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Why ecosystem characteristics predicted from remotely sensed data are unbiased and biased at the same time-and how this affects applications

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Forest ecosystems 2024年第1期11卷 24-31页

作者： Goran Ståhl Terje Gobakken Svetlana Saarela Henrik J.Persson Magnus ekstrom Sean P.Healey Zhiqiang Yang Johan Holmgren eva Lindberg Kenneth Nystrom emanuele Papucci Patrik Ulvdal Hans OleØrka erik Næsset Zhengyang Hou Håkan Olsson ronald e.mcroberts Department of Forest Resource Management Swedish University of Agricultural Sciences90183UmeåSweden Faculty of environmental Sciences and Natural Resource Management Norwegian University of Life SciencesÅsNorway USDA Forest Service Rocky Mountain Research StationOgdenUTUSA The Key Laboratory for Silviculture and Conservation of Ministry of education Beijing Forestry UniversityBeijing100083China Department of Forest Resources University of MinnesotaSt.PaulMNUSA

Remotely sensed data are frequently used for predicting and mapping ecosystem characteristics,and spatially explicit wall-to-wall information is sometimes proposed as the best possible source of information for ***,wall-to-wall information typically relies on model-based prediction,and several features of model-based prediction should be understood before extensively relying on this type of *** such feature is that model-based predictors can be considered both unbiased and biased at the same time,which has important implications in several areas of *** this discussion paper,we first describe the conventional model-unbiasedness paradigm that underpins most prediction techniques using remotely sensed(or other)auxiliary *** this point of view,model-based predictors are typically ***,we show that for specific domains,identified based on their true values,the same model-based predictors can be considered biased,and sometimes severely *** suggest distinguishing between conventional model-bias,defined in the statistical literature as the difference between the expected value of a predictor and the expected value of the quantity being predicted,and design-bias of model-based estimators,defined as the difference between the expected value of a model-based estimator and the true value of the quantity being *** show that model-based estimators(or predictors)are typically design-biased,and that there is a trend in the design-bias from overestimating small true values to underestimating large true ***,we give examples of applications where this is important to acknowledge and to potentially make adjustments to correct for the design-bias *** argue that relying entirely on conventional model-unbiasedness may lead to mistakes in several areas of application that use predictions from remotely sensed data.

关键词： Bias Model-based inference Design-based inference

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Cross-classes domain inference with network sampling for natural resource inventory

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Forest ecosystems 2022年第3期9卷 311-322页

作者： Zhengyang Hou ronald e.mcroberts Chunyu Zhang Göran Ståhl Xiuhai Zhao Xuejun Wang Bo Li Qing Xu The Key Laboratory for Silviculture and Conservation of Ministry of education Beijing Forestry UniversityBeijingChina Department of Forest Resources University of MinnesotaSaint PaulMNUnited States Department of Forest Resource Management Swedish University of Agricultural SciencesUmeåSweden Office of the National Forestry and Grassland Administrations Forest Resources Supervision Commissioner in Beijing BeijingChina Department of Statistics University of Illinois at Urbana-ChampaignChampaignILUnited States Key Laboratory on the Science and Technology of Bamboo and Rattan International Centre for Bamboo and RattanBeijingChina

There are two distinct types of domains,design-and cross-classes domains,with the former extensively studied under the topic of small-area *** natural resource inventory,however,most classes listed in the condition tables of national inventory programs are characterized as cross-classes domains,such as vegetation type,productivity class,and age *** date,challenges remain active for inventorying cross-classes domains because these domains are usually of unknown sampling frame and spatial distribution with the result that inference relies on population-level as opposed to domain-level *** challenges are noteworthy:(1)efficient sampling strategies are difficult to develop because of little priori information about the target domain;(2)domain inference relies on a sample designed for the population,so within-domain sample sizes could be too small to support a precise estimation;and(3)increasing sample size for the population does not ensure an increase to the domain,so actual sample size for a target domain remains highly uncertain,particularly for small *** this paper,we introduce a design-based generalized systematic adaptive cluster sampling(GSACS)for inventorying cross-classes ***-unbiased Hansen-Hurwitz and Horvitz-Thompson estimators are derived for domain totals and compared within GSACS and with systematic sampling(SYS).Comprehensive Monte Carlo simulations show that(1)GSACS Hansen-Hurwitz and Horvitz-Thompson estimators are unbiased and equally efficient,whereas thelatter outperforms the former for supporting a sample of size one;(2)SYS is a special case of GSACS while the latter outperforms the former in terms of increased efficiency and reduced intensity;(3)GSACS Horvitz-Thompson variance estimator is design-unbiased for a single SYS sample;and(4)rules-ofthumb summarized with respect to sampling design and spatial effect improve *** inventorying a mini domain is analogous to inventorying a rare vari

关键词： Cross-classes domain estimation Design-based inference Network sampling Generalized systematic adaptive cluster sampling Forest inventory

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evolution in the treatment of metastatic colorectal carcinoma of the liver

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World Journal of Gastroenterology 2006年第20期12卷 3253-3258页

作者： Charlotte e Ariyan ronald R Salem Department of Surgery Section of Surgical Oncology Yale University School of MedicineTompkins 202333 Cedar StreetNew HavenCT 06520United States

Metastatic colorectal cancer to the liver is associated with a uniform poor prognosis without treatment. Advances in therapy over the past decades have now allowed surgical resections of the liver to occur with a low morbidity and mortality. Improvements in chemotherapy regimes have paralleled technical improvements and now allow a new group of patients to become eligible for surgical resection. This chapter will review the recent advances in surgical and chemotherapeutic regimes in metastatic colorectal cancer to the liver.

关键词： ethical tensions Metastatic Colorectal Carcinoma Liver

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Use of models in large-area forest surveys： comparing model-assisted, model-based and hybrid estimation

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Forest ecosystems 2016年第2期3卷 153-163页

作者： Goran Stahl Svetlana Saarela Sebastian Schnell Soren Holm Johannes Breidenbach Sean P. Healey Paul L. Patterson Steen Magnussen erik Naesset ronald e. mcroberts Timothy G. Gregoire Department of Forest Resource Management Swedish University of Agricultural Sciences UmeA Sweden. Norwegian Institute for Bioeconomy Research As Norway. USDA Forest Service Washington D.C. USA. Canadian Forest Service Pacific Forestry Centre British Columbia Canada Norwegian University of Life Sciences As Norway. School of Forestry and Fnvirnnmental Studies. Yale Universitv New Haven CT USA.

This paper focuses on the use of models for increasing the precision of estimators in large-area forest surveys. It is motivated by the increasing availability of remotely sensed data, which facilitates the development of models predicting the variables of interest in forest surveys. We present, review and compare three different estimation frameworks where models play a core role： model-assisted, model-based, and hybrid estimation. The first two are well known, whereas the third has only recently been introduced in forest surveys. Hybrid inference mixes design- based and model-based inference, since it relies on a probability sample of auxiliary data and a model predicting the target variable from the auxiliary *** review studies on large-area forest surveys based on model-assisted, model- based, and hybrid estimation, and discuss advantages and disadvantages of the approaches. We conclude that no general recommendations can be made about whether model-assisted, model-based, or hybrid estimation should be preferred. The choice depends on the objective of the survey and the possibilities to acquire appropriate field and remotely sensed data. We also conclude that modelling approaches can only be successfully applied for estimating target variables such as growing stock volume or biomass, which are adequately related to commonly available remotely sensed data, and thus purely field based surveys remain important for several important forest parameters.

关键词： Design-based inference Model-assisted estimation Model-based inference Hybrid inference Nationalforest inventory Remote sensing Sampling

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Comparison of estimators of variance for forest inventories with systematic sampling-results from artificial populations

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Forest ecosystems 2020年第2期7卷 215-233页

作者： Steen Magnussen ronald emcroberts Johannes Breidenbach Thomas Nord-Larsen Göran Ståhl Lutz Fehrmann Sebastian Schnell 506 West Burnside Road VictoriaBC V8Z 1M5Canada Raspberry Ridge Analytics 15111 Elmcrest Avenue NorthHugoMN 55038USA Norwegian Institute of Bioeconomy Research Høgskolevegen 81431ÅsNorway Department of Geosciences and Natural Resource Management University of CopenhagenRolighedsvej 23DK-1958 Frederiksberg CDenmark Department of Forest Resource Management Swedish University of Agricultural SciencesUmeåSweden Forest Inventory and Remote Sensing Faculty of Forest SciencesUniversity of GöttingenBüsgenweg 5D37077GöttingenGermany Alfred-Möller-Straße 1 Haus 41-4216225 EberswaldeGermany.

Background:Large area forest inventories often use regular grids(with a single random start)of sample locations to ensure a uniform sampling intensity across the space of the surveyed populations.A design-unbiased estimator of variance does not exist for this ***,a quasi-default estimator applicable to simple random sampling(SRS)is used,even if it carries with it the likely risk of overestimating the variance by a practically important *** better exploit the precision of systematic sampling we assess the performance of five estimators of variance,including the quasi *** this study,simulated systematic sampling was applied to artificial populations with contrasting covariance structures and with or without linear *** compared the results obtained with the SRS,Matern’s,successive difference replication,Ripley’s,and D’Orazio’s variance ***:The variances obtained with the four alternatives to the SRS estimator of variance were strongly correlated,and in all study settings consistently closer to the target design variance than the estimator for *** latter always produced the greatest *** populations with a near zero spatial autocorrelation,all estimators,performed equally,and delivered estimates close to the actual design ***:Without a linear trend,the SDR and DOR estimators were best with variance estimates more narrowly distributed around the benchmark;yet in terms of the least average absolute deviation,Matern’s estimator held a narrow *** a strong or moderate linear trend,Matern’s estimator is *** large populations,and a low sampling intensity,the performance of the investigated estimators becomes more similar.

关键词： Spatial autocorrelation Linear trend Model based Design biased Matern variance Successive difference replication variance Geary contiguity coefficient Random site effects

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exact and Approximate Values of the Period for a “Truly Nonlinear” Oscillator: x + x + x^(1/3)= 0

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Advances in Applied Mathematics and Mechanics 2009年第3期1卷 383-390页

作者： ronald e.Mickens Dorian Wilkerson Department of Physics Clark Atlanta UniversityAtlantaGA 30314USA Department of Mathematics Clark Atlanta UniversityAtlantaGA 30314USA

We investigate the mathematical properties of a“truly nonlinear”oscillator differential *** particular,using phase-space methods,it is shown that all solutions are periodic and the fixed-point is a nonlinear *** calculate both exact and approximate analytical expressions for the period,where the exact solution is given in terms of elliptic functions and the method of harmonic balance is used to calculate the approximate formula.

关键词： Nonlinear oscillations periodic solutions qualitative methods special functions

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Nonlinear evolution of Non-axisymmetric Dynamical Instability in a Slender Accretion Torus

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Science China Mathematics 1994年第1期37卷 99-111页

作者：王德焴 ronald e. Taam 吴丁 Purple Mountain Observatory Academia Sinica Nanjing 210008 PRC Department of Physics and Astronomy Northwestern University evanston Illinois 52021 USA

The nonlinear evolution of non-axisymmetric dynamical instability has been interpreted here wuhin the framework of soliton *** dispersion relation of a two-dimensional slender accretion torus in the long wavelength incompressible limit is similar to that of the linearized KdV *** argue that the ’planet-like’ solutions of nonlinear dynamical instability in the numerical simulations should he the soliton solutions of KdV *** also find that the vorticity of accretion disk is a non-conservation quantity due to the variation of density and entropy in the nonlinear evolution of dynamical instability It is the cause of the redistribution of angular momentum during the instability.

关键词： accretion disk theory nonlinear dynamical instability KdVequation

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Stereotactic radiosurgery for haemorrhagic cerebral cavernous malformation:a multi-institutional,retrospective study

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Stroke & Vascular Neurology 2024年第3期9卷 221-229,I0130,I0131页

作者： Chloe Dumot Georgios Mantziaris Sam Dayawansa Zhiyuan Xu Stylianos Pikis Selcuk Peker Yavuz Samanci Gokce D Ardor Ahmed M Nabeel Wael A Reda Sameh R Tawadros Khaled Abdelkarim Amr M N el-Shehaby Reem M emad eldin Ahmed H elazzazi Nuria Martínez Moreno Roberto MartínezÁlvarez Roman Liscak Jaromir May David Mathieu Jean-Nicolas Tourigny Manjul Tripathi Akshay Rajput Narendra Kumar Rupinder Kaur Piero Picozzi Andrea Franzini Herwin Speckter Wenceslao Hernandez Anderson Brito ronald e Warnick Juan Alzate Douglas Kondziolka Greg N Bowden Samir Patel Jason Sheehan Department of Neurological Surgery Hospices Civils de LyonLyonFrance Department of Neurological Surgery University of VirginiaCharlottesvilleVirginiaUSA Department of Neurosurgery Koc University School of MedicineIstanbulTurkey Gamma-knife Center Nasser institute HospitalCairoEgypt Neurosurgery Department Benha UniversityBenhaEgypt Departments of Neurosurgery Ain Shams UniversityCairoEgypt Department of Clinical Oncology Ain Shams UniversityCairoEgypt Department of Radiation Oncology National Cancer InstituteCairo UniversityGizaEgypt Faculty of Medicine Extended Modular ProgramAin Shams UniversityCairoEgypt Department of Radiosurgery Rúber Internacional HospitalMadridSpain Department of Stereotactic and Radiation Neurosurgery Na Homolce HospitalPragueCzech Republic Neurosurgery Centre de recherche du CHUSUniversitéde SherbrookeSherbrookeQuebecCanada Neurosurgery PGIMERChandigarhChandigarhIndia Radiation Therapy PGIMERChandigarhChandigarhIndia Neurosurgery IRCCS Istituto Clinico HumanitasRozzanoMilanItaly Dominican Gamma Knife Center and Radiology Department CEDIMATSanto DomingoDominican Republic Gamma Knife Center Mayfield ClinicThe Jewish Hospital-Mercy HealthCincinnatiOhioUSA Neurosurgery NYU Langone HealthNew YorkNew YorkUSA Neurosurgery University of AlbertaEdmontonAlbertaCanada Division of Radiation Oncology Department of OncologyUniversity of AlbertaEdmontonAlbertaCanada

Background Cerebral cavernous malformations(CCMs)frequently manifest with *** radiosurgery(SRS)has been employed for CCM not suitable for *** effect on reducing haemorrhage risk is still *** aim of this study was to expand on the safety and efficacy of SRS for haemorrhagic *** This retrospective multicentric study included CCM with at least one haemorrhage treated with single-session *** annual haemorrhagic rate(AHR)was calculated before and after *** event analysis and Cox regression were used to evaluate factors associated with *** radiation effects(ARes)and occurrence of new neurological deficits were *** The study included 381 patients (median age:37.5 years(Q1–Q3:25.8–51.9))with 414 *** AHR from diagnosis to SRS excluding the first haemorrhage was 11.08 per 100 CCM-years and was reduced to 2.7 per 100 CCM-years after *** recurrent event analysis,SRS,HR 0.27(95%CI 0.17 to 0.44),ped with a decreased risk of haemorrhage,and the presence of developmental venous anomaly(DVA)with an increased risk,HR 1.60(95%CI 1.07 to 2.40),p=*** cumulative risk of first haemorrhage after SRS was 9.4%(95%CI 6%to 12.6%)at 5 years and 15.6%(95%CI%9 to 21.8%)at 10 *** doses>13 Gy,HR 2.27(95%CI 1.20 to 4.32),p=0.012 and the presence of DVA,HR 2.08(95%CI 1.00 to 4.31),p=0.049 were factors associated with higher probability of post-SRS ***-SRS haemorrhage was symptomatic in 22 out of 381(5.8%)patients,presenting with transient(15/381)or permanent(7/381)neurological *** occurred in 11.1%(46/414)CCM and was responsible for transient neurological deficit in 3.9%(15/381)of the patients and permanent deficit in 1.1%(4/381)of the *** doses>13 Gy and CCM volume>0.7 cc were associated with increased risk of ARe.

关键词： doses haemorrhagic diagnosis

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Strong Suppression of Systemic Acquired Resistance in Arabidopsis by NRR is Dependent on its Ability to Interact with NPRland its Putative Repression Domain

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Molecular Plant 2008年第3期1卷 552-559页

作者： Mawsheng Chern Patrick e. Canlas Pamela C. ronald Department of Plant Pathology University of California Davis CA 95616 USA

Systemic Acquired Resistance （SAR） in plants confers lasting broad-spectrum resistance to pathogens and requires the phytohormone salicylic acid （SA）. Arabidopsis NPR1/NIM1 is a key regulator of the SAR response. Studies attempting to reveal the function of NPR1 and how it mediates SA signaling have led to isolation of two classes of proteins that interact with NPRI＂ the first class includes rice NRR, Arabidopsis NIMIN1, NIMIN2, and NIMIN3, and tobacco NIMIN2-1ike proteins; the second class belongs to TGA transcription factors. We have previously shown that overexpression of N RR in rice suppresses both basal and Xa21-mediated resistance. In order to test whether NRR affects SA-induced, NPRl-mediated SAR, we have transformed Arabidopsis with the rice NRR gene and tested its effects on the defense response. expression of NRR in Arabidopsis results in suppression of PR gene induction by SAR inducer and resistance to pathogens. These phenotypes are even more severe than those of the nprl-1 mutant. The ability of NRR to suppress PR gene induction and disease resistance is correlated with its ability to bind to NPR1 because two point mutations in NRR, which reduce NPR1 binding, fail to suppress NPR1. In contrast, wild-type and a mutant NRR, which still binds to NPR1 strongly, retain the ability to suppress the SAR response. Replacing the C-terminal 79 amino acids of NRR with the VP16 activation domain turns the fusion protein into a transcriptional co-activator. These results indicate that NRR binds to NPR1 in vivo in a protein complex to inhibit transcriptional activation of PR genes and that NRR contains a transcription repression domain for active repression.

关键词： NRR NPR1 SA SAR disease resistance.

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Rare case of tibial hemimelia,preaxial polydactyly,and club foot

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World Journal of Clinical Cases 2016年第12期4卷 401-408页

作者： Guinevere Granite John e Herzenberg ronald Wade Department of Anatomy and Neurobiology School of MedicineUniversity of Maryland Rubin Institute for Advanced Orthopedics Sinai Hospital of Baltimore Department of Anatomical Services University of Maryland

A seven-month old female presented with left tibial hemimelia(or congenital tibial aplasia; Weber type VIIb, Jones et al type 1a), seven-toed preaxial polydactyly, and severe club foot(congenital talipes equinovarus). Definitive amputation surgery disarticulated the lower limb at the knee. This case report describes the anatomical findings of a systematic post-amputation examination of the lower limb's superficial dissection, X-ray s, and computed to mography (CT) scans. From the X-rays and CT scans, we found curved and overlapping preaxial supernumerary toes, hypoplastic first metatarsal, lack of middle and distal phalanges in one supernumerary toe, three tarsal bones, hypoplastic middle phalanx and no distal phalanx for fourth toe, andno middle or distal phalanges for fifth toe. The fibula articulated with the anteromedial calcaneus and the tibia was completely absent. We identified numerous muscles and nerves in the superficial dissection that are described in the results section of the case report. Due to the rarity of this combination of anatomical findings, descriptions of such cases are very infrequent in the literature.

关键词： Club foot Congenital talipes equinovarus Preaxial polydactyly Tibial hemimelia Congenital tibial aplasia

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