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Modeling height growth for teak plantations in Colombia using the reducible stochastic differential equation approach

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Journal of Forestry Research 2021年第3期32卷 1035-1045页

作者： sergio Orrego Cristian Montes Héctor IRestrepo Bronson PBullock Mauricio Zapata Departamento de Ciencias Forestales Universidad Nacional de ColombiaSede MedellínCra 65 No 59A-110MedellínColombia Warnell School of Forestry and Natural Resources University of GeorgiaAthensGA 30602USA

Teak(Tectona grandis L.f.)plantations are increasingly being established in tropical regions to meet a rising demand for its highly valued *** plantations have been established in the Atlantic Coastal Plain region of Colombia,a region climatically suitable for teak growth by having a monsoon climate with a unimodal precipitation *** diameter at breast height(DBH,1.3 m above ground)and mean top height,periodically measured over a 17-year period in 44 permanent sampling plots of size 0.06 and 0.10 ha,were used in this study.A stochastic differential equation(SDE),along with a Bertalanffy–Richards-type height growth model,was used to model and estimate top height growth of teak plantations in *** noise and height measurement errors were explicitly considered as the main uncertainty sources of mean top height *** best model for estimating mean top height,based on statistical performance and biological rationale,had the asymptote defined as a local parameter and the growth rate and shape specified as global *** model outperformed its counterpart that had the growth rate specified as a local parameter and asymptote and shape as global *** selected model also outperformed alternative approaches such as the mixed-effects model,generalized algebraic difference approach,and the dummy variable *** trajectories for the mean top height of teak in Colombia are biologically sound based on the measured height series and previous studies in Latin *** suggest that most of the uncertainty associated with the mean top height growth of teak plantations in Colombia was largely explained by environmental *** best estimated model using the SDE approach can be useful for predicting height growth and evaluating site productivity of teak plantations in Colombia and in neighbouring countries with biophysical characteristics similar to those where teak has been planted in Colombia.

关键词： Mean top height Stochastic differential equation Forest productivity Timber production Timberland investment

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A new approach to pedestal differentiation for soil loss estimation-a case study from a burnt area in north-central Portugal

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Journal of Forestry Research 2024年第3期35卷 45-54页

作者： Frank G.A.Verheijen Martinho A.S.Martins sergio A.Prats Jan J.Keizer Centre for Environmental and Marine Studies(CESAM) Department Environment and PlanningUniversity of Aveiro3810-193 AveiroPortugal Mediterranean Institute for Agriculture Environment and Development(MED-CHANGE)Institute for Advanced Studies and ResearchUniversity of EvoraPolo da MitraAp.947006-554 EvoraPortugal GeoBiociencias Geotecnologias E Geoengenharias(GEOBIOTEC)Department Environment and PlanningUniversity of Aveiro3810-193 AveiroPortugal

Soil pedestals have long been used as qualitative indicators of soil splash *** rangelands,plant-capped pedestals,generally grass tussocks,have also been used to quantitatively estimate soil loss since the first half of the twentieth *** agricultural lands,forests,and bad-lands,stone-capped pedestals have been used as qualitative and semi-quantitative indicators of active,'extreme'*** work has been reported on using capstone pedestal data for quantifying soil *** postulate that three distinct capstone pedestal types may be present in any given location and that a detailed analysis of a pedestal height histogram may be used to recognize their *** analysis can subsequently inform if soil loss can be reliably estimated and if so,which of the existing methods using pedestal height data will provide more accurate *** three proposed capstone pedestal types are:(1)neo-pedestals formed underneath surface stones exposed by(partial)removal of the soil surface cover;(2)endo-pedestals formed underneath stones that were buried in the soil but have been exposed by erosion;and(3)phoenix-pedestals formed underneath stones from collapsed *** the pedestal height histogram of any given location,a skew to smaller heights may indicate the existence of endo-and/or phoenix-pedestals,which may be revealed as a bi-(or tri)modal distribution when using a smaller bin *** concept was applied to a case study where soil loss had been monitored for control plots and mulched plots during a 5-year period following wildfire in a eucalypt *** measured pedestal heights and used methods to quantitatively assess soil loss from soil pedestal data in the available *** pedestal data at the end of the 5-year period under or overestimated soil loss in the control treatment,with results ranging from 60 to 115%of measured soil loss,depending on the *** is postulated that phoenix-and endo-pedestals may be a driving fact

关键词： Soil pedestals Mulch Wildfire Soil erosion Char

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Platelet rich plasma(PRP)induces autophagy in osteoblast precursor 3T3-L1

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BIOCELL 2018年第1期42卷 13-16页

作者： sergio ANDRES CARMINATI MARÍA CAROLINA BARBOSA CLAUDIO MARCELO FADER Universidad Nacional de Cuyo Facultad de OdontologíaMendozaArgentina Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET).Instituto de Histología y Embriología(IHEM) Facultad de Ciencias MédicasUniversidad Nacional de CuyoMendozaArgentina

Autophagy is an essential cellular homeostatic mechanism by which intracellular components are delivered into the lysosomes for degradation and *** has been related with a diversity of pathological or physiological dentary processes such as bone remodeling,skeletal aging,osteoclastogenesis,osteoblastogenesis and different types of oral ***-rich plasma(PRP),isolated from autologous blood,is a plasma preparation containing a higher concentration of platelets which contains numerous different growth factors and cytokines that activate several cellular signaling *** purpose of this study is to investigate the effect of PRP on autophagy stimulation in both osteoblast precursor 3T3-L1 and non-related osteoblastic *** results showed that PRP can increase the number of autophagic structures in 3T3-L1 and HeLa(cervical cancer cells)***,we have determined by Western blot a rise in the lipidated form of the autophagic protein LC3(***3-II)upon PRP *** together,our results suggest that PRP is able to induce a strongly autophagy response in osteoblast precursor and,to a lesser extent,in non-related osteoblastic cells,suggesting that PRP could be a potential therapeutic tool for some autophagy-related diseases associated with bone homeostasis.

关键词： Autophagy 3T3-L1 Platelet rich plasma Odontology

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Monounsaturated fat decreases hepatic lipid content in non-alcoholic fatty liver disease in rats

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World Journal of Gastroenterology 2007年第3期13卷 361-368页

作者： Osamah Hussein Masha Grosovski Etti Lasri sergio Svalb Uzi Ravid Nimer Assy Internal Medicine A Sieff Government Hospital Safed Israel Ort Braude College of Engineering Karmiel Israel Internal Medicine A Sieff Government Hospital Safed Israel Ort Braude College of EngineeringKarmiel Israel Department of Pathology Sieff Government Hospital Safed Israel Newe Ya'ar Research Center Ministry of AgricultureRamat Yeshai Israel Internal Medicine A Sieff Government Hospital Safed Israel Liver Unit Sieff Government Hospital Safed Israel Faculty of MedicineTechnion Israel Institute of TechnologyHaifaIsrael

AIM： To evaluate the effects of different types of dietary fats on the hepatic lipid content and oxidative stress parameters in rat liver with experimental non-alcoholic fatty liver disease （NAFLD）. METHODS： A total of 32 Sprague-Dawley rats were randomly divided into five groups. The rats in the control group （n = 8） were on chow diet （Group 1）, rats （n = 6） on methionine choline-deficient diet （MCDD）（Group 2）, rats （n = 6） on MCDD enriched with olive oil （Group 3）, rats （n = 6） on MCDD with fish oil （Group 4） and rats （n = 6） on MCDD with butter fat （Group 5）. After 2 mo, blood and liver sections were examined for lipids composition and oxidative stress parameters. RESULTS： The liver weight/rat weight ratio increased in all treatment groups as compared with the control group. Severe fatty liver was seen in MCDD ＋ fish oil and in MCDD ＋ butter fat groups, but not in MCDD and MCDD ＋ olive oil groups. The increase in hepatic triglycerides （TG） levels was blunted by 30% in MCDD ＋ olive oil group （0.59 ±0.09） compared with MCDD group （0.85 ±0.04, P 〈 0.004）, by 37% compared with MCDD ＋ fish oil group （0.95 ±0.07, P 〈 0.001）, and by 33% compared with MCDD ＋ butter group （0.09 ±0.1, P 〈 0.01）. The increase in serum TG was lowered by 10% in MCDD ＋ olive oil group （0.9 ±0.07） compared with MCDD group （1.05 ±0.06）. Hepatic cholesterol increased by 15-fold in MCDD group [（0.08 ±0.02, this increment was blunted by 21% in MCDD ＋ fish oil group （0.09 ±0.02）]. In comparison with the control group, ratio of long-chain polyunsaturated fatty acids omega-6/omega-3 increased in MCDD ＋ olive oil, MCDD ＋ fish oil and MCDD ＋ butter fat groups by 345-, 30- and 397-fold, respectively. In comparison to MCDD group （1.58 ±0.08）, hepatic MDA contents in MCDD ＋ olive oil （3.3 ±0.6）, MCDD ＋ fish oil （3.0 ±0.4）, and MCDD ＋ butter group （2.9 ±0.36） were increased by 108%, 91% and 87%, respectively （P 〈 0.004）. Hepatic paraoxonase activity decreased significantly in all treatment groups, mostly

关键词： Fatty liver Non-alcoholic steatohepatitis Dietary fat Fatty acids Methionine choline-deficient diet Insulin resistance Olive oil Oxidative stress Paraoxonase

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Small intestine bacterial overgrowth and irritable bowel syndrome-related symptoms:Experience with Rifaximin

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World Journal of Gastroenterology 2009年第21期15卷 2628-2631页

作者： sergio Peralta Claudia Cottone Tiziana Doveri Piero Luigi Almasio Antonio Craxi Operative Unit of Gastroenterology and Hepatology

AIM： TO estimate the prevalence of small intestinal bacterial overgrowth （SIBO） in our geographical area （Western Sicily, Italy） by means of an observational study, and to gather information on the use of locally active, non-absorbable antibiotics for treatment of SIBO.METHODS： Our survey included 115 patients fulfilling the Rome II criteria for diagnosis of irritable bowel syndrome （IBS）; a total of 97 patients accepted to perform a breath test with lactulose （BTLact）, and those who had a positive test, received Rifaximin （Normix , Alfa Wassermann） 1200 mg/d for 7 d; 3 wk after the end of treatment, the BTLact was repeated.RESULTS： Based on the BTLact results, SIBO was present in about 56% of IBS patients, and it was responsible for some IBS-related symptoms, such as abdominal bloating and discomfort, and diarrhoea. 1-wk treatment with Rifaximin turned the BTLact to negative in about 50% of patients and significantly reduced the symptoms, especially in those patients with an alternated constipation/diarrhoea-variant IBS. CONCLUSION： SIBO should be always suspected in patients with IBS, and a differential diagnosis is done by means of a ＂breath test＂. Rifaximin may represent a valid approach to the treatment of SIBO.

关键词： Rifaximin Small intestinal bacterialovergrowth Irritable bowel syndrome Locally nonabsorbable antibiotics

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PHASE DIFFERENCE BETWEEN LOW-FREQUENCY OSCILLATIONS OF CEREBRAL DEOXY-AND OXY-HEMOGLOBIN CONCENTRATIONS DURING A MENTAL TASK

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Journal of Innovative Optical Health Sciences 2011年第2期4卷 151-158页

作者： ANGELO SASSAROLI FENG ZHENG MICHELE PIERRO PETER R.BERGETHON sergio FANTINI Department of Biomedical Engineering Tufts University 4 Colby StreetMedfordMA 02155USA

Hemodynamic low-frequency(~0.1 Hz)spontaneous oscillations as detected in the brain by nearinfrared spectroscopy have potential applications in the study of brain activation,cerebral autoregulation,and functional *** this work,we have investigated the phase lag between oscillations of cerebral deoxy-and oxy-hemoglobin concentrations in the frequency range 0.05-0.10 Hz in a human subject during a mental workload *** have obtained a measure of such phase lag using two different methods:(1)phase synchronization analysis as used in the theory of chaotic oscillators and(2)a novel cross-correlation phasor *** two methods yielded comparable initial results of a larger phase lag between low-frequency oscillations of deoxy-and oxyhemoglobin concentrations during mental workload with respect to a control,rest condition.

关键词： Phase lag oxyhemoglobin deoxyhemoglobin phase synchronization cross-correlation phasor LFO

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Theoretical analysis on ground vibration attenuation using sub-track asphalt layer in high-speed rails

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Journal of Modern Transportation 2015年第3期23卷 214-219页

作者： Mingjing Fang sergio Fernández Cerdas Department of Road & Bridge Engineering School of TransportationWuhan University of Technology(WUT) Faculty of Costa Rica Institute of Technology Costa Rican Building Research Center Costa Rica Institute of Technology100 metros este10 metros sury 500m este del Estadio Fello MezaCartagoCosta Rica

Using a finite element method （FEM） program, a Portland cement concrete slab trackbed （So）, and a sub- track asphalt roadbed （RAC-S） were modeled under high- speed train loads to analyze their responses to ground vibration attenuation, by considering 10, 15, 20, 25, and 30 thick sub-track asphalt layer replaced on the top of the upper subgrade. FEM results show that the vibration amplitude of RAC-S is at least three times lower than the vibration for So. The maximum vibration amplitude of RAC-S is linearly increased with train speed. The vertical acceleration is found to be reduced by more than 10 % when the asphalt layer thickness is increased from 10 to 20 cm. However, the reduction in vertical acceleration is only about 1% when the thickness of the asphalt layer changes from 20 to 30 cm. The vibration level is slightly lower if the asphalt layer has higher resilient modulus in the seasons of autumn or winter. This theoretical analysis indicates that a railway substructure that consists of a 10-20 cm thick high modulus asphalt layer located at the top of trackbed shows a good performance in ground vibration control for high-speed rails.

关键词： High-speed railway· Substructure · TrackbedAsphalt mix· Ground vibration attenuation ·Mechanismanalysis

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A rheological method for selecting nano-kaolin powder as filler in SBR rubber

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Particuology 2010年第3期8卷 245-250页

作者： Alberto Lagazzo sergio Lenzi Rodolfo Botter Paolo Cirillo Fabrizio Demicheli Dario T. Beruto Department of Civil Environmental and Architectural Engineering (DICAT) University of Genoa P.le Kennedy (Fiera del Mare) Pad. D 16129 Genoa Italy Artigo S.p.A. loc. Carpeneto 17014 Cairo Montenotte (SV) Italy

This paper shows that the stiffness ofstyrene-butadiene solid rubber with added kaolin powder is related to the yield stress of kaolin dispersion in liquid polybutadiene rubber up to the percolation threshold. For five kinds of kaolin powder, the value of τ° spans the range of 100-430 Pa, while the corresponding compressive elastic constant of SBR varies from 12 to 21 MPa. A relationship between τ° and △E^i^＊/ER^＊ is proposed. Critical examination of these data infers that kaolin powder dispersed in solid rubber matrix acts as an additive which decreases the random movement of the polybutadiene chains. Consequently, dispersions of nano-particles in liquid and in solid SBR are considered to be related, thus leading to a theological method for selecting nano-particles as fillers in solid SBR.

关键词： Yield stress Kaolin Filler dispersion Stiffness Styrene-butadiene rubber (SBR)Liquid polybutadieneRheology

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Optimization for performance-based design under seismic demands, including social costs

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Earthquake Engineering and Engineering Vibration 2015年第2期14卷 315-328页

作者： Oscar Moller Ricardo O.Foschi Juan P.Ascheri Marcelo Rubinstein sergio Grossman Instituto de Mecanica Aplicada y Estructuras (IMAE) Facultad Cs.Ex. Ingenieríay Agrimensura Universidad Nacional de Rosario Riobambay Berutti 2000 Rosario Argentina Civil Engineering Department University of British Columbia 6250 Applied Sciences Lane Vancouver B.C. Canada V6T1Z4

Performance-based design in earthquake engineering is a structural optimization problem that has, as the objective, the determination of design parameters for the minimization of total costs, while at the same time satisfying minimum reliability levels for the specifi ed performance criteria. Total costs include those for construction and structural damage repairs, those associated with non-structural components and the social costs of economic losses, injuries and fatalities. This paper presents a general framework to approach this problem, using a numerical optimization strategy and incorporating the use of neural networks for the evaluation of dynamic responses and the reliability levels achieved for a given set of design parameters. The strategy is applied to an example of a three-story offi ce building. The results show the importance of considering the social costs, and the optimum failure probabilities when minimum reliability constraints are not taken into account.

关键词： earthquake engineering performance-based design optimization reliabiliy social costs

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Seasonal variations of rotifers from a high altitude urban shallow water body, La Cantera Oriente (Mexico City, Mexico)

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Chinese Journal of Oceanology and Limnology 2017年第6期35卷 1387-1397页

作者： sergio González GUTIERREZ S.S.S. SARMA S. NANDINI Postgraduate Programme in Marine Sciences and Limnology National Autonomous University of Mexico Circuito Exterior sin Ciudad Universitaria Mexico City 04510 Mexico Laboratory of Aquatic Zoology Division of Research & Postgraduate Studies National Autonomous University of Mexico Campus Iztacala Av. de los Barrios No.1 AP 314 Los Reyes Tlalnepantla State of Mexico 54090 Mexico

La Cantera Oriente is a shallow freshwater volcanic water body located at an altitude of 2 270 m above sea level in the Ecological Reserve of San Angel Pedregal of Mexico City （Mexico）. In order to ensure the conservation of its biological heritage including zooplankton, the present work was undertaken to quantify the seasonal changes in the diversity and density of rotifers and the selected physico- chemical variables during 2013-2014. Qualitative analysis of the zooplankton samples yielded 68 rotifer species which represented 24 genera in 15 families. Brachionus calyciflorus Pallas, 1766, B. quadridentatus Hermann, 1783, Polyarthra vulgaris Carlin, 1943, Lecane closterocerca （Schmarda, 1859） and Keratella cochlearis （Gosse, 1851） were the most common species. Preston plots of species frequency-density revealed that as many as 30% of the rotifer taxa were dominant throughout the year. The species with high population densities were Brachionus quadridentatus, Lecane closterocerca, Keratella cochlearis, and Lepadellapatella; their peak densities were 2 000, 1 000, 180 and 90 ind./L, all occurring in summer. Canonical correspondence analysis showed that Platyias quadricornis was related to the concentration of phosphates available in the environment and the conductivity, while B. quadridentatus was positively correlated with chlorophyll-a. The trophic status of the lake was eutrophic based on Chl-a content but oligotrophic with relation to the Braehionus： Trichocerca ratio.

关键词： high altitude zooplankton seasonal density dynamics limnology rotifera

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