3,457 research outputs found

    A new hybrid PSO algorithm based on a stochastic Markov chain model

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    International audienceBased on the recent research concerning the PageRank Algorithm used in the famous search engine Google, a new Inverse-PageRank-Particle Swarm Optimizer (I-PR-PSO) is presented in order to improve the performances of classic PSO. The resulted algorithm uses a stochastic Markov chain model to define an intelligent topological structure of the swarm's population, in which the better particles have an important influence on the others. In the presented experiments, calculations on some benchmark functions classically used to test optimization methods are performed, and the results are compared to different versions of the standard PSO, that is using different topological structures of the population. The experimental results show that I-PR-PSO can converge quicker on the tested functions, and can find better results in the solution domain than its tested peers

    Dynamic Tests on a Steel Frame Equipped with Hysteretic and Visco-Re-Centring Energy Dissipating Bracing Systems

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    Abstract An extensive program of dynamic experimental tests, named JetPacs (Joint Experimental Testing on Passive and semiActive Control Systems), has been carried out at the Structural Laboratory of the University of Basilicata considering a 1:1.5 scaled three-dimensional steel frame, derived from a 2-storey, 1-bay prototype building. The JetPacs Project was developed within the RELUIS 2005-08 project, founded by Italian Dept. of Civil Protection. This work refers to the experimental tests on the model equipped with two different EDB systems based on Hysteretic Dampers (HD) and visco-re-centering devices (SMA+VD). The devices were designed with the purpose of limiting the inter-storey drifts so that the frame yielding is surely prevented. The visco-re-centering device was obtained by coupling Viscous Dampers (VD), with re-centering device based on shape memory alloy (SMA) wires, while the Hysteretic Damper was constituted by low-carbon U-shaped steel plates. The main objective of this paper is to compare the seismic response of the structure with SMA+VD and HD EDB's in order to calibrate a new performance based design procedure for the evaluation of the mechanical characteristics of SMA+VD devices. In this paper, the experimental results of the shaking table tests, in terms of comparison of both design solutions which lead to a comparable level of protection for the framed structure, are shown. The results obtained by numerical nonlinear time history analysis (NTHA) of both design solutions are also showed and compared with experimental ones

    Mixed trichuroid infestation in a dog from Italy

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    Background: Capillaria aerophila, Capillaria boehmi and Trichuris vulpis are trichuroid nematodes affecting wild and companion animals all over the World. The canine intestinal whipworm, T. vulpis, is the most common and wellknown in veterinary practice, whereas the respiratory C. aerophila and C. boehmi have been rarely reported in pets as a likely consequence of overlapping morphometric and morphological features of the eggs, which impair a correct etiological diagnosis. Findings: In December 2011, a mixed infestation by T. vulpis, C. aerophila and C. boehmi was diagnosed in an asymptomatic dog living in central Italy. Morphometric and morphological findings and pictures of the eggs found at the copromicroscopic analysis are herein reported. Conclusions: The present work demonstrates that when trichuroid eggs are found in a faecal sample from a dog, a careful morphological and morphometric analysis of individual parasite elements is mandatory. Key diagnostic features (i.e., size, wall surface pattern and aspects of plugs) should be carefully examined when eggs with overlapping shape and appearance are detected. In conclusion, given the importance in clinical practice of canine trichuroids and the zoonotic potential of C. aerophila, these nematodes should be included into the differential diagnosis of intestinal and respiratory parasitoses of dogs by a thorough microscopic analysis of all trichuroid ova present in microscopic fields

    Prevalence of zoonotic helminths in italian house dogs

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    Introduction: Dogs may act as potential sources of zoonotic parasites, e.g. intestinal helminths like Toxocara spp., Ancylostoma spp., Echinococcus spp. In particular circumstances, the environment contaminated by parasitic elements represents a source of infection for people and animals. The present study has evaluated the presence of zoonotic helminths in house dogs from central and north-eastern Italy. Methodology: Stool samples from 493 dogs were examined by a qualitative copromicroscopic technique and differences in prevalence of zoonotic parasites were statistically examined in relation to canine individual data. Results: 48/493 (9.7%) were positive for at least one parasite. Helminths recovered were Trichuris vulpis (5.5%), Toxocara canis (4.3%), Ancylostoma spp. (0.6%) and Eucoleus aerophilus (0.4%), while no cestodes were detected. Age and living with other dogs resulted risk factors for T. canis infection. Conclusions: The health risk associated with the occurrence of parasitic nematodes in privately owned dogs, along with the current anthelmintic treatment plans, are discussed

    Endoparasites of european wildcats (Felis silvestris) in Greece

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    The European wildcat (Felis silvestris) is the only wild felid living in Greece. Wildcat populations are declining due to anthropogenic and phenological unfavourable conditions, and parasites may have an additional negative impact. In the present study, the occurrence of endoparasites in wildcats in Greece and the potential threats posed to wildcats, domestic animals, and humans in the study areas has been investigated. In a six-year period, 23 road-killed wildcats and 62 wildcat faecal samples were collected from different areas of the country. Necropsy for the detection of endopara-sites and standard parasitological examinations of faecal samples were performed. Parasites were morphologically identified and, in selected cases, molecularly analysed. All necropsied wildcats (100%) were infected by three to 10 different parasite taxa, with the most prevalent being Taenia taeniaeformis (73.9%), Toxocara cati (60.9%), Angiostrongylus chabaudi (56.5%), Ancylostoma tubaeforme (39.1%), Cylicospirura spp. (34.8%), Troglostrongylus brevior (34.8%), and Capillaria aerophila (33.8%). Of the 62 faecal samples examined, 53 (85.5%) were positive for one or more parasite elements (larvae, eggs, or oocysts). The most frequent were T. cati (45.2%), A. chabaudi (29%), C. aerophila (24.2%), and Ancylostomatidae (17.7%). This is the first survey on endoparasites affecting wildcats in Greece. Some of the parasites here found are frequent in domestic and wild felids, while others, i.e., Oslerus rostratus and Cylicospirura petrowi, were described for the first time in the European wildcat. Most of them have a significant pathogenic potential, causing severe to hazardous diseases to infected felids and some, under specific circumstances, can also threaten human health

    Cat respiratory nematodes: Current knowledge, novel data and warranted studies on clinical features, treatment and control

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    The nematodes Aelurostrongylus abstrusus, Troglostrongylus brevior and Capillaria aerophila are the most important parasites inhabiting the airways of cats. They are receiving growing attention from academia, pharmaceutical companies and veterinarians, and are now considered a primary cause of respiratory diseases in feline clinical practice and parasitology. In the past few years, several studies have been conducted in both natural and experimental settings to increase knowledge, provide new insights and fill gaps on respiratory parasitoses of cats. Awareness and knowledge of clinical scenarios towards appropriate and timely diagnosis and prompt and efficacious treatment options have become a priority to investigate. At the same time, chemopreventative approaches have been evaluated to assess the geographical spreading of these parasites and the rise in the number of clinical cases in cat populations of different countries. Given the intense accumulation of novel data, this review presents and discusses the state of the art and the latest updates on the clinical features, treatment, and control of major respiratory parasitoses of cats. Moreover, food for thought is also provided with the aim of spurring on new studies in the near future

    Continuous rate infusion of dexmedetomidine vs subcutaneous administration in anaesthetized horses undergoing MRI examination

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    Up to 2005, dexmedetomidine use had not been reported in equine. Since then, several experimental and clinical studies have been published. The main reason for this increase relies on its beneficial pharmacological profile, including short half-life and rapid redistribution (1). The aim of the study is to compare the clinical effects and recovery quality after continuous rate infusion (CRI) or subcutaneous administration of dexmedetomidine in horses undergoing general anaesthesia. Fourteen horses scheduled for MRI examination were included. All horses were sedated with acepromazine 0.03 mg kg-1 intravenously (IV) and detomidine 10 \ub5g kg-1 (IV). Anaesthesia was induced with ketamine 3 mg kg-1 (IV) and diazepam 0.04 mg kg-1 (IV) and maintained with isofluorane in 60% oxygen; end-tidal isoflurane concentration was maintained between 1.3-1.4 %. Horses were randomly divided in two groups. Group \u201cDex CRI\u201d received dexmedetomidine intravenously at 1 \ub5g kg-1 hour-1, group \u201cDex SC\u201d received 2 \ub5g kg-1 of dexmedetomidine subcutaneously every 60 minutes. If nystagmus or incessant fighting against ventilator occurred, ketamine rescue at 0.1 mg kg-1 was given. In case of sudden movements, thiopental 0.5-1.0 mg kg-1 IV was given. Ringer\u2019s lactate was given at 3 mL kg-1 hour-1, dobutamine was administered IV and the rate adjusted to maintain MAP>70 mmHg. Controlled mechanical ventilation using intermittent positive pressure ventilation was adjusted to maintain arterial carbon dioxide partial pressure between 38-45 mmHg. Heart rate, invasive arterial blood pressure, arterial blood gases, total dose of dobutamine administered, ketamine rescue needed, urine production were recorded. Time required until extubation and time to attain sternal and standing position were noted. The main anaesthesiologist assessed recovery quality graded on a standard scoring 5-point scale with a score of 1 representing the best recovery (2). Mann-Whitney U test was applied for non-parametric data and T-test for parametric data (p 640.05). There was no statistically differences in physiological intra-anaesthetic parameters, in body weight (kg) (CRI 521\ub153; SC 506\ub176), age (years) (CRI 10.7\ub12.1; SC 10.8\ub14.1), anaesthesia duration (min) (CRI 139\ub19.,7; SC 144\ub116.2), number of ketamine rescue needed (CRI 1\ub11.15; SC 0.5\ub11.13), recovery score (CRI 1.8\ub11,2; SC 1.5\ub10,5). Also time until extubation (min) (CRI 11.5\ub15.0; SC 9.7\ub12.6), time to attain sternal (min) (CRI 41.5\ub112.2; SC 49.7\ub16.0) and standing position (min) (CRI 50.7\ub114.6; SC 57.2\ub16.,0) were not statistically different. There was statistical significance in urine production (L) (CRI 8.0\ub13.5; SC 11.1\ub14.4) and total dobutamine mcg/kg/min (CRI 0.89\ub10.35; SC 0.56\ub10.18). Subcutaneous administration of dexmedetomidine has product similar clinical effects to those achieved with CRI. It has permitted a significative reduction in dobutamine administration and a more stable depth of anaesthesia confirmed by the lower number of rescue ketamine boluses required even if not statistically different. Further studies are required to evaluate different dosages both in CRI and subcutaneous administration

    NOACs added to WHO’s essential medicines list: recommendations for future policy actions

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    The introduction of non-vitamin K antagonists oral anticoagulants, a class of medicines which includes dabigatran, apixaban, edoxaban and rivaroxaban, has resulted in improvements in the safety and efficacy of non valvular atrial fibrillation treatment for stroke prevention, with significant reductions in stroke, intracranial haemorrhage, and mortality. For these reasons, a team of World Heart Federation Emerging Leaders led efforts to add non-vitamin K antagonists oral anticoagulants to the World Health Organization’s Model List of Essential Medicines in 2019. Following the inclusion of this class of medicines in the Essential Medicines List, this editorial proposes several recommendations to improve the accessibility, affordability and acceptability of non-vitamin K oral anticoagulants, especially in low- and middle-income settings, in order to successfully manage non-valvular atrial fibrillation and to lower the risk of stroke

    Relationships between constructional and visuospatial abilities in normal subjects and in focal brain-damaged patients.

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    We tested 125 normal subjects and 24 right and 22 left focal brain-damaged patients (RBD and LBD) on the Rey figure copying test and on a battery of perceptual and representational visuospatial tasks, in search of relationships between constructional and visuospatial abilities. Selected RBD and LBD were not affected by severe aphasia, unilateral spatial neglect or general intellectual defects. Both RBD and LBD showed defective performances on the constructional task with respect to normal subjects. As regards visuospatial tasks, both patient groups scored lower than normal subjects in judging angle width and mentally assembling geometrical figures; moreover, RBD, but not LBD, achieved scores significantly lower than healthy controls in judging line orientation and analyzing geometrical figures. Post-hoc comparisons did not reveal any significant differences between RBD and LBD. Multiple regression analysis showed that visuospatial abilities correlate with accuracy in copying geometrical drawings in normal subjects and in RBD, but not in LBD. From a theoretical perspective, these findings support the idea that visual perceptual and representational abilities do play a role in constructional skills
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