973 resultados para Geotechnical mapping
Characterization of laser plasmas for interaction studies: Progress in time-resolved density mapping
Resumo:
Time-resolved probe interferometry was used to obtain complete density mapping of laser produced plasmas. The plasma was produced by symmetrical irradiation of thin targets, to be used for short pulse delayed interaction experiments. The progress in the plasma characterization due to the use of a picosecond pulse probe is reported, and the relative merits of different target designs are also discussed. The two-dimensional density maps obtained appear to be in substantial agreement with two-dimensional hydrodynamic code predictions.
Resumo:
Immunoreactive T lymphocyte epitopes within the ORF1, ORF2, and ORF 3 products of porcine circovirus type 2 (PCV2) were mapped. For this, overlapping linear 20-mer peptides were synthesized and tested for their ability to induce T lymphocyte proliferation in porcine peripheral blood mononuclear cells (PBMCs) isolated from experimentally PCV2-infected pigs. After a preliminary screening of 31 (ORF1), 23 (ORF2), and 10 (ORF3) peptides using PBMCs from 4 PCV2-infected pigs, none of the peptides appeared to be immunoreactive (stimulation index [SI] : 2) in all four pigs. Only 14 peptides appeared to be immunoreactive in 3 of the 4 pigs. These peptides were designated as immunodominant in the preliminary screening and selected for further analysis. The immunodominant peptides were resynthesized and purified by high-performance liquid chromatography and tested for their ability to induce T lymphocyte proliferation in PBMCs from another three PCV2-infected pigs. None of the immunodominant peptides appeared to be immunoreactive in all three pigs of the second screening. Only three peptides appeared to be immunoreactive in two of three pigs, two encoded by PCV2 ORF1 (amino acid residues 81-100 and 201-220) and one encoded by PCV2 ORF3 (amino acid residues 31-50), and were therefore considered to be immunodominant in both screenings. Although peptides encoded by ORF2 appeared to show the highest immunoreactivity in some pigs, none of these peptides displayed immunodominance in both screenings. In summary, the present study indicates that the T lymphocyte responses to PCV2 are primarily directed toward epitopes of the nonstructural proteins of ORF1 and ORF3.
Resumo:
The rapid proliferation of remote sensing and geographic information systems (GIS) into geomorphologic mapping has increased the objectivity and efficiency of landform segmentation, measurement, and classification. The near ubiquitous presence of Earth-observing satellites provides an array of perspectives to visualize the biophysical characteristics of landscapes, access inhospitable terrain on a predictable schedule, and study landscape processes when conditions are hazardous. GIS technology has altered the analysis, visualization, and dissemination of landform data due to the shared theoretical concepts that are fundamental to geomorphology and GIScience. The authors review geospatial technology applications in landform mapping (including emerging issues) within glacial, volcanic, landslide, and fluvial research.
Resumo:
Recently, considerable efforts have been made in the attempt to map quick clay areas using electrical resistivity measurements. However there is a lack of understanding regarding which soil parameters control the measured resistivity values. To address this issue, inverted resistivity values from 15 marine clay sites in Norway have been compared with basic geotechnical index properties. It was found that the resistivity value is strongly controlled by the salt content of the pore fluid. Resistivity decreases rapidly with increasing salt content. There is also a relatively clear trend of decreasing resistivity with increasing clay content and plasticity index. Resistivity values become very low (˜5 O·m) for high clay content (>50%), medium- to high-plasticity (Ip ˜ 20%) materials with salt content values greater than about 8 g/L (or corresponding remoulded shear strength values greater than 4 kPa). For the range of values studied, there is poor correlation between resistivity and bulk density and between resistivity and water content. The data studied suggest that the range of resistivity values corresponding to quick clay is 10 to 100 O·m, which is consistent with other published limits. A comparison is made between two-dimensional electrical resistivity tomography (ERT) and resistivity cone penetration test (RCPTU) data for two of the sites and the two sets of data show similar trends and values irrespective of scale effect.
Resumo:
Aims: To determine whether 80-lead body surface potential mapping (BSPM) improves detection of acute coronary artery occlusion in patients presenting with out-of-hospital cardiac arrest (OHCA) due to ventricular fibrillation (VF) and who survived to reach hospital. Methods and results: Of 645 consecutive patients with OHCA who were attended by the mobile coronary care unit, VF was the initial rhythm in 168 patients. Eighty patients survived initial resuscitation, 59 of these having had BSPM and 12-lead ECG post-return of spontaneous circulation (ROSC) and in 35 patients (age 69±13 yrs; 60% male) coronary angiography performed within 24. h post-ROSC. Of these, 26 (74%) patients had an acutely occluded coronary artery (TIMI flow grade [TFG] 0/1) at angiography. Twelve-lead ECG criteria showed ST-segment elevation (STE) myocardial infarction (STEMI) using Minnesota 9-2 criteria - sensitivity 19%, specificity 100%; ST-segment depression (STD) =0.05. mV in =2 contiguous leads - sensitivity 23%, specificity 89%; and, combination of STEMI or STD criteria - sensitivity 46%, specificity 100%. BSPM STE occurred in 23 (66%) patients. For the diagnosis of TFG 0/1 in a main coronary artery, BSPM STE had sensitivity 88% and specificity 100% (c-statistic 0.94), with STE occurring most commonly in either the posterior, right ventricular or high right anterior territories. Conclusion: Among OHCA patients presenting with VF and who survived resuscitation to reach hospital, post-resuscitation BSPM STE identifies acute coronary occlusion with sensitivity 88% and specificity 100% (c-statistic 0.94). © 2012 Elsevier Ireland Ltd.
Resumo:
The exposure of historic stone to processes of lichen-induced surface biomodification is determined, first and foremost, by the bioreceptivity of those surfaces to lichen colonization. As an important component of surface bioreceptivity, spatiotemporal variation in stone surface temperature plays a critical role in the spatial distribution of saxicolous lichen on historic stone structures, especially within seasonally hot environments. The ornate limestone and tufa stairwell of the Monastery of Cartuja (1516), Granada, Spain, exhibits significant aspect-related differences in lichen distribution. Lichen coverage and
diurnal fluctuations in stone surface temperature on the stairwell were monitored and mapped, under anticyclonic conditions in summer and winter, using an infrared thermometer and Geographical Information Systems approach. This research suggests that it is not extreme high surface temperatures that
determine the presence or absence of lichen coverage on stonework. Instead, average stone surface temperatures
over the course of the year seem to play a critical role in determining whether or not surfaces are receptive to lichen colonization and subsequent biomodification. It is inferred that lichen, capable of surviving extreme surface temperatures during the Mediterranean summer in an ametabolic state, require a respite period of lower temperatures within which they can metabolize, grow and reproduce.
The higher the average annual temperature a surface experiences, the shorter the respite period for any lichen potentially inhabiting that surface. A critical average temperature threshold of approximately 21 ?C has been identified on the stairwell, with average stone surface temperatures greater than this
generally inhibiting lichen colonization. A brief visual condition assessment between lichen-covered and lichen-free surfaces on the limestone sections of the stairwell suggests relative bioprotection induced by lichen coverage, with stonework quality and sharpness remaining more defined beneath lichen-covered surfaces. The methodology employed in this paper may have further applications in the monitoring and mapping of thermal stress fatigue on historic building materials.
Resumo:
We genotyped 2,861 cases of primary biliary cirrhosis (PBC) from the UK PBC Consortium and 8,514 UK population controls across 196,524 variants within 186 known autoimmune risk loci. We identified 3 loci newly associated with PBC (at P <5 × 10(-8)), increasing the number of known susceptibility loci to 25. The most associated variant at 19p12 is a low-frequency nonsynonymous SNP in TYK2, further implicating JAK-STAT and cytokine signaling in disease pathogenesis. An additional five loci contained nonsynonymous variants in high linkage disequilibrium (LD; r(2) > 0.8) with the most associated variant at the locus. We found multiple independent common, low-frequency and rare variant association signals at five loci. Of the 26 independent non-human leukocyte antigen (HLA) signals tagged on the Immunochip, 15 have SNPs in B-lymphoblastoid open chromatin regions in high LD (r(2) > 0.8) with the most associated variant. This study shows how data from dense fine-mapping arrays coupled with functional genomic data can be used to identify candidate causal variants for functional follow-up.
Resumo:
Bit-level systolic-array structures for computing sums of products are studied in detail. It is shown that these can be subdivided into two classes and that within each class architectures can be described in terms of a set of constraint equations. It is further demonstrated that high-performance system-level functions with attractive VLSI properties can be constructed by matching data-flow geometries in bit-level and word-level architectures.
Resumo:
This article summarizes the key findings from the five mapping case studies presented in this special issue and relates them back to the conceptual, definitional, and theoretical issues presented in the opening article (MacCarthaigh & Roness, 2012). In so doing, the article considers the alternative ways in which organizational change can best be captured, mapped, and explained and the key issues to be considered when conducting such exercises. As well as identifying how the case studies have advanced the possibilities for mapping public sector organizational change over time in a cross-national context and the benefits this offers for other aspects of public administration research, the article identifies some impediments to future research and collaboration in the field and suggests ways to overcome them. © Taylor & Francis Group, LLC.