608 research outputs found

    Effect of Pruning Severity on Yield, Drying Time and Wages in Flame Seedless Dry-on-vine and Traditional Raisin Production Systems in Argentina

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    Raisin grapes are potentially more profitable than wine grapes in San Juan, Argentina, although the traditional system of grape drying requires an extensive use of costly labour. Production costs might be reduced by adopting the dry-on-vine (DOV) raisin-making system, but the feasibility of DOV in Argentina has not been assessed, and neither have the costs and pruning schemes. Thus we determined drying time and yields, estimated wages per hectare, and determined the influence of pruning severity on Flame Seedless raisin grapes. A completely random design with six treatments and six replicates was used in the 2013 to 2016 seasons. The treatments comprised differences in the nodes per cane, nodes per vine,distribution of nodes, and sugar content. Descriptive statistics and variance analysis were calculated for fresh fruit weight, dry fruit weight, drying ratio and drying time. The leaf area and its relationship with dried fruit weight also were calculated. These data were processed with the Infostat program. The DOV system demands between 11 and 31 additional days during the drying period and reduces labour costs by between 38% and 64% compared to the traditional system. Long pruning with the same load of buds is better. Furthermore, the DOV system is not associated with a lower production and thus appears to be a financially sustainable alternative to traditional production systems for Flame Seedless raisin grape producers in Argentina

    Non-linear Isolator for Vibration and Force Transmission Control of Unbalanced Rotating Machines

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    Purpose: The objective of this paper is to investigate with simulations how non-linear spring and non-linear damper components of isolators can be employed to effectively reduce both the oscillations and the force transmitted to ground in the whole spinning range of unbalanced rotating machines. Methods: The principal goal of this paper is twofold. First, to present a concise and consistent formulation based on the harmonic balance approach for the vibration response of spinning machines mounted on linear/non-linear, softening/hardening, un-tensioned/pre-tensioned springs and linear/non-linear dampers. Second, to provide a comprehensive overview of the vibration and force transmission control with non-linear isolators specifically tailored to unbalanced machines. Results: The study has shown that, the best vibration isolation is provided by a pre-tensioned linear and cubic softening spring combined with a linear and negative quadratic damper. The pre-tensioned spring should be designed in such a way as it holds the weight of the machine and thus produces on the vibrating machine a symmetric elastic restoring force proportional to the linear and cubic powers of the displacement. The cubic softening stiffness should then be tuned to minimise the frequency, and thus the amplitude, of the resonant response of the fundamental mode of the machine and elastic suspension system, while preserving stability and a desired static deflection. In parallel, to reduce the force transmission to ground above the fundamental resonance frequency, the negative quadratic damping effect should be tailored to maximize the energy absorption at higher frequencies. Conclusion: The study has shown that non-linear spring and non-linear damper components can be effectively employed to control the vibration and force transmission in the whole spinning range of the machine. In particular, a pre-tensioned softening cubic non-linear spring can be used to mitigate the vibration and force transmission at low frequencies, close to the fundamental natural frequencies of the elastically suspended machine. Also, a negative quadratic non-linear damper can be used to tailor the energy dissipation of the isolator in such a way as to have high damping at low frequencies and low damping at higher frequencies, which enhances the vibration and force transmission control at low frequencies and, rather importantly, mitigates the force transmission at higher frequencies

    A Clostridium difficile outbreak in an Italian hospital: The efficacy of the multi-disciplinary and multifaceted approach

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    Introduction. We described an outbreak of C. difficile that occurred in the Internal Medicine department of an Italian hospital and assessed the efficacy of the measures adopted to manage the outbreak. Methods. The outbreak involved 15 patients and was identified by means of continuous integrated microbiological surveillance, starting with laboratory data (alert organism surveillance). Diarrheal fecal samples from patients with suspected infection by C. difficile underwent rapid membrane immuno-enzymatic testing, which detects both the presence of the glutamate dehydrogenase antigen and the presence of the A and B toxins. Extensive microbiological sampling was carried out both before and after sanitation of the environment, in order to assess the efficacy of the sanitation procedure. Results. The outbreak lasted one and a half month, during which time the Committee for the Prevention of Hospital Infections ordered the implementation of multiple interventions, which enabled the outbreak to be controlled and the occurrence of new cases to be progressively prevented. The strategies adopted mainly involved patient isolation, reinforcement of proper hand hygiene techniques, antimicrobial stewardship and environmental decontamination by means of chlorine-based products. Moreover, the multifaceted management of the outbreak involved numerous sessions of instruction/training for nursing staff and socio-sanitary operatives during the outbreak. Sampling of environmental surfaces enabled two sites contaminated by C. difficile to be identified. Conclusions. Joint planning of multiple infection control practices, together with effective communication and collaboration between the Hospital Infections Committee and the ward involved proved to be successful in controlling the outbreak

    Robust thalamic nuclei segmentation method based on local diffusion magnetic resonance properties.

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    The thalamus is an essential relay station in the cortical-subcortical connections. It is characterized by a complex anatomical architecture composed of numerous small nuclei, which mediate the involvement of the thalamus in a wide range of neurological functions. We present a novel framework for segmenting the thalamic nuclei, which explores the orientation distribution functions (ODFs) from diffusion magnetic resonance images at 3 T. The differentiation of the complex intra-thalamic microstructure is improved by using the spherical harmonic (SH) representation of the ODFs, which provides full angular characterization of the diffusion process in each voxel. The clustering was performed using the k-means algorithm initialized in a data-driven manner. The method was tested on 35 healthy volunteers and our results show a robust, reproducible and accurate segmentation of the thalamus in seven nuclei groups. Six of them closely matched the anatomy and were labeled as anterior, ventral anterior, medio-dorsal, ventral latero-ventral, ventral latero-dorsal and pulvinar, while the seventh cluster included the centro-lateral and the latero-posterior nuclei. Results were evaluated both qualitatively, by comparing the segmented nuclei to the histological atlas of Morel, and quantitatively, by measuring the clusters' extent and the clusters' spatial distribution across subjects and hemispheres. We also showed the robustness of our approach across different sequences and scanners, as well as intra-subject reproducibility of the segmented clusters using additional two scan-rescan datasets. We also observed an overlap between the path of the main long-connection tracts passing through the thalamus and the spatial distribution of the nuclei identified with our clustering algorithm. Our approach, based on SH representations of the ODFs, outperforms the one based on angular differences between the principle diffusion directions, which is considered so far as state-of-the-art method. Our findings show an anatomically reliable segmentation of the main groups of thalamic nuclei that could be of potential use in many clinical applications

    How social start-ups avoid being falling stars when developing social innovation

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    The aim of this study is to provide new insights into the social innovation (SI) development process in the context of social start-ups. A multiple case study identifies the issues and mechanisms for social start-ups to develop a social need into a potentially scalable innovation and to validate and scale it up, while avoiding a possible failure. Results show that key challenges faced by social start-ups can be characterized according to the stage of the SI development path. Firstly, social start-ups' failure can be caused by the lack of expertise in social problems and of flexible processes for social ventures creation; secondly, by the lack of awareness of SI benefits and proper resources allocation; and, finally, by a weak understanding of the impact and intangible outcomes of the developed SI in society, while ensuring its economic sustainability. Successfully overcoming these challenges requires social start-ups to put in place the following mechanisms: (1) leveraging a vision and motivations that balance tensions in terms of the radical, economic and cultural aspects of SI; (2) engaging the SI stakeholders in different (and sequential) phases of SI development process; and (3) identifying and adopting the most suitable technological, financial and communication tools in an integrated way

    Avaliação da dor no ombro em paciente com acidente vascular cerebral

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    O objetivo desse estudo preliminar é avaliar as causas de dor no ombro de pacientes hemiplégicos, bem como verificar a ocorrência e a evolução do tratamento da síndrome dolorosa miofascial (SDMF). Para isso, seis pacientes hemiplégicos (cinco espásticos grau II, segundo Ashworth e um flácido) com idade: 55, 85 +/- 1, 50 anos, tempo de AVC de 6, 85 +/- 2, 54 meses, e queixas de dor no ombro paralisado há 13, 33 +/- 1, 69 semanas, foram submetidos a um protocolo de avaliação qualitativa (questionário de MacGuill simplificado e quantitativa por meio da escala visual analógica – EVA e dolorimetria de pressão), além da avaliação goniométrica ativa e passiva do ombro. Todos os pacientes apresentaram à palpação muscular, SDMF associada e foram infiltrados com lidocaína a 1% em pontos-gatilho (PGs) intramusculares. As queixas predominantes foram dor em queimor em quatro, peso em três e incaracterística em dois. Nenhum paciente referiu queixas de formigamento, choque, adormecimento e agulhadas. Quatro pacientes foram infiltrados em PGs na musculatura posterior do ombro, um em bíceps e outro em peitoral maior. Não houve melhora significativa na evolução dolorimétrica de pressão e na goniometria após a infiltração desses PGs (p > 0,05). Nesse estudo, diagnosticamos por meios clínicos e/ou radiológicos (RX e USG): um paciente com capsulite adesiva, um com tendinite bicipital e outro com tendinite no supra-espinhal. Não se diagnosticou subluxação na articulação glenoumeral, nem sinais clínicos de lesão nervosa periférica.Shoulder pain evaluation in stroke patients The purpose of this pilot study is to evaluate the causes of the shoulder pain in the hemiplegic patient as well as the evolution of the miofascial pain syndrome after treatment. Six patients, with 55, 85 +/- 1, 50 years old with an average period from the stroke of 6, 85 +/- 2, 54 months and shoulder pain for 13, 33 +/- 1, 69 weeks, were studied by simplified MacGuill questions; VAS (visual analogue scale), pressure dolorimetry, active and passive goniometric evaluation. Five were spastic grade II and one was flaccid according to Ashworth scale. Six patients had miofascial pain and were submitted by lidocaine 1% injection in trigger points: four in the back shoulder muscles, one in biceps and another in the large pectoral muscles. The characteristics of pain were: burning in four, heavy in three and undefined in two patients. None of them complained of “pins or needles” and “electrical shock” sensation. Three patients referred good results, two regular and one bad. The VAS, the dolorimetric pressure and the goniometric evaluations didn’t show significant improvement after injection (p > 0.05). This study found one patient with adhesive capsulitis; one with supraspinatus tendinitis and another with bicipital tendonitis, by clinical and ultrassonografic evaluation, respectively. There weren’t any patient with shoulder subluxation nor brachial plexus injury. Although with few patients, this study indicates the importance of the approach to miofascial pain syndrome in shoulder pain of hemiplegic patients

    Planar AFM macro-probes to study the biomechanical properties of large cells and 3D cell spheroids

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    The ability to measure mechanical response of cells under applied load is essential for developing more accurate models of cell mechanics and mechanotransduction. Living cells have been mechanically investigated by several approaches. Among them, atomic force microscopy (AFM) is widely used thanks to its high versatility and sensitivity. In the case of large cells or 3D multicellular aggregates, standard AFM probes may not be appropriate to investigate the mechanical properties of the whole biological system. Owing to their size, standard AFM probes can compress only a single somatic cell or part of it. To fill this gap, we have designed and fabricated planar AFM macro-probes compatible with commercial AFM instruments. The probes are constituted of a large flat compression plate, connected to the chip by two flexible arms, whose mechanical characteristics are tuned for specific biological applications. As proof of concept, we have used the macro-probes to measure the viscoelasticity of large spherical biological systems, which have a diameter above 100 \u3bcm: human oocytes and 3D cell spheroids. Compression experiments are combined with visual inspection, using a side-view configuration imaging, which allows us to monitor the sample morphology during the compression and to correlate it with the viscoelastic parameters. Our measurements provide a quantitative estimate of the relaxation times of such biological systems, which are discussed in relation to data present in literature. The broad applicability of the AFM macro-probes can be relevant to study the biomechanical features in any biological process involving large soft materials. Statement of Significance: The understanding of the role of physical factors in defining cell and tissue functions requires to develop new methods or improve the existing ones to accurately measure the biomechanical properties. AFM is a sensitive and versatile tool to measure the mechanical features from single proteins to single cells. When cells or cell aggregates exceed few tens of microns, AFM suffers from limitations. On these biological systems the control of the contact area and the application of a precise uniform compression becomes crucial. A modification of the standard cantilevers fabrication allowed us obtaining AFM macro-probes, having large planar contact area and spring constant suitable for biological investigations. They were demonstrated valuable to characterize the mechanical properties of large hierarchical biological systems

    Effects of X-ray irradiation on haemocytes of Procambarus clarkii (Arthropoda: Decapoda) males

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    The red swamp crayfish Procambarus clarkii is an invasive alien species spreading worldwide. The sterile male release technique (SMRT) is among the methods used to contrast the growth of P. clarkii populations within invaded areas. In this study males underwent X-ray sterilisation with a dose of 40 Gy and their immunocompetence was analysed in comparison to untreated animals to ascertain whether radiation can affect welfare parameters other than reproductive organs. The present research investigated the immune function in P. clarkii males in term of (1) morphological haemocyte characterisation by transmission electron microscopy to identify the main phagocyting haemocyte after in vivo artificial non-self challenge with latex beads; (2) total and differential haemocyte counts; and (3) basal and total phenoloxidase activities as components of the humoral defence. Three types of circulating haemocytes were characterised via transmission electron microscopy: hyaline, semigranular and granular haemocytes. The ultrastructural features of haemocyte granules allowed the characterisation of a fourth type of haemocyte, the medium granule haemocyte. In vivo artificial non-self-challenge with latex beads identified the semigranular haemocytes as primarily involved in phagocyting activity. Circulating haemocytes of males irradiated with a dose of 40 Gy, after 20 days, showed a significantly lower diameter in the granules of hyaline and semigranular haemocytes, but no other evident ultrastructural alterations in comparison with un-irradiated animals were found. Irradiated males showed a significant decrease of about 80% of circulating haemocytes and an increase in frequency of semigranular and granular haemocytes. No significant differences in basal and total phenoloxidase activity were recorded and this could, in part, explain the good survival level of irradiated males despite the drastic decline of the haemocyte number. This study represents the basis to appraise whether SMRT affects important functions, such as those of the immune system, in addition to altering the gonad tissue
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