769 research outputs found

    Observational constraints on the types of cosmic strings

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    This paper is aimed at setting observational limits to the number of cosmic strings (Nambu-Goto, Abelian-Higgs, semilocal) and other topological defects (textures). Radio maps of CMB anisotropy, provided by the space mission Planck for various frequencies, were filtered and then processed by the method of convolution with modified Haar functions (MHF) to search for cosmic string candidates. This method was designed to search for solitary strings, without additional assumptions about the presence of networks of such objects. The sensitivity of the MHF method is ÎŽT≈10ÎŒK\delta T \approx 10 \mu K in a background of ÎŽT≈100ÎŒK\delta T \approx 100 \mu K. The comparison of these with previously known results on search string network shows that strings can only be semilocal in an amount of 1Ă·51 \div 5, with the upper restriction on individual strings tension (linear density) of GÎŒ/c2≀7.36⋅10−7G\mu/c^2 \le 7.36 \cdot 10^{-7}. The texture model is also legal. There are no strings with GÎŒ/c2>7.36⋅10−7G\mu/c^2 > 7.36 \cdot 10^{-7}. However, comparison with the data for the search of non-Gaussian signals shows that the presence of several (up to 3) of Nambu-Goto strings is also possible. For GÎŒ/c2≀4.83⋅10−7G\mu/c^2 \le 4.83 \cdot 10^{-7} the MHF method is ineffective because of unverifiable spurious string candidates. Thus the existence of strings with tensions GÎŒ/c2≀4.83⋅10−7G\mu/c^2 \le 4.83 \cdot 10^{-7} is not prohibited but it is beyond the Planck data possibilities.Comment: 15 pages, 10 figures; accepted by the European Physical Journal

    HERV‐K(HML7) integrations in the human genome: Comprehensive characterization and comparative analysis in non‐human primates

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    Endogenous Retroviruses (ERVs) are ancient relics of infections that affected the primate germ line and constitute about 8% of our genome. Growing evidence indicates that ERVs had a major role in vertebrate evolution, being occasionally domesticated by the host physiology. In ad-dition, human ERV (HERV) expression is highly investigated for a possible pathological role, even if no clear associations have been reported yet. In fact, on the one side, the study of HERV expression in high‐throughput data is a powerful and promising tool to assess their actual dysregulation in diseased conditions; but, on the other side, the poor knowledge about the various HERV group genomic diversity and individual members somehow prevented the association between specific HERV loci and a given molecular mechanism of pathogenesis. The present study is focused on the HERV‐K(HML7) group that—differently from the other HERV‐K members—still remains poorly characterized. Starting from an initial identification performed with the software RetroTector, we collected 23 HML7 proviral insertions and about 160 HML7 solitary LTRs that were analyzed in terms of genomic distribution, revealing a significant enrichment in chromosome X and the frequent localization within human gene introns as well as in pericentromeric and centromeric regions. Phy-logenetic analyses showed that HML7 members form a monophyletic group, which based on age estimation and comparative localization in non‐human primates had its major diffusion between 20 and 30 million years ago. Structural characterization revealed that besides 3 complete HML7 pro-viruses, the other group members shared a highly defective structure that, however, still presents recognizable functional domains, making it worth further investigation in the human population to assess the presence of residual coding potential

    Weight Loss in Advanced Chronic Kidney Disease: Should We Consider Individualised, Qualitative, ad Libitum Diets? A Narrative Review and Case Study.

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    In advanced chronic kidney disease, obesity may bring a survival advantage, but many transplant centres demand weight loss before wait-listing for kidney graft. The case here described regards a 71-year-old man, with obesity-related glomerulopathy; referral data were: weight 110 kg, Body Mass Index (BMI) 37 kg/m2, serum creatinine (sCr) 5 mg/dL, estimated glomerular filtration rate (eGFR) 23 mL/min, blood urea nitrogen (BUN) 75 mg/dL, proteinuria 2.3 g/day. A moderately restricted, low-protein diet allowed reduction in BUN (45–55 mg/dL) and good metabolic and kidney function stability, with a weight increase of 6 kg. Therefore, he asked to be enrolled in a weight-loss program to be wait-listed (the two nearest transplant centres required a BMI below 30 or 35 kg/m2). Since previous low-calorie diets were not successful and he was against a surgical approach, we chose a qualitative, ad libitum coach-assisted diet, freely available in our unit. In the first phase, the diet is dissociated; he lost 16 kg in 2 months, without need for dialysis. In the second maintenance phase, in which foods are progressively combined, he lost 4 kg in 5 months, allowing wait-listing. Dialysis started one year later, and was followed by weight gain of about 5 kg. He resumed the maintenance diet, and his current body weight, 35 months after the start of the diet, is 94 kg, with a BMI of 31.7 kg/m2, without clinical or biochemical signs of malnutrition. This case suggests that our patients can benefit from the same options available to non-CKD (chronic kidney disease) individuals, provided that strict multidisciplinary surveillance is assured

    Evaluation of corneal distortion characteristics in different eyes using Scheimpflug camera device

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    Objective. To study the correlations between corneal distortion and morphological features in different kinds of eyes such as healthy ones (HE), ones previously undergone myopic PRK (PRKE), ones affected by keratoconus (KCE) and keratoconus eyes previously undergone corneal collagen crosslinking (CCCE). Materials and Methods. In this retrospective comparative study, a total of 106 HE of 106 patients, 58 PRKE of 58 patients, 33 KCE of 33 patients, 28 CCCE of 28 patients were included. A complete examination of all eyes was followed by tomographic (Pentacam, Oculus, Wetzlar, Germany) and biomechanical (Corvis ST, Oculus, Wetzlar, Germany) evaluation. Differences among Corvis ST (CST) parameters in the different groups have been analyzed. Linear regressions between central corneal thickness (CCT), intraocular pressure (IOP) and anterior corneal curvature measured with Simulated Keratometry (SK), versus corneal deformation parameters measured with Corvis ST in the different groups, have been run using SPSS software version 18.0. Results, HE showed a significant correlation between main curvature power of the cornea within the central 3 mm expressed in Diopters (KM) and 6 CST parameters; between CCT and 4 CST parameters and between IOP and 5 CST parameters. PRKE showed a significant correlation between KM and 3 CST parameters; between IOP and 4 CST parameters and none between CCT and CST parameters. KCE showed a significant correlation between SK and 3 CST parameters; between IOP and 3 CST parameters and none between CCT and CST parameters. CCCE showed a significant correlation between KM and 5 CST parameters; between CCT and 1 CST parameters and between IOP and 5 CST parameters. Discussion. Data of this study suggest that both corneal curvature and IOP could have a greater influence on the corneal deformation, compared to central corneal thickness (CCT). These results should be taken into account by further studies aiming to assess biomechanical corneal characteristics

    Tuning an Earthworm phase picker: some considerations on the pick_ew parameters

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    Although the Earthworm project started with the initial mission of replacing the old real time picker by Rex Allen, as developed by Jim Ellis [Allen, 1978; Allen, 1982; USGS et al., 2010], that picker is still in use in many networks. The name of the procedure that implements the Allen’s algorithm is pick_ew. Despite its long-lived use, configuring this picker still seems not so immediate and easy. We discuss here a few simple rules to define some of the numerous (18) parameters of pick_ew, interpreting their physical meaning

    Robust Classification via Support Vector Machines

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    Classification models are very sensitive to data uncertainty, and finding robust classifiers that are less sensitive to data uncertainty has raised great interest in the machine learning literature. This paper aims to construct robust Support Vector Machine (SVM) classifiers under feature data uncertainty via two probabilistic arguments. The first classifier, Single Perturbation (SP-SVM), reduces the local effect of data uncertainty with respect to one given feature and acts as a local test that could confirm or refute the presence of significant data uncertainty for that particular feature. The second classifier, Extreme Empirical Loss (EEL-SVM), aims to reduce the aggregate effect of data uncertainty with respect to all features, which is possible via a trade-off between the number of prediction model violations and the size of these violations. Both methodologies are computationally efficient and our extensive numerical investigation highlights the advantages and possible limitations of the two robust classifiers on synthetic and real-life data

    Headspace Volatile Composition of the Flowers of Caralluma europaea N.E.Br. (Apocynaceae)

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    The volatile constituents of the flowers of Caralluma (Apteranthes) europaea (Guss.) N.E. Br. (Apocynaceae - Asclepiadoideae) from Lampedusa Island were analyzed by headspace method. The analyses allowed the identification and quantification of 41 compounds. The main components were, among the monoterpenoids, terpinolene (23.3%), a-terpinene (19.1%) and linalool (18.4%), whereas, among the carbonylic compounds the major constituents were heptanal (2.0%), octanoic acid (2.4%) and hexanoic acid (1.7%). It is worth to mention the presence of a nitrogen containing compound, indole (0.8%) and of a sulphur containing compound, dimethylsulphide (t). The compounds found in the flowers of C. europea have been compared with data available in the literature as regard to their odor, presence in other sapromyiophilous taxa, possible role as semiochemicals, and presence in decaying organ matter. 89.3% of total constituents have been described in other sapromyiophilous taxa. Some of the compounds are present in several type of decaying organic matter (excrements, body in decomposition, and spoiled fish, etc). Several volatiles found in C. europea flowers are used as semiochemicals in Hymenoptera, Coleoptera, Diptera, Lepidoptera and other insects. Sixteen volatiles, accounting for 32.4% of the total constituents, are described as attractants of some Diptera families with a biology linked to decaying organic matters. Our data thus confirm that C. europea floral bouquet falls within the sapromyiophilous pollination syndrome

    MedNet status report

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    MedNet is a network of very broadband seismic stations installed in countries bordering the Mediterranean area. The project started in 1987, with a final goal of 12-15 stations and a spacing of about 1000 km between stations. It was motivated both by research interest and by seismic hazard monitoring. The network presently comprises 23 operating stations, all of them equipped with state of the art seismographic stations. Presently, fully automatic network functions include: - daily monitoring of state of health; - data recover after link failures; - triggered retrieval of event waveforms; - update of web pages (http://mednet.ingv.it) for events and station information.PublishedS. Fernando (SPAIN)1.1. TTC - Monitoraggio sismico del territorio nazionaleope

    Pediatric Injury Surveillance From Uncoded Emergency Department Admission Records in Italy: Machine Learning-Based Text-Mining Approach

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    Background: Unintentional injury is the leading cause of death in young children. Emergency department (ED) diagnoses are a useful source of information for injury epidemiological surveillance purposes. However, ED data collection systems often use free-text fields to report patient diagnoses. Machine learning techniques (MLTs) are powerful tools for automatic text classification. The MLT system is useful to improve injury surveillance by speeding up the manual free-text coding tasks of ED diagnoses. Objective: This research aims to develop a tool for automatic free-text classification of ED diagnoses to automatically identify injury cases. The automatic classification system also serves for epidemiological purposes to identify the burden of pediatric injuries in Padua, a large province in the Veneto region in the Northeast Italy. Methods: The study includes 283, 468 pediatric admissions between 2007 and 2018 to the Padova University Hospital ED, a large referral center in Northern Italy. Each record reports a diagnosis by free text. The records are standard tools for reporting patient diagnoses. An expert pediatrician manually classified a randomly extracted sample of approximately 40, 000 diagnoses. This study sample served as the gold standard to train an MLT classifier. After preprocessing, a document-term matrix was created. The machine learning classifiers, including decision tree, random forest, gradient boosting method (GBM), and support vector machine (SVM), were tuned by 4-fold cross-validation. The injury diagnoses were classified into 3 hierarchical classification tasks, as follows: injury versus noninjury (task A), intentional versus unintentional injury (task B), and type of unintentional injury (task C), according to the World Health Organization classification of injuries. Results: The SVM classifier achieved the highest performance accuracy (94.14%) in classifying injury versus noninjury cases (task A). The GBM method produced the best results (92% accuracy) for the unintentional and intentional injury classification task (task B). The highest accuracy for the unintentional injury subclassification (task C) was achieved by the SVM classifier. The SVM, random forest, and GBM algorithms performed similarly against the gold standard across different tasks. Conclusions: This study shows that MLTs are promising techniques for improving epidemiological surveillance, allowing for the automatic classification of pediatric ED free-text diagnoses. The MLTs revealed a suitable classification performance, especially for general injuries and intentional injury classification. This automatic classification could facilitate the epidemiological surveillance of pediatric injuries by also reducing the health professionals' efforts in manually classifying diagnoses for research purposes
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