2,321 research outputs found

    Experimental estimation of the dimension of classical and quantum systems

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    An overwhelming majority of experiments in classical and quantum physics make a priori assumptions about the dimension of the system under consideration. However, would it be possible to assess the dimension of a completely unknown system only from the results of measurements performed on it, without any extra assumption? The concept of a dimension witness answers this question, as it allows one to bound the dimension of an unknown classical or quantum system in a device-independent manner, that is, only from the statistics of measurements performed on it. Here, we report on the experimental demonstration of dimension witnesses in a prepare and measure scenario. We use pairs of photons entangled in both polarization and orbital angular momentum to generate ensembles of classical and quantum states of dimensions up to 4. We then use a dimension witness to certify their dimensionality as well as their quantum nature. Our results open new avenues for the device-independent estimation of unknown quantum systems and for applications in quantum information science.Comment: See also similar, independent and jointly submitted work of J. Ahrens et al., quant-ph/1111.127

    Filamin C variants are associated with a distinctive clinical and immunohistochemical arrhythmogenic cardiomyopathy phenotype.

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    BACKGROUND: Pathogenic variants in the filamin C (FLNC) gene are associated with inherited cardiomyopathies including dilated cardiomyopathy with an arrhythmogenic phenotype. We evaluated FLNC variants in arrhythmogenic cardiomyopathy (ACM) and investigated the disease mechanism at a molecular level. METHODS: 120 gene-elusive ACM patients who fulfilled diagnostic criteria for arrhythmogenic right ventricular cardiomyopathy (ARVC) were screened by whole exome sequencing. Fixed cardiac tissue from FLNC variant carriers who had died suddenly was investigated by histology and immunohistochemistry. RESULTS: Novel or rare FLNC variants, four null and five variants of unknown significance, were identified in nine ACM probands (7.5%). In FLNC null variant carriers (including family members, n = 16) Task Force diagnostic electrocardiogram repolarization/depolarization abnormalities were uncommon (19%), echocardiography was normal in 69%, while 56% had >500 ventricular ectopics/24 h or ventricular tachycardia on Holter and 67% had late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging (CMRI). Ten gene positive individuals (63%) had abnormalities on ECG or CMRI that are not included in the current diagnostic criteria for ARVC. Immunohistochemistry showed altered key protein distribution, distinctive from that observed in ARVC, predominantly in the left ventricle. CONCLUSIONS: ACM associated with FLNC variants presents with a distinctive phenotype characterized by Holter arrhythmia and LGE on CMRI with unremarkable ECG and echocardiographic findings. Clinical presentation in asymptomatic mutation carriers at risk of sudden death may include abnormalities which are currently non-diagnostic for ARVC. At the molecular level, the pathogenic mechanism related to FLNC appears different to classic forms of ARVC caused by desmosomal mutations

    Tumour heterogeneity in glioblastoma assessed by MRI texture analysis: a potential marker of survival

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    Objective: The main objective of this retrospective work was the study of three-dimensional (3D) heterogeneity measures of post-contrast pre-operative MR images acquired with T1 weighted sequences of patients with glioblastoma (GBM) as predictors of clinical outcome. Methods: 79 patients from 3 hospitals were included in the study. 16 3D textural heterogeneity measures were computed including run-length matrix (RLM) features (regional heterogeneity) and co-occurrence matrix (CM) features (local heterogeneity). The significance of the results was studied using Kaplan?Meier curves and Cox proportional hazards analysis. Correlation between the variables of the study was assessed using the Spearman?s correlation coefficient. Results: Kaplan?Meyer survival analysis showed that 4 of the 11 RLM features and 4 of the 5 CM features considered were robust predictors of survival. The median survival differences in the most significant cases were of over 6 months. Conclusion: Heterogeneity measures computed on the post-contrast pre-operative T1 weighted MR images of patients with GBM are predictors of survival. Advances in knowledge: Texture analysis to assess tumour heterogeneity has been widely studied. However, most works develop a two-dimensional analysis, focusing only on one MRI slice to state tumour heterogeneity. The study of fully 3D heterogeneity textural features as predictors of clinical outcome is more robust and is not dependent on the selected slice of the tumour

    Risk of miscarriage after chorionic villus sampling.

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    OBJECTIVE: To estimate the risk of miscarriage associated to chorionic villus sampling (CVS). METHODS: This was a retrospective cohort study performed in eight fetal-medicine units in Spain, Belgium and Bulgaria. Two populations were included: first, all singleton pregnancies attending to their first-trimester assessment in Murcia, Spain, and second, all singleton pregnancies having a CVS following first-trimester assessment at any of the participating centers. We used propensity score matching analysis to estimate the association between CVS and miscarriage. We compared risks of miscarriage of CVS and non-CVS groups after propensity score matching (1:1 ratio). This procedure creates two comparable groups balancing the maternal and pregnancy characteristics that lead to CVS, in a similar way in which randomization operates in a randomized clinical trial. RESULTS: The study population consisted of 22,250 participants in the non-CVS group and 3,613 in the CVS group. The incidence of miscarriage in the CVS group was 2.1% (77/3,613), which was significantly higher than the 0.9% (207/22,250) in the non-CVS group (p <0.001). The propensity score algorithm matched 2,122 CVS cases with 2,122 non-CVS cases including 40 (1.9%) and 55 (2.6%) miscarriages in the CVS and non-CVS groups, respectively (OR 0.72 [95% CI 0.48 to 1.10]; p = 0.146). However, we found a significant interaction between the CVS risk of miscarriage and the risk of aneuploidies, suggesting a different effect of the CVS for different baseline characteristics in such a way that, when the risk of aneuploidies is low, the risk after CVS increases (OR 2.87 [95% CI 1.13 to 7.30]) but when the risk is high, the risk after CVS is paradoxically reduced (OR 0.47 [95% CI 0.28 to 0.76]), presumably due to prenatal diagnosis and termination of major aneuploidies that would have otherwise resulted in spontaneous miscarriage. CONCLUSIONS: The risk of miscarriage in women having a CVS is about 1% higher than in women without CVS, although this excess risk is not entirely due to the invasive procedure but to some extent the demographic and pregnancy characteristics of the patient undergoing CVS. After accounting for these risk factors and confining the analysis to low-risk pregnancies, CVS seems to increase the risk of miscarriage about three times above the patient's background-risk. Although this is a substantial increase in relative terms, in pregnancies without risk factors, the risk of miscarriage after CVS will still remain low and similar to or slightly higher than that of the general population. For example, if her risk of aneuploidy is 1 in a 1,000 (0.1%), her risk of miscarriage after CVS will increase to 0.3% (0.2% higher)

    Two highly divergent alcohol dehydrogenases of melon exhibit fruit ripening-specific expression and distinct biochemical characteristics

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    Alcohol dehydrogenases (ADH) participate in the biosynthetic pathway of aroma volatiles in fruit by interconverting aldehydes to alcohols and providing substrates for the formation of esters. Two highly divergent ADH genes (15% identity at the amino acid level) of Cantaloupe Charentais melon (Cucumis melo var. Cantalupensis) have been isolated. Cm-ADH1 belongs to the medium-chain zinc-binding type of ADHs and is highly similar to all ADH genes expressed in fruit isolated so far. Cm-ADH2 belongs to the short-chain type of ADHs. The two encoded proteins are enzymatically active upon expression in yeast. Cm-ADH1 has strong preference for NAPDH as a co-factor, whereas Cm-ADH2 preferentially uses NADH. Both Cm-ADH proteins are much more active as reductases with Kms 10–20 times lower for the conversion of aldehydes to alcohols than for the dehydrogenation of alcohols to aldehydes. They both show strong preference for aliphatic aldehydes but Cm-ADH1 is capable of reducing branched aldehydes such as 3-methylbutyraldehyde, whereas Cm-ADH2 cannot. Both Cm-ADH genes are expressed specifically in fruit and up-regulated during ripening. Gene expression as well as total ADH activity are strongly inhibited in antisense ACC oxidase melons and in melon fruit treated with the ethylene antagonist 1-methylcyclopropene (1-MCP), indicating a positive regulation by ethylene. These data suggest that each of the Cm-ADH protein plays a specific role in the regulation of aroma biosynthesis in melon fruit

    Identification and multi-environment validation of resistance to rust (Uromyces viciae-fabae) in Vicia faba

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    A germplasm collection of 484 accessions of Vicia faba was screened for resistance to rust (Uromyces viciae-fabae) under field conditions. Accessions varied in the levels of rust infection, although no complete resistance was identified. Stability of resistance of the 39 most-resistant accessions was tested in a multi-location experiment in Austria, Egypt, Tunisia, United Kingdom and Spain over three additional field seasons. Genotype×environment interaction accounted for 43% of the sum of squares of the multi-environment evaluation, revealing instability of the phenotypic expression across environments. This might hamper the efficiency of selection suggesting the need for selection in different environments. Three possible mega-environments were discerned in the studied area, Mediterranean (Spain, Tunisia and Egypt), Oceanic (UK) and Continental (Austria). Córdoba (Spain) and Kafr El-Sheik (Egypt) showed as ideal environments for rust resistance screenings within Mediterranean environment. Several accessions (300, 303, 311, 313, 720, 1196 and 1271) were grouped as moderately to highly resistant in the three defined mega-environments. These accessions showed clear differences both in terms of reduced disease severity and high stability, which make them good candidates for international faba bean breeding programmes. Concerning each mega-environment, accessions 300 and 311 were the most resistant and stable ones across the Mediterranean one, followed by accessions 720, 1022, 1272, 1320 and BPL261. On the contrary other accessions (313, 452, 481 and 1196) were the most resistant in Oceanic and Continental environments. However, 452 and 481 were susceptible in the Mediterranean mega-environment. This contrasting performance across the environments was also supported by contradictory performance of the checks BPL261 and Baraca in Oceanic and Continental environments, suggesting differential virulence in rust populations, which deserves further attention.Published versio

    Search for Axionlike and Scalar Particles with the NA64 Experiment

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    We carried out a model-independent search for light scalar (s) and pseudoscalar axionlike (a) particles that couple to two photons by using the high-energy CERN SPS H4 electron beam. The new particles, if they exist, could be produced through the Primakoff effect in interactions of hard bremsstrahlung photons generated by 100 GeV electrons in the NA64 active dump with virtual photons provided by the nuclei of the dump. The a(s) would penetrate the downstream HCAL module, serving as shielding, and would be observed either through their a(s)γγa(s)\to\gamma \gamma decay in the rest of the HCAL detector or as events with large missing energy if the a(s) decays downstream of the HCAL. This method allows for the probing the a(s) parameter space, including those from generic axion models, inaccessible to previous experiments. No evidence of such processes has been found from the analysis of the data corresponding to 2.84×10112.84\times10^{11} electrons on target allowing to set new limits on the a(s)γγa(s)\gamma\gamma-coupling strength for a(s) masses below 55 MeV.Comment: This publication is dedicated to the memory of our colleague Danila Tlisov. 7 pages, 5 figures, revised version accepted for publication in Phys. Rev. Let

    The Effective Fragment Molecular Orbital Method for Fragments Connected by Covalent Bonds

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    We extend the effective fragment molecular orbital method (EFMO) into treating fragments connected by covalent bonds. The accuracy of EFMO is compared to FMO and conventional ab initio electronic structure methods for polypeptides including proteins. Errors in energy for RHF and MP2 are within 2 kcal/mol for neutral polypeptides and 6 kcal/mol for charged polypeptides similar to FMO but obtained two to five times faster. For proteins, the errors are also within a few kcal/mol of the FMO results. We developed both the RHF and MP2 gradient for EFMO. Compared to ab initio, the EFMO optimized structures had an RMSD of 0.40 and 0.44 {\AA} for RHF and MP2, respectively.Comment: Revised manuscrip

    MFV Reductions of MSSM Parameter Space

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    The 100+ free parameters of the minimal supersymmetric standard model (MSSM) make it computationally difficult to compare systematically with data, motivating the study of specific parameter reductions such as the cMSSM and pMSSM. Here we instead study the reductions of parameter space implied by using minimal flavour violation (MFV) to organise the R-parity conserving MSSM, with a view towards systematically building in constraints on flavour-violating physics. Within this framework the space of parameters is reduced by expanding soft supersymmetry-breaking terms in powers of the Cabibbo angle, leading to a 24-, 30- or 42-parameter framework (which we call MSSM-24, MSSM-30, and MSSM-42 respectively), depending on the order kept in the expansion. We provide a Bayesian global fit to data of the MSSM-30 parameter set to show that this is manageable with current tools. We compare the MFV reductions to the 19-parameter pMSSM choice and show that the pMSSM is not contained as a subset. The MSSM-30 analysis favours a relatively lighter TeV-scale pseudoscalar Higgs boson and tanβ10\tan \beta \sim 10 with multi-TeV sparticles.Comment: 2nd version, minor comments and references added, accepted for publication in JHE

    Sexuality throughout all the stages of pregnancy: experiences of expectant mothers

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    Objective: To explore and understand the sexual experiences of expectant mothers during their pregnancy. Methods: The study was carried out in two healthcare centers in the Almería Health District, in southern Spain. The participants included pregnant women who received prenatal care and/or maternity education. The inclusion criteria were being pregnant, maintaining sexual activity and agreeing to participate in the study. The exclusion criteria were having limitations on sexual activity by medical prescription. The sample consisted of 15 expectant women selected using a convenience sample, of which 5 took part in a focus group (FG) and 10 in in-depth interviews (IDI). Data was collected between the months of June and December 2016. Participants were contacted by the main researcher and an appointment was made to carry out the FGs or the IDIs. Results: Three main categories emerged: False beliefs and a holistic approach to sexuality during pregnancy, which is related to the concept of sexuality, false beliefs, and limited sexual counseling during pregnancy. Limitations: From fear at the beginning to physical diffi culty at the end, referring to the fluctuations in sexual desire as well as the physical changes that limit sexual activity. Adapting to changes: safe practices and satisfaction with one’s body image, which encompasses concerns about the risks and the relationship between body image and self-esteem. Conclusion: A lack of sexual counseling during pregnancy leads to the creation of false beliefs, which, together with physical changes, concerns about the risk, and fl uctuations in sexual desire and interest, bring about a decrease in sexual activity. But sexuality remains an important aspect of pregnancy, toward which the participants must adopt a broader approach, not limited to intercourse, and adopt sexual practices that are adapted to the physical and emotional changes that happen during this time
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