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Influence of Ice on Soil Elemental Characterization via Portable X-Ray Fluorescence Spectrometry

Pedosphere 2014年第1期24卷 1-12页

作者： D.C.WEINDORF N.BAKR Y.ZHU A.MCWHIRT C.L.PINg g.michaelson C.NELSON K.SHOOK S.NUSS Texas Tech University Department of Plant and Soil Sciences Louisiana State University Agricultural Center University of Alaska Fairbanks Palmer Research Center

Field portable X-ray fluorescence （PXRF） spectrometry has become an increasingly popular technique for in-situ elemental characterization of soils. The technique is fast, portable, and accurate, requiring minimal sample preparation and no consumables. However, soil moisture 〉 20% has been known to cause fluorescence denudation and error in elemental reporting and few studies have evaluated the presence of soil moisture in solid form as ice. gelisols （USDA Soil Taxonomy）, permafrost-affected soils, cover a large amount of the land surface in the northern and southern hemispheres. Thus, the applicability of PXRF in those areas requires further investigation. PXRF was used to scan the elemental composition （Ba, Ca, Cr, Fe, K, Mn, Pb, Rb, Sr, Ti, Zn, and Zr） of 13 pedons in central and northern Alaska, USA. Four types of scans were completed： 1） in-situ frozen soil, 2） re-frozen soil in the laboratory, 3） melted soil/water mixture in the laboratory, and 4） moisture-corrected soil. All were then compared to oven dry soil scans. Results showed that the majority of PXRF readings from in-situ, re-frozen, and melted samples were significantly underestimated, compared to the readings on oven dry samples, owing to the interference expected by moisture. However, when the moisture contents were divided into 〉 40% and 〈 40〈 groups, the PXRF readings under different scanning conditions performed better in the group with 〈 40% moisture contents. Most elements of the scans on the melted samples with 〈 40% moisture contents acceptably compared to those of the dry samples, with R2 values ranging from 0.446 （Mn） to 0.930 （St）. However, underestimation of the melted samples was still quite apparent. Moisture-corrected sample PXRF readings provided the best correlation to those of the dry, ground samples as indicated by higher R2 values, lower root mean square errors （RMSEs）, and slopes closer to 1 in linear regression equations. However, the in-situ （frozen） sample scans did not differ

关键词： gelisols moisture permafrost proximal sensing regression

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SURVIVAL TRENDS IN CHILDHOOD HEMATOLOgICAL MALIgNANCIES

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International Journal of Biomathematics 2012年第6期5卷 95-103页

作者： STEPHANIE RICH SHIHAB ALI gEOFFREY W. CALKINS JAMES S. michaelson Laboratory of Quantitative Medicine Massachusetts general Hospital 65 Landsdowne Street Suite 200Cambridge Massachusetts 02139 USA Laboratory of Quantitative Medicine and Departments of Surgery and Pathology Massachusetts general Hospital 65 Landsdowne Street Suite 200Cambridge Massachusetts 02139 USA

Survival of patients with childhood hematological malignancies has increased markedly in the past decades. To examine the finescale details of how this progress has occurred, we carried out KaplanMeier causespecific survival analysis using the Surveillance Epi demiology and End Results （SEER） dataset for patients with childhood hematologi cal malignancies Hodgkin＇s Lymphoma, NonHodgkin＇s Lymphoma, Lymphoblastic Leukemia and Myeloid Leukemia diagnosed in five eras： 1983-1987; 1988-1992; 1993-1997; 1998-2002 and 2003-2007. We generated KaplanMeier estimates of survival for each of the first 24 years after diagnosis. These figures agree with previously reported five and tenyear values and attest to the remarkable increase in survival that has occurred over the past three decades of medical progress. The trend towards progres sively increasing survival shows no sign of slowing, suggesting that we may expect further increases in survival in the years ahead. Most of the increase in survival for childhood hematological malignancies has occurred by reducing the risk of death in the first two years after diagnosis. This may be largely explained by the fact that this is the time period when patients are at highest risk of death.

关键词： Childhood hematological malignancies survival trends.

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In-Situ Differentiation of Acidic and Non-Acidic Tundra via Portable X-ray Fluorescence (PXRF) Spectrometry

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Pedosphere 2016年第4期26卷 549-560页

作者： Somsubhra CHAKRABORTY David C. WEINDORF gARY J. michaelson Chien Lu PINg Ashok CHOUDHURY Tarek KANDAKJI Autumn ACREE Akriti SHARMA WANg Dandan Uttar Banga Krishi Viswavidyalaya Cooch Behar 736165 Department of Plant and Soil Science Texas Tech University Lubbock TX 79409 University of Alaska Fairbanks Palmer Research Center Palmer AK 99645 Louisiana State University Agricultural Center Baton Rouge LA 70803 College of geography and Remote Sensing Nanjing University of Information Science and Technology Nanjing 210044

Frozen soils or those with permafrost cover large areas of the earth's surface and support unique vegetative ecosystems. Plants growing in such harsh conditions have adapted to small niches, which allow them to survive. In northern Alaska, USA, both moist acidic and non-acidic tundra occur, yet determination of frozen soil p Hs currently requires thawing of the soil so that electrometric pH methods can be utilized. Contrariwise, a portable X-ray fluorescence(PXRF) spectrometer was used in this study to assess elemental abundances and relate those characteristics to soil pH through predictive multiple linear regressions. Two operational modes, Soil Mode and geochem Mode, were utilized to scan frozen soils in-situ and under laboratory conditions, respectively, after soil samples were dried and ground. Results showed that lab scanning produced optimal results with adjusted coefficient of determination(R^2) of 0.88 and 0.33 and root mean squared errors(RMSEs) of 0.87 and 0.34 between elemental data and lab-determined pH for Soil Mode and geochem Mode, respectively. Even though the presence of ice attenuated fluoresced radiation under field conditions, adjusted R^2 and RMSEs between the datasets still provided reasonable model generalization(e.g., 0.73 and 0.49 for field geochem Mode). Principal component analysis qualitatively separated multiple sampling sites based on elemental data provided by PXRF, reflecting differences in the chemical composition of the soils studied. Summarily, PXRF can be used for in-situ determination of soil pH in arctic environments without the need for sample modification and thawing. Furthermore, use of PXRF for determination of soil pH may provide higher sample throughput than traditional eletrometric-based methods, while generating elemental data useful for the prediction of multiple soil parameters.

关键词： frozen soil gelisols geochem Mode proximal sensing Soil Mode soil pH determination

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Soil Pedon Carbon and Nitrogen Data for Alaska: An Analysis and Update

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Open Journal of Soil Science 2013年第2期3卷 132-142页

作者： gary J. michaelson Chien-Lu Ping Mark Clark Agriculture and Forestry Experiment Station University of Alaska Fairbanks Palmer Research Center Palmer USA USDA- Natural Resources Conservation Service Palmer USA

We combined C and N related pedon data from the USDA-NRCS National Cooperative Soil Survey Soil Characterization Database with data from the University of Alaska Fairbanks (UAF) northern soils research program, representing 58 and 30 years of field work, respectively. Carbon and N data from 117 UAF pedons were added to 541 pedons from the USDA-NRCS data set for a total of 658. Missing carbon (C), nitrogen (N) and related data were added to nearly all of the USDA-NRCS Arctic region pedons from unpublished UAF data. We present relationships among soil parameters of the data set that are necessary for calculation of pedon soil organic C and N stores. These new relationships are necessary for better estimating missing soil bulk density (Db) from measured soil organic C by high-temperature combustion (SOCHTC) and for conversion of acid chromate reduction soil organic carbon (SOCACR) to SOCHTC. For the USDA-NRCS data, missing Db data were estimated and SOCACR corrected to SOCHTC using the new functional relationships developed. This allowed for pedon SOC and N stores to be calculated for 609 and 468 Alaska pedons respectively, the most available to-date. Additionally, functional relationships were developed for data within soil orders to estimate total SOCHTC and N stores in pedons with missing surface organic horizons where only thicknesses were known. These relationships are presented in order to fill-in missing data and to better define the existing data set for future use. Some 1904 missing Db data points and 1612 corrected SOCHTC data points were added to the total of 4240 points in the 609 pedons that constitute the updated dataset. When O-layer thickness functions developed here were used, SOC and N stores were calculated for an additional 137 and 184 pedons respectively.

关键词： Soil Carbon Soil Nitrogen Arctic Soils Pedotransfer Functions Permafrost Soils

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全身微波(2450MHz)照射对植入乳腺腺癌大鼠的肿瘤生长和存活率影响的研究

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中山大学学报(医学科学版) 1987年第1期 47-54页

作者：陈成章,Sol.M.michaelson 中山医科大学预防医学研究所环境医学研究室美国纽约州罗彻斯特大学医学与牙科学院放射生物学和生物物理系

微波对肿瘤生长影响的研究已有30多年的历史,几乎所有的研究报告都证明单次或多次的微波局部照射都可能引起肿瘤的退化。有关2450MHz微波使组织产热的模型的研究始于1962(Lehmenn et al),至1976年才有2450MHz微波局部照射对带肿瘤动物... 详细信息

微波对肿瘤生长影响的研究已有30多年的历史,几乎所有的研究报告都证明单次或多次的微波局部照射都可能引起肿瘤的退化。有关2450MHz微波使组织产热的模型的研究始于1962(Lehmenn et al),至1976年才有2450MHz微波局部照射对带肿瘤动物影响的报告(Mendecki et al 1976)。

关键词：肿瘤生长大鼠乳腺腺癌微波电磁波实验动物全身 MHz

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微波全身照射对带肿瘤和非带肿瘤大鼠免疫反应的影响

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职业医学 1989年第3期16卷 6-9页

作者：陈成章 Sol.M.michaelson 中山医科大学预防医学研究所环境医学研究所美国纽约州罗彻斯特大学医学与牙科学院放射生物与生物物理系

雌性Fisher 344大鼠照射2450MHz微波(10、20和40mW/cm^2;SAR=3.4、6.8和13.6mW/g)两周,每周5天,每天3小时。带植入乳腺腺癌R-3230 AC动物,照射后脾脏有核细胞密度和血清Igg含量与照射功率密度呈负的剂量—效应关系;外周血非PHA刺激的淋... 详细信息

雌性Fisher 344大鼠照射2450MHz微波(10、20和40mW/cm^2;SAR=3.4、6.8和13.6mW/g)两周,每周5天,每天3小时。带植入乳腺腺癌R-3230 AC动物,照射后脾脏有核细胞密度和血清Igg含量与照射功率密度呈负的剂量—效应关系;外周血非PHA刺激的淋巴细胞转化与功率密度呈正的剂量—效应关系。非带肿瘤动物无上述剂量—效应关系出现。说明带肿瘤动物的免疫系统对微波照射反应的敏感性高于非带肿瘤动物,前者的细胞和体液免疫反应均出现变化,意义有待查明。

关键词：微波脾脏有核细胞密度免疫球蛋白g 乳腺腺癌R-3230AC

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一例转移性肾细胞癌病例分析

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中国处方药 2008年第6期7卷 82-83页

作者： M. Dror michaelson Othon Iliopoulos David F. McDermott 黄艳（编译）

一例63岁患者因左肾肿块和肺部结节入院。入院前5个月身体状况良好，之后陆续出现轻微恶心、食欲不振、腹痛和便秘，随后出现容易疲劳、体重下降3．2kg、不明原因的咳嗽。入院前1个月，患者在社区医院就诊，发现双下肢静脉曲张（以前检... 详细信息

一例63岁患者因左肾肿块和肺部结节入院。入院前5个月身体状况良好，之后陆续出现轻微恶心、食欲不振、腹痛和便秘，随后出现容易疲劳、体重下降3．2kg、不明原因的咳嗽。入院前1个月，患者在社区医院就诊，发现双下肢静脉曲张（以前检查中就有该现象）和阴囊精索静脉曲张，其余无异常。实验室检查和影像学检查均正常。腹部CT发现在左肾下盏有肿块，

关键词：转移性肾细胞癌病例分析影像学检查精索静脉曲张下肢静脉曲张右肾上腺肾肿块实验室检查

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爱你的方式

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疯狂英语（初中天地） 2012年第8期 7-7页

作者： Ingrid michaelson 思苇

你若跌倒我会把你接住你需要光亮时我会找火柴因为我喜欢你道早安的调调而你接受了这样的我

关键词：中学英语教学教学方法阅读教学

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穿通性角膜移植物

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中华眼科杂志 1956年第5期 470-470页

作者： michaelson.I.C. 唐秀民

根据作者自己的經驗認为,虽然施術者怎样有意識地使环鑽垂直,仍旧是持定环鑽的手的位置,來决定环鑽進入前房第一个穿孔的子午線。这个事实是值得注意的;作者叙述有两种情况,就恰当地应用了这个事实。当移植片快要盖上虹膜前粘連的时候,...

根据作者自己的經驗認为,虽然施術者怎样有意識地使环鑽垂直,仍旧是持定环鑽的手的位置,來决定环鑽進入前房第一个穿孔的子午線。这个事实是值得注意的;作者叙述有两种情况,就恰当地应用了这个事实。当移植片快要盖上虹膜前粘連的时候,需要巧妙地运行刀口,以使粘連恰在第一个穿通处發生。这种办法使粘連較比容易切断,並且能更好地保护晶狀体。

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