Satellite-Based Tele-Operation of an Underwater Vehicle-Manipulator System. Preliminary Experimental Results

Within the European project DexROV the topic of underwater intervention is addressed. In particular, a remote control room is connected through a satellite communication link to surface vessel, which is in turn connected to an UVMS (Underwater Vehicle-Manipulator System) with an umbilical cable. The operator may interact with the system using a joystick or exoskeleton. Since a direct teleoperation is not feasible, a cognitive engine is in charge of handling communication latency or interruptions caused by the satellite link, and the UVMS should have sufficient autonomy in dealing with low level constraints or secondary objectives. To this purpose, a task-priority-based inverse kinematics algorithm has been developed in order to allow the operator to control only the end effector, while the algorithm is in charge of handling both operative and joint-space constraints. This paper describes some preliminary experimental results achieved during the DexROV campaign of July 2017 in Marseilles (France), where most of the components have been successfully integrated and the inverse kinematics nicely run

Combination therapy with warfarin plus clopidogrel improves outcomes in femoropopliteal bypass surgery patients

Background: Patients having undergone femoropopliteal bypass surgery remain at significant risk of graft failure. Although antithrombotic therapy is of paramount importance in these patients, the effect of oral anticoagulation therapy (OAT) on outcomes remains unresolved. We performed a randomized, prospective study to assess the impact of OAT plus clopidogrel vs dual antiplatelet therapy on peripheral vascular and systemic cardiovascular outcomes in patients who had undergone femoropopliteal bypass surgery. Methods: Three hundred forty-one patients who had undergone femoropopliteal surgery were enrolled and randomized: 173 patients received clopidogrel 75 mg/d plus OAT with warfarin (C + OAT), and 168 patients received dual antiplatelet therapy with clopidogrel 75 mg/d plus aspirin 100 mg/d (C + acetylsalicylic acid [ASA]). Study end points were graft patency and the occurrence of severe peripheral arterial ischemia, and the incidence of bleeding episodes. Results: Follow-up ranged from 4 to 9 years. The graft patency rate and the freedom from severe peripheral arterial ischemia was significantly higher in C + OAT group than in C + ASA group (P =.026 and.044, respectively, Cox-Mantel test). The linearized incidence of minor bleeding complications was significantly higher in C + OAT group than in C + ASA group (2.85% patient-years vs 1.37% patient-years; P =.03). The incidence of major adverse cardiovascular events, including mortality, was found to be similar (P =.34) for both study groups. Conclusions: In patients who have undergone femoropopliteal vascular surgery, combination therapy with clopidogrel plus warfarin is more effective than dual antiplatelet therapy in increasing graft patency and in reducing severe peripheral ischemia. These improvements are obtained at the expenses of an increase in the rate of minor anticoagulation-related complications. © 2012 Society for Vascular Surgery

Imaging performance of phase-contrast breast computed tomography with synchrotron radiation and a CdTe photon-counting detector

Purpose: Within the SYRMA-CT collaboration based at the ELETTRA synchrotron radiation (SR) facility (Trieste, Italy) the authors investigated the imaging performance of the phase-contrast computed tomography (CT) system dedicated to monochromatic in vivo 3D imaging of the female breast, for breast cancer diagnosis. Methods: Test objects were imaged at 38 keV using monochromatic SR and a high-resolution CdTe photon-counting detector. Signal and noise performance were evaluated using modulation transfer function (MTF) and Noise Power Spectrum (NPS). Phase-contrast CT images as well as images obtained after the application of a phase-retrieval algorithm were evaluated. The contrast to noise ratio (CNR) and the capability of detecting test microcalcification clusters and soft masses were explored. Results: For a voxel size of (60 \u3bcm)3, phase-contrast images showed higher spatial resolution (6.7 mm-1 at 10% MTF) than corresponding phase retrieval images (2.5 mm-1). Phase retrieval produced a reduction of the noise level as well as an increase of the CNR by more than one order of magnitude, compared to raw phase-contrast images. CaCO3 microcalcifications with a diameter down to 130 \u3bcm were detected both in phase-contrast and in phase retrieval images of the test object. Conclusions: The investigation on test objects indicates that breast CT with a monochromatic SR source is technically feasible in terms of spatial resolution, image noise and contrast, for in vivo 3D imaging with a dose comparable to that of two-view mammography. Phase-retrieved images showed the best performance in the trade-off between spatial resolution and image noise

Use of XR-QA2 radiochromic films for quantitative imaging of a synchrotron radiation beam

This work investigates the use of XR-QA2 radiochromic films for quantitative imaging of a synchrotron radiation (SR) beam. Pieces (200 7 30 mm2) of XR-QA2 film were irradiated in a plane transverse to the beam axis, at the SYRMEP beamline at ELETTRA (Trieste), with a monochromatic beam of size 170 7 3.94 mm2 (H 7 V) and energy of 28, 35, 38 or 40 keV. The response was calibrated in terms of average air kerma (1\uf02d20 mGy), measured with a calibrated ionization chamber. Films were digitized in reflectance mode using a flatbed scanner. The 16-bit red channel was used. The net\uf020reflectance was then converted to photon fluence per unit air kerma (mm-2 mGy-1). The SR beam profile was acquired also with a scintillator (GOS) based, fiberoptic coupled CCD camera as well as with a scintillator based flat panel detector. Horizontal profiles obtained with the two modalities were compared, evaluated in a ROI of 17.71 7 0.59 mm2, across the beam centre. Once corrected for flat field, the CCD profile was scaled in order to have the same average value as the normalized profile acquired with the gafchromic film. The same procedure was followed for the beam images acquired with the flat panel detector. Horizontal and vertical line profiles acquired with the radiochromic film show an uneven 2D distribution of the beam intensity, with variations in the order of 15\uf02d20% in the horizontal direction, while the statistical uncertainties evaluated for the radiochromic dose measurements were 6% at 28 keV. Larger variations up to 64% were observed in the vertical direction. The response of the radiochromic film is comparable to that of the other imaging detectors, within less than 5% variation

Set-based Inverse Kinematics Control of an Anthropomorphic Dual Arm Aerial Manipulator

The paper presents a multiple task-priority inverse kinematics algorithm for a dual-arm aerial manipulator. Both tasks defined as equality constraints and inequality constraints are handled by means of a singularity robust method based on the Null-Space based Behavioral control. The proposed schema is constituted by the inverse kinematics control, that receives the desired behavior of the system and outputs the reference values for the motion variables, i.e. the UAV pose and the arm joints position, and a motion control, that computes the vehicle thrusts and the joint torques. The method has been experimentally validated on a system composed by an underactuated aerial hexarotor vehicle equipped with two lightweight 4-DOF manipulators, involved in operations requiring the coordination of the two arms and the vehicle

Sfrp1 deficiency makes retinal photoreceptors prone to degeneration

Millions of individuals worldwide suffer from impaired vision, a condition with multiple origins that often impinge upon the light sensing cells of the retina, the photoreceptors, affecting their integrity. The molecular components contributing to this integrity are however not yet fully understood. Here we have asked whether Secreted Frizzled Related Protein 1 (SFRP1) may be one of such factors. SFRP1 has a context-dependent function as modulator of Wnt signalling or of the proteolytic activity of A Disintegrin And Metalloproteases (ADAM) 10, a main regulator of neural cell-cell communication. We report that in Sfrp1^{-/-} mice, the outer limiting membrane (OLM) is discontinuous and the photoreceptors disorganized and more prone to light-induced damage. Sfrp1 loss significantly enhances the effect of the Rpe6^{Leu450Leu} genetic variant -present in the mouse genetic background- which confers sensitivity to light-induced stress. These alterations worsen with age, affect visual function and are associated to an increased proteolysis of Protocadherin 21 (PCDH21), localized at the photoreceptor outer segment, and N-cadherin, an OLM component. We thus propose that SFRP1 contributes to photoreceptor fitness with a mechanism that involves the maintenance of OLM integrity. These conclusions are discussed in view of the broader implication of SFRP1 in neurodegeneration and aging

An easier life to come for mosquito researchers. Field-testing across Italy supports Vectrack system for automatic counting, identification and absolute density estimation of Aedes albopictus and Culex pipiens adults

Background: Disease-vector mosquito monitoring is an essential prerequisite to optimize control interventions and evidence-based risk predictions. However, conventional entomological monitoring methods are labor- and time- consuming and do not allow high temporal/spatial resolution. In 2022, a novel system coupling an optical sensor with machine learning technologies (VECTRACK) proved efective in counting and identifying Aedes albopictus and Culex pipiens adult females and males. Here, we carried out the first extensive field evaluation of the VECTRACK system to assess: (i) whether the catching capacity of a commercial G-Mosquitaire trap (BGM) for adult mosquito equipped with VECTRACK (BGM+VECT) was afected by the sensor; (ii) the accuracy of the VECTRACK algorithm in correctly classifying the target mosquito species genus and sex; (iii) Ae. albopictus capture rate of BGM with or without VECTRACK. Methods: The same experimental design was implemented in four areas in northern (Bergamo and Padua districts), central (Rome) and southern (Procida Island, Naples) Italy. In each area, three types of traps—one BGM, one BGM+VECT and the combination of four sticky traps (STs)—were rotated each 48 h in three diferent sites. Each sampling scheme was replicated three times/area. Collected mosquitoes were counted and identifed by both the VECTRACK algorithm and operator-mediated morphological examination. The performance of the VECTRACK system was assessed by generalized linear mixed and linear regression models. Aedes albopictus capture rates of BGMs were calculated based on the known capture rate of ST. Results: A total of 3829 mosquitoes (90.2% Ae. albopictus) were captured in 18 collection-days/trap/site. BGM and BGM+VECT showed a similar performance in collecting target mosquitoes. Results show high correlation between visual and automatic identifcation methods (Spearman Ae. albopictus: females=0.97; males=0.89; P<0.0001) and low count errors. Moreover, the results allowed quantifying the heterogeneous efectiveness associated with diferent trap types in collecting Ae. albopictus and predicting estimates of its absolute density. Conclusions: Obtained results strongly support the VECTRACK system as a powerful tool for mosquito monitoring and research, and its applicability over a range of ecological conditions, accounting for its high potential for continuous monitoring with minimal human effort

Caracterización en contenido de fenoles y azúcares totales en distintas variedades de arándanos cultivados en La Plata

El arándano es un frutal perteneciente al género Vaccinium, de la familia de las Ericáceas y constituye un grupo de especies ampliamente distribuidas en el Hemisferio Norte. En Argentina la plantación de arándanos comenzó a expandirse a partir de 1993, en gran medida por su adaptación a las condiciones agroecológicas, alta rentabilidad y elevada demanda externa. Argentina tiene la ventaja de producir en contraestación en relación a los principales países productores y consumidores, comenzando la cosecha a mediados de septiembre y extendiéndose hasta mediados del mes de diciembre. En cuanto a las propiedades nutracéuticas, tienen alta concentración de compuestos bioactivos, muy valorados por sus beneficios en la salud. Dentro de estos compuestos están los polifenoles, incluyendo antocianinas, ácidos fenólicos, taninos, carotenoides, vitaminas A, C, E, ácido fólico y minerales como el calcio, selenio y cinc. Los fenoles son metabolitos secundarios distribuidos en los vegetales, que cumplen diversas funciones en las plantas, como protectores frente a las radiaciones ultravioleta, y forman los pigmentos naturales de las plantas (p.ej., antocianinas, flavonas y flavonoles), intervienen como reguladores de interacciones plantamicroorganismos, están implicados en procesos defensivos, así como efectos alelopáticos y de atracción de polinizadores. Algunos fenoles también juegan un importante papel en la tolerancia al estrés. El contenido de azúcares de los frutos influye en gran medida en el sabor, y este parámetro de calidad puede variar según el material genético, época de cosecha, madurez a cosecha y manejo del cultivo entre otros. El objetivo de este trabajo fue determinar diferencias en la calidad general y nutracéutica de cuatro variedades de arándanos en condiciones de cultivo de la localidad de La Plata. Las muestras fueron tomadas de la Estación Experimental “Julio Hirschhorn” (34º54´ LS). El monte de arándanos está conducido en líneas cada 3m y 1m entre plantas, con mínimas prácticas de podas y controles de maleza, sin aplicaciones de productos fitosanitarios.Facultad de Ciencias Agrarias y Forestale