Avalanche criticality in the martensitic transition of Cu67.64Zn16.71Al15.65 shape-memory alloy: a calorimetric and acoustic emission study

The first-order diffusionless structural transition in Cu67.64Zn16.71Al15.65 is characterized by jerky propagation of phase fronts related to the appearance of avalanches. In this paper, we describe a full analysis of this avalanche behavior using calorimetric heat-flux measurements and acoustic emission measurements. Two different propagation modes, namely, smooth front propagation and jerky avalanches, were observed in extremely slow measurements with heating and cooling rates as low as a few 10−3 K/h. Avalanches show criticality where each avalanche leads to a spike in the heat flux. Their statistical analysis leads to a power law [P(E)∼E−ε, where P(E)dE is the probability to observe an avalanche with energy E in an interval between E and E+dE] with an energy exponent of ε=2.15±0.15 in excellent agreement with the results of acoustic emission measurements. Avalanches appear to be more common for heating rates faster than 5×10−3 K/h whereas smooth front propagation occurs in all calorimetric measurements and (almost) exclusively for slower heating rates. Repeated cooling runs were taken after a waiting time of 1 month (and an intermediate heating run). Correlations between the avalanche sequences of the two cooling runs were found for the strongest avalanche peaks but not for the full sequence of avalanches. The memory effect is hence limited to strong avalanches

Performance evaluation for 68Ga and 18F of the ARGUS small-animal PET scanner based on the NEMA NU-4 standard

Proceeding of: 2010 IEEE Nuclear Science Symposium, Medical Imaging Conference and 17th Room Temperature Semiconductor Detector Workshop (IEEE), Knoxville, Tennessee, USA, October 30 - November 6, 201068Ga is one of the non-conventional nuclides that are being used in preclinical imaging. One disadvantage of 68Ga versus 18F is its larger positron range, which deteriorates the effective spatial resolution and the overall image quality. In this work we present a performance evaluation of the ARGUS smallanimal positron emission tomography (PET) scanner for two positron emitters, 68Ga and 18F. These experiments followed the procedure based on the National Electrical Manufacturers Association (NEMA) NU 4-2008 standard. We show how the use of 68Ga may affect the NEMA performance of the system in terms of image quality and spatial resolution. The recovery coefficients (RC) measured in the image-quality phantom ranged from 0.17 to 0.72 for 68Ga and from 0.28 to 0.92 for 18F, using iterative image reconstruction methods and applying all corrections. Under the same conditions the image noise (%STD) in a uniform region was 17.0% for 68Ga and 15.1% for 18F. The respective spillover ratios (SOR) were 0.13 and 0.09 in air, and 0.21 and 0.12 in water. Attenuation correction yielded an improvement of the SOR close to 50% for both radionuclides in the air-filled region. This work evaluates the image reconstruction methods and corrections available in the ARGUS PET for 68Ga and 18F to assess the influence of their physical properties on the NEMA parameters.Publicad

Detection system of magnetic nanoparticles in biological tissues by Magnetoencephalography

Magnetic nanoparticles are useful for a wide range of applications from data storage to medical imaging. Their unique features (controllable size in the nanoscale range, possibility to be coated with biological molecules, response to the application of a magnetic field...) make the development of a variety of medical applications possible, both for diagnosis and therapy [1-3]. On the other hand, Magnetoencephalography (MEG) is a non-invasive functional imaging technique that enables the description of the temporal and spatial patterns of brain activity in resting conditions or related to different basic cognitive processes, by detecting the weak magnetic fields generated by currents in the neurons [4,5]. The detection of the weak magnetic fields depends on gradiometer detection coils coupled to a superconducting quantum interference device (SQUID). However, MEG systems are not currently being used for the detection of MNPs in biological tissues. A system to newly detect Magnetic Nanoparticles (MNPs) in the brain and in biological tissues will be described. The method uses a commercial Magnetoencephalograph (MEG) and opens new possibilities to extend the use of MEG systems to new applications for both diagnosis and therapy of medical diseases, different from its common use in neurological diagnosis. To test the validity of the system, in this work, we will show its ability to detect MNPs in biological tissues and their possible use in diagnosis of cerebral brain microinjurie

An internet-based intervention for depression in primary care in Spain: A randomized controlled trial

Background: Depression is the most prevalent cause of illness-induced disability worldwide. Face-to-face psychotherapeutic interventions for depression can be challenging, so there is a need for other alternatives that allow these interventions to be offered. One feasible alternative is Internet-based psychological interventions. This is the first randomized controlled trial (RCT) on the effectiveness of an Internet-based intervention on depression in primary health care in Spain. Objective: Our aim was to compare the effectiveness of a low-intensity therapist-guided (LITG) Internet-based program and a completely self-guided (CSG) Internet-based program with improved treatment as usual (iTAU) care for depression. Methods: Multicenter, three-arm, parallel, RCT design, carried out between November 2012 and January 2014, with a follow-up of 15 months. In total, 296 adults from primary care settings in four Spanish regions, with mild or moderate major depression, were randomized to LITG (n=96), CSG (n=98), or iTAU (n=102). Research completers at follow-up were 63.5%. The intervention was Smiling is Fun, an Internet program based on cognitive behavioral therapy. All patients received iTAU by their general practitioners. Moreover, LITG received Smiling is Fun and the possibility of psychotherapeutic support on request by email, whereas CSG received only Smiling is Fun. The main outcome was the Beck Depression Inventory-II at 3 months from baseline. Mixed-effects multilevel analysis for repeated measures were undertaken. Results: There was no benefit for either CSG (B coefficient=-1.15; P=.444)] or LITG (B=-0.71; P=.634)] compared to iTAU, at 3 months. There were differences at 6 months iTAU vs CSG (B=-4.22; P=.007); iTAU vs LITG (B=-4.34; P=.005)] and 15 months iTAU vs CSG (B=-5.10; P=.001); iTAU vs LITG (B=-4.62; P=.002)]. There were no differences between CSG and LITG at any time. Adjusted and intention-to-treat models confirmed these findings. Conclusions: An Internet-based intervention for depression combined with iTAU conferred a benefit over iTAU alone in the Spanish primary health care system

Miniatures from domestic contexts in Iron age Iberia

This article reviews a set of miniatures from domestic contexts in Iron Age eastern Iberia, and interprets them in terms of their role in forging social personae. After an introduction to the historical case under consideration, the miniatures are described in terms of their typology and their contexts of provenance are outlined. Though not abundant, they tend to occur in central places in the landscape; specifically, they are often found in houses of the powerful. The vast majority are miniatures of pottery and tools, though some miniature weapons are recorded. We contend that these objects were used as a means of enculturation and for the learning of values and norms. It is no coincidence that they emerge in the archaeological record of Iron Age Iberia at the same time as the rise of a social structure based on hereditary power

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H →γ γ, H → Z Z∗ →4l and H →W W∗ →lνlν. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV, corresponding to an integrated luminosity of about 25 fb−1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson

Standalone vertex finding in the ATLAS muon spectrometer

A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011

Measurement of the top quark pair cross section with ATLAS in pp collisions at √s=7 TeV using final states with an electron or a muon and a hadronically decaying τ lepton

A measurement of the cross section of top quark pair production in proton-proton collisions recorded with the ATLAS detector at the Large Hadron Collider at a centre-of-mass energy of 7 TeV is reported. The data sample used corresponds to an integrated luminosity of 2.05 fb -1. Events with an isolated electron or muon and a τ lepton decaying hadronically are used. In addition, a large missing transverse momentum and two or more energetic jets are required. At least one of the jets must be identified as originating from a b quark. The measured cross section, σtt-=186±13(stat.)±20(syst.)±7(lumi.) pb, is in good agreement with the Standard Model prediction

Measurement of the top quark-pair production cross section with ATLAS in pp collisions at \sqrt{s}=7\TeV

A measurement of the production cross-section for top quark pairs(\ttbar) in $pp$ collisions at \sqrt{s}=7 \TeV is presented using data recorded with the ATLAS detector at the Large Hadron Collider. Events are selected in two different topologies: single lepton (electron $e$ or muon $\mu$) with large missing transverse energy and at least four jets, and dilepton ($ee$, $\mu\mu$ or $e\mu$) with large missing transverse energy and at least two jets. In a data sample of 2.9 pb-1, 37 candidate events are observed in the single-lepton topology and 9 events in the dilepton topology. The corresponding expected backgrounds from non-\ttbar Standard Model processes are estimated using data-driven methods and determined to be $12.2 \pm 3.9$ events and $2.5 \pm 0.6$ events, respectively. The kinematic properties of the selected events are consistent with SM \ttbar production. The inclusive top quark pair production cross-section is measured to be \sigmattbar=145 \pm 31 ^{+42}_{-27} pb where the first uncertainty is statistical and the second systematic. The measurement agrees with perturbative QCD calculations.Comment: 30 pages plus author list (50 pages total), 9 figures, 11 tables, CERN-PH number and final journal adde