372 research outputs found
Quantum quenches of ion Coulomb crystals across structural instabilities
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
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
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
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
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
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
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
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
We consider the moment space corresponding to complex matrix measures defined on ( or K=\D). We endow this
set with the uniform law. We are mainly interested in large deviations
principles (LDP) when . First we fix an integer and
study the vector of the first components of a random element of
. We obtain a LDP in the set of -arrays of
matrices. Then we lift a random element of 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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