473 research outputs found

    Acoustic emission from composite materials

    Get PDF
    The two basic areas where the acoustic emission (AE) technique can be applied are materials research and the evaluation of structural reliability. This experimental method leads to a better understanding of fracture mechanisms and is an NDT technique particularly well suited for the study of propagating cracks. Experiments are described in which acoustic emissions were unambiguously correlated with microstructural fracture mechanisms. The advantages and limitations of the AE technique are noted

    ASTRI SST-2M prototype and mini-array simulation chain, data reduction software, and archive in the framework of the Cherenkov Telescope Array

    Get PDF
    The Cherenkov Telescope Array (CTA) is a worldwide project aimed at building the next-generation ground-based gamma-ray observatory. Within the CTA project, the Italian National Institute for Astrophysics (INAF) is developing an end-to-end prototype of the CTA Small-Size Telescopes with a dual-mirror (SST-2M) Schwarzschild-Couder configuration. The prototype, named ASTRI SST-2M, is located at the INAF "M.C. Fracastoro" observing station in Serra La Nave (Mt. Etna, Sicily) and is currently in the scientific and performance validation phase. A mini-array of (at least) nine ASTRI telescopes has been then proposed to be deployed at the Southern CTA site, by means of a collaborative effort carried out by institutes from Italy, Brazil, and South-Africa. The CTA/ASTRI team is developing an end-to-end software package for the reduction of the raw data acquired with both ASTRI SST-2M prototype and mini-array, with the aim of actively contributing to the global ongoing activities for the official data handling system of the CTA observatory. The group is also undertaking a massive Monte Carlo simulation data production using the detector Monte Carlo software adopted by the CTA consortium. Simulated data are being used to validate the simulation chain and evaluate the ASTRI SST-2M prototype and mini-array performance. Both activities are also carried out in the framework of the European H2020-ASTERICS (Astronomy ESFRI and Research Infrastructure Cluster) project. A data archiving system, for both ASTRI SST-2M prototype and mini-array, has been also developed by the CTA/ASTRI team, as a testbed for the scientific archive of CTA. In this contribution, we present the main components of the ASTRI data handling systems and report the status of their development.Comment: Proceedings of the 35th International Cosmic Ray Conference (ICRC 2017), Bexco, Busan, Korea. All CTA contributions at arXiv:1709.0348

    Solar-Powered Deep Learning-Based Recognition System of Daily Used Objects and Human Faces for Assistance of the Visually Impaired

    Get PDF
    This paper introduces a novel low-cost solar-powered wearable assistive technology (AT) device, whose aim is to provide continuous, real-time object recognition to ease the finding of the objects for visually impaired (VI) people in daily life. The system consists of three major components: a miniature low-cost camera, a system on module (SoM) computing unit, and an ultrasonic sensor. The first is worn on the user’s eyeglasses and acquires real-time video of the nearby space. The second is worn as a belt and runs deep learning-based methods and spatial algorithms which process the video coming from the camera performing objects’ detection and recognition. The third assists on positioning the objects found in the surrounding space. The developed device provides audible descriptive sentences as feedback to the user involving the objects recognized and their position referenced to the user gaze. After a proper power consumption analysis, a wearable solar harvesting system, integrated with the developed AT device, has been designed and tested to extend the energy autonomy in the dierent operating modes and scenarios. Experimental results obtained with the developed low-cost AT device have demonstrated an accurate and reliable real-time object identification with an 86% correct recognition rate and 215 ms average time interval (in case of high-speed SoM operating mode) for the image processing. The proposed system is capable of recognizing the 91 objects oered by the Microsoft Common Objects in Context (COCO) dataset plus several custom objects and human faces. In addition, a simple and scalable methodology for using image datasets and training of Convolutional Neural Networks (CNNs) is introduced to add objects to the system and increase its repertory. It is also demonstrated that comprehensive trainings involving 100 images per targeted object achieve 89% recognition rates, while fast trainings with only 12 images achieve acceptable recognition rates of 55%

    Stocking density affects welfare indicators in horses reared for meat production

    Get PDF
    Horses kept for meat production are reared in intensive breeding farms. We employed a checklist adapted from the Animal Welfare Indicators (AWIN) assessment protocol. Our evaluation aims to assess whether welfare indicators are influenced by stocking densities (m2/horse) and feeding strategies applied. An analysis was carried out on the data obtained from 7 surveys conducted at a single horse farm designed for meat production. In each survey, the same 12 pens were assessed, but on each occasion, the horses in the pens had been changed as had the stocking densities. Briefly, 561 horses aged 16 ± 8 months (mean ± standard deviation) were evaluated. Two stocking density cut-off values (median and 75th percentile: 3.95 and 4.75 m2/horse, respectively) were applied to investigate the effect of stocking density on horse welfare. Data were analysed using Mann–Whitney U and Fisher’s exact tests (p < 0.05). When cut-off was set as the median percentile, lower stocking density was associated with improvements in body condition score (BCS), coat cleanliness and bedding quantity, less coughing, less resting in a standing position, and less feeding related to the greater space available at the feed bunk. When the 75th percentile cut-off was used, indicators that improved were coat cleanliness, bedding quantity and mane and tail condition, as well as less resting in standing position and less feeding related to the greater space available at the feed bunk. Accordingly, the use of two different stocking density cut-off values showed that the increase of space allowance affected specific welfare indicators. Further increment of space and/or changes in management regimes should be investigated to improve all the indicators. Moreover, results related to feeding indicated the need to intervene as starch intakes exceeded recommended safe levels, negatively affecting horse welfare

    Facial nerve dehiscence and cholesteatoma: a comparison between decades

    Get PDF
    OBJECTIVES: To evaluate the incidence of facial canal dehiscence (FCD) and other intraoperative findings over the last 20 years as well as correlation with the Japanese Otological Society/European Academy of Otology and Neurotology classification in patients with cholesteatoma. MATERIALS and METHODS: A total of 469 patients operated from 1998 to 2018 were selected and divided into 2 groups of 10 years each. RESULTS: Dehiscence was significantly higher in patients with a history of pathology longer than 5 years (22.7%). Higher values were observed in revision surgery, 44.4% in the first period and 41.7% in the second. The tympanic segment was the one most frequently involved, affecting 92% of patients in the first period and 97% of patients in the second. Dehiscence occurred significantly more often in patients with a semicircular canal fistula, 14.8% in the first decade and 8.8% in the second. The incidence of FCD was significantly higher in patients with primary cholesteatoma (especially in those with combined pars tensa-flaccida) than in those with a secondary acquired one, 31.5% vs 7.4% in the first period, 21.1% vs 7.4% in the second, and in those with a stage III disease, 42% in the first period, 33.3% in the second. CONCLUSION: Patients with a shorter history of cholesteatoma as well as those not previously operated had a lower incidence of FCD. The tym-panic tract of the facial nerve remains the most frequent site of dehiscence, while the association between dehiscence and fistula of the semicircular canal remains strong. Patients with combined pars tensa-pars flaccida and stage III cholesteatoma have a higher incidence of FCD

    Risk factors for obstructive sleep apnea syndrome in children: state of the art

    Get PDF
    The obstructive sleep apnea syndrome (OSAS) represents only part of a large group of pathologies of variable entity called respiratory sleep disorders (RSD) which include simple snoring and increased upper airway resistance syndrome (UARS). Although the etiopathogenesis of adult OSAS is well known, many aspects of this syndrome in children are still debated. Its prevalence is about 2% in children from 2 to 8 years of age, mostly related to the size of the upper airways adenoid tissue. Several risk factors linked to the development of OSAS are typical of the pediatric age. The object of this paper is to analyze the state of the art on this specific topic, discussing its implications in terms of diagnosis and management

    Inhibition of Respiration by Nitric Oxide Induces a Mycobacterium tuberculosis Dormancy Program

    Get PDF
    An estimated two billion persons are latently infected with Mycobacterium tuberculosis. The host factors that initiate and maintain this latent state and the mechanisms by which M. tuberculosis survives within latent lesions are compelling but unanswered questions. One such host factor may be nitric oxide (NO), a product of activated macrophages that exhibits antimycobacterial properties. Evidence for the possible significance of NO comes from murine models of tuberculosis showing progressive infection in animals unable to produce the inducible isoform of NO synthase and in animals treated with a NO synthase inhibitor. Here, we show that O2 and low, nontoxic concentrations of NO competitively modulate the expression of a 48-gene regulon, which is expressed in vivo and prepares bacilli for survival during long periods of in vitro dormancy. NO was found to reversibly inhibit aerobic respiration and growth. A heme-containing enzyme, possibly the terminal oxidase in the respiratory pathway, likely senses and integrates NO and O2 levels and signals the regulon. These data lead to a model postulating that, within granulomas, inhibition of respiration by NO production and O2 limitation constrains M. tuberculosis replication rates in persons with latent tuberculosis

    Immunotherapy in the Treatment of Metastatic Melanoma: Current Knowledge and Future Directions

    Get PDF
    Melanoma is one of the most immunologic malignancies based on its higher prevalence in immune-compromised patients, the evidence of brisk lymphocytic infiltrates in both primary tumors and metastases, the documented recognition of melanoma antigens by tumor-infiltrating T lymphocytes and, most important, evidence that melanoma responds to immunotherapy. The use of immunotherapy in the treatment of metastatic melanoma is a relatively late discovery for this malignancy. Recent studies have shown a significantly higher success rate with combination of immunotherapy and chemotherapy, radiotherapy, or targeted molecular therapy. Immunotherapy is associated to a panel of dysimmune toxicities called immune-related adverse events that can affect one or more organs and may limit its use. Future directions in the treatment of metastatic melanoma include immunotherapy with anti-PD1 antibodies or targeted therapy with BRAF and MEK inhibitors

    Barriers associated with emergency medical service activation in Italian patients with ST-segment elevation acute coronary syndromes

    Get PDF
    Abstract Background Many ST-segment elevation acute coronary syndrome (STEACS) patients fail to activate the Emergency Medical System (EMS), with possible dramatic consequences. Prior studies focusing on barriers to EMS activation include patients with any acute coronary syndrome (ACS) without representation of southern European populations. However, barriers are influenced by the ACS type and by socio-demographic and racial factors. Purpose We aimed to investigate the barriers to EMS call for patients diagnosed for STEACS in Italy. Methods A prospective, single-center, survey-based study, including all the patients treated with primary percutaneous coronary intervention for STEACS in a tertiary hospital in northern Italy from 1st June 2018 to 31st May 2020. Results The questionnaire was filled out by 293 patients. The majority of the participants were males (74%), married (70.4%), with a high-school degree (38.4%) and with a median age of 62 years. Chest pain as a possible symptom related to a cardiovascular attack is known by most of the respondents (89%), and left arm pain/shake by 53.7% of them, whilst the other possible signs and symptoms (i.e. dyspnea, asthenia, sweating, nausea, vomiting, dizziness) were unknown to the majority of the participants. Only 191 (65.2%) of the participants activated the EMS after symptoms onset. The main reasons for not calling EMS were the perception that symptoms were not related to an important health problem (45.5%) and that a private vehicle is faster than EMS to reach the hospital (34.7%). The median time to first medical contact was 60 minutes, and it was significantly higher in the patients who did not called EMS compared to those who did (180 [60–420] mins vs 35 [15–120] mins, p<0.001). The patients who called a private doctor after symptoms onset did not called EMS more frequently than those who did not (5.9% vs 8.2%, p=0.3). Moreover, 30% of the patients who did not call the EMS would still act in the same way if a new episode occurred and the main reasons for this were that they think to be faster than EMS (57.1%) and to live close to the hospital (17.9%). Analyzing predictors of EMS activation, only prior history of cardiovascular disease has been demonstrated to be a predictor of calling the EMS in case of symptoms suspected for STEACS. Conclusions Our study, from the southern Europe, showed that a substantial percentage of patients with symptoms suspected for STEACS preferred private vehicle rather than activating the EMS. Our results highlight the need for information campaigns targeted to both the general population and medical doctors, stressing that the EMS is faster than a private vehicle to direct the patient to the right hospital and increasing the awareness of the people on the type of possible heart attack symptoms, which seem to be the most neglected issues by patients who did not call the EMS. Funding Acknowledgement Type of funding sources: None
    • …
    corecore