12,250 research outputs found
Eco-friendly gas mixtures for Resistive Plate Chambers based on Tetrafluoropropene and Helium
Due to the recent restrictions deriving from the application of the Kyoto
protocol, the main components of the gas mixtures presently used in the
Resistive Plate Chambers systems of the LHC experiments will be most probably
phased out of production in the coming years. Identifying possible replacements
with the adequate characteristics requires an intense R&D, which was recently
started, also in collaborations across the various experiments. Possible
candidates have been proposed and are thoroughly investigated. Some tests on
one of the most promising candidate - HFO-1234ze, an allotropic form of
tetrafluoropropane- have already been reported. Here an innovative approach,
based on the use of Helium, to solve the problems related to the too elevate
operating voltage of HFO-1234ze based gas mixtures, is discussed and the
relative first results are shown.Comment: 9 pages, 6 figures, 1 tabl
Application Design and Engagement Strategy of a Game with a Purpose for Climate Change Awareness
The Climate Challenge is an online application in the tradition of games with a purpose that combines practical steps to reduce carbon footprint with predictive tasks to estimate future climate-related conditions. As part of the Collective Awareness Platform, the application aims to increase environmental literacy and motivate users to adopt more sustainable lifestyles. It has been deployed in conjunction with the Media Watch on Climate Change, a publicly available knowledge aggregator and visual analytics system for exploring environmental content from multiple online sources. This paper presents the motivation and goals of the Climate Challenge from an interdisciplinary perspective, outlines the application design including the types of tasks built into the application, discusses incentive mechanisms, and analyses the pursued user engagement strategies
Modified POF Sensor for Gaseous Hydrogen Fluoride Monitoring in the Presence of Ionizing Radiations
This paper describes the development of a sensor designed to detect low concentrations of hydrogen fluoride (HF) in gas mixtures. The sensor employs a plastic optical fiber (POF) covered with a thin layer of glass- like material. HF attacks the glass and alters the fiber transmission capability so that the detection simply requires a LED and a photodiode. The coated POF is obtained by means of low-pressure plasma-enhanced chemical vapor deposition that allows the glass-like film to be deposited at low temperature without damaging the fiber core. The developed sensor will be installed in the recirculation gas system of the resistive plate chamber muon detector of the Compact Muon Solenoid experiment at the Large Hadron Collider accelerator of the European Organization for Nuclear Research (CERN
Fiber Bragg Grating sensors for deformation monitoring of GEM foils in HEP detectors
Fiber Bragg Grating (FBG) sensors have been so far mainly used in high energy
physics (HEP) as high precision positioning and re-positioning sensors and as
low cost, easy to mount, radiation hard and low space- consuming temperature
and humidity devices. FBGs are also commonly used for very precise strain
measurements. In this work we present a novel use of FBGs as flatness and
mechanical tensioning sensors applied to the wide Gas Electron Multiplier (GEM)
foils of the GE1/1 chambers of the Compact Muon Solenoid (CMS) experiment at
Large Hadron Collider (LHC) of CERN. A network of FBG sensors has been used to
determine the optimal mechanical tension applied and to characterize the
mechanical stress applied to the foils. The preliminary results of the test
performed on a full size GE1/1 final prototype and possible future developments
will be discussed.Comment: Four pages, seven figures. Presented by Michele Caponero at IWASI
2015, Gallipoli (Italy
A Support Vector Machine for the Discrimination of MicroRNA Precursors from Other Genomic Hairpin Structures
Motivation: MicroRNAs (miRNAs) are endogenous, small (~ 20 nt), single-stranded, non-coding RNAs (ncRNAs) that result from the nuclear and cytoplasmic processing of transcribed precursor hairpin structures. They are increasingly recognized as playing crucial roles as post-transcriptional antisense regulators of gene expression through regulation of mRNA stability or translational efficiency. miRNAs, first reported in Caenorhabditis elegans, have been identified in the genomes of most higher organisms, including worms, flies, plants, mammals and recently in viruses.
Functional studies have shown that miRNAs play important roles in processes such as, cell proliferation, fat metabolism, apoptosis, neuronal cell fate, insulin secretion, haematopoietic differentiation and developmental regulation.
The detection of homologs of known miRNAs through comparative genomic approaches has proved relatively tractable. However, the ab-initio prediction of miRNA precursors through computational methods poses several additional difficulties, not least the fact that not all thermodynamically plausible transcribed hairpins are processed to yield mature miRNAs. It has not until now been possible to identify conserved sequence or structural elements that define consensus recognition elements for the enzymes that process miRNA precursors.
In the light of these observations we wished to develop and improve methods for the discrimination of true miRNA precursor hairpins from spurious hairpins
Methods: We have developed a SVM (Support Vector Machine) that considers up to 74 features associated with the primary and secondary structures and thermodynamic characteristics of candidate hairpin structures. We use a standard heuristic approach to optimize combinations of features used and train the SVM with sets of characterized hairpin miRNA precursors and known non-miRNA hairpins.
Results: Our SVM shows highly promising results in the discrimination of true miRNA precursors from \u201cspurious\u201d hairpins (typically around 95% sensitivity) in various species. In particular, our levels of false positive predictions appear to be low relative to comparable methods
Towards an integrated pipeline for the in-silico prediction of plant microRNAs and their precursors
MicroRNAs (miRNAs) are endogenous, small (~ 20 nt), single-stranded, non-coding RNAs that result from the processing of transcribed precursor hairpin structures. They are increasingly recognized as playing crucial roles as post-transcriptional antisense regulators of gene expression through regulation of mRNA stability or translational efficiency.
The detection of homologs of known miRNAs through comparative genomic approaches has proved relatively tractable. However, the ab-initio prediction of potentially lineage-specific miRNA precursors through computational methods poses several additional difficulties, not least the fact that not all thermodynamically plausible transcribed hairpins are processed to yield mature miRNAs.
We have developed a Support Vector Machine that considers up to 78 features associated with the primary and secondary structures and thermodynamic characteristics of candidate hairpin structures. Our SVM is highly specific in the discrimination of true miRNA precursors from âspuriousâ hairpins with levels of false positive predictions that are low relative to comparable methods. We also show how our SVM functions as part of an in-silico pipeline for the prediction of novel miRNA precursors in plant genomes
Properties of potential eco-friendly gas replacements for particle detectors in high-energy physics
Gas detectors for elementary particles require F-based gases for optimal performance.
Recent regulations demand the use of environmentally unfriendly F-based gases to be limited or
banned. This work studies properties of potential eco-friendly gas replacements by computing the
physical and chemical parameters relevant for use as detector media, and suggests candidates to be
considered for experimental investigation
Properties of potential eco-friendly gas replacements for particle detectors in high-energy physics
Modern gas detectors for detection of particles require F-based gases for
optimal performance. Recent regulations demand the use of environmentally
unfriendly F-based gases to be limited or banned. This review studies
properties of potential eco-friendly gas candidate replacements.Comment: 38 pages, 9 figures, 8 tables. To be submitted to Journal of
Instrumentatio
Candidate eco-friendly gas mixtures for MPGDs
Modern gas detectors for detection of particles require F-based gases for optimal performance.Recent regulations demand the use of environmentally unfriendly F-based gases t o be limited or banned. This review studies properties of potential eco-friendly gas candidate replacements
Nero Siciliano pig: effect of the diet on meat quality
In the context of a typical breeding system for the autochthonous pig races, the effects of the traditional diet (grain cereals, legumes and agro-industrial by-product) and of a commercial diet (pellets) on the meat quality of Nero Siciliano pig were studied. Thirty animals, 16 castrated males and 14 females, were divided into two groups of 15 each one homogeneous for live weight (32.47±1.74 kg), sex (8 males and 7 females) and age (2 months), called "Traditional" (TRA) and "Experimental" (EXPE). Pigs of "TRA" group were fed with barleycorn (2 kg/head/day) and citrus pulp (1 kg/head/day) whereas, those of "EXPE" group received 1.3 kg/head/day of a pelletted complete feed (Dry Matter: 87.5%, on a DM basis: 18.29% Crude Protein, 3.43% Ether Extract, 6.06% Crude Fiber, 7.43% Ash) formulated to be isoenergetic and isonitrogenous with the Traditional diet. The trial lasted 93 days, preceded by a 15day adaptation period. After the slaughter (FLW: EXPE 67.4kg vs. TRA 61.69 kg; P>0.05 and FCR: EXPE 3.71 kg/kg vs. TRA 6.65 kg/kg; P<0.001), chemical and fatty acid composition of the Longissimus lumborum muscle were determined as well as the acidic composition of the lard removed by the backfat. On the basis of the fatty acid profile, the quality indices were calculated. The oxidative stability (TBARs) of the intramuscular lipid was determined at 1, 3, 5 days after slaughtering. Data were subjected to ANOVA. Protein (EXPE 23.01 g/100g vs. TRA 23.17 g/100g) and lipid (EXPE 3.12 g/100g vs. TRA 2.69 g/100g) content of the muscle was unaffected by the diet whereas, moisture (EXPE 72.52 g/100g vs. TRA 73.072 g/100g) and ash (EXPE 1.01 g/100g vs. TRA 1.08 g/100g) levels showed significant (P<0.05) differences. As regards fatty acid composition of the meat, significant differences were observed for the total SFAs (EXPE 41.42% vs. TRA 38.95%, P<0.01) and PUFAs (EXPE 9.05% vs. TRA 12.11%, P<0.05) in particular for the n3 series (EXPE 0.79% vs. TRA 1.40%, P<0.05) and for the n6 series PUFAs (EXPE 8.11% vs. TRA 10.49%, P<0.05). Fatty acid composition of the lard showed significant (P<0.05) differences for MUFAs (EXPE 47.63% vs. TRA 49.11%) and PUFAs (EXPE 11.38% vs. TRA 10.01%); in particular significant differences for the n3 series (EXPE 0.77% vs. TRA 0.94%, P<0.05) and for the n6 series PUFAs (EXPE 10.62% vs. TRA 9.08%, P<0.01) were reported. The different distribution of the fatty acid classes in the meat and in the lard could be due to: i) the different acidic composition of the feeds (pellet vs. barleycorn + citrus pulp), ii) the different destinations of the plasmatic fatty acids during their metabolic cycle (constituents of adipose tissue, of tryglicerides, of membranes phospholipids). The quality indices have shown significant (P<0.001) differences only in the Longissimus lumborum muscle, with the highest values for the Atherogenic (EXPE 0.49% vs. TRA 0.42%,) and for the Thrombogenic indices (EXPE 1.11% vs. TRA 0.91%) in the EXPE group. No significant difference was observed for the oxidative stability of the muscle during the storage. Data show the importance to study specific diets for Nero Siciliano pig in relation to the destination of meat. Research supported by MIUR, PRIN-2003 ("Nero Siciliano pig breeding: evaluation of its production", Prof
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