19 research outputs found

    Trapping and binding by dephasing

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    The binding and trapping of particles usually rely on conservative forces, described by unitary quantum dynamics. We show that both can also arise solely from spatially dependent dephasing, the simplest type of decoherence. This can be based on continuous weak position measurements in only selected regions of space, for which we propose a practical realisation. For a single particle, we demonstrate a quantum particle-in-the-box based on dephasing. For two particles, we demonstrate their binding despite repulsive interactions, if their molecular states are dephased at large separations only. Both mechanisms are experimentally accessible, as we show for an example with Rydberg atoms in a cold gas background.Comment: 9 pages, 8 figure

    Complexity of Maximum Cut on Interval Graphs

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    We resolve the longstanding open problem concerning the computational complexity of Max Cut on interval graphs by showing that it is NP-complete

    Age-related Variations in Anthropometry, Body Composition and Nutritional Status among the Adult Kheria Sabar Males of Purulia, West Bengal, India

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    Undernutrition and ageing may have a significant effect on body composition. A cross sectional study was conducted to explore the age-related variations among different anthropometric and body composition characteristics amongst the adult Kheria Sabar males of Purulia district of West Bengal. From fifteen villages, 304 apparently healthy adult males aged 18–60 years were selected at random. Subjects were categorized into four age groups and standard anthropometric measurements were used like height (HT), weight (WT), mid-upper-arm circumference (MUAC) and skinfolds of biceps (BSF), triceps (TSF) and sub-scapular (SSSF) region. Derived variables of body mass index (BMI), per cent body fat (PBF), fat mass (FM), fat-free mass (FFM), fat mass index (FMI) and fat-free mass index (FFMI) were also calculated. Majority of the variables were found to be inversely correlated with age. Positive (HT, WT, MUAC, BMI, FFM and FFMI) and negative (FM and FMI) significant differences were observed across different age groups. It was also observed that the frequency of undernutrition (62.6%) was the highest among the elderly people with 47.6% overall prevalence. This study clearly indicates that among the undernourished individuals, older people were more vulnerable to malnutrition and thus immediate nutritional intervention is required

    Two-dimensional spectroscopy of Rydberg gases

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    Two-dimensional (2D) spectroscopy uses multiple electromagnetic pulses to infer the properties of a complex system. A paradigmatic class of target systems are molecular aggregates, for which one can obtain information on the eigenstates, various types of static and dynamic disorder and on relaxation processes. However, two-dimensional spectra can be difficult to interpret without precise knowledge of how the signal components relate to microscopic Hamiltonian parameters and system-bath interactions. Here we show that two-dimensional spectroscopy can be mapped in the microwave domain to highly controllable Rydberg quantum simulators. By porting 2D spectroscopy to Rydberg atoms, we firstly open the possibility of its experimental quantum simulation, in a case where parameters and interactions are very well known. Secondly, the technique may provide additional handles for experimental access to coherences between system states and the ability to discriminate different types of decoherence mechanisms in Rydberg gases. We investigate the requirements for a specific implementation utilizing multiple phase coherent microwave pulses and a phase cycling technique to isolate signal components.Comment: 34 pages, 9 figure

    Restoration of neglected fracture dislocation hip in elderly: a case report

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    Neglected traumatic fracture dislocation of the hip is a challenging problem due to soft tissue contractures, adhesions, fibro fatty tissue filling acetabulum, avascular necrosis, arthritis and myositis ossificans. These types of injury often get missed at initial evaluation in the presence of distracting injuries and in poly trauma patients. Femoral head fractures account for only 7-16% of all hip fracture dislocations, with combined femoral head and acetabular fractures in elderly being even lower. Literature favours primary hip replacement as compared to hip salvage in age above 60 years and in patients with neglected hip fracture dislocations of more than 3 months duration due to high chances of afore mentioned complications. Here, we report a case of 69 years old male with neglected hip fracture dislocation associated with posterior acetabular wall and femoral head fracture for the challenges in management with a total hip replacement

    Generation, characterization, and use of EKLF(Klf1)/CRE knock-in mice for cell-restricted analyses

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    IntroductionEKLF/Klf1 is a tissue-restricted transcription factor that plays a critical role in all aspects of erythropoiesis. Of particular note is its tissue-restricted pattern of expression, a property that could prove useful for expression control of a linked marker or enzymatic gene.Methods and resultsWith this in mind, we fused the CRE recombinase to the genomic EKLF coding region and established mouse lines. We find by FACS analyses that CRE expression driven by the EKLF transcription unit recapitulates erythroid-restricted expression with high penetrance in developing embryos. We then used this line to test its properties in the adult, where we found EKLF/CRE is an active and is a robust mimic of normal EKLF expression in the adult bone marrow. EKLF/CRE is also expressed in erythroblastic island macrophage in the fetal liver, and we demonstrate for the first time that, as seen during embryonic development, EKLF is also expressed in adult BM-derived erythroblastic island macrophage. Our data also support lineage studies showing EKLF expression at early stages of hematopoiesis.DiscussionThe EKLF/CRE mouse lines are novel reagents whose availability will be of great utility for future experiments by investigators in the red cell field

    Geometric Decision Rules for Instance-based Learning Problems

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    In the typical nonparametric approach to classification in instance-based learning and data mining, random data (the training set of patterns) are collected and used to design a decision rule (classifier)

    Geometric Decision Rules for High Dimensions

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    In this paper we report on a new approach to the instance-based learning problem
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