517 research outputs found
Fragmentation Functions Beyond Fixed Order Accuracy
We give a detailed account of the phenomenology of all-order resummations of
logarithmically enhanced contributions at small momentum fraction of the
observed hadron in semi-inclusive electron-positron annihilation and the
time-like scale evolution of parton-to-hadron fragmentation functions. The
formalism to perform resummations in Mellin moment space is briefly reviewed,
and all relevant expressions up to next-to-next-to-leading logarithmic order
are derived, including their explicit dependence on the factorization and
renormalization scales. We discuss the details pertinent to a proper numerical
implementation of the resummed results comprising an iterative solution to the
time-like evolution equations, the matching to known fixed-order expressions,
and the choice of the contour in the Mellin inverse transformation. First
extractions of parton-to-pion fragmentation functions from semi-inclusive
annihilation data are performed at different logarithmic orders of the
resummations in order to estimate their phenomenological relevance. To this
end, we compare our results to corresponding fits up to fixed,
next-to-next-to-leading order accuracy and study the residual dependence on the
factorization scale in each case.Comment: 19 pages, 7 figure
Using hadron-in-jet data in a global analysis of fragmentation functions
We present a novel global QCD analysis of charged -meson fragmentation
functions at next-to-leading order accuracy. This is achieved by making use of
the available data for single-inclusive -meson production in
electron-positron annihilation, hadron-hadron collisions, and, for the first
time, in-jet fragmentation in proton-proton scattering. It is shown how to
include all relevant processes efficiently and without approximations within
the Mellin moment technique, specifically for the in-jet fragmentation cross
section. The presented technical framework is generic and can be
straightforwardly applied to future analyses of fragmentation functions for
other hadron species, as soon as more in-jet fragmentation data become
available. We choose to work within the Zero Mass Variable Flavor Number Scheme
which is applicable for sufficiently high energies and transverse momenta. The
obtained optimum set of parton-to- fragmentation functions is
accompanied by Hessian uncertainty sets which allow one to propagate
hadronization uncertainties to other processes of interest.Comment: 16 pages, 8 figure
BMI-mortality association: shape independent of smoking status but different for chronic lung disease and lung cancer
Real-Time Neural MPC: Deep Learning Model Predictive Control for Quadrotors and Agile Robotic Platforms
Model Predictive Control (MPC) has become a popular framework in embedded control for high-performance autonomous systems. However, to achieve good control performance using MPC, an accurate dynamics model is key. To maintain real-time operation, the dynamics models used on embedded systems have been limited to simple first-principle models, which substantially limits their representative power. In contrast to such simple models, machine learning approaches, specifically neural networks, have been shown to accurately model even complex dynamic effects, but their large computational complexity hindered combination with fast real-time iteration loops. With this work, we present Real-time Neural MPC , a framework to efficiently integrate large, complex neural network architectures as dynamics models within a model-predictive control pipeline. Our experiments, performed in simulation and the real world onboard a highly agile quadrotor platform, demonstrate the capabilities of the described system to run learned models with, previously infeasible, large modeling capacity using gradient-based online optimization MPC. Compared to prior implementations of neural networks in online optimization MPC we can leverage models of over 4000 times larger parametric capacity in a 50 Hz real-time window on an embedded platform. Further, we show the feasibility of our framework on real-world problems by reducing the positional tracking error by up to 82% when compared to state-of-the-art MPC approaches without neural network dynamics
Rapid determination of general cell status, cell viability, and optimal harvest time in eukaryotic cell cultures by impedance flow cytometry
The determination of cell viability is essential to many areas of life sciences and biotechnology. Typically, cell viability measurements are based on the optical analysis of stained cells, which requires additional labeling steps and is hard to implement online. Frequency-dependent impedance flow cytometry (IFC) provides a label-free, fast, and reliable alternative to determine cell viability at the single cell level based on the Coulter principle. Here, we describe the application of IFC to eukaryotic cell cultures and compare the results to commonly used staining methods. Yeast cell parameters were assessed in normal and heat-inactivated cells as well as in alcoholic fermentation and long-term batch cultures providing a precise and fast determination of the cell viability and further quantitative measures of the cell culture status. As an important new application, we have investigated recombinant protein production in the widely used baculovirus insect cell expression system. The IFC analysis revealed the presence of a subpopulation of cells, which correlates with the protein expression yield, but it is not detectable with conventional optical cell counters. We tentatively identify this subpopulation as cells in the late phase of infection. Their detection can serve as a predictor for the optimal time point of harvest. The IFC technique should be generally applicable to many eukaryotic cell cultures in suspension, possibly also implemented online
The Instanton Universal Moduli Space of N=2 Supersymmetric Yang-Mills Theory
We use the recursive structure of the compactification of the instanton
moduli space of N=2 Super Yang-Mills theory with gauge group SU(2), to
construct, by inductive limit, a universal moduli space which includes all the
multi-instanton moduli spaces. Furthermore, with the aim of understanding the
field theoretic structure of the strong coupling expansion, we perform the
Borel sum which acts on the parameter defining such a universal moduli space.Comment: 1+4 pages, LaTeX. Minor changes. To appear in Phys. Lett.
Sustained Benefit Lasting One Year from T4 Instead of T3-T4 Sympathectomy for Isolated Axillary Hyperhidrosis
INTRODUCTION: Level T4 video-assisted thoracoscopic sympathectomy proved superior to T3-T4 treatment for controlling axillary hyperhidrosis at the initial and six-month follow-ups of these patients. OBJECTIVE: To compare the results of two levels of sympathectomy (T3-T4 vs. T4) for treating axillary sudoresis over one year of follow-up. METHODS: Sixty-four patients with axillary hyperhidrosis were randomized to denervation of T3-T4 or T4 alone and followed prospectively. All patients were examined preoperatively and were followed postoperatively for one year. Axillary hyperhidrosis treatment was evaluated, along with the presence, location, and severity of compensatory hyperhidrosis and self-reported quality of life. RESULTS: According to patient reports after one year, all cases of axillary hyperhidrosis were successfully treated by surgery. There were no instances of treatment failure. After six months, compensatory hyperhidrosis was present in 27 patients of the T3-T4 group (87.1%) and in 16 patients of the T4 group (48.5%). After one year, all T3-T4 patients experienced some degree of compensatory hyperhidrosis, compared to only 14 patients in the T4 group (42.4%). In addition, compensatory hyperhidrosis was less severe in the T4 patients (p < 0.01). Quality of life was poor before surgery, and it improved in both groups at six months and one year of follow-up (p = 0.002). There were no cases of mortality, no significant postoperative complications, and no need for conversion to thoracotomy in either group. CONCLUSION: Both techniques were effective for treating axillary hyperhidrosis, but the T4 group showed milder compensatory hyperhidrosis and greater patient satisfaction at the one-year follow-up
The Corona Immunitas Digital Follow-Up eCohort to Monitor Impacts of the SARS-CoV-2 Pandemic in Switzerland: Study Protocol and First Results
Objectives: To describe the rationale, organization, and procedures of the Corona Immunitas Digital Follow-Up (CI-DFU) eCohort and to characterize participants at baseline. Methods: Participants of Corona Immunitas, a population-based nationwide SARS-CoV-2 seroprevalence study in Switzerland, were invited to join the CI-DFU eCohort in 11 study centres. Weekly online questonnaires cover health status changes, prevention measures adherence, and social impacts. Monthly questionnaires cover additional prevention adherence, contact tracing apps use, vaccination and vaccine hesitancy, and socio-economic changes. Results: We report data from the 5 centres that enrolled in the CI-DFU between June and October 2020 (covering Basel City/Land, Fribourg, Neuchâtel, Ticino, Zurich). As of February 2021, 4636 participants were enrolled and 85,693 weekly and 27,817 monthly questionnaires were collected. Design-based oversampling led to overrepresentation of individuals aged 65+ years. People with higher education and income were more likely to enroll and be retained. Conclusion: Broad enrolment and robust retention of participants enables scientifically sound monitoring of pandemic impacts, prevention, and vaccination progress. The CI-DFU eCohort demonstrates proof-of-principle for large-scale, federated eCohort study designs based on jointly agreed principles and transparent governance.
Keywords: SARS-CoV-2; digital follow-up; eCohort; population-based study; prevention; public health surveillanc
Особенности обогащения углей с большим содержанием легкоразмокаемой породы
Наведені результати дослідження технологічних процесів при збагаченні вугілля з великим вмістом породи, яка легко розмокає, умовах ЦЗФ "Павлоградська". Визначенні особливості ведення технологічних процесів підготовки машинних класів важкосередовищної сепарації. відсадки, флотації. обробки шламових продуктів та сушіння дрібного концентрату, які відрізняються від загальноприйнятих.Приведены результаты исследований технологический процессов при обогащении углей с большим содержанием легкоразмокаемой породы в условиях ЦОФ "Павлоградская". Определены особенности ведения технологических процессов подготовки машинных классов, тяжелосредной сепарации, отсадки, флотации, обработки шламовых продуктов и сушки мелкого концентрата, которые отличаются от общепринятых
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