8,328 research outputs found

    Leave-one-out prediction error of systolic arterial pressure time series under paced breathing

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    In this paper we show that different physiological states and pathological conditions may be characterized in terms of predictability of time series signals from the underlying biological system. In particular we consider systolic arterial pressure time series from healthy subjects and Chronic Heart Failure patients, undergoing paced respiration. We model time series by the regularized least squares approach and quantify predictability by the leave-one-out error. We find that the entrainment mechanism connected to paced breath, that renders the arterial blood pressure signal more regular, thus more predictable, is less effective in patients, and this effect correlates with the seriousness of the heart failure. The leave-one-out error separates controls from patients and, when all orders of nonlinearity are taken into account, alive patients from patients for which cardiac death occurred

    Phase shifts of synchronized oscillators and the systolic/diastolic blood pressure relation

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    We study the phase-synchronization properties of systolic and diastolic arterial pressure in healthy subjects. We find that delays in the oscillatory components of the time series depend on the frequency bands that are considered, in particular we find a change of sign in the phase shift going from the Very Low Frequency band to the High Frequency band. This behavior should reflect a collective behavior of a system of nonlinear interacting elementary oscillators. We prove that some models describing such systems, e.g. the Winfree and the Kuramoto models offer a clue to this phenomenon. For these theoretical models there is a linear relationship between phase shifts and the difference of natural frequencies of oscillators and a change of sign in the phase shift naturally emerges.Comment: 8 figures, 9 page

    The absolute age of the globular cluster M15 using near-infrared adaptive optics images from PISCES/LBT

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    We present deep near-infrared (NIR) J, Ks photometry of the old, metal-poor Galactic globular cluster M\,15 obtained with images collected with the LUCI1 and PISCES cameras available at the Large Binocular Telescope (LBT). We show how the use of First Light Adaptive Optics system coupled with the (FLAO) PISCES camera allows us to improve the limiting magnitude by ~2 mag in Ks. By analyzing archival HST data, we demonstrate that the quality of the LBT/PISCES color magnitude diagram is fully comparable with analogous space-based data. The smaller field of view is balanced by the shorter exposure time required to reach a similar photometric limit. We investigated the absolute age of M\,15 by means of two methods: i) by determining the age from the position of the main sequence turn-off; and ii) by the magnitude difference between the MSTO and the well-defined knee detected along the faint portion of the MS. We derive consistent values of the absolute age of M15, that is 12.9+-2.6 Gyr and 13.3+-1.1 Gyr, respectively.Comment: 13 pages, 8 figures, ApJ accepte

    Expanded Endoscopic Approach for Anterior Skull Base Tumors: Experience of a Multidisciplinary Skull Base Team

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    Abstract: The aim of this study is to describe the experience of a multidisciplinary skull base team with transnasal endoscopic surgery for anterior cranial base tumors. A retrospective chart review was conducted on patients who underwent an exclusive expanded transnasal approach to the anterior skull base in the period from December 2014 to November 2015. Data on patient demographics, tumor characteristics, surgical information, imaging, and postoperative complications were collected and analyzed. From a total of 120 patients with skull base diseases managed by the skull base team, 36 were admitted to this study. The overall complication rate in this series was 16.7%, gross total resection was achieved in 32 cases (88.9%) and postoperative CSF leakage occurred in 5 cases (13.9%). Our preliminary results confirm that an exclusive endoscopic transnasal approach to the anterior cranial base

    Ultrafast Electrochemical Self-Doping of Anodic Titanium Dioxide Nanotubes for Enhanced Electroanalytical and Photocatalytic Performance

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    This study explores an ultrarapid electrochemical self-doping procedure applied to anodic titanium dioxide (TiO2) nanotube arrays in an alkaline solution to boost their performance for electroanalytical and photocatalytic applications. The electrochemical self-doping process (i.e., the creation of surface Ti3+ states by applying a negative potential) is recently emerging as a simpler and cleaner way to improve the electronic properties of TiO2 compared to traditional chemical and high-temperature doping strategies. Here, self-doping was carried out through varying voltages and treatment times to identify the most performing materials without compromising their structural stability. Interestingly, cyclic voltammetry characterization revealed that undoped TiO2 shows negligible activity, whereas all self-doped materials demonstrate their suitability as electrode materials: an outstandingly short 10 s self-doping treatment leads to the highest electrochemical activity. The electrochemical detection of hydrogen peroxide was assessed as well, demonstrating a good sensitivity and a linear detection range of 3–200 µM. Additionally, the self-doped TiO2 nanotubes exhibited an enhanced photocatalytic activity compared to the untreated substrate: the degradation potential of methylene blue under UV light exposure increased by 25% in comparison to undoped materials. Overall, this study highlights the potential of ultrafast electrochemical self-doping to unleash and improve TiO2 nanotubes performances for electroanalytical and photocatalytic applications

    Conserving plant diversity in Europe: outcomes, criticisms and perspectives of the Habitats Directive application in Italy

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    Habitat Directive is the core strategy of nature conservation in Europe aiming at halting biodiversity loss. In this study the results of the third Italian assessment regarding the conservation status (CS) of plants listed in the Habitat Directive (Flora of community interest—FCI) was presented. Data was collected from several sources related to plant distribution, population data, habitats and pressures. Following the official European procedure, all parameters were evaluated and combined to give the CS of each taxon in each biogeographical region of presence. A comparison between the recent Italian IUCN and Reporting assessments was performed in order to evaluate the consistency between these two assessments. The official EU checklist comprises 113 Italian plant taxa, 107 of which were examined in this study. Our results showed a critical situation with only 34% of favourable CS, while 50% were unfavourable (40% inadequate plus 10% bad) and 16% unknown, in particular in the Mediterranean bioregion, where the unfavourable assessments reach the 65%. The results of the Report were consistent with those of the IUCN assessment, in which 41.9% of plants were threatened with extinction. This report highlighted some benefits and criticisms at national level, but it may have a wider significance. Although a general advance of knowledge, a great effort is needed to reach the Habitats Directive goals. Despite the limited resources, monitoring activities needs to be improved in order to close information gaps for several plants. A positive outcome was the development of a specific national project funded by the Italian Ministry of Environment, with the ambitious target to set future monitoring activities for FCI and optimize monitoring efforts

    Cost-effectiveness of intravitreal therapy with both anti-VEGF and Dexamethasone implant in patients with Diabetic Macular Edema

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    Purpose: The aim of this study was to evaluate the cost-effectiveness of intravitreal therapy (IVT) with both anti-VEGF and Dexamethasone implant in patients with Diabetic Macular Edema (DME) during two years’ follow-up. Methods: A retrospective review of 191 patients (382 eyes) with type I and II diabetes and DME was performed. Pre-IVT and final best correct visual acuity (BCVA), central macular thickness (CMT), intraocular pressure (IOP), number and type of IVT,number of examinations, and fluorescein angiography were assessed. Based on surgery procedure other than IVT, patients were divided into 5 groups. To avoid bias, we analysed only patients who had undergone cataract surgery before (group 1) or during enrolment (group 2). Results: 41 eyes from Group 1 and 48 eyes from group 2 were evaluated. Median BCVA ranged between 20/80 and 20/63 Snellen (P = 0.008) in Group 1 and from 20/63 to 20/40 Snellen (P = 0.0035) in Group 2, while improvement up to 1 Snellen line was observed in 58.5 and 68.75% of eyes in Group 1 and 2, respectively.In terms of median CMT, a statistically reduction (P = 0.0007) was found in Group 2 (-85 μm), whereas no statistical differences were found in Group 1. The two groups showed no statistically significant difference in median IOP. The estimated cost per eye was €7803 in Group 1 and €8988 Group 2, whereas the mean cost per patient was €15190 and €16580 in Group 1 and 2, respectively. Analysis between groups did not show any statistical difference in the considered parameters. Conclusions: In this study, despite the high treatment cost, vision improvement in DME patients undergoing IVT was disappointing. Our results emphasise the need for a better understanding of the cost-effectiveness of DME treatmen

    Advancements in combining electronic animal identification and augmented reality technologies in digital livestock farming

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    Modern livestock farm technologies allow operators to have access to a multitude of data thanks to the high number of mobile and fixed sensors available on both the livestock farming machinery and the animals. These data can be consulted via PC, tablet, and smartphone, which must be handheld by the operators, leading to an increase in the time needed for on-field activities. In this scenario, the use of augmented reality smart glasses could allow the visualization of data directly in the field, providing for a hands-free environment for the operator to work. Nevertheless, to visualize specific animal information, a connection between the augmented reality smart glasses and electronic animal identification is needed. Therefore, the main objective of this study was to develop and test a wearable framework, called SmartGlove that is able to link RFID animal tags and augmented reality smart glasses via a Bluetooth connection, allowing the visualization of specific animal data directly in the field. Moreover, another objective of the study was to compare different levels of augmented reality technologies (assisted reality vs. mixed reality) to assess the most suitable solution for livestock management scenarios. For this reason, the developed framework and the related augmented reality smart glasses applications were tested in the laboratory and in the field. Furthermore, the stakeholders’ point of view was analyzed using two standard questionnaires, the NASA-Task Load Index and the IBM-Post Study System Usability Questionnaire. The outcomes of the laboratory tests underlined promising results regarding the operating performances of the developed framework, showing no significant differences if compared to a commercial RFID reader. During the on-field trial, all the tested systems were capable of performing the task in a short time frame. Furthermore, the operators underlined the advantages of using the SmartGlove system coupled with the augmented reality smart glasses for the direct on-field visualization of animal data
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