271 research outputs found
Null-Space Minimization of Center of Gravity Displacementof a Redundant Aerial Manipulator
Displacements of the base during trajectory tracking are a common issue in the control of aerial manipulators. These are caused by reaction torques transferred to the base due to the manipulator motion and, in particular, to the motion of its center of gravity. We present a novel approach to reduce base displacements of a kinematically redundant aerial manipulator by using null-space projection in the inverse kinematic control. A secondary objective function minimizes the horizontal displacement of the manipulator center of gravity. We test this algorithm on different trajectories for both three and four degrees of freedom (DOF) manipulators in a simulation environment. The results comparing our algorithm with inverse kinematic control without the null-space projection show up to an 80% reduction in the end-effector position error and an average of about 56% reduction in maximum base displacement. The simulation implementation also runs faster than in real-time in our code implementation. We provide a workspace analysis based on multiple stopping criteria such as excessive base displacement, joint velocities and end-effector position error for the 3 and 4 DOF manipulators. As expected, the 4 DOF manipulator has a larger workspace
[Deprivation indices in small-area studies of environment and health in Italy].
The use of deprivation indices in small-area studies of environment and health is described, with particular reference to the Italian context. Deprivation indices can represent a proxy for individual deprivation and/or contextual deprivation. In Italy, deprivation indices have been constructed using Census variables. They are applied at census tract level in studies with a local basis; in national based studies, they can be used at municipality level. In SENTIERI Project (Mortality study of residents in Italian polluted sites) an ad hoc deprivation index at municipal level was used (DI SENTIERI). Its strength and weaknesses are discussed. In addition, suggestions about the use of socioeconomic indices in small area studies of environment
and health are given
Lactancia materna y hospital amigo del niño: una necesidad en la provincia de Corrientes
La Lactancia Materna (LM) es la mejor forma de alimentar y criar a un niño, no obstante su práctica se ha reducido paulatinamente. La Organización Mundial de la Salud (OMS) junto a UNICEF ha propuesto la “Iniciativa Hospital Amigo” (IHAN), con objetivos tendientes a restablecer y mejorar dicha práctica. Objetivos: Determinar las características socio-demográficas de las madres que asisten a un hospital de referencia de la Provincia de Corrientes; Identificar la influencia del nivel de instrucción materno con la posibilidad de mantener la LM exclusiva; y Evaluar la necesidad de la IHAN en nuestra Provincia. Materiales y Métodos: Se realizó estudio observacional descriptivo de corte transversal, a través de encuestas a 146 madres de la Maternidad del Hospital “Dr. José R. Vidal” en el período de Agosto a Diciembre del 2010. Resultados: El 79,5% estaba entre los 15 y 30 años; 53,4% se encontraban separadas o en concubinato, el 52,7% tenía un nivel de instrucción moderado; 97,9% consideraba importante amamantar, el 78,1% daría pecho exclusivo; 45,2% daría LM hasta el año; el 81,5% no trabaja fuera del hogar; 40,4% recibió información del equipo de salud; el 89% asistiría a un centro de apoyo de lactancia. Discusión: El IHAN, es una necesidad en nuestra región; lo que posibilitaría que el deseo expresado por las madres de amamantar más allá de los 6 meses y de contar con apoyo asistencial, sea posible.Introduction: Breastfeeding (BF) is the best way to feed and raise a child, however the practice has declined gradually. The World Health Organization (WHO) together with UNICEF has proposed the "Baby Friendly Hospital Initiative" (BFHI), with objectives aimed at restoring and improving the practice. Objectives: To determine the sociodemographic characteristics of mothers attending a referral hospital in the province of Corrientes, Identify the influence of mother's education level with the ability to maintain exclusive BF, and Evaluate the need for the BFHI in our province. Materials and Methods: Descriptive study of cross-section through surveys of 146 mothers in the Maternity Hospital "Dr. José R. Vidal" in the period from August to December 2010. Results: 79.5% were between 15 and 30 years, 53.4% were separated or cohabiting, 52.7% had a moderate level of education, 97.9% considered it important to breastfeed, 78.1% would exclusively breastfed, 45.2% would give for a year BF, 81.5% do not work outside the home, 40.4% received information from the health team, 89% would attend a breastfeeding support center. Discussion: The BFHI is a necessity in our region, that would allow the desire of mothers to breastfeed beyond 6 months and to have care support.Fil: Niello, Esteban N.. Universidad Nacional del Nordeste; ArgentinaFil: Palma Pérez, Ricardo D.. Universidad Nacional del Nordeste; ArgentinaFil: Pasetto, Raúl I.. Universidad Nacional del Nordeste; ArgentinaFil: Horna, Maria Eugenia. Universidad Nacional del Nordeste. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Hidalgo, Susana. Universidad Nacional del Nordeste; Argentin
Blocking entry of hepatitis B and D viruses to hepatocytes as a novel immunotherapy for treating chronic infections
Background. Chronic hepatitis B and D virus (HBV/HDV) infections can cause cancer. Current HBV therapy using nucleoside analogues (NAs) is life-long and reduces but does not eliminate the risk of cancer. A hallmark of chronic hepatitis B is a dysfunctional HBV-specific T-cell response. We therefore designed an immunotherapy driven by naive healthy T cells specific for the HDV antigen (HDAg) to bypass the need for HBV-specific T cells in order to prime PreS1-specific T cells and PreS1 antibodies blocking HBV entry.
Methods. Ten combinations of PreS1 and/or HDAg sequences were evaluated for induction of PreS1 antibodies and HBV- and HDV-specific T cells in vitro and in vivo. Neutralization of HBV by PreS1-specific murine and rabbit antibodies was evaluated in cell culture, and rabbit anti-PreS1 were tested for neutralization of HBV in mice repopulated with human hepatocytes.
Results. The best vaccine candidate induced T cells to PreS1 and HDAg, and PreS1 antibodies blocking HBV entry in vitro. Importantly, adoptive transfer of PreS1 antibodies prevented, or modulated, HBV infection after a subsequent challenge in humanized mice.
Conclusions. We here describe a novel immunotherapy for chronic HBV/HDV that targets viral entry to complement NAs and coming therapies inhibiting viral maturation
Investigation of the New Local Group Galaxy VV 124
We present the results of our stellar photometry and spectroscopy for the new
Local Group galaxy VV 124 (UGC 4879) obtained with the 6-m BTA telescope. The
presence of a few bright supergiants in the galaxy indicates that the current
star formation process is weak. The apparent distribution of stars with
different ages in VV 124 does not differ from the analogous distributions of
stars in irregular galaxies, but the ratio of the numbers of young and old
stars indicates that VV 124 belongs to the rare Irr/Sph type of galaxies. The
old stars (red giants) form the most extended structure, a thick disk with an
exponential decrease in the star number density to the edge. Definitely, the
young population unresolvable in images makes a great contribution to the
background emission from the central galactic regions. The presence of young
stars is also confirmed by the [O III] emission line visible in the spectra
that belongs to extensive diffuse galactic regions. The mean radial velocity of
several components (two bright supergiants, the unresolvable stellar
population, and the diffuse gas) is v_h = -70+/-15 km/s and the velocity with
which VV 124 falls into the Local Group is v_LG = -12+/-15 km/s. We confirm the
distance to the galaxy D = 1.1+/-0.1 Mpc and the metallicity of red giants
([Fe/H] = -1.37) found by Kopylov et al. (2008).VV 124 is located on the
periphery of the Local Group approximately at the same distance from M 31 and
our Galaxy and is isolated from other galaxies. The galaxy LeoA nearest to it
is 0.5 Mpc away.Comment: 10 pages, 8 figures. Accepted for publication in Astronomy Letters
(2010, Vol. 36, No. 5, pp. 309-318
RNS60 exerts therapeutic effects in the SOD1 ALS mouse model through protective glia and peripheral nerve rescue
Background: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease that affects the motor neuromuscular system leading to complete paralysis and premature death. The multifactorial nature of ALS that involves both cell-autonomous and non-cell-autonomous processes contributes to the lack of effective therapies, usually targeted to a single pathogenic mechanism. RNS60, an experimental drug containing oxygenated nanobubbles generated by modified Taylor-Couette-Poiseuille flow with elevated oxygen pressure, has shown anti-inflammatory and neuroprotective properties in different experimental paradigms. Since RNS60 interferes with multiple cellular mechanisms known to be involved in ALS pathology, we evaluated its effect in in vitro and in vivo models of ALS. Methods: Co-cultures of primary microglia/spinal neurons exposed to LPS and astrocytes/spinal neurons from SOD1 G93A mice were used to examine the effect of RNS60 or normal saline (NS) on the selective motor neuron degeneration. Transgenic SOD1 G93A mice were treated with RNS60 or NS (300\u3bcl/mouse intraperitoneally every other day) starting at the disease onset and examined for disease progression as well as pathological and biochemical alterations. Results: RNS60 protected motor neurons in in vitro paradigms and slowed the disease progression of C57BL/6-SOD1 G93A mice through a significant protection of spinal motor neurons and neuromuscular junctions. This was mediated by the (i) activation of an antioxidant response and generation of an anti-inflammatory environment in the spinal cord; (ii) activation of the PI3K-Akt pro-survival pathway in the spinal cord and sciatic nerves; (iii) reduced demyelination of the sciatic nerves; and (iv) elevation of peripheral CD4+/Foxp3+ T regulatory cell numbers. RNS60 did not show the same effects in 129Sv-SOD1 G93A mice, which are unable to activate a protective immune response. Conclusion: RNS60 demonstrated significant therapeutic efficacy in C57BL/6-SOD1 G93A mice by virtue of its effects on multiple disease mechanisms in motor neurons, glial cells, and peripheral immune cells. These findings, together with the excellent clinical safety profile, make RNS60 a promising candidate for ALS therapy and support further studies to unravel its molecular mechanism of action. In addition, the differences in efficacy of RNS60 in SOD1 G93A mice of different strains may be relevant for identifying potential markers to predict efficacy in clinical trials
Integration of satellite remote sensing data in ecosystem modelling at local scales: Practices and trends
1. Spatiotemporal ecological modelling of terrestrial ecosystems relies on climatological and biophysical Earth observations. Due to their increasing availability, global coverage, frequent acquisition and high spatial resolution, satellite remote sensing (SRS) products are frequently integrated to in situ data in the development of ecosystem models (EMs) quantifying the interaction among the vegetation component and the hydrological, energy and nutrient cycles. This review highlights the main advances achieved in the last decade in combining SRS data with EMs, with particular attention to the challenges modellers face for applications at local scales (e.g. small watersheds).
2. We critically review the literature on progress made towards integration of SRS data into terrestrial EMs: (1) as input to define model drivers; (2) as reference to validate model results; and (3) as a tool to sequentially update the state variables, and to quantify and reduce model uncertainty.
3. The number of applications provided in the literature shows that EMs may profit greatly from the inclusion of spatial parameters and forcings provided by vegetation and climatic‐related SRS products. Limiting factors for the application of such models to local scales are: (1) mismatch between the resolution of SRS products and model grid; (2) unavailability of specific products in free and public online repositories; (3) temporal gaps in SRS data; and (4) quantification of model and measurement uncertainties. This review provides examples of possible solutions adopted in recent literature, with particular reference to the spatiotemporal scales of analysis and data accuracy. We propose that analysis methods such as stochastic downscaling techniques and multi‐sensor/multi‐platform fusion approaches are necessary to improve the quality of SRS data for local applications. Moreover, we suggest coupling models with data assimilation techniques to improve their forecast abilities.
4. This review encourages the use of SRS data in EMs for local applications, and underlines the necessity for a closer collaboration among EM developers and remote sensing scientists. With more upcoming satellite missions, especially the Sentinel platforms, concerted efforts to further integrate SRS into modelling are in great demand and these types of applications will certainly proliferate
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