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1.
The RAINFOR database: monitoring forest biomass and dynamics 总被引:1,自引:0,他引:1
Problem: Data from over 100 permanent sample plots which have been studied for 10–20 years need a suitable system for storage which allows simple data manipulation and retrieval for analysis. Methods: A relational database linking tree records, taxonomic nomenclature and corresponding environmental data has been built in MS Access as part of the RAINFOR project. Conclusion: The database allows flexible and long‐term use of a large amount of data: more than 100 tree plots across Amazonia, incorporating over 80 000 records of individual trees and over 300 000 total records of tree diameter measurements from successive censuses. The database is designed to enable linkages to existing soil, floristic or plant‐trait databases. This database will be a useful tool for exploring the impact of environmental factors on forest structure and dynamics at local to continental scales, and long term changes in forest ecology. As an early example of its potential, we explore the impact of different methodological assumptions on estimates of tropical forest biomass and carbon storage. 相似文献
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E K Lund M W Smith M A Peacock 《Comparative biochemistry and physiology. A, Comparative physiology》1986,85(1):175-181
The influence of parental spleen cells on the postnatal development of brush border microvillus membrane structure and the ability to transport lysine and alanine has been studied in the mouse jejunum during the second week of postnatal life. Control tissue taken from 7-11 day old mice has an unchanging crypt-villus structure and a low enterocyte migration rate of about 1 micron hr-1. Microvillus elongation in crypt enterocytes takes 6 days to complete under these conditions. Lysine and alanine transport begin 2 days after structural differentiation has ceased. Parental spleen cells injected into 1-2-day-old F1 mice cause crypt cell hyperplasia, villus shortening and a 3-6-fold increase in enterocyte migration rate after a period of 8 days. These effects are associated with large reductions in the time needed to complete microvillus membrane development and first express absorptive function. Lysine and alanine transport begin approximately 6 hr after structural differentiation has ceased under these conditions. Adaptive changes in the development of enterocyte structure and function, induced by injection of parental spleen cells, bear some resemblance to other changes found to occur normally at weaning and in adult animals subjected to controlled changes in diet and environmental temperature. The possibility that common principles govern enterocyte adaptation and that some of these still apply in an intestine undergoing an immune reaction is discussed. 相似文献
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Human Brain Microvascular Endothelial Cells Derived from the BC1 iPS Cell Line Exhibit a Blood-Brain Barrier Phenotype 总被引:1,自引:0,他引:1
The endothelial cells that form capillaries in the brain are highly specialized, with tight junctions that minimize paracellular transport and an array of broad-spectrum efflux pumps that make drug delivery to the brain extremely challenging. One of the major limitations in blood-brain barrier research and the development of drugs to treat central nervous system diseases is the lack of appropriate cell lines. Recent reports indicate that the derivation of human brain microvascular endothelial cells (hBMECs) from human induced pluripotent stem cells (iPSCs) may provide a solution to this problem. Here we demonstrate the derivation of hBMECs extended to two new human iPSC lines: BC1 and GFP-labeled BC1. These hBMECs highly express adherens and tight junction proteins VE-cadherin, ZO-1, occludin, and claudin-5. The addition of retinoic acid upregulates VE-cadherin expression, and results in a significant increase in transendothelial electrical resistance to physiological values. The permeabilities of tacrine, rhodamine 123, and Lucifer yellow are similar to values obtained for MDCK cells. The efflux ratio for rhodamine 123 across hBMECs is in the range 2–4 indicating polarization of efflux transporters. Using the rod assay to assess cell organization in small vessels and capillaries, we show that hBMECs resist elongation with decreasing diameter but show progressive axial alignment. The derivation of hBMECs with a blood-brain barrier phenotype from the BC1 cell line highlights that the protocol is robust. The expression of GFP in hBMECs derived from the BC1-GFP cell line provides an important new resource for BBB research. 相似文献
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Jonas G. Barlind Linda K. Buckett Sharon G. Crosby Öjvind Davidsson Hans Emtenäs Anne Ertan Ulrik Jurva Malin Lemurell Pablo Morentin Gutierrez Karolina Nilsson Gavin O’Mahony Annika U. Petersson Alma Redzic Fredrik Wågberg Zhong-Qing Yuan 《Bioorganic & medicinal chemistry letters》2013,23(9):2721-2726
[Acyl CoA]monoacylglycerol acyltransferase 2 (MGAT2) is of interest as a target for therapeutic treatment of diabetes, obesity and other diseases which together constitute the metabolic syndrome. In this Letter we report our discovery and optimisation of a novel series of MGAT2 inhibitors. The development of the SAR of the series and a detailed discussion around some key parameters monitored and addressed during the lead generation phase will be given. The in vivo results from an oral lipid tolerance test (OLTT) using the MGAT2 inhibitor (S)-10, shows a significant reduction (68% inhibition relative to na?ve, p <0.01) in plasma triacylglycerol (TAG) concentration. 相似文献
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The healthcare of people with HIV is transitioning from specialty care to the primary healthcare (PHC) system. However, many of the performance indicators used to measure the quality of HIV care pre-date this transition. The goal of this work was to examine how existing HIV care performance indicators measure the comprehensive and longitudinal care offered in a PHC setting. A scoping review consisting of peer-reviewed and grey literature searches was performed. Two reviewers evaluated study eligibility and indicators in documents meeting inclusion criteria were extracted into a database. Indicators were matched to a PHC performance measurement framework to determine their applicability for evaluating quality of care in the PHC setting. The literature search identified 221 publications, of which 47 met inclusion criteria. 1184 indicators were extracted and removal of duplicates left 558 unique indicators. A majority of the 558 indicators fell under the ‘secondary prevention’ (12%) and ‘care of chronic conditions’ (33%) domains when indicators were matched to the PHC performance framework. Despite the imbalance, nearly all performance domains in the PHC framework were populated by at least one indicator with significant concentrations in domains such as patient-provider relationship, patient satisfaction, population and community characteristics, and access to care. Existing performance frameworks for the care of people with HIV provide a comprehensive set of indicators that align well with a PHC performance framework. Nonetheless, some important elements of care, such as patient-reported outcomes, are poorly covered by existing indicators. Advancing our understanding of how the experience of care for people with HIV is impacted by changes in health services delivery, specifically more care within the PHC system, will require performance indicators to capture this aspect of HIV care. 相似文献