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91.
92.
Nicholas King Asha Rajvanshi Selwyn Willoughby Ruben Roberts Vinod B. Mathur Mandy Cadman 《影响评估与项目评价》2013,31(3):148-156
Biodiversity information obtained during environmental impact assessments (EIAs) is rarely accessible for other uses following the completion of the EIA. Such data need to be made readily accessible; adding them to publicly accessible national datasets is important if biodiversity science, conservation and future decisions based on environmental assessment are to benefit from new biodiversity data and improved biodiversity data coverage. An ‘EIA Biodiversity Data Publishing Framework’, based on the Global Biodiversity Information Facility (GBIF) global standards, is thus proposed to meet this need. This paper outlines the GBIF-catalysed initiative to establish such an operational framework for uptake by the EIA community, as well as options that are available for data publishing in the absence of such a framework. It reviews the current state of accessibility and management of the primary biodiversity data associated with EIA studies, and highlights the urgent need for uptake of a range of data-publishing tools and best practices for making EIA biodiversity data exchangeable using globally accepted standards. Lessons learnt from pilot projects in India and South Africa underline the call for the rapid uptake of a national-to-global scale EIA Biodiversity Data Publishing Framework. 相似文献
93.
Negri AL Barone R Lombas C Bogado CE Zanchetta JR 《Hemodialysis international. International Symposium on Home Hemodialysis》2006,10(4):351-355
Several studies have suggested an increased prevalence of osteopenia in dialysis. Peripheral quantitative computed tomography (pQCT) is a new technique that allows the noninvasive evaluation of trabecular and cortical bone separately. The aim of the study was: (1) to evaluate cortical bone by pQCT in continuous ambulatory peritoneal dialysis (CAPD) patients and compare the data with that obtained in healthy controls; and (2) to correlate cortical bone parameters with bone mineral density (BMD) of the lumbar spine and femoral neck and total bone mineral content (TBMC). Cortical bone parameters were obtained in 22 CAPD patients and 27 healthy individuals at the distal radius using a Stratec XCT 960 pQCT machine. In the dialysis patients, we also determined BMD and TBMC by bone densitometry. Dialysis patients, compared with controls, showed a significant reduction in volumetric cortical BMD (VcBMD) (p = 0.04) and cortical thickness (cThk) (p < 0.0001) with a significant increase in radial total cross-sectional area (TA) (p = 0.006), endosteal circumference (p < 0.0001), and buckling ratio (p < 0.0001). In CAPD patients, total time on dialysis correlated negatively with radial total BMD (p < 0.01) and VcBMD (p < 0.01). Age correlated positively with TA (p < 0.01), endosteal (p < 0.01), and periosteal circumferences (p < 0.01). Serum intact parathyroid hormone (PTH) levels correlated positively with endosteal (p = 0.04) and periosteal perimeter (p = 0.01). Total alkaline phosphatase correlated negatively with VcBMD (p < 0.01), and positively with endosteal perimeter (p = 0.02). Total bone mineral content correlated significantly with radial cortical content (p < 0.001), cross-sectional cortical area (cA; p < 0.001), and cThk (p < 0.01) but not with total radial BMD, VcBMD, or buckling ratio. No correlations were found between radial cortical parameters and BMD measured at the lumbar spine or femoral neck. We conclude that dialysis patients show cortical osteopenia with marked cortical thinning partially mediated by PTH action on bone. Total bone mineral content correlated with various radial cortical parameters (content, area, and thickness) but not with others. No correlations were found between cortical bone parameters measured at the peripheral skeleton with areal bone density measured at the axial skeleton. These findings suggest that pQCT may be a new tool in the assessment of bone fragility in dialysis patients. 相似文献
94.
95.
Nanoscale compositional mapping with gentle forces 总被引:2,自引:0,他引:2
Microscopists have always pursued the development of an instrument that combines topography and materials properties analyses at the highest resolution. The measurement of the tiny amount of energy dissipated by a vibrating tip in the proximity of the sample surface has provided atomic force microscopes with a robust and versatile method to determine the morphology and the compositional variations of surfaces in their natural environment. Applications in biology, polymer science and microelectronics illustrate the potential of phase-imaging force microscopy for nanoscale analysis. 相似文献
96.
JM Greene YL Li PA Yourey J Gruber KC Carter BK Shell PA Dillon C Florence DR Duan A Blunt DM Ornitz SM Ruben RF Alderson 《Canadian Metallurgical Quarterly》1998,10(5):1911-1925
A new member of the fibroblast growth factor (FGF) family, FGF-13, has been molecularly cloned as a result of high throughput sequencing of a human ovarian cancer cell library. The open reading frame of the novel human gene (1419 bp) encodes for a protein of 216 a.a. with a molecular weight of 22 kDa. The FGF-13 sequence contains an amino-terminal hydrophobic region of 23 a.a. characteristic of a signal secretion sequence. FGF-13 is most homologous, 70% similarity at the amino acid level, to FGF-8. Northern hybridization analysis demonstrated prominent expression of FGF-13 in human foetal and adult brain, particularly in the cerebellum and cortex. In proliferation studies with BaF3 cells, FGF-13 preferentially activates cell clones expressing either FGF receptor variant, 3-IIIc or 4. The signal transduction pathways of FGF-13 and FGF-2 were compared in rat hippocampal astrocytes. The two FGFs induce an equivalent level of tyrosine phosphorylation of mitogen-activated protein kinase (MAPK) and c-raf activation. However, FGF-13 is more effective than FGF-2 in inducing the phosphorylation of phospholipase C-gamma (PLC-gamma). Treatment of neuronal cultures from rat embryonic cortex with FGF-13 increases the number of glutamic acid decarboxylase immunopositive neurons, the level of high-affinity gamma-aminobutyric acid (GABA) uptake, and choline acetyltransferase enzyme activity. The GABAergic neuronal response to FGF-13 treatment is rapid with a significant increase occurring within 72 h. We have identified a novel member of the FGF family that is expressed in the central nervous system (CNS) and increases the number as well as the level of phenotypic differentiation of cortical neurons in vitro. 相似文献
97.
Targeting sites that modulate protein-protein interactions represents an ongoing challenge for drug discovery. We have devised an assay principle, named ligand-regulated competition (LiReC), in an effort to find non-ATP competitive small-molecule regulators for type Ialpha cAMP-dependent Protein kinase (PKA-Ialpha), a protein complex that is implicated in disease. Our assay based on the LiReC principle utilizes a competitive fluorescent peptide probe to assess the integrity of the PKA-Ialpha complex upon introduction of an allosteric ligand. The developed fluorescence polarization method screens for small molecules that specifically protect (antagonists) or conversely activate (agonists) this protein complex. In high-throughput format, various cyclic nucleotide-derived agonists and antagonists are successfully detected with high precision. Furthermore, assay performance (Z'-factors above 0.7) far exceeds the minimum requirement for small-molecule screening. To identify compounds that operate through novel modes of action, our method shields the ATP-binding site and purposely excludes ATP-competitive ligands. These proof-of-principle experiments highlight the potential of the LiReC technique and suggest its application to other protein complexes, thereby providing a novel approach to identify and characterize modulators (small molecules, proteins, peptides, or nucleic acids) of protein-protein systems. 相似文献
98.
Minoru Takahashi Koichiro Adachi Ruben L. Menchavez Masayoshi Fuji 《Journal of Materials Science》2006,41(7):1965-1972
In this study, we propose a new process to fabricate electrically semi-conductive alumina by the combination of gelcasting
and reduction sintering. The process is similar to the conventional gelcasting method except for varying amounts of methacrylamide
monomer dosages at 2.83, 5.50, and 8.04 wt% relative to the mass of the slurry. Correspondingly, the rheological evaluation
of aqueous slurry was conducted. The resulting fluidity exhibited that monomer dosage until 8.04 wt% yielded slurry viscosity
of 1628 MPA·s at shear rate of 20 s−1, which was feasible for gelcasting without noticeable casting defects. The freshly gelled bodies were demolded, carefully
dried, and then sintered at different schedules in nitrogen atmosphere. The reduction-sintered samples were re-sintered in
air for comparative evaluation of physical property. The sintered alumina body was characterized by electrical resistance,
X-ray diffraction, and scanning electron microscopy. The results showed that monomer additions and sintering schedule significantly
affect in lowering electrical resistivity. The obtained lowest value was 3.6 × 106 Ω-cm with 8.04 wt% monomer dosage and sintering at 1550°C with 2 h holding time. The resulting material is classified as
semi-conductive, which is potential for electrostatic shielding applications. The effect of physical property and microstructure
on electrical conductivity and the corresponding reaction mechanism were discussed in details. 相似文献
99.
Exact 3D boundary representation in finite element analysis based on Cartesian grids independent of the geometry 下载免费PDF全文
Onofre Marco Ruben Sevilla Yongjie Zhang Juan José Ródenas Manuel Tur 《International journal for numerical methods in engineering》2015,103(6):445-468
This paper proposes a novel Immersed Boundary Method where the embedded domain is exactly described by using its Computer‐Aided Design (CAD) boundary representation with Non‐Uniform Rational B‐Splines (NURBS) or T‐splines. The common feature with other immersed methods is that the current approach substantially reduces the burden of mesh generation. In contrast, the exact boundary representation of the embedded domain allows to overcome the major drawback of existing immersed methods that is the inaccurate representation of the physical domain. A novel approach to perform the numerical integration in the region of the cut elements that is internal to the physical domain is presented and its accuracy and performance evaluated using numerical tests. The applicability, performance, and optimal convergence of the proposed methodology is assessed by using numerical examples in three dimensions. It is also shown that the accuracy of the proposed methodology is independent on the CAD technology used to describe the geometry of the embedded domain. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
100.
Sheets made from readily available conventional materials containing diamond or star shaped perforations are shown to exhibit various Poisson's ratio values which could also be negative (auxetic). This behavior may be exhibited in both tension and compression and can be explained through models based on “rotating rigid units.” This provides an easy manner for the manufacture of auxetic or conventional systems at any scale which can be tailor made to exhibit particular values of the Poisson's ratio. 相似文献