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Mixtures of Distributions and Volatility

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Journal of Statistical Science and Application 2016年第4期4卷 179-189页

作者： juan carlos abril Maria de las Mercedes abril carlos Ismael Martinez Universidad Nacional de Tucuman. Facultad de Ciencias Economicas and Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET). Tucuman. Argentina.

Using Monte Carlo methods we generate time series with the following features： a） series with distributions that are the mix of two normal distributions with different variances, b） series that satisfy volatility models, c） series that satisfy an AR（1） model but with contaminated errors that follow the same distribution as the mixes given in a） and d） series that follow the same distribution as the mixes given in a） but with conditional heterocedasticity. From the analysis we see that it is difficult to identify in practical situations the real generating process of the series. In fact, the processes that come from distribution mixes have many similar characteristics to the ones that satisfy the volatility scheme. We use the corresponding theoretical considerations and also the usual tools in the identifying process of any time series; that is, series graphs, histograms, the corresponding sampling distributions, correlograms and partial correlograms.

关键词： Autoregression Contaminated errors Distribution mixes AR(1) models ARCH models Volatility.

The Multivariate Saddlepoint Approximation to the Distribution of Estimators： A General Approach

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Journal of Mathematics and System Science 2016年第2期6卷 53-59页

作者： juan carlos abril Maria de las Mercedes abril carlos I. Martinez Universidad Nacional de Tucum6n and Consejo Nacional de lnvestigaciones Cientifieas y Técnicas (CONICET). Tucumán Argentina.

We develop the theory of multivariate saddlepoint approximations. Our treatment differs from the one in Barndorff-Nielsen and Cox （1979, equation （4.7）） in two aspects： 1） our results are satisfied for random vectors that are not necessarily sums of independent and identically distributed random vectors, and 2） we consider that the sample is taken from any distribution, not necessarily a member of the exponential family of densities. We also show the relationship with the corresponding multivariate Edgeworth approximations whose general treatment was developed by Durbin in 1980, emphasizing that the basic assumptions that support the validity of both approaches are essentially similar.

关键词： Approximate distributions Asymptotic expansions Edgeworth approximations Saddlepoint approximations.

The potential of starch-chitosan blends with poloxamer for the preparation of microparticles by spray-drying

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Particuology 2024年第6期89卷 1-10页

作者： juan Enrique Barranco-García Carolina Caicedo Enrique Javier Jiménez-Regalado carlos Espinoza-González Graciela Morales Rocio Yaneli Aguirre-Loredo abril Fonseca-García Tecnológico Nacional de México/Instituto Tecnológico de Oaxaca Departamento de Química y BioquímicaAvenida Ing.Víctor Bravo Ahuja No.125Esquina Calzada Tecnológico68030OaxacaMexico Faculty of Engineering Unidad Central del Valle del Cauca(UCEVA)Carrera 17a 48-144763022TuluáColombia Centro de Investigación en Química Aplicada(CIQA) Blvd.Enrique Reyna Hermosillo 14025294SaltilloCoahuilaMexico Investigadoras por México CONAHCYT-CIQA Av.Insurgentes Sur 1562Col.Crédito Constructor03940Alcaldía Benito JuárezCDMXMexico

Using biopolymers as wall materials in spray drying poses challenges,particularly in attaining flowability and thermal stability among their physicochemical *** paper addresses these challenges by preparing microparticles using a blend of starch–chitosan and a poloxamer,commercially named Pluronic®*** aimed to elucidate the effects of varying poloxamer concentrations on the resulting particles through the spray drying *** with a poloxamer concentration of 3%(w/v)demonstrated a notably higher yield,especially when compared to those with 0%and 1%*** with 3%and 5%(w/v)poloxamer displayed a narrower particle size distribution,with the 3%blend showing a superior yield attributed to arrangements of blend components that improve flowability.X-ray diffraction analysis showcased the characteristic peaks of A-type starch form,with shifts suggesting enhanced interactions between *** with increased poloxamer content showed elevated thermal degradation temperatures,with the 3%blend registering a significant rise,opening avenues for encapsulating heat-sensitive *** study primarily focuses on the preparation and basic characterization of *** underscores the potential of blends with optimal poloxamer concentrations in microencapsulation,emphasizing further research to harness their capabilities thoroughly.

关键词： Biopolymer Starch Chitosan Pluronic®F127 Microparticles Spray drying

Brent *** Texas Intermediate in the US petro derivatives price formation

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Petroleum Science 2024年第1期21卷 729-739页

作者： Alejandro Almeida Antonio A.Golpe juan Manuel Martín-Alvarez Jose carlos Vides Universidad Internacional de La Rioja Department of Quantitative Methods for Economics and BusinessLa RiojaSpain University of Huelva Department of Economics and Centro de Estudios Avanzados en FisicaMatematicas y Computacion and ICEIHuelvaSpain Complutense University of Madrid Department of Applied and Structural Economics and History and ICEIMadridSpain

In this paper,we apply the spatial panel model to explore the relationship between the dynamic of two types of crude oil prices(WTI and Brent crude oil)and their refined products over *** the turbulent months of 2011,when Cushing Oklahoma had reached capacity and the crude oil export ban removal in 2015 as breakpoints,we apply this method both in the full sample and the three resultant ***,results suggest our results show that both WTI and Brent display very similar behaviour with the refined ***,when attending to each regime,results derived from the first and third regimes are quite similar to the full sample ***,during the second regime,Brent crude oil became the benchmark in the petrol market,and it influenced the distillate ***,our model can let us determine the price-setters and price-followers in the price formation mechanism through refined *** results possess important considerations to policymakers and the market participants and the price formation.

关键词： Crude oil prices Spatial panel model Refined products Price formation

Novel insights into D-Pinitol based therapies:a link between tau hyperphosphorylation and insulin resistance

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Neural Regeneration Research 2024年第2期19卷 289-295页

作者： Dina Medina-Vera Antonio Jesús López-Gambero juan Antonio Navarro carlos Sanjuan Elena Baixeras juan Decara Fernando Rodríguez de Fonseca Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina-IBIMA Plataforma BIONAND UGC Salud MentalMálagaSpain Facultad de Ciencias Universidad de MálagaMálagaSpain CIBER Enfermedades Cardiovasculares(CIBERCV) Hospital Universitario Virgen de la VictoriaUGC del CorazónMálagaSpain University of Bordeaux INSERMNeurocentre MagendieBordeauxFrance Euronutra S.L.Calle Johannes Kepler MálagaSpain Departamento de Bioquímica y Biología Molecular Facultad de MedicinaUniversidad de MálagaMálagaSpain

Alzheimer’s disease is a neurodegenerative disorder characterized by the amyloid accumulation in the brains of patients with Alzheimer’s *** pathogenesis of Alzheimer’s disease is mainly mediated by the phosphorylation and aggregation of tau *** the multiple causes of tau hyperphosphorylation,brain insulin resistance has generated much attention,and inositols as insulin sensitizers,are currently considered candidates for drug *** present narrative review revises the interactions between these three elements:Alzheimer’s disease-tau-inositols,which can eventually identify targets for new disease modifiers capable of bringing hope to the millions of people affected by this devastating disease.

关键词： Alzheimer’s disease cyclin-dependent kinase 5 diabetes D-Pinitol inositols insulin resistance kinases phosphorylation PI3K/Akt tau

MAVS Antagonizes Human Stem Cell Senescence as a Mitochondrial Stabilizer

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Research 2024年第2期2023卷 239-257页

作者： Cui Wang Kuan Yang Xiaoqian Liu Si Wang Moshi Song juan carlos Izpisua Belimonte Jing Qu Guang-Hui Liu Weiqi Zhang CAS Key Laboratory of Genomic and Precision Medicine Beijng Institute of GenomicsChinese Academy of Sciences and China National Center for BioinformationBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Sino-Danish College University of Chinese Academy of SciencesBeijing 101408China State Key Laboratory of Stem Cell and Reproductive Biology Institute of ZoologyChinese Academy of SciencesBeijing 100101China Institute for Stem Cell and Regeneration Chinese Academy of Sciences Beijing 100101China Beijing Institute for Stem Cell and Regenerative Medicine Bejing 100101China Advanced Innovation Center for Human Brain Protection National Clinical Research Center for Geriatric DisordersXuanwu Hospital Capital Medical UniversityBeijing 100053China State Key Laboratory of Membrane Biology Institute of ZoologyChinese Academy of SciencesBeijing 100101China Altos Labs Inc.San DiegoCA 94022USA

Mitochondrial dysfunction is a hallmark feature of cellular senescence and organ ***,we asked whether the mitochondrial antiviral signaling protein(MAVS),which is essential for driving antiviral response,also regulates human stem cell *** answer this question,we used CRISPR/Cas9-mediated gene editing and directed differentiation techniques to generate various MAVS-knockout human stem cell *** found that human mesenchymal stem cells(hMSCs)were sensitive to MAVS deficiency,as manifested by accelerated senescence *** uncovered that the role of MAVS in maintaining mitochondrial structural integrity and functional homeostasis depends on its interaction with the guanosine triphosphatase optic atrophy type 1(OPA1).Depletion of MAVS or OPA1 led to the dysfunction of mitochondria and cellular senescence,whereas replenishment of MAVS or OPA1 in MAVS-knockout hMSCs alleviated mitochondrial defects and premature senescence *** together,our data underscore an uncanonical role of MAVS in safeguarding mitochondrial homeostasis and antagonizing human stem cell senescence.

关键词： CRISPR/Cas9 homeostasis Mitochondrial

A Cultural Catalyst--Bulgarian Sinologist brings Chinese culture closer to Mexicans

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Beijing Review 2024年第17期67卷 42-43页

作者： juan carlos Aguilar 不详

At the National School of Languages,Linguistics and Translation(ENALLT)at the National Autonomous University of Mexico in the country's capital of Mexico City,Sinologist Radina Dimitrova is recognized by both students... 详细信息

关键词： closer culture Catalyst

Present and future of new systemic therapies for early and intermediate stages of hepatocellular carcinoma

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World Journal of Gastroenterology 2024年第19期30卷 2512-2522页

作者： juan Jose Urquijo-Ponce carlos Alventosa-Mateu Mercedes Latorre-Sánchez Inmaculada Castelló-Miralles Moisés Diago Hepatology Unit Department of Digestive Diseases Consorcio Hospital General Universitario of ValenciaValencia 46014Spain

Hepatocellular carcinoma(HCC)is a high mortality neoplasm which usually appears on a cirrhotic *** therapeutic arsenal and subsequent prognostic outlook are intrinsically linked to the HCC stage at *** the current deployment of treatments with curative intent(liver resection/local ablation and liver transplantation)in early and intermediate stages,a high rate of HCC recurrence persists,underscoring a pivotal clinical *** systemic therapies(ST),particularly immunotherapy,have demonstrate promising outcomes in terms of increase overall survival,but they are currently bound to the advanced stage of *** review provides a comprehensive analysis of the literature,encompassing studies up to March 10,2024,evaluating the impact of novel ST in the early and intermediate HCC stages,specially focusing on the findings of neoadjuvant and adjuvant regimens,aimed at increasing significantly overall survival and recurrence-free survival after a treatment with curative *** also investigate the potential role of ST in enhancing the downstaging rate for the intermediate-stage HCC initially deemed ineligible for treatment with curative ***,we critically discuss about the current relevance of the results of these studies and the encouraging future implications of ST in the treatment schedules of early and intermediate HCC stages.

关键词： Hepatocellular carcinoma Early stage Intermediate stage Neoadjuvant Adjuvant Systemic therapy

Building Tax Capacity in Developing Countries

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Belt and Road Initiative Tax Journal 2024年第1期 60-69页

作者： Cindy Negus juan carlos Benitez Revenue Administration 1 Division Fiscal Affairs Department International Monetary Fund Tax Policy 2 Division Fiscal Affairs Department International Monetary Fund

Building tax capacity is central to the role of government in achieving the sustainable development goals,addressing climate change,and ensuring debt *** progress in revenue mobilization,there is still a large unmet tax potential in low-income developing *** tax capacity requires a firm commitment to building institutions that govern the tax system and manage tax reform,and to improving the design of core *** enhance understanding,this article provides a synopsis of why improving tax capacity is important and contains insights on trends in revenue mobilization,how to strengthen tax policy and the role of supporting ***,it explores the importance of a sound legal framework for tax certainty,which plays a crucial role in shaping investment choices and can significantly affect economic growth.

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