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Non-Linear Dependence in Oil Price Behavior

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Journal of Mathematics and System Science 2012年第2期2卷 110-118页

作者： Semei Coronado ramirez Leonardo Gatica Arreola Mauricio ramirez Grajeda Department of Quantitative Methods University of Guadalajara Zapopan Jalisco 45100 Mexico Department of Economics University of Guadalajara Zapopan Jalisco 45100 Mexico

In this paper, the authors analyze the adequacy of GARCH-type models to analyze oil price behavior by applying two types of non-parametric tests, the Hinich portmanteau test for non-linear dependence and a frequency-dominant test of time reversibility, the reverse test based on the bispectrum, to explore the high-order spectrum properties of the Mexican oil price series. The results suggest strong evidence of a non-linear structure and time irreversibility. Therefore, it does not comply with the i.i.d （independent and identically distributed） property. The non-linear dependence, however, is not consistent throughout the sample period, as indicated by a windowed test, suggesting episodic nonlinear dependence. The results imply that GARCH models cannot capture the series structure.

关键词： Bispcctrum time reversibility nonlinearity asymmetry oil price.

Qualitative Perspective of Audit Materiality： Empirical Evidence in Mexico and Colombia

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Chinese Business Review 2012年第10期11卷 864-872页

作者： Sergio Ivan ramirez Cacho Martin Alvarez Ochoa Maricela ramirez University of Colima Manzanillo Mexico University of Boyaca Tunja Colombia

Our contribution analyzes the process of convergence with the International Standards of Audit （ISAs）, particularly those that regulate the concept of materiality in Mexico and Colombia. Between other results, across a survey, it is demonstrated why the effective use of the factors that emerge of his qualitative slope can favor the quality of the financial information that publish the audited companies, the usefulness and the comprehensibility of the report of opinion. In general, the reliability, transparency, and relevancy of the financial statements will meet potentially favored with the strict application of these major and better normative instruments.

关键词： qualitative perspective materiality financial statements audit materiality International Federation ofAccountants (IFAC)

Effectiveness of statins *** on reducing postprandial hypertriglyceridemia in dyslipidemic population:A systematic review and network meta-analysis

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Journal of Sport and Health Science 2022年第5期11卷 567-577页

作者： Laura Alvarez-Jimenez Alfonso Moreno-Cabanas Miguel ramirez-Jimenez Felix Morales-Palomo Juan FOrtega Ricardo Mora-Rodriguez Exercise Physiology Lab at Toledo Sports Science DepartmentUniversity of Castilla-La ManchaToledo 45004Spain

Background:Individuals at risk of suffering cardiovascular disease(CVD) present with larger increases in blood trigyceride(TG) concentration after a high-fat meal than do healthy *** postprandial hypertriglyceride levels are an independent risk factor for *** of statins and a bout of prolonged exercise are both effective in lowering postprandial hypertriglyceride *** aimed to evaluate the comparative effectiveness of statins vs.a bout of aerobic exercise in reducing fasting and postprandial TG(PPTG) concentrations in indiv、duals at high nsk of developing ***:Thirty-seven sltudies from a systematic literature search of the PubMed,EMBASE,and Cochrane databases were included in this *** selected studies conducted trials involving statin therapy(n=20) or a bout of aerobic exercise(n=19) and measured their impact on PPTG levels as the *** studies analyzed both treatments and were included in *** meta-analysis was constructed using a random-effects model to calculate the mean difference(MD).The Student t test was used to compare the data sets for statins ***:Overall,statin and exercise interventions showed similar reductions in PPTG levels,with an MD of-0.65 mmol/L for statins(95% confidence interval(95%CI):-0.54 to-0.77;p <0.001) and-0.46 mmol/L for exercise(95%CI:-0.21 to-0.71;p <0.01).However,statins lowered fasting TG levels more than exercise(MD=-1.54 mmol/L,95%CI:-2.25 to-0.83;p=0.009).Conclusion:Although aerobic exercise is effective in lowering blood TG levels,statins seem to be more efficient,especially in the fasted state.A combination of exercise and statins might reveal a valuable approach to the treatment and prevention of *** studies are required to determine the underlying mechanisms and the possible additive effects of these interventions.

关键词： Aerobic exercise Cardiovascular disease Hydroxymethylglutaryl-CoA reductase inhibitor Meta-analysis Metabolic syndrome

Nickel-based cerium zirconate inorganic complex structures for CO_(2)valorisation via dry reforming of methane

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Journal of Environmental Sciences 2024年第6期140卷 12-23页

作者： Juan Luis Martín-Espejo Loukia-Pantzechroula Merkouri Jesús Gándara-Loe José Antonio Odriozola Tomas ramirez Reina Laura Pastor-Pérez Department of Inorganic Chemistry and Material Sciences Institute of Seville University of Seville-CSICSeville 41092Spain Department of Chemical and Process Engineering University of SurreyGuildford GU27XHUnited Kingdom

The increasing anthropogenic emissions of greenhouse gases(GHG)is encouraging extensive research in CO_(2)*** reforming of methane(DRM)depicts a viable strategy to convert both CO_(2)and CH4into syngas,a worthwhile chemical *** the different active phases for DRM,the use of nickel as catalyst is economically favourable,but typically deactivates due to sintering and carbon *** stabilisation of Ni at different loadings in cerium zirconate inorganic complex structures is investigated in this work as strategy to develop robust Ni-based DRM *** and TPR-H2analyses confirmed the existence of different phases according to the Ni loading in these ***,superficial Ni is observed as well as the existence of a CeNiO_(3)perovskite *** catalytic activity was tested,proving that 10 wt.%Ni loading is the optimum which maximises *** catalyst was also tested in long-term stability experiments at 600and 800℃in order to study the potential deactivation issues at two different *** 600℃,carbon formation is the main cause of catalytic deactivation,whereas a robust stability is shown at 800℃,observing no sintering of the active phase evidencing the success of this strategy rendering a new family of economically appealing CO_(2)and biogas mixtures upgrading catalysts.

关键词： CO_(2)conversion Dry reforming of methane Nickel catalysts Pyrochlore Cerium zirconate

Undergraduate Design and Analysis of a LEED Certified Building

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Journal of Civil Engineering and Architecture 2022年第5期16卷 227-234页

作者： Lance Narcida Madison O’Dell Mynor Pacheco carlos Perla Victor ramirez Damian Sanchez Jillian Shoemaker Louisa Songco Tadeh Zirakian David Boyajian Department of Civil Engineering and Construction Management California State UniversityNorthridgeCAU.S.A.

In this technical and educational research endeavor, a diverse group of civil engineering students took on the role of creating the means and methods of producing a successful building design. Architectural, structural, and environmental designs were primarily performed. This was followed by detailed cost analysis with the intent of providing a realistic cost comparison by pricing the intended building, using traditional material and typical building methods, versus pricing the building using recycled material and new present-day technology. Some green features needed to achieve a LEED (Leadership in Energy and Environmental Design) gold certification were considered and applied. It is shown that producing a green building is more costly in present circumstances;however, the additional cost due to greenification pays itself off throughout the years giving in return saving features. Even though the design of a green building comes with detailed planning and costly material, it does generate benefits for the building owner, the society, and most importantly the environment.

关键词： Structural design LEED certification green building design cost analysis engineering education

Seroepidemiology of Helicobacter pylori infection in general population in a northern Mexican city

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Health 2014年第1期6卷 27-32页

作者： Cosme Alvarado-Esquivel Agar Ramos-Nevarez Sandra Margarita Cerrillo-Soto Lucio Martinez-ramirez carlos Alberto Guido-Arreola Fernando Arturo Munoz-Gonzalez Biomedical Research Laboratory Faculty of Medicine and NutritionJuarez University of Durango StateDurangoMexico Clinica de Medicina Familiar Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado(ISSSTE)DurangoMexico

Background: The seroepidemiology of Helicobacter pylori infection in general population in Durango City, Mexico has not been previously studied. Aims: To determine the seroprevalence of anti-H. pylori antibodies in the general population in Durango City, Mexico;and to determine socio-demographic, clinical, and behavioral characteristics of the general population associated with H. pylori seropositivity. Methods: The prevalence of anti-H. pylori IgG antibodies was examined in 345 individuals in Durango City, Mexico, using enzyme-linked immunoassays. Socio-demographic, clinical, and behavioral characteristics of the general population associated with H. pylori seroprevalence were also investigated. Results: In total, 231 (67%) of the 345 participants (mean age, 45.3. ± 17.5 years) had H. pylori IgG antibodies, 146 (63.2%) of whom had H. pylori IgG antibody levels higher than 100 U/mL. Both H. pylori seroprevalence and antibody levels increased significantly with age, and were similar in males and females. An increased H. pylori seroprevalence was found in subjects with low education and employed. In contrast, a low seroprevalence was found in subjects living in suburban areas. One of four subjects with gastritis symptoms had anti-H. pylori antibodies. The seroprevalence of H. pylori was significantly higher among women with abortion history than among those without such history. Multivariate analysis of behavioral variables showed that H. pylori seropositivity was negatively associated with raising farm animals (OR = 0.48;95% CI: 0.25-0.91;P = 0.02). Conclusions: In the general population studied, H. pylori seroreactivity increased significantly with age, not only in frequency but also in intensity. Residence, education, and occupation of the study population influenced the seropositivity rate of H. pylori.

关键词： Helicobacter pylori Seroprevalence General Population Epidemiology Mexico

Challenges on the Quality of Biomass Derived Products for Bringing Them into the Fuels Market

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Journal of Energy and Power Engineering 2012年第3期6卷 321-328页

作者： Magdalena ramirez Vicente Sanchez Product Quality KiOR Inc. Pasadena TX 77507 USA

US EPA recently issued the final definition for a renewable fuel establishes rule for the revised Renewable Fuel Standard RFS the compliance for each part of its name：（i） to II （Renewable Fuel Standard）. The main be a fuel and （ii） to be produced from renewable biomass. This paper addresses the challenges faced by biomass derived fuels on meeting the specifications of those fuels （gasoline, diesel and heating oil）. Biomass-derived products contain oxygenates, some of which might enhance certain fuel specifications, but some others may have deteriorating effects. On directly derived from biomass pyrolysis have been demonstrated to the basis of available data published in the literature, the fuels be far from the concept of ＂substantially similar＂ transportation fuels. Upgrading is required to convert pyrolysis products into fuels that meet specifications. The economical viability of upgrading still faces confirmation, and imposes several technical challenges for truly attractive cost-effective approaches.

关键词： Biomass-derived fuels ASTM specifications quality upgrading RFS II.

A techno-economic and life cycle assessment for the production of green methanol from CO_(2): catalyst and process bottlenecks

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Journal of Energy Chemistry 2022年第5期31卷 255-266页

作者： Tomas Cordero-Lanzac Adrian ramirez Alberto Navajas Lieven Gevers Sirio Brunialti Luis MGandía Andrés T.Aguayo S.Mani Sarathy Jorge Gascon Department of Chemical Engineering University of the Basque Country(UPV/EHU)PO Box 64448080 BilbaoSpain King Abdullah University of Science and Technology KAUST Catalysis Center(KCC)Advanced Catalytic MaterialsThuwal 23955Saudi Arabia Department of Science Public University of Navarre(UPNA)Arrosadía Campus s/n31006 PamplonaSpain Institute for Advanced Materials and Mathematics(InaMat2) Universidad Pública de Navarra(UPNA)Edificio Jerónimo de AyanzCampus de ArrosadiaPamplona-Iruña 31006Spain King Abdullah University of Science and Technology Clean Combustion Research Center(CCRC)Thuwal 23955Saudi Arabia

The success of catalytic schemes for the large-scale valorization of CO_(2) does not only depend on the development of active,selective and stable catalytic materials but also on the overall process *** we present a multidisciplinary study(from catalyst to plant and techno-economic/lifecycle analysis)for the production of green methanol from renewable H2 and CO_(2).We combine an in-depth kinetic analysis of one of the most promising recently reported methanol-synthesis catalysts(InCo)with a thorough process simulation and techno-economic *** then perform a life cycle assessment of the simulated process to gauge the real environmental impact of green methanol production from CO_(2).Our results indicate that up to 1.75 ton of CO_(2) can be abated per ton of produced methanol only if renewable energy is used to run the process,while the sensitivity analysis suggest that either rock-bottom H2 prices(1.5$kg1)or severe CO_(2) taxation(300$per ton)are needed for a profitable methanol ***,we herein highlight and analyze some critical bottlenecks of the *** attention has been paid to the contribution of H2 to the overall plant costs,CH4 trace formation,and purity and costs of raw *** addition to providing important information for policy makers and industrialists,directions for catalyst(and therefore process)improvements are outlined.

关键词： CO_(2) Methanol Kinetic modeling Process simulation Life cycle assessment

Insulinoma after sleeve gastrectomy:A case report

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World Journal of Clinical Cases 2022年第18期10卷 6227-6233页

作者： Miry Lobaton-Ginsberg Pilar Sotelo-González Claudia ramirez-Renteria Fany Gabriela Juárez-Aguilar Aldo Ferreira-Hermosillo Facultad de Medicina Universidad Anáhuac México NorteMexico City 52786Mexico Servicio de Endocrinología Hospital de EspecialidadesCentro Médico Nacional Siglo XXIIMSSMexico City 06720Mexico Unidad de Investigación Médica en Enfermedades Endocrinas Instituto Mexicano del Seguro SocialMexico City 06720Mexico Servicio de Anatomía Patológica Hospital de Especialidades del Centro Médico Nacional Siglo XXIIMSSMexico City 06720Mexico

BACKGROUND Laparoscopic sleeve gastrectomy(LSG)has been proposed as an effective and durable treatment for severe obesity and glucose metabolism disorders,and its prevalence has increased from 5%to 37%since *** common complication after bariatric surgery is a postprandial hyperinsulinemic hypoglycemic *** rare,insulinomas can cause this state,where symptoms are more common in the fasting state;thus,evaluation of insulin secretion is *** now,there have been no reports of insulinoma after *** SUMMARY We describe the case of a 43-year-old woman who was referred to the obesity clinic 2 years after LSG was *** had symptoms of hypoglycemia predominantly in the fasting state and documented hypoglycemia of less than 30 mg/d L,which are compatible with Whipple’s ***,dumping syndrome was suspected,but after a second low fasting plasma glucose was documented,a 72-h fasting test was performed that tested *** tomography and endoscopic ultrasound were performed,identifying the presence of a homogeneous hypoechoic semioval tumoral lesion in the *** diagnosis was compatible with *** laparoscopic enucleation of the insulinoma,the symptoms and hypoglycemia *** histopathological report described a well-differentiated grade 2 neuroendocrine tumor with positive chromogranin and synaptophysin and Ki67 immunopositivity in 4%of the neoplastic *** Insulinoma after LSG is a rare condition,and clinicians must be aware of it,especially if the patient has hypoglycemic symptoms during the fasting state.

关键词： Insulinoma Hypoglycemia Bariatric surgery Glucagon-like peptide 1 amide Neuroendocrine tumors Case report