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PARALLEL STOCHASTIC NEWTON METHOD

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Journal of Computational Mathematics 2018年第3期36卷 404-425页

作者： Mojmir Mutny peter Richtarik Department of Informatics ETH Zurich Zurich Switzerland School of Mathematics University of Edinburgh Edinburgh ETH9 3FD UK Computer Electrical and Mathematical Sciences & Engineering Department KA UST Saudi Arabia

We propose a parallel stochastic Newton method （PSN） for minimizing unconstrained smooth convex functions. We analyze the method in the strongly convex case, and give conditions under which acceleration can be expected when compared to its serial counterpart. We show how PSN can be applied to the large quadratic function minimization in general, and empirical risk minimization problems. We demonstrate the practical efficiency of the method through numerical experiments and models of simple matrix classes.

关键词： Optimization Parallel methods Newton's method Stochastic algorithms.

Flow frictional characteristics of microencapsulated phase change material suspensions flowing through rectangular minichannels

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Science China(Technological Sciences) 2006年第4期49卷 445-456页

作者： Frank Dammel peter Stephan Chair of Technical Thermodynamics Darmstadt University of Technology Germany

An experimental investigation was conducted on the laminar flow frictional characteristics of suspensions with microencapsulated phase change material (MEPCM) in water flowing through rectangular copper minichannels. The MEPCM was provided at an average particle size of 4.97 μm, and was mixed with distilled water to form suspen- sions with various mass concentrations ranging from 0 to 20%. The experiment was per- formed to explore the effect of MEPCM mass concentration on friction factor and pressure drop in the minichannels. The Reynolds number ranged from 200 to 2000 to provide laminar and transitional flows. It was found that the experimental data for the suspensions with 0 and 5% concentration agree well with the existing theoretical data for an incom- pressible, fully developed, laminar Newtonian flow. For the suspensions with mass con- centrations higher than 10%, there is an obvious increase in friction factor and pressure drop in comparison with laminar Newtonian flow.

关键词： microencapsulated phase change material suspension, friction factor, rectangular minichannel.

Target blood pressure in diabetes patients with hypertension——What is the accumulated evidence in 2011?

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2011年第8期12卷 611-623页

作者： peter M.NILSSON Department of Clinical Sciences Lund UniversityUniversity Hospital

There is overwhelming evidence that hypertension is an important risk factor for both macrovascular and microvascular complications in patients with diabetes,but the problem remains to identify appropriate goals for preventive therapies.A number of guidelines (the European Society of Cardiology (ESC)/European Association for the Study of Diabetes (EASD) 2007,the Joint National Committee (JNC)-Ⅶ 2003,the American Diabetes Association (ADA) 2011) have for example advocated a blood pressure goal of less than 130/80 mmHg,but this suggestion has been challenged by findings in recent trials and meta-analyses (2011).The European Society of Hypertension (ESH) therefore recommends a systolic blood pressure goal of "well below" 140 *** on evidence from both randomized controlled trials (hypertension optimal treatment (HOT),action in diabetes and vascular disease:preterax and diamicron MR controlled evaluation (ADVANCE),action to control cardiovascular risk in diabetes (ACCORD)) and observational studies (ongoing telmisartan alone and in combination with ramipril global endpoint trial (ONTARGET),international verapamil-trandolapril study (INVEST),treat to new targets (TNT),and the National Diabetes Register (NDR)),it has been shown that the benefit for stroke reduction remains even at lower achieved blood pressure levels,but the risk of coronary events may be uninfluenced or even increased at lower systolic blood pressure *** a recent meta-analysis,it was therefore concluded that the new recommended goal should be 130-135 mmHg systolic blood pressure for most patients with type 2 *** risk factors should also be controlled with a more ambitious strategy applied in the younger patients with shorter diabetes duration,but a more cautious approach in the elderly and frail patients with a number of vascular or non-vascular *** patients from East Asia,such as China,the stroke risk is relatively higher than the risk of coronary *** must al

关键词： Blood pressure Cardiovascular Diabetes Goal Hypertension Treatment

GUN4 Is Required for Posttranslational Control of Plant Tetrapyrrole Biosynthesis

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Molecular Plant 2009年第6期2卷 1198-1210页

作者： Enrico peter Bernhard Grimm Institute of Biology/Plant Physiology Humboldt University Philippstr. 13 Building 12 D 10115 Berlin Germany

In aerobic photosynthetic organisms, GUN4 binds the chlorophyll intermediates protoporphyrin and Mg protoporphyrin, stimulates Mg chelatase activity, and is implicated in plastidic retrograde signaling. GUN4 expression is most abundant in young and greening tissues and parallels the activity of 5-aminolevulinic acid （ALA） ALA and Mg porphyrin biosynthesis during photoperiodic growth. We explored function and mode of action of GUN4 using GUN4- deficient and overexpressing plants. GUN4 overexpression leads to a general activation of the enzymes of chlorophyll biosynthesis. During photoperiodic growth GUN4 deficiency prevents ALA synthesis and chlorophyll accumulation. All these metabolic changes do not correlate with altered gene expression or changes of protein abundance in tetrapyrrole biosynthesis. While ALA feeding fails to compensate GUN4 deficiency during light-dark growth, this approach results in chlorophyll accumulation under continuous dim light. A new model defines the involvement of GUN4 in posttranslational regulation of ALA and Mg porphyrin synthesis, to sustain chlorophyll synthesis, namely under varying environmental conditions.

关键词： Tetrapyrrole biosynthesis chlorophyll Mg porphyrin branch photo-oxidation chloroplasts

USP20 links feeding-induced cholesterol synthesis and energy expenditure

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Science China(Life Sciences) 2021年第2期64卷 337-338页

作者： Xu Xiao peter Tontonoz Department of Pathology and Laboratory Medicine and Department of Biological Chemistry University of CaliforniaLos AngelesCA 90095USA

Processes that regulate energy expenditure have been the subject of intense study in recent years,both for their physiological importance and for their potential to be targeted for the treatment of metabolic *** novo ... 详细信息

关键词： synthesis energy steps

A product version of the Hilton-Milner-Frankl theorem

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Science China Mathematics 2024年第2期67卷 455-474页

作者： peter Frankl Jian Wang Alfréd Rényi Institute of Mathematics Hungarian Academy of SciencesBudapest H-1053Hungary Department of Mathematics Taiyuan University of TechnologyTaiyuan 030024China

Two families F and G of k-subsets of {1, 2,..., n} are called non-trivial cross t-intersecting if|F ∩ G|≥t for all F ∈ F, G ∈ G and | ∩ {F : F ∈ F}| < t, | ∩ {G : G ∈ G}| < t. In the present paper,we determine the maximum product of the sizes of two non-trivial cross t-intersecting families of k-subsets of{1, 2,..., n} for n≥4(t + 2)2k2, k≥5, which is a product version of the Hilton-Milner-Frankl theorem.

关键词： extremal set theory cross t-intersecting family product version non-trivial

Operational Wave Now- and Forecast in the German Bight as a Basis for the Assessment of Wave-Induced Hydrodynamic Loads on Coastal Dikes

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Journal of Ocean University of China 2017年第6期16卷 991-997页

作者： DREIER Norman FROHLE peter Institute of River and Coastal Engineering Hamburg University of Technology Hamburg Germany

The knowledge of the wave-induced hydrodynamic loads on coastal dikes including their temporal and spatial resolution on the dike in combination with actual water levels is of crucial importance of any risk-based early warning system. As a basis for the assessment of the wave-induced hydrodynamic loads, an operational wave now-and forecast system is set up that consists of i) available field measurements from the federal and local authorities and ii) data from numerical simulation of waves in the German Bight using the SWAN wave model. In this study, results of the hindcast of deep water wave conditions during the winter storm on 5–6 December, 2013(German name ‘Xaver') are shown and compared with available measurements. Moreover field measurements of wave run-up from the local authorities at a sea dike on the German North Sea Island of Pellworm are presented and compared against calculated wave run-up using the Eur Otop(2016) approach.

关键词： German Bight North Sea wave forecast Cosmo-Model SWAN hydrodynamic loads wave run-up EurOtop

Unfolded p53 in non-neuronal cells supports bacterial etiology of Alzheimer’s disease

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Neural Regeneration Research 2022年第12期17卷 2619-2622页

作者： peter W.French Innlanz Limited SydneyNSWAustralia

Alzheimer’s disease has proven to be largely intractable to treatment,despite years of research,and numerous trials of therapies that target the hallmarks of the disease-amyloid plaques and neurofibrillary *** etiology of Alzheimer’s disease remains *** is a growing body of evidence for an infectious trigger of Alzheimer’s disease,and,in particular,the focus has been on the oral pathogen Porphyromonas gingivalis(***).Reports of the expression of a misfolded form of p53 in non-neuronal cells(fibroblasts,peripheral blood mononuclear cells,and B cells)and serum,which appears several years before clinical symptoms manifest,may provide further support for the role of bacteria in general,and *** in particular,in the initiation of the *** review presents a model of the pathway from initial oral infection with *** to amyloid plaque formation and neuronal degeneration,via the steps of chronic periodontitis;secretion of the inflammagens lipopolysaccharide and gingipains into the bloodstream;induction of an inflammatory response in both peripheral cells and tissues;disruption of the blood-brain barrier,and entry into the central nervous system of the inflammagens and the *** bacteria *** this model,the misfolded p53(or“unfolded p53”;up53)is induced in non-neuronal cells and upregulated in serum as a result of oxidative stress due to lipopolysaccharide from ***53 is therefore a potential biomarker for early diagnosis of the presence of a causative agent of Alzheimer’s *** dental hygiene and aggressive antibiotic treatment may prevent the patient progressing to clinical Alzheimer’s disease if serum up53 is detected at this pre-symptomatic stage.

关键词： Alzheimer’s disease gingipains lipopolysaccharide P.gingivalis periodontitis unfolded p53

Quantum corrections for Boltzmann equation

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Science China(Physics,Mechanics & Astronomy) 2008年第9期51卷 1229-1239页

作者： M. Levy peter Department of Physics New York University

We present the lowest order quantum correction to the semiclassical Boltzmann distribution function,and the equation satisfied by this correction is given. Our equation for the quantum correction is obtained from the conventional quantum Boltzmann equation by explicitly expressing the Planck constant in the gradient approximation,and the quantum Wigner distribution function is expanded in pow-ers of Planck constant,too. The negative quantum correlation in the Wigner dis-tribution function which is just the quantum correction terms is naturally singled out,thus obviating the need for the Husimi’s coarse grain averaging that is usually done to remove the negative quantum part of the Wigner distribution function. We also discuss the classical limit of quantum thermodynamic entropy in the above framework.

关键词： quantum Boltzmann equation Wigner distribution function quantum correction