690 research outputs found

    Superfluid turbulence from quantum Kelvin wave to classical Kolmogorov cascades

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    A novel unitary quantum lattice gas algorithm is used to simulate quantum turbulence of a BEC described by the Gross-Pitaevskii equation on grids up to 5760^3. For the first time, an accurate power law scaling for the quantum Kelvin wave cascade is determined: k^{-3}. The incompressible kinetic energy spectrum exhibits very distinct power law spectra in 3 ranges of k-space: a classical Kolmogorov k^{-5/3} spectrum at scales much greater than the individual quantum vortex cores, and a quantum Kelvin wave cascade spectrum k^{-3} on scales of order the vortex cores. In the semiclassical regime between these two spectra there is a pronounced steeper spectral decay, with non-universal exponent. The Kelvin k^{-3} spectrum is very robust, even on small grids, while the Kolmogorov k^{-5/3} spectrum becomes more and more apparent as the grids increase from 2048^3 grids to 5760^3.Comment: 4 pages, 2 figure

    Employing Spatial Metrics in Urban Land-Use / Land-Cover Mapping: Comparing the Getis and Geary Indices

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    We examine the potential of supplementing per-pixel classifiers with the Getis index (Gi) in comparison to the Geary’s C on a subset of Ikonos imagery for urban land-use and land-cover classification. The test is pertinent considering that the Gi is generally considered more capable of identifying clusters of points with similar attributes. We quantify the impact of varying distance thresholds on the classification product and demonstrate how well the Gi identified cold and hot spots in comparison to Geary’s C. The exercise also provides a rule of thumb for effectively measuring spatial association in connection to adjacency. We are able to support existing literature that measuring local variability improves classification over spectral information alone. The results, however, neither confirm nor deny the challenge on whether measuring cold and hot spots rather than just spatial association improves classification accuracy

    Brachybacterium nesterenkovii isolated from a human blood culture-a first report

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    Brachybacterium is a genus of Gram-positive bacteria that rarely causes infections in humans. Here we report the case of an 8-month-old infant who presented with an acute febrile illness. During the diagnostic process, a blood culture was positive with Gram-positive cocci that were identified as Brachybacterium nesterenkovii by MALDI-TOF. As a result of the unclear clinical significance of this isolate and the continuous febrile state, a second blood culture was taken and returned B. nesterenkovii once more. To our knowledge this is the first time that B. nesterenkovii has been isolated from human blood cultures during the course of a systemic infection

    Towards precision medicine for pain: diagnostic biomarkers and repurposed drugs

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    We endeavored to identify objective blood biomarkers for pain, a subjective sensation with a biological basis, using a stepwise discovery, prioritization, validation, and testing in independent cohorts design. We studied psychiatric patients, a high risk group for co-morbid pain disorders and increased perception of pain. For discovery, we used a powerful within-subject longitudinal design. We were successful in identifying blood gene expression biomarkers that were predictive of pain state, and of future emergency department (ED) visits for pain, more so when personalized by gender and diagnosis. MFAP3, which had no prior evidence in the literature for involvement in pain, had the most robust empirical evidence from our discovery and validation steps, and was a strong predictor for pain in the independent cohorts, particularly in females and males with PTSD. Other biomarkers with best overall convergent functional evidence for involvement in pain were GNG7, CNTN1, LY9, CCDC144B, and GBP1. Some of the individual biomarkers identified are targets of existing drugs. Moreover, the biomarker gene expression signatures were used for bioinformatic drug repurposing analyses, yielding leads for possible new drug candidates such as SC-560 (an NSAID), and amoxapine (an antidepressant), as well as natural compounds such as pyridoxine (vitamin B6), cyanocobalamin (vitamin B12), and apigenin (a plant flavonoid). Our work may help mitigate the diagnostic and treatment dilemmas that have contributed to the current opioid epidemic

    Exploring the predictive power of impulsivity measures in predicting self-reported and informant-reported inpatient disruptive behaviors

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    Contains fulltext : 231148.pdf (Publisher’s version ) (Open Access)Impulsivity is strongly associated with aggression and antisocial conduct. Although self-report measures are a time-efficient means to assess impulsivity, they may be susceptible to socially desirable responding, particularly in forensic psychiatry. The current study aimed to investigate the predictive validity of three measures of impulsivity in predicting self- and informant-reported antisocial behavior: the Barratt Impulsiveness Scale, the Self-Centered Impulsivity scale of the Psychopathic Personality Inventory-Revised and the general Disinhibition factor of the Externalizing Spectrum Inventory. Next, the mediating role of a measure of self-deception, the Virtuous Responding scale, was examined in these associations. Participants (N = 94) were inpatients from addiction care and forensic psychiatry. Two regression analyses were conducted using self-reported antisocial behavior in the first, and informant-reported antisocial behavior in the second analysis as outcome variables. In addition, a mediated regression analysis was conducted, using the Virtuous Responding scale as a mediator. The impulsivity measures showed a substantially lower predictive validity when informant-reported behavior was predicted. The Virtuous Responding scale appeared to be unreliable in the current sample and showed no mediation effect. The results showed insufficient support for the predictive validity of the three measures of impulsivity. Alternative time-efficient assessments for impulsivity are needed, such as informant-based measures.18 p

    The cost of inbreeding in a socially polymorphic ant population

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    Trabalho de projecto de mestrado em Medicina (Gastroenterologia), apresentado á Faculdade de Medicina da Universidade de CoimbraA encefalopatia hepática é uma das principais complicações da doença hepática crónica e pode estar presente em 50 a 70% de todos os pacientes cirróticos, incluindo aqueles com alterações demonstráveis apenas por testes psicométricos, sendo uma complicação de grande relevância clínica. Na insuficiência hepática aguda, os doentes podem sucumbir a uma morte neurológica, com edema cerebral e hipertensão intracraniana. A sobrevida em pacientes com doença hepática crónica depende da avaliação dos critérios da classificação de Child-Pugh que reconhece a importância prognóstica da encefalopatia hepática. Esta complicação da doença hepática, aguda ou crónica, resulta da diminuição da actividade hepática com incapacidade marcada de eliminação de determinadas toxinas do organismo. Hoje sabe-se que os astrócitos, nomeadamente as células de Alzheimer tipo II, tem um papel importante na fisiopatologia da encefalopatia hepática. A epidemiologia e a fisiopatologia da encefalopatia hepática permanecem ainda apenas parcialmente esclarecidas, tornando este tema fonte importante de estudos constantes. O trabalho proposto tem como objectivo uma actualizada revisão bibliográfica, centrando-se nos últimos avanços científicos sobre esta alteração neuropsiquiátrica. Com este trabalho, propõe-se estudar os diferentes métodos de diagnóstico, indicações das diferentes opções terapêuticas, comparando-as entre si, identificar o impacto económico e social da encefalopatia hepática, assim como perceber os mecanismos fisiopatológicos que contribuem para esta grave alteraçãoHepatic encephalopathy is one of the main complications of chronic liver disease and can occur in 50 to 70% of all cirrhotic patients, including those with alterations demonstrated only through psychometric tests, being a complication of great clinical relevance. In severe liver failure, patients can perish due to neurological death, with brain swelling and intracranial hypertension. Chronic liver disease patients’ survival time depends on the evaluation of Child- Pugh classification criteria that recognizes the prognostic importance of hepatic encephalopathy. This liver disease complication, chronic or severe, is a result of the reduction of liver activity with marked incapacity to eliminate certain toxins from the organism. Today it is known that astrocytes, namely Alzheimer type II cells, have an important role in hepatic encephalopathy physiopathology. The epidemiology and physiopathology of hepatic encephalopathy still remain partially clarified, becoming this subject an important source of constant studies. The main goal of this study is to make an actualized bibliographical revision, grounded on the last scientific advances on this neuropsychiatric abnormality. Through this work, one considers studying the different diagnostic methods, the different therapeutic option indications, by comparing them, identifying the economic and social impact of hepatic encephalopathy, as well as understanding the physiopathological mechanisms that contribute for this serious abnormalit

    Psychometric Properties of the Externalizing Spectrum Inventory:Replication and Extension across Clinical and Non-Clinical Samples

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    The Externalizing Spectrum Inventory aims at assessing personality features that underlie externalizing disorders such as substance abuse and antisocial behaviors. The objective was to replicate the psychometric properties of the 160-item Externalizing Spectrum Inventory in Dutch clinical and non-clinical samples. First, Cronbach's alpha, test-retest reliability and the factor structure were analyzed on a mixed sample of inpatients (n = 149), undergraduates (n = 227), and community participants (n = 178). The factor structure was evaluated through confirmatory and exploratory factor analyses; for the latter Parallel Analysis was used, based on Minimum Rank Factor Analysis. Next, the criterion validity was analyzed using the Aggression Questionnaire and the NEO-Five Factor Inventory as external measures. The Dutch Externalizing Spectrum Inventory subscales showed sufficient reliability (α=.68-.94; ICC=.68-.91), except in the undergraduate sample (α=.49-.96; ICC=.43-.97). The factor structure of the Externalizing Spectrum Inventory was not confirmed and the exploratory analysis yielded different factor solutions across samples. The criterion validity was supported with regard to trait aggression and partly supported with regard to the Five Factor Model. The results suggest that the ESI-160 and its original factor model can be used for prediction purposes. However, further research of the factor structure is strongly recommended

    Universal quantum control of an atomic spin qubit on a surface

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    Scanning tunneling microscopy (STM) enables the bottom-up fabrication of tailored spin systems on a surface that are engineered with atomic precision. When combining STM with electron spin resonance (ESR), these single atomic and molecular spins can be controlled quantum-coherently and utilized as electron-spin qubits. Here we demonstrate universal quantum control of such a spin qubit on a surface by employing coherent control along two distinct directions, achieved with two consecutive radio-frequency (RF) pulses with a well-defined phase difference. We first show transformations of each Cartesian component of a Bloch vector on the quantization axis, followed by ESR-STM detection. Then we demonstrate the ability to generate an arbitrary superposition state of a single spin qubit by using two-axis control schemes, in which experimental data show excellent agreement with simulations. Finally, we present an implementation of two-axis control in dynamical decoupling. Our work extends the scope of STM-based pulsed ESR, highlighting the potential of this technique for quantum gate operations of electron-spin qubits on a surface

    Transplantation of Skeletal Muscle-Derived Sca-1⁺/PW1⁺/Pax7⁻ Interstitial Cells (PICs) Improves Cardiac Function and Attenuates Remodeling in Mice Subjected to Myocardial Infarction

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    We have previously shown that skeletal muscle-derived Sca-1⁺/PW1⁺/Pax7⁻ interstitial cells (PICs) are multi-potent and enhance endogenous repair and regeneration. Here, we investigated the regenerative potential of PICs following intramyocardial transplantation in mice subjected to an acute myocardial infarction (MI). MI was induced through the ligation of the left anterior descending coronary artery in 8-week old male C57BL/6 mice. 5 × 10⁵ eGFP-labelled PICs (MI + PICs; n = 7) or PBS (MI-PBS; n = 7) were injected intramyocardially into the border zone. Sham mice (n = 8) were not subjected to MI, or the transplantation of PICs or PBS. BrdU was administered via osmotic mini-pump for 14 days. Echocardiography was performed prior to surgery (baseline), and 1-, 3- and 6-weeks post-MI and PICs transplantation. Mice were sacrificed at 6 weeks post-MI + PICs transplantation, and heart sections were analysed for fibrosis, hypertrophy, engraftment, proliferation, and differentiation of PICs. A significant (\u1d631 < 0.05) improvement in ejection fraction (EF) and fractional shortening was observed in the MI-PICs group, compared to MI + PBS group at 6-weeks post MI + PICs transplantation. Infarct size/fibrosis of the left ventricle significantly (\u1d631 < 0.05) decreased in the MI-PICs group (14.0 ± 2.5%), compared to the MI-PBS group (32.8 ± 2.2%). Cardiomyocyte hypertrophy in the border zone significantly (\u1d631 < 0.05) decreased in the MI-PICs group compared to the MI-PBS group (330.0 ± 28.5 µM2 vs. 543.5 ± 26.6 µm2), as did cardiomyocyte apoptosis (0.6 ± 0.9% MI-PICs vs. 2.8 ± 0.8% MI-PBS). The number of BrdU+ cardiomyocytes was significantly (\u1d631 < 0.05) increased in the infarct/border zone of the MI-PICs group (7.0 ± 3.3%), compared to the MI-PBS group (1.7 ± 0.5%). The proliferation index (total BrdU+ cells) was significantly increased in the MI-PICs group compared to the MI-PBS group (27.0 ± 3.4% vs. 7.6 ± 1.0%). PICs expressed and secreted pro-survival and reparative growth factors, supporting a paracrine effect of PICs during recovery/remodeling. Skeletal muscle-derived PICs show significant reparative potential, attenuating cardiac remodelling following transplantation into the infarcted myocardium. PICs can be easily sourced from skeletal muscle and therefore show promise as a potential cell candidate for supporting the reparative and regenerative effects of cell therapie
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