12,084 research outputs found
NA60 Status Report
This report shortly summarizes the main results obtained from the analysis of the NA60 data during 2008, perspectives for the analysis activity during 2009 and the requests to CERN following from them. In addition, renewd interest is expressed for a possible continuation of NA60, including future running at lower SPS energies
A device to characterize optical fibres
ATLAS is a general purpose experiment approved for the LHC collider at CERN.
An important component of the detector is the central hadronic calorimeter; for
its construction more than 600,000 Wave Length Shifting (WLS) fibres
(corresponding to a total length of 1,120 Km) have been used.
We have built and put into operation a dedicated instrument for the
measurement of light yield and attenuation length over groups of 20 fibres at a
time.
The overall accuracy achieved in the measurement of light yield
(attenuation length) is 1.5% (3%).
We also report the results obtained using this method in the quality control
of a large sample of fibres.Comment: 17 pages 20 figeres submitted to NIM journa
Irritable bowel syndrome and gluten-related disorders
Background: Irritable bowel syndrome (IBS) is frequently associated with celiac disease (CD) and nonceliac gluten/wheat sensitivity (NCGS/NCWS), but epidemiological and pathophysiological aspects are still unclear. Furthermore, a gluten-free diet (GFD) can positively influence IBS symptoms. Methods: A comprehensive online search for IBS related to CD, NCGS and GFD was made using the Pubmed, Medline and Cochrane databases. Results: Although a systematic screening for CD in IBS is not recommended, CD prevalence can be increased in diarrhea-predominant IBS patients. On the other hand, IBS symptoms can be persistent in treated CD patients, and their prevalence tends to decrease on a GFD. IBS symptoms may overlap and be similar to those associated to nonceliac gluten and/or wheat sensitivity. Increased gut permeability could explain the gluten/wheat effects in IBS patients. Finally, a GFD could improve symptoms in a subgroup of IBS patients. Conclusions: The possible interplay between IBS and gluten-related disorders represents a scientifically and clinically challenging issue. Further studies are needed to confirm these data and better clarify the involved pathophysiological mechanisms
Fasi finali e riutilizzo di etĂ storica nel Nuraghe Cuccurada di Mogoro (OR)
Nel sito archeologico in località Cuccurada, in territorio comunale di Mogoro, le ricerche hanno evidenziato un insediamento pluristratificato, con fasi di occupazione del Neolitico recente (cultura di Ozieri), dell’Eneolitico (cultura di Monte Claro) e delle Età del Bronzo e del Ferro, con un riutilizzo dell’area in epoca romana e medievale. Il complesso è già abbastanza noto in letteratura, ma ancora parzialmente inedito per quanto riguarda i materiali e i dati di scavo. Nel presente contributo si vuole presentare nel dettaglio le diverse fasi di occupazione del sito, soprattutto in relazione ai momenti finali della frequentazione protostorica (Bronzo Finale/I Ferro) ed alla rioccupazione del complesso in età romana e medievale.In the archaeological site of Cuccurada, in the territory of Mogoro, the researches have evidenced a pluristratified settlement, with phases of occupation of the recent Neolithic (culture of Ozieri), of the Eneolithic age (culture of Monte Claro) and of the Bronze and Iron Ages, with a re-use of the area in roman and medieval period. The complex is already enough famous in literature, but still partially unknown regarding the materials and the excavation data. In the present work we want to present in detail the different occupation phases of the site, especially in relationship to the final moments of the proto-historic frequentation (Final Bronze/I Iron Age) and to the last re-use of the complex in Roman and medieval age
Comparative genome-wide analysis of repetitive DNA in the genus Populus L.
Genome skimming was performed, using Illumina sequence reads, in order to obtain a detailed comparative picture of the repetitive component of the genome of Populus species. Read sets of seven Populus and two Salix species (as outgroups) were subjected to clustering using RepeatExplorer (Novák et al. BMC Bioinformatics 11:378 2010). The repetitive portion of the genome ranged from 33.8 in Populus nigra to 46.5% in Populus tremuloides. The large majority of repetitive sequences were long terminal repeat-retrotransposons. Gypsy elements were over-represented compared to Copia ones, with a mean ratio Gypsy to Copia of 6.7:1. Satellite DNAs showed a mean genome proportion of 2.2%. DNA transposons and ribosomal DNA showed genome proportions of 1.8 and 1.9%, respectively. The other repeat types accounted for less of 1% each. Long terminal repeat-retrotransposons were further characterized, identifying the lineage to which they belong and studying the proliferation times of each lineage in the different species. The most abundant lineage was Athila, which showed large differences among species. Concerning Copia lineages, similar transpositional profiles were observed among all the analysed species; by contrast, differences in transpositional peaks of Gypsy lineages were found. The genome proportions of repeats were compared in the seven species, and a phylogenetic tree was built, showing species separation according to the botanical section to which the species belongs, although significant differences could be found within sections, possibly related to the different geographical origin of the species. Overall, the data indicate that the repetitive component of the genome in the poplar genus is still rapidly evolving
Popularity prediction of instagram posts
Predicting the popularity of posts on social networks has taken on significant importance in recent years, and several social media management tools now offer solutions to improve and optimize the quality of published content and to enhance the attractiveness of companies and organizations. Scientific research has recently moved in this direction, with the aim of exploiting advanced techniques such as machine learning, deep learning, natural language processing, etc., to support such tools. In light of the above, in this work we aim to address the challenge of predicting the popularity of a future post on Instagram, by defining the problem as a classification task and by proposing an original approach based on Gradient Boosting and feature engineering, which led us to promising experimental results. The proposed approach exploits big data technologies for scalability and efficiency, and it is general enough to be applied to other social media as well
Gastroparesis: New insights into an old disease
Gastroparesis (Gp) is a chronic disease characterized by a delayed gastric emptying in the absence of mechanical obstruction. Although this condition has been reported in the literature since the mid-1900s, only recently has there been renewed clinical and scientific interest in this disease, which has a potentially great impact on the quality of life. The aim of this review is to explore the pathophysiological, diagnostic and therapeutical aspects of Gp according to the most recent evidence. A comprehensive online search for Gp was carried out using MEDLINE and EMBASE. Gp is the result of neuromuscular abnormalities of the gastric motor function. There is evidence that patients with idiopathic and diabetic Gp may display a reduction in nitrergic inhibitory neurons and in interstitial cells of Cajal and/or telocytes. As regards diagnostic approach, 99-Technetium scintigraphy is currently considered to be the gold standard for Gp. Its limits are a lack of standardization and a mild risk of radiation exposure. The C13 breath testing is a valid and safe alternative method. 13C acid octanoic and the 13C Spirulina platensis recently approved by the Food and Drug Administration are the most commonly used diagnostic kits. The wireless motility capsule is a promising technique, but its use is limited by costs and scarce availability in many countries. Finally, therapeutic strategies are related to the clinical severity of Gp. In mild and moderate Gp, dietary modification and prokinetic agents are generally sufficient. Metoclopramide is the only drug approved by the Food and Drug Administration for Gp. However, other older and new prokinetics and antiemetics can be considered. As a second-line therapy, tricyclic antidepressants and cannabinoids have been proposed. In severe cases the normal nutritional approach can be compromised and artificial nutrition may be needed. In drug-unresponsive Gp patients some alternative strategies (endoscopic, electric stimulation or surgery) are available
Distribution of HLA-DPB1, -DQB1 -DQA1 alleles among Sardinian celiac patients.
The Sardinian population in many aspects differs from other Caucasoid populations, particularly for its degree of homogeneity. For this reason we have studied 50 adult Sardinian patients with celiac disease (CD) and 50 control healthy Sardinian individuals by RFLP analysis and by extensive oligotyping for 17 HLA-DPB 1, 8-DQB I and 9-DQA 1 alleles, and established their -DPB I alleles and -DQB I -DQA I genotypes. The heterodimer HLA-DQB 1 *0201/-DQA 1 *0501, present in 96% of our patients, is strongly associated with CD susceptibility, confirming published reports. On the other hand we found in 11 of 50 probands (22%) the presence of the allele -DQB 1 *05021 DQA1*0102. This genotype is extremely rare in other Caucasian populations and appears to confer limited protection in CD Sardinian patients
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