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Optimal Control of Service Rates of Discrete-Time(s,Q)Queueing-Inventory Systems with Finite Buffer

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Journal of Systems Science and Systems engineering 2024年第3期33卷 261-280页

作者： L.Iniya B.Sivakumar g.Arivarignan School of Mathematics Madurai Kamaraj UniversityMaduraiTamilnaduIndia Department of Statistics Manonmaniam Sundaranar UniversityTirunelveliTamilnaduIndia

This article,we develop an optimal policy to control the service rate of a discrete time queueing-inventory system with finite *** customers arrive according to a Bernoulli process and the service time for the customers are *** the buffer size attains its maximum,any arriving new customers are considered to be *** customers are served one by one according to FCFS rule and each customers request random number of *** inventory is replenished according to a(s,Q)inventory policy with geometric lead *** main objectives of this article are to determine the service rates to be employed at each slot so that the long run expected cost rate is minimized for fixed inventory level and fixed buffer size and to minimize the expected waiting time for a fixed inventory level and fixed buffer *** problems are modelled as Markov decision *** establish the existence of a stationary policy and employ linear programming method to find the optimal service *** provide some numerical examples to illustrate the behaviour of the model.

关键词： Queueing-inventory system discrete time batch demand-Markov decision process

The great catastrophe: causes of the Permo-Triassic marine mass extinction

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National Science Review 2024年第1期11卷 37-50页

作者： Paul B.Wignall David P.g.Bond School of earth & environment University of Leeds School of environmental Sciences University of Hull

The marine losses during the Permo-Triassic mass extinction were the worst ever experienced. All groups were badly affected, especially amongst the benthos(e.g. brachiopods, corals, bryozoans, foraminifers,ostracods). Planktonic populations underwent a fundamental change with eukaryotic algae being replaced by nitrogen-fixing bacteria, green-sulphur bacteria, sulphate-reducing bacteria and prasinophytes. Detailed studies of boundary sections, especially those in South China, have resolved the crisis to a ～55 kyr interval straddling the Permo-Triassic boundary. Many of the losses occur at the beginning and end of this interval painting a picture of a two-phase extinction. Improved knowledge of the extinction has been supported by numerous geochemical studies that allow diverse proposed extinction mechanisms to be studied. A transition from oxygenated to anoxic-euxinic conditions is seen in most sections globally, although the intensity and timing shows regional variability. Decreased ocean ventilation coincides with rapidly rising temperatures and many extinction scenarios attribute the losses to both anoxia and high *** kill mechanisms include ocean acidification for which there is conflicting support from geochemical proxies and, even less likely, siltation(burial under a massive influx of terrigenous sediment) which lacks substantive sedimentological evidence. The ultimate driver of the catastrophic changes at the end of the Permian was likely Siberian Trap eruptions and their associated carbon dioxide emissions with consequences such as warming, ocean stagnation and acidification. Volcanic winter episodes stemming from Siberian volcanism have also been linked to the crisis, but the short-term nature of these episodes(ecades) and the overwhelming evidence for rapid warming during the crisis makes this an unlikely cause. Finally, whilst the extinction is well studied in equatorial latitudes, a different history is found in northern Boreal latitudes

关键词： ocean anoxia ocean acidification siltation productivity collapse volcanic winter

exploring the mass gap:Black holes in green pea galaxies

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Science China(Physics,Mechanics & Astronomy) 2024年第10期67卷 170-171页

作者： James e.Rhoads School of earth and Space exploration Arizona State UniversityTempeAZ 85287USA

We know about black holes primarily on two mass scales(e.g.,see Figure 22 of ref.[1]).Supermassive black holes inhabit the centers of galaxies,where they sometimes power active galactic nuclei(AgN).Their populations can be probed through AgN surveys,tidal disruption event surveys,and(in the closest galaxies)stellar and gas dynamics in the innermost regions where the black hole dominates the gravitational potential.

关键词： galaxies tidal galactic

Non-canonical BRAF variants and rearrangements in hairy cell leukemia

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Oncology Research 2024年第9期32卷 1423-1427页

作者： STePHeN e.LANgABeeR Cancer Molecular Diagnostics St.James’s HospitalDublinD08 W9RTIreland

Hairy cell leukemia(HCL)is an uncommon mature B-cell malignancy characterized by a typical morphology,immunophenotype,and clinical *** vast majority of HCL patients harbor the canonical BRAF V600e mutation which has become a rationalized target of the subsequently deregulated RAS-RAF-MeK-MAPK signaling pathway in HCL patients who have relapsed or who are refractory to front-line ***,several HCL patients with a classical phenotype display non-canonical BRAF mutations or *** include sequence variants within alternative exons and an oncogenic fusion with the IgH *** must be taken in the molecular diagnostic work-up of patients with typical HCL but without the BRAF V600e to include investigation of these uncommon ***,functional characterization,and reporting of further such patients is likely to provide insights into the pathogenesis of HCL and enable rational selection of targeted inhibitors in such patients if required.

关键词： Hairy cell leukemia BRAF Molecular diagnostics Targeted therapy

Neutrophils in the tumor microenvironment-when a company becomes a crowd

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Cellular & Molecular Immunology 2024年第4期21卷 313-314页

作者： Zvi g.Fridlender Zvi granot Faculty of Medicine Hebrew University of JerusalemJerusalemIsrael Institute of Pulmonary Medicine Hadassah-Hebrew University Medical Center91120 JerusalemIsrael Department of Developmental Biology and Cancer Research Institute for Medical Research Israel CanadaFaculty of MedicineHebrew University91120 JerusalemIsrael

Traditionally,neutrophils are perceived as terminally differentiated cells with defined functions and limited *** is commonly believed that circulating,marginating and tissue-infiltrating neutrophils belong to the same homogeneous population and are capable of switching between these *** research has stagnated since the early 1980s,maintaining a narrow and simplistic view of their capabilities.

关键词： narrow infiltrating differentiated

Integrated Zoology calls for papers:special issue on wildlife diseases and parasitology

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Integrative Zoology 2024年第3期19卷 424-425页

作者： Nubia e.MATTA Wenhua XIONg Department of Biology Universidad Nacional de ColombiaBogotaColombia International Society of Zoological Sciences BeijingChina Institute of Zoology Chinese Academy of SciencesBeijingChina

The VI International Conference on Malaria and Other Blood Parasites of Wildlife and the III International Symposium of the Wildlife Diseases Research Network are scheduled to be held in Medellín,Colombia,from November 26 to 30 of 2024(https://***/lLW79).It will be hosted by the University of Antioquia’s Department of Biology and the Universidad Nacional de Colombia Department of Biology.

关键词： Blood Malaria diseases

Optimization of Random Feature Method in the High-Precision Regime

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Communications on Applied Mathematics and Computation 2024年第2期6卷 1490-1517页

作者： Jingrun Chen Weinan e Yifei Sun School of Mathematical Sciences and Suzhou Institute for Advanced Research Suzhou 215006JiangsuChina University of Science and Technology of China Hefei 230026AnhuiChina Center for Machine Learning Research and School of Mathematical Sciences Peking UniversityBeijing 100871China AI for Science Institute Beijing 100084China School of Mathematical Sciences Soochow UniversitySuzhou 215006JiangsuChina

Machine learning has been widely used for solving partial differential equations(PDes)in recent years,among which the random feature method(RFM)exhibits spectral accuracy and can compete with traditional solvers in terms of both accuracy and ***,the optimization problem in the RFM is more difficult to solve than those that arise in traditional *** the broader machine-learning research,which frequently targets tasks within the low-precision regime,our study focuses on the high-precision regime crucial for solving *** this work,we study this problem from the following aspects:(i)we analyze the coeffcient matrix that arises in the RFM by studying the distribution of singular values;(ii)we investigate whether the continuous training causes the overfitting issue;(ii)we test direct and iterative methods as well as randomized methods for solving the optimization *** on these results,we find that direct methods are superior to other methods if memory is not an issue,while iterative methods typically have low accuracy and can be improved by preconditioning to some extent.

关键词： Random feature method(RFM) Partial differential equation(PDe) Least-squares problem Direct method Iterative method

Olfactory immune response to SARS-CoV-2

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Cellular & Molecular Immunology 2024年第2期21卷 134-143页

作者： Sebastian A.Wellford e.Ashley Moseman Department of Integrative Immunobiology Duke University School of MedicineDurhamNCUSA

Numerous pathogens can infect the olfactory tract,yet the pandemic caused by SARS-CoV-2 has strongly emphasized the importance of the olfactory mucosa as an immune *** in the nasal passages,the olfactory mucosa is directly exposed to the environment to sense airborne odorants;however,this also means it can serve as a direct route of entry from the outside world into the *** a result,olfactotropic infections can have serious consequences,including dysfunction of the olfactory system,CNS invasion,dissemination to the lower respiratory tract,and transmission between *** research has shown that a distinctive immune response is needed to protect this neuronal and mucosal tissue.A better understanding of innate,adaptive,and structural immune barriers in the olfactory mucosa is needed to develop effective therapeutics and vaccines against olfactotropic microbes such as ***,we summarize the ramifications of SARS-CoV-2 infection of the olfactory mucosa,review the subsequent immune response,and discuss important areas of future research for olfactory immunity to infectious disease.

关键词： Mucosal immunology Neuroimmunology Infectious Disease Sars-CoV-2

Transmission of amyloid-βpathology in humans:a perspective on clinical evidence

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Neural Regeneration Research 2024年第2期19卷 390-392页

作者： Celso S.g.Catumbela Rodrigo Morales Department of Neurology McGovern Medical SchoolThe University of Texas Health Science Center at HoustonHoustonTXUSA Centro Integrativo de Biologia y Quimica Aplicada(CIBQA) Universidad Bernardo O’HigginsSantiagoChile

Transmission of misfolded amyloid-β(Aβ)aggregates between human subjects:Protein misfolding disorders are a family of diseases characterized by the accumulation of misfolded protein *** proteinaceous structures,also known as amyloids,are key drivers of fatal neurodegenerative disorders such as prion diseases,Alzheimer’s disease(AD),Parkinson’s disease,and others.

关键词： amyloid diseases Aβ