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Influence of climatic conditions,topography and soil attributes on the spatial distribution of site productivity index of the species rich forests of Jalisco,mexico

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Journal of Forestry Research 2014年第1期25卷 87-95页

作者： Adel mohamed robin m.reich Raj Khosla C.Aguirre-Bravo martin mendoza Briseo Department of Ecology and Rangeland Stewardship Desert Research Center Department of Forest and Rangeland Stewardship Colorado State University Department of Soil and Crop Sciences Colorado State University USDA Forest Service Colegio de Postgraduados

This paper presents an approach based on field data to model the spatial distribution of the site productivity index （SPI） of the diverse forest types in Jalisco, mexico and the response in SPI to site and cli-matic conditions. A linear regression model was constructed to test the hypothesis that site and climate variables can be used to predict the SPI of the major forest types in Jalisco. SPI varied significantly with topog-raphy （elevation, aspect and slope）, soil attributes （pH, sand and silt）, climate （temperature and precipitation zones） and forest type. The most important variable in the model was forest type, which accounted for 35% of the variability in SPI. Temperature and precipitation accounted for 8 to 9% of the variability in SPI while the soil attributes accounted for less than 4% of the variability observed in SPI. No significant differences were detected between the observed and predicted SPI for the individual forest types. The linear regression model was used to develop maps of the spatial variability in predicted SPI for the individual forest types in the state. The spatial site productivity models developed in this study provides a basis for understanding the complex relationship that exists between forest productivity and site and climatic conditions in the state. Findings of this study will assist resource managers in making cost-effective decisions about the management of individual forest types in the state of Jalisco, mexico.

关键词： Best management practices climate change spatial predic-tions tropical dry forests weighted least squares

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Empirical evaluation of confidence and prediction intervals for spatial models of forest structure in Jalisco,mexico

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Journal of Forestry Research 2011年第2期22卷 159-166页

作者： robin m.reich C.Aguirre-Bravo Vanessa A.Bravo martin mendoza Briseo Department of Forest and Rangeland Stewardship Colorado State UniversityFort CollinsCO 80523-1472 USA USDA Forest Service ArlingtonVA 22209-2131 USA Clegio de Postgraduados Campus MontecillosTexcocoMexico

In recent years there has been an increasing interest in developing spatial statistical models for data sets that are seemingly spatially *** lack of spatial structure makes it difficult,if not impossible to use optimal predictors such as ordinary kriging for modeling the spatial variability in the *** many instances,the data still contain a wealth of information that could be used to gain flexibility and precision in *** this paper we propose using a combination of regression analysis to describe the large-scale spatial variability in a set of survey data and a tree-based stratification design to enhance the estimation process of the small-scale spatial *** this approach,sample units（i.e.,pixel of a satellite image） are classified with respect to predictions of error attributes into homogeneous classes,and the classes are then used as strata in the stratified *** variables used as a basis of stratification included terrain data and satellite imagery.A decision rule was used to identify a tree size that minimized the error in estimating the variance of the mean response and prediction uncertainties at new spatial *** approach was applied to a set of n=937 forested plots from a state-wide inventory conducted in 2006 in the mexican State of *** final models accounted for 62% to 82% of the variability observed in canopy closure（%）,basal area（m2·ha-1）,cubic volumes（m3·ha-1） and biomass（t·ha-1） on the sample *** spatial models provided unbiased estimates and when averaged over all sample units in the population,estimates of forest structure were very close to those obtained using classical estimates based on the sampling strategy used in the state-wide *** spatial models also provided unbiased estimates of model variances leading to confidence and prediction coverage rates close to the 0.95 nominal rate.

关键词： tree-based stratified design generalized least squares standardized mean squared error Landsat-7 ETm+

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Small-area estimation of forest stand structure in Jalisco, mexico

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Journal of Forestry Research 2009年第4期20卷 285-292,I0004页

作者： robin m. reich Celedonio Aguirre-Bravo Department of Forest Rangeland and Watershed Stewardship Colorado State University Fort Collins Rocky mountain Research Station USDA Forest Service Fort Collins

Natural resource statistics are often unavailable for small ecological or economic regions and policymakers have to rely on state-level datasets to evaluate the status of their resources （i.e., forests, rangelands, grasslands, agriculture, etc.） at the regional or local level. These resources can be evaluated using small-area estimation techniques. However, it is unknown which small area technique produces the most valid and precise results. The reliability and accuracy of two methods, synthetic and regression estimators, used in smallarea analyses, were examined in this study. The two small-area analysis methods were applied to data from Jalisco＇s state-wide natural resource inventory to examine how well each technique predicted selected characteristics of forest stand structure. The regression method produced the most valid and precise estimates of forest stand characteristics at multiple geographical scales. Therefore, state and local resource managers should utilize the regression method unless appropriate auxiliary information is not available.

关键词： forest structure regression estimator synthetic estimator spatial model stratified random sampling satellite imagery inventory and monitoring

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Host-environment mismatches associated with subalpine fir decline in Colorado

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Journal of Forestry Research 2016年第5期27卷 1177-1189页

作者： robin m. reich John E. Lundquist Kristina Hughes Colorado State University Fort Collins CO USA U.S. Forest Service Anchorage Anchorage AK 99501 USA

Subalpine fir decline （SFD） has killed more trees in Colorado＇s high elevation forests than any other insect or disease problem. The widespread nature of this disorder suggests that the cause involves climatic factors. We examined the influence of varying combinations of average annual temperature and precipitation on the incidence and distribution of SFD. Climatic transition matrices generated in this study indicate that most healthy trees are found in climatic zones with moderate to low temperatures and high precipitation; whereas, SFD occurs mostly in zones of moderate temperatures and moderate precipitation. The contrasting distributions define an environmental mismatch. Forests matched with favorable climatic conditions thrive; those that are mismatched can become vulnerable to decline disease.

关键词： Abiotic disorder Climate stress High elevation forests Forest disease - Subalpine fir

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New Breakdown Electric Field Calculation for SF6 High Voltage Circuit Breaker Applications

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Plasma Science and Technology 2007年第6期9卷 690-694页

作者： Ph.robin-JOUAN m.YOUSFI AREVA T & D High Voltage Switchgear Research Centre 130 rue L.BLUM 69611 VilleurbanneFrance University of Toulouse LAPLACE-UMR 5213 CNRSUPS118 Route de Narbonne31062 Toulouse Cedex 9France

The critical electric fields of hot SF6 are calculated including both electron and ion kinetics in wide ranges of temperature and pressure, namely from 300 K up to 4000 K and 2 atmospheres up to 32 atmospheres respectively. Based on solving a multi-term electron Boltz- mann equation the calculations use improved electron-gas collision cross sections for twelve SF6 dissociation products with a particular emphasis on the electron-vibrating molecule interactions. The ion kinetics is also considered and its role on the critical field becomes non negligible as the temperature is above 2000 K. These critical fields are then used in hydrodynamics simulations which correctly predict the circuit breaker behaviours observed in the case of breaking tests.

关键词： breakdown electric field hot dissociated SF6 high voltage gas-circuit-breaker

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Distance management of inflammatory bowel disease:Systematic review and meta-analysis

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World Journal of Gastroenterology 2014年第3期20卷 829-842页

作者： Vivian W Huang Krista m.reich Richard N Fedorak Division of Gastroenterology University of Alberta

AIm: To review the effectiveness of distance management methods in the management of adult inflammatory bowel disease (IBD) patients.

关键词： Telemanagement Telehealth Inflammatory bowel disease Distance management Self-management

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Vitamin D improves inflammatory bowel disease outcomes:Basic science and clinical review

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World Journal of Gastroenterology 2014年第17期20卷 4934-4947页

作者： Krista m.reich Richard N Fedorak Karen madsen Karen I Kroeker Division of Gastroenterology University of AlbertaEdmontonAlberta T6G 2X8Canada

Vitamin D deficiency is commonly diagnosed among patients with inflammatory bowel disease (IBD). Patients with IBD are at risk of low bone density and increased fractures due to low vitamin D levels, long standing disease, and frequent steroid exposures; as a result, it is well established that vitamin D supplementation in this population is important. There is increasing support for the role of vitamin D in strengthening the innate immune system by acting as an immunomodulator and reducing inflammation in experimental and human IBD. The active form of vitamin D, 1,25(OH)D3, acts on T cells to promote T helper (Th)2/regulatory T responses over Th1/Th17 responses; suppresses dendritic cell inflammatory activity; induces antibacterial activity; and regulates cytokine production in favor of an anti-inflammatory response. murine and human IBD studies support a therapeutic role of vitamin D in IBD. Risk factors for vitamin D deficiency in this population include decreased sunlight exposure, disease duration, smoking, and genetics. Vitamin D normalization is associated with reduced risk of relapse, reduced risk of IBD-related surgeries, and improvement in quality of life. Vitamin D is an inexpensive supplement which has been shown to improve IBD outcomes. However, further research is required to determine optimal serum vitamin D levels which will achieve beneficial immune effects, and stronger evidence is needed to support the role of vitamin D in inducing disease response and remission, as well as maintaining this improvement in patients’ disease states.

关键词： Vitamin D Inflammatory bowel disease Immune response Inflammation Cytokines Supplementation

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Analyzing voting power in decentralized governance:Who controls DAOs?

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Blockchain(Research and Applications) 2024年第3期5卷 123-129页

作者： robin Fritsch marino müller Roger Wattenhofer ETH Zurich 8092ZurichSwitzerland

We empirically study the state of three prominent DAO governance systems on the Ethereum blockchain:Compound,Uniswap and Ethereum name service(ENS).In particular,we examine how the voting power is distributed in these *** a comprehensive dataset of all governance token holders,delegates,propos-als,and votes,we analyze who holds the voting power and how this power is being used to influence governance *** we reveal that the majority of voting power is concentrated in the hands of a small number of addresses,we rarely observe these powerful entities overturning a vote by choosing a different outcome than that of the overall community and less influential voters.

关键词： Decentralized autonomous organization DAO governance Liquid democracy Blockchain

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A Perfect Storm That Threatens American Democracy

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中国翻译 2011年第6期32卷 71-72页

作者： Robert reich 不详

It＇s a perfect storm. And I＇m not talking about the impending dangers facing Democrats. I＇m talking about the dangers facing our democracy.

关键词：英语学习学习方法英语翻译阅读材料

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在Triton X-100/甲苯闪烁液中不同量盐水溶液样品的3H计数效率及其时间稳定性

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核农学通报 1980年第4期 61-65+52页

作者： V.Zarybnicky m.reich 郝心仁

引言水溶液样品在 Triton X-100/甲苯闪烁液中的液体闪烁计数,已成为一种广泛应用的技术。就非水样品而言,它在 Triton X-100甲苯闪烁液中的效率,要低于在 Triton 的甲苯闪烁液中的效率;但对水溶液样品而言,它的效率比在以醇类或二氧六... 详细信息

引言水溶液样品在 Triton X-100/甲苯闪烁液中的液体闪烁计数,已成为一种广泛应用的技术。就非水样品而言,它在 Triton X-100甲苯闪烁液中的效率,要低于在 Triton 的甲苯闪烁液中的效率;但对水溶液样品而言,它的效率比在以醇类或二氧六环(如 Bray 闪烁液)为溶剂的闪烁液中好得多,重复性也较好。

关键词：相对效率胶态甲苯闪烁液分子团 Triton X-100

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