检索结果-南通市图书馆

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

引用

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 timber.Teak 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 pattern.Tree 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 Colombia.Environmental noise and height measurement errors were explicitly considered as the main uncertainty sources of mean top height growth.The 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 parameters.This model outperformed its counterpart that had the growth rate specified as a local parameter and asymptote and shape as global parameters.The selected model also outperformed alternative approaches such as the mixed-effects model,generalized algebraic difference approach,and the dummy variable method.Estimated trajectories for the mean top height of teak in Colombia are biologically sound based on the measured height series and previous studies in Latin America.Results suggest that most of the uncertainty associated with the mean top height growth of teak plantations in Colombia was largely explained by environmental noise.The 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

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Quantitative morphometric analysis of the Jama River profile in a tectonically active margin (Northwestern Ecuador)

引用

Journal of Mountain Science 2018年第5期15卷 966-975页

作者： Pedro S.B. REYES mauricio E. VALAREZO Jenry CORDOVA Francois A. MICHAUD Camilo zapata Department of Geology Escuela Politécnica Nacional Ladrón de Gueuara E11-253 PO.Box 17-01-2759 Quito Ecuador C-eostrat S.A. Jorge Drom N39-188y Gaspar de Villaroel Quito Ecuador Department of Civil and Environmental Engineering Escuela Politécnica National Ladrón de Guevara E11-253 PO.Box17-ol-2759 Quito Ecuador Sorbonne Université Université Cote d'Azur IRD CNRS Observatoire de la Cdte d'Azur C-eoazur 250 rue A. EinsteinSophia Antipolis 06560 Valbonne France

The longitudinal profile of a river channel can be described in function of mathematical expressions. The logarithmic fit is the most used method to describe the relative equilibrium of a channel elevation profile. Rivers showing zones of high channel gradient and convex-upward profiles can be evaluated in function of the offset distance with respect to the logarithmic curve. The Jama River profile has been constructed using differential GPS data for the downstream reach and 4-m-grid DEM data base for the remaining headward profile. The resulting longitudinal profile shows a prominent knickpoint of about 80 m in elevation characterized by sharp local convexity. The offset distance in vertical direction from the logarithmic plot is interpreted as the successive accumulation of multiple uplift episodes associated with the Jama Fault System activity. The horizontal offset is suggested to represent the remaining retreated distance for the upstream propagation of the Jama knickpoint. The highly resistant Cretaceous rocks outcropping along the Jama knickpoint reach acts as an inflection point between two subprofiles that show well-fitted logarithmic curves, thereby representing a temporary partitioned equilibrium along the Jama River profile.

关键词： Morphometry Jama River Stream profile Active tectonics

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Anterior and Posterior Approach Results for Treatment of Cervical Myelopathy in the Elderly: A 10-Year Experience in a Mexican Institution

引用

Open Journal of Orthopedics 2021年第7期11卷 207-219页

作者： mauricio Daniel Sánchez-Calderón María Elena Córdoba-Mosqueda José Ramón Aguilar-Calderón Carlos René Domínguez-Herz Diego Ochoa-Cacique Daniel Alejandro Vega-Moreno Victor Andrés Reyes-Rodriguez Ulises García-González Abraham Ibarra-de la Torre Rodrigo Efraín Hernández-Reséndiz Department of Neurosurgery Hospital Central Sur de Alta Especialidad de Alta Especialidad de PEMEX Periferico sur 4091 Fuentes del Pedregal Tlalpan México City México Department of Neurosurgery Hospital Regional de Alta Especialidad “Centenario de la Revolución Mexicana” ISSSTE Cuernavaca Palo Escrito Emiliano Zapata Department of Neurosurgery Hospital Central Norte PEMEX Mexico City México Department of Neurosurgery Hospital &Aacute ngeles Clí nica Londres Mexico City Mexico

Introduction: Degeneration of the cervical spine (CDSD) prevalence is nearly 90% by the 7th decade. This is the first research that compares the outcomes between the Anterior Approach (AA) and Posterior Approach (PA) to cervical myelopathy (CM) in the elderly. Materials and Methods: A retrospective observational study of electronic health records at the Hospital Central Sur de Alta Especialidad (HCSAE), PEMEX from January 2010 to May 2020 with patients older than 60 years submitted to cervical surgery. For the analysis we elaborated two groups according to the surgical approach: AA vs PA;we analyzed the trans-operative behavior, the immediate outcome, and after 3 months, 6 months, and 1 year. Results: As a total of 145 patients, the prevalence of CM in elderly was the 63.8% with a median age of 69 (64 - 75) years. We found statistical differences in strength outcome only in the P3m (p = 0.011), for sensitivity we found major prevalence of affection in the PA group. We didn’t report a significant difference in the Neck Disability Index (NDI) at all measures, but the PA presented a major incapacity. The Nurick scale results were significant in all stages (p . Discussion: Patients show significant improvements in outcome measures with either anterior or posterior surgery. Both approaches are highly efficacious in preventing neurologic deterioration and in most cases improve neur

关键词： Cervical Spine Surgical Approach Elderly Cervical Myelopathy Cervical Degenerative Spine Disease

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：