we briefly describe compact hovercrafts and focus on the various systems projected to improve their turning ability. We give an account of the steps which led to achieve our technical solutions and show the various systems of passive control surfaces adopted: to verify the different assessed implementations, several on-field tests have been performed on two vehicles, the Hover4 and the Multipurpose Air Cushion Platform (MACP). Finally we illustrate the ultimate chosen version of the system, in particular we outline the positive effects of the adoption of an unusual axis of rotation used to solve the problems created by the vertical rudders, whose centre is higher than the barycentre of the vehicle

    Medication management ability in older patients: Time for a reappraisal

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    Background. Adhering to drug regimens is a complex and multidimensional task. Elderly patients usually take an average of seven drugs but most fail to adhere to the prescribed regimen. Several performance-based instruments have been developed to assess a patient\u2019s capacity to manage drugs but with inconsistent results. Aims. The aim of the study was to assess the prevalence of impaired medical management capacity in a sample of the oldest old hospitalized elderly patients and the main clinical factors associated with potential unintentional non-adherence. Methods. Forty-six consecutive patients were enrolled in the geriatric transitional care unit of Ospedale Policlinico San Martino, Genoa, Italy. All patients received an abbreviated comprehensive geriatric assessment and a hand grip assessment for sarcopenia. Patients\u2019 medication management ability was assessed by administering the DRUGS tool 48-74 hours before hospital discharge. Results. The results showed a negative correlation between age and total medication management score. A positive correlation was detected between functional status, cognitive status, and medication management score. Hand grip strength < 9 kg correlated with a significant worsening of medical management capacity. In contrast, multiple morbidities and the mean number of drugs were not associated with the medical management score. Conclusions. This preliminary study indicated that drug management capacity mainly relies on frailty markers, such as functional status, sarcopenia, and cognitive performance. Further studies are warranted to identify a subset of medical parameters that can accurately predict impaired medical management ability early, particularly for highly vulnerable elderly patients

    Monitoring of sea-ice-atmosphere interface in the proximity of arctic tidewater glaciers: The contribution of marine robotics

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    The Svalbard archipelago, with its partially closed waters influenced by both oceanic conditions and large tidal glaciers, represents a prime target for understanding the effects of ongoing climate change on glaciers, oceans, and ecosystems. An understanding of the role played by tidewater glaciers in marine primary production is still affected by a lack of data from close proximity to glacier fronts, to which, for safety reasons, manned surface vessels cannot get too close. In this context, autonomous marine vehicles can play a key role in collecting high quality data in dangerous interface areas. In particular, the contribution given by light, portable, and modular marine robots is discussed in this paper. The state-of-the-art of technology and of operating procedures is established on the basis of the experience gained in campaigns carried out by Italian National Research Council (CNR) robotic researchers in Ny-Alesund, Svalbard Islands, in 2015, 2017, and 2018 respectively. The aim was to demonstrate the capability of an Unmanned Semi-Submersible Vehicle (USSV): (i) To collect water samples in contact with the front of a tidewater glacier; (ii) to work in cooperation with Unmanned Aerial Vehicles (UAV) for sea surface and air column characterisation in the proximity of the fronts of the glaciers; and (iii) to perform, when equipped with suitable tools and instruments, repetitive sampling of water surface as well as profiling the parameters of the water and air column close to the fronts of the tidewater glaciers. The article also reports the issues encountered in navigating in the middle of bergy bits and growlers as well as the problems faced in using some sensors at high latitudes

    Modelo didáctico de profesores de enseñanza media de química : análisis de casos en el desarrollo del tema disoluciones (Santa Fe – Argentina)

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    La presente investigación se realizó en tres aulas de Química de Enseñanza Media (Argentina) durante el año 2008, en el marco del proyecto AECI/7510/07 entre las universidades del Litoral (Argentina) y de Santiago de Compostela (España). El propósito fue caracterizar los modelos didácticos que se ponen de manifiesto al desarrollar los docentes, una propuesta de tipo constructivista de secuencias de enseñanza para el tema Disoluciones. Con los aportes del análisis de opinión de las actividades (pre y post) realizadas por los docentes y la observación directa de las clases, se infiere que los profesores desarrollan sus clases en forma tradicional -probablemente la metodología propuesta no ha sido asimilada debido al tipo de instrucción al que están habituados el profesorado y el alumnado- aunque se observan intentos de aproximarse a modelos más constructivistas

    Problemas cuantitativos y comprensión de conceptos

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    Los docentes de química a nivel universitario usamos «problemas», habitualmente de tipo cuantitativo, para enseñar y para evaluar. En este trabajo ponemos en duda de que lo hagamos en forma eficaz. Se muestra, a partir de pruebas diagnósticas de pares de problemas (uno cuantitativo y otro cualitativo similar), que muchos estudiantes pueden resolver los problemas cuantitativos sin una adecuada comprensión conceptual.Chemistry professors at university level make use of «problems», usually of a quantitative type, to teach and evaluate. In this article we question the fact of whether they do it in an efficient way. From diagnostic test of pairs of problems (a quantitative and a similar qualitative one) it is shown that many students can solve quantitative problems without an appropriate conceptual comprehension

    Behavioral disturbances in dementia and beyond: Time for a new conceptual frame?

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    Alzheimer\u2019s disease and vascular dementia are estimated to be the most common causes of dementia, although mixed dementia could represent the most prevalent form of dementia in older adults aged more than 80 years. Behavioral disturbances are common in the natural history of dementia. However, so far, there is a paucity of studies that investigated the causal association between behavioral psychological symptoms of dementia and dementia sub-types, due to the high heterogeneity of methodology, study design and type of clinical assessment. To understand the scant evidence on such a relevant clinical issue, it could be hypothesized that a new shifting paradigm could result in a better identification of the relationship between behavioral disturbances and dementia. This narrative review provides an update of evidence on the behavioral patterns associated with different dementia sub-types and offers a potential future perspective as common ground for the development of new translational studies in the field of behavioral disturbances in dementia and the appropriateness of psychoactive treatments

    Resistin: A reappraisal

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    Abstract From a biological point of view, aging can be considered a progressive inability of an organism to react to stress, maintain homeostasis, and survive unfavourable changes during post-maturational life. The expression of several adipokines changes during aging and for some changes, a role in the onset of chronic disease and frailty has been proposed. Among adipokines, resistin was shown in recent studies to play a key role in aging. Resistin is a small secreted protein that regulates glucose metabolism in mammalians. High resistin levels induce insulin resistance and exert proinflammatory effects. Consistently, resistin has been shown to play a pivotal role in various metabolic, inflammatory, and autoimmune diseases. Herein, the role of resistin as a molecular link between aging and age-related conditions was reviewed and the clinical implications of this knowledge discussed

    Design and construction of a modular pump-jet thruster for autonomous surface vehicle operations in extremely shallow water

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    open5noThis paper describes a customized thruster for Autonomous Surface Vehicles (ASV). The thruster is a Pump-Jet Module (PJM), which has been expressly designed, modeled, constructed, and tested for small-/medium-sized ASVs that perform environmental monitoring in extremely shallow waters such as wetlands (rivers, lakes, swamps, marshes), where water depth is only a few centimeters. The PJM is a fully-electric propulsion unit with a 360-degree continuous steering capability. Its main advantage is that the unit is flush with the flat bottom of the vehicle. This makes the PJM suitable for operation in extremely shallow waters because the risk of damaging the thrusting unit in case of grounding is very limited. The PJM was produced using innovative materials, and the hydraulic components were all constructed using a 3D printer.openOdetti A.; Altosole M.; Bruzzone G.; Caccia M.; Viviani M.Odetti, Angelo; Altosole, M.; Bruzzone, G.; Caccia, M.; Viviani, M

    IgG4 related disease in elderly: A case report

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    IgG4-related systemic disease (IgG4-RSD) is an emerging autoimmune disorder that may affect several organs, with signs of organ fibrosis, storiform masses for hystopathological plasmacellular infiltration and plasmatic elevation of IgG4. This clinical condition frequently occurs in the sixth decade and may be considered an autoimmunity of the elderly; the disease may have a smouldering course with frequent misdiagnosis for the co-occurrence of comorbidity and clinical complexity. The present case report describes the clinical case of an 81 years old woman admitted to the geriatric ward for remittent fever and functional decline. The past clinical history reported an isolated CT scan suggestive of retroperitoneal fibrosis of unknown origin with and a drug regimen that included chronic corticosteroids (prednisone 5 mg oad). The in hospital diagnostic workout demonstrated the presence of a thoracic aneurysm. Several possible diagnoses among inflammatory, autoimmune (connective tissue disease, vasculitis, sarcoidosis, amyloidosis), infectious (mycotic) or neoplastic conditions were ruled out, as well as any drug association with higher risk of retroperitoneal fibrosis. Thus, the clinical hypothesis of an IgG4 chronic periaortitis was formulated due to the co-occurrence of all the three major components: the presence of a retroperitoneal fibrosis, IgG4 related abdominal aortitis and peryaneurysmal fibrosis. Patient\u2019s comorbidity did not allow performing the histological analysis. The present clinical case is original and adds knowledge to the 76 cases of thoracic aortitis due to IgG4 systemic disease out of the 3482 cases of disease reported so far. Further clinical investigation is needed to provide a homogeneous diagnostic workout for tailored early therapeutic intervention on the single geriatric patient. Moreover, a growing awareness of the disease is needed, especially in geriatrics, to providing a better standard of care and to improving the disease clinical knowledge and managemen

    New cost-effective technologies applied to the study of the glacier melting influence on physical and biological processes in Kongsfjorden area (Svalbard)

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    The Arctic region is greatly affected by climate change, with evident alterations in both physical and biological processes: temperatures are changing at a rate that is twice the global average and phytoplankton productivity is directly affected by ice melting. Continuous monitoring of this ecosystem is fundamental to gain greater understanding of the impact of changes on the natural environment, but the Global Ocean Observing System only provides partial coverage in these extreme areas, which are particularly difficult to reach. Technological progress in oceanographic measurement capabilities is indispensable for the implementation of marine observatories, especially in these remote regions. In recent years, autonomous systems and cost-effective technologies have proved to be valuable for increasing spatial and temporal coverage of data. This is the case with the innovative ArLoC (Arctic Low-Cost) probe, which was designed and developed for easy integration into various types of platforms, enabling continuous measurement of temperature, pressure and fluorescence of chlorophyll a. This work reports on the results of two scientific campaigns carried out in Kongsfjorden (Svalbard Islands) in 2018 in the framework of the UVASS (Unmanned Vehicles for Autonomous Sensing and Sampling) research project. The ArLoC probe was integrated onboard the PROTEUS (Portable RObotic TEchnology for Unmanned Surveys) unmanned semi-submersible vehicle and this allowed us to collect important data in the stretches of sea near tidewater glacier fronts. The acquired data showed several significant effects of glacier melting such as: high temperature and salinity gradients, which cause considerable variations in water mass stratification, and an increase in turbidity and the chlorophyll a concentration, which directly affects primary productivity and the trophic chain. During the surveys, ArLoC proved to be an easy-to-integrate, very reliable instrument, which permitted high spatial resolution investigation of ecological processes during glacier melting as never studied before
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