372 research outputs found

    Quantum quenches of ion Coulomb crystals across structural instabilities

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    Quenches in an ion chain can create coherent superpositions of motional states across the linear-zigzag structural transition. The procedure has been described in [Phys. Rev. A 84, 063821 (2011)] and makes use of spin-dependent forces, so that a coherent superposition of the electronic states of one ion evolves into an entangled state between the chain's internal and external degrees of freedom. The properties of the crystalline state so generated are theoretically studied by means of Ramsey interferometry on one ion of the chain. An analytical expression for the visibility of the interferometric measurement is obtained for a chain of arbitrary number of ions and as a function of the time elapsed after the quench. Sufficiently close to the linear-zigzag instability the visibility decays very fast, but exhibits revivals at the period of oscillation of the mode that drives the structural instability. These revivals have a periodicity that is independent of the crystal size, and they signal the creation of entanglement by the quantum quench.Comment: 14 pages, 8 figures; added a paragraph in the introduction providing more background, added paragraph at the end of Sec. IV discussing experimental parameter

    Механические испытания элементов космической техники на синусоидальные воздействия

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    Целью работы является определение собственных частот трехмерной модели двигателя-маховика системы ориентации малого космического аппарата, а также ее поведение под действием квазистатической нагрузки, синусоидальных и случайных вибраций, акустического и ударного воздействия. Компьютерный анализ, проведенный в процессе проектирования, позволяет определить характеристики изделия и провести оптимизацию конструкции без создания опытного образца. Анализ проводился с помощью специального программного обеспечения "T-Flex Анализ". Исходная трехмерная модель была разбита на три подсборки: корпусную, роторную и статорную. Приведены результаты частотного анализа и расчета при воздействии на двигатель-маховик квазистатических нагрузок. По результатам проведенного компьютерного конечно-элементного анализа можно сказать, что спроектированный двигатель-маховик с большим запасом удовлетворяет требованиям надежности. Большие коэффициенты запасов говорят о том, что конструкцию в дальнейшем можно оптимизировать

    Enhanced gene trapping in mouse embryonic stem cells

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    Gene trapping is used to introduce insertional mutations into genes of mouse embryonic stem cells (ESCs). It is performed with gene trap vectors that simultaneously mutate and report the expression of the endogenous gene at the site of insertion and provide a DNA tag for rapid identification of the disrupted gene. Gene traps have been employed worldwide to assemble libraries of mouse ESC lines harboring mutations in single genes, which can be used to make mutant mice. However, most of the employed gene trap vectors require gene expression for reporting a gene trap event and therefore genes that are poorly expressed may be under-represented in the existing libraries. To address this problem, we have developed a novel class of gene trap vectors that can induce gene expression at insertion sites, thereby bypassing the problem of intrinsic poor expression. We show here that the insertion of the osteopontin enhancer into several conventional gene trap vectors significantly increases the gene trapping efficiency in high-throughput screens and facilitates the recovery of poorly expressed genes

    The optimal unitary dilation for bosonic Gaussian channels

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    A generic quantum channel can be represented in terms of a unitary interaction between the information-carrying system and a noisy environment. Here, the minimal number of quantum Gaussian environmental modes required to provide a unitary dilation of a multi-mode bosonic Gaussian channel is analyzed both for mixed and pure environment corresponding to the Stinespring representation. In particular, for the case of pure environment we compute this quantity and present an explicit unitary dilation for arbitrary bosonic Gaussian channel. These results considerably simplify the characterization of these continuous-variable maps and can be applied to address some open issues concerning the transmission of information encoded in bosonic systems.Comment: 9 page

    New Aspects in the Differential Diagnosis and Therapy of Bladder Pain Syndrome/Interstitial Cystitis

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    Diagnosis of bladder pain syndrome/interstitial cystitis (BPS/IC) is presently based on mainly clinical symptoms. BPS/IC can be considered as a worst-case scenario of bladder overactivity of unknown origin, including bladder pain. Usually, patients are partially or completely resistant to anticholinergic therapy, and therapeutical options are especially restricted in case of BPS/IC. Therefore, early detection of patients prone to develop BPS/IC symptoms is essential for successful therapy. We propose extended diagnostics including molecular markers. Differential diagnosis should be based on three diagnostical “columns”: (i) clinical diagnostics, (ii) histopathology, and (iii) molecular diagnostics. Analysis of molecular alterations of receptor expression in detrusor smooth muscle cells and urothelial integrity is necessary to develop patient-tailored therapeutical concepts. Although more research is needed to elucidate the pathomechanisms involved, extended BPS/IC diagnostics could already be integrated into routine patient care, allowing evidence-based pharmacotherapy of patients with idiopathic bladder overactivity and BPS/IC

    Protease Expression Levels in Prostate Cancer Tissue Can Explain Prostate Cancer-Associated Seminal Biomarkers: An Explorative Concept Study

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    Previously, we described prostate cancer (PCa) detection (83% sensitivity; 67% specificity) in seminal plasma by CE-MS/MS. Moreover, advanced disease was distinguished from organ-confined tumors with 80% sensitivity and 82% specificity. The discovered biomarkers were naturally occurring fragments of larger seminal proteins, predominantly semenogelin 1 and 2, representing endpoints of the ejaculate liquefaction. Here we identified proteases putatively involved in PCa specific protein cleavage, and examined gene expression and tissue protein levels, jointly with cell localization in normal prostate (nP), benign prostate hyperplasia (BPH), seminal vesicles and PCa using qPCR, Western blotting and confocal laser scanning microscopy. We found differential gene expression of chymase (CMA1), matrix metalloproteinases (MMP3, MMP7), and upregulation of MMP14 and tissue inhibitors (TIMP1 and TIMP2) in BPH. In contrast tissue protein levels of MMP14 were downregulated in PCa. MMP3/TIMP1 and MMP7/TIMP1 ratios were decreased in BPH. In seminal vesicles, we found low-level expression of most proteases and, interestingly, we also detected TIMP1 and low levels of TIMP2. We conclude that MMP3 and MMP7 activity is different in PCa compared to BPH due to fine regulation by their inhibitor TIMP1. Our findings support the concept of seminal plasma biomarkers as non-invasive tool for PCa detection and risk stratification

    Industrial Data Science: Developing a Qualification Concept for Machine Learning in Industrial Production

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    The advent of Industry 4.0 and the availability of large data storage systems lead to an increasing demand for specially educated data-oriented professionals in industrial production. The education of these specialists should combine elements from three fields: Industrial engineering, data analysis and data administration. However, a comprehensive education program incorporating all three elements has not yet been established in Germany. The aim of the acquired research project, titled “Industrial Data Science” is to develop and implement a qualification concept for Machine Learning based on demands coming up in industrial environments. The concept is targeted at two groups: Advanced students from any of the three mentioned fields (Mechanical Engineering, Statistics, Computer Science) and industrial professionals. In the qualification concept the needs of industrial companies are considered. Therefore, a survey was created to inquire the use and potentials of Machine Learning and the requirements for future Data Scientists in industrial production. The evaluation of the survey and the resulting conclusions affecting the qualification concept are presented in this paper

    Detection of liver dysfunction using a wearable electronic nose system based on semiconductor metal oxide sensors

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    The purpose of this exploratory study was to determine whether liver dysfunction can be generally classified using a wearable electronic nose based on semiconductor metal oxide (MOx) gas sensors, and whether the extent of this dysfunction can be quantified. MOx gas sensors are attractive because of their simplicity, high sensitivity, low cost, and stability. A total of 30 participants were enrolled, 10 of them being healthy controls, 10 with compensated cirrhosis, and 10 with decompensated cirrhosis. We used three sensor modules with a total of nine different MOx layers to detect reducible, easily oxidizable, and highly oxidizable gases. The complex data analysis in the time and non-linear dynamics domains is based on the extraction of 10 features from the sensor time series of the extracted breathing gas measurement cycles. The sensitivity, specificity, and accuracy for distinguishing compensated and decompensated cirrhosis patients from healthy controls was 1.00. Patients with compensated and decompensated cirrhosis could be separated with a sensitivity of 0.90 (correctly classified decompensated cirrhosis), a specificity of 1.00 (correctly classified compensated cirrhosis), and an accuracy of 0.95. Our wearable, non-invasive system provides a promising tool to detect liver dysfunctions on a functional basis. Therefore, it could provide valuable support in preoperative examinations or for initial diagnosis by the general practitioner, as it provides non-invasive, rapid, and cost-effective analysis results

    Large Deviations for Random Matricial Moment Problems

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    We consider the moment space MnK\mathcal{M}_n^{K} corresponding to p×pp \times p complex matrix measures defined on KK (K=[0,1]K=[0,1] or K=\D). We endow this set with the uniform law. We are mainly interested in large deviations principles (LDP) when nn \rightarrow \infty. First we fix an integer kk and study the vector of the first kk components of a random element of MnK\mathcal{M}_n^{K}. We obtain a LDP in the set of kk-arrays of p×pp\times p matrices. Then we lift a random element of MnK\mathcal{M}_n^{K} into a random measure and prove a LDP at the level of random measures. We end with a LDP on Carth\'eodory and Schur random functions. These last functions are well connected to the above random measure. In all these problems, we take advantage of the so-called canonical moments technique by introducing new (matricial) random variables that are independent and have explicit distributions.Comment: 34 page
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