9,465 research outputs found

    The Elephant Quantum Walk

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    We explore the impact of long-range memory on the properties of a family of quantum walks in a one-dimensional lattice and discrete time, which can be understood as the quantum version of the classical "Elephant Random Walk" non-Markovian process. This Elephant Quantum Walk is robustly superballistic with the standard deviation showing a constant exponent, σt3/2\sigma \propto t^{3/ 2} , whatever the quantum coin operator, on which the diffusion coefficient is dependent. On the one hand, this result indicates that contrarily to the classical case, the degree of superdiffusivity in quantum non- Markovian processes of this kind is mainly ruled by the extension of memory rather than other microscopic parameters that explicitly define the process. On the other hand, these parameters reflect on the diffusion coefficient.Comment: 4 figures, any comments is welcome. Accepted in PR

    Fertility preservation in ovarian tumours

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    A considerable number of patients with a cancer diagnosis are of childbearing age and have not satisfied their desire for a family. Despite ovarian cancer (OC) usually occurring in older patients, 3%–14% are diagnosed at a fertile age with the overall 5-year survival rate being 91.2% in women ≤44 years of age when it is found at 1A–B stage. In this scenario, testing the safety and the efficacy of fertility sparing strategies in OC patients is very important overall in terms of quality of life. Unfortunately, the lack of randomised trials to validate conservative approaches does not guarantee the safety of fertility preservation strategies. However, evidence-based data from descriptive series suggest that in selected cases, the preservation of the uterus and at least one part of the ovary does not lead to a high risk of relapse. This conservative surgery helps to maintain organ function, giving patients of childbearing age the possibility to preserve their fertility. We hereby analysed the main evidence from the international literature on this topic in order to highlight the selected criteria for conservative management of OC patients, including healthy BRCA mutations carriers

    Report on advances for pediatricians in 2018: allergy, cardiology, critical care, endocrinology, hereditary metabolic diseases, gastroenterology, infectious diseases, neonatology, nutrition, respiratory tract disorders and surgery.

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    This review reported notable advances in pediatrics that have been published in 2018. We have highlighted progresses in allergy, cardiology, critical care, endocrinology, hereditary metabolic diseases, gastroenterology, infectious diseases, neonatology, nutrition, respiratory tract disorders and surgery. Many studies have informed on epidemiologic observations. Promising outcomes in prevention, diagnosis and treatment have been reported. We think that advances realized in 2018 can now be utilized to ameliorate patient car

    Characterisation of AMS H35 HV-CMOS monolithic active pixel sensor prototypes for HEP applications

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    Monolithic active pixel sensors produced in High Voltage CMOS (HV-CMOS) technology are being considered for High Energy Physics applications due to the ease of production and the reduced costs. Such technology is especially appealing when large areas to be covered and material budget are concerned. This is the case of the outermost pixel layers of the future ATLAS tracking detector for the HL-LHC. For experiments at hadron colliders, radiation hardness is a key requirement which is not fulfilled by standard CMOS sensor designs that collect charge by diffusion. This issue has been addressed by depleted active pixel sensors in which electronics are embedded into a large deep implantation ensuring uniform charge collection by drift. Very first small prototypes of hybrid depleted active pixel sensors have already shown a radiation hardness compatible with the ATLAS requirements. Nevertheless, to compete with the present hybrid solutions a further reduction in costs achievable by a fully monolithic design is desirable. The H35DEMO is a large electrode full reticle demonstrator chip produced in AMS 350 nm HV-CMOS technology by the collaboration of Karlsruher Institut f\"ur Technologie (KIT), Institut de F\'isica d'Altes Energies (IFAE), University of Liverpool and University of Geneva. It includes two large monolithic pixel matrices which can be operated standalone. One of these two matrices has been characterised at beam test before and after irradiation with protons and neutrons. Results demonstrated the feasibility of producing radiation hard large area fully monolithic pixel sensors in HV-CMOS technology. H35DEMO chips with a substrate resistivity of 200Ω\Omega cm irradiated with neutrons showed a radiation hardness up to a fluence of 101510^{15}neq_{eq}cm2^{-2} with a hit efficiency of about 99% and a noise occupancy lower than 10610^{-6} hits in a LHC bunch crossing of 25ns at 150V

    Performance of the diamond active target prototype for the PADME experiment at the DAΦ\PhiNE BTF

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    The PADME experiment at the DAΦ\PhiNE Beam-Test Facility (BTF) is designed to search for the gauge boson of a new U(1)\rm U(1) interaction in the process e+^+eγ^-\rightarrow\gamma+A\rm A', using the intense positron beam hitting a light target. The A\rm A', usually referred as dark photon, is assumed to decay into invisible particles of a secluded sector and it can be observed by searching for an anomalous peak in the spectrum of the missing mass measured in events with a single photon in the final state. The measurement requires the determination of the 4-momentum of the recoil photon, performed by a homogeneous, highly segmented BGO crystals calorimeter. A significant improvement of the missing mass resolution is possible using an active target capable to determine the average position of the positron bunch with a resolution of less than 1 mm. This report presents the performance of a real size (2x2cm2)\rm (2x2 cm^2) PADME active target made of a thin (50 μ\mum) diamond sensor, with graphitic strips produced via laser irradiation on both sides. The measurements are based on data collected in a beam test at the BTF in November 2015.Comment: 7 pages, 10 figure

    Selected amino acid changes in HIV-1 subtype-C gp41 are associated with specific gp120(V3) signatures in the regulation of co-receptor usage

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    The majority of studies have characterized the tropism of HIV-1 subtype-B isolates, but little is known about the determinants of tropism in other subtypes. So, the goal of the present study was to genetically characterize the envelope of viral proteins in terms of co-receptor usage by analyzing 356 full-length env sequences derived from HIV-1 subtype-C infected individuals. The co-receptor usage of V3 sequences was inferred by using the Geno2Pheno and PSSM algorithms, and also analyzed to the "11/25 rule". All reported env sequences were also analyzed with regard to N-linked glycosylation sites, net charge and hydrophilicity, as well as the binomial correlation phi coefficient to assess covariation among gp120(V3) and gp41 signatures and the average linkage hierarchical agglomerative clustering were also performed. Among env sequences present in Los Alamos Database, 255 and 101 sequences predicted as CCR5 and CXCR4 were selected, respectively. The classical V3 signatures at positions 11 and 25, and other specific V3 and gp41 amino acid changes were found statistically associated with different co-receptor usage. Furthermore, several statistically significant associations between V3 and gp41 signatures were also observed. The dendrogram topology showed a cluster associated with CCR5-usage composed by five gp41 mutated positions, A22V, R133M, E136G, N140L, and N166Q that clustered with T2V(V3) and G24T(V3) (bootstrap=1). Conversely, a heterogeneous cluster with CXCR4-usage, involving S11GR(V3), 13-14insIG/LG(V3), P16RQ(V3), Q18KR(V3), F20ILV(V3), D25KRQ(V3), Q32KR(V3) along with A30T(gp41), S107N(gp41), D148E(gp41), A189S(gp41) was identified (bootstrap=0.86). Our results show that as observed for HIV-1 subtype-B, also in subtype-C specific and different gp41 and gp120V3 amino acid changes are associated individually or together with CXCR4 and/or CCR5 usage. These findings strengthen previous observations that determinants of tropism may also reside in the gp41 protein

    Anatomy of the AGN in NGC 5548: V. A clear view of the X-ray narrow emission lines

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    Context. Our consortium performed an extensive multi-wavelength campaign of the nearby Seyfert 1 galaxy NGC 5548 in 2013-14. The source appeared unusually heavily absorbed in the soft X-rays, and signatures of outflowing absorption were also present in the UV. He-like triplets of neon, oxygen and nitrogen, and radiative recombination continuum (RRC) features were found to dominate the soft X-ray spectrum due to the low continuum flux. Aims. Here we focus on characterising these narrow emission features using data obtained from the XMM-Newton RGS (770 ks stacked spectrum). Methods. We use SPEX for our initial analysis of these features. Self-consistent photoionisation models from Cloudy are then compared with the data to characterise the physical conditions of the emitting region. Results. Outflow velocity discrepancies within the O VII triplet lines can be explained if the X-ray narrow-line region (NLR) in NGC 5548 is absorbed by at least one of the six warm absorber components found by previous analyses. The RRCs allow us to directly calculate a temperature of the emitting gas of a few eV (104\sim10^{4} K), favouring photoionised conditions. We fit the data with a Cloudy model of log ξ=1.45±0.05\xi = 1.45 \pm 0.05 erg cm s1^{-1}, log NH=22.9±0.4N_H = 22.9 \pm 0.4 cm2^{-2} and log vturb=2.25±0.5_{turb} = 2.25 \pm 0.5 km s1^{-1} for the emitting gas; this is the first time the X-ray NLR gas in this source has been modelled so comprehensively. This allows us to estimate the distance from the central source to the illuminated face of the emitting clouds as 13.9±0.613.9 \pm 0.6 pc, consistent with previous work.Comment: Accepted by A&A, 15 pages, 6 figure

    TOWARDS BENZ[A]ANTHRACENE XENOME ELUCIDATION IN PLANTS AND GREEN MICROALGAE

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    In only 12,000 years the Homo sapiens sapiens has completely modified the face of the Earth. The human pressure on the atmosphere, water and soil has been accelerate from the industrial revolution from which chemicals and energy have been released in the environment. Therefore, chemical environmental pollution and world climate changes are two of the main concerns that modern human must deal. Among chemicals released in the ecosystem the polycyclic aromatic hydrocarbon (PAHs) have gathered significant environment concerns for their detrimental biological effects, toxicity, mutagenicity, and carcinogenicity. The distribution of PAHs in the three environment compartments is related to the number of fused benzene rings. Two or three benzene rings have been occurring in the atmosphere whereas 5 or more rings are largely bounds in the soil particles. Intermediate, 4-rings, such as benz(a)anthracene (B[a]A) are partitioned between air and soil. The molecular mechanism involved to degrade PAHs into less toxic compounds by bacteria and fungi in soil has been elucidated. On the other hands, the metabolism of PAHs in plant and microalgae remain unknown. Signalling, transport, biotransformation of PAHs to less toxic molecules and compartmentalization are the main steps involved for their detoxification in photosynthetic cell. The expression of genes involved in these xenobiotics detoxification steps constitutes the xenome. The final aim of this work is to determine the B[a]A xenome in plants of tomato and in microalgae. So far, we have assessed the ability of tomato plants to grow in vitro and take up the B[a]A. Tomato seedlings were transplanted to MS medium added with 50 and 100 μg g -1 B[a]A and cultivated for 30 days. The detection of B[a]A in shoots infer a translocation from roots to shoots. However, the content of the PAH in shoots was much lower than in the root apparatus indicating that B[a]A was translocated very little from roots to shoots. The identification of microalgae species B[a]A capable of growing in presence of has been performed on 14 different species belonging to the genera Chlorella, Scenedesmus, Chlamydomonas, Ankistrodesmus, Botriococcus and Selenastrum, with six different concentrations of B[a]A. Four microalgae species showed a growth inhibition percentage less than 50% in a medium containing 43.8 μM B[a]A. The capacity to degrade B[a]A and affect the photosynthetic pigment content has been evaluated in the identified microalgae grown for 21 days in the medium containing B[a]A. The four microalgae strains reached 90% B[a]A degradation. Then, in silico analysis was carried out on C. reinhardtii proteome to identify potential laccase involved in the degradation process. Finally, the response of intracellular and extracellular activity in the absence and presence of the B[a]A was analysed by ABTS and 2,6-DMP assays
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