WorldWideScience

Sample records for admixture mapping scans

  1. Prospects for Admixture Mapping of Complex Traits

    OpenAIRE

    McKeigue, Paul M

    2004-01-01

    Admixture mapping extends to human populations the principles that underlie linkage analysis of an experimental cross. For detecting genes that contribute to ethnic variation in disease risk, admixture mapping has greater statistical power than family-linkage studies. In comparison with association studies, admixture mapping requires far fewer markers to search the genome and is less affected by allelic heterogeneity. Statistical-analysis programs for admixture mapping are now available, and ...

  2. Admixture as the basis for genetic mapping

    OpenAIRE

    Buerkle, C. Alex; Lexer, Christian

    2008-01-01

    Genetic mapping in natural populations is increasing rapidly in feasibility and accessibility. As with many areas in genetics, advances in molecular techniques and statistics are drastically altering how we can investigate inheritance in wild organisms. For ecology and evolution, this is particularly significant and promising, because many of the organisms of interest are not amenable to conventional genetic approaches. Admixture mapping falls within a family of statistical approaches that us...

  3. A genomewide admixture mapping panel for Hispanic/Latino populations.

    Science.gov (United States)

    Mao, Xianyun; Bigham, Abigail W; Mei, Rui; Gutierrez, Gerardo; Weiss, Ken M; Brutsaert, Tom D; Leon-Velarde, Fabiola; Moore, Lorna G; Vargas, Enrique; McKeigue, Paul M; Shriver, Mark D; Parra, Esteban J

    2007-06-01

    Admixture mapping (AM) is a promising method for the identification of genetic risk factors for complex traits and diseases showing prevalence differences among populations. Efficient application of this method requires the use of a genomewide panel of ancestry-informative markers (AIMs) to infer the population of origin of chromosomal regions in admixed individuals. Genomewide AM panels with markers showing high frequency differences between West African and European populations are already available for disease-gene discovery in African Americans. However, no such a map is yet available for Hispanic/Latino populations, which are the result of two-way admixture between Native American and European populations or of three-way admixture of Native American, European, and West African populations. Here, we report a genomewide AM panel with 2,120 AIMs showing high frequency differences between Native American and European populations. The average intermarker genetic distance is ~1.7 cM. The panel was identified by genotyping, with the Affymetrix GeneChip Human Mapping 500K array, a population sample with European ancestry, a Mesoamerican sample comprising Maya and Nahua from Mexico, and a South American sample comprising Aymara/Quechua from Bolivia and Quechua from Peru. The main criteria for marker selection were both high information content for Native American/European ancestry (measured as the standardized variance of the allele frequencies, also known as "f value") and small frequency differences between the Mesoamerican and South American samples. This genomewide AM panel will make it possible to apply AM approaches in many admixed populations throughout the Americas. PMID:17503334

  4. African Ancestry Analysis and Admixture Genetic Mapping for Proliferative Diabetic Retinopathy in African Americans

    Science.gov (United States)

    Tandon, Arti; Chen, Ching J.; Penman, Alan; Hancock, Heather; James, Maurice; Husain, Deeba; Andreoli, Christopher; Li, Xiaohui; Kuo, Jane Z.; Idowu, Omolola; Riche, Daniel; Papavasilieou, Evangelia; Brauner, Stacey; Smith, Sataria O.; Hoadley, Suzanne; Richardson, Cole; Kieser, Troy; Vazquez, Vanessa; Chi, Cheryl; Fernandez, Marlene; Harden, Maegan; Cotch, Mary Frances; Siscovick, David; Taylor, Herman A.; Wilson, James G.; Reich, David; Wong, Tien Y.; Klein, Ronald; Klein, Barbara E. K.; Rotter, Jerome I.; Patterson, Nick; Sobrin, Lucia

    2015-01-01

    Purpose. To examine the relationship between proportion of African ancestry (PAA) and proliferative diabetic retinopathy (PDR) and to identify genetic loci associated with PDR using admixture mapping in African Americans with type 2 diabetes (T2D). Methods. Between 1993 and 2013, 1440 participants enrolled in four different studies had fundus photographs graded using the Early Treatment Diabetic Retinopathy Study scale. Cases (n = 305) had PDR while controls (n = 1135) had nonproliferative diabetic retinopathy (DR) or no DR. Covariates included diabetes duration, hemoglobin A1C, systolic blood pressure, income, and education. Genotyping was performed on the Affymetrix platform. The association between PAA and PDR was evaluated using logistic regression. Genome-wide admixture scanning was performed using ANCESTRYMAP software. Results. In the univariate analysis, PDR was associated with increased PAA (odds ratio [OR] = 1.36, 95% confidence interval [CI] = 1.16–1.59, P = 0.0002). In multivariate regression adjusting for traditional DR risk factors, income and education, the association between PAA and PDR was attenuated and no longer significant (OR = 1.21, 95% CI = 0.59–2.47, P = 0.61). For the admixture analyses, the maximum genome-wide score was 1.44 on chromosome 1. Conclusions. In this largest study of PDR in African Americans with T2D to date, an association between PAA and PDR is not present after adjustment for clinical, demographic, and socioeconomic factors. No genome-wide significant locus (defined as having a locus-genome statistic > 5) was identified with admixture analysis. Further analyses with even larger sample sizes are needed to definitively assess if any admixture signal for DR is present. PMID:26098467

  5. Statistical Tests for Admixture Mapping with Case-Control and Cases-Only Data

    OpenAIRE

    Montana, Giovanni; Pritchard, Jonathan K

    2004-01-01

    Admixture mapping is a promising new tool for discovering genes that contribute to complex traits. This mapping approach uses samples from recently admixed populations to detect susceptibility loci at which the risk alleles have different frequencies in the original contributing populations. Although the idea for admixture mapping has been around for more than a decade, the genomic tools are only now becoming available to make this a feasible and attractive option for complex-trait mapping. I...

  6. Admixture Mapping Identifies a Quantitative Trait Locus Associated with FEV1/FVC in the COPDGene Study

    OpenAIRE

    Parker, Margaret M.; Foreman, Marilyn G; Abel, Haley J.; Rasika A Mathias; Hetmanksi, Jacqueline B.; Crapo, James D.; Silverman, Edwin K.; Terri H Beaty

    2014-01-01

    African Americans are admixed with genetic contributions from European and African ancestral populations. Admixture mapping leverages this information to map genes influencing differential disease risk across populations. We performed admixture and association mapping in 3300 African American current or former smokers from the COPDGene Study. We analyzed estimated local ancestry and SNP genotype information to identify regions associated with FEV1/FVC, the ratio of forced expiratory volume in...

  7. Admixture mapping identifies introgressed genomic regions in North American canids.

    Science.gov (United States)

    vonHoldt, Bridgett M; Kays, Roland; Pollinger, John P; Wayne, Robert K

    2016-06-01

    Hybrid zones typically contain novel gene combinations that can be tested by natural selection in a unique genetic context. Parental haplotypes that increase fitness can introgress beyond the hybrid zone, into the range of parental species. We used the Affymetrix canine SNP genotyping array to identify genomic regions tagged by multiple ancestry informative markers that are more frequent in an admixed population than expected. We surveyed a hybrid zone formed in the last 100 years as coyotes expanded their range into eastern North America. Concomitant with expansion, coyotes hybridized with wolves and some populations became more wolflike, such that coyotes in the northeast have the largest body size of any coyote population. Using a set of 3102 ancestry informative markers, we identified 60 differentially introgressed regions in 44 canines across this admixture zone. These regions are characterized by an excess of exogenous ancestry and, in northeastern coyotes, are enriched for genes affecting body size and skeletal proportions. Further, introgressed wolf-derived alleles have penetrated into Southern US coyote populations. Because no wolves currently exist in this area, these alleles are unlikely to have originated from recent hybridization. Instead, they probably originated from intraspecific gene flow or ancient admixture. We show that grey wolf and coyote admixture has far-reaching effects and, in addition to phenotypically transforming admixed populations, allows for the differential movement of alleles from different parental species to be tested in new genomic backgrounds. PMID:27106273

  8. Genome-wide Scan of 29,141 African Americans Finds No Evidence of Directional Selection since Admixture

    OpenAIRE

    Bhatia, Gaurav; Tandon, Arti; Patterson, Nick; Aldrich, Melinda C.; Ambrosone, Christine B.; Amos, Christopher; Bandera, Elisa V.; Berndt, Sonja I.; Bernstein, Leslie; Blot, William J.; Bock, Cathryn H.; Caporaso, Neil; Casey, Graham; Deming, Sandra L.; Diver, W. Ryan

    2014-01-01

    The extent of recent selection in admixed populations is currently an unresolved question. We scanned the genomes of 29,141 African Americans and failed to find any genome-wide-significant deviations in local ancestry, indicating no evidence of selection influencing ancestry after admixture. A recent analysis of data from 1,890 African Americans reported that there was evidence of selection in African Americans after their ancestors left Africa, both before and after admixture. Selection afte...

  9. Regional admixture mapping and structured association testing: conceptual unification and an extensible general linear model.

    Directory of Open Access Journals (Sweden)

    David T Redden

    2006-08-01

    Full Text Available Individual genetic admixture estimates, determined both across the genome and at specific genomic regions, have been proposed for use in identifying specific genomic regions harboring loci influencing phenotypes in regional admixture mapping (RAM. Estimates of individual ancestry can be used in structured association tests (SAT to reduce confounding induced by various forms of population substructure. Although presented as two distinct approaches, we provide a conceptual framework in which both RAM and SAT are special cases of a more general linear model. We clarify which variables are sufficient to condition upon in order to prevent spurious associations and also provide a simple closed form "semiparametric" method of evaluating the reliability of individual admixture estimates. An estimate of the reliability of individual admixture estimates is required to make an inherent errors-in-variables problem tractable. Casting RAM and SAT methods as a general linear model offers enormous flexibility enabling application to a rich set of phenotypes, populations, covariates, and situations, including interaction terms and multilocus models. This approach should allow far wider use of RAM and SAT, often using standard software, in addressing admixture as either a confounder of association studies or a tool for finding loci influencing complex phenotypes in species as diverse as plants, humans, and nonhuman animals.

  10. Development of admixture mapping panels for African Americans from commercial high-density SNP arrays

    Directory of Open Access Journals (Sweden)

    Dunston Georgia M

    2010-07-01

    Full Text Available Abstract Background Admixture mapping is a powerful approach for identifying genetic variants involved in human disease that exploits the unique genomic structure in recently admixed populations. To use existing published panels of ancestry-informative markers (AIMs for admixture mapping, markers have to be genotyped de novo for each admixed study sample and samples representing the ancestral parental populations. The increased availability of dense marker data on commercial chips has made it feasible to develop panels wherein the markers need not be predetermined. Results We developed two panels of AIMs (~2,000 markers each based on the Affymetrix Genome-Wide Human SNP Array 6.0 for admixture mapping with African American samples. These two AIM panels had good map power that was higher than that of a denser panel of ~20,000 random markers as well as other published panels of AIMs. As a test case, we applied the panels in an admixture mapping study of hypertension in African Americans in the Washington, D.C. metropolitan area. Conclusions Developing marker panels for admixture mapping from existing genome-wide genotype data offers two major advantages: (1 no de novo genotyping needs to be done, thereby saving costs, and (2 markers can be filtered for various quality measures and replacement markers (to minimize gaps can be selected at no additional cost. Panels of carefully selected AIMs have two major advantages over panels of random markers: (1 the map power from sparser panels of AIMs is higher than that of ~10-fold denser panels of random markers, and (2 clusters can be labeled based on information from the parental populations. With current technology, chip-based genome-wide genotyping is less expensive than genotyping ~20,000 random markers. The major advantage of using random markers is the absence of ascertainment effects resulting from the process of selecting markers. The ability to develop marker panels informative for ancestry from

  11. High-resolution gene mapping using admixture linkage disequilibrium

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This note reports simulation study on the rate of decay in linkage dis equilibrium (LD) in mixed populations over multiple discrete generations and explores the usefulness of the LD analysis in high-resolution gene mapping. The results indicate that the smaller the recombination fraction and the fewer generati ons since admixtureevent, the higher power of the approach in gene mapping. The expected estimate of recombination fraction would give an estimate that is slig htly biased upwards, if relevant genes are in tight linkage. The estimated recom bination fraction is usually larger than the true value within 2-5 generations. From generations 10-20, the mean estimates are in good agreement with the true value. The method presented here enables estimation of means and corresponding confidence intervals of the recombination fraction at any number of generations.

  12. Admixture mapping of end stage kidney disease genetic susceptibility using estimated mutual information ancestry informative markers

    Directory of Open Access Journals (Sweden)

    Geiger Dan

    2010-10-01

    Full Text Available Abstract Background The question of a genetic contribution to the higher prevalence and incidence of end stage kidney disease (ESKD among African Americans (AA remained unresolved, until recent findings using admixture mapping pointed to the association of a genomic locus on chromosome 22 with this disease phenotype. In the current study we utilize this example to demonstrate the utility of applying a multi-step admixture mapping approach. Methods A multi-step case only admixture mapping study, consisted of the following steps was designed: 1 Assembly of the sample dataset (ESKD AA; 2 Design of the estimated mutual information ancestry informative markers (n = 2016 screening panel 3; Genotyping the sample set whose size was determined by a power analysis (n = 576 appropriate for the initial screening panel; 4 Inference of local ancestry for each individual and identification of regions with increased AA ancestry using two different ancestry inference statistical approaches; 5 Enrichment of the initial screening panel; 6 Power analysis of the enriched panel 7 Genotyping of additional samples. 8 Re-analysis of the genotyping results to identify a genetic risk locus. Results The initial screening phase yielded a significant peak using the ADMIXMAP ancestry inference program applying case only statistics. Subgroup analysis of 299 ESKD patients with no history of diabetes yielded peaks using both the ANCESTRYMAP and ADMIXMAP ancestry inference programs. The significant peak was found on chromosome 22. Genotyping of additional ancestry informative markers on chromosome 22 that took into account linkage disequilibrium in the ancestral populations, and the addition of samples increased the statistical significance of the finding. Conclusions A multi-step admixture mapping analysis of AA ESKD patients replicated the finding of a candidate risk locus on chromosome 22, contributing to the heightened susceptibility of African Americans to develop non

  13. Rate of decay in admixture linkage disequilibrium and its implication in gene mapping

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Modeling linkage disequilibria (LD) between genes usually observed in admixed natural populations has been shown an effective approach in high-resolution mapping of disease genes in humans. A prerequisite to obtain accurate estimation of recombination fraction between genes at a marker locus and the disease locus using the approach is a reliable prediction of the proportion of the admixture populations. The present study suggested the use of gene frequencies to predict the estimate of the admixture propor-tion based on the observation that the gene frequencies are much more stable quantities than the haplotype frequencies over evolution of the population. In this paper, we advanced the theory and methods by which the decay rate of nonlinear term of LD in admixed population may be used to estimate the recombination fraction between the genes. Theoretical analysis and simulation study indicate that, the larger the difference of gene frequencies between parental populations and the more closely the admixture proportion approaches 0.5, the more important the nonlinear term of the LD in the admixed population, and hence the more informative such admixed populations in the high-resolution gene mapping practice.

  14. Genome-wide scan of 29,141 African Americans finds no evidence of selection since admixture

    OpenAIRE

    Bhatia, Gaurav; Tandon, Arti; Aldrich, Melinda C.; Ambrosone, Christine B.; Amos, Christopher; Bandera, Elisa V.; Berndt, Sonja I.; Bernstein, Leslie; William J Blot; Bock, Cathryn H.; Caporaso, Neil; Casey, Graham; Deming, Sandra L.; Diver, W Ryan; Gapstur, Susan M

    2013-01-01

    We scanned through the genomes of 29,141 African Americans, searching for loci where the average proportion of African ancestry deviates significantly from the genome-wide average. We failed to find any genome-wide significant deviations, and conclude that any selection in African Americans since admixture is sufficiently weak that it falls below the threshold of our power to detect it using a large sample size. These results stand in contrast to the findings of a recent study of selection in...

  15. Admixture mapping of 15,280 African Americans identifies obesity susceptibility loci on chromosomes 5 and X.

    Directory of Open Access Journals (Sweden)

    Ching-Yu Cheng

    2009-05-01

    Full Text Available The prevalence of obesity (body mass index (BMI > or =30 kg/m(2 is higher in African Americans than in European Americans, even after adjustment for socioeconomic factors, suggesting that genetic factors may explain some of the difference. To identify genetic loci influencing BMI, we carried out a pooled analysis of genome-wide admixture mapping scans in 15,280 African Americans from 14 epidemiologic studies. Samples were genotyped at a median of 1,411 ancestry-informative markers. After adjusting for age, sex, and study, BMI was analyzed both as a dichotomized (top 20% versus bottom 20% and a continuous trait. We found that a higher percentage of European ancestry was significantly correlated with lower BMI (rho = -0.042, P = 1.6x10(-7. In the dichotomized analysis, we detected two loci on chromosome X as associated with increased African ancestry: the first at Xq25 (locus-specific LOD = 5.94; genome-wide score = 3.22; case-control Z = -3.94; and the second at Xq13.1 (locus-specific LOD = 2.22; case-control Z = -4.62. Quantitative analysis identified a third locus at 5q13.3 where higher BMI was highly significantly associated with greater European ancestry (locus-specific LOD = 6.27; genome-wide score = 3.46. Further mapping studies with dense sets of markers will be necessary to identify the alleles in these regions of chromosomes X and 5 that may be associated with variation in BMI.

  16. Admixture mapping of ankle-arm index: identification of a candidate locus associated with peripheral arterial disease

    OpenAIRE

    Scherer, Matthew L.; Nalls, Michael A; Pawlikowska, Ludmila; Ziv, Elad; Mitchell, Gary; Huntsman, Scott; Hu, Donglei; Sutton-Tyrrell, Kim; Lakatta, Edward G.; Hsueh, Wen-Chi; Newman, Anne B; Tandon, Arti; Kim, Lauren; Kwok, Pui-Yan; Sung, Andrew

    2009-01-01

    Peripheral arterial disease (PAD) is associated with significant morbidity and mortality, and has a higher prevalence in African Americans than Caucasians. Ankle arm index (AAI) is the ratio of systolic blood pressure in the leg to that in the arm, and, when low, is a marker of PAD. We used an admixture mapping approach to search for genetic loci associated with low AAI. Using data from 1040 African-American participants in the observational, population-based Health, Aging, and Body Compositi...

  17. Admixture mapping of serum vitamin D and parathyroid hormone concentrations in the African American-Diabetes Heart Study.

    Science.gov (United States)

    Palmer, Nicholette D; Divers, Jasmin; Lu, Lingyi; Register, Thomas C; Carr, J Jeffrey; Hicks, Pamela J; Smith, S Carrie; Xu, Jianzhao; Judd, Suzanne E; Irvin, Marguerite R; Gutierrez, Orlando M; Bowden, Donald W; Wagenknecht, Lynne E; Langefeld, Carl D; Freedman, Barry I

    2016-06-01

    Vitamin D and intact parathyroid hormone (iPTH) concentrations differ between individuals of African and European descent and may play a role in observed racial differences in bone mineral density (BMD). These findings suggest that mapping by admixture linkage disequilibrium (MALD) may be informative for identifying genetic variants contributing to these ethnic disparities. Admixture mapping was performed for serum 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, vitamin D-binding protein (VDBP), bioavailable vitamin D, and iPTH concentrations and computed tomography measured thoracic and lumbar vertebral volumetric BMD in 552 unrelated African Americans with type 2 diabetes from the African American-Diabetes Heart Study. Genotyping was performed using a custom Illumina ancestry informative marker (AIM) panel. For each AIM, the probability of inheriting 0, 1, or 2 copies of a European-derived allele was determined. Non-parametric linkage analysis was performed by testing for association between each AIM using these probabilities among phenotypes, accounting for global ancestry, age, and gender. Fine-mapping of MALD peaks was facilitated by genome-wide association study (GWAS) data. VDBP levels were significantly linked in proximity to the protein coding locus (rs7689609, LOD=11.05). Two loci exhibited significant linkage signals for 1,25-dihydroxyvitamin D on 13q21.2 (rs1622710, LOD=3.20) and 12q13.2 (rs11171526, LOD=3.10). iPTH was significantly linked on 9q31.3 (rs7854368, LOD=3.14). Fine-mapping with GWAS data revealed significant known (rs7041 with VDBP, P=1.38×10(-82)) and novel (rs12741813 and rs10863774 with VDBP, P<6.43×10(-5)) loci with plausible biological roles. Admixture mapping in combination with fine-mapping has focused efforts to identify loci contributing to ethnic differences in vitamin D-related traits. PMID:27032714

  18. Admixture analysis of stocked brown trout populations using mapped microsatellite DNA markers: indigenous trout persist in introgressed populations.

    Science.gov (United States)

    Hansen, Michael M; Mensberg, Karen-Lise D

    2009-10-23

    Admixture between wild and captive populations is an increasing concern in conservation biology. Understanding the extent of admixture and the processes involved requires identification of admixed and non-admixed individuals. This can be achieved by statistical methods employing Bayesian clustering, but resolution is low if genetic differentiation is weak. Here, we analyse stocked brown trout populations represented by historical (1943-1956) and contemporary (2000s) samples, where genetic differentiation between wild populations and stocked trout is weak (pairwise F(ST) of 0.047 and 0.053). By analysing a high number of microsatellite DNA markers (50) and making use of linkage map information, we achieve clear identification of admixed and non-admixed trout. Moreover, despite strong population-level admixture by hatchery strain trout in one of the populations (70.8%), non-admixed individuals nevertheless persist (7 out of 53 individuals). These remnants of the indigenous population are characterized by later spawning time than the majority of the admixed individuals. We hypothesize that isolation by time mediated by spawning time differences between wild and hatchery strain trout is a major factor rescuing a part of the indigenous population from introgression. PMID:19515653

  19. Admixture Mapping in Lupus Identifies Multiple Functional Variants within IFIH1 Associated with Apoptosis, Inflammation, and Autoantibody Production

    Science.gov (United States)

    Looger, Loren L.; Han, Shizhong; Kim-Howard, Xana; Glenn, Stuart; Adler, Adam; Kelly, Jennifer A.; Niewold, Timothy B.; Gilkeson, Gary S.; Brown, Elizabeth E.; Alarcón, Graciela S.; Edberg, Jeffrey C.; Petri, Michelle; Ramsey-Goldman, Rosalind; Reveille, John D.; Vilá, Luis M.; Freedman, Barry I.; Tsao, Betty P.; Criswell, Lindsey A.; Jacob, Chaim O.; Moore, Jason H.; Vyse, Timothy J.; Langefeld, Carl L.; Guthridge, Joel M.; Gaffney, Patrick M.; Moser, Kathy L.; Scofield, R. Hal; Alarcón-Riquelme, Marta E.; Williams, Scott M.; Merrill, Joan T.; James, Judith A.; Kaufman, Kenneth M.; Kimberly, Robert P.; Harley, John B.; Nath, Swapan K.

    2013-01-01

    Systemic lupus erythematosus (SLE) is an inflammatory autoimmune disease with a strong genetic component. African-Americans (AA) are at increased risk of SLE, but the genetic basis of this risk is largely unknown. To identify causal variants in SLE loci in AA, we performed admixture mapping followed by fine mapping in AA and European-Americans (EA). Through genome-wide admixture mapping in AA, we identified a strong SLE susceptibility locus at 2q22–24 (LOD = 6.28), and the admixture signal is associated with the European ancestry (ancestry risk ratio ∼1.5). Large-scale genotypic analysis on 19,726 individuals of African and European ancestry revealed three independently associated variants in the IFIH1 gene: an intronic variant, rs13023380 [Pmeta = 5.20×10−14; odds ratio, 95% confidence interval = 0.82 (0.78–0.87)], and two missense variants, rs1990760 (Ala946Thr) [Pmeta = 3.08×10−7; 0.88 (0.84–0.93)] and rs10930046 (Arg460His) [Pdom = 1.16×10−8; 0.70 (0.62–0.79)]. Both missense variants produced dramatic phenotypic changes in apoptosis and inflammation-related gene expression. We experimentally validated function of the intronic SNP by DNA electrophoresis, protein identification, and in vitro protein binding assays. DNA carrying the intronic risk allele rs13023380 showed reduced binding efficiency to a cellular protein complex including nucleolin and lupus autoantigen Ku70/80, and showed reduced transcriptional activity in vivo. Thus, in SLE patients, genetic susceptibility could create a biochemical imbalance that dysregulates nucleolin, Ku70/80, or other nucleic acid regulatory proteins. This could promote antibody hypermutation and auto-antibody generation, further destabilizing the cellular network. Together with molecular modeling, our results establish a distinct role for IFIH1 in apoptosis, inflammation, and autoantibody production, and explain the molecular basis of these three risk alleles for SLE pathogenesis. PMID

  20. Admixture mapping in lupus identifies multiple functional variants within IFIH1 associated with apoptosis, inflammation, and autoantibody production.

    Directory of Open Access Journals (Sweden)

    Julio E Molineros

    Full Text Available Systemic lupus erythematosus (SLE is an inflammatory autoimmune disease with a strong genetic component. African-Americans (AA are at increased risk of SLE, but the genetic basis of this risk is largely unknown. To identify causal variants in SLE loci in AA, we performed admixture mapping followed by fine mapping in AA and European-Americans (EA. Through genome-wide admixture mapping in AA, we identified a strong SLE susceptibility locus at 2q22-24 (LOD=6.28, and the admixture signal is associated with the European ancestry (ancestry risk ratio ~1.5. Large-scale genotypic analysis on 19,726 individuals of African and European ancestry revealed three independently associated variants in the IFIH1 gene: an intronic variant, rs13023380 [P(meta = 5.20×10(-14; odds ratio, 95% confidence interval = 0.82 (0.78-0.87], and two missense variants, rs1990760 (Ala946Thr [P(meta = 3.08×10(-7; 0.88 (0.84-0.93] and rs10930046 (Arg460His [P(dom = 1.16×10(-8; 0.70 (0.62-0.79]. Both missense variants produced dramatic phenotypic changes in apoptosis and inflammation-related gene expression. We experimentally validated function of the intronic SNP by DNA electrophoresis, protein identification, and in vitro protein binding assays. DNA carrying the intronic risk allele rs13023380 showed reduced binding efficiency to a cellular protein complex including nucleolin and lupus autoantigen Ku70/80, and showed reduced transcriptional activity in vivo. Thus, in SLE patients, genetic susceptibility could create a biochemical imbalance that dysregulates nucleolin, Ku70/80, or other nucleic acid regulatory proteins. This could promote antibody hypermutation and auto-antibody generation, further destabilizing the cellular network. Together with molecular modeling, our results establish a distinct role for IFIH1 in apoptosis, inflammation, and autoantibody production, and explain the molecular basis of these three risk alleles for SLE pathogenesis.

  1. Admixture analysis of stocked brown trout populations using mapped microsatellite DNA markers: indigenous trout persist in introgressed populations

    OpenAIRE

    Hansen, Michael M; Mensberg, Karen-Lise D.

    2009-01-01

    Admixture between wild and captive populations is an increasing concern in conservation biology. Understanding the extent of admixture and the processes involved requires identification of admixed and non-admixed individuals. This can be achieved by statistical methods employing Bayesian clustering, but resolution is low if genetic differentiation is weak. Here, we analyse stocked brown trout populations represented by historical (1943–1956) and contemporary (2000s) samples, where genetic dif...

  2. Structural Modeling Using "Scanning and Mapping" Technique

    Science.gov (United States)

    Amos, Courtney L.; Dash, Gerald S.; Shen, J. Y.; Ferguson, Frederick; Noga, Donald F. (Technical Monitor)

    2000-01-01

    Supported by NASA Glenn Center, we are in the process developing a structural damage diagnostic and monitoring system for rocket engines, which consists of five modules: Structural Modeling, Measurement Data Pre-Processor, Structural System Identification, Damage Detection Criterion, and Computer Visualization. The function of the system is to detect damage as it is incurred by the engine structures. The scientific principle to identify damage is to utilize the changes in the vibrational properties between the pre-damaged and post-damaged structures. The vibrational properties of the pre-damaged structure can be obtained based on an analytic computer model of the structure. Thus, as the first stage of the whole research plan, we currently focus on the first module - Structural Modeling. Three computer software packages are selected, and will be integrated for this purpose. They are PhotoModeler-Pro, AutoCAD-R14, and MSC/NASTRAN. AutoCAD is the most popular PC-CAD system currently available in the market. For our purpose, it plays like an interface to generate structural models of any particular engine parts or assembly, which is then passed to MSC/NASTRAN for extracting structural dynamic properties. Although AutoCAD is a powerful structural modeling tool, the complexity of engine components requires a further improvement in structural modeling techniques. We are working on a so-called "scanning and mapping" technique, which is a relatively new technique. The basic idea is to producing a full and accurate 3D structural model by tracing on multiple overlapping photographs taken from different angles. There is no need to input point positions, angles, distances or axes. Photographs can be taken by any types of cameras with different lenses. With the integration of such a modeling technique, the capability of structural modeling will be enhanced. The prototypes of any complex structural components will be produced by PhotoModeler first based on existing similar

  3. Conductivity map from scanning tunneling potentiometry

    Science.gov (United States)

    Zhang, Hao; Li, Xianqi; Chen, Yunmei; Durand, Corentin; Li, An-Ping; Zhang, X.-G.

    2016-08-01

    We present a novel method for extracting two-dimensional (2D) conductivity profiles from large electrochemical potential datasets acquired by scanning tunneling potentiometry of a 2D conductor. The method consists of a data preprocessing procedure to reduce/eliminate noise and a numerical conductivity reconstruction. The preprocessing procedure employs an inverse consistent image registration method to align the forward and backward scans of the same line for each image line followed by a total variation (TV) based image restoration method to obtain a (nearly) noise-free potential from the aligned scans. The preprocessed potential is then used for numerical conductivity reconstruction, based on a TV model solved by accelerated alternating direction method of multiplier. The method is demonstrated on a measurement of the grain boundary of a monolayer graphene, yielding a nearly 10:1 ratio for the grain boundary resistivity over bulk resistivity.

  4. A fast map-making preconditioner for regular scanning patterns

    Energy Technology Data Exchange (ETDEWEB)

    Næss, Sigurd K.; Louis, Thibaut, E-mail: sigurd.naess@astro.ox.ac.uk, E-mail: thibaut.louis@astro.ox.ac.uk [Sub-department of Astrophysics, University of Oxford, Keble Road, Oxford, OX1 3RH (United Kingdom)

    2014-08-01

    High-resolution Maximum Likelihood map-making of the Cosmic Microwave Background is usually performed using Conjugate Gradients with a preconditioner that ignores noise correlations. We here present a new preconditioner that approximates the map noise covariance as circulant, and show that this results in a speedup of up to 400% for a realistic scanning pattern from the Atacama Cosmology Telescope. The improvement is especially large for polarized maps.

  5. A fast map-making preconditioner for regular scanning patterns

    International Nuclear Information System (INIS)

    High-resolution Maximum Likelihood map-making of the Cosmic Microwave Background is usually performed using Conjugate Gradients with a preconditioner that ignores noise correlations. We here present a new preconditioner that approximates the map noise covariance as circulant, and show that this results in a speedup of up to 400% for a realistic scanning pattern from the Atacama Cosmology Telescope. The improvement is especially large for polarized maps

  6. A fast map-making preconditioner for regular scanning patterns

    CERN Document Server

    Næss, Sigurd

    2013-01-01

    High-resolution Maximum Likelihood map-making of the Cosmic Microwave Background is usually performed using Conjugate Gradients with a preconditioner that ignores noise correlations. We here present a new preconditioner that approximates the map noise covariance as circulant, and show that this results in a speedup of up to 400% for a realistic scanning pattern from the Atacama Cosmology Telescope. The improvement is especially large for polarized maps.

  7. Orientation mapping of semicrystalline polymers using scanning electron nanobeam diffraction.

    Science.gov (United States)

    Panova, Ouliana; Chen, X Chelsea; Bustillo, Karen C; Ophus, Colin; Bhatt, Mahesh P; Balsara, Nitash; Minor, Andrew M

    2016-09-01

    We demonstrate a scanning electron nanobeam diffraction technique that can be used for mapping the size and distribution of nanoscale crystalline regions in a polymer blend. In addition, it can map the relative orientation of crystallites and the degree of crystallinity of the material. The model polymer blend is a 50:50w/w mixture of semicrystalline poly(3-hexylthiophene-2,5-diyl) (P3HT) and amorphous polystyrene (PS). The technique uses a scanning electron beam to raster across the sample and acquires a diffraction image at each probe position. Through image alignment and filtering, the diffraction image dataset enables mapping of the crystalline regions within the scanned area and construction of an orientation map. PMID:27323282

  8. Temperature mapping of operating nanoscale devices by scanning probe thermometry

    Science.gov (United States)

    Menges, Fabian; Mensch, Philipp; Schmid, Heinz; Riel, Heike; Stemmer, Andreas; Gotsmann, Bernd

    2016-03-01

    Imaging temperature fields at the nanoscale is a central challenge in various areas of science and technology. Nanoscopic hotspots, such as those observed in integrated circuits or plasmonic nanostructures, can be used to modify the local properties of matter, govern physical processes, activate chemical reactions and trigger biological mechanisms in living organisms. The development of high-resolution thermometry techniques is essential for understanding local thermal non-equilibrium processes during the operation of numerous nanoscale devices. Here we present a technique to map temperature fields using a scanning thermal microscope. Our method permits the elimination of tip-sample contact-related artefacts, a major hurdle that so far has limited the use of scanning probe microscopy for nanoscale thermometry. We map local Peltier effects at the metal-semiconductor contacts to an indium arsenide nanowire and self-heating of a metal interconnect with 7 mK and sub-10 nm spatial temperature resolution.

  9. Laser scanning confocal microscopy for 3D surface mapping

    Czech Academy of Sciences Publication Activity Database

    Lapšanská, Hana; Schovánek, Petr

    Rožnov pod Radhoštěm : TECON Scientific, s.r.o., 2010 - (Vojtěchovský, K.), s. 435-440 ISBN 978-80-254-7361-0. [Scientific and Business Conference SILICON 2010 /12./. Rožnov pod Radhoštěm (CZ), 02.11.2010-05.11.2010] R&D Projects: GA AV ČR KAN301370701 Institutional research plan: CEZ:AV0Z10100522 Keywords : laser scanning * 3D surface mapping Subject RIV: BM - Solid Matter Physics ; Magnetism

  10. Multispectral Airborne Laser Scanning for Automated Map Updating

    Science.gov (United States)

    Matikainen, Leena; Hyyppä, Juha; Litkey, Paula

    2016-06-01

    During the last 20 years, airborne laser scanning (ALS), often combined with multispectral information from aerial images, has shown its high feasibility for automated mapping processes. Recently, the first multispectral airborne laser scanners have been launched, and multispectral information is for the first time directly available for 3D ALS point clouds. This article discusses the potential of this new single-sensor technology in map updating, especially in automated object detection and change detection. For our study, Optech Titan multispectral ALS data over a suburban area in Finland were acquired. Results from a random forests analysis suggest that the multispectral intensity information is useful for land cover classification, also when considering ground surface objects and classes, such as roads. An out-of-bag estimate for classification error was about 3% for separating classes asphalt, gravel, rocky areas and low vegetation from each other. For buildings and trees, it was under 1%. According to feature importance analyses, multispectral features based on several channels were more useful that those based on one channel. Automatic change detection utilizing the new multispectral ALS data, an old digital surface model (DSM) and old building vectors was also demonstrated. Overall, our first analyses suggest that the new data are very promising for further increasing the automation level in mapping. The multispectral ALS technology is independent of external illumination conditions, and intensity images produced from the data do not include shadows. These are significant advantages when the development of automated classification and change detection procedures is considered.

  11. Scanned Hardcopy Maps, map book, Published in 2009, 1:24000 (1in=2000ft) scale, Washington County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Scanned Hardcopy Maps dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Other information as of 2009. It is described as 'map...

  12. Elemental maps of Amoeba proteus by a scanning proton microprobe

    International Nuclear Information System (INIS)

    Elemental maps for P, S, Cl, K, Ca and Zn of individual Amoeba proteus were obtained with the Melbourne scanning proton microprobe. The emphasis was put on the relationship of both distribution and concentration of Zn within the cell and the growth inhibitory effect of higher Zn concentrations in the culture medium. At a concentration of 0.04 mmol ZnCl2. Amoeba growth was inhibited. But at a concentration of 0.0016 mmol, the Amoeba grew as well as a control grown without addition of Zn. We found that in the former (0.04 mmol) Zn concentrated three times more than in the latter (0.0016 mmol), and also that Zn was enriched much more in the nucleus and endoplasm (five to six times) than in other parts of the cell (two times). Future work along these lines may provide insight into the mechanism by which Zn affects the growth of Amoeba proteus and other cells. (orig.)

  13. Low Temperature Concrete Admixture

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    Performing construction processes under the cold weather condition requires construction engineers to plan operations considering low temperature condition. Concrete admixture mostly chemically interact with the constituents of concrete and affect the properties and characteristics of the fresh and hardened concrete and its durability. The purposes of the admixtures include water reduction, high strength, corrosion protection, crack control, finish enhancement, flowability, etc. One of the in...

  14. Scanned Hardcopy Maps, legato data base; public works, Published in 2006, Washoe County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Scanned Hardcopy Maps dataset, was produced all or in part from Hardcopy Maps information as of 2006. It is described as 'legato data base; public works'. Data...

  15. Scanning Transmission X-Ray, Laser Scanning, and Transmission Electron Microscopy Mapping of the Exopolymeric Matrix of Microbial Biofilms

    OpenAIRE

    Lawrence, J R; Swerhone, G. D. W.; Leppard, G. G.; Araki, T; Zhang, X.; West, M. M.; Hitchcock, A. P.

    2003-01-01

    Confocal laser scanning microscopy (CLSM), transmission electron microscopy (TEM), and soft X-ray scanning transmission X-ray microscopy (STXM) were used to map the distribution of macromolecular subcomponents (e.g., polysaccharides, proteins, lipids, and nucleic acids) of biofilm cells and matrix. The biofilms were developed from river water supplemented with methanol, and although they comprised a complex microbial community, the biofilms were dominated by heterotrophic bacteria. TEM provid...

  16. High-Performance Grouting Mortar Based on Mineral Admixtures

    OpenAIRE

    2015-01-01

    A study on high-performance grouting mortar is reported. The common mortar was modified by mineral admixtures such as gypsum, bauxite, and alunite. The effects of mineral admixtures on the fluidity, setting time, expansion, strength, and other properties of mortar were evaluated experimentally. The microstructure of the modified mortar was characterized by X-ray diffraction, scanning electron microscopy, and mercury intrusion porosimetry. Moreover, the expansive performance and strength of th...

  17. Sonar scan matching for simultaneous localization and mapping in confined underwater environments

    OpenAIRE

    Mallios, Angelos

    2014-01-01

    This thesis presents the development of a localization and mapping algorithm for an autonomous underwater vehicle (AUV). It is based on probabilistic scan matching of raw sonar scans within a pose-based simultaneous localization and mapping(SLAM) framework Aquesta tesis presenta el desenvolupament d’un algoritme de localització i mapeig per un vehicle submarí autònom (AUV). L’algoritme es basa en tècniques probabilístiques de scan matching utilitzant scans de sonar dins un sistema de local...

  18. Scanned Hardcopy Maps, Plat of Survey maps filed in the Manitowoc County Real Propery Lister's Office., Published in unknown, Manitowoc County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Scanned Hardcopy Maps dataset, was produced all or in part from Hardcopy Maps information as of unknown. It is described as 'Plat of Survey maps filed in the...

  19. Dating the age of admixture via wavelet transform analysis of genome-wide data.

    Science.gov (United States)

    Pugach, Irina; Matveyev, Rostislav; Wollstein, Andreas; Kayser, Manfred; Stoneking, Mark

    2011-01-01

    We describe a PCA-based genome scan approach to analyze genome-wide admixture structure, and introduce wavelet transform analysis as a method for estimating the time of admixture. We test the wavelet transform method with simulations and apply it to genome-wide SNP data from eight admixed human populations. The wavelet transform method offers better resolution than existing methods for dating admixture, and can be applied to either SNP or sequence data from humans or other species. PMID:21352535

  20. Dating the age of admixture via wavelet transform analysis of genome-wide data

    OpenAIRE

    Pugach, Irina; Matveyev, Rostislav; Wollstein, Andreas; Kayser, Manfred; Stoneking, Mark

    2011-01-01

    textabstractWe describe a PCA-based genome scan approach to analyze genome-wide admixture structure, and introduce wavelet transform analysis as a method for estimating the time of admixture. We test the wavelet transform method with simulations and apply it to genome-wide SNP data from eight admixed human populations. The wavelet transform method offers better resolution than existing methods for dating admixture, and can be applied to either SNP or sequence data from humans or other species.

  1. Automatic Stem Mapping by Merging Several Terrestrial Laser Scans at the Feature and Decision Levels

    Directory of Open Access Journals (Sweden)

    Juha Hyyppä

    2013-01-01

    Full Text Available Detailed up-to-date ground reference data have become increasingly important in quantitative forest inventories. Field reference data are conventionally collected at the sample plot level by means of manual measurements, which are both labor-intensive and time-consuming. In addition, the number of attributes collected from the tree stem is limited. More recently, terrestrial laser scanning (TLS, using both single-scan and multi-scan techniques, has proven to be a promising solution for efficient stem mapping at the plot level. In the single-scan method, the laser scanner is placed at the center of the plot, creating only one scan, and all trees are mapped from the single-scan point cloud. Consequently, the occlusion of stems increases as the range of the scanner increases, depending on the forest’s attributes. In the conventional multi-scan method, several scans are made simultaneously inside and outside of the plot to collect point clouds representing all trees within the plot, and these scans are accurately co-registered by using artificial reference targets manually placed throughout the plot. The additional difficulty of applying the multi-scan method is due to the point-cloud registration of several scans not being fully automated yet. This paper proposes a multi-single-scan (MSS method to map the sample plot. The method does not require artificial reference targets placed on the plot or point-level registration. The MSS method is based on the fully automated processing of each scan independently and on the merging of the stem positions automatically detected from multiple scans to accurately map the sample plot. The proposed MSS method was tested on five dense forest plots. The results show that the MSS method significantly improves the stem-detection accuracy compared with the single-scan approach and achieves a mapping accuracy similar to that achieved with the multi-scan method, without the need for the point-level registration.

  2. Strain Mapping by Scanning Low Energy Electron Microscopy

    Czech Academy of Sciences Publication Activity Database

    Mikmeková, Šárka; Man, O.; Pantělejev, L.; Hovorka, Miloš; Müllerová, Ilona; Frank, Luděk; Kouřil, M.

    Zurich : Trans Tech Publications, 2011 - (Šandera, P.), s. 338-341 ISBN 978-3-03785-006-0. ISSN 1662-9795. [MSMF-6: Materials Structure and Micromechanics of Fracture VI. Brno (CZ), 28.06.2010-30.06.2010] R&D Projects: GA AV ČR IAA100650902; GA MŠk OE08012 Institutional research plan: CEZ:AV0Z20650511 Keywords : scanning low energy electron microscopy (SLEEM) * contrast of crystal orientation * microscopic strain Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  3. Measuring and using admixture to study the genetics of complex diseases

    Directory of Open Access Journals (Sweden)

    Halder Indrani

    2003-11-01

    Full Text Available Abstract Admixture is an important evolutionary force that can and should be used in efforts to apply genomic data and technology to the study of complex disease genetics. Admixture linkage disequilibrium (ALD is created by the process of admixture and, in recently admixed populations, extends for substantial distances (of the order of 10 to 20 cM. The amount of ALD generated depends on the level of admixture, ancestry information content of markers and the admixture dynamics of the population, and thus influences admixture mapping (AM. The authors discuss different models of admixture and how these can have an impact on the success of AM studies. Selection of markers is important, since markers informative for parental population ancestry are required and these are uncommon. Rarely does the process of admixture result in a population that is uniform for individual admixture levels, but instead there is substantial population stratification. This stratification can be understood as variation in individual admixtures and can be both a source of statistical power for ancestry-phenotype correlation studies as well as a confounder in causing false-positives in gene association studies. Methods to detect and control for stratification in case/control and AM studies are reviewed, along with recent studies showing individual ancestry-phenotype correlations. Using skin pigmentation as a model phenotype, implications of AM in complex disease gene mapping studies are discussed. Finally, the article discusses some limitations of this approach that should be considered when designing an effective AM study.

  4. Development of a scanning proton microprobe - computer-control, elemental mapping and applications

    International Nuclear Information System (INIS)

    A scanning proton microprobe set-up has been developed at the Pelletron accelerator in Lund. A magnetic beam scanning system and a computer-control system for beam scanning and data aquisition is described. The computer system consists of a VMEbus front-end computer and a μVax-II host-computer, interfaced by means of a high-speed data link. The VMEbus computer controls data acquisition, beam charge monitoring and beam scanning while the more sophisticated work of elemental mapping and spectrum evaluations is left to the μVax-II. The calibration of the set-up is described as well as several applications. Elemental micro patterns in tree rings and bark has been investigated by means of elemental mapping and quantitative analysis. Large variations of elemental concentrations have been found for several elements within a single tree ring. An external beam set-up has been developed in addition to the proton microprobe set-up. The external beam has been used for the analysis of antique papyrus documents. Using a scanning sample procedure and particle induced X-ray emission (PIXE) analysis, damaged and missing characters of the text could be made visible by means of multivariate statistical data evaluation and elemental mapping. Also aspects of elemental mapping by means of scanning μPIXE analysis are discussed. Spectrum background, target thickness variations and pile-up are shown to influence the structure of elemental maps considerably. In addition, a semi-quantification procedure has been developed. (author)

  5. Dating the age of admixture via wavelet transform analysis of genome-wide data

    NARCIS (Netherlands)

    I. Pugach (Irina); R. Matveyev (Rostislav); A. Wollstein (Andreas); M.H. Kayser (Manfred); M. Stoneking (Mark)

    2011-01-01

    textabstractWe describe a PCA-based genome scan approach to analyze genome-wide admixture structure, and introduce wavelet transform analysis as a method for estimating the time of admixture. We test the wavelet transform method with simulations and apply it to genome-wide SNP data from eight admixe

  6. Geographic patterns of genome admixture in Latin American Mestizos.

    Directory of Open Access Journals (Sweden)

    Sijia Wang

    2008-03-01

    Full Text Available The large and diverse population of Latin America is potentially a powerful resource for elucidating the genetic basis of complex traits through admixture mapping. However, no genome-wide characterization of admixture across Latin America has yet been attempted. Here, we report an analysis of admixture in thirteen Mestizo populations (i.e. in regions of mainly European and Native settlement from seven countries in Latin America based on data for 678 autosomal and 29 X-chromosome microsatellites. We found extensive variation in Native American and European ancestry (and generally low levels of African ancestry among populations and individuals, and evidence that admixture across Latin America has often involved predominantly European men and both Native and African women. An admixture analysis allowing for Native American population subdivision revealed a differentiation of the Native American ancestry amongst Mestizos. This observation is consistent with the genetic structure of pre-Columbian populations and with admixture having involved Natives from the area where the Mestizo examined are located. Our findings agree with available information on the demographic history of Latin America and have a number of implications for the design of association studies in population from the region.

  7. Scanned Hardcopy Maps, Flood Insurance Rate Maps, countywide, Published in 2008, 1:2400 (1in=200ft) scale, Dickinson County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Scanned Hardcopy Maps dataset, published at 1:2400 (1in=200ft) scale, was produced all or in part from Hardcopy Maps information as of 2008. It is described as...

  8. Full-information Maximum Likelihood Estimation of Brand Positioning Maps Using Supermarkt Scanning Data

    NARCIS (Netherlands)

    E. Waarts (Eric); M.A. Carree (Martin); B. Wierenga (Berend)

    1991-01-01

    textabstractThe authors build on the idea put forward by Shugan to infer product maps from scanning data. They demonstrate that the actual estimation procedure used by Shugan has several methodological problems and may yield unstable estimates. They propose an alternative estimation procedure, full-

  9. Mapping metals in Parkinson's and normal brain using rapid-scanning x-ray fluorescence

    Science.gov (United States)

    Popescu, Bogdan F. Gh; George, Martin J.; Bergmann, Uwe; Garachtchenko, Alex V.; Kelly, Michael E.; McCrea, Richard P. E.; Lüning, Katharina; Devon, Richard M.; George, Graham N.; Hanson, Akela D.; Harder, Sheri M.; Chapman, L. Dean; Pickering, Ingrid J.; Nichol, Helen

    2009-02-01

    Rapid-scanning x-ray fluorescence (RS-XRF) is a synchrotron technology that maps multiple metals in tissues by employing unique hardware and software to increase scanning speed. RS-XRF was validated by mapping and quantifying iron, zinc and copper in brain slices from Parkinson's disease (PD) and unaffected subjects. Regions and structures in the brain were readily identified by their metal complement and each metal had a unique distribution. Many zinc-rich brain regions were low in iron and vice versa. The location and amount of iron in brain regions known to be affected in PD agreed with analyses using other methods. Sample preparation is simple and standard formalin-fixed autopsy slices are suitable. RS-XRF can simultaneously and non-destructively map and quantify multiple metals and holds great promise to reveal metal pathologies associated with PD and other neurodegenerative diseases as well as diseases of metal metabolism.

  10. Mapping metals in Parkinson's and normal brain using rapid-scanning x-ray fluorescence

    International Nuclear Information System (INIS)

    Rapid-scanning x-ray fluorescence (RS-XRF) is a synchrotron technology that maps multiple metals in tissues by employing unique hardware and software to increase scanning speed. RS-XRF was validated by mapping and quantifying iron, zinc and copper in brain slices from Parkinson's disease (PD) and unaffected subjects. Regions and structures in the brain were readily identified by their metal complement and each metal had a unique distribution. Many zinc-rich brain regions were low in iron and vice versa. The location and amount of iron in brain regions known to be affected in PD agreed with analyses using other methods. Sample preparation is simple and standard formalin-fixed autopsy slices are suitable. RS-XRF can simultaneously and non-destructively map and quantify multiple metals and holds great promise to reveal metal pathologies associated with PD and other neurodegenerative diseases as well as diseases of metal metabolism.

  11. A Spatial Framework for Understanding Population Structure and Admixture

    Science.gov (United States)

    Bradburd, Gideon S.; Ralph, Peter L.; Coop, Graham M.

    2016-01-01

    Geographic patterns of genetic variation within modern populations, produced by complex histories of migration, can be difficult to infer and visually summarize. A general consequence of geographically limited dispersal is that samples from nearby locations tend to be more closely related than samples from distant locations, and so genetic covariance often recapitulates geographic proximity. We use genome-wide polymorphism data to build “geogenetic maps,” which, when applied to stationary populations, produces a map of the geographic positions of the populations, but with distances distorted to reflect historical rates of gene flow. In the underlying model, allele frequency covariance is a decreasing function of geogenetic distance, and nonlocal gene flow such as admixture can be identified as anomalously strong covariance over long distances. This admixture is explicitly co-estimated and depicted as arrows, from the source of admixture to the recipient, on the geogenetic map. We demonstrate the utility of this method on a circum-Tibetan sampling of the greenish warbler (Phylloscopus trochiloides), in which we find evidence for gene flow between the adjacent, terminal populations of the ring species. We also analyze a global sampling of human populations, for which we largely recover the geography of the sampling, with support for significant histories of admixture in many samples. This new tool for understanding and visualizing patterns of population structure is implemented in a Bayesian framework in the program SpaceMix. PMID:26771578

  12. Note: Electron energy spectroscopy mapping of surface with scanning tunneling microscope

    Science.gov (United States)

    Li, Meng; Xu, Chunkai; Zhang, Panke; Li, Zhean; Chen, Xiangjun

    2016-08-01

    We report a novel scanning probe electron energy spectrometer (SPEES) which combines a double toroidal analyzer with a scanning tunneling microscope to achieve both topography imaging and electron energy spectroscopy mapping of surface in situ. The spatial resolution of spectroscopy mapping is determined to be better than 0.7 ± 0.2 μm at a tip sample distance of 7 μm. Meanwhile, the size of the field emission electron beam spot on the surface is also measured, and is about 3.6 ± 0.8 μm in diameter. This unambiguously demonstrates that the spatial resolution of SPEES technique can be much better than the size of the incident electron beam.

  13. Admixture elements as indicators of fluorite genesis

    International Nuclear Information System (INIS)

    Present book is devoted to comparative analysis of abundance and distribution of admixture elements in fluorite-mineral. The data on composition and content of admixture elements in fluorite was generalized. The hydrothermal deposits were characterized on mineral types.

  14. WIDE-AREA MAPPING OF FOREST WITH NATIONAL AIRBORNE LASER SCANNING AND FIELD INVENTORY DATASETS

    OpenAIRE

    Monnet, J.-M.; C. Ginzler; Clivaz, J.-C.

    2016-01-01

    Airborne laser scanning (ALS) remote sensing data are now available for entire countries such as Switzerland. Methods for the estimation of forest parameters from ALS have been intensively investigated in the past years. However, the implementation of a forest mapping workflow based on available data at a regional level still remains challenging. A case study was implemented in the Canton of Valais (Switzerland). The national ALS dataset and field data of the Swiss National Forest Inventory w...

  15. A scanning drift tube apparatus for spatio-temporal mapping of electron swarms

    OpenAIRE

    Korolov, I.; Vass, M.; Bastykova, N. Kh.; Donko, Z.

    2016-01-01

    A "scanning" drift tube apparatus, capable of mapping of the spatio-temporal evolution of electron swarms, developing between two plane electrodes under the effect of a homogeneous electric field, is presented. The electron swarms are initiated by photoelectron pulses and the temporal distributions of the electron flux are recorded while the electrode gap length (at a fixed electric field strength) is varied. Operation of the system is tested and verified with argon gas, the measured data are...

  16. Analysis of HMPAO SPECT Scans in Head Injury Using Statistical Parametric Mapping

    OpenAIRE

    Stamatakis, E. A.; Wilson, J. T. L.; Wyper, D J

    2000-01-01

    The paper examines the ability of Statistical Parametric Mapping (SPM) to contribute towards the quantitative analysis of HMPAO SPECT images containing lesions. A validation study is described in which SPECT images were created that contained synthetic lesions and were analysed with SPM. The study established a set of guidelines concerning the alignment, smoothing, and statistical analysis of images. These were then applied to analysis of SPECT scans from head injured patients. A demonstratio...

  17. Mapping chemical concentration in binary thin organic films via multi-wavelength scanning absorption microscopy (MWSAM)

    International Nuclear Information System (INIS)

    The composition and thickness of binary thin organic films is determined by measuring the optical absorption at multiple wavelengths across the film surface and performing a component analysis fit to absorption standards for the materials. The multiple laser wavelengths are focused onto the surface using microscope objectives and raster scanned across the film surface using a piezo-electric actuator X–Y stage. All of the wavelengths are scanned simultaneously with a frequency division multiplexing system used to separate the individual wavelength response. The composition values are in good quantitative agreement with measurements obtained by scanning transmission x-ray microscopy (STXM). This new characterization technique extends quantitative compositional mapping of thin films to thickness regimes beyond that accessible by STXM. (paper)

  18. Raman and CT scan mapping of chalcogenide glass diffusion generated gradient index profiles

    Science.gov (United States)

    Lindberg, G. P.; Berg, R. H.; Deegan, J.; Benson, R.; Salvaggio, P. S.; Gross, N.; Weinstein, B. A.; Gibson, D.; Bayya, S.; Sanghera, J.; Nguyen, V.; Kotov, M.

    2016-05-01

    Metrology of a gradient index (GRIN) material is non-trivial, especially in the realm of infrared and large refractive index. Traditional methods rely on index matching fluids which are not available for indexes as high as those found in the chalcogenide glasses (2.4-3.2). By diffusing chalcogenide glasses of similar composition one can blend the properties in a continuous way. In an effort to measure this we will present data from both x-ray computed tomography scans (CT scans) and Raman mapping scans of the diffusion profiles. Proof of concept measurements on undiffused bonded sheets of chalcogenide glasses were presented previously. The profiles measured will be of axially stacked sheets of chalcogenide glasses diffused to create a linear GRIN profile and nested tubes of chalcogenide glasses diffused to create a radial parabolic GRIN profile. We will show that the x-ray absorption in the CT scan and the intensity of select Raman peaks spatially measured through the material are indicators of the concentration of the diffusion ions and correlate to the spatial change in refractive index. We will also present finite element modeling (FEM) results and compare them to post precision glass molded (PGM) elements that have undergone CT and Raman mapping.

  19. Multi-kilohertz Microlaser Altimeter(MMLA)Real-time Scan Footprint Mapping Software

    Science.gov (United States)

    Sanovia, J.

    2003-12-01

    It is expected that this near Real-time Scan Footprint Mapping Software (R-T Scan) display will alert us to any missed areas that we can re-fly to obtain more complete coverage. The value-added custom software is the Visual Basic Data conversion package. This software captures the GPS NEMA string(s) from the 2nd serial port, reads the attitude data form (the shared file of "most recent" attitude data), and performs a geometric projection of 10 (user adjustable) hypothetical laser scan angles to ground based latitude and longitude coordinates. The Lat/Long data are then converted back into the NEMA string format used by Street Atlas. The Multi-kilohertz Micro Laser Altimeter (MMLA) acquires high spatial resolution digital topographic databases and can observe geographical terrains such as hydrological runoff, measure ice sheet thickness, and the changes in lakes and reservoirs. The MMLA is ideal for making topographical (digital) maps of forest settings and cities. (NASA/GSFC 920.3) In order to maximize flight time efficiency and to avoid the potential disastrous situation of missing a target of prime importance, we have developed the MMLA R-T Scan.

  20. Cell culture monitoring by impedance mapping using a multielectrode scanning impedance spectroscopy system (CellMap)

    International Nuclear Information System (INIS)

    We report on the impedance mapping of in vitro cellular morphology by electrical impedance spectroscopy, using microelectrodes. A micro multielectrode system was designed, fabricated, assembled, tested and demonstrated for the monitoring of anchorage-dependent cell behavior and morphology. This system allowed continuous, label-free, quantitative monitoring and visualization of cell adhesion, spreading, proliferation and detachment due to cell cycle processes as well as cell–drug interaction, with spatio-temporal resolution. OvCa429 ovarian cancer cells were monitored in vitro over a period of 70 hours by inoculating the cell suspension directly on the multielectrode device. The phase angle of impedance was observed to develop a distinctive shape as a result of cell attachment and proliferation. The shape of the phase angle curve reverted back to the pre-attachment shape upon detachment of cells from the substrate, caused by the addition of trypsin to the cell culture medium. The impedance data of the cell culture were then successfully modeled as a multi-parametric equivalent circuit. The model incorporated both interfacial and cell-layer impedance parameters. Upon addition of trypsin, the cell-layer parameters showed a marked decline and were eventually eliminated from the multi-parametric model, confirming the correlation of the model to the electrode–cell–electrolyte system. These experiments demonstrate the applicability of the impedance mapping technique in visualizing and quantifying physiological changes in the cell layer due to cellular processes as well as the effect of external chemical stimulus on cells (cell–drug interaction)

  1. Area-Based Mapping of Defoliation of Scots Pine Stands Using Airborne Scanning LiDAR

    Directory of Open Access Journals (Sweden)

    Hannu Hyyppä

    2013-03-01

    Full Text Available The mapping of changes in the distribution of insect-caused forest damage remains an important forest monitoring application and challenge. Efficient and accurate methods are required for mapping and monitoring changes in insect defoliation to inform forest management and reporting activities. In this research, we develop and evaluate a LiDAR-driven (Light Detection And Ranging approach for mapping defoliation caused by the Common pine sawfly (Diprion pini L.. Our method requires plot-level training data and airborne scanning LiDAR data. The approach is predicated on a forest canopy mask created by detecting forest canopy cover using LiDAR. The LiDAR returns that are reflected from the canopy (that is, returns > half of maximum plot tree height are used in the prediction of the defoliation. Predictions of defoliation are made at plot-level, which enables a direct integration of the method to operational forest management planning while also providing additional value-added from inventory-focused LiDAR datasets. In addition to the method development, we evaluated the prediction accuracy and investigated the required pulse density for operational LiDAR-based mapping of defoliation. Our method proved to be suitable for the mapping of defoliated stands, resulting in an overall mapping accuracy of 84.3% and a Cohen’s kappa coefficient of 0.68.

  2. Shrinkage Reducing Admixture for Concrete

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    Concrete shrinkage cracking is a common problem in all types of concrete structures, especially for structures and environments where the cracks are prevalent and the repercussions are most severe. A liquid shrinkage reducing admixture for concrete, developed by GRACE Construction Products and ARCO Chemical Company, that reduces significantly the shrinkage during concrete drying and potentially reduces overall cracking over time.

  3. A scanning drift tube apparatus for spatio-temporal mapping of electron swarms

    CERN Document Server

    Korolov, I; Bastykova, N Kh; Donko, Z

    2016-01-01

    A "scanning" drift tube apparatus, capable of mapping of the spatio-temporal evolution of electron swarms, developing between two plane electrodes under the effect of a homogeneous electric field, is presented. The electron swarms are initiated by photoelectron pulses and the temporal distributions of the electron flux are recorded while the electrode gap length (at a fixed electric field strength) is varied. Operation of the system is tested and verified with argon gas, the measured data are used for the evaluation of the electron bulk drift velocity. The experimental results for the space-time maps of the electron swarms - presented here for the first time - also allow clear observation of deviations from hydrodynamic transport. The swarm maps are also reproduced by particle simulations.

  4. A semi-automatic multiple view texture mapping for the surface model extracted by laser scanning

    Science.gov (United States)

    Zhang, Zhichao; Huang, Xianfeng; Zhang, Fan; Chang, Yongmin; Li, Deren

    2008-12-01

    Laser scanning is an effective way to acquire geometry data of the cultural heritage with complex architecture. After generating the 3D model of the object, it's difficult to do the exactly texture mapping for the real object. we take effort to create seamless texture maps for a virtual heritage of arbitrary topology. Texture detail is acquired directly from the real object in a light condition as uniform as we can make. After preprocessing, images are then registered on the 3D mesh by a semi-automatic way. Then we divide the mesh into mesh patches overlapped with each other according to the valid texture area of each image. An optimal correspondence between mesh patches and sections of the acquired images is built. Then, a smoothing approach is proposed to erase the seam between different images that map on adjacent mesh patches, based on texture blending. The obtained result with a Buddha of Dunhuang Mogao Grottoes is presented and discussed.

  5. Scanned Hardcopy Maps, Prince George's County Scanned ADC Map Pages Mosaic from GIS Intergrated Solutions, Published in 2010, 1:12000 (1in=1000ft) scale, Prince George's County Office of Information Technology and Communications.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Scanned Hardcopy Maps dataset, published at 1:12000 (1in=1000ft) scale, was produced all or in part from Orthoimagery information as of 2010. It is described...

  6. Scanned Hardcopy Maps, Prince George's County Scanned ADC Index Map from GIS Intergrated Solutions, Published in 2010, 1:100000 (1in=8333ft) scale, Prince George's County Office of Information Technology and Communications.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Scanned Hardcopy Maps dataset, published at 1:100000 (1in=8333ft) scale, was produced all or in part from Orthoimagery information as of 2010. It is described...

  7. Multidimensional Laser Scanning System for Underwater Mapping of Small Structures and Bottom Topography

    Science.gov (United States)

    Fuchs, E.

    2005-05-01

    A multidimensional laser scanning imaging system is under development to investigate new concepts in underwater imaging. The system is a modification of the 3D Laser Imaging & Tracking Electro-optical System (3D LITES; HBOI, patent # 5,418,608) that was developed for 3D mapping applications in biological oceanography. The new 3D-FLITES ("F" stands for added Fluorescence capability) captures both spatial and spectral data and offers extended operation capabilities. The system can capture the range to each pixel in the sensor's field of view, the relative reflectance of each pixel (similar to "conventional" images) and five channels of fluorescence emission in the scene, captured sequentially. Multidimensional data sets can be instrumental in bottom topography mapping and object identification. The 3D FLITES has the unique capability to operate in user-selectable line or raster scanning modes if mounted on a moving platform. In raster mode two perpendicular mirrors are driven, allowing the operator to capture single frames (capturing either reflectance or fluorescence data) or a stream of images in fast rate (16 frames per second). With this operational flexibility the operator can combine a "fly over" scanning mode with "look ahead", "look sideways" and "zoom" modes. The current system is limited in range and resolution; nevertheless it can serve as a test-bed to evaluate operational parameters, data acquisition and signal processing protocols that could lead to a smaller, more efficient system in the future.

  8. Geomorphometric analysis of cave ceiling channels mapped with 3-D terrestrial laser scanning

    Science.gov (United States)

    Gallay, Michal; Hochmuth, Zdenko; Kaňuk, Ján; Hofierka, Jaroslav

    2016-05-01

    The change of hydrological conditions during the evolution of caves in carbonate rocks often results in a complex subterranean geomorphology, which comprises specific landforms such as ceiling channels, anastomosing half tubes, or speleothems organized vertically in different levels. Studying such complex environments traditionally requires tedious mapping; however, this is being replaced with terrestrial laser scanning technology. Laser scanning overcomes the problem of reaching high ceilings, providing new options to map underground landscapes with unprecedented level of detail and accuracy. The acquired point cloud can be handled conveniently with dedicated software, but applying traditional geomorphometry to analyse the cave surface is limited. This is because geomorphometry has been focused on parameterization and analysis of surficial terrain. The theoretical and methodological concept has been based on two-dimensional (2-D) scalar fields, which are sufficient for most cases of the surficial terrain. The terrain surface is modelled with a bivariate function of altitude (elevation) and represented by a raster digital elevation model. However, the cave is a 3-D entity; therefore, a different approach is required for geomorphometric analysis. In this paper, we demonstrate the benefits of high-resolution cave mapping and 3-D modelling to better understand the palaeohydrography of the Domica cave in Slovakia. This methodological approach adopted traditional geomorphometric methods in a unique manner and also new methods used in 3-D computer graphics, which can be applied to study other 3-D geomorphological forms.

  9. Scan matching using line segment relationships for map-based localization of mobile robot

    Institute of Scientific and Technical Information of China (English)

    GE Kun-feng; CHEN Wei-dong; WANG Jing-chuan; RAN Yu-yao

    2008-01-01

    A new scan matching method for mobile robot localization is presented, which takes line segment as the feature and matches the real scans in the given reference map by relationships of the directional-defined line segments. The alignment was done by hierarchically identifying the multiple relationships and the result was re-corded in a correspondence matrix, where the best match is defined and selected for localization. It is indicated that the searching algorithm of the best match can find the ambiguities and get rid of them. This method with less computational cost works well in occluded environment, and can correct the error in pose estimation without the need for the estimation itself. The efficiency, accuracy and robustness of this method were verified by exper-iments of localization in an occluded environment and a long-distance indoor navigation.

  10. Mapping of Si/SiC p-n heterojunctions using scanning internal photoemission microscopy

    Science.gov (United States)

    Shingo, Masato; Liang, Jianbo; Shigekawa, Naoteru; Arai, Manabu; Shiojima, Kenji

    2016-04-01

    We demonstrated the two-dimensional characterization of p+-Si/n--SiC heterointerfaces by scanning internal photoemission microscopy (SIPM). In internal photoemission spectra, a linear relationship was found between the square root of photoyield (Y) and photon energy, and the threshold energy (qV th) was reasonably obtained to be 1.34 eV. From the SIPM results, Y and qV th maps were successfully obtained, and nanometer-deep gaps in the junction were sensitively visualized as a pattern. These results suggest that this method is a powerful tool for investigating the inhomogeneity of heterojunctions as well as their carrier transport properties.

  11. Possibilities of a Personal Laser Scanning System for Forest Mapping and Ecosystem Services

    OpenAIRE

    Xinlian Liang; Antero Kukko; Harri Kaartinen; Juha Hyyppä; Xiaowei Yu; Anttoni Jaakkola; Yunsheng Wang

    2014-01-01

    A professional-quality, personal laser scanning (PLS) system for collecting tree attributes was demonstrated in this paper. The applied system, which is wearable by human operators, consists of a multi-constellation navigation system and an ultra-high-speed phase-shift laser scanner mounted on a rigid baseplate and consisting of a single sensor block. A multipass-corridor-mapping method was developed to process PLS data and a 2,000 m2 forest plot was utilized in the test. The tree stem detec...

  12. [Mapping stakeholders' preferences in prioritization criteria for horizon scanning in healthcare technologies].

    Science.gov (United States)

    Nascimento, Aline do; Vidal, Avila Teixeira; Almeida, Rosimary Terezinha de

    2016-08-01

    Filtration and prioritization are two basics steps in horizon scanning systems. This article aimed to map stakeholders' preferences in the Brazilian Unified National Health System (SUS) regarding filtration and prioritization criteria. Two filtration criteria (time horizon and innovation) and eight prioritization criteria (relevance to epidemiology, health policies, and clinical practice; potential impact on SUS budget, healthcare providers' costs, and mortality; safety; and legal, ethical, and social aspects) were selected. Multiple correspondence analysis was used to map stakeholders' preferences within and between groups. Two groups were more homogeneous and determinant for selection of prioritization criteria. Stakeholders' professional experience had more influence than institutional affiliations. The approach showed transparent criteria selection and analysis of stakeholders' individual preferences. PMID:27487444

  13. Possibilities of a personal laser scanning system for forest mapping and ecosystem services.

    Science.gov (United States)

    Liang, Xinlian; Kukko, Antero; Kaartinen, Harri; Hyyppä, Juha; Yu, Xiaowei; Jaakkola, Anttoni; Wang, Yunsheng

    2013-01-01

    A professional-quality, personal laser scanning (PLS) system for collecting tree attributes was demonstrated in this paper. The applied system, which is wearable by human operators, consists of a multi-constellation navigation system and an ultra-high-speed phase-shift laser scanner mounted on a rigid baseplate and consisting of a single sensor block. A multipass-corridor-mapping method was developed to process PLS data and a 2,000 m2 forest plot was utilized in the test. The tree stem detection accuracy was 82.6%; the root mean square error (RMSE) of the estimates of tree diameter at breast height (DBH) was 5.06 cm; the RMSE of the estimates of tree location was 0.38 m. The relative RMSE of the DBH estimates was 14.63%. The results showed, for the first time, the potential of the PLS system in mapping large forest plots. Further research on mapping accuracy in various forest conditions, data correction methods and multi-sensoral positioning techniques is needed. The utilization of this system in different applications, such as harvester operations, should also be explored. In addition to collecting tree-level and plot-level data for forest inventory, other possible applications of PLS for forest ecosystem services include mapping of canopy gaps, measuring leaf area index of large areas, documenting and visualizing forest routes feasible for recreation, hiking and berry and mushroom picking. PMID:24434879

  14. Possibilities of a Personal Laser Scanning System for Forest Mapping and Ecosystem Services

    Directory of Open Access Journals (Sweden)

    Xinlian Liang

    2014-01-01

    Full Text Available A professional-quality, personal laser scanning (PLS system for collecting tree attributes was demonstrated in this paper. The applied system, which is wearable by human operators, consists of a multi-constellation navigation system and an ultra-high-speed phase-shift laser scanner mounted on a rigid baseplate and consisting of a single sensor block. A multipass-corridor-mapping method was developed to process PLS data and a 2,000 m2 forest plot was utilized in the test. The tree stem detection accuracy was 82.6%; the root mean square error (RMSE of the estimates of tree diameter at breast height (DBH was 5.06 cm; the RMSE of the estimates of tree location was 0.38 m. The relative RMSE of the DBH estimates was 14.63%. The results showed, for the first time, the potential of the PLS system in mapping large forest plots. Further research on mapping accuracy in various forest conditions, data correction methods and multi-sensoral positioning techniques is needed. The utilization of this system in different applications, such as harvester operations, should also be explored. In addition to collecting tree-level and plot-level data for forest inventory, other possible applications of PLS for forest ecosystem services include mapping of canopy gaps, measuring leaf area index of large areas, documenting and visualizing forest routes feasible for recreation, hiking and berry and mushroom picking.

  15. Ancient Admixture in Human History

    Science.gov (United States)

    Patterson, Nick; Moorjani, Priya; Luo, Yontao; Mallick, Swapan; Rohland, Nadin; Zhan, Yiping; Genschoreck, Teri; Webster, Teresa; Reich, David

    2012-01-01

    Population mixture is an important process in biology. We present a suite of methods for learning about population mixtures, implemented in a software package called ADMIXTOOLS, that support formal tests for whether mixture occurred and make it possible to infer proportions and dates of mixture. We also describe the development of a new single nucleotide polymorphism (SNP) array consisting of 629,433 sites with clearly documented ascertainment that was specifically designed for population genetic analyses and that we genotyped in 934 individuals from 53 diverse populations. To illustrate the methods, we give a number of examples that provide new insights about the history of human admixture. The most striking finding is a clear signal of admixture into northern Europe, with one ancestral population related to present-day Basques and Sardinians and the other related to present-day populations of northeast Asia and the Americas. This likely reflects a history of admixture between Neolithic migrants and the indigenous Mesolithic population of Europe, consistent with recent analyses of ancient bones from Sweden and the sequencing of the genome of the Tyrolean “Iceman.” PMID:22960212

  16. LIDAR AND INS FUSION IN PERIODS OF GPS OUTAGES FOR MOBILE LASER SCANNING MAPPING SYSTEMS

    Directory of Open Access Journals (Sweden)

    I. Klein

    2012-09-01

    Full Text Available Mobile laser scanning systems are becoming an increasingly popular means to obtain 3D coverage on a large scale. To perform the mapping, the exact position of the vehicle must be known throughout the trajectory. Exact position is achieved via integration of Global Positioning Systems (GPS and Inertial Navigation Systems (INS. Yet, in urban environments, cases of complete or even partial GPS outages may occur leaving the navigation solution to rely only on the INS. The INS navigation solution degrades with time as the Inertial Measurement Unit (IMU measurements contains noise, which permeates into the navigation equations. Degradation of the position determination leads to loss of data in such segments. To circumvent such drift and its effects, we propose fusing INS with lidar data by using building edges. This detection of edges is then translated into position data, which is used as an aiding to the INS. It thereby enables the determination of the vehicle position with a satisfactory level accuracy, sufficient to perform the laser-scanning based mapping in those outage periods.

  17. Calculation of laser pulse distribution maps for corneal reshaping with a scanning beam

    Science.gov (United States)

    Manns, Fabrice; Shen, Jin-Hui; Soederberg, Per G.; Matsui, Takaaki; Parel, Jean-Marie A.

    1995-05-01

    A method for calculating pulse distribution maps for scanning laser corneal surgery is presented. The accuracy, the smoothness of the corneal shape, and the duration of surgery were evaluated for corrections of myopia by using computer simulations. The accuracy and the number of pulses were computed as a function of the beam diameter, the diameter of the treatment zone, and the amount of attempted flattening. The ablation is smooth when the spot overlap is 80% or more. The accuracy does not depend on the beam diameter or on the diameter of the ablation zone when the ablation zone is larger than 5 mm. With an overlap of 80% and an ablation zone larger than 5 mm, the error is 5% of the attempted flattening, and 610 pulses are needed per Diopter of correction with a beam diameter of 1 mm. Pulse maps for the correction of astigmatism were computed and evaluated. The simulations show that with 60% overlap, a beam diameter of 1 mm, and a 5 mm treatment zone, 6 D of astigmatism can be corrected with an accuracy better than 1.8 D. This study shows that smooth and accurate ablations can be produced with a scanning spot.

  18. Mapping surgical fields by moving a laser-scanning multimodal scope attached to a robot arm

    Science.gov (United States)

    Gong, Yuanzheng; Soper, Tomothy D.; Hou, Vivian W.; Hu, Danying; Hannaford, Blake; Seibel, Eric J.

    2014-03-01

    Endoscopic visualization in brain tumor removal is challenging because tumor tissue is often visually indistinguishable from healthy tissue. Fluorescence imaging can improve tumor delineation, though this impairs reflectance-based visualization of gross anatomical features. To accurately navigate and resect tumors, we created an ultrathin/flexible, scanning fiber endoscope (SFE) that acquires reflectance and fluorescence wide-field images at high-resolution. Furthermore, our miniature imaging system is affixed to a robotic arm providing programmable motion of SFE, from which we generate multimodal surface maps of the surgical field. To test this system, synthetic phantoms of debulked tumor from brain are fabricated having spots of fluorescence representing residual tumor. Three-dimension (3D) surface maps of this surgical field are produced by moving the SFE over the phantom during concurrent reflectance and fluorescence imaging (30Hz video). SIFT-based feature matching between reflectance images is implemented to select a subset of key frames, which are reconstructed in 3D by bundle adjustment. The resultant reconstruction yields a multimodal 3D map of the tumor region that can improve visualization and robotic path planning. Efficiency of creating these maps is important as they are generated multiple times during tumor margin clean-up. By using pre-programmed vector motions of the robot arm holding the SFE, the computer vision algorithms are optimized for efficiency by reducing search times. Preliminary results indicate that the time for creating these 3D multimodal maps of the surgical field can be reduced to one third by using known trajectories of the surgical robot moving the image-guided tool.

  19. Recent admixture in an Indian population of African ancestry.

    Science.gov (United States)

    Narang, Ankita; Jha, Pankaj; Rawat, Vimal; Mukhopadhyay, Arijit; Mukhopadhayay, Arijit; Dash, Debasis; Basu, Analabha; Mukerji, Mitali

    2011-07-15

    Identification and study of genetic variation in recently admixed populations not only provides insight into historical population events but also is a powerful approach for mapping disease loci. We studied a population (OG-W-IP) that is of African-Indian origin and has resided in the western part of India for 500 years; members of this population are believed to be descendants of the Bantu-speaking population of Africa. We have carried out this study by using a set of 18,534 autosomal markers common between Indian, CEPH-HGDP, and HapMap populations. Principal-components analysis clearly revealed that the African-Indian population derives its ancestry from Bantu-speaking west-African as well as Indo-European-speaking north and northwest Indian population(s). STRUCTURE and ADMIXTURE analyses show that, overall, the OG-W-IPs derive 58.7% of their genomic ancestry from their African past and have very little inter-individual ancestry variation (8.4%). The extent of linkage disequilibrium also reveals that the admixture event has been recent. Functional annotation of genes encompassing the ancestry-informative markers that are closer in allele frequency to the Indian ancestral population revealed significant enrichment of biological processes, such as ion-channel activity, and cadherins. We briefly examine the implications of determining the genetic diversity of this population, which could provide opportunities for studies involving admixture mapping. PMID:21737057

  20. Towards Automatic Single-Sensor Mapping by Multispectral Airborne Laser Scanning

    Science.gov (United States)

    Ahokas, E.; Hyyppä, J.; Yu, X.; Liang, X.; Matikainen, L.; Karila, K.; Litkey, P.; Kukko, A.; Jaakkola, A.; Kaartinen, H.; Holopainen, M.; Vastaranta, M.

    2016-06-01

    This paper describes the possibilities of the Optech Titan multispectral airborne laser scanner in the fields of mapping and forestry. Investigation was targeted to six land cover classes. Multispectral laser scanner data can be used to distinguish land cover classes of the ground surface, including the roads and separate road surface classes. For forest inventory using point cloud metrics and intensity features combined, total accuracy of 93.5% was achieved for classification of three main boreal tree species (pine, spruce and birch).When using intensity features - without point height metrics - a classification accuracy of 91% was achieved for these three tree species. It was also shown that deciduous trees can be further classified into more species. We propose that intensity-related features and waveform-type features are combined with point height metrics for forest attribute derivation in area-based prediction, which is an operatively applied forest inventory process in Scandinavia. It is expected that multispectral airborne laser scanning can provide highly valuable data for city and forest mapping and is a highly relevant data asset for national and local mapping agencies in the near future.

  1. Digital elevation model production from scanned topographic contour maps via thin plate spline interpolation

    International Nuclear Information System (INIS)

    GIS (Geographical Information System) is one of the most striking innovation for mapping applications supplied by the developing computer and software technology to users. GIS is a very effective tool which can show visually combination of the geographical and non-geographical data by recording these to allow interpretations and analysis. DEM (Digital Elevation Model) is an inalienable component of the GIS. The existing TM (Topographic Map) can be used as the main data source for generating DEM by amanual digitizing or vectorization process for the contours polylines. The aim of this study is to examine the DEM accuracies, which were obtained by TMs, as depending on the number of sampling points and grid size. For these purposes, the contours of the several 1/1000 scaled scanned topographical maps were vectorized. The different DEMs of relevant area have been created by using several datasets with different numbers of sampling points. We focused on the DEM creation from contour lines using gridding with RBF (Radial Basis Function) interpolation techniques, namely TPS as the surface fitting model. The solution algorithm and a short review of the mathematical model of TPS (Thin Plate Spline) interpolation techniques are given. In the test study, results of the application and the obtained accuracies are drawn and discussed. The initial object of this research is to discuss the requirement of DEM in GIS, urban planning, surveying engineering and the other applications with high accuracy (a few deci meters). (author)

  2. The Complex Admixture History and Recent Southern Origins of Siberian Populations.

    Science.gov (United States)

    Pugach, Irina; Matveev, Rostislav; Spitsyn, Viktor; Makarov, Sergey; Novgorodov, Innokentiy; Osakovsky, Vladimir; Stoneking, Mark; Pakendorf, Brigitte

    2016-07-01

    Although Siberia was inhabited by modern humans at an early stage, there is still debate over whether it remained habitable during the extreme cold of the Last Glacial Maximum or whether it was subsequently repopulated by peoples with recent shared ancestry. Previous studies of the genetic history of Siberian populations were hampered by the extensive admixture that appears to have taken place among these populations, because commonly used methods assume a tree-like population history and at most single admixture events. Here we analyze geogenetic maps and use other approaches to distinguish the effects of shared ancestry from prehistoric migrations and contact, and develop a new method based on the covariance of ancestry components, to investigate the potentially complex admixture history. We furthermore adapt a previously devised method of admixture dating for use with multiple events of gene flow, and apply these methods to whole-genome genotype data from over 500 individuals belonging to 20 different Siberian ethnolinguistic groups. The results of these analyses indicate that there have been multiple layers of admixture detectable in most of the Siberian populations, with considerable differences in the admixture histories of individual populations. Furthermore, most of the populations of Siberia included here, even those settled far to the north, appear to have a southern origin, with the northward expansions of different populations possibly being driven partly by the advent of pastoralism, especially reindeer domestication. These newly developed methods to analyze multiple admixture events should aid in the investigation of similarly complex population histories elsewhere. PMID:26993256

  3. Combined effect of expansive and shrinkage reducing admixtures to obtain stable and durable mortars

    International Nuclear Information System (INIS)

    In order to improve the dimensional stability of cement based mortars, the effects produced on cement hydration of a shrinkage reducer (propyleneglycol ether based-SRA) and an expansive admixture (calcium oxide based-EXP) were investigated. Mortar samples (prepared without admixtures or with SRA or EXP or SRA and EXP) were compared through compressive strength measurements, water evaporation, restrained shrinkage and restrained expansion measurements. Setting time and free expansion were also detected on cement paste specimens. A synergistic effect on the shrinkage reduction was observed when the shrinkage reducing admixture and the expansive agent were used together. In order to clarify this phenomenon, the hydration of cement pastes containing these kinds of admixtures was followed by ESEM-FEG (environmental scanning electron microscopy-field emission gun), TG (thermogravimetry), specific surface area measurements (by BET-Brunauer-Emmet-Teller-method) and XRDS (X-ray diffraction spectroscopy)

  4. Using Mobile Laser Scanning Data for Features Extraction of High Accuracy Driving Maps

    Science.gov (United States)

    Yang, Bisheng; Liu, Yuan; Liang, Fuxun; Dong, Zhen

    2016-06-01

    High Accuracy Driving Maps (HADMs) are the core component of Intelligent Drive Assistant Systems (IDAS), which can effectively reduce the traffic accidents due to human error and provide more comfortable driving experiences. Vehicle-based mobile laser scanning (MLS) systems provide an efficient solution to rapidly capture three-dimensional (3D) point clouds of road environments with high flexibility and precision. This paper proposes a novel method to extract road features (e.g., road surfaces, road boundaries, road markings, buildings, guardrails, street lamps, traffic signs, roadside-trees, power lines, vehicles and so on) for HADMs in highway environment. Quantitative evaluations show that the proposed algorithm attains an average precision and recall in terms of 90.6% and 91.2% in extracting road features. Results demonstrate the efficiencies and feasibilities of the proposed method for extraction of road features for HADMs.

  5. Non-Uniform Dose Mapping Controlled by Modulated Vertical and Horizontal Scans

    International Nuclear Information System (INIS)

    Since geometries of semi-conductor devices continue to shrink, the requirement for each process becomes severer to keep uniformity of electrical parameters of the semi-conductor devices. A larger wafer also causes larger variations. Thus it has been strongly required for ion implantation process to compensate for the variations from other processes because of its good dose controllability. A newly developed mapping of intentional non-uniform dosage system, which is named 'MIND system', is implemented in SEN's single-wafer-type implanters. The MIND system controls both horizontal and vertical scan speed simultaneously. Intentional two-dimensional non-uniform profiles of sheet resistance, such as concentric and eccentric profiles, are obtained only by single-step ion implantation.

  6. Scanning electrochemical mapping of spatially localized electrochemical reactions induced by surface potential gradients.

    Science.gov (United States)

    Jayaraman, Shrisudersan; May, Erin L; Hillier, Andrew C

    2006-12-01

    The influence of a surface potential gradient on the location and extent of electrochemical reactions was examined using a scanning electrochemical microscope. A linear potential gradient was imposed on the surface of a platinum-coated indium tin oxide electrode by applying two different potential values at the edges of the electrode. The applied potentials were used to control the location and extent of several electrochemical reactions, including the oxidation of Ru(NH3)6(2+), the oxidation of H2, and the oxidation of H2 in the presence of adsorbed CO. Scanning electrochemical mapping of these reactions was achieved by probing the feedback current associated with the oxidation products. The oxidation of Ru(NH3)6(2+) occurred at locations where the applied potential was positive of the formal potential of the Ru(NH3)6(2+/3+) redox couple. The position of this reaction on the surface could be spatially translated by manipulating the terminal potentials. The rate of hydrogen oxidation on the platinum-coated electrode varied spatially in the presence of a potential gradient and correlated with the nature of the electrode surface. High oxidation rates occurred at low potentials, with decreasing rates observed as the potential increased to values where platinum oxides formed. The extent of oxide formation versus position was confirmed with in-situ ellipsometry mapping. In the presence of adsorbed carbon monoxide, a potential gradient created a localized region of high activity for hydrogen oxidation at potentials between where carbon monoxide was adsorbed and platinum oxides formed. The position of this localized region of activity could be readily translated along the surface by changing the terminal potential values. The ability to manipulate electrochemical reactions spatially on a surface has potential application in microscale analytical devices as well as in the discovery and analysis of electrocatalytic systems. PMID:17128999

  7. Volumetric evolution of Surtsey, Iceland, from topographic maps and scanning airborne laser altimetry

    Science.gov (United States)

    Garvin, J.B.; Williams, R.S.; Frawley, J.J.; Krabill, W.B.

    2000-01-01

    The volumetric evolution of Surtsey has been estimated on the basis of digital elevation models derived from NASA scanning airborne laser altimeter surveys (20 July 1998), as well as digitized 1:5,000-scale topographic maps produced by the National Land Survey of Iceland and by Norrman. Subaerial volumes have been computed from co-registered digital elevation models (DEM's) from 6 July 1968, 11 July 1975, 16 July 1993, and 20 July 1998 (scanning airborne laser altimetry), as well as true surface area (above mean sea level). Our analysis suggests that the subaerial volume of Surtsey has been reduced from nearly 0.100 km3 on 6 July 1968 to 0.075 km3 on 20 July 1998. Linear regression analysis of the temporal evolution of Surtsey's subaerial volume indicates that most of its subaerial surface will be at or below mean sea-level by approximately 2100. This assumes a conservative estimate of continuation of the current pace of marine erosion and mass-wasting on the island, including the indurated core of the conduits of the Surtur I and Surtur II eruptive vents. If the conduits are relatively resistant to marine erosion they will become sea stacks after the rest of the island has become a submarine shoal, and some portions of the island could survive for centuries. The 20 July 1998 scanning laser altimeter surveys further indicate rapid enlargement of erosional canyons in the northeastern portion of the partial tephra ring associated with Surtur I. Continued airborne and eventually spaceborne topographic surveys of Surtsey are planned to refine the inter-annual change of its subaerial volume.

  8. Internal residual strain mapping in carburized chrome molybdenum steel after quenching by neutron strain scanning

    International Nuclear Information System (INIS)

    A hollow circular cylinder specimen with an annular U-notch of chrome molybdenum steel with 0.20 mass% C (SCM420) was carburized in carrier gas and quenched in oil bath. In order to determine the case depth, the specimen was cut off and carbon content and Vickers hardness gradients were measured experimentally near the carburized surface. The residual strain mapping in the interior of carburized cylinder was conducted nondestructively by neutron strain scanning. In this study, the neutron diffraction from Fe-211 plane was used for strain scanning. The neutron wavelength was tuned to 0.1654nm so that diffraction angle became about 90deg. Radial, hoop and axial residual strains were measured by scanning diffracting volume along the axial direction of cylinder specimen. Each residual strain was calculated from lattice spacing change. Unstressed lattice spacing was determined experimentally using reference coupon specimens that were cut from the interior of same carburized cylinder. As a result, the diffraction peak width at half height, FWHM, near the carburized surface was about 3.7 times wider than that of coupon specimens. On the other hand, the most peak widths in the interior equaled to that of coupon specimens. Peak width broadened slightly as the diffracting volume approached the carburized case layer. From the center to the quarter of cylinder specimen, the hoop and axial strains were tensile, and the radial one was compressive in the interior. From the quarter to the edge of the cylinder specimen, the hoop tensile strain increased, radial and axial strains changed to tensile and compressive, respectively. Therefore, the interior of the cylinder specimen was found to be deformed elastically to balance the existence of compressive residual stresses in the carburized case layer. (author)

  9. Wide-Area Mapping of Forest with National Airborne Laser Scanning and Field Inventory Datasets

    Science.gov (United States)

    Monnet, J.-M.; Ginzler, C.; Clivaz, J.-C.

    2016-06-01

    Airborne laser scanning (ALS) remote sensing data are now available for entire countries such as Switzerland. Methods for the estimation of forest parameters from ALS have been intensively investigated in the past years. However, the implementation of a forest mapping workflow based on available data at a regional level still remains challenging. A case study was implemented in the Canton of Valais (Switzerland). The national ALS dataset and field data of the Swiss National Forest Inventory were used to calibrate estimation models for mean and maximum height, basal area, stem density, mean diameter and stem volume. When stratification was performed based on ALS acquisition settings and geographical criteria, satisfactory prediction models were obtained for volume (R2 = 0.61 with a root mean square error of 47 %) and basal area (respectively 0.51 and 45 %) while height variables had an error lower than 19%. This case study shows that the use of nationwide ALS and field datasets for forest resources mapping is cost efficient, but additional investigations are required to handle the limitations of the input data and optimize the accuracy.

  10. Mapping Carrier Dynamics on Material Surfaces in Space and Time using Scanning Ultrafast Electron Microscopy.

    Science.gov (United States)

    Sun, Jingya; Adhikari, Aniruddha; Shaheen, Basamat S; Yang, Haoze; Mohammed, Omar F

    2016-03-17

    Selectively capturing the ultrafast dynamics of charge carriers on materials surfaces and at interfaces is crucial to the design of solar cells and optoelectronic devices. Despite extensive research efforts over the past few decades, information and understanding about surface-dynamical processes, including carrier trapping and recombination remains extremely limited. A key challenge is to selectively map such dynamic processes, a capability that is hitherto impractical by time-resolved laser techniques, which are limited by the laser's relatively large penetration depth and consequently these techniques record mainly bulk information. Such surface dynamics can only be mapped in real space and time by applying four-dimensional (4D) scanning ultrafast electron microscopy (S-UEM), which records snapshots of materials surfaces with nanometer spatial and subpicosecond temporal resolutions. In this method, the secondary electron (SE) signal emitted from the sample's surface is extremely sensitive to the surface dynamics and is detected in real time. In several unique applications, we spatially and temporally visualize the SE energy gain and loss, the charge carrier dynamics on the surface of InGaN nanowires and CdSe single crystal and its powder film. We also discuss the mechanisms for the observed dynamics, which will be the foundation for future potential applications of S-UEM to a wide range of studies on material surfaces and device interfaces. PMID:26911313

  11. Canopy Gap Mapping from Airborne Laser Scanning: An Assessment of the Positional and Geometrical Accuracy

    Directory of Open Access Journals (Sweden)

    Stéphanie Bonnet

    2015-09-01

    Full Text Available Canopy gaps are small-scale openings in forest canopies which offer suitable micro-climatic conditions for tree regeneration. Field mapping of gaps is complex and time-consuming. Several studies have used Canopy Height Models (CHM derived from airborne laser scanning (ALS to delineate gaps but limited accuracy assessment has been carried out, especially regarding the gap geometry. In this study, we investigate three mapping methods based on raster layers produced from ALS leaf-off and leaf-on datasets: thresholding, per-pixel and per-object supervised classifications with Random Forest. In addition to the CHM, other metrics related to the canopy porosity are tested. The gap detection is good, with a global accuracy up to 82% and consumer’s accuracy often exceeding 90%. The Geometric Accuracy (GAc was analyzed with the gap area, main orientation, gap shape-complexity index and a quantitative assessment index of the matching with reference gaps polygons. The GAc assessment shows difficulties in identifying a method which properly delineates gaps. The performance of CHM-based thresholding was exceeded by that of other methods, especially thresholding of canopy porosity rasters and the per-pixel supervised classification. Beyond assessing the methods performance, we argue the critical need for future ALS-based gap studies to consider the geometric accuracy of results.

  12. Mapping Carrier Dynamics on Material Surfaces in Space and Time using Scanning Ultrafast Electron Microscopy

    KAUST Repository

    Sun, Jingya

    2016-02-25

    Selectively capturing the ultrafast dynamics of charge carriers on materials surfaces and at interfaces is crucial to the design of solar cells and optoelectronic devices. Despite extensive research efforts over the past few decades, information and understanding about surface-dynamical processes, including carrier trapping and recombination remains extremely limited. A key challenge is to selectively map such dynamic processes, a capability that is hitherto impractical by time-resolved laser techniques, which are limited by the laser’s relatively large penetration depth and consequently they record mainly bulk information. Such surface dynamics can only be mapped in real space and time by applying four-dimensional (4D) scanning ultrafast electron microscopy (S-UEM), which records snapshots of materials surfaces with nanometer spatial and sub-picosecond temporal resolutions. In this method, the secondary electron (SE) signal emitted from the sample’s surface is extremely sensitive to the surface dynamics and is detected in real time. In several unique applications, we spatially and temporally visualize the SE energy gain and loss, the charge carrier dynamics on the surface of InGaN nanowires and CdSe single crystals and its powder film. We also provide the mechanisms for the observed dynamics, which will be the foundation for future potential applications of S-UEM to a wide range of studies on material surfaces and device interfaces.

  13. Mapping the Risk of Forest Wind Damage Using Airborne Scanning LiDAR

    Science.gov (United States)

    Saarinen, N.; Vastaranta, M.; Honkavaara, E.; Wulder, M. A.; White, J. C.; Litkey, P.; Holopainen, M.; Hyyppä, J.

    2015-03-01

    Wind damage is known for causing threats to sustainable forest management and yield value in boreal forests. Information about wind damage risk can aid forest managers in understanding and possibly mitigating damage impacts. The objective of this research was to better understand and quantify drivers of wind damage, and to map the probability of wind damage. To accomplish this, we used open-access airborne scanning light detection and ranging (LiDAR) data. The probability of wind-induced forest damage (PDAM) in southern Finland (61°N, 23°E) was modelled for a 173 km2 study area of mainly managed boreal forests (dominated by Norway spruce and Scots pine) and agricultural fields. Wind damage occurred in the study area in December 2011. LiDAR data were acquired prior to the damage in 2008. High spatial resolution aerial imagery, acquired after the damage event (January, 2012) provided a source of model calibration via expert interpretation. A systematic grid (16 m x 16 m) was established and 430 sample grid cells were identified systematically and classified as damaged or undamaged based on visual interpretation using the aerial images. Potential drivers associated with PDAM were examined using a multivariate logistic regression model. Risk model predictors were extracted from the LiDAR-derived surface models. Geographic information systems (GIS) supported spatial mapping and identification of areas of high PDAM across the study area. The risk model based on LiDAR data provided good agreement with detected risk areas (73 % with kappa-value 0,47). The strongest predictors in the risk model were mean canopy height and mean elevation. Our results indicate that open-access LiDAR data sets can be used to map the probability of wind damage risk without field data, providing valuable information for forest management planning.

  14. Semi-automatic mapping of cultural heritage from airborne laser scanning using deep learning

    Science.gov (United States)

    Due Trier, Øivind; Salberg, Arnt-Børre; Holger Pilø, Lars; Tonning, Christer; Marius Johansen, Hans; Aarsten, Dagrun

    2016-04-01

    This paper proposes to use deep learning to improve semi-automatic mapping of cultural heritage from airborne laser scanning (ALS) data. Automatic detection methods, based on traditional pattern recognition, have been applied in a number of cultural heritage mapping projects in Norway for the past five years. Automatic detection of pits and heaps have been combined with visual interpretation of the ALS data for the mapping of deer hunting systems, iron production sites, grave mounds and charcoal kilns. However, the performance of the automatic detection methods varies substantially between ALS datasets. For the mapping of deer hunting systems on flat gravel and sand sediment deposits, the automatic detection results were almost perfect. However, some false detections appeared in the terrain outside of the sediment deposits. These could be explained by other pit-like landscape features, like parts of river courses, spaces between boulders, and modern terrain modifications. However, these were easy to spot during visual interpretation, and the number of missed individual pitfall traps was still low. For the mapping of grave mounds, the automatic method produced a large number of false detections, reducing the usefulness of the semi-automatic approach. The mound structure is a very common natural terrain feature, and the grave mounds are less distinct in shape than the pitfall traps. Still, applying automatic mound detection on an entire municipality did lead to a new discovery of an Iron Age grave field with more than 15 individual mounds. Automatic mound detection also proved to be useful for a detailed re-mapping of Norway's largest Iron Age grave yard, which contains almost 1000 individual graves. Combined pit and mound detection has been applied to the mapping of more than 1000 charcoal kilns that were used by an iron work 350-200 years ago. The majority of charcoal kilns were indirectly detected as either pits on the circumference, a central mound, or both

  15. High-Performance Grouting Mortar Based on Mineral Admixtures

    Directory of Open Access Journals (Sweden)

    Cong Ma

    2015-01-01

    Full Text Available A study on high-performance grouting mortar is reported. The common mortar was modified by mineral admixtures such as gypsum, bauxite, and alunite. The effects of mineral admixtures on the fluidity, setting time, expansion, strength, and other properties of mortar were evaluated experimentally. The microstructure of the modified mortar was characterized by X-ray diffraction, scanning electron microscopy, and mercury intrusion porosimetry. Moreover, the expansive performance and strength of the grouting mortar were verified by anchor pullout test. The results show that the best conditions for gypsum-bauxite grouting mortar are as follows: a water-to-binder ratio of 0.3, a mineral admixture content of ~15%, and a molar ratio K of 2. The ultimate bearing capacity of the gypsum-bauxite grouting mortar anchor increased by 39.6% compared to the common mortar anchor. The gypsum-bauxite grouting mortar has good fluidity, quick-setting, microexpansion, early strength, and high strength performances.

  16. An interactive mapping tool for visualizing lacunarity of laser scanned point clouds

    Science.gov (United States)

    Kania, Adam; Székely, Balázs

    2016-04-01

    Lacunarity, a measure of the spatial distribution of the empty space in a certain model or real space over large spatial scales, is found to be a useful descriptive quantity in many fields using imagery, including, among others, geology, dentistry, neurology. Its application in ecology was suggested more than 20 years ago. The main problem of its application was the lack of appropriate high resolution data. Nowadays, full-waveform laser scanning, also known as FWF LiDAR, provides the tool for mapping the vegetation in unprecedented details and accuracy. Consequently, the lacunarity concept can be revitalized, in order to study the structure of the vegetation in this sense as well. Calculation of lacunarity, even if it is done in two dimensions (2D), is still has its problems: on one hand it is a number-crunching procedure, on the other hand, it produces 4D results: at each 3D point it returns a set of data that are function of scale. These data sets are difficult to visualize, to evaluate, and to compare. In order to solve this problem, an interactive mapping tool has been conceptualized that is designed to manipulate and visualize the data, lets the user set parameters for best visualization or comparison results. The system is able to load large amounts of data, visualize them as lacunarity curves, or map view as horizontal slices or in 3D point clouds coloured according to the user's choice. Lacunarity maps are presented as a series of (usually) horizontal profiles, e.g. rasters, which cells contain color-mapped values of selected lacunarity of the point cloud. As lacunarity is usually analysed in a series of successive windows sizes, the tool can show a series of rasters with sequentially animated lacunarity maps calculated for various window sizes. A very fast switching of colour schemes is possible to facilitate rapid visual feedback to better understand underlying data patterns exposed by lacunarity functions. In the comparison mode, two sites (or two areas

  17. Composition mapping in InGaN by scanning transmission electron microscopy

    International Nuclear Information System (INIS)

    We suggest a method for chemical mapping that is based on scanning transmission electron microscopy (STEM) imaging with a high-angle annular dark field (HAADF) detector. The analysis method uses a comparison of intensity normalized with respect to the incident electron beam with intensity calculated employing the frozen lattice approximation. This procedure is validated with an In0.07Ga0.93N layer with homogeneous In concentration, where the STEM results were compared with energy filtered imaging, strain state analysis and energy dispersive X-ray analysis. Good agreement was obtained, if the frozen lattice simulations took into account static atomic displacements, caused by the different covalent radii of In and Ga atoms. Using a sample with higher In concentration and series of 32 images taken within 42 min scan time, we did not find any indication for formation of In rich regions due to electron beam irradiation, which is reported in literature to occur for the parallel illumination mode. Image simulation of an In0.15Ga0.85N layer that was elastically relaxed with empirical Stillinger-Weber potentials did not reveal significant impact of lattice plane bending on STEM images as well as on the evaluated In concentration profiles for specimen thicknesses of 5, 15 and 50 nm. Image simulation of an abrupt interface between GaN and In0.15Ga0.85N for specimen thicknesses up to 200 nm showed that artificial blurring of interfaces is significantly smaller than expected from a simple geometrical model that is based on the beam convergence only. As an application of the method, we give evidence for the existence of In rich regions in an InGaN layer which shows signatures of quantum dot emission in microphotoluminescence spectroscopy experiments. -- Highlights: → Composition mapping in InGaN using quantitative STEM. → No electron beam induced In clustering in InGaN observed for STEM. → Small influence of lattice plane bending for STEM of InGaN/GaN. → In composition

  18. Mapping Infrared Data on Terrestrial Laser Scanning 3D Models of Buildings

    Directory of Open Access Journals (Sweden)

    Mattia Previtali

    2011-08-01

    Full Text Available A new 3D acquisition and processing procedure to map RGB, thermal IR and near infrared images (NIR on a detailed 3D model of a building is presented. The combination and fusion of different data sources allows the generation of 3D thermal data useful for different purposes such as localization, visualization, and analysis of anomalies in contemporary architecture. The classic approach, which is currently used to map IR images on 3D models, is based on the direct registration of each single image by using space resection or homography. This approach is largely time consuming and in many cases suffers from poor object texture. To overcome these drawbacks, a “bi-camera” system coupling a thermal IR camera to a RGB camera has been setup. The second sensor is used to orient the “bi-camera” through a photogrammetric network also including free-handled camera stations to strengthen the block geometry. In many cases the bundle adjustment can be executed through a procedure for automatic extraction of tie points. Terrestrial laser scanning is adopted to retrieve the 3D model building. The integration of a low-cost NIR camera accumulates further radiometric information on the final 3D model. The use of such a sensor has not been exploited until now to assess the conservation state of buildings. Here some interesting findings from this kind of analysis are reported. The paper shows the methodology and its experimental application to a couple of buildings in the main Campus of Politecnico di Milano University, where IR thermography has previously been carried out for conservation and maintenance purposes.

  19. Vectorial mapping of noncollinear antiferromagnetic structure of semiconducting FeSe surface with spin-polarized scanning tunneling microscopy

    International Nuclear Information System (INIS)

    Antiferromagnetic semiconductors gain increasing interest due to their possible application in spintronics. Using spin polarized scanning tunneling microscopy operating in a vector field, we mapped the noncollinear antiferromagnetic spin structure of a semiconducting hexagonal FeSe surface on the atomic scale. The surface possesses an in-plane compensated Néel structure which is further confirmed by first-principles calculations

  20. Vectorial mapping of noncollinear antiferromagnetic structure of semiconducting FeSe surface with spin-polarized scanning tunneling microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, K. F.; Yang, Fang; Song, Y. R. [Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Zhang, Xiaole [Institute of Natural Sciences, Shanghai Jiao Tong University, Shanghai 200240 (China); The State Key Laboratory of Advanced Optical Communication Systems and Networks, Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Chen, Xianfeng [The State Key Laboratory of Advanced Optical Communication Systems and Networks, Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Liu, Canhua; Qian, Dong; Gao, C. L., E-mail: clgao@sjtu.edu.cn; Jia, Jin-Feng [Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Collaborative Innovation Center of Advanced Microstructures, Nanjing (China); Luo, Weidong, E-mail: wdluo@sjtu.edu.cn [Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Institute of Natural Sciences, Shanghai Jiao Tong University, Shanghai 200240 (China); Collaborative Innovation Center of Advanced Microstructures, Nanjing (China)

    2016-02-08

    Antiferromagnetic semiconductors gain increasing interest due to their possible application in spintronics. Using spin polarized scanning tunneling microscopy operating in a vector field, we mapped the noncollinear antiferromagnetic spin structure of a semiconducting hexagonal FeSe surface on the atomic scale. The surface possesses an in-plane compensated Néel structure which is further confirmed by first-principles calculations.

  1. Mapping metals in Parkinson's and normal brain using rapid-scanning x-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Popescu, Bogdan F Gh; George, Martin J; McCrea, Richard P E; Devon, Richard M; George, Graham N; Hanson, Akela D; Chapman, L Dean; Nichol, Helen [Department of Anatomy and Cell Biology, College of Medicine, University of Saskatchewan SK (Canada); Bergmann, Uwe; Garachtchenko, Alex V; Luening, Katharina [Stanford Synchrotron Radiation Laboratory, Menlo Park, CA (United States); Kelly, Michael E [Division of Neurosurgery, University of Saskatchewan, SK (Canada); Harder, Sheri M [Department of Medical Imaging, University of Saskatchewan, SK (Canada); Pickering, Ingrid J [Department of Geological Sciences, University of Saskatchewan, SK (Canada)], E-mail: h.nichol@usask.ca

    2009-02-07

    Rapid-scanning x-ray fluorescence (RS-XRF) is a synchrotron technology that maps multiple metals in tissues by employing unique hardware and software to increase scanning speed. RS-XRF was validated by mapping and quantifying iron, zinc and copper in brain slices from Parkinson's disease (PD) and unaffected subjects. Regions and structures in the brain were readily identified by their metal complement and each metal had a unique distribution. Many zinc-rich brain regions were low in iron and vice versa. The location and amount of iron in brain regions known to be affected in PD agreed with analyses using other methods. Sample preparation is simple and standard formalin-fixed autopsy slices are suitable. RS-XRF can simultaneously and non-destructively map and quantify multiple metals and holds great promise to reveal metal pathologies associated with PD and other neurodegenerative diseases as well as diseases of metal metabolism.

  2. Mapping Henry: Synchrotron-sourced X-ray fluorescence mapping and ultra-high-definition scanning of an early Tudor portrait of Henry VIII

    Science.gov (United States)

    Dredge, Paula; Ives, Simon; Howard, Daryl L.; Spiers, Kathryn M.; Yip, Andrew; Kenderdine, Sarah

    2015-11-01

    A portrait of Henry VIII on oak panel c. 1535 has recently undergone technical examination to inform questions regarding authorship and the painting's relationship to a group of similar works in the collections of the National Portrait Gallery, London, and the Society of Antiquaries. Due to previous conservation treatments of the painting, the conventional transmission X-radiograph image was difficult to interpret. As a result, the painting underwent high-definition X-ray fluorescence (XRF) elemental mapping on the X-ray fluorescence microscopy beamline of the Australian Synchrotron. Scans were conducted at 12.6 and 18.5 keV, below and above the lead (Pb) L edges, respectively. Typical scan parameters were 120 μm pixel size at 7 ms dwell time, with the largest scan covering an area 545 × 287 mm2 collected in 23 h (10.8 MP). XRF mapping of the panel has guided the conservation treatment of the painting and the revelation of previously obscured features. It has also provided insight into the process of making of the painting. The informative and detailed elemental maps, alongside ultra-high-definition scans of the painting undertaken before and after varnish and over-paint removal, have assisted in comparison of the finely painted details with the London paintings. The resolution offered by the combination of imaging techniques identifies pigment distribution at an extremely fine scale, enabling a new understanding of the artist's paint application.

  3. Mapping Henry: Synchrotron-sourced X-ray fluorescence mapping and ultra-high-definition scanning of an early Tudor portrait of Henry VIII

    International Nuclear Information System (INIS)

    A portrait of Henry VIII on oak panel c. 1535 has recently undergone technical examination to inform questions regarding authorship and the painting's relationship to a group of similar works in the collections of the National Portrait Gallery, London, and the Society of Antiquaries. Due to previous conservation treatments of the painting, the conventional transmission X-radiograph image was difficult to interpret. As a result, the painting underwent high-definition X-ray fluorescence (XRF) elemental mapping on the X-ray fluorescence microscopy beamline of the Australian Synchrotron. Scans were conducted at 12.6 and 18.5 keV, below and above the lead (Pb) L edges, respectively. Typical scan parameters were 120 μm pixel size at 7 ms dwell time, with the largest scan covering an area 545 x 287 mm2 collected in 23 h (10.8 MP). XRF mapping of the panel has guided the conservation treatment of the painting and the revelation of previously obscured features. It has also provided insight into the process of making of the painting. The informative and detailed elemental maps, alongside ultra-high-definition scans of the painting undertaken before and after varnish and over-paint removal, have assisted in comparison of the finely painted details with the London paintings. The resolution offered by the combination of imaging techniques identifies pigment distribution at an extremely fine scale, enabling a new understanding of the artist's paint application. (orig.)

  4. Mapping Henry: Synchrotron-sourced X-ray fluorescence mapping and ultra-high-definition scanning of an early Tudor portrait of Henry VIII

    Energy Technology Data Exchange (ETDEWEB)

    Dredge, Paula; Ives, Simon [Art Gallery of New South Wales (AGNSW), Sydney, NSW (Australia); Howard, Daryl L.; Spiers, Kathryn M. [Australian Synchrotron, Clayton, VIC (Australia); Yip, Andrew [Art Gallery of New South Wales (AGNSW), Sydney, NSW (Australia); University of New South Wales, Laboratory for Innovation in Galleries, Libraries, Archives and Museums (iGLAM), National Institute for Experimental Arts, Sydney, NSW (Australia); Kenderdine, Sarah [University of New South Wales, Laboratory for Innovation in Galleries, Libraries, Archives and Museums (iGLAM), National Institute for Experimental Arts, Sydney, NSW (Australia)

    2015-11-15

    A portrait of Henry VIII on oak panel c. 1535 has recently undergone technical examination to inform questions regarding authorship and the painting's relationship to a group of similar works in the collections of the National Portrait Gallery, London, and the Society of Antiquaries. Due to previous conservation treatments of the painting, the conventional transmission X-radiograph image was difficult to interpret. As a result, the painting underwent high-definition X-ray fluorescence (XRF) elemental mapping on the X-ray fluorescence microscopy beamline of the Australian Synchrotron. Scans were conducted at 12.6 and 18.5 keV, below and above the lead (Pb) L edges, respectively. Typical scan parameters were 120 μm pixel size at 7 ms dwell time, with the largest scan covering an area 545 x 287 mm{sup 2} collected in 23 h (10.8 MP). XRF mapping of the panel has guided the conservation treatment of the painting and the revelation of previously obscured features. It has also provided insight into the process of making of the painting. The informative and detailed elemental maps, alongside ultra-high-definition scans of the painting undertaken before and after varnish and over-paint removal, have assisted in comparison of the finely painted details with the London paintings. The resolution offered by the combination of imaging techniques identifies pigment distribution at an extremely fine scale, enabling a new understanding of the artist's paint application. (orig.)

  5. Mapping Natura 2000 Habitat Conservation Status in a Pannonic Salt Steppe with Airborne Laser Scanning

    Directory of Open Access Journals (Sweden)

    András Zlinszky

    2015-03-01

    Full Text Available Natura 2000 Habitat Conservation Status is currently evaluated based on fieldwork. However, this is proving to be unfeasible over large areas. The use of remote sensing is increasingly encouraged but covering the full range of ecological variables by such datasets and ensuring compatibility with the traditional assessment methodology has not been achieved yet. We aimed to test Airborne Laser Scanning (ALS as a source for mapping all variables required by the local official conservation status assessment scheme and to develop an automated method that calculates Natura 2000 conservation status at 0.5 m raster resolution for 24 km2 of Pannonic Salt Steppe habitat (code 1530. We used multi-temporal (summer and winter ALS point clouds with full-waveform recording and a density of 10 pt/m2. Some required variables were derived from ALS product rasters; others involved vegetation classification layers calculated by machine learning and fuzzy categorization. Thresholds separating favorable and unfavorable values of each variable required by the national assessment scheme were manually calibrated from 10 plots where field-based assessment was carried out. Rasters representing positive and negative scores for each input variable were integrated in a ruleset that exactly follows the Hungarian Natura 2000 assessment scheme for grasslands. Accuracy of each parameter and the final conservation status score and category was evaluated by 10 independent assessment plots. We conclude that ALS is a suitable data source for Natura 2000 assessments in grasslands, and that the national grassland assessment scheme can successfully be used as a GIS processing model for conservation status, ensuring that the output is directly comparable with traditional field based assessments.

  6. Geomorphological Mapping with Terrestrial Laser Scanning and Uav-Based Imaging

    Science.gov (United States)

    Tilly, N.; Kelterbaum, D.; Zeese, R.

    2016-06-01

    High-resolution digital elevation models (DEMs) are useful for the detailed mapping of geomorphological features. Nowadays various sensors and platforms are available to collect 3D data. The presented study compares terrestrial laser scanning (TLS) and low-cost unmanned aerial vehicles (UAV)-based imaging in terms of their usability for capturing small-scale surface structures. In October 2014 and June 2015 measurements with both systems were carried out in an episodically water-filled karst depression under pasture farming in the region of Hohenlohe (Southwest Germany). The overall aims were to establish high-resolution DEMs and monitor changes of the relief caused by dissolution and compare the advantages and drawbacks of both systems for such studies. Due to the short time between the campaigns the clear detection of temporal changes was hardly possible. However, the multi-temporal campaigns allowed an extensive investigation of the usability of both sensors under different environmental conditions. In addition to the remote sensing measurements, the coordinates of several positions in the study area were measured with a RTK-DGPS system as independent reference data sets in both campaigns. The TLS- and UAV-derived DEM heights at these positions were validated against the DGPS-derived heights. The accuracy of the TLS-derived values is supported by low mean differences between TLS and DGPS measurements while the UAV-derived models show a weaker performance. In the future years additional simultaneous measurements with both approaches under more similar vegetation conditions are necessary to detect surface movements. Moreover, by investigating the subsurface the interaction of above and below ground processes might be detected.

  7. Development of Kinematic 3D Laser Scanning System for Indoor Mapping and As-Built BIM Using Constrained SLAM

    Directory of Open Access Journals (Sweden)

    Jaehoon Jung

    2015-10-01

    Full Text Available The growing interest and use of indoor mapping is driving a demand for improved data-acquisition facility, efficiency and productivity in the era of the Building Information Model (BIM. The conventional static laser scanning method suffers from some limitations on its operability in complex indoor environments, due to the presence of occlusions. Full scanning of indoor spaces without loss of information requires that surveyors change the scanner position many times, which incurs extra work for registration of each scanned point cloud. Alternatively, a kinematic 3D laser scanning system, proposed herein, uses line-feature-based Simultaneous Localization and Mapping (SLAM technique for continuous mapping. Moreover, to reduce the uncertainty of line-feature extraction, we incorporated constrained adjustment based on an assumption made with respect to typical indoor environments: that the main structures are formed of parallel or orthogonal line features. The superiority of the proposed constrained adjustment is its reduction for uncertainties of the adjusted lines, leading to successful data association process. In the present study, kinematic scanning with and without constrained adjustment were comparatively evaluated in two test sites, and the results confirmed the effectiveness of the proposed system. The accuracy of the 3D mapping result was additionally evaluated by comparison with the reference points acquired by a total station: the Euclidean average distance error was 0.034 m for the seminar room and 0.043 m for the corridor, which satisfied the error tolerance for point cloud acquisition (0.051 m according to the guidelines of the General Services Administration for BIM accuracy.

  8. Mapping Vineyard Leaf Area Using Mobile Terrestrial Laser Scanners: Should Rows be Scanned On-the-Go or Discontinuously Sampled?

    Science.gov (United States)

    del-Moral-Martínez, Ignacio; Rosell-Polo, Joan R; Company, Joaquim; Sanz, Ricardo; Escolà, Alexandre; Masip, Joan; Martínez-Casasnovas, José A; Arnó, Jaume

    2016-01-01

    The leaf area index (LAI) is defined as the one-side leaf area per unit ground area, and is probably the most widely used index to characterize grapevine vigor. However, LAI varies spatially within vineyard plots. Mapping and quantifying this variability is very important for improving management decisions and agricultural practices. In this study, a mobile terrestrial laser scanner (MTLS) was used to map the LAI of a vineyard, and then to examine how different scanning methods (on-the-go or discontinuous systematic sampling) may affect the reliability of the resulting raster maps. The use of the MTLS allows calculating the enveloping vegetative area of the canopy, which is the sum of the leaf wall areas for both sides of the row (excluding gaps) and the projected upper area. Obtaining the enveloping areas requires scanning from both sides one meter length section along the row at each systematic sampling point. By converting the enveloping areas into LAI values, a raster map of the latter can be obtained by spatial interpolation (kriging). However, the user can opt for scanning on-the-go in a continuous way and compute 1-m LAI values along the rows, or instead, perform the scanning at discontinuous systematic sampling within the plot. An analysis of correlation between maps indicated that MTLS can be used discontinuously in specific sampling sections separated by up to 15 m along the rows. This capability significantly reduces the amount of data to be acquired at field level, the data storage capacity and the processing power of computers. PMID:26797618

  9. Mapping Vineyard Leaf Area Using Mobile Terrestrial Laser Scanners: Should Rows be Scanned On-the-Go or Discontinuously Sampled?

    Directory of Open Access Journals (Sweden)

    Ignacio del-Moral-Martínez

    2016-01-01

    Full Text Available The leaf area index (LAI is defined as the one-side leaf area per unit ground area, and is probably the most widely used index to characterize grapevine vigor. However, LAI varies spatially within vineyard plots. Mapping and quantifying this variability is very important for improving management decisions and agricultural practices. In this study, a mobile terrestrial laser scanner (MTLS was used to map the LAI of a vineyard, and then to examine how different scanning methods (on-the-go or discontinuous systematic sampling may affect the reliability of the resulting raster maps. The use of the MTLS allows calculating the enveloping vegetative area of the canopy, which is the sum of the leaf wall areas for both sides of the row (excluding gaps and the projected upper area. Obtaining the enveloping areas requires scanning from both sides one meter length section along the row at each systematic sampling point. By converting the enveloping areas into LAI values, a raster map of the latter can be obtained by spatial interpolation (kriging. However, the user can opt for scanning on-the-go in a continuous way and compute 1-m LAI values along the rows, or instead, perform the scanning at discontinuous systematic sampling within the plot. An analysis of correlation between maps indicated that MTLS can be used discontinuously in specific sampling sections separated by up to 15 m along the rows. This capability significantly reduces the amount of data to be acquired at field level, the data storage capacity and the processing power of computers.

  10. TIPS bilateral noise reduction in 4D CT perfusion scans produces high-quality cerebral blood flow maps

    International Nuclear Information System (INIS)

    Cerebral computed tomography perfusion (CTP) scans are acquired to detect areas of abnormal perfusion in patients with cerebrovascular diseases. These 4D CTP scans consist of multiple sequential 3D CT scans over time. Therefore, to reduce radiation exposure to the patient, the amount of x-ray radiation that can be used per sequential scan is limited, which results in a high level of noise. To detect areas of abnormal perfusion, perfusion parameters are derived from the CTP data, such as the cerebral blood flow (CBF). Algorithms to determine perfusion parameters, especially singular value decomposition, are very sensitive to noise. Therefore, noise reduction is an important preprocessing step for CTP analysis. In this paper, we propose a time-intensity profile similarity (TIPS) bilateral filter to reduce noise in 4D CTP scans, while preserving the time-intensity profiles (fourth dimension) that are essential for determining the perfusion parameters. The proposed TIPS bilateral filter is compared to standard Gaussian filtering, and 4D and 3D (applied separately to each sequential scan) bilateral filtering on both phantom and patient data. Results on the phantom data show that the TIPS bilateral filter is best able to approach the ground truth (noise-free phantom), compared to the other filtering methods (lowest root mean square error). An observer study is performed using CBF maps derived from fifteen CTP scans of acute stroke patients filtered with standard Gaussian, 3D, 4D and TIPS bilateral filtering. These CBF maps were blindly presented to two observers that indicated which map they preferred for (1) gray/white matter differentiation, (2) detectability of infarcted area and (3) overall image quality. Based on these results, the TIPS bilateral filter ranked best and its CBF maps were scored to have the best overall image quality in 100% of the cases by both observers. Furthermore, quantitative CBF and cerebral blood volume values in both the phantom and the

  11. Effect of Functional Chemical Admixtures on the Performance of Cement Asphalt Mortar Used in Ballastless Track

    Institute of Scientific and Technical Information of China (English)

    JIANG Jinyang; SHE Wei; LI Wei; PAN Li

    2015-01-01

    Chemical admixtures are of paramount importance to the performance of modern cement based composites. In this paper, we performed a series of tests to investigate the effects of chemical admixtures on the cement asphalt mortar (CA mortar), i e, compressive strength, frost resistance, permeability, fatigue resistance, pore structure and microstructure. In particular, two types of chemical admixtures were tested,i e, defoamer (tributyl phosphate (TBP)) and polycarboxylate superplasticizer (PS). The results indicate that the addition of TBP and PS eliminates big bubbles and promotes small non-connected pores forming in matrix. Besides, an optimum dosage of TBP and PS may be determined with respect to the frost resistance, permeability and fatigue resistance of CA mortar. Further elaborative discussions are presented as well as experimental evidences from mercury intrusion porosimetry, scanning electron microscopy and energy dispersive spectroscopy.

  12. Area-Based Mapping of Defoliation of Scots Pine Stands Using Airborne Scanning LiDAR

    OpenAIRE

    Hannu Hyyppä; Michael A. Wulder; Juha Hyyppä; Ville Kankare; Markus Holopainen; Mikko Vastaranta; Päivi Lyytikäinen-Saarenmaa; Tuula Kantola

    2013-01-01

    The mapping of changes in the distribution of insect-caused forest damage remains an important forest monitoring application and challenge. Efficient and accurate methods are required for mapping and monitoring changes in insect defoliation to inform forest management and reporting activities. In this research, we develop and evaluate a LiDAR-driven (Light Detection And Ranging) approach for mapping defoliation caused by the Common pine sawfly (Diprion pini L.). Our method requires plot-level...

  13. Flood hazard mapping by integrating airborne laser scanning data, high resolution images and large scale maps: a case study

    OpenAIRE

    P. Fernandez; G. Gonçalves; Gomes Pereira, L.; M. Moreira

    2012-01-01

    The assessment and management of flood risks framework impose the mapping of flood hazard in potential flood risks areas. Floods in urban environments may happen due to rainfall extreme events and be exacerbated by saturated or impervious surfaces. Flood risk is greater in urban areas. (...)

  14. Total quantitative recording of elemental maps and spectra with a scanning microprobe

    International Nuclear Information System (INIS)

    A system of data recording and analysis has been developed by means of which simultaneously all data from a scanning instrument such as a microprobe can be quantitatively recorded and permanently stored, including spectral outputs from several detectors. Only one scanning operation is required on the specimen. Analysis is then performed on the stored data, which contain quantitative information on distributions of all elements and spectra of all regions

  15. Graph Structure-Based Simultaneous Localization and Mapping Using a Hybrid Method of 2D Laser Scan and Monocular Camera Image in Environments with Laser Scan Ambiguity

    Directory of Open Access Journals (Sweden)

    Taekjun Oh

    2015-07-01

    Full Text Available Localization is an essential issue for robot navigation, allowing the robot to perform tasks autonomously. However, in environments with laser scan ambiguity, such as long corridors, the conventional SLAM (simultaneous localization and mapping algorithms exploiting a laser scanner may not estimate the robot pose robustly. To resolve this problem, we propose a novel localization approach based on a hybrid method incorporating a 2D laser scanner and a monocular camera in the framework of a graph structure-based SLAM. 3D coordinates of image feature points are acquired through the hybrid method, with the assumption that the wall is normal to the ground and vertically flat. However, this assumption can be relieved, because the subsequent feature matching process rejects the outliers on an inclined or non-flat wall. Through graph optimization with constraints generated by the hybrid method, the final robot pose is estimated. To verify the effectiveness of the proposed method, real experiments were conducted in an indoor environment with a long corridor. The experimental results were compared with those of the conventional GMappingapproach. The results demonstrate that it is possible to localize the robot in environments with laser scan ambiguity in real time, and the performance of the proposed method is superior to that of the conventional approach.

  16. Graph Structure-Based Simultaneous Localization and Mapping Using a Hybrid Method of 2D Laser Scan and Monocular Camera Image in Environments with Laser Scan Ambiguity.

    Science.gov (United States)

    Oh, Taekjun; Lee, Donghwa; Kim, Hyungjin; Myung, Hyun

    2015-01-01

    Localization is an essential issue for robot navigation, allowing the robot to perform tasks autonomously. However, in environments with laser scan ambiguity, such as long corridors, the conventional SLAM (simultaneous localization and mapping) algorithms exploiting a laser scanner may not estimate the robot pose robustly. To resolve this problem, we propose a novel localization approach based on a hybrid method incorporating a 2D laser scanner and a monocular camera in the framework of a graph structure-based SLAM. 3D coordinates of image feature points are acquired through the hybrid method, with the assumption that the wall is normal to the ground and vertically flat. However, this assumption can be relieved, because the subsequent feature matching process rejects the outliers on an inclined or non-flat wall. Through graph optimization with constraints generated by the hybrid method, the final robot pose is estimated. To verify the effectiveness of the proposed method, real experiments were conducted in an indoor environment with a long corridor. The experimental results were compared with those of the conventional GMappingapproach. The results demonstrate that it is possible to localize the robot in environments with laser scan ambiguity in real time, and the performance of the proposed method is superior to that of the conventional approach. PMID:26151203

  17. Mapping Morphological and Structural Properties of Lead Halide Perovskites by Scanning Nanofocus XRD

    OpenAIRE

    Lilliu, Samuele; Dane, Thomas G.; Griffin, Jonathan; Alsari, Mejd; Barrows, Alexander T.; Dahlem, Marcus S.; Friend, Richard H.; Lidzey, David G.; Macdonald, J. Emyr

    2016-01-01

    Scanning nanofocus X-ray diffraction (nXRD) performed at a synchrotron is used for the first time to simultaneously probe the morphology and the structural properties of spin-coated CH3NH3PbI3 (MAPI) perovskite films for photovoltaic devices. MAPI films are spin-coated on a Si/SiO2/PEDOT:PSS substrate held at different temperatures during the deposition in order to tune the perovskite film coverage, and then investigated by nXRD, scanning electron microscopy (SEM) and grazing incidence wide a...

  18. Test of the Capability of Laser Line Scan Technology to Support Benthic Habitat Mapping in Coral Reef Ecosystems, Maui Island, November 2006

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The utility of Laser Line Scan (LLS) Technology for optical validation of benthic habitat map data from coral reef ecosystems was tested with a deployment of a...

  19. Scanning micro-Hall probe mapping of magnetic flux distributions and current densities in YBa2Cu3O7

    International Nuclear Information System (INIS)

    Mapping of the magnetic flux density Bz (perpendicular to the film plane) for a YBa2Cu3O7 thin-film sample was carried out using a scanning micro-Hall probe. The sheet magnetization and sheet current densities were calculated from the Bz distributions. From the known sheet magnetization, the tangential (Bx,y) and normal components of the flux density B were calculated in the vicinity of the film. It was found that the sheet current density was mostly determined by 2Bx,y/d, where d is the film thickness. The evolution of flux penetration as a function of applied field will be shown

  20. Mapping Infrared Data on Terrestrial Laser Scanning 3D Models of Buildings

    OpenAIRE

    Mattia Previtali; Elisabetta Rosina; Marco Scaioni; Luigi Barazzetti; Mario Ivan Alba

    2011-01-01

    A new 3D acquisition and processing procedure to map RGB, thermal IR and near infrared images (NIR) on a detailed 3D model of a building is presented. The combination and fusion of different data sources allows the generation of 3D thermal data useful for different purposes such as localization, visualization, and analysis of anomalies in contemporary architecture. The classic approach, which is currently used to map IR images on 3D models, is based on the direct registration of each single i...

  1. Genetic admixture and population substructure in Guanacaste Costa Rica.

    Directory of Open Access Journals (Sweden)

    Zhaoming Wang

    Full Text Available The population of Costa Rica (CR represents an admixture of major continental populations. An investigation of the CR population structure would provide an important foundation for mapping genetic variants underlying common diseases and traits. We conducted an analysis of 1,301 women from the Guanacaste region of CR using 27,904 single nucleotide polymorphisms (SNPs genotyped on a custom Illumina InfiniumII iSelect chip. The program STRUCTURE was used to compare the CR Guanacaste sample with four continental reference samples, including HapMap Europeans (CEU, East Asians (JPT+CHB, West African Yoruba (YRI, as well as Native Americans (NA from the Illumina iControl database. Our results show that the CR Guanacaste sample comprises a three-way admixture estimated to be 43% European, 38% Native American and 15% West African. An estimated 4% residual Asian ancestry may be within the error range. Results from principal components analysis reveal a correlation between genetic and geographic distance. The magnitude of linkage disequilibrium (LD measured by the number of tagging SNPs required to cover the same region in the genome in the CR Guanacaste sample appeared to be weaker than that observed in CEU, JPT+CHB and NA reference samples but stronger than that of the HapMap YRI sample. Based on the clustering pattern observed in both STRUCTURE and principal components analysis, two subpopulations were identified that differ by approximately 20% in LD block size averaged over all LD blocks identified by Haploview. We also show in a simulated association study conducted within the two subpopulations, that the failure to account for population stratification (PS could lead to a noticeable inflation in the false positive rate. However, we further demonstrate that existing PS adjustment approaches can reduce the inflation to an acceptable level for gene discovery.

  2. African ancestry and its correlation to type 2 diabetes in African Americans: a genetic admixture analysis in three U.S. population cohorts.

    Directory of Open Access Journals (Sweden)

    Ching-Yu Cheng

    Full Text Available The risk of type 2 diabetes is approximately 2-fold higher in African Americans than in European Americans even after adjusting for known environmental risk factors, including socioeconomic status (SES, suggesting that genetic factors may explain some of this population difference in disease risk. However, relatively few genetic studies have examined this hypothesis in a large sample of African Americans with and without diabetes. Therefore, we performed an admixture analysis using 2,189 ancestry-informative markers in 7,021 African Americans (2,373 with type 2 diabetes and 4,648 without from the Atherosclerosis Risk in Communities Study, the Jackson Heart Study, and the Multiethnic Cohort to 1 determine the association of type 2 diabetes and its related quantitative traits with African ancestry controlling for measures of SES and 2 identify genetic loci for type 2 diabetes through a genome-wide admixture mapping scan. The median percentage of African ancestry of diabetic participants was slightly greater than that of non-diabetic participants (study-adjusted difference = 1.6%, P<0.001. The odds ratio for diabetes comparing participants in the highest vs. lowest tertile of African ancestry was 1.33 (95% confidence interval 1.13-1.55, after adjustment for age, sex, study, body mass index (BMI, and SES. Admixture scans identified two potential loci for diabetes at 12p13.31 (LOD = 4.0 and 13q14.3 (Z score = 4.5, P = 6.6 × 10(-6. In conclusion, genetic ancestry has a significant association with type 2 diabetes above and beyond its association with non-genetic risk factors for type 2 diabetes in African Americans, but no single gene with a major effect is sufficient to explain a large portion of the observed population difference in risk of diabetes. There undoubtedly is a complex interplay among specific genetic loci and non-genetic factors, which may both be associated with overall admixture, leading to the observed ethnic differences in diabetes

  3. Low-cost Mobile Laser Scanning and its Feasibility for Environmental Mapping

    OpenAIRE

    Jaakkola, Anttoni

    2015-01-01

    Mobile laser scanning is a measurement technology that combines accurate positioning and attitude information from navigation satellites and inertial sensors with distance measurements from a laser scanner into a point cloud that represents the geometry of the environment surrounding the measurement platform. This geometrical information can be utilized in a variety of applications ranging from 3D city modelling and infrastructure maintenance to forestry and environmental monitoring. In th...

  4. Digital mapping of side-scan sonar data with the Woods Hole Image Processing System software

    Science.gov (United States)

    Paskevich, Valerie F.

    1992-01-01

    Since 1985, the Branch of Atlantic Marine Geology has been involved in collecting, processing and digitally mosaicking high and low resolution sidescan sonar data. In the past, processing and digital mosaicking has been accomplished with a dedicated, shore-based computer system. Recent development of a UNIX-based image-processing software system includes a series of task specific programs for pre-processing sidescan sonar data. To extend the capabilities of the UNIX-based programs, development of digital mapping techniques have been developed. This report describes the initial development of an automated digital mapping procedure. Included is a description of the programs and steps required to complete the digital mosaicking on a UNIXbased computer system, and a comparison of techniques that the user may wish to select.

  5. Study of the mapping mechanism of ferroelectric domains with the scanning force microscope

    International Nuclear Information System (INIS)

    The piezo-force microscopy (PFM) allows the mapping of ferroelectric domains until the nanometer range. In spite of its simple function principle it was hitherto not completely understood. In ordser to develop the PFM further to a quantitative analysis method its methodical aspects were analyzed. It was shown that the fundamental mapping mechanism is based on the inverse piezo-effect. Different artefacts to be found in the literature could therefore be reduced to a measurement background. Furthermore the influence of the electrode geometry was analyzed. The width of doamin walls was systematically measured and simulated with a mode, whereby a maximal resolution of 17 nm was reached. By the development of a correction procedure for the exact detection of the forces acting on the spring-beam the lateral signals measured on domain walls could by newly interpreted. So the ''Lateral Electrostatic Force Microscopy'' was developed

  6. Hotspot Decorations Map Plasmonic Patterns with the Resolution of Scanning Probe Techniques

    OpenAIRE

    Valev, V. K.; Silhanek, A. V.; Jeyaram, Y.; Denkova, D.; DE CLERCQ, Ben; Petkov, V.; X. Zheng; Volskiy, V.; Gillijns, W.; Vandenbosch, G.A. E.; Aktsipetrov, O.A.; AMELOOT, Marcel; Moshchalkov, V.V.; Verbiest, T.

    2011-01-01

    In high definition mapping of the plasmonic patterns on the surfaces of nanostructures, the diffraction limit of light remains an important obstacle. Here we demonstrate that this diffraction limit can be completely circumvented. We show that upon illuminating nanostructures made of nickel and palladium, the resulting surface-plasmon pattern is imprinted on the structures themselves; the hotspots (regions of local field enhancement) are decorated with overgrowths, allowing for their subsequen...

  7. Further characterization of theobroma oil-beeswax admixtures as lipid matrices for improved drug delivery systems.

    Science.gov (United States)

    Attama, A A; Schicke, B C; Müller-Goymann, C C

    2006-11-01

    There is an increasing interest in lipid based drug delivery systems due to factors such as better characterization of lipidic excipients and formulation versatility and the choice of different drug delivery systems. It is important to know the thermal characteristics, crystal habit, texture, and appearance of a new lipid matrix when determining its suitability for use in certain pharmaceutical application. It is line with this that this research was embarked upon to characterize mixtures of beeswax and theobroma oil with a view to applying their admixtures in drug delivery systems such as solid lipid nanoparticles and nanostructured lipid carriers. Admixtures of theobroma oil and beeswax were prepared to contain 25% w/w, 50% w/w, and 75% w/w of theobroma oil. The admixtures were analyzed by differential scanning calorimetry (DSC), small angle X-ray diffraction (SAXD), wide angle X-ray diffraction (WAXD), and isothermal heat conduction microcalorimetry (IMC). The melting behavior and microstructures of the lipid admixtures were monitored by polarized light microscopy (PLM). Transmission electron microscopy (TEM) was used to study the internal structures of the lipid bases. DSC traces indicated that the higher melting peaks were roughly constant for the different admixtures, but lower melting peaks significantly increased (p beeswax in all the lipid matrix admixtures at all stages of the study. PLM micrographs revealed differences with regard to the thermal and optical behaviors depending on the composition of the matrix. The lipid matrix consisting of 75% w/w of theobroma oil showed a spherulite texture after 4 weeks of isothermal storage. Crystallization exotherms of lipid matrices containing 50% w/w and 25% w/w of theobroma oil showed change in modification after 30 min with the latter having a greater time-dependent crystallization. Generally, low non-integral Avrami exponents and growth rate constants were obtained for all the lipid matrices, with the admixture

  8. Mapping tree health using airborne full-waveform laser scans and hyperspectral imagery: a case study for floodplain eucalypt forest

    Science.gov (United States)

    Shendryk, I.; Tulbure, M. G.; Broich, M.

    2014-12-01

    Barmah-Millewa Forest (BMF), the largest River Red Gum forest in the world, located in south-eastern Australia is suffering from severe dieback, thus diminishing its ecological and economical value. Previous research showed that dieback is a good predictor of the forest health and stressed the need for BMF health mapping and change monitoring. In this respect, airborne laser scanning and hyperspectral imaging offer extensive spatial and spectral coverage of measurements and represent an ideal tool for forest health mapping at individual tree scale. The aim of this project is to quantify the health of individual, structurally complex floodplain eucalypt trees by integrating airborne hyperspectral imagery, full-waveform laser scans and field measurements. An aerial survey, conducted in May 2014, was designed to provide a representative sample of BMF tree health. The positioning of 17 flight lines aimed to capture the heterogeneity of the forest health and flood frequency. Preliminary analysis of the aerial remote sensing data with regards to chlorophyll concentrations, dieback levels and canopy densities allowed us to target our field campaign (conducted in June 2014). Field measurements included accurate position measurements, LAI, visual assessment, spectral measurement and mensuration of individual trees in 30 m2 plots. For detection of individual tree trunks from airborne laser scans we used a novel approach based on Euclidean distance clustering, taking advantage of the intensity and pulse width difference between woody and leaf tree compartments. The detected trunks were used to seed a minimum cut algorithm for tree crown delineation. In situ measurements confirmed the high structural diversity of the forest and allowed the calibration of the tree detection algorithm. An overall accuracy of the tree detection of 54% and 67% was achieved for trees with circumference over 40 cm and over 100 cm respectively. As a further step, 3D point clusters representing

  9. Study on incidence of pulmonary embolism in patients with cardiac pacemakers using lung perfusion mapping and ventilation scanning

    International Nuclear Information System (INIS)

    We investigated pulmonary perfusion mapping and ventilation scanning employing 99mTC-MMA and 81mKr-Gas in patients with DDD and VVI cardiac pacemaker implantation. In 51 cases among 175 patients we observed some defects which matched the results from lung perfusion scanning in the pulmonary segments and sub-segments. These were diagnosed as pulmonary embolism after the possibility of other pulmonary diseases was rejected. The incidence rate of pulmonary embolism in patients with VVI (Ventricular pacing/sensing, inhibited type) pacemakers was 47 out of 138, or 34.1%, especially for those who received a pulmonary scanning examination whithin 6 months after pacemaker implantation. In contrast, those who were examined after 6 months had lower rates as well as chronological factors. The incidence rate of pulmonary embolism in 37 patients with DDD (Double chamber pacing/sensing, double modes of response) pacemakers was 10.8%, considerably lower than that for patients with VVI pacemakers. Therefore, one main factor of pulmonary embolism in patients with pacemakers could be the non-physiological phase of the contractions of both atria and ventricles. Other factors, such as the presence of foreign bodies in the endocardium, aging, and hypertension, could also promote pulmonary embolism. (author)

  10. A Genome Scan for Modifiers of Age at Onset in Huntington Disease: The HD MAPS Study

    OpenAIRE

    Li, Jian-Liang; Hayden, Michael R.; Almqvist, Elisabeth W.; Brinkman, Ryan R; Durr, Alexandra; Dodé, Catherine; Morrison, Patrick J.; Suchowersky, Oksana; Ross, Christopher A.; Margolis, Russell L.; Rosenblatt, Adam; Gómez-Tortosa, Estrella; Cabrero, David Mayo; Novelletto, Andrea; Frontali, Marina

    2003-01-01

    Huntington disease (HD) is caused by the expansion of a CAG repeat within the coding region of a novel gene on 4p16.3. Although the variation in age at onset is partly explained by the size of the expanded repeat, the unexplained variation in age at onset is strongly heritable (h2=0.56), which suggests that other genes modify the age at onset of HD. To identify these modifier loci, we performed a 10-cM density genomewide scan in 629 affected sibling pairs (295 pedigrees and 695 individuals), ...

  11. Atomic-scale mapping of electronic structures across heterointerfaces by cross-sectional scanning tunneling microscopy

    Science.gov (United States)

    Chiu, Ya-Ping; Huang, Bo-Chao; Shih, Min-Chuan; Huang, Po-Cheng; Chen, Chun-Wei

    2015-09-01

    Interfacial science has received much attention recently based on the development of state-of-the-art analytical tools that can create and manipulate the charge, spin, orbital, and lattice degrees of freedom at interfaces. Motivated by the importance of nanoscale interfacial science that governs device operation, we present a technique to probe the electronic characteristics of heterointerfaces with atomic resolution. In this work, the interfacial characteristics of heteroepitaxial structures are investigated and the fundamental mechanisms that pertain in these systems are elucidated through cross-sectional scanning tunneling microscopy (XSTM). The XSTM technique is employed here to directly observe epitaxial interfacial structures and probe local electronic properties with atomic-level capability. Scanning tunneling microscopy and spectroscopy experiments with atomic precision provide insight into the origin and spatial distribution of electronic properties across heterointerfaces. The first part of this report provides a brief description of the cleavage technique and spectroscopy analysis in XSTM measurements. The second part addresses interfacial electronic structures of several model heterostructures in current condensed matter research using XSTM. Topics to be discussed include high-κ‘s/III-V’s semiconductors, polymer heterojunctions, and complex oxide heterostructures, which are all material systems whose investigation using this technique is expected to benefit the research community. Finally, practical aspects and perspectives of using XSTM in interface science are presented.

  12. Submolecular Electronic Mapping of Single Cysteine Molecules by in Situ Scanning Tunneling Imaging

    DEFF Research Database (Denmark)

    Zhang, Jingdong; Chi, Qijin; Nazmutdinov, R. R.;

    2009-01-01

    We have used L-Cysteine (Cys) as a model system to study the surface electronic structures of single molecules at the submolecular level in aqueous buffer solution by a combination of electrochemical scanning tunneling microscopy (in situ STM), electrochemistry including voltammetry and chronocou......We have used L-Cysteine (Cys) as a model system to study the surface electronic structures of single molecules at the submolecular level in aqueous buffer solution by a combination of electrochemical scanning tunneling microscopy (in situ STM), electrochemistry including voltammetry and...... contributed mainly from three chemical moieties: thiol (-SH), carboxylic (-COOH), and amine (-NH2) groups. The contrasts of the three subunits depend on the environment (e.g., pH), which affects the electronic structure of adsorbed species. From the DFT computations focused on single molecules, rational...... bulk. The correlation between physical location and electronic contrast of the adsorbed molecules was also revealed by the computational data. The present study shows that cysteine packing in the adlayer on Au(110) from the liquid environment is in contrast to that from the ultrahigh-vacuum environment...

  13. Atomic-scale mapping of electronic structures across heterointerfaces by cross-sectional scanning tunneling microscopy

    International Nuclear Information System (INIS)

    Interfacial science has received much attention recently based on the development of state-of-the-art analytical tools that can create and manipulate the charge, spin, orbital, and lattice degrees of freedom at interfaces. Motivated by the importance of nanoscale interfacial science that governs device operation, we present a technique to probe the electronic characteristics of heterointerfaces with atomic resolution. In this work, the interfacial characteristics of heteroepitaxial structures are investigated and the fundamental mechanisms that pertain in these systems are elucidated through cross-sectional scanning tunneling microscopy (XSTM). The XSTM technique is employed here to directly observe epitaxial interfacial structures and probe local electronic properties with atomic-level capability. Scanning tunneling microscopy and spectroscopy experiments with atomic precision provide insight into the origin and spatial distribution of electronic properties across heterointerfaces. The first part of this report provides a brief description of the cleavage technique and spectroscopy analysis in XSTM measurements. The second part addresses interfacial electronic structures of several model heterostructures in current condensed matter research using XSTM. Topics to be discussed include high-κ‘s/III–V’s semiconductors, polymer heterojunctions, and complex oxide heterostructures, which are all material systems whose investigation using this technique is expected to benefit the research community. Finally, practical aspects and perspectives of using XSTM in interface science are presented. (topical review)

  14. Early hydration cement Effect of admixtures superplasticizers

    Directory of Open Access Journals (Sweden)

    Puertas, F.

    2001-06-01

    Full Text Available Early hydration of portland cement with superplasticizer admixtures of different nature has been studied. These admixtures were: one based on melamine synthetic, other based on vinyl copolymer and other based on polyacrylate copolymers. The dosage of the formers were constant (1% weigth of cement and for the third, the influence of admixture dosage was also evaluated, giving dosage values among 1-0.3%. The pastes obtained were studied by conduction calorimetry, XRD and FTIR. Also the apparent fluidity was determined by "Minislump" test. The main results obtained were: a superplasticizers admixtures used, regardless of their nature and for the polycarboxilate one the dosage, retard the silicate hydration (specially, alite phase, b The ettringite formation is affected by the nature of the admixture. cA relationship between the dosage of admixture based on polycarboxilates and the time at the acceleration has been established. A lineal relation (y = 11.03 + 16.05x was obtained. From these results is possible to know, in function of dosage admixture, the time when the masive hydration products and the setting times are produced. Also the total heat releases in these reactions is independent of the nature and dosage of admixture, saying that in all cases the reactions are the same.

    En el presente trabajo se ha estudiado la hidratación inicial de un cemento portland aditivado con superplastificantes de diferente naturaleza. Dichos aditivos fueron: uno basado en melaminas sintéticas, otro en copolímeros vinilicos y otro en policarboxilatos. La dosificación de los dos primeros se fijó constante en 1% en peso con relación al cemento, mientras que para el tercero se evaluó, también, la influencia de la dosificación, tomando proporciones desde el 1% hasta el 0,3%. Las pastas obtenidas se estudiaron por: calorimetría de conducción, DRX y FTIR. También se determinó la fluidez de la pasta a través del ensayo del "Minislump ". Los

  15. Nanoscale magnetic field mapping with a single spin scanning probe magnetometer

    Energy Technology Data Exchange (ETDEWEB)

    Rondin, L.; Tetienne, J.-P.; Spinicelli, P.; Roch, J.-F.; Jacques, V. [Laboratoire de Photonique Quantique et Moleculaire, Ecole Normale Superieure de Cachan and CNRS UMR 8537, 94235 Cachan Cedex (France); Dal Savio, C.; Karrai, K. [Attocube systems AG, Koeniginstrasse 11A RGB, Munich 80539 (Germany); Dantelle, G. [Laboratoire de Physique de la Matiere Condensee, Ecole Polytechnique and CNRS UMR 7643, 91128 Palaiseau (France); Thiaville, A.; Rohart, S. [Laboratoire de Physique des Solides, Universite Paris-Sud and CNRS UMR 8502, 91405 Orsay (France)

    2012-04-09

    We demonstrate quantitative magnetic field mapping with nanoscale resolution, by applying a lock-in technique on the electron spin resonance frequency of a single nitrogen-vacancy defect placed at the apex of an atomic force microscope tip. In addition, we report an all-optical magnetic imaging technique which is sensitive to large off-axis magnetic fields, thus extending the operation range of diamond-based magnetometry. Both techniques are illustrated by using a magnetic hard disk as a test sample. Owing to the non-perturbing and quantitative nature of the magnetic probe, this work should open up numerous perspectives in nanomagnetism and spintronics.

  16. Nanoscale magnetic field mapping with a single spin scanning probe magnetometer

    International Nuclear Information System (INIS)

    We demonstrate quantitative magnetic field mapping with nanoscale resolution, by applying a lock-in technique on the electron spin resonance frequency of a single nitrogen-vacancy defect placed at the apex of an atomic force microscope tip. In addition, we report an all-optical magnetic imaging technique which is sensitive to large off-axis magnetic fields, thus extending the operation range of diamond-based magnetometry. Both techniques are illustrated by using a magnetic hard disk as a test sample. Owing to the non-perturbing and quantitative nature of the magnetic probe, this work should open up numerous perspectives in nanomagnetism and spintronics.

  17. Mapping the dislocation sub-structure of deformed polycrystalline Ni by scanning microbeam diffraction topography

    International Nuclear Information System (INIS)

    When subjected to plastic deformation, grains within ductile face-centred cubic polycrystals fragment into 'soft', low dislocation density cells separated by 'hard', dislocation-rich walls. Using a narrow-bandwidth, sub-micrometre X-ray beam, we have mapped the deformation structure inside a single grain within a deformed Ni polycrystal. Dislocation multiplication and entanglement was found to vary depending on the physical dimensions of the grain. The method we use overcomes current limitations in classical X-ray topography allowing topographic images to be formed from small, highly deformed grains.

  18. Rapid-1 Hardening Accelerator Concrete Admixture

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    SIKA Rapid-1 is a concrete admixture that allows the development of very early high strengths in concrete consisting of commonly used mix components. Unlike concrete set accelerators, it does not reduce set time or long-term strength, and it does not corrode steel reinforcing. This hardening accelerator allows placement of fresh concrete without early stiffening, followed by a period of very rapid strength gain after initial set.

  19. State of the water in crosslinked sulfonated poly(ether ether ketone). Two-dimensional differential scanning calorimetry correlation mapping

    Energy Technology Data Exchange (ETDEWEB)

    Al Lafi, Abdul G. [Department of Chemistry, Atomic Energy Commission, Damascus, P.O. Box 6091 (Syrian Arab Republic); Hay, James N., E-mail: cscientific9@aec.org.sy [The School of Metallurgy and Materials, College of Physical Sciences and Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)

    2015-07-20

    Highlights: • 2D-DSC mapping was applied to analyze the heat flow responses of hydrated crosslinked sPEEK. • Two types of loosely bond water were observed. • The first was bond to the sulfonic acid groups and increased with ion exchange capacity. • The second was attributed to the polar groups introduced by ions irradiation and increased with crosslinking degree. • DSC combined with 2D mapping provides a powerful tool for polymer structural determination. - Abstract: This paper reports the first application of two-dimensional differential scanning calorimetry correlation mapping, 2D-DSC-CM to analyze the heat flow responses of sulphonated poly(ether ether ketone), sPEEK, films having different ion exchange capacity and degrees of crosslinks. With the help of high resolution and high sensitivity of 2D-DSC-CM, it was possible to locate two types of loosely bound water within the structure of crosslinked sPEEK. The first was bound to the sulfonic acid groups and dependent on the ion exchange capacity of the sPEEK. The second was bound to other polar groups, either introduced by irradiation with ions and dependent on the crosslinking degree or present in the polymer such as the carbonyl groups or terminal units. The results suggest that the ability of the sulfonic acid groups in the crosslinked sPEEK membranes to adsorb water molecules is increased by crosslinking, probably due to the better close packing efficiency of the crosslinked samples. DSC combined with 2D correlation mapping provides a fast and powerful tool for polymer structural determination.

  20. State of the water in crosslinked sulfonated poly(ether ether ketone). Two-dimensional differential scanning calorimetry correlation mapping

    International Nuclear Information System (INIS)

    Highlights: • 2D-DSC mapping was applied to analyze the heat flow responses of hydrated crosslinked sPEEK. • Two types of loosely bond water were observed. • The first was bond to the sulfonic acid groups and increased with ion exchange capacity. • The second was attributed to the polar groups introduced by ions irradiation and increased with crosslinking degree. • DSC combined with 2D mapping provides a powerful tool for polymer structural determination. - Abstract: This paper reports the first application of two-dimensional differential scanning calorimetry correlation mapping, 2D-DSC-CM to analyze the heat flow responses of sulphonated poly(ether ether ketone), sPEEK, films having different ion exchange capacity and degrees of crosslinks. With the help of high resolution and high sensitivity of 2D-DSC-CM, it was possible to locate two types of loosely bound water within the structure of crosslinked sPEEK. The first was bound to the sulfonic acid groups and dependent on the ion exchange capacity of the sPEEK. The second was bound to other polar groups, either introduced by irradiation with ions and dependent on the crosslinking degree or present in the polymer such as the carbonyl groups or terminal units. The results suggest that the ability of the sulfonic acid groups in the crosslinked sPEEK membranes to adsorb water molecules is increased by crosslinking, probably due to the better close packing efficiency of the crosslinked samples. DSC combined with 2D correlation mapping provides a fast and powerful tool for polymer structural determination

  1. Permeability mapping in porous media by magnetization prepared centric-scan SPRITE

    Science.gov (United States)

    Romanenko, Konstantin V.; Balcom, Bruce J.

    2011-02-01

    The ability of porous media to transmit fluids is commonly referred to as permeability. The concept of permeability is central for hydrocarbon recovery from petroleum reservoirs and for studies of groundwater flow in aquifers. Spatially resolved measurements of permeability are of great significance for fluid dynamics studies. A convenient concept of local Darcy's law is suggested for parallel flow systems. The product of porosity and mean velocity images in the plane across the average flow direction is directly proportional to permeability. Single Point Ramped Imaging with T 1 Enhancement (SPRITE) permits reliable quantification of local fluid content and flow in porous media. It is particularly advantageous for reservoir rocks characterized by fast magnetic relaxation of a saturating fluid. Velocity encoding using the Cotts pulsed field gradient scheme improves the accuracy of measured flow parameters. The method is illustrated through measurements of 2D permeability maps in a capillary bundle, glass bead packs and composite sandstone samples.

  2. The architecture of cartilage: Elemental maps and scanning transmission ion microscopy/tomography

    Science.gov (United States)

    Reinert, Tilo; Reibetanz, Uta; Schwertner, Michael; Vogt, Jürgen; Butz, Tilman; Sakellariou, Arthur

    2002-04-01

    Articular cartilage is not just a jelly-like cover of the bone within the joints but a highly sophisticated architecture of hydrated macromolecules, collagen fibrils and cartilage cells. Influences on the physiological balance due to age-related or pathological changes can lead to malfunction and subsequently to degradation of the cartilage. Many activities in cartilage research are dealing with the architecture of joint cartilage but have limited access to elemental distributions. Nuclear microscopy is able to yield spatially resolved elemental concentrations, provides density information and can visualise the arrangement of the collagen fibres. The distribution of the cartilage matrix can be deduced from the elemental and density maps. The findings showed a varying content of collagen and proteoglycan between zones of different cell maturation. Zones of higher collagen content are characterised by aligned collagen fibres that can form tubular structures. Recently we focused on STIM tomography to investigate the three dimensional arrangement of the collagen structures.

  3. The architecture of cartilage: Elemental maps and scanning transmission ion microscopy/tomography

    International Nuclear Information System (INIS)

    Articular cartilage is not just a jelly-like cover of the bone within the joints but a highly sophisticated architecture of hydrated macromolecules, collagen fibrils and cartilage cells. Influences on the physiological balance due to age-related or pathological changes can lead to malfunction and subsequently to degradation of the cartilage. Many activities in cartilage research are dealing with the architecture of joint cartilage but have limited access to elemental distributions. Nuclear microscopy is able to yield spatially resolved elemental concentrations, provides density information and can visualise the arrangement of the collagen fibres. The distribution of the cartilage matrix can be deduced from the elemental and density maps. The findings showed a varying content of collagen and proteoglycan between zones of different cell maturation. Zones of higher collagen content are characterised by aligned collagen fibres that can form tubular structures. Recently we focused on STIM tomography to investigate the three dimensional arrangement of the collagen structures

  4. BOOMERanG a scanning telescope for 10 arcminutes resolution CMB maps

    CERN Document Server

    Masi, S; Artusa, R; Bock, J J; Boscaleri, A; Crill, B P; De Bernardis, P; De Troia, G; Farese, P C; Giacometti, M; Hristov, V V; Iacoangeli, A; Lange, A E; Lee, A T; Martinis, L; Mason, P V; Mauskopf, P D; Melchiorri, F; Miglio, L; Montroy, T; Netterfield, C B; Pascale, E; Piacentini, F; Richards, P L; Romeo, G; Ruhl, J E; Scaramuzzi, F

    1999-01-01

    The BOOMERanG experiment is a stratospheric balloon telescope intended to measure the Cosmic Microwave Background anisotropy at angular scales between a few degrees and ten arcminutes. The experiment features a wide focal plane with 16 detectors in the frequency bands centered at 90, 150, 220, 400 GHz, with FWHM ranging between 18 and 10 arcmin. It will be flown on a long duration (7-14 days) flight circumnavigating Antarctica at the end of 1998. The instrument was flown with a reduced focal plane (6 detectors, 90 and 150 GHz bands, 25 to 15 arcmin FWHM) on a qualification flight from Texas, in August 1997. A wide (~300 sq. deg, i.e. about 5000 independent beams at 150 GHz) sky area was mapped in the constellations of Capricornus, Aquarius, Cetus, with very low foreground contamination. The instrument was calibrated using the CMB dipole and observations of Jupiter. The LDB version of the instrument has been qualified and shipped to Antarctica.

  5. Extended focused imaging and depth map reconstruction in optical scanning holography.

    Science.gov (United States)

    Ren, Zhenbo; Chen, Ni; Lam, Edmund Y

    2016-02-10

    In conventional microscopy, specimens lying within the depth of field are clearly recorded whereas other parts are blurry. Although digital holographic microscopy allows post-processing on holograms to reconstruct multifocus images, it suffers from defocus noise as a traditional microscope in numerical reconstruction. In this paper, we demonstrate a method that can achieve extended focused imaging (EFI) and reconstruct a depth map (DM) of three-dimensional (3D) objects. We first use a depth-from-focus algorithm to create a DM for each pixel based on entropy minimization. Then we show how to achieve EFI of the whole 3D scene computationally. Simulation and experimental results involving objects with multiple axial sections are presented to validate the proposed approach. PMID:26906373

  6. Side-scan sonar mapping of lake trout spawning habitat in northern Lake Michigan

    Science.gov (United States)

    Edsall, Thomas A.; Poe, Thomas P.; Nester, Robert T.; Brown, Charles L.

    1989-01-01

    Native stocks of lake trout Salvelinus namaycush were virtually or completely extirpated from the lower four Great Lakes by the early 1960s. The failure of early attempts to reestablish self-sustaining populations of lake trout was attributed partly to the practice of stocking hatcheryreared juveniles at locations and over substrates that had not been used in the past for spawning by native fish. Subsequent attempts to improve the selection of stocking locations were impeded by the lack of reliable information on the distribution of substrates on historical spawning grounds. Here we demonstrate the potential of side-scan sonar to substantially expand the data base needed to pinpoint the location of substrates where lake trout eggs, fry, or juveniles could be stocked to maximize survival and help ensure that survivors returning to spawn would encounter suitable substrates. We also describe the substrates and bathymetry of large areas on historical lake trout spawning grounds in the Fox Island Lake Trout Sanctuary in northern Lake Michigan. These areas could be used to support a contemporary self-sustaining lake trout population in the sanctuary and perhaps also in adjacent waters.

  7. Spatial assessment of Argentinean genetic admixture with geographical information systems.

    Science.gov (United States)

    Diaz-Lacava, Amalia; Walier, Maja; Penacino, Gustavo; Wienker, Thomas F; Baur, Max P

    2011-08-01

    In recent years there has been much attention to Argentinean population stratification. We were interested in assessing population stratification from a geographical perspective and summarizing it in form of maps. We mapped the genetic admixture of the extant male population in central and northern Argentina on the basis of forensic Y-chromosomal haplotypes. We addressed the question which group of genetically similar individuals is predominant in this area. Haplotypes containing seven Y-chromosomal short tandem repeat polymorphisms (Y-STRs), also known as microsatellites - DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393 - were constructed for 145 individuals, recruited in 10 provinces. 97 distinct haplotypes were clustered into four clusters according to molecular distances. A genetic geostatistical analysis was conducted with the open-source geographical information system GRASS GIS. For each haplotype cluster, the according frequency was spatially interpolated over the total study area. Juxtaposing the interpolation surfaces, we screened point-wisely the maximal frequency as well as the label of the respective cluster. The screening results were combined in one summary map. We repeated this procedure for the second maximal frequencies. The resulting maps subdivide the study area into continuous regions comprising one predominant group of similar haplotypes. The first summary map divides the study area into three regions and the second summary map divides the area into four regions. The results of our analysis indicate that two groups of similar European haplotypes alternatively dominate the largest extension of the Argentinean territory. A third group, including South-American haplotypes, dominates the indigenous northwestern Argentinean area. The last group, including worldwide dispersed haplotypes, preponderates in frequency in second place in central Argentina. Our findings confirm a widespread European paternal ancestry, a substantial Amerindian

  8. Real-time mapping of salt glands on the leaf surface of Cynodon dactylon L. using scanning electrochemical microscopy.

    Science.gov (United States)

    Parthasarathy, Meera; Pemaiah, Brindha; Natesan, Ravichandran; Padmavathy, Saralla R; Pachiappan, Jayaraman

    2015-02-01

    Salt glands are specialized organelles present in the leaf tissues of halophytes, which impart salt-tolerance capability to the plant species. These glands are usually identified only by their morphology using conventional staining procedures coupled with optical microscopy. In this work, we have employed scanning electrochemical microscopy to identify the salt glands not only by their morphology but also by their salt excretion behavior. Bermuda grass (Cynodon dactylon L.) species was chosen for the study as they are known to be salt-tolerant and contain salt glands on leaf surfaces. Scanning electrochemical microscopy performed in sodium chloride medium in the presence and absence of potassium ferrocyanide as redox mediator, reveals the identity of salt glands. More insight into the ion expulsion behavior of these glands was obtained by mapping lateral and vertical variations in ion concentrations using surface impedance measurements which indicated five times higher resistance over the salt glands compared to the surrounding tissues and bulk solution. The protocol could be used to understand the developmental processes in plants grown in different soil/water conditions in order to improve salt tolerance of food crops by genetic engineering and hence improve their agricultural productivity. PMID:25460612

  9. Imaging and elemental mapping of biological specimens with a dual-EDS dedicated scanning transmission electron microscope

    International Nuclear Information System (INIS)

    A dedicated analytical scanning transmission electron microscope (STEM) with dual energy dispersive spectroscopy (EDS) detectors has been designed for complementary high performance imaging as well as high sensitivity elemental analysis and mapping of biological structures. The performance of this new design, based on a Hitachi HD-2300A model, was evaluated using a variety of biological specimens. With three imaging detectors, both the surface and internal structure of cells can be examined simultaneously. The whole-cell elemental mapping, especially of heavier metal species that have low cross-section for electron energy loss spectroscopy (EELS), can be faithfully obtained. Optimization of STEM imaging conditions is applied to thick sections as well as thin sections of biological cells under low-dose conditions at room and cryogenic temperatures. Such multimodal capabilities applied to soft/biological structures usher a new era for analytical studies in biological systems. - Highlights: ► Applications of STEM in characterization of biological samples are demonstrated. ► Elemental analyses are performed by dual EDS and EELS. ► Both the surface and internal structure of cells can be studied simultaneously. ► The imaging contrast in low-dose cryo-STEM has been analyzed

  10. Imaging and elemental mapping of biological specimens with a dual-EDS dedicated scanning transmission electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Wu, J.S., E-mail: jinsong-wu@northwestern.edu [Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, Northwestern University, Evanston, IL 60208 (United States); Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208 (United States); Kim, A.M. [Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611 (United States); Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208 (United States); Bleher, R. [Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208 (United States); Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208 (United States); Myers, B.D. [Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, Northwestern University, Evanston, IL 60208 (United States); Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208 (United States); Marvin, R.G. [Department of Chemistry, Northwestern University, Evanston, IL 60208 (United States); Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208 (United States); Inada, H.; Nakamura, K. [Hitachi High-Technologies Corporation, Ibaraki 312-8504 (Japan); Zhang, X.F. [Hitachi High Technologies America, Inc., 5960 Inglewood Drive, Pleasanton, California 94588 (United States); Roth, E. [Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208 (United States); Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208 (United States); Li, S.Y. [Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, Northwestern University, Evanston, IL 60208 (United States); and others

    2013-05-15

    A dedicated analytical scanning transmission electron microscope (STEM) with dual energy dispersive spectroscopy (EDS) detectors has been designed for complementary high performance imaging as well as high sensitivity elemental analysis and mapping of biological structures. The performance of this new design, based on a Hitachi HD-2300A model, was evaluated using a variety of biological specimens. With three imaging detectors, both the surface and internal structure of cells can be examined simultaneously. The whole-cell elemental mapping, especially of heavier metal species that have low cross-section for electron energy loss spectroscopy (EELS), can be faithfully obtained. Optimization of STEM imaging conditions is applied to thick sections as well as thin sections of biological cells under low-dose conditions at room and cryogenic temperatures. Such multimodal capabilities applied to soft/biological structures usher a new era for analytical studies in biological systems. - Highlights: ► Applications of STEM in characterization of biological samples are demonstrated. ► Elemental analyses are performed by dual EDS and EELS. ► Both the surface and internal structure of cells can be studied simultaneously. ► The imaging contrast in low-dose cryo-STEM has been analyzed.

  11. Black-backed woodpecker habitat suitability mapping using conifer snag basal area estimated from airborne laser scanning

    Science.gov (United States)

    Casas Planes, Á.; Garcia, M.; Siegel, R.; Koltunov, A.; Ramirez, C.; Ustin, S.

    2015-12-01

    Occupancy and habitat suitability models for snag-dependent wildlife species are commonly defined as a function of snag basal area. Although critical for predicting or assessing habitat suitability, spatially distributed estimates of snag basal area are not generally available across landscapes at spatial scales relevant for conservation planning. This study evaluates the use of airborne laser scanning (ALS) to 1) identify individual conifer snags and map their basal area across a recently burned forest, and 2) map habitat suitability for a wildlife species known to be dependent on snag basal area, specifically the black-backed woodpecker (Picoides arcticus). This study focuses on the Rim Fire, a megafire that took place in 2013 in the Sierra Nevada Mountains of California, creating large patches of medium- and high-severity burned forest. We use forest inventory plots, single-tree ALS-derived metrics and Gaussian processes classification and regression to identify conifer snags and estimate their stem diameter and basal area. Then, we use the results to map habitat suitability for the black-backed woodpecker using thresholds for conifer basal area from a previously published habitat suitability model. Local maxima detection and watershed segmentation algorithms resulted in 75% detection of trees with stem diameter larger than 30 cm. Snags are identified with an overall accuracy of 91.8 % and conifer snags are identified with an overall accuracy of 84.8 %. Finally, Gaussian process regression reliably estimated stem diameter (R2 = 0.8) using height and crown area. This work provides a fast and efficient methodology to characterize the extent of a burned forest at the tree level and a critical tool for early wildlife assessment in post-fire forest management and biodiversity conservation.

  12. Elements-admixtures of fluorite. Research technique

    International Nuclear Information System (INIS)

    Present article is devoted to elements-admixtures of fluorite and research techniques used. As a material for researches the mono mineral samples of fluorite of various geologic deposits and ores were used. The determination of sodium and potassium was conducted by means of flame photometry. Strontium, uranium, thorium, lead and rubidium were determined by means of quantitative X-ray spectroscopic analysis. The barium analysis was conducted by means of quantitative method. The manganese analysis was conducted by means of electron paramagnetic resonance.

  13. Forest biomass estimation by the use of airborne laser scanning data and in situ FieldMap measurements in a spruce forest stand

    OpenAIRE

    Petrila, Marius; Apostol, Bogdan; Lorenţ, Adrian; Gancz, Vladimir; Silaghi, Diana

    2013-01-01

    The main purpose of this study is to analyze the possibility of stand biomass evaluation based on biometric measurements from airborne laser scanning data in a spruce forest test area. Data fusion of airborne laser scanning, and aerial orthoimagery (0.5 m spatial resolution), as well as the use of FieldMap equipment in the measurement of reference data in sampling plots makes it possible to estimate different stand parameters. An important stage of height evaluation in the spruce test a...

  14. Shrinkage and cracking behavior of high performance concretes containing chemical admixtures

    Institute of Scientific and Technical Information of China (English)

    亓萌; 李宗津; 马保国

    2002-01-01

    Modern concretes often incorporate several chemical admixtures to alter the properties of fresh or hardened concrete. In this work, the influences of three types of chemical admixtures, calcium nitrite inhibitor (CNI), retarder (D-17) and superplasticizer (W-19) on free shrinkage and restrained shrinkage cracking of high performance concrete were experimentally investigated. The test results showed that, with the same water to binder ratio (0.4), mixtures containing D-17 of 0.25 percent or higher ratio of W-19 (2.76 percent) all exhibited a reduction in free shrinkage and shrinkage cracking width. However, the incorporations of various ratios of CNI into mixtures led to an increase in free shrinkage and shrinkage cracking width as compared to control mixture. In order to study the influence of CNI, the microstructure of concrete mixture containing CNI were investigated by Mercury Intrusion Porosimetry as well as Scanning Electronic Microscopy(SEM) technique.

  15. The origin of early age expansions induced in cementitious materials containing shrinkage reducing admixtures

    International Nuclear Information System (INIS)

    Studies on the early-age shrinkage behavior of cement pastes, mortars, and concretes containing shrinkage reducing admixtures (SRAs) have indicated these mixtures frequently exhibit an expansion shortly after setting. While the magnitude of the expansion has been noted to be a function of the chemistry of the cement and the admixture dosage; the cause of the expansion is not clearly understood. This investigation uses measurements of autogenous deformation, X-ray diffraction, pore solution analysis, thermogravimetry, and scanning electron microscopy to study the early-age properties and describe the mechanism of the expansion in OPC pastes made with and without SRA. The composition of the pore solution indicates that the presence of the SRA increases the portlandite oversaturation level in solution which can result in higher crystallization stresses which could lead to an expansion. This observation is supported by deformation calculations for the systems examined.

  16. Admixture, Population Structure, and F-Statistics.

    Science.gov (United States)

    Peter, Benjamin M

    2016-04-01

    Many questions about human genetic history can be addressed by examining the patterns of shared genetic variation between sets of populations. A useful methodological framework for this purpose isF-statistics that measure shared genetic drift between sets of two, three, and four populations and can be used to test simple and complex hypotheses about admixture between populations. This article provides context from phylogenetic and population genetic theory. I review howF-statistics can be interpreted as branch lengths or paths and derive new interpretations, using coalescent theory. I further show that the admixture tests can be interpreted as testing general properties of phylogenies, allowing extension of some ideas applications to arbitrary phylogenetic trees. The new results are used to investigate the behavior of the statistics under different models of population structure and show how population substructure complicates inference. The results lead to simplified estimators in many cases, and I recommend to replaceF3with the average number of pairwise differences for estimating population divergence. PMID:26857625

  17. Corrosion mapping in ducts using the automated ultrasonic technique C-Scan - correlation with results given by pig inspection; Mapeamento de corrosao em dutos atraves da tecnica ultrassonica C-Scan

    Energy Technology Data Exchange (ETDEWEB)

    Feres Filho, Pedro; Moura, Nestor Carlos de [Physical Acoustics South America (PASA), Sao Paulo, SP (Brazil)

    2005-07-01

    In-service inspection has received diverse contributions from technologies and documents with the objective of maximizing equipment availability and minimizing inadequate repairs. Amongst the available technologies, there are the automated ultrasound tests, in the B and C-scan versions. This paper describes an evaluation methodology based on the correlation between the test techniques of instrumented electromagnetic PIG and automated ultrasound, both applied with the purpose of detecting and mapping areas with corrosion in pipes for oil transport. The main objective of the application of the C-scan methodology, in this case, was the measuring and detailing of the corroded area, thus providing an adequate maintenance plan through the substitution or installation of a double gutter. The result demonstrates the correlation between the measurements taken by the PIG and the sizing of the regions done using the C-scan method, consisting of the length, width and thickness values in the points affected by the corrosion. (author)

  18. Mapping tree health using airborne laser scans and hyperspectral imagery: a case study for a floodplain eucalypt forest

    Science.gov (United States)

    Shendryk, Iurii; Tulbure, Mirela; Broich, Mark; McGrath, Andrew; Alexandrov, Sergey; Keith, David

    2016-04-01

    Airborne laser scanning (ALS) and hyperspectral imaging (HSI) are two complementary remote sensing technologies that provide comprehensive structural and spectral characteristics of forests over large areas. In this study we developed two algorithms: one for individual tree delineation utilizing ALS and the other utilizing ALS and HSI to characterize health of delineated trees in a structurally complex floodplain eucalypt forest. We conducted experiments in the largest eucalypt, river red gum forest in the world, located in the south-east of Australia that experienced severe dieback over the past six decades. For detection of individual trees from ALS we developed a novel bottom-up approach based on Euclidean distance clustering to detect tree trunks and random walks segmentation to further delineate tree crowns. Overall, our algorithm was able to detect 67% of tree trunks with diameter larger than 13 cm. We assessed the accuracy of tree delineations in terms of crown height and width, with correct delineation of 68% of tree crowns. The increase in ALS point density from ~12 to ~24 points/m2 resulted in tree trunk detection and crown delineation increase of 11% and 13%, respectively. Trees with incorrectly delineated crowns were generally attributed to areas with high tree density along water courses. The accurate delineation of trees allowed us to classify the health of this forest using machine learning and field-measured tree crown dieback and transparency ratios, which were good predictors of tree health in this forest. ALS and HSI derived indices were used as predictor variables to train and test object-oriented random forest classifier. Returned pulse width, intensity and density related ALS indices were the most important predictors in the tree health classifications. At the forest level in terms of tree crown dieback, 77% of trees were classified as healthy, 14% as declining and 9% as dying or dead with 81% mapping accuracy. Similarly, in terms of tree

  19. Mapping microclimate pH distribution inside protein-encapsulated PLGA microspheres using confocal laser scanning microscopy.

    Science.gov (United States)

    Liu, Yajun; Schwendeman, Steven P

    2012-05-01

    The pH in the aqueous pores of poly(lactide-co-glycolide) (PLGA) matrix, also referred to as microclimate pH (μpH), is often uncontrolled, ranging from highly acidic to neutral pH range. The μpH distribution inside protein-encapsulated PLGA microspheres was quantitatively evaluated using confocal laser scanning microscopy. The fluorescent response of Lysosensor yellow/blue dextran used to map μpH in PLGA was influenced by the presence of encapsulated protein. The nonprotonated form of pyridyl group on the fluorescence probe at neutral pH was responsible for the interference, which was dependent on the type and concentration of protein. A method for correction of this interference based on estimating protein concentration inside the microspheres was established and validated. After correction of the influence, the μpH distribution kinetics inside microspheres was evaluated for different PLGA 50/50 microsphere formulations under physiological conditions for 4 weeks. Generally, the μpH acidity increased with the progression of incubation time. The coincorporation of poorly soluble base, magnesium carbonate, in the microspheres prolonged the appearance of detectable acidity for up to 3 weeks. Co-addition of an acetate buffer was able to control the μpH over a slightly acidic range (around pH 4.7) after two week incubation. Microspheres prepared from a lower polymer concentration exhibited a higher μpH, likely owing to reduced diffusional resistance to acidic degradation products. The stability of protein was enhanced by addition of MgCO(3), acetate buffer, or by reduced polymer concentration in the preparation, as evidenced by more soluble protein recovered after incubation. Hence, the μpH imaging technique developed can be employed in the future for optimization of formulation strategies for controlling μpH and stabilizing encapsulated proteins. PMID:22428586

  20. Multiway admixture deconvolution using phased or unphased ancestral panels.

    Science.gov (United States)

    Churchhouse, Claire; Marchini, Jonathan

    2013-01-01

    We describe a novel method for inferring the local ancestry of admixed individuals from dense genome-wide single nucleotide polymorphism data. The method, called MULTIMIX, allows multiple source populations, models population linkage disequilibrium between markers and is applicable to datasets in which the sample and source populations are either phased or unphased. The model is based upon a hidden Markov model of switches in ancestry between consecutive windows of loci. We model the observed haplotypes within each window using a multivariate normal distribution with parameters estimated from the ancestral panels. We present three methods to fit the model-Markov chain Monte Carlo sampling, the Expectation Maximization algorithm, and a Classification Expectation Maximization algorithm. The performance of our method on individuals simulated to be admixed with European and West African ancestry shows it to be comparable to HAPMIX, the ancestry calls of the two methods agreeing at 99.26% of loci across the three parameter groups. In addition to it being faster than HAPMIX, it is also found to perform well over a range of extent of admixture in a simulation involving three ancestral populations. In an analysis of real data, we estimate the contribution of European, West African and Native American ancestry to each locus in the Mexican samples of HapMap, giving estimates of ancestral proportions that are consistent with those previously reported. PMID:23136122

  1. High Precision and Fast Functional Mapping of Cortical Circuitry Through a Novel Combination of Voltage Sensitive Dye Imaging and Laser Scanning Photostimulation

    OpenAIRE

    Xu, Xiangmin; Olivas, Nicholas D.; Levi, Rafael; Ikrar, Taruna; Nenadic, Zoran

    2010-01-01

    The development of modern neuroscience tools is critical for deciphering brain circuit organization and function. An important aspect for technical development is to enhance each technique's advantages and compensate for limitations. We developed a high-precision and fast functional mapping technique in brain slices that incorporates the spatial precision of activation that can be achieved by laser-scanning photostimulation with rapid and high-temporal resolution assessment of evoked network ...

  2. Large-scale and high-resolution 3-D cave mapping by terrestrial laser scanning: a case study of the Domica Cave, Slovakia

    Directory of Open Access Journals (Sweden)

    Michal Gallay

    2015-09-01

    Full Text Available Mapping and modelling the complicated geometry of caves is a challenging task that has traditionally been undertaken by tacheometric surveying methods. These methods are excellent for capturing the general shape of a cave system but they are not suitable for high-speed, high-resolution mapping of complex surfaces found in this environment. Terrestrial laser scanning (TLS technologies can acquire millions of points represented by 3-D coordinates, at very high spatial densities on complex multifaceted surfaces within minutes. In the last few years, advances in measurement speed, reduction in size / cost and increased portability of this technology has revolutionised the collection of 3-D data. This paper discusses the methodological framework and the advantages / disadvantages of adopting terrestrial laser scanning to rapidly map a complex cave system on the example of the Domica Cave in Slovakia. This cave originated in the largest karst region in the West Carpathians. The collected data set or ‘point cloud’ contains over 11.9 billion measured points, captured in 5 days from 327 individual scanning positions. The dataset represents almost 1600 m of the cave passages. Semi-automatic registration of these scans was carried out using reference spheres placed in each scene and this method archived an overall registration error of 2.24 mm (RMSE. Transformation of the final registered point cloud from its local coordinate system to the national cartographic system was achieved with total accuracy of 21 mm (RMSE. This very detailed data set was used to create a 3-D cave surface model needed for volumetric analyses. In the future, it will be used for spatial analyses or simulating the interaction of surface and subsurface processes contributing to the development of the cave system on the basis of a 3-D GIS platform.

  3. SU-E-J-113: Effects of Deformable Registration On First-Order Texture Maps Calculated From Thoracic Lung CT Scans

    International Nuclear Information System (INIS)

    Purpose: To determine the stability of eight first-order texture features following the deformable registration of serial computed tomography (CT) scans. Methods: CT scans at two different time points from 10 patients deemed to have no lung abnormalities by a radiologist were collected. Following lung segmentation using an in-house program, texture maps were calculated from 32×32-pixel regions of interest centered at every pixel in the lungs. The texture feature value of the ROI was assigned to the center pixel of the ROI in the corresponding location of the texture map. Pixels in the square ROI not contained within the segmented lung were not included in the calculation. To quantify the agreement between ROI texture features in corresponding pixels of the baseline and follow-up texture maps, the Fraunhofer MEVIS EMPIRE10 deformable registration algorithm was used to register the baseline and follow-up scans. Bland-Altman analysis was used to compare registered scan pairs by computing normalized bias (nBias), defined as the feature value change normalized to the mean feature value, and normalized range of agreement (nRoA), defined as the range spanned by the 95% limits of agreement normalized to the mean feature value. Results: Each patient’s scans contained between 6.8–15.4 million ROIs. All of the first-order features investigated were found to have an nBias value less than 0.04% and an nRoA less than 19%, indicating that the variability introduced by deformable registration was low. Conclusion: The eight first-order features investigated were found to be registration stable. Changes in CT texture maps could allow for temporal-spatial evaluation of the evolution of lung abnormalities relating to a variety of diseases on a patient-by-patient basis. SGA and HA receives royalties and licensing fees through the University of Chicago for computer-aided diagnosis technology. Research reported in this publication was supported by the National Institute Of General

  4. SU-E-J-113: Effects of Deformable Registration On First-Order Texture Maps Calculated From Thoracic Lung CT Scans

    Energy Technology Data Exchange (ETDEWEB)

    Smith, C; Cunliffe, A; Al-Hallaq, H; Armato, S [The University of Chicago, Chicago, IL (United States)

    2015-06-15

    Purpose: To determine the stability of eight first-order texture features following the deformable registration of serial computed tomography (CT) scans. Methods: CT scans at two different time points from 10 patients deemed to have no lung abnormalities by a radiologist were collected. Following lung segmentation using an in-house program, texture maps were calculated from 32×32-pixel regions of interest centered at every pixel in the lungs. The texture feature value of the ROI was assigned to the center pixel of the ROI in the corresponding location of the texture map. Pixels in the square ROI not contained within the segmented lung were not included in the calculation. To quantify the agreement between ROI texture features in corresponding pixels of the baseline and follow-up texture maps, the Fraunhofer MEVIS EMPIRE10 deformable registration algorithm was used to register the baseline and follow-up scans. Bland-Altman analysis was used to compare registered scan pairs by computing normalized bias (nBias), defined as the feature value change normalized to the mean feature value, and normalized range of agreement (nRoA), defined as the range spanned by the 95% limits of agreement normalized to the mean feature value. Results: Each patient’s scans contained between 6.8–15.4 million ROIs. All of the first-order features investigated were found to have an nBias value less than 0.04% and an nRoA less than 19%, indicating that the variability introduced by deformable registration was low. Conclusion: The eight first-order features investigated were found to be registration stable. Changes in CT texture maps could allow for temporal-spatial evaluation of the evolution of lung abnormalities relating to a variety of diseases on a patient-by-patient basis. SGA and HA receives royalties and licensing fees through the University of Chicago for computer-aided diagnosis technology. Research reported in this publication was supported by the National Institute Of General

  5. Development, Calibration and Evaluation of a Portable and Direct Georeferenced Laser Scanning System for Kinematic 3D Mapping

    Science.gov (United States)

    Heinz, Erik; Eling, Christian; Wieland, Markus; Klingbeil, Lasse; Kuhlmann, Heiner

    2015-12-01

    In recent years, kinematic laser scanning has become increasingly popular because it offers many benefits compared to static laser scanning. The advantages include both saving of time in the georeferencing and a more favorable scanning geometry. Often mobile laser scanning systems are installed on wheeled platforms, which may not reach all parts of the object. Hence, there is an interest in the development of portable systems, which remain operational even in inaccessible areas. The development of such a portable laser scanning system is presented in this paper. It consists of a lightweight direct georeferencing unit for the position and attitude determination and a small low-cost 2D laser scanner. This setup provides advantages over existing portable systems that employ heavy and expensive 3D laser scanners in a profiling mode. A special emphasis is placed on the system calibration, i. e. the determination of the transformation between the coordinate frames of the direct georeferencing unit and the 2D laser scanner. To this end, a calibration field is used, which consists of differently orientated georeferenced planar surfaces, leading to estimates for the lever arms and boresight angles with an accuracy of mm and one-tenth of a degree. Finally, point clouds of the mobile laser scanning system are compared with georeferenced point clouds of a high-precision 3D laser scanner. Accordingly, the accuracy of the system is in the order of cm to dm. This is in good agreement with the expected accuracy, which has been derived from the error propagation of previously estimated variance components.

  6. Mapping an on-chip terahertz antenna by a scanning near-field probe and a fixed field-effect transistor

    Institute of Scientific and Technical Information of China (English)

    吕利; 孙建东; RogerA.Lewis; 孙云飞; 吴东岷; 蔡勇; 秦华

    2015-01-01

    In the terahertz (THz) regime, the active region for a solid-state detector usually needs to be implemented accurately in the near-field region of an on-chip antenna. Mapping of the near-field strength could allow for rapid verification and optimization of new antenna/detector designs. Here, we report a proof-of-concept experiment in which the field mapping is realized by a scanning metallic probe and a fixed AlGaN/GaN field-effect transistor. Experiment results agree well with the electromagnetic-wave simulations. The results also suggest a field-effect THz detector combined with a probe tip could serve as a high sensitivity THz near-field sensor.

  7. Mapping an on-chip terahertz antenna by a scanning near-field probe and a fixed field-effect transistor

    International Nuclear Information System (INIS)

    In the terahertz (THz) regime, the active region for a solid-state detector usually needs to be implemented accurately in the near-field region of an on-chip antenna. Mapping of the near-field strength could allow for rapid verification and optimization of new antenna/detector designs. Here, we report a proof-of-concept experiment in which the field mapping is realized by a scanning metallic probe and a fixed AlGaN/GaN field-effect transistor. Experiment results agree well with the electromagnetic-wave simulations. The results also suggest a field-effect THz detector combined with a probe tip could serve as a high sensitivity THz near-field sensor. (paper)

  8. Learning with Admixture: Modeling, Optimization, and Applications in Population Genetics

    DEFF Research Database (Denmark)

    Cheng, Jade Yu

    2016-01-01

    including population splits, effective population sizes, gene flow, etc. Since joining the CoalHMM development team in 2014, I have mainly contributed in two directions: 1) improving optimizations through heuristic-based evolutionary algorithms and 2) modeling of historical admixture events. Ohana, meaning...... data. Ohana's admixture module is based on classical structure modeling but uses new optimization subroutines through quadratic programming, which outperform the current state-of-the-art software in both speed and accuracy. Ohana presents a new method for phylogenetic tree inference using Gaussian...

  9. Variation in genetic admixture and population structure among Latinos: the Los Angeles Latino eye study (LALES

    Directory of Open Access Journals (Sweden)

    Le Marchand Loic

    2009-11-01

    Full Text Available Abstract Background Population structure and admixture have strong confounding effects on genetic association studies. Discordant frequencies for age-related macular degeneration (AMD risk alleles and for AMD incidence and prevalence rates are reported across different ethnic groups. We examined the genomic ancestry characterizing 538 Latinos drawn from the Los Angeles Latino Eye Study [LALES] as part of an ongoing AMD-association study. To help assess the degree of Native American ancestry inherited by Latino populations we sampled 25 Mayans and 5 Mexican Indians collected through Coriell's Institute. Levels of European, Asian, and African descent in Latinos were inferred through the USC Multiethnic Panel (USC MEP, formed from a sample from the Multiethnic Cohort (MEC study, the Yoruba African samples from HapMap II, the Singapore Chinese Health Study, and a prospective cohort from Shanghai, China. A total of 233 ancestry informative markers were genotyped for 538 LALES Latinos, 30 Native Americans, and 355 USC MEP individuals (African Americans, Japanese, Chinese, European Americans, Latinos, and Native Hawaiians. Sensitivity of ancestry estimates to relative sample size was considered. Results We detected strong evidence for recent population admixture in LALES Latinos. Gradients of increasing Native American background and of correspondingly decreasing European ancestry were observed as a function of birth origin from North to South. The strongest excess of homozygosity, a reflection of recent population admixture, was observed in non-US born Latinos that recently populated the US. A set of 42 SNPs especially informative for distinguishing between Native Americans and Europeans were identified. Conclusion These findings reflect the historic migration patterns of Native Americans and suggest that while the 'Latino' label is used to categorize the entire population, there exists a strong degree of heterogeneity within that population, and that

  10. Research and manufacture about high-activity small admixture in sprayed concrete

    Energy Technology Data Exchange (ETDEWEB)

    Fan, W.; Zhang, Z.; Zheng, Y. [Jiaozuo Institute of Technology, Jiaozuo (China)

    2000-04-01

    Two types of high-activity small admixture are researched and produced by using industrial wastes: (1) F-type high-activity small admixture; (2) K-type high-activity small admixture. If these high-activity small admixtures were used to replace 30 percent of cement, the strength of the sprayed concrete may be enhanced by about 20 percent. 1 ref., 7 tabs.

  11. Use of pentapeptide-insertion scanning mutagenesis for functional mapping of the plum pox virus helper component proteinase suppressor of gene silencing.

    Science.gov (United States)

    Varrelmann, Mark; Maiss, Edgar; Pilot, Ruth; Palkovics, Laszlo

    2007-03-01

    Helper component proteinase (HC-Pro) of Plum pox virus is a multifunctional potyvirus protein that has been examined intensively. In addition to its involvement in aphid transmission, genome amplification and long-distance movement, it is also one of the better-studied plant virus suppressors of RNA silencing. The first systematic analysis using pentapeptide-insertion scanning mutagenesis of the silencing suppression function of a potyvirus HC-Pro is presented here. Sixty-three in-frame insertion mutants, each containing five extra amino acids inserted randomly within the HC-Pro protein, were analysed for their ability to suppress transgene-induced RNA silencing using Agrobacterium infiltration in transgenic Nicotiana benthamiana plants expressing green fluorescent protein. A functional map was obtained, consisting of clearly defined regions with different classes of silencing-suppression activity (wild-type, restricted and disabled). This map confirmed that the N-terminal part of the protein, which is indispensable for aphid transmission, is dispensable for silencing suppression and supports the involvement of the central region in silencing suppression, in addition to its role in maintenance of genome amplification and synergism with other viruses. Moreover, evidence is provided that the C-terminal part of the protein, previously known to be necessary mainly for proteolytic activity, also participates in silencing suppression. Pentapeptide-insertion scanning mutagenesis has been shown to be a fast and powerful tool to functionally characterize plant virus proteins. PMID:17325375

  12. 3D mapping of geological contacts by coupling Aerial Laser Scanning, Gigapixel photography and open access pictures

    Science.gov (United States)

    Nguyen, Liliane; Guerin, Antoine; Abellán, Antonio; Carrea, Dario; Derron, Marc-Henri; Jaboyedoff, Michel

    2015-04-01

    Multiple sources of geological data exist nowadays, most of them are in 2D (e.g. geological maps, geological panoramic sketch), and only a few are in 3D (e.g. block diagram). One of the current challenges in geological mapping consists not only in providing a more consistent 3D data, but also in pursuing a gathering and a harmonisation of the geological information in order to obtain a more consistent interpretations of the 3D geological models. New remote sensing techniques have significantly improved the representation of three-dimensional surfaces during the last decade, especially for steep and inaccessible rockcliffs. Therefore, we present an exploratory study aiming to find a reliable method for carrying out a three-dimensional mapping of geological contacts using a High Resolution Digital Elevation Model (HRDEM) with a 1 meter cell size. To this end, we selected the "Scex Rouge Mountain" as pilot study area. This outcrop, which is located in the Diablerets Massif (Vaud, Swiss Alps), has the particularity to present very distinguishable folded geological boundaries on its Southern face. The Southern slope belongs to the Wildhorn nappe, which is mainly composed of sedimentary rocks. The top-layer is composed of siliceous limestones, the well-visible fold layer is the "Pygurus layer" and consist of sandy limestone. Finally the bottom-layer includes marly schist and clayey limestones. At first, different sources of information has been draped on the HRDEM of the Scex Rouge Mountain, including not only classical geological maps (1:25 000) but also different sources of imagery (e.g. gigapixel panoramas, open access images, etc.). In a second step, several three-dimensional polylines have been drawn following the geological limit on each drapped HRDEM. Then we investigated the accuracy of 2D classical geological maps by comparing these geological limits with the drawn 3D polylines. Furthermore, in order to evaluate the accuracy of the method, a ground truth needs

  13. Mutation Scanning Using MUT-MAP, a High-Throughput, Microfluidic Chip-Based, Multi-Analyte Panel

    OpenAIRE

    Patel, Rajesh; Tsan, Alison; Tam, Rachel; Desai, Rupal; Schoenbrunner, Nancy; Myers, Thomas W.; Bauer, Keith; Smith, Edward; Raja, Rajiv

    2012-01-01

    Targeted anticancer therapies rely on the identification of patient subgroups most likely to respond to treatment. Predictive biomarkers play a key role in patient selection, while diagnostic and prognostic biomarkers expand our understanding of tumor biology, suggest treatment combinations, and facilitate discovery of novel drug targets. We have developed a high-throughput microfluidics method for mutation detection (MUT-MAP, mutation multi-analyte panel) based on TaqMan or allele-specific P...

  14. Biodiversity Mapping via Natura 2000 Conservation Status and Ebv Assessment Using Airborne Laser Scanning in Alkali Grasslands

    Science.gov (United States)

    Zlinszky, A.; Deák, B.; Kania, A.; Schroiff, A.; Pfeifer, N.

    2016-06-01

    Biodiversity is an ecological concept, which essentially involves a complex sum of several indicators. One widely accepted such set of indicators is prescribed for habitat conservation status assessment within Natura 2000, a continental-scale conservation programme of the European Union. Essential Biodiversity Variables are a set of indicators designed to be relevant for biodiversity and suitable for global-scale operational monitoring. Here we revisit a study of Natura 2000 conservation status mapping via airbone LIDAR that develops individual remote sensing-derived proxies for every parameter required by the Natura 2000 manual, from the perspective of developing regional-scale Essential Biodiversity Variables. Based on leaf-on and leaf-off point clouds (10 pt/m2) collected in an alkali grassland area, a set of data products were calculated at 0.5 ×0.5 m resolution. These represent various aspects of radiometric and geometric texture. A Random Forest machine learning classifier was developed to create fuzzy vegetation maps of classes of interest based on these data products. In the next step, either classification results or LIDAR data products were selected as proxies for individual Natura 2000 conservation status variables, and fine-tuned based on field references. These proxies showed adequate performance and were summarized to deliver Natura 2000 conservation status with 80% overall accuracy compared to field references. This study draws attention to the potential of LIDAR for regional-scale Essential Biodiversity variables, and also holds implications for global-scale mapping. These are (i) the use of sensor data products together with habitat-level classification, (ii) the utility of seasonal data, including for non-seasonal variables such as grassland canopy structure, and (iii) the potential of fuzzy mapping-derived class probabilities as proxies for species presence and absence.

  15. North African populations carry the signature of admixture with Neandertals

    DEFF Research Database (Denmark)

    Sánchez-Quinto, Federico; Botigué, Laura R; Civit, Sergi;

    2012-01-01

    One of the main findings derived from the analysis of the Neandertal genome was the evidence for admixture between Neandertals and non-African modern humans. An alternative scenario is that the ancestral population of non-Africans was closer to Neandertals than to Africans because of ancient popu...

  16. Mapping asthma-associated variants in admixed populations

    OpenAIRE

    Mersha, Tesfaye B.

    2015-01-01

    Admixed populations arise when two or more previously isolated populations interbreed. Mapping asthma susceptibility loci in an admixed population using admixture mapping (AM) involves screening the genome of individuals of mixed ancestry for chromosomal regions that have a higher frequency of alleles from a parental population with higher asthma risk as compared with parental population with lower asthma risk. AM takes advantage of the admixture created in populations of mixed ancestry to id...

  17. Mapping asthma-associated variants in admixed populations

    OpenAIRE

    Mersha, Tesfaye B.

    2015-01-01

    Admixed populations arise when two or more previously isolated populations start interbreeding. Mapping asthma susceptibility loci in an admixed population using admixture mapping (AM) involves screening the genome of individuals of mixed ancestry for chromosomal regions that have a higher frequency of alleles compared to the parental population with higher asthma risk. AM takes advantage of the admixture created in populations of mixed ancestry by searching for association between the ancest...

  18. Effect of Some Admixtures on the Hydration of Silica Fume and Hydrated Lime

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The effects of sodium salt of naphthalene formaldehyde sulfonic acid and stearic acid on the hydration of silica fume and Ca(0H)2 have been investigated. The hydration was carried out at 60℃ and W/S ratio of 4 for various time intervals namely, 1, 3, 7 and 28 days and in the presence of 0.2% and 5% superplasticizer and stearic acid. The results of the hydration kinetics show that both admixtures accelerate the hydration reaction of silica fume and calcium hydroxide during the first 7 days. Whereas, after 28 days hydration there is no significant effect. Generally, most of free calcium hydroxide seems to be consumed after 28 days. In addition, the phase composition as well as the microstructure of the formed hydrates was examined by using X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM) respectively.

  19. Scanning micro-Hall probe mapping of magnetic flux distributions and current densities in YBa{sub 2}Cu{sub 3}O{sub 7}

    Energy Technology Data Exchange (ETDEWEB)

    Xing, W.; Heinrich, B. [Simon Fraser Univ., British Columbia (Canada); Zhou, H. [CTF Systems, Inc., British Columbia (Canada)] [and others

    1994-12-31

    Mapping of the magnetic flux density B{sub z} (perpendicular to the film plane) for a YBa{sub 2}Cu{sub 3}O{sub 7} thin-film sample was carried out using a scanning micro-Hall probe. The sheet magnetization and sheet current densities were calculated from the B{sub z} distributions. From the known sheet magnetization, the tangential (B{sub x,y}) and normal components of the flux density B were calculated in the vicinity of the film. It was found that the sheet current density was mostly determined by 2B{sub x,y}/d, where d is the film thickness. The evolution of flux penetration as a function of applied field will be shown.

  20. Ancestry inference in complex admixtures via variable-length Markov chain linkage models.

    Science.gov (United States)

    Rodriguez, Jesse M; Bercovici, Sivan; Elmore, Megan; Batzoglou, Serafim

    2013-03-01

    Inferring the ancestral origin of chromosomal segments in admixed individuals is key for genetic applications, ranging from analyzing population demographics and history, to mapping disease genes. Previous methods addressed ancestry inference by using either weak models of linkage disequilibrium, or large models that make explicit use of ancestral haplotypes. In this paper we introduce ALLOY, an efficient method that incorporates generalized, but highly expressive, linkage disequilibrium models. ALLOY applies a factorial hidden Markov model to capture the parallel process producing the maternal and paternal admixed haplotypes, and models the background linkage disequilibrium in the ancestral populations via an inhomogeneous variable-length Markov chain. We test ALLOY in a broad range of scenarios ranging from recent to ancient admixtures with up to four ancestral populations. We show that ALLOY outperforms the previous state of the art, and is robust to uncertainties in model parameters. PMID:23421795

  1. Detection of prostate cancer by integration of line-scan diffusion, T2-mapping and T2-weighted magnetic resonance imaging; a multichannel statistical classifier.

    Science.gov (United States)

    Chan, Ian; Wells, William; Mulkern, Robert V; Haker, Steven; Zhang, Jianqing; Zou, Kelly H; Maier, Stephan E; Tempany, Clare M C

    2003-09-01

    A multichannel statistical classifier for detecting prostate cancer was developed and validated by combining information from three different magnetic resonance (MR) methodologies: T2-weighted, T2-mapping, and line scan diffusion imaging (LSDI). From these MR sequences, four different sets of image intensities were obtained: T2-weighted (T2W) from T2-weighted imaging, Apparent Diffusion Coefficient (ADC) from LSDI, and proton density (PD) and T2 (T2 Map) from T2-mapping imaging. Manually segmented tumor labels from a radiologist, which were validated by biopsy results, served as tumor "ground truth." Textural features were extracted from the images using co-occurrence matrix (CM) and discrete cosine transform (DCT). Anatomical location of voxels was described by a cylindrical coordinate system. A statistical jack-knife approach was used to evaluate our classifiers. Single-channel maximum likelihood (ML) classifiers were based on 1 of the 4 basic image intensities. Our multichannel classifiers: support vector machine (SVM) and Fisher linear discriminant (FLD), utilized five different sets of derived features. Each classifier generated a summary statistical map that indicated tumor likelihood in the peripheral zone (PZ) of the prostate gland. To assess classifier accuracy, the average areas under the receiver operator characteristic (ROC) curves over all subjects were compared. Our best FLD classifier achieved an average ROC area of 0.839(+/-0.064), and our best SVM classifier achieved an average ROC area of 0.761(+/-0.043). The T2W ML classifier, our best single-channel classifier, only achieved an average ROC area of 0.599(+/-0.146). Compared to the best single-channel ML classifier, our best multichannel FLD and SVM classifiers have statistically superior ROC performance (P=0.0003 and 0.0017, respectively) from pairwise two-sided t-test. By integrating the information from multiple images and capturing the textural and anatomical features in tumor areas, summary

  2. Detection of prostate cancer by integration of line-scan diffusion, T2-mapping and T2-weighted magnetic resonance imaging; a multichannel statistical classifier

    International Nuclear Information System (INIS)

    A multichannel statistical classifier for detecting prostate cancer was developed and validated by combining information from three different magnetic resonance (MR) methodologies: T2-weighted, T2-mapping, and line scan diffusion imaging (LSDI). From these MR sequences, four different sets of image intensities were obtained: T2-weighted (T2W) from T2-weighted imaging, Apparent Diffusion Coefficient (ADC) from LSDI, and proton density (PD) and T2 (T2 Map) from T2-mapping imaging. Manually segmented tumor labels from a radiologist, which were validated by biopsy results, served as tumor ''ground truth.'' Textural features were extracted from the images using co-occurrence matrix (CM) and discrete cosine transform (DCT). Anatomical location of voxels was described by a cylindrical coordinate system. A statistical jack-knife approach was used to evaluate our classifiers. Single-channel maximum likelihood (ML) classifiers were based on 1 of the 4 basic image intensities. Our multichannel classifiers: support vector machine (SVM) and Fisher linear discriminant (FLD), utilized five different sets of derived features. Each classifier generated a summary statistical map that indicated tumor likelihood in the peripheral zone (PZ) of the prostate gland. To assess classifier accuracy, the average areas under the receiver operator characteristic (ROC) curves over all subjects were compared. Our best FLD classifier achieved an average ROC area of 0.839(±0.064), and our best SVM classifier achieved an average ROC area of 0.761(±0.043). The T2W ML classifier, our best single-channel classifier, only achieved an average ROC area of 0.599(±0.146). Compared to the best single-channel ML classifier, our best multichannel FLD and SVM classifiers have statistically superior ROC performance (P=0.0003 and 0.0017, respectively) from pairwise two-sided t-test. By integrating the information from multiple images and capturing the textural and anatomical features in tumor areas, summary

  3. Venous admixture in COPD: Pathophysiology and therapeutic approaches

    OpenAIRE

    Cooper, CB; Celli, B

    2008-01-01

    Chronic obstructive and interstitial lung diseases impair pulmonary gas exchange leading to wasted ventilation (alveolar dead space) and wasted perfusion (venous admixture). These two fundamental types of abnormality represent opposite ends of the spectrum of ventilation-perfusion mismatch with V̇/Q̇ ratios of infinity and zero. Treatment approaches that improve airway function, reduce air trapping and hyperinflation have received much attention and might be successful at ameliorating the pro...

  4. Extensive Admixture and Selective Pressure Across the Sahel Belt

    Czech Academy of Sciences Publication Activity Database

    Triska, P.; Soares, P.; Patin, E.; Fernandes, V.; Černý, Viktor; Pereira, L.

    2015-01-01

    Roč. 7, č. 12 (2015), s. 3484-3495. ISSN 1759-6653 R&D Projects: GA ČR GA13-37998S Institutional support: RVO:67985912 Keywords : genome-wide diversity * admixture * selection * Sahel Subject RIV: AC - Archeology, Anthropology, Ethnology Impact factor: 4.229, year: 2014 http://gbe.oxfordjournals.org/content/7/12/3484.full.pdf+html

  5. Mutation scanning using MUT-MAP, a high-throughput, microfluidic chip-based, multi-analyte panel.

    Directory of Open Access Journals (Sweden)

    Rajesh Patel

    Full Text Available Targeted anticancer therapies rely on the identification of patient subgroups most likely to respond to treatment. Predictive biomarkers play a key role in patient selection, while diagnostic and prognostic biomarkers expand our understanding of tumor biology, suggest treatment combinations, and facilitate discovery of novel drug targets. We have developed a high-throughput microfluidics method for mutation detection (MUT-MAP, mutation multi-analyte panel based on TaqMan or allele-specific PCR (AS-PCR assays. We analyzed a set of 71 mutations across six genes of therapeutic interest. The six-gene mutation panel was designed to detect the most common mutations in the EGFR, KRAS, PIK3CA, NRAS, BRAF, and AKT1 oncogenes. The DNA was preamplified using custom-designed primer sets before the TaqMan/AS-PCR assays were carried out using the Biomark microfluidics system (Fluidigm; South San Francisco, CA. A cross-reactivity analysis enabled the generation of a robust automated mutation-calling algorithm which was then validated in a series of 51 cell lines and 33 FFPE clinical samples. All detected mutations were confirmed by other means. Sample input titrations confirmed the assay sensitivity with as little as 2 ng gDNA, and demonstrated excellent inter- and intra-chip reproducibility. Parallel analysis of 92 clinical trial samples was carried out using 2-100 ng genomic DNA (gDNA, allowing the simultaneous detection of multiple mutations. DNA prepared from both fresh frozen and formalin-fixed, paraffin-embedded (FFPE samples were used, and the analysis was routinely completed in 2-3 days: traditional assays require 0.5-1 µg high-quality DNA, and take significantly longer to analyze. This assay can detect a wide range of mutations in therapeutically relevant genes from very small amounts of sample DNA. As such, the mutation assay developed is a valuable tool for high-throughput biomarker discovery and validation in personalized medicine and cancer drug

  6. Mirror matter admixtures in K_L to mu^+ mu^-

    CERN Document Server

    Sánchez-Colón, G; Sanchez-Colon, Gabriel; Garcia, Augusto

    2006-01-01

    Our previous analysis on the contributions of mirror matter admixtures in ordinary hadrons to K_L to gamma gamma is extended to study the relevance of such contributions to the K_L to mu^+ mu^- rare decay. The mixing angle of the admixtures previously determined to describe the enhancement phenomenon in two body non-leptonic decays of strange hadrons is used, along with recent results for the description of the strong and electromagnetic interaction parts of the transition amplitudes. We find that these admixtures give a significant contribution with a small SU(3) breaking of only 2.8%, we also find a value of \\sim -17.9^{\\circ} for the eta-eta' mixing angle consistent with some of its determinations in the literature and a preferred negative value around -16 for the local counter-term contribution chi_1 + chi_2 consistent with the existence of a unique counter-term assuming lepton universality. We conclude that those mixings may be relevant in low energy physics and should not be ignored.

  7. Mapping out Map Libraries

    Directory of Open Access Journals (Sweden)

    Ferjan Ormeling

    2008-09-01

    Full Text Available Discussing the requirements for map data quality, map users and their library/archives environment, the paper focuses on the metadata the user would need for a correct and efficient interpretation of the map data. For such a correct interpretation, knowledge of the rules and guidelines according to which the topographers/cartographers work (such as the kind of data categories to be collected, and the degree to which these rules and guidelines were indeed followed are essential. This is not only valid for the old maps stored in our libraries and archives, but perhaps even more so for the new digital files as the format in which we now have to access our geospatial data. As this would be too much to ask from map librarians/curators, some sort of web 2.0 environment is sought where comments about data quality, completeness and up-to-dateness from knowledgeable map users regarding the specific maps or map series studied can be collected and tagged to scanned versions of these maps on the web. In order not to be subject to the same disadvantages as Wikipedia, where the ‘communis opinio’ rather than scholarship, seems to be decisive, some checking by map curators of this tagged map use information would still be needed. Cooperation between map curators and the International Cartographic Association ( ICA map and spatial data use commission to this end is suggested.

  8. Laser-scanning astrocyte mapping reveals increased glutamate-responsive domain size and disrupted maturation of glutamate uptake following neonatal cortical freeze-lesion

    Directory of Open Access Journals (Sweden)

    Mortiz eArmbruster

    2014-09-01

    Full Text Available Astrocytic uptake of glutamate shapes extracellular neurotransmitter dynamics, receptor activation, and synaptogenesis. During development, glutamate transport becomes more robust. How neonatal brain insult affects the functional maturation of glutamate transport remains unanswered. Neonatal brain insult can lead to developmental delays, cognitive losses, and epilepsy; the disruption of glutamate transport is known to cause changes in synaptogenesis, receptor activation, and seizure. Using the neonatal freeze-lesion (FL model, we have investigated how insult affects the maturation of astrocytic glutamate transport. As lesioning occurs on the day of birth, a time when astrocytes are still functionally immature, this model is ideal for identifying changes in astrocyte maturation following insult. Reactive astrocytosis, astrocyte proliferation, and in vitro hyperexcitability are known to occur in this model. To probe astrocyte glutamate transport with better spatial precision we have developed a novel technique, Laser Scanning Astrocyte Mapping (LSAM, which combines glutamate transport current (TC recording from astrocytes with laser scanning glutamate photolysis. LSAM allows us to identify the area from which a single astrocyte can transport glutamate and to quantify spatial heterogeneity in the rate of glutamate clearance kinetics within that domain. Using LSAM, we report that cortical astrocytes have an increased glutamate-responsive area following FL and that TCs have faster decay times in distal, as compared to proximal processes. Furthermore, the developmental shift from GLAST- to GLT-1-dominated clearance is disrupted following FL. These findings introduce a novel method to probe astrocyte glutamate uptake and show that neonatal cortical FL disrupts the functional maturation of cortical astrocytes.

  9. Practical handling of AIO admixtures – Guidelines on Parenteral Nutrition, Chapter 10

    OpenAIRE

    Stanga, Z; Franken, C.; Mühlebach, S; Working group for developing the guidelines for parenteral nutrition of The German Association for Nutritional Medicine

    2009-01-01

    All-in-one admixtures (AIO-admixtures) provide safe, effective and low-risk PN (parenteral nutrition) for practically all indications and applications. Water, energy (carbohydrates and lipids), amino acids, vitamins and trace elements are infused together with PN either as industrially-manufactured AIO admixtures provided as two- or three-chamber bags (shelf life usually more than 12 months) completed with electrolytes and micronutrients where appropriate or as individually compounded ready-t...

  10. Practical handling of AIO admixtures - Guidelines on Parenteral Nutrition, Chapter 10

    OpenAIRE

    Mühlebach, S; Franken, C.; Stanga, Z; Working group for developing the guidelines for parenteral nutrition of The German Association for Nutritional Medicine

    2009-01-01

    All-in-one admixtures (AIO-admixtures) provide safe, effective and low-risk PN (parenteral nutrition) for practically all indications and applications. Water, energy (carbohydrates and lipids), amino acids, vitamins and trace elements are infused together with PN either as industrially-manufactured AIO admixtures provided as two- or three-chamber bags (shelf life usually more than 12 months) completed with electrolytes and micronutrients where appropriate or as individually compounded ready-t...

  11. Polycarboxylate superplasticiser admixtures: effect on hydration, microstructure and rheological behaviour in cement pastes

    OpenAIRE

    Puertas, F.; Santos, H.; Palacios, M.; Martínez-Ramírez, Sagrario

    2005-01-01

    A study was conducted on the effect of a polycarboxylate (PC) admixture on the mechanical, mineralogical, microstructural and rheological behaviour of Portland cement pastes. It was observed that the presence of PC admixture retards the initial cement hydration reactions, although this effect may be offset by possible increased diffusion in later stages. Additionally, the PC admixtures produce a few alterations in the structure and composition of the formed C–S–H gel. The addition of 1% PC...

  12. The Influence of Admixtures on the Technological Properties of Fresh Concrete Mixture

    OpenAIRE

    Albertas KLOVAS; Daukšys, Mindaugas

    2015-01-01

    In this research superplasticizing (SP), air voids removing (AVR), viscosity modifying (VM) and air entraining admixtures (AE) were used. The dosage of admixtures was chosen from minimum to maximum values recommended by the manufacturers. To sum up, 7 concrete mixture compositions with SP, 6 with AVR and 6 with VM and the last 6 with AE admixture were prepared. Water and cement ratio for all the compositions was kept at the same value. According to the results obtained, the usage of SP admixt...

  13. Experimental Study on Durability Improvement of Fly Ash Concrete with Durability Improving Admixture

    OpenAIRE

    Quan, Hong-zhu; Kasami, Hideo

    2014-01-01

    In order to improve the durability of fly ash concrete, a series of experimental studies are carried out, where durability improving admixture is used to reduce drying shrinkage and improve freezing-thawing resistance. The effects of durability improving admixture, air content, water-binder ratio, and fly ash replacement ratio on the performance of fly ash concrete are discussed in this paper. The results show that by using durability improving admixture in nonair-entraining fly ash concrete,...

  14. Practical handling of AIO admixtures – Guidelines on Parenteral Nutrition, Chapter 10

    Directory of Open Access Journals (Sweden)

    Stanga, Z.

    2009-11-01

    Full Text Available All-in-one admixtures (AIO-admixtures provide safe, effective and low-risk PN (parenteral nutrition for practically all indications and applications. Water, energy (carbohydrates and lipids, amino acids, vitamins and trace elements are infused together with PN either as industrially-manufactured AIO admixtures provided as two- or three-chamber bags (shelf life usually more than 12 months completed with electrolytes and micronutrients where appropriate or as individually compounded ready-to-use AIO admixtures (compounding, usually prepared by a pharmacy on either a daily or weekly basis and stored at 2–8°C. Physico-chemical and microbial stability of an AIO admixture is essential for the safety and effectiveness of patient-specific PN, and its assurance requires specialist pharmaceutical knowledge. The stability should be documented for an application period of 24 (–48 hours. It is advisable to offer a limited selection of different PN regimes in each hospital. For reasons of drug and medication safety, PN admixtures prepared for individual patients must be correctly labelled and specifications for storage conditions must also be followed during transport. Monitoring is required where applicable. Micronutrients are usually administered separately to AIO admixtures. In case compatibility and stability have been well documented trace elements and/or combination preparations including water-soluble or water-soluble/fat soluble vitamin supplements can be added to PN admixtures under strict aseptic conditions. AIO admixtures are usually not used as vehicles for drugs (incompatibilities.

  15. Effect of Anti-freezing Admixtures on Alkali-silica Reaction in Mortars

    Institute of Scientific and Technical Information of China (English)

    LIU Junzhe; LI Yushun; LV Lihua

    2005-01-01

    The influence of anti-freezing admixture on the alkali aggregate reaction in mortar was analyzed with accelerated methods. It is confirmed that the addition of sodium salt ingredients of anti-freezing admixture accelerates the alkali silica reaction to some extent, whereas calcium salt ingredient of anti-freezing admixture reduces the expansion of alkali silica reaction caused by high alkali cement. It is found that the addition of the fly ash considerably suppresses the expansion of alkali silica reaction induced by the anti-freezing admixtures.

  16. Integration of UAV-Based Photogrammetry and Terrestrial Laser Scanning for the Three-Dimensional Mapping and Monitoring of Open-Pit Mine Areas

    Directory of Open Access Journals (Sweden)

    Xiaohua Tong

    2015-05-01

    Full Text Available This paper presents a practical framework for the integration of unmanned aerial vehicle (UAV based photogrammetry and terrestrial laser scanning (TLS with application to open-pit mine areas, which includes UAV image and TLS point cloud acquisition, image and cloud point processing and integration, object-oriented classification and three-dimensional (3D mapping and monitoring of open-pit mine areas. The proposed framework was tested in three open-pit mine areas in southwestern China. (1 With respect to extracting the conjugate points of the stereo pair of UAV images and those points between TLS point clouds and UAV images, some feature points were first extracted by the scale-invariant feature transform (SIFT operator and the outliers were identified and therefore eliminated by the RANdom SAmple Consensus (RANSAC approach; (2 With respect to improving the accuracy of geo-positioning based on UAV imagery, the ground control points (GCPs surveyed from global positioning systems (GPS and the feature points extracted from TLS were integrated in the bundle adjustment, and three scenarios were designed and compared; (3 With respect to monitoring and mapping the mine areas for land reclamation, an object-based image analysis approach was used for the classification of the accuracy improved UAV ortho-image. The experimental results show that by introduction of TLS derived point clouds as GCPs, the accuracy of geo-positioning based on UAV imagery can be improved. At the same time, the accuracy of geo-positioning based on GCPs form the TLS derived point clouds is close to that based on GCPs from the GPS survey. The results also show that the TLS derived point clouds can be used as GCPs in areas such as in mountainous or high-risk environments where it is difficult to conduct a GPS survey. The proposed framework achieved a decimeter-level accuracy for the generated digital surface model (DSM and digital orthophoto map (DOM, and an overall accuracy of 90

  17. The influence of shrinkage reducing admixtures on plastic shrinkage

    Directory of Open Access Journals (Sweden)

    Mora, J.

    2003-12-01

    Full Text Available Shrinkage reducing admixtures (SRAs are viable alternatives for reducing plastic shrinkage cracking in concrete. The objective of the present paper is to study early age plastic shrinkage in restrained concrete elements, where three different SRAs have been used. The influence of the admixture is analyzed through the following measurements: capillary pressure, evaporation, temperature evolution, crack evolution and settlement. The tests for studying the cracking and deformation were made on two different configurations (i.e., restrained prisms with reduced cross-section and restrained panel, in a wind tunnel, with controlled wind temperature and velocity. The conclusions obtained indicate the viability of the use of this type of admixture and the usefulness of the test methods.

    Los aditivos reductores de retracción (SRAs se plantean, hoy en día, como una alternativa viable para reducir la fisuración por retracción plástica. El objetivo del presente artículo es conocer mejor y predecir el comportamiento a primeras edades de la retracción plástica en elementos estructurales coaccionados, a los que se les ha añadido diversos aditivos reductores de retracción (tres tipos diferentes. Esta influencia se analiza a través de las siguientes propiedades: presión capilar, evaporación, evolución de temperaturas, evolución de fisuración, y deformaciones verticales de asentamiento. Los ensayos para estudiar la fisuración y las deformaciones se han realizado sobre diferentes configuraciones (prisma restringido con estrangulamiento y panel restringido, en un túnel de viento, con temperaturas y velocidades de viento controladas. Las conclusiones obtenidas señalan la viabilidad del empleo de este tipo de aditivos y la bondad de los métodos experimentales utilizados.

  18. Mirror matter admixtures in K_S to gamma gamma

    CERN Document Server

    Sánchez-Colón, G; Sanchez-Colon, Gabriel; Garcia, Augusto

    2006-01-01

    The latest measurement of the K_S to gamma gamma branching ratio clearly shows an enhancement over the current theoretical prediction. As in other K and B meson decays, this invites to consider the possibility of the contribution of new physics. We study a particular form of the latter, which may be referred to as manifest mirror symmetry. The experimental data are described using previously determined values for the mixing angles of the admixtures of mirror matter in ordinary hadrons and by assuming that for pi^0, eta, eta', the mirror decay amplitudes have the same magnitudes as their ordinary counterparts.

  19. Symmetry limit properties of decay amplitudes with mirror matter admixtures

    CERN Document Server

    Sánchez-Colón, G; Sanchez-Colon, Gabriel; Garcia, Augusto

    2006-01-01

    We extend our previous analysis on the symmetry limit properties of non-leptonic and weak radiative decay amplitudes of hyperons in a scheme of mirror matter admixtures in physical hadrons to include the two-body non-leptonic decays of $\\Omega^-$ and the two photon and two pion decays of kaons. We show that the so-called parity-conserving amplitudes predicted for all the decays vanish in the strong flavor SU(3) symmetry limit. We also establish the specific conditions under which the corresponding so-called parity-violating amplitudes vanish in the same limit.

  20. Whistler Solitons in Plasma with Anisotropic Hot Electron Admixture

    Science.gov (United States)

    Khazanov, G. V.; Krivorutsky, E. N.; Gallagher, D. L.

    1999-01-01

    The longitudinal and transverse modulation instability of whistler waves in plasma, with a small admixture of hot anisotropic electrons, is discussed. If the hot particles temperature anisotropy is positive, it is found that, in such plasma, longitudinal perturbations can lead to soliton formation for frequencies forbidden in cold plasma. The soliton is enriched by hot particles. The frequency region unstable to transverse modulation in cold plasma in the presence of hot electrons is divided by stable domains. For both cases the role of hot electrons is more significant for whistlers with smaller frequencies.

  1. Effect of polycarboxylate admixture structure on cement paste rheology

    OpenAIRE

    Aranda, M. A. G.; De la Torre, A.G.; Puertas, F.; Palacios, M.; Alonso, M M

    2007-01-01

    The purpose of the present study was to analyze the effect of the structural differences in four polycarboxylate and polyether admixtures on the rheological properties of cement pastes with different chemical and mineralogical compositions and different active additions (CEM I 42.5 R, CEM I 52.5 R, CEM I 52.5 N/SR, CEM II/AV 42.5R, CEM II/B-L 32.5 R, CEM III/B 32.5R, BL I 52.5R and CAC – European standard EN 197-1:2000). The results of the minislump test concurred with the variations ob...

  2. Influence of chloride admixtures on cement matrix durability

    International Nuclear Information System (INIS)

    The influence of various inorganic salts, as chloride admixtures to Portland cement, on the mechanical properties and the durability of the matrix has been studied. The salts used in this study are chromium, nickel and cadmium chlorides. Improved compressive strength values are obtained which have been correlated to the stable metal hydroxide formation in high pH environment. Under static water conditions at 500C, hydrolyzed chloride ions exhibit adverse effects on the matrix durability through rapid release of calcium as calcium chloride in the initial period of leaching. On the contrary, enhanced matrix durability is obtained on long term leaching in the case of cement containing chromium chloride

  3. Incorporation of Mineral Admixtures in Sustainable High Performance Concrete

    Directory of Open Access Journals (Sweden)

    Nima Farzadnia

    2011-07-01

    Full Text Available Concrete is a widely used construction material around the world, and its properties have been undergoing changes through technological advancement. Numerous types of concrete have been developed to enhance the different properties of concrete. So far, this development can be divided into four stages. The earliest is the traditional normal strength concrete which is composed of only four constituent materials, which are cement, water, fine and coarse aggregates. With a fast population growth and a higher demand for housing and infrastructure, accompanied by recent developments in civil engineering, such as high-rise buildings and long-span bridges, higher compressive strength concrete was needed. At the beginning, reducing the water-cement ratio was the easiest way to achieve the high compressive strength. Thereafter, the fifth ingredient, a water reducing agent or super plasticizer, was indispensable. However, sometimes the compressive strength was not as important as some other properties, such as low permeability, durability and workability. Thus, high performance concrete was proposed and widely studied at the end of the last century. Currently, high-performance concrete is used in massive volumes due to its technical and economic advantages. Such materials are characterized by improved mechanical and durability properties resulting from the use of chemical and mineral admixtures as well as specialized production processes. This paper reviews the incorporation of mineral admixtures in binary, ternary and quaternary blended mortars in concrete.

  4. Physicochemical compatibility of nebulizable drug admixtures containing colistimethate and tobramycin.

    Science.gov (United States)

    Wollstadt, A; Krämer, I; Kamin, W

    2013-09-01

    Inhalation therapy with nebulizable antibiotic drugs is a mainstay in treating Pseudomonas aeruginosa infections in cystic fibrosis patients. The combination of tobramycin and colistin was found to be superior to monotherapy in killing P. aeruginosa in biofilms. The simultaneous inhalation of tobramycin and colistin might be an option to increase the compliance of patients. The objective of this in-vitro study was to determine whether admixtures of inhalation solutions containing colistin methanesulfonate (CMS) and tobramycin are physicochemically compatible. Physical compatibility was determined by measuring pH and osmolality. Chemical compatibility was determined by testing the antibiotic activity of the mixtures by the pharmacopoeial microbiological assay and comparing the results to those of standard solutions. Samples were analyzed immediately after mixing and after 24 h. Values of pH and osmolality remained unchanged and in physiologically acceptable ranges. Neither for colistin methanesulfonate (CMS) nor for tobramycin losses of antibiotic potency were registered at any time. Admixtures of nebulizer solutions containing CMS and tobramycin were shown to be physicochemically compatible. Further investigations are needed to determine whether drug delivery is affected by mixing the nebulizer solutions to ensure that simultaneous inhalation is recommendable. PMID:24147342

  5. Fly Ash Admixture and its Influence on Alitic Type Cement Concrete Permeability

    OpenAIRE

    Rujanu, Mircea; Rujanu, Bogdan

    2012-01-01

    Experimental and theoretical studies pointed that adding fly ash in concrete composition, could favour its impermeability characteristic improvement. It is known, also, that fly ash admixture achieves cement dosage reduction, so that concrete will be cheaper, and in this conditions it is important to analyse fly ash admixture influence on impermeability degree, too.

  6. Genome-wide Ancestry Patterns in Rapanui Suggest Pre-European Admixture with Native Americans

    DEFF Research Database (Denmark)

    Moreno-Mayar, J. Víctor; Rasmussen, Simon; Seguin-Orlando, Andaine;

    2014-01-01

    . We found a mostly Polynesian ancestry among Rapanui and detected genome-wide patterns consistent with Native American and European admixture. By considering the distribution of local ancestry tracts of eight unrelated Rapanui, we found statistical support for Native American admixture dating to AD...

  7. The application study of polycarboxylates water-reducing admixture in passenger dedicated line engineering%The application study of polycarboxylates water-reducing admixture in passenger dedicated line engineering

    Institute of Scientific and Technical Information of China (English)

    Huang Zhijiu

    2012-01-01

    Polycarboxylate water-reducing admixture possesses the capability which could meet with the comprehensive performance of high performance concrete used in passenger dedicated line engineering. The problems of polycarboxylates water-reducing admixtures existed in the engineering application of were analyzed. At present the key for polycarboxylates application was to settle the compatibility between the water-reducing admixture and the cement and to keep the quality retention of this admixture.

  8. Admixture analysis and stocking impact assessment in brown trout ( Salmo trutta ), estimated with incomplete baseline data

    DEFF Research Database (Denmark)

    Hansen, Michael Møller; Eg Nielsen, Einar; Bekkevold, Dorte;

    2001-01-01

    Studies of genetic interactions between wild and domesticated fish are often hampered by unavailability of samples from wild populations prior to population admixture. We assessed the utility of a new Bayesian method, which can estimate individual admixture coefficients even with data missing from...... the populations contributing to admixture. We applied the method to analyse the genetic contribution of domesticated brown trout (Salmo trutta) in samples of anadromous trout from two stocked populations with no genetic data available before stocking. Further, we estimated population level admixture proportions...... by the mean of individual admixture coefficients. This method proved more informative than a multidimensional scaling analysis of individual-based genetic distances and assignment tests. The results showed almost complete absence of stocked, domesticated trout in samples of trout from the rivers. Consequently...

  9. EFFECTS OF CHEMICAL ADMIXTURES ON SPECIALITIES OF HARDENED CONCRETE USED IN READY CONCRETE PRODUCTION IN ESKİŞEHİR

    OpenAIRE

    TOPÇU, İlker Bekir; IŞIKDAĞ, Burak; Özgür TATAR

    2006-01-01

    In this study polls were taken from different ready mixed concrete firms in Eskişehir. Chemical admixtures used in concrete production were investigated according to the polls, and some information about chemical admixtures was obtained. Compressive strengths of concrete specimens manufactured by ready mixed concrete firms were evaluated, and results were investigated due to different types and proportions of admixtures used in concrete. Chemical admixtures were compared to each other at the ...

  10. Identification of admixture for pelletization and strength enhancement of sintered coal pond ash aggregate through statistically designed experiments

    International Nuclear Information System (INIS)

    Highlights: • Sintered aggregate using pond ash from lignite and bituminous coal source. • Identification of admixtures and its dosage through design of experiments. • Clay, bentonite and kaolinite as binders enhance the strength of aggregate. • Use of calcium hydroxide with clay binder enhanced pelletization efficiency. • Use of borax with clay binders enhanced the strength of aggregate. - Abstract: Statistically designed experiments using Response Surface Methodology have been undertaken to identify the parameters influencing manufacturing process and properties of aggregate using coal pond ash (generated from bituminous and lignite coal sources). Based on the preliminary studies, Ca(OH)2 and borax have been identified as pelletization and strength enhancing admixture respectively. Pelletization efficiency of bituminous and lignite pond ash increased with an increase in binder and Ca(OH)2 dosage to 20–98% and 50–98% respectively, with proportionate quantity of water. Sintering has been used as a hardening method with temperature range of 900 °C and 1100 °C for a duration range of 45–120 min. Phase composition and sintered microstructure of aggregate has been reported using X-ray diffraction and scanning electron microscopy respectively. The ten percent fines value of aggregate with clay binder was 5.5 tonne as against a value of 4.5 tonne with aggregate with bentonite binder. Among the binders studied, bentonite resulted in high volume utilization of pond ash, i.e. up to 88%

  11. Nuclear Scans

    Science.gov (United States)

    Nuclear scans use radioactive substances to see structures and functions inside your body. They use a special ... images. Most scans take 20 to 45 minutes. Nuclear scans can help doctors diagnose many conditions, including ...

  12. Used cooking oil as a green chemical admixture in concrete

    International Nuclear Information System (INIS)

    According to National Statistics Approximately 1.35 billion gallons of used oil are generated yearly. With the increasing of the concrete usage, a more cost effective and economic new type of admixtures may give positive impacts on the Malaysian construction building as well as worldwide concrete usage. To objective of this is study is to investigate the effect of used cooking oil in terms of slump test, compressive strength test and rebound hammer. By adding the used cooking oil to the concrete, it increases the slump value from 4% to 72%. And the compressive strength have an increment from 1% to 16.8%. The used cooking oil obtains the optimum contribution to the concrete mix proportion of containing used cooking oil of 1.50% from the cement content. The result of used cooking oil from experimental program of slump value and compressive strength proved that used cooking oil have positive effects on replacement of commercially available superplasticizer.

  13. Used cooking oil as a green chemical admixture in concrete

    Science.gov (United States)

    Salmia, B.; Che Muda, Zakaria; Ashraful Alam, Md; Sidek, L. M.; Hidayah, B.

    2013-06-01

    According to National Statistics Approximately 1.35 billion gallons of used oil are generated yearly. With the increasing of the concrete usage, a more cost effective and economic new type of admixtures may give positive impacts on the Malaysian construction building as well as worldwide concrete usage. To objective of this is study is to investigate the effect of used cooking oil in terms of slump test, compressive strength test and rebound hammer. By adding the used cooking oil to the concrete, it increases the slump value from 4% to 72%. And the compressive strength have an increment from 1% to 16.8%. The used cooking oil obtains the optimum contribution to the concrete mix proportion of containing used cooking oil of 1.50% from the cement content. The result of used cooking oil from experimental program of slump value and compressive strength proved that used cooking oil have positive effects on replacement of commercially available superplasticizer.

  14. Techniques and methods of characterization of admixtures for the concrete

    Directory of Open Access Journals (Sweden)

    Palacios, M.

    2003-03-01

    Full Text Available Admixtures are defined as those products that are incorporated in the moment of the process of mixture of the concrete in a quantity not bigger than 5 by mass of the cement %, with relationship to the cement content in the concrete, with object of modifying the properties of the mixture in .state fresh and/or hardened. The behaviour of the admixtures depends on its chemical and ionic composition, the organic functional groups present, and the structure of the polymer and the distribution of molecular weight of the different polymers. In the present work the techniques and methods of characterization physical-chemistry, chemistry and ionic, structural, as well as of the polymers that constitute this admixtures, are described. A lot of techniques have been employed like: ionic chromatography, ultraviolet-visible spectroscopy (UV-VIS, Fourier transform infrared spectroscopy (FTIR, Fourier transform Raman spectroscopy (FT-Raman, nuclear magnetic resonance spectroscopy (1H-RMN and 13C-RMN, gel permeation chromatography (GPC. Two commercial admixtures have been selected to carry out this characterization, a superplastificant based on policarboxilates, and a reducer of the shrinkage based on polipropilenglycol.

    RESUMEN Se definen los aditivos como aquellos productos que son incorporados en el momento del amasado del hormigón en una cantidad no mayor del 5% en masa, con relación al contenido de cemento en el hormigón, con objeto de modificar las propiedades de la mezcla en estado fresco y/o endurecido. El comportamiento de los aditivos depende de su composición química e iónica, de los grupos funcionales orgánicos presentes, de la estructura del polímero y de la distribución de pesos moleculares de los diferentes polímeros que lo constituyen. En el presente trabajo se describen diferentes técnicas y métodos de caracterización físico-química, química e iónica, estructural, así como de los polímeros que

  15. A factorial design study on the physical stability of 3-in-1 admixtures.

    Science.gov (United States)

    Li, L C; Sampogna, T P

    1993-11-01

    The effects of dextrose concentration, the compounding method, and storage conditions, on the physical stability of 3-in-1 admixtures were investigated using a 2n factorial design. The main effect of these three variables on the weight percent of oil globules larger than 5 microns (by HIAC) was found to be statistically significant. However, the effects of interaction amongst these variables, except the two-way interaction between dextrose concentration and storage conditions, were found to be statistically insignificant. A higher dextrose concentration was shown to enhance the physical stability of the admixtures, while low-temperature storage (three days at 5 degrees C) was more favourable for maintaining the physical stability of the admixtures with a low dextrose concentration. Although sequential pumping produced admixtures with a slightly lower final weight percentage of larger oil globules (> 5 microns), the method of compounding has the least impact on the physical stability of the admixtures in comparison with the other two variables evaluated in this study. The storage of the admixtures at room temperature for one day was shown to have a greater adverse effect on admixtures with a low dextrose concentration. PMID:7908042

  16. Finding new solutions in pediatric parenteral admixtures: how to improve quality and to deal with shortages

    Directory of Open Access Journals (Sweden)

    Dorota Watrobska-Swietlikowska

    2014-07-01

    Full Text Available Introduction: Pediatric parenteral nutrition enables normal growth even of preterm infants. Those children require, however, tailored parenteral nutrition and the creation of such can be challenging due to the risk of instability and shortages. Objective: Prototypical parenteral admixtures were created using different calcium salts (organic and inorganic and different lipid emulsions and tested for stability. 36 of parenteral admixtures containing two types of calcium salts: chloride or gluconolactobionate and different lipid emulsions (SMOFlipid® or Lipofundin MCT/LCT® were under investigation. Methods: Preliminary admixtures were prepared in two-chamber bags whereas lipid emulsions were placed separately in the second chamber. Pre-admixtures were stored for up to 21 days at +4ºC. Contents of the two chambers were combined at t = 0 or after 21 days of storage. Physical analysis of completed admixtures (visual inspection, microscopic observation, pH measurement and determination of the size distribution of oily droplets was carried out after 21 days of the storage. Stability of lipid, commercial emulsions stored in ethylene vinyl acetate (EVA bags for 42 days was also studied. Results: Irrespectively of the time of storage of preadmixtures and type of calcium salt and different lipid emulsions among 36 total parenteral admixtures only one showed signs of destabilization after preparation and one was unstable when stored for longer than 14 days. All other formulations were qualified to be stable during the study. All investigated commercial lipid emulsions were physically stable in EVA bags even when stored at room temperature. Conclusion: The study proved that it was possible to store pre-admixture in EVA bags for 21 days at 4ºC as well as that CAN (critical aggregation number and CaxP (the products of multiplication of calcium and phosphate ions concentration should not be used as reliable indicators of admixture physical stability. No

  17. EFFECTS OF CHEMICAL ADMIXTURES ON SPECIALITIES OF HARDENED CONCRETE USED IN READY CONCRETE PRODUCTION IN ESKİŞEHİR

    Directory of Open Access Journals (Sweden)

    İlker Bekir TOPÇU

    2006-01-01

    Full Text Available In this study polls were taken from different ready mixed concrete firms in Eskişehir. Chemical admixtures used in concrete production were investigated according to the polls, and some information about chemical admixtures was obtained. Compressive strengths of concrete specimens manufactured by ready mixed concrete firms were evaluated, and results were investigated due to different types and proportions of admixtures used in concrete. Chemical admixtures were compared to each other at the end of the investigation, and the results showed, chemical admixtures gain concrete different characteristics according to various environmental conditions. The past investigations showed that the differences between chemical admixtures were most occurred owing to environmental conditions (season, temperature etc., and chemical admixtures were classified according to seasons by users.

  18. Advanced Network Scanning

    Directory of Open Access Journals (Sweden)

    Ashiqur Rahman

    2016-07-01

    Full Text Available Network scanning is à procedure for identifying active hosts on a network, either for the purpose of attacking them or for network security assessment. Scanning procedures, such as ping sweeps and port scans, return information about which IP addresses map to live hosts that are active on the Internet and what services they offer. Another scanning method, inverse mapping, returns information about what IP addresses do not map to live hosts; this enables an attacker to make assumptions about viable addresses. Scanning is one of three components of intelligence gathering for an attacker. In the foot printing phase, the attacker creates a profile of the target organization, with information such as its domain name system (DNS and e-mail servers, and its IP address range. Most of this information is available online. In the scanning phase, the attacker finds information about the specific IP addresses that can be accessed over the Internet, their operating systems, the system architecture, and the services running on each computer. In the enumeration phase, the attacker gathers information such as network user and group names, routing tables, and Simple Network Management Protocol (SNMP data

  19. Effect of polycarboxylate admixture structure on cement paste rheology

    Directory of Open Access Journals (Sweden)

    Aranda, M. A. G.

    2007-06-01

    Full Text Available The purpose of the present study was to analyze the effect of the structural differences in four polycarboxylate and polyether admixtures on the rheological properties of cement pastes with different chemical and mineralogical compositions and different active additions (CEM I 42.5 R, CEM I 52.5 R, CEM I 52.5 N/SR, CEM II/AV 42.5R, CEM II/B-L 32.5 R, CEM III/B 32.5R, BL I 52.5R and CAC – European standard EN 197-1:2000. The results of the minislump test concurred with the variations observed in the values of the rheological parameters (shear stress and plastic viscosity. The structural characteristic of the admixtures found to play the most prominent role in their fluidizing effect was the proportion of carboxylate (CG and polyether (EG group components. In cements characteristics such as fineness and the C3A/calcium sulphate and C3S/C3A ratios were also observed to be essential to admixture effectiveness. In this regard, the rheological parameters varied most widely in CEM I 52.5N/SR pastes and least in BL I 52.5R cement pastes. Of the additioned cements, the CEM III/B 32.5R pastes, which contained granulated blast furnace slag, showed the highest rises in flowability. Finally, the fluidizing effect of polycarboxylate superplasticizers was much more intense in calcium aluminate cements, although flowability declined rapidly in this material.El objetivo de este trabajo ha sido estudiar el efecto de las diferencias estructurales de cuatro aditivos basados en policarboxilatos y poliéteres sobre las propiedades reológicas de pastas de cemento con diferente composición química, mineralógica y con distintas adiciones activas (CEM I 42,5 R, CEM I 52,5 R, CEM I 52,5 N/SR, CEM II/AV 42,5R, CEM II/ B-L 32,5 R, CEM III/B 32,5R, BL I 52,5R y CAC - Norma EN 197-1:2000. Los resultados obtenidos sobre la fluidez de la pasta en el ensayo del “Minislump” coinciden con la evolución de los valores de los parámetros reológicos (esfuerzo de

  20. Stability of admixture containing morphine sulfate, bupivacaine hydrochloride, and clonidine hydrochloride in an implantable infusion system.

    Science.gov (United States)

    Classen, Ashley M; Wimbish, Gary H; Kupiec, Thomas C

    2004-12-01

    Intrathecal infusion is often performed using drug combinations. This study was conducted to evaluate the stability of the admixture of morphine sulfate, bupivacaine hydrochloride, and clonidine hydrochloride when used in an implantable pump under simulated clinical use conditions. SynchroMed implantable pumps were filled with an admixture and incubated at 37 degrees C for a period of 90 days. Drug admixture stored in glass vials at 4 degrees C and at 37 degrees C served as controls. Samples which included pump reservoir and catheter delivered aliquots were collected every 30 days and analyzed for drug concentrations using a stability-indicating HPLC method. All drugs contained in the admixture were stable and the original concentrations remained greater than 96%. Over 90 days, and with the pump at the simulated body temperature of 37 degrees C, there were no evident heat catalyzed or device catalyzed reactions. PMID:15589086

  1. Admixture enhanced controlled low-strength material for direct underwater injection with minimal cross-contamination

    International Nuclear Information System (INIS)

    Commercially available admixtures have been developed for placing traditional concrete products under water. This paper evaluates adapting anti-washout admixture (AWA) and high range water reducing admixture (HRWRA) products to enhance controlled low-strength materials (CLSMs) for underwater placement. A simple experimental scale model (based on dynamic and geometric similitude) of typical grout pump emplacement equipment has been developed to determine the percentage of cementing material washed out. The objective of this study was to identify proportions of admixtures and underwater CLSM emplacement procedures which would minimize the cross-contamination of the displaced water while maintaining the advantages of CLSM. Since the displaced water from radioactively contaminated systems must be subsequently treated prior to release to the environment, the amount of cross-contamination is important for cases in which cementing material could form hard sludges in a water treatment facility and contaminate the in-place CLSM stabilization medium

  2. A Genome-Wide Search for Greek and Jewish Admixture in the Kashmiri Population

    Science.gov (United States)

    Tashi, Tsewang; Lorenzo, Felipe Ramos; Feusier, Julie Ellen; Mir, Hyder

    2016-01-01

    The Kashmiri population is an ethno-linguistic group that resides in the Kashmir Valley in northern India. A longstanding hypothesis is that this population derives ancestry from Jewish and/or Greek sources. There is historical and archaeological evidence of ancient Greek presence in India and Kashmir. Further, some historical accounts suggest ancient Hebrew ancestry as well. To date, it has not been determined whether signatures of Greek or Jewish admixture can be detected in the Kashmiri population. Using genome-wide genotyping and admixture detection methods, we determined there are no significant or substantial signs of Greek or Jewish admixture in modern-day Kashmiris. The ancestry of Kashmiri Tibetans was also determined, which showed signs of admixture with populations from northern India and west Eurasia. These results contribute to our understanding of the existing population structure in northern India and its surrounding geographical areas. PMID:27490348

  3. $\\Sigma^-$ admixture in the $^{10}_\\Lambda$Li hypernucleus with a repulsive $\\Sigma$-nucleus potential

    CERN Document Server

    Lanskoy, D E

    2013-01-01

    $\\Sigma^-$ hyperon component of the $^{10}_\\Lambda$Li wave function is studied. The $\\Sigma^-$ admixture is vital for production of neutron-rich $\\Lambda$ hypernuclei via mesonic beams. We use a simplified shell model wave function for the $\\Lambda$ channel and calculate the $\\Sigma^-$ admixture directly from coupled equations. Probability of the $\\Sigma^-$ admixture for realistic repulsive $\\Sigma^-$-nucleus potentials is less by several times than that for attractive potentials and does not exceed $0.1\\%$. We conclude that the cross sections of the $^{10}\\mbox{B}(\\pi^-,K^+){}^{10}_\\Lambda\\mbox{Li}$ reaction measured at KEK cannot be explained by production via $\\Sigma^-$ admixture as a doorway state.

  4. CT Scans

    Science.gov (United States)

    ... cross-sectional pictures of your body. Doctors use CT scans to look for Broken bones Cancers Blood clots Signs of heart disease Internal bleeding During a CT scan, you lie still on a table. The table ...

  5. Thyroid scan

    Science.gov (United States)

    ... PET scan Skin nodules Thyroid cancer Thyroid cancer - medullary carcinoma Thyroid cancer - papillary carcinoma Toxic nodular goiter ... Topics Hyperthyroidism Hypothyroidism Nuclear Scans Thyroid Cancer Thyroid Diseases Thyroid Tests Browse the Encyclopedia A.D.A. ...

  6. Effect of alkohols as hardening-accelerating admixtures on the cement properties

    OpenAIRE

    Флейшер, Ганна Юріївна; Токарчук, Володимир Володимирович; Василькевич, Олександр Іванович; Свідерський, Валентин Анатолійович

    2014-01-01

    The effect of alcohols as hardening-accelerating admixtures on physicomechanical properties of cement, particularly strength indexes in early hardening period is investigated. Alcohols can be used as an effective hardening accelerators of cement. The effectiveness of the influence of alcohols on the cement properties depends on their spatial structure and the number of hydroxyl groups. It was found that the largest increase in the cement strength is promoted by individual admixtures of alcoho...

  7. Finding new solutions in pediatric parenteral admixtures: how to improve quality and to deal with shortages

    OpenAIRE

    Dorota Watrobska-Swietlikowska; Anna Kwidzynska; Agnieszka Szlagatys-Sidorkiewicz; Malgorzata Sznitowska; Stanislaw Klek

    2014-01-01

    Introduction: Pediatric parenteral nutrition enables normal growth even of preterm infants. Those children require, however, tailored parenteral nutrition and the creation of such can be challenging due to the risk of instability and shortages. Objective: Prototypical parenteral admixtures were created using different calcium salts (organic and inorganic) and different lipid emulsions and tested for stability. 36 of parenteral admixtures containing two types of calcium salts: chloride or gluc...

  8. Diffusion Decay Coefficient for Chloride Ions of Concrete Containing Mineral Admixtures

    OpenAIRE

    Jae-Im Park; Kwang-Myong Lee; Soon-Oh Kwon; Su-Ho Bae; Sang-Hwa Jung; Sung-Won Yoo

    2016-01-01

    The diffusion coefficient for chloride ions and the diffusion decay coefficient for chloride ions are essential variables for a service life evaluation of concrete structures. They are influenced by water-binder ratio, exposure condition, curing temperature, cement type, and the type and use of mineral admixture. Mineral admixtures such as ground granulated blast furnace slag, fly ash, and silica fume have been increasingly used to improve resistance against chloride ions penetration in concr...

  9. Whole genome scanning and association mapping identified a significant association between growth and a SNP in the IFABP-a gene of the Asian seabass

    OpenAIRE

    Xia, Jun Hong; Lin, Grace; He, Xiaoping; Liu, Peng; Liu, Feng; Sun, Fei; Tu, Rongjian; Yue, Gen Hua

    2013-01-01

    Background Aquaculture is the quickest growing sector in agriculture. However, QTL for important traits have been only identified in a few aquaculture species. We conducted QTL mapping for growth traits in an Asian seabass F2 family with 359 individuals using 123 microsatellites and 22 SNPs, and performed association mapping in four populations with 881 individuals. Results Twelve and nine significant QTL, as well as 14 and 10 suggestive QTL were detected for growth traits at six and nine mon...

  10. 3D Laser Scanning Technology-based Historic Building Mapping for Historic Preservation: A Case Study of Shang Shu Di in Fujian Province, China

    OpenAIRE

    Yuanyi, Zhang; Zhang, Ying; Zhenjiang, Shen; Nishino, Tatsuya; Xiaojuan, Chen

    2015-01-01

    Historic preservation, adaptive reuse, and sustainable urban design that considers the full range of social, environmental, and economic factors is an essential component of sustainable urban development, while the mapping of historic buildings which can be archived and extracted for application, is the basic work on the protection of historic buildings and adaptive reuse. Traditional mapping methods need more time and more workers, and there are measured omissions, mistakes and other issues ...

  11. A Novel Admixture-Based Pharmacogenetic Approach to Refine Warfarin Dosing in Caribbean Hispanics.

    Directory of Open Access Journals (Sweden)

    Jorge Duconge

    Full Text Available This study is aimed at developing a novel admixture-adjusted pharmacogenomic approach to individually refine warfarin dosing in Caribbean Hispanic patients.A multiple linear regression analysis of effective warfarin doses versus relevant genotypes, admixture, clinical and demographic factors was performed in 255 patients and further validated externally in another cohort of 55 individuals.The admixture-adjusted, genotype-guided warfarin dosing refinement algorithm developed in Caribbean Hispanics showed better predictability (R2 = 0.70, MAE = 0.72mg/day than a clinical algorithm that excluded genotypes and admixture (R2 = 0.60, MAE = 0.99mg/day, and outperformed two prior pharmacogenetic algorithms in predicting effective dose in this population. For patients at the highest risk of adverse events, 45.5% of the dose predictions using the developed pharmacogenetic model resulted in ideal dose as compared with only 29% when using the clinical non-genetic algorithm (p<0.001. The admixture-driven pharmacogenetic algorithm predicted 58% of warfarin dose variance when externally validated in 55 individuals from an independent validation cohort (MAE = 0.89 mg/day, 24% mean bias.Results supported our rationale to incorporate individual's genotypes and unique admixture metrics into pharmacogenetic refinement models in order to increase predictability when expanding them to admixed populations like Caribbean Hispanics.ClinicalTrials.gov NCT01318057.

  12. Influences of a New Admixture MX on Concrete Durability

    Institute of Scientific and Technical Information of China (English)

    MA Baoguo; DONG Rongzhen; ZHU Hongbo; ZHANG Li; ZHONG Kaihong; HE Xingyang; LI Zongjin

    2005-01-01

    The performance of concrete with a new admixture MX was studied by using the freeze-thaw cycle, permeability and chemical attack test. The experimental results show that MX improves the durability of concrete. Within the optimum proportion ranges from 0.1%to 1%,the compressive strength of concrete after freeze-thaw is increased by 20%-50%,and Young's modulus can be increased by 3.76-5.64 times.The strength and weight loss of concrete with 0.4%MX are respectively decreased by 28% and 60% after hydrochloric acid attack.The strength and weight loss of concrete with 0.4% MX are decreased by 5%-20% after sulfuric acid and sodium sulfate attack.The permeability of concrete with 1% MX at 28 days can be decreased by more than 30%. The investigation of the negative temperature property of MX and analysis on concrete composition and microstructure by MIP reveal that the heat conduction is resisted and the freezing procedure of solution in concrete pore is retarded due to the adding of MX. Moreover,the pore structure of concrete with MX is improved, thus improving the durability. Based on this study, a resistance model of MX to block the heat and mass transference was proposed, and the mechanism of durability improvement of concrete with MX was explained.

  13. A slide-rule for assessment of venous admixture.

    Science.gov (United States)

    Zetterström, H

    1989-04-01

    Determination of venous admixture (physiological shunt, Qva/Qt) requires analysis of both arterial and mixed venous blood. When a pulmonary arterial catheter is not in use, the pulmonary oxygenating capacity may be assessed from arterial blood gas data, the fraction of inspired oxygen (FIO2) and an assumed value of the arterial-mixed venous oxygen content difference. To facilitate this process, a slide-rule based on the "virtual shunt" concept is presented. It permits rapid assessment of Qva/Qt from known values of arterial oxygen tension (PaO2) or saturation (SaO2) and FIO2 and may promote the choice of appropriate FIO2. The limitations of the slide-rule were studied theoretically and its validity was tested by comparing 100 determinations of virtual shunt with the corresponding Qva/Qt values. The slide-rule was found to estimate Qva/Qt more accurately than commonly used oxygenation indices such as the PaO2/FIO2 ratio. PMID:2499154

  14. Influence of heart rhythm, breathing and arm position during computed tomography scanning on the registration accuracy of electro anatomical map (EAM) images, left atrium three-dimensional computed tomography angiography images, and fluoroscopy time during ablation to treat atrial fibrillation

    International Nuclear Information System (INIS)

    In CARTOMERGE for treatment of atrial fibrillation (AF) by ablation, by integrating electro anatomical map (EAM) and left atrium three-dimensional computed tomography angiography (3D-CTA) images, identification of the ablation points is simplified and the procedure can be made carried out more rapidly. However, the influence that heart rhythm, breathing and arm position during CT scanning have on registration accuracy and fluoroscopy time is not clear. To clarify the influence on registration accuracy and fluoroscopy time of heart rhythm, breathing and arm position during CT scanning. The patients were CT-scanned during both sinus rhythm (SR) and AF in each study subject. We evaluated the registration accuracy of images reconstructed between the cardiac cycle and assessed the registration accuracy and fluoroscopy time of images obtained during inspiratory breath-hold, expiratory breath-hold and up and down position of the arm. Although the registration accuracy of the EAM image and left atrium 3D-CTA image showed a significant difference during SR, no significant difference was seen during AF. Expiratory breath-hold and down position of the arm resulted in the highest registration accuracy and the shortest fluoroscopy time. However, arm position had no significant effect on registration accuracy. Heart rhythm and breathing during CT scanning have a significant effect on the registration accuracy of EAM images, left atrium 3D-CTA images, and fluoroscopy time. (author)

  15. A Genome Scan to Detect Quantitative Trait Loci for Economically Important Traits in Holstein Cattle Using Two Methods and a Dense Single Nucleotide Polymorphism Map

    NARCIS (Netherlands)

    Daetwyler, H.D.; Schenkel, F.S.; Sargolzaei, M.; Robinson, J.A.B.

    2008-01-01

    Genome scans for detection of bovine quantitative trait loci (QTL) were performed via variance component linkage analysis and linkage disequilibrium single-locus regression (LDRM). Four hundred eighty-four Holstein sires, of which 427 were from 10 grandsire families, were genotyped for 9,919 single

  16. Extensive Admixture and Selective Pressure Across the Sahel Belt.

    Science.gov (United States)

    Triska, Petr; Soares, Pedro; Patin, Etienne; Fernandes, Veronica; Cerny, Viktor; Pereira, Luisa

    2015-12-01

    Genome-wide studies of African populations have the potential to reveal powerful insights into the evolution of our species, as these diverse populations have been exposed to intense selective pressures imposed by infectious diseases, diet, and environmental factors. Within Africa, the Sahel Belt extensively overlaps the geographical center of several endemic infections such as malaria, trypanosomiasis, meningitis, and hemorrhagic fevers. We screened 2.5 million single nucleotide polymorphisms in 161 individuals from 13 Sahelian populations, which together with published data cover Western, Central, and Eastern Sahel, and include both nomadic and sedentary groups. We confirmed the role of this Belt as a main corridor for human migrations across the continent. Strong admixture was observed in both Central and Eastern Sahelian populations, with North Africans and Near Eastern/Arabians, respectively, but it was inexistent in Western Sahelian populations. Genome-wide local ancestry inference in admixed Sahelian populations revealed several candidate regions that were significantly enriched for non-autochthonous haplotypes, and many showed to be under positive selection. The DARC gene region in Arabs and Nubians was enriched for African ancestry, whereas the RAB3GAP1/LCT/MCM6 region in Oromo, the TAS2R gene family in Fulani, and the ALMS1/NAT8 in Turkana and Samburu were enriched for non-African ancestry. Signals of positive selection varied in terms of geographic amplitude. Some genomic regions were selected across the Belt, the most striking example being the malaria-related DARC gene. Others were Western-specific (oxytocin, calcium, and heart pathways), Eastern-specific (lipid pathways), or even population-restricted (TAS2R genes in Fulani, which may reflect sexual selection). PMID:26614524

  17. Stability investigation of total parenteral nutrition admixture prepared in a hospital pharmacy

    Directory of Open Access Journals (Sweden)

    Mirković Dušica

    2008-01-01

    Full Text Available Background/Aim. In the cases when nutrition of patients can not be orally nor enterally performed, parenteral nutrition is a method of the therapy that provides more successful and rapid recovery. In that way, hospitalization can be significantly shorter, healing costs reduced and mortality minimized. Total parenteral nutrition (TPN admixtures are the most complex systems which contain amino acids, carbohydrates, lipid emulsion, macroelectrolytes (Na+, K+, Ca2+, Mg2+, Cl-, SO42-, PO43-, oligoelements, hydro- and liposoluble vitamines, heparin, insulin and water. Concerning the mentioned complexity, special attention should be payed to physicochemical and microbiological stability of a mixture, because of interactions among components, that can be very hard to analyze. The aim of this study was to investigate the problem of stability of TPN admixtures prepared in a hospital pharmacy. Methods. Admixture TPN was aseptically prepared in laminar air - flow environment on the basis of the specified order in supplementing components and additives to basic solutions. Solutions were kept in sterile multicompartment ethylene-vinyl-acetate bags. After preparation and slow homogenization, TPN admixtures were submitted to physicochemical and microbiological stability analyses in various period of time. The assessment of physical stability of TPN admixture was done on the basis of visual inspection, determination of pH value and measuring of particle size. The investigation of sterility and pyrogenic test were performed according to Ph. Yug. V regulations. Results. Physico-chemical and microbiological analyses were applied and no significant changes in visual sense, pH value and droplet size stability of the TPN admixture were observed during the period of 60 hours. The lipid droplets were smaller in size than 5 μm, that is the most common pharmacopoeia requirement. Conclusion. The results of our study confirmed that a TPN admixture prepared in a hospital

  18. Stability of total nutrient admixtures in a dual-chamber flexible container.

    Science.gov (United States)

    Tripp, M G; Menon, S K; Mikrut, B A

    1990-11-01

    The stability of total nutrient admixtures (TNAs) prepared from dextrose and amino acid injections commercially packaged in a dual-chamber container and a safflower-soybean oil fat emulsion was studied. The admixtures studied were divided into two groups. Group 1 admixtures represented 14 combinations of Aminosyn II, dextrose, and Liposyn II. Group 2 admixtures represented 10 combinations of Aminosyn II with Electrolytes, dextrose, and Liposyn II. Amino acid concentrations of 7, 8.5, and 10%, dextrose concentrations of 10, 20, 40, and 50%, and 10 and 20% fat emulsion were used. After the amino acid and dextrose injections were mixed in their original container (Nutrimix, Abbott Laboratories), the fat emulsion was added. One of two combinations of electrolytes and trace metals was then added. Multivitamins were added to each TNA just before 24-hour storage at room temperature (25 +/- 4 degrees C). Admixtures were tested initially and at the conclusion of storage periods of 24 hours at room temperature or nine days at 5 degrees C followed by 24 hours at room temperature. Measurements of pH, emulsion particle size, and weight percent of oil particles larger than 5 microns in diameter (HIAC) were made after visual inspection of each admixture. In selected admixtures, concentrations of individual amino acids and dextrose were determined by chromatographic techniques initially and at the conclusion of storage. The TNAs retained a uniform milk-like appearance throughout both storage periods. The pH values, particle size, HIAC measurements, and amino acid and dextrose concentrations remained essentially unchanged.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2126163

  19. ADSORPTION OF CHROMIUM (VI FROM AQUEOUS SOLUTIONS BY DIFFERENT ADMIXTURES – A BATCH EQUILIBRIUM TEST STUDY

    Directory of Open Access Journals (Sweden)

    K. SHIVA PRASHANTH KUMAR

    2014-08-01

    Full Text Available Wide variety of inorganic compounds such as nutrients and trace metals, organic chemicals, radioactive contaminants and pathogens are commonly present as contaminants in the groundwater. Migration of contaminants in soil involves important mechanisms such as molecular diffusion, dispersion under physical processes, adsorption, precipitation and oxidation - reduction under chemical processes and biodegradation under biological process. Cr (VI is a major and dangerous contaminant as per the ground water is concerned. There are numerous research work carried out with concentrated efforts by the researchers towards removal of Cr (VI contaminant from aqueous solutions. There are few studies relevant to Cr (VI removal with respect to utilization of low cost admixtures and also soil type. In the present study, different low cost admixtures like rice husk (RH, shredded tyre (ST and fly ash (FA are used to understand the performance in removal of Cr (VI from aqueous solution and also two different soil types are used along with the admixture. The results are discussed in terms of sorption capacity and performance of individual admixture and combination of admixture with soil in removal of contaminant. The fly ash, rice husk and shredded tyre admixtures are used and the results revealed that the shredded tyre showed higher performance in removal of contaminant concentration. Also, the soil which has more fine particle content (size<0.075 mm IS sieve showed reasonable reduction in concentration of contaminant at the lower levels of contaminant initial concentration. The sorption capacity results of Cr (VI contaminant, treated with various admixtures are further validated with the published work of other investigators. The shredded tyre (ST showed more adsorption capacity, i.e., 3.283 mg/g at pH of 4.8. For other admixtures, adsorption capacity value is varying in the range of 0.07 mg/g to 1.7 mg/g. Only in case of activated alumina and modified saw dust

  20. DOT Official County Highway Map

    Data.gov (United States)

    Minnesota Department of Natural Resources — The County Highway Map theme is a scanned and rectified version of the original MnDOT County Highway Map Series. The cultural features on some of these maps may be...

  1. Study of the mapping mechanism of ferroelectric domains with the scanning force microscope; Untersuchung der Abbildungsmechanismen ferroelektrischer Domaenen mit dem Rasterkraftmikroskop

    Energy Technology Data Exchange (ETDEWEB)

    Jungk, T.

    2006-12-15

    The piezo-force microscopy (PFM) allows the mapping of ferroelectric domains until the nanometer range. In spite of its simple function principle it was hitherto not completely understood. In ordser to develop the PFM further to a quantitative analysis method its methodical aspects were analyzed. It was shown that the fundamental mapping mechanism is based on the inverse piezo-effect. Different artefacts to be found in the literature could therefore be reduced to a measurement background. Furthermore the influence of the electrode geometry was analyzed. The width of doamin walls was systematically measured and simulated with a mode, whereby a maximal resolution of 17 nm was reached. By the development of a correction procedure for the exact detection of the forces acting on the spring-beam the lateral signals measured on domain walls could by newly interpreted. So the ''Lateral Electrostatic Force Microscopy'' was developed.

  2. The Mechanism of the Eeffect of Mineral Admixtures on the Expansion of Aalkali-silica Reaction

    Institute of Scientific and Technical Information of China (English)

    WANG Aiqin; Niu Jishou; ZHANG Chengzhi

    2008-01-01

    On the base of the influence rule of silica fume, slag and fly ash on alkali-silica reaction under the condition of 70℃, the mechanism of the effect of mineral admixtures on alkali-silica reaction is studied further in the paper. The results show that the effects of mineral admixtures on alkali-silica reaction are mainly chemistry effect and surface physichemistry effect. Under suitable condition, the chemistry effect may make alkali-silica reaction to be inhibited effectively, but the physichemistry effect only make alkali-silica reaction to be delayed. The chemistry effect and the physichemistry effect of minerals admixture are relative to the content of Ca(OH)2 in system. Under the condition that there is a large quantity of Ca(OH)2, mineral admixture cannot inhibit alkali-silica reaction effectively. Only when Ca(OH)2 in the system is very less, it is possible that mineral admixture inhibits alkali-silica reaction effectively.

  3. Efficacy of Industrial waste admixture in Improving Engineering Performance of Clayey soil – A quantitative study

    Directory of Open Access Journals (Sweden)

    Kiran B. Biradar

    2014-09-01

    Full Text Available Infrastructure and industrialization serves as a back bone for a country’s economy. However due to rapid industrialization there exist a problem in the form of waste accumulation and subsequent problems due to their disposal & effects of waste. In infrastructure development, roads play a major role. In general pavement construction needs bulk quantities of good soil keeping in view of the service and longevity aspects. Due to limitation in availability of good soil, often the cost of projects escalates. An ideal solution lies for reducing project cost, increasing longevity and reduce accumulation of waste shall be through utilization of industrial waste combined with weak soil for pavement construction. Few types of waste materials namely crusher dust, fly ash and Steel slag waste are popular as admixtures in improving weak soils. This paper discusses the performance of admixtures in improving weak soil through mechanical stabilization. Results of tests on index and engineering properties of mechanically stabilized clayey soil with industrial waste admixtures namely, crusher dust, fly ash and steel slag are presented for different admixture contents and test conditions. A comparison is made based on improved performance. It is observed that Steel slag is proven to be effective over other types. From the results optimum content of admixture for a given improvement is suggested.

  4. Effect of Gum Arabic karroo as a Water-Reducing Admixture in Concrete

    Directory of Open Access Journals (Sweden)

    Rose Mbugua

    2016-01-01

    Full Text Available Concrete is one of the most popular construction materials in the world. Chemical admixtures are ingredients added to concrete to enhance its properties. However, most chemical admixtures on the market today are expensive, thereby making them out of reach for small consumers of concrete. In Africa, use of chemical admixtures is rare despite the harsh weather conditions. In the current study, Gum from Acacia karroo (GAK was used as a water-reducing admixture in concrete. A slump test, density and compressive strength were studied using different dosages of GAK while neat concrete was the control. Results showed that slump increased by 200% at a 2% dosage of GAK. This enabled reduction of water-to-binder (w/b ratio from 0.61 to 0.48 for samples with a 3% dosage. Reduction in w/b resulted in increased compressive strength of 37.03% above the control after 180 days of curing for a 3% dosage. XRD studies also showed a decreased rate of hydration in the presence of GAK in concrete. It was concluded that GAK can be used in concrete as a water-reducing admixture, which is environmentally-friendly, thus producing sustainable and greener concrete.

  5. Mechanical characteristics of hardened concrete with different mineral admixtures: a review.

    Science.gov (United States)

    Ayub, Tehmina; Khan, Sadaqat Ullah; Memon, Fareed Ahmed

    2014-01-01

    The available literature identifies that the addition of mineral admixture as partial replacement of cement improves the microstructure of the concrete (i.e., porosity and pore size distribution) as well as increasing the mechanical characteristics such as drying shrinkage and creep, compressive strength, tensile strength, flexural strength, and modulus of elasticity; however, no single document is available in which review and comparison of the influence of the addition of these mineral admixtures on the mechanical characteristics of the hardened pozzolanic concretes are presented. In this paper, based on the reported results in the literature, mechanical characteristics of hardened concrete partially containing mineral admixtures including fly ash (FA), silica fume (SF), ground granulated blast furnace slag (GGBS), metakaolin (MK), and rice husk ash (RHA) are discussed and it is concluded that the content and particle size of mineral admixture are the parameters which significantly influence the mechanical properties of concrete. All mineral admixtures enhance the mechanical properties of concrete except FA and GGBS which do not show a significant effect on the strength of concrete at 28 days; however, gain in strength at later ages is considerable. Moreover, the comparison of the mechanical characteristics of different pozzolanic concretes suggests that RHA and SF are competitive. PMID:24688443

  6. Genetic admixture and lineage separation in a southern Andean plant

    Science.gov (United States)

    Morello, Santiago; Sede, Silvana M.

    2016-01-01

    varieties of E. alpina: var. alpina is more closely related to E. rubra and other species than to its own counterpart E. alpina var. carmelitana. Geometric morphometrics analysis (Elliptic Fourier descriptors) revealed significant differences in leaf shape between varieties. We found that diversity in Escallonia species analyzed here is geographically structured and deep divergence between varieties of E. alpina could be associated to ancient evolutionary events like orogeny. Admixture in southern populations could be the result of hybridization at the margins of the parental species’ distribution range. PMID:27179539

  7. CT scan

    Science.gov (United States)

    ... come from a CT scan. Some people have allergies to contrast dye. Let your doctor know if you have ... vein contains iodine. If you have an iodine allergy, a type of contrast may cause nausea or vomiting , sneezing , itching , or ...

  8. MRI Scans

    Science.gov (United States)

    Magnetic resonance imaging (MRI) uses a large magnet and radio waves to look at organs and structures inside your body. Health care professionals use MRI scans to diagnose a variety of conditions, from ...

  9. African and non-African admixture components in African Americans and an African Caribbean population.

    Science.gov (United States)

    Murray, Tanda; Beaty, Terri H; Mathias, Rasika A; Rafaels, Nicholas; Grant, Audrey Virginia; Faruque, Mezbah U; Watson, Harold R; Ruczinski, Ingo; Dunston, Georgia M; Barnes, Kathleen C

    2010-09-01

    Admixture is a potential source of confounding in genetic association studies, so it becomes important to detect and estimate admixture in a sample of unrelated individuals. Populations of African descent in the US and the Caribbean share similar historical backgrounds but the distributions of African admixture may differ. We selected 416 ancestry informative markers (AIMs) to estimate and compare admixture proportions using STRUCTURE in 906 unrelated African Americans (AAs) and 294 Barbadians (ACs) from a study of asthma. This analysis showed AAs on average were 72.5% African, 19.6% European and 8% Asian, while ACs were 77.4% African, 15.9% European, and 6.7% Asian which were significantly different. A principal components analysis based on these AIMs yielded one primary eigenvector that explained 54.04% of the variation and captured a gradient from West African to European admixture. This principal component was highly correlated with African vs. European ancestry as estimated by STRUCTURE (r(2)=0.992, r(2)=0.912, respectively). To investigate other African contributions to African American and Barbadian admixture, we performed PCA on approximately 14,000 (14k) genome-wide SNPs in AAs, ACs, Yorubans, Luhya and Maasai African groups, and estimated genetic distances (F(ST)). We found AAs and ACs were closest genetically (F(ST)=0.008), and both were closer to the Yorubans than the other East African populations. In our sample of individuals of African descent, approximately 400 well-defined AIMs were just as good for detecting substructure as approximately 14,000 random SNPs drawn from a genome-wide panel of markers. PMID:20717976

  10. Based on Three-Dimensional Laser Scan Technology of Landslide Topographic Map Creation Research%基于3维激光扫描技术的滑坡体地形图制作研究

    Institute of Scientific and Technical Information of China (English)

    焦学军

    2013-01-01

    采用3维激光扫描技术快速采集滑坡体地形点云信息,并提取滑坡体微地貌信息,为滑坡监测提供基础技术支持。3维激光扫描技术的数据处理主要包括外业数据采集、点云数据配准、地貌数据获取与非地貌点云数据过滤、地形图生成等过程,并着重介绍其工作原理与处理方法。采用3维激光扫描技术能够高效准确实时的监测地质灾害,对预防灾害的发生提供了决策作用。%The point cloud information has been rapid collected by three -dimensional laser scan technology , and the landslide micro-photography information has been extracted from it .This informationprovides the infrastructure technology support for the landslide mo-nitoring.The data processing by three -dimensional laser scan technology mainly includes:field data collection , point cloud data reg-istration, geomorphology information acquisition ,non-geomorphology data filtration , topographic map creation .This paper emphati-cally introduces the working principle and processing method of three-dimensional laser scan technology .The monitoring of geological hazard is high efficient , accurate and real -time though three-dimensional laser scan technology .This method provides decision -making function for disaster prevention .

  11. Y-STR diversity and ethnic admixture in White and Mulatto Brazilian population samples

    OpenAIRE

    Luzitano Brandão Ferreira; Celso Teixeira Mendes-Junior; Cláudia Emília Vieira Wiezel; Marcelo Rizzatti Luizon; Aguinaldo Luiz Simões

    2006-01-01

    We investigated 50 Mulatto and 120 White Brazilians for the Y-chromosome short tandem repeat (Y-STR) markers (DYS19, DYS390, DYS391, DYS392 and DYS393) and found 79 different haplotypes in the White and 35 in the Mulatto sample. Admixture estimates based on allele frequencies showed that the admixture of the white sample was 89% European, 6% African and 5% Amerindian while the Mulatto sample was 93% European and 7% African. Results were consistent with historical records of the directional ma...

  12. Y-STR diversity and ethnic admixture in White and Mulatto Brazilian population samples

    Directory of Open Access Journals (Sweden)

    Luzitano Brandão Ferreira

    2006-01-01

    Full Text Available We investigated 50 Mulatto and 120 White Brazilians for the Y-chromosome short tandem repeat (Y-STR markers (DYS19, DYS390, DYS391, DYS392 and DYS393 and found 79 different haplotypes in the White and 35 in the Mulatto sample. Admixture estimates based on allele frequencies showed that the admixture of the white sample was 89% European, 6% African and 5% Amerindian while the Mulatto sample was 93% European and 7% African. Results were consistent with historical records of the directional mating between European males and Amerindian or African females.

  13. Portland cement hydration in the presence of admixtures: black gram pulse and superplasticizer

    Directory of Open Access Journals (Sweden)

    Viveka Nand Dwivedi

    2008-12-01

    Full Text Available Effect of admixtures such as black gram pulse (BGP and sulfonated naphthalene based superplasticizer (SP on the hydration of Portland cement has been studied. The hydration characteristics of OPC in the presence of BGP and SP were studied with the help of non evaporable water content determinations, calorimetric method, Mössbauer spectroscopic and atomic force microscopic techniques. Results have shown that both BGP and SP get adsorbed at the surface of cement and its hydration products. The hydration of Portland cement is retarded in the presence of both the admixtures and nanosize hydration products are formed.

  14. Tensile strength of green concrete with fly ash and chemical admixtures

    Energy Technology Data Exchange (ETDEWEB)

    Ravina, D. [Technion-Israel Institute of Technology, Haifa (Israel). Faculty of Civil Engineering, National Building Research Institute

    1995-08-01

    The effect of Class F coal fly ash of marginal quality, as partial replacement for fine sand, and of chemical admixtures (water-reducing and retarding and high-rank water reducer) on the tensile strength of green concrete was investigated. The tests show that the fly ash significantly increased (by 25 to 40%) the tensile strength at 2 to 4 hours after mixing, compared with `similar` mixes without fly ash. On the other hand, the chemical admixtures with retarding properties significantly slowed down its growth over the first few hours. 4 refs., 7 figs., 6 tabs.

  15. Effects of drying conditions, admixtures and specimen size on shrinkage strains

    International Nuclear Information System (INIS)

    The paper presents the results of an experimental investigation on the effects of drying conditions, specimen size and presence of plasticizing admixture on the development of shrinkage strains. The measurements are taken in a harsh (50 deg. C and 5% R.H.) and a moderate environment (28 deg. C and 50% R.H.). The results include strain development at various levels of cross sections of concrete prisms. The drying conditions are found to be the dominant parameter affecting the shrinkage strain development particularly in specimens of smaller sizes. The effect of plasticizing admixture on shrinkage strains is negligible

  16. Scanning system

    International Nuclear Information System (INIS)

    An improved transversally cutting radionuclide scanning system is described which can be used for medical diagnosis and medical treatment of men, particularly, for brain investingations. 99mTc43 is named as a radionuclide. The device described is more sensitive, and displays results in a shorter period of time than devices known until now. By means of laser emitting diodes a continuous transmission and collection of signals is obtained, due to a rotating picture framework of offset and meshing detectors surrounding completely the scanning field around a single rotation axis - coaxialy with the axis of the head. Signals are processed and displayed by a connected computer. Description in detail, 7 figures. (UWI)

  17. Chemical Stability of Admixtures Combining Ziconotide with Morphine or Hydromorphone During Simul ated Intrathecal Administration.

    Science.gov (United States)

    Shields, David; Montenegro, Rick; Ragusa, Matthew

    2005-10-01

    Objective.  To determine the stability of admixtures combining ziconotide with morphine or hydromorphone under simulated intrathecal infusions. Materials and Methods.  Admixtures of ziconotide (25 µg/mL) with morphine or hydromorphone (both at 35 mg/mL) were stored in Medtronic SynchroMed® II pumps at 37°C, and in control vials at 37°C and 5°C. Drug concentrations were determined using high-performance liquid chromatography. Results.  The ziconotide pump concentration with morphine declined to 79% of initial in 17 days, and to 88% of initial after 25 days with hydromorphone. Ziconotide concentrations in control vials stored at 37°C displayed similar rates of decay, but vials stored at 5°C exhibited no ziconotide loss. A statistical evaluation of the two combinations shows ziconotide-hydromorphone retaining 80% stability for 40 days (extrapolated), compared to 15 days for ziconotide-morphine. Morphine and hydromorphone were stable in the presence of ziconotide under all conditions. Conclusions.  Ziconotide-hydromorphone admixtures were more stable than ziconotide-morphine admixtures. PMID:22151554

  18. Admixture analysis and stocking impact assessment in brown trout ( Salmo trutta ), estimated with incomplete baseline data

    DEFF Research Database (Denmark)

    Hansen, Michael Møller; Eg Nielsen, Einar; Bekkevold, Dorte; Mensberg, Karen-Lise Dons

    2001-01-01

    . Consequently, stocking had little effect on improving fisheries. In one population, the genetic contribution by domesticated trout was small, whereas in the other population, some genetic impact was suggested. Admixture in this sample of anadromous trout despite absence of stocked domesticated trout could be...

  19. COMPUTER DESIGN OF PROCESSES OF MIGRATION OF ADMIXTURES IN NATURAL WATERS STREAMS

    OpenAIRE

    Savenko, V.; Bondarenko, L.

    2006-01-01

    In work new complex approach of research of processes of transfer of harmful admixtures is offered in natural streams, which is founded on the use of methods of three-dimensional computer design. Basic mathematical equalizations, description of software products, examples of numeral calculations, are resulted on the basis of the offered method

  20. Diffusion Decay Coefficient for Chloride Ions of Concrete Containing Mineral Admixtures

    Directory of Open Access Journals (Sweden)

    Jae-Im Park

    2016-01-01

    Full Text Available The diffusion coefficient for chloride ions and the diffusion decay coefficient for chloride ions are essential variables for a service life evaluation of concrete structures. They are influenced by water-binder ratio, exposure condition, curing temperature, cement type, and the type and use of mineral admixture. Mineral admixtures such as ground granulated blast furnace slag, fly ash, and silica fume have been increasingly used to improve resistance against chloride ions penetration in concrete structures built in an offshore environment. However, there is not enough measured data to identify the statistical properties of diffusion decay coefficient for chloride ions in concrete using mineral admixtures. This paper is aimed at evaluating the diffusion decay coefficient for chloride ions of concrete using ordinary Portland cement or blended cement. NT BUILD 492 method, an electrophoresis experiment, was used to measure the diffusion coefficient for chloride ions with ages. It was revealed from the test results that the diffusion decay coefficient for chloride ions was significantly influenced by W/B and the replacement ratio of mineral admixtures.

  1. Zinc content of commercial diluents widely used in drug admixtures prepared for intravenous infusion.

    Science.gov (United States)

    Desai, Narendra R; Shah, Syed M; Koczone, Julianna; Vencl-Joncic, Maja; Sisto, Christopher; Ludwig, Stephen A

    2007-01-01

    During ongoing quality improvement efforts with two Wyeth parenteral products, Protonix and Zosyn, we noted that dosing solutions prepared from the products yielded inconsistent results on the United States Pharmacopeia Chapter 788 test for subvisible particulates. This manuscript discusses variables that have a direct impact on intravenous products meeting compendial monograph specifications under conditions that are encountered in the clinical setting. The rubber stoppers of vials used for parenteral products, different parts of commercial admixture bags, and the tubing of the administration sets and devices contain residual amounts of metal ions, plasticizers, and other additives incorparated for specific functions. The transition metal ions, including zinc and copper, may leach into drug products during manufacture and during storage of dosing admixture bags prepared for infusion in hospital pharmacies or clinics. The metal ions may compromise the quality of the infusion admixture through catalytic drug degradation and/or generation of undesirable metal ion complexes, which may convert soluble drug molecules into insoluble particulates. To preserve the quality of the drug product, it is essential that metal ion leachables be controlled proactively during manufacture of the drug product; knowledge of metal ion contents in the commercial diluents use for reconstitution, admixture preparation, and flushing of the administration lines is also critical. PMID:23969523

  2. Population admixture, biological invasions and the balance between local adaptation and inbreeding depression

    NARCIS (Netherlands)

    Verhoeven, K.J.F.; Macel, M.; Wolfe, L.M.; Biere, A.

    2011-01-01

    When previously isolated populations meet and mix, the resulting admixed population can benefit from several genetic advantages, including increased genetic variation, the creation of novel genotypes and the masking of deleterious mutations. These admixture benefits are thought to play an important

  3. Phenomenological model of sintering of oxide nuclear fuel with doping admixtures

    Energy Technology Data Exchange (ETDEWEB)

    Baranov, V. G.; Devyatko, Yu. N.; Tenishev, A. V.; Khomyakov, O. V., E-mail: homaykov-o-v@rambler.ru [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) (Russian Federation)

    2015-12-15

    It is shown that a change in the linear dimension of compacted UO{sub 2} in the sintering process is associated with its plastic yielding under the action of the forces of residual stress and capillary forces. From the curves of sintering of a fuel with doping admixtures in various gaseous media, its rate of creep is reduced.

  4. Experimental study on durability improvement of fly ash concrete with durability improving admixture.

    Science.gov (United States)

    Quan, Hong-zhu; Kasami, Hideo

    2014-01-01

    In order to improve the durability of fly ash concrete, a series of experimental studies are carried out, where durability improving admixture is used to reduce drying shrinkage and improve freezing-thawing resistance. The effects of durability improving admixture, air content, water-binder ratio, and fly ash replacement ratio on the performance of fly ash concrete are discussed in this paper. The results show that by using durability improving admixture in nonair-entraining fly ash concrete, the compressive strength of fly ash concrete can be improved by 10%-20%, and the drying shrinkage is reduced by 60%. Carbonation resistance of concrete is roughly proportional to water-cement ratio regardless of water-binder ratio and fly ash replacement ratio. For the specimens cured in air for 2 weeks, the freezing-thawing resistance is improved. In addition, by making use of durability improving admixture, it is easier to control the air content and make fly ash concrete into nonair-entraining one. The quality of fly ash concrete is thereby optimized. PMID:25013870

  5. Experimental Study on Durability Improvement of Fly Ash Concrete with Durability Improving Admixture

    Directory of Open Access Journals (Sweden)

    Hong-zhu Quan

    2014-01-01

    Full Text Available In order to improve the durability of fly ash concrete, a series of experimental studies are carried out, where durability improving admixture is used to reduce drying shrinkage and improve freezing-thawing resistance. The effects of durability improving admixture, air content, water-binder ratio, and fly ash replacement ratio on the performance of fly ash concrete are discussed in this paper. The results show that by using durability improving admixture in nonair-entraining fly ash concrete, the compressive strength of fly ash concrete can be improved by 10%–20%, and the drying shrinkage is reduced by 60%. Carbonation resistance of concrete is roughly proportional to water-cement ratio regardless of water-binder ratio and fly ash replacement ratio. For the specimens cured in air for 2 weeks, the freezing-thawing resistance is improved. In addition, by making use of durability improving admixture, it is easier to control the air content and make fly ash concrete into nonair-entraining one. The quality of fly ash concrete is thereby optimized.

  6. Recycling of tailings from Korea Molybdenum Corporation as admixture for high-fluidity concrete.

    Science.gov (United States)

    Jung, Moon Young; Choi, Yun Wang; Jeong, Jae Gwon

    2011-01-01

    The main objective of this study is to develop an eco-friendly and a large recycling technique of flotation Tailings from korea (TK) from metal mines as construction materials such as admixtures for high-fluidity concrete (HFC). TK used in this study was obtained from the Korea Molybdenum Corporation in operation. TK was used as the alternative material to adjust flowability and viscosity of HFC in the form of powder agent which enables adjustment of concrete compressive strength. In this study, we have performed concrete rheological tests and concrete flowability tests to obtain the quality characteristics of TK for using as the admixture in producing HFC. The results indicated that the adequate mix ratio of cement to TK should be 8:2 (vol%). It is more effective to use the TK as admixture to control flowability, viscosity and strength of HFC than the normal concrete. It was found that TK could be recycled construction materials in bulk such as admixture for HFC, in terms of the economic and eco-friendly aspects. PMID:21113645

  7. What Causes Birth Order-Intelligence Patterns? The Admixture Hypothesis, Revived.

    Science.gov (United States)

    Rodgers, Joseph Lee

    2001-01-01

    Describes why birth order interests both parents and researchers, discussing what really causes apparent birth order effects on intelligence, examining problems with using cross-sectional intelligence data, and noting how to move beyond cross-sectional inferences. Explains the admixture hypothesis, which finds that family size is much more…

  8. Scan Statistics

    CERN Document Server

    Glaz, Joseph

    2009-01-01

    Suitable for graduate students and researchers in applied probability and statistics, as well as for scientists in biology, computer science, pharmaceutical science and medicine, this title brings together a collection of chapters illustrating the depth and diversity of theory, methods and applications in the area of scan statistics.

  9. Genetic analysis of ancestry, admixture and selection in Bolivian and Totonac populations of the New World

    Directory of Open Access Journals (Sweden)

    Watkins W

    2012-05-01

    Full Text Available Abstract Background Populations of the Americas were founded by early migrants from Asia, and some have experienced recent genetic admixture. To better characterize the native and non-native ancestry components in populations from the Americas, we analyzed 815,377 autosomal SNPs, mitochondrial hypervariable segments I and II, and 36 Y-chromosome STRs from 24 Mesoamerican Totonacs and 23 South American Bolivians. Results and Conclusions We analyzed common genomic regions from native Bolivian and Totonac populations to identify 324 highly predictive Native American ancestry informative markers (AIMs. As few as 40–50 of these AIMs perform nearly as well as large panels of random genome-wide SNPs for predicting and estimating Native American ancestry and admixture levels. These AIMs have greater New World vs. Old World specificity than previous AIMs sets. We identify highly-divergent New World SNPs that coincide with high-frequency haplotypes found at similar frequencies in all populations examined, including the HGDP Pima, Maya, Colombian, Karitiana, and Surui American populations. Some of these regions are potential candidates for positive selection. European admixture in the Bolivian sample is approximately 12%, though individual estimates range from 0–48%. We estimate that the admixture occurred ~360–384 years ago. Little evidence of European or African admixture was found in Totonac individuals. Bolivians with pre-Columbian mtDNA and Y-chromosome haplogroups had 5–30% autosomal European ancestry, demonstrating the limitations of Y-chromosome and mtDNA haplogroups and the need for autosomal ancestry informative markers for assessing ancestry in admixed populations.

  10. The Role of Recent Admixture in Forming the Contemporary West Eurasian Genomic Landscape

    Science.gov (United States)

    Busby, George B.J.; Hellenthal, Garrett; Montinaro, Francesco; Tofanelli, Sergio; Bulayeva, Kazima; Rudan, Igor; Zemunik, Tatijana; Hayward, Caroline; Toncheva, Draga; Karachanak-Yankova, Sena; Nesheva, Desislava; Anagnostou, Paolo; Cali, Francesco; Brisighelli, Francesca; Romano, Valentino; Lefranc, Gerard; Buresi, Catherine; Ben Chibani, Jemni; Haj-Khelil, Amel; Denden, Sabri; Ploski, Rafal; Krajewski, Pawel; Hervig, Tor; Moen, Torolf; Herrera, Rene J.; Wilson, James F.; Myers, Simon; Capelli, Cristian

    2015-01-01

    Summary Over the past few years, studies of DNA isolated from human fossils and archaeological remains have generated considerable novel insight into the history of our species. Several landmark papers have described the genomes of ancient humans across West Eurasia, demonstrating the presence of large-scale, dynamic population movements over the last 10,000 years, such that ancestry across present-day populations is likely to be a mixture of several ancient groups [1, 2, 3, 4, 5, 6, 7]. While these efforts are bringing the details of West Eurasian prehistory into increasing focus, studies aimed at understanding the processes behind the generation of the current West Eurasian genetic landscape have been limited by the number of populations sampled or have been either too regional or global in their outlook [8, 9, 10, 11]. Here, using recently described haplotype-based techniques [11], we present the results of a systematic survey of recent admixture history across Western Eurasia and show that admixture is a universal property across almost all groups. Admixture in all regions except North Western Europe involved the influx of genetic material from outside of West Eurasia, which we date to specific time periods. Within Northern, Western, and Central Europe, admixture tended to occur between local groups during the period 300 to 1200 CE. Comparisons of the genetic profiles of West Eurasians before and after admixture show that population movements within the last 1,500 years are likely to have maintained differentiation among groups. Our analysis provides a timeline of the gene flow events that have generated the contemporary genetic landscape of West Eurasia. PMID:26387712

  11. On the integration of Airborne full-waveform laser scanning and optical imagery for Site Detection and Mapping: Monteserico study case

    Science.gov (United States)

    Coluzzi, R.; Guariglia, A.; Lacovara, B.; Lasaponara, R.; Masini, N.

    2009-04-01

    This paper analyses the capability of airborne LiDAR derived data in the recognition of archaeological marks. It also evaluates the benefits to integrate them with aerial photos and very high resolution satellite imagery. The selected test site is Monteserico, a medieval village located on a pastureland hill in the North East of Basilicata (Southern Italy). The site, attested by documentary sources beginning from the 12th century, was discovered by aerial survey in 1996 [1] and investigated in 2005 by using QuickBird imagery [2]. The only architectural evidence is a castle, built on the western top of the hill; whereas on the southern side, earthenware, pottery and crumbling building materials, related to the medieval settlement, could be observed. From a geological point of view, the stratigraphic sequence is composed of Subappennine Clays, Monte Marano sands and Irsina conglomerates. Sporadic herbaceous plants grow over the investigated area. For the purpose of this study, a full-waveform laser scanning with a 240.000 Hz frequency was used. The average point density value of dataset is about 30 points/m2. The final product is a 0.30 m Digital Surface Models (DSMs) accurately modelled. To derive the DSM the point cloud of the ALS was filtered and then classified by applying appropriate algorithms. In this way surface relief and archaeological features were surveyed with great detail. The DSM was compared with other remote sensing data source such as oblique and nadiral aerial photos and QuickBird imagery, acquired in different time. In this way it was possible to evaluate, compare each other and overlay the archaeological features recorded from each data source (aerial, satellite and lidar). Lidar data showed some interesting results. In particular, they allowed for identifying and recording differences in height on the ground produced by surface and shallow archaeological remains (the so-called shadow marks). Most of these features are visible also by the optical

  12. Scanning tunneling microscopy II further applications and related scanning techniques

    CERN Document Server

    Güntherodt, Hans-Joachim

    1995-01-01

    Scanning Tunneling Microscopy II, like its predecessor, presents detailed and comprehensive accounts of the basic principles and broad range of applications of STM and related scanning probe techniques. The applications discussed in this volume come predominantly from the fields of electrochemistry and biology. In contrast to those described in STM I, these studies may be performed in air and in liquids. The extensions of the basic technique to map other interactions are described in chapters on scanning force microscopy, magnetic force microscopy, and scanning near-field optical microscopy, together with a survey of other related techniques. Also described here is the use of a scanning proximal probe for surface modification. Together, the two volumes give a comprehensive account of experimental aspects of STM. They provide essential reading and reference material for all students and researchers involved in this field. In this second edition the text has been updated and new methods are discussed.

  13. Scanning tunneling microscopy II further applications and related scanning techniques

    CERN Document Server

    Güntherodt, Hans-Joachim

    1992-01-01

    Scanning Tunneling Microscopy II, like its predecessor, presents detailed and comprehensive accounts of the basic principles and broad range of applications of STM and related scanning probe techniques. The applications discussed in this volume come predominantly from the fields of electrochemistry and biology. In contrast to those described in Vol. I, these sudies may be performed in air and in liquids. The extensions of the basic technique to map other interactions are described inchapters on scanning force microscopy, magnetic force microscopy, scanning near-field optical microscopy, together with a survey of other related techniques. Also described here is the use of a scanning proximal probe for surface modification. Togehter, the two volumes give a comprehensive account of experimental aspcets of STM. They provide essentialreading and reference material for all students and researchers involvedin this field.

  14. Standard test method for initial screening of corrosion inhibiting admixtures for steel in concrete

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This test method covers a procedure for determining the effects of chemical admixtures on the corrosion of metals in concrete. This test method can be used to evaluate materials intended to inhibit chloride-induced corrosion of steel in concrete. It can also be used to evaluate the corrosivity of admixtures by themselves or in a chloride environment. This test is not applicable for emulsions. 1.2 &solely-SI-units; 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  15. THEORY OF ACTIVE HITTINGS IS IN PROCESSES OF ELECTRO-COAGULATION THE ADMIXTURES IN WATER TECHNOLOGICAL ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    В.В. Березуцький

    2012-10-01

    Full Text Available  In the article theoretical bases of electro-coagulation of admixtures are examined in a water technological environment with the use of theory of the active hittings, which are based on the results of the executed researches and analysis of scientific information. Application of theory of the active hittings is in coagulation, provides high efficiency of process of extraction of admixtures from water environments during minimization of energy consumption and expenses of materials.

  16. Stability investigation of total parenteral nutrition admixture prepared in a hospital pharmacy

    OpenAIRE

    Mirković Dušica; Antunović Mirjana; Putić Vesna; Aleksić Dragana

    2008-01-01

    Background/Aim. In the cases when nutrition of patients can not be orally nor enterally performed, parenteral nutrition is a method of the therapy that provides more successful and rapid recovery. In that way, hospitalization can be significantly shorter, healing costs reduced and mortality minimized. Total parenteral nutrition (TPN) admixtures are the most complex systems which contain amino acids, carbohydrates, lipid emulsion, macroelectrolytes (Na+, K+, Ca2+, Mg2+, Cl-, SO42-, PO43-), oli...

  17. Compatibility between base concrete made with different chemical admixtures and surface hardener

    OpenAIRE

    Pinheiro-Alves, M.ª Teresa; Sequeira, Ana Rita; Bettencourt Ribeiro, António

    2012-01-01

    Many cases of cracking and detachment of the concrete surface have appeared in concrete floors where surface hardeners were used in Portugal. The main causes for cracking and delamination of trowelled concrete pavements are several and it is essential to control bleeding and the time available to perform the finishing operations. Several base concretes were made with different chemical admixtures and one type of surface hardeners. The purpose of this study was evaluating the influence of the ...

  18. Quality assessment of total parenteral nutrition admixtures by the use of fractional factorial design

    Directory of Open Access Journals (Sweden)

    Mirković Dušica

    2013-01-01

    Full Text Available Background/Aim. Parenteral nutrition as a specific aspect of providing nutritients still remains a permanent topic of both theoretical and experimental research. Total parenteral nutrition (TPN admixtures have complex contents making difficult to maintain their stability. The most critical parameter is the diameter of a lipid droplet, i.e. droplet size distribution. It is recommended that droplet size should not be more than 5

  19. PREDICTION OF GLOBAL AND LOCAL SIMMENTAL AND RED HOLSTEIN FRIESIAN ADMIXTURE LEVELS IN SWISS FLECKVIEH CATTLE

    Directory of Open Access Journals (Sweden)

    Negar Khayatzadeh

    2015-09-01

    Full Text Available In this study we estimated levels of local ancestry for individuals of the Swiss Fleckvieh dairy cattle population. It is a composite breed descending from two pure breeds, Simmental (SIM and Red Holstein Friesian (RHF. Illumina BovineSNP50 Beadchip genotyping data for a total of 500 pure and admixed animals were used for the analysis. The global ancestries estimated by Hidden Markov model were 0.68 and 0.32 for RHF and SIM respectively. Local ancestry levels investigated along chromosomes 2, 3 and 13 indicated that there were some regions across the chromosomes exhibiting substantial fluctuations in admixture. On chromosome 2, in the range of 28 to 31, 41 to 46 and 54 to 56 Mb RHF ancestry is substantially higher than average (0.77-0.78. These regions on chromosome 2 are wide, indicating recent admixture. Along the segments on chromosome 2, many QTLs related to dairy, conformation, reproduction, health and carcass traits were found. We observed sharper excess in favour of SIM on chromosome 3, whereas different regions with excess of RHF and SIM were found out on Chromosome 13. At the first part of chromosome 13, an excess of RHF was observed. Moreover, in regions between 40 and 57 Mb excess of SIM, referred to recent admixture was detected. In respect of RHF chromosome segments in admixed animals, dairy, reproduction and health QTLs were found. In positions where more Simmental segments were detected, QTLs related to meat and carcass traits as well as udder health traits were found. In conclusion, the authors believe that estimation of local admixture levels in crossbred populations can add information to the composite breeds history of selection.

  20. Utilization of black liquor as concrete admixture and set retarder aid

    OpenAIRE

    Samar A. El-Mekkawi; Ibrahim M. Ismail; Mohammed M. El-Attar; Alaa A. Fahmy; Samia S. Mohammed

    2011-01-01

    The utilization of black liquor, produced by the pulp and paper industry in Egypt, as a workability aid and set retarder admixture has been investigated. This approach may help eliminate the environmentally polluting black liquor waste. It also provides a low cost by-product, which can be widely used in the construction industry. The properties of black liquor and its performance on concrete at two different ratios of water to cement have been studied. The results revealed that black liquor f...

  1. Semiconductor-metal transition in semiconductor melts with 3d metal admixtures

    International Nuclear Information System (INIS)

    Electrical conductivity and thermoelectric power measurements were performed for liquid semiconductor alloys Se0.5Te0.5 doped with 3d metals in a wide temperature range (up to 1600 K) under ambient pressures of argon gas (up to 30 MPa). Structure changes were studied by means of X-ray diffraction method. The 3d metal admixtures affect electrophysical properties and a temperature of the semiconductor-metal transition (SMT)

  2. Search for admixture of heavy neutrinos with masses between 5 and 55 keV

    OpenAIRE

    Markey, J.; Boehm, F.

    1985-01-01

    Using a magnetic spectrometer at a momentum resolution of 0.3%, we have studied the beta spectrum from 35S. We do not see evidence for the admixture of a heavy neutrino to the usual light (m~0) ν̃e accompanying beta decay, in the mass range between 5 and 50 keV, with a limit for the mixing strength of |U|2

  3. Profile of Intravenous Admixture Compatibility in the Intensive Care Unit (ICU) Patients

    OpenAIRE

    Sharly Dwijayanti; Sylvi Irawati; Eko Setiawan

    2016-01-01

    which may directly impact to the outcome of treatment to the Intensive Care Unit (ICU) patients. The objective of this study was to identify the profile of compatibility and incompatibility among IV admixtures given to the ICU patients. This observational research was conducted prospectively to the patients admitted in the ICU at a private hospital in Surabaya from October–December 2014. In this research, compatibility data of IV drug and its solution was compared with drug brochure and Handb...

  4. Lime-based repair mortars with water-repellent admixtures: laboratory durability assessment

    OpenAIRE

    Nunes, C.; Slížková, Z. (Zuzana)

    2015-01-01

    Conservation of architectural structures using lime binders is currently an important research topic aiming compatibility, durability and sustainability. In this study, lime (L) and lime-metakaolin (LM) mortars were prepared with the addition of water-repellent admixtures: linseed oil, stand oil and a silane based water-repellent. Experimental results demonstrate that oil imparts higher hydrophobicity to both L and LM mixtures. Durability was assessed through freeze-thaw and NaCl crystal...

  5. Intraspecific genetic admixture and the morphological diversification of an estuarine fish population complex.

    Science.gov (United States)

    Dodson, Julian J; Bourret, Audrey; Barrette, Marie France; Turgeon, Julie; Daigle, Gaétan; Legault, Michel; Lecomte, Frédéric

    2015-01-01

    The North-east American Rainbow smelt (Osmerus mordax) is composed of two glacial races first identified through the spatial distribution of two distinct mtDNA lineages. Contemporary breeding populations of smelt in the St. Lawrence estuary comprise contrasting mixtures of both lineages, suggesting that the two races came into secondary contact in this estuary. The overall objective of this study was to assess the role of intraspecific genetic admixture in the morphological diversification of the estuarine rainbow smelt population complex. The morphology of mixed-ancestry populations varied as a function of the relative contribution of the two races to estuarine populations, supporting the hypothesis of genetic admixture. Populations comprising both ancestral mtDNA races did not exhibit intermediate morphologies relative to pure populations but rather exhibited many traits that exceeded the parental trait values, consistent with the hypothesis of transgressive segregation. Evidence for genetic admixture at the level of the nuclear gene pool, however, provided only partial support for this hypothesis. Variation at nuclear AFLP markers revealed clear evidence of the two corresponding mtDNA glacial races. The admixture of the two races at the nuclear level is only pronounced in mixed-ancestry populations dominated by one of the mtDNA lineages, the same populations showing the greatest degree of morphological diversification and population structure. In contrast, mixed-ancestry populations dominated by the alternate mtDNA lineage showed little evidence of introgression of the nuclear genome, little morphological diversification and little contemporary population genetic structure. These results only partially support the hypothesis of transgressive segregation and may be the result of the differential effects of natural selection acting on admixed genomes from different sources. PMID:25856193

  6. Intraspecific Genetic Admixture and the Morphological Diversification of an Estuarine Fish Population Complex

    OpenAIRE

    Dodson, Julian J.; Bourret, Audrey; Barrette, Marie France; Turgeon, Julie; Daigle, Gaétan; Legault, Michel; Lecomte, Frédéric

    2015-01-01

    The North-east American Rainbow smelt (Osmerus mordax) is composed of two glacial races first identified through the spatial distribution of two distinct mtDNA lineages. Contemporary breeding populations of smelt in the St. Lawrence estuary comprise contrasting mixtures of both lineages, suggesting that the two races came into secondary contact in this estuary. The overall objective of this study was to assess the role of intraspecific genetic admixture in the morphological diversification of...

  7. Plant cover and water balance in gravel admixtures at an arid waste-burial site

    International Nuclear Information System (INIS)

    Isolation of radioactive waste buried in unsaturated zones will require long-term control of recharge and erosion. Soil covers control recharge at and sites by storing rainwater close enough to the surface to be removed by evapotranspiration. Surface layers of rock or gravel control erosion at sites with sparse vegetation, but can also alter plant habitat and cause recharge through interred waste. As an alternative, gravel mixed into the uppermost soil law may control erosion ever the king-term better than surface gravel layers. Gravel admixtures may also not influence plant establishment or sod water balance in waste-site covers. The interactive effects of gravel admixture concentration, vegetation, and precipitation on soil water content and plant cover were measured at the US Department of Energy's Hanford Site. Results support use of a combination of vegetation and gravel admixtures for erosion control. Vegetation seasonally depleted root zone water storage to about 6.5 volume % regardless of precipitation amount or the presence of gravel admixture amendments. In contrast, yearly increases in soil water storage as deep as 225 cm in plots without vegetation may be a leading indicator of recharge. The composition and abundance of vegetation changed over time and with precipitation amount, but was not influenced by gravel amendments. Seeded wheatgrasses [Agropyron sibericum Wilde and Agropyron dasystachyum (Hook.) Scribn.] established only when irrigated with twice average precipitation, but persisted after the irrigation ceased. Cheatgrass (Bromus tectorum L.) and Russian thistle (Salsola kali L.) colonized areas receiving both irrigation and ambient precipitation. Stands with wheatgrasses extracted water more rapidly and depleted soil water to lower levels than cheatgrass-dominated stands. Increases in gravel cover and near-surface gravel concentrations after 5 yr were evidence of the formation of a protective gravel veneer. 44 refs., 8 figs., 2 tabs

  8. Dissecting the genetic structure and admixture of four geographical Malay populations

    OpenAIRE

    Lian Deng; Boon-Peng Hoh; Dongsheng Lu; Woei-Yuh Saw; Rick Twee-Hee Ong; Anuradhani Kasturiratne; H Janaka de Silva; Bin Alwi Zilfalil; Norihiro Kato; Wickremasinghe, Ananda R; Yik-Ying Teo; Shuhua Xu

    2015-01-01

    The Malay people are an important ethnic composition in Southeast Asia, but their genetic make-up and population structure remain poorly studied. Here we conducted a genome-wide study of four geographical Malay populations: Peninsular Malaysian Malay (PMM), Singaporean Malay (SGM), Indonesian Malay (IDM) and Sri Lankan Malay (SLM). All the four Malay populations showed substantial admixture with multiple ancestries. We identified four major ancestral components in Malay populations: Austrones...

  9. Effect of water-repellent admixtures on the behaviour of aerial lime-based mortars

    OpenAIRE

    Izaguirre, A.; Lanas, J.; Alvarez, J I

    2009-01-01

    Two different anionic surfactants, sodium oleate and calcium stearate, commercialized as water repellents for cement-based mortars, were added to lime-based mortars in order to check whether they were improved by these admixtures. Different properties of lime-based mortars were evaluated: fresh state behaviour through water retention, air content and setting time, hardened state properties such as density, water absorption through capillarity, water vapour permeability, long-term compressive ...

  10. Reduction in nitrate leaching from a concrete waste form by using waterproofing admixture additions

    International Nuclear Information System (INIS)

    Admixture additions of active lime and tricalcium aluminate reduced leach rate about 20% during a seven-day test of a concrete waste form containing a nitrate bearing, aqueous waste. CaO was 5% more effective and, in SEM examination, appeared to hydrate to CaOH which expanded in the concrete pores and blocked water movement. Over time, this compound appeared to dissolve slowly in the water, and the barrier layer it produced slowly receded into the specimen interior

  11. Age of First Suicide Attempt in Men and Women: An Admixture Analysis

    OpenAIRE

    Hilario Blasco-Fontecilla; Alegria, Analucia A; David Delgado-Gomez; Teresa Legido-Gil; Jeronimo Saiz-Ruiz; Oquendo, Maria A; Enrique Baca-Garcia

    2012-01-01

    Objectives. To define different subgroups of suicide attempters according to age at onset of suicide attempts. Methods. Participants were 229 suicide attempters (147 females; 82 males) admitted to a general hospital in Madrid, Spain. We used admixture analysis to determine the best-fitting model for the age at onset of suicide attempts separated by sex. Results. The best fitted model for the age at onset of suicide attempts was a mixture of two gaussian distributions. Females showed an earlie...

  12. Properties of low drying-shrinkage concrete with shrinkage-reducing admixture

    International Nuclear Information System (INIS)

    Effects on drying shrinkage of concrete were tested by using cement, the limestone coarse aggregate and the shrinkage-reducing admixture. As the results, the drying shrinkage of concrete was realized below 400x10-6. By using this low drying-shrinkage concrete, to prevent cracking on concrete structure during the long service life and to secure the measuring accuracy of concrete structure related the accelerator are expected. (author)

  13. Tracing the origin of the east-west population admixture in the Altai region (Central Asia.

    Directory of Open Access Journals (Sweden)

    Mercedes González-Ruiz

    Full Text Available A recent discovery of Iron Age burials (Pazyryk culture in the Altai Mountains of Mongolia may shed light on the mode and tempo of the generation of the current genetic east-west population admixture in Central Asia. Studies on ancient mitochondrial DNA of this region suggest that the Altai Mountains played the role of a geographical barrier between West and East Eurasian lineages until the beginning of the Iron Age. After the 7th century BC, coinciding with Scythian expansion across the Eurasian steppes, a gradual influx of East Eurasian sequences in Western steppes is detected. However, the underlying events behind the genetic admixture in Altai during the Iron Age are still unresolved: 1 whether it was a result of migratory events (eastward firstly, westward secondly, or 2 whether it was a result of a local demographic expansion in a 'contact zone' between European and East Asian people. In the present work, we analyzed the mitochondrial DNA lineages in human remains from Bronze and Iron Age burials of Mongolian Altai. Here we present support to the hypothesis that the gene pool of Iron Age inhabitants of Mongolian Altai was similar to that of western Iron Age Altaians (Russia and Kazakhstan. Thus, this people not only shared the same culture (Pazyryk, but also shared the same genetic east-west population admixture. In turn, Pazyryks appear to have a similar gene pool that current Altaians. Our results further show that Iron Age Altaians displayed mitochondrial lineages already present around Altai region before the Iron Age. This would provide support for a demographic expansion of local people of Altai instead of westward or eastward migratory events, as the demographic event behind the high population genetic admixture and diversity in Central Asia.

  14. Thyroid Scan and Uptake

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Thyroid Scan and Uptake Thyroid scan and uptake uses ... the Thyroid Scan and Uptake? What is a Thyroid Scan and Uptake? A thyroid scan is a ...

  15. Pelvic CT scan

    Science.gov (United States)

    ... axial tomography scan - pelvis; Computed tomography scan - pelvis; CT scan - pelvis ... Risks of CT scans include: Being exposed to radiation Allergic reaction to contrast dye CT scans do expose you to more radiation ...

  16. Cervical spine CT scan

    Science.gov (United States)

    ... cervical spine; Computed tomography scan of cervical spine; CT scan of cervical spine; Neck CT scan ... Risks of CT scans include: Being exposed to radiation Allergic reaction to contrast dye CT scans expose you to more radiation than ...

  17. Sinus CT scan

    Science.gov (United States)

    ... axial tomography scan - sinus; Computed tomography scan - sinus; CT scan - sinus ... Risks of a CT scan includes: Being exposed to radiation Allergic reaction to contrast dye CT scans expose you to more radiation than regular ...

  18. Chemical stability of an admixture combining ziconotide and bupivacaine during simulated intrathecal administration.

    Science.gov (United States)

    Shields, David; Montenegro, Rick; Aclan, Jennifer

    2007-10-01

    Objective.  To determine the stability of an admixture combining ziconotide with bupivacaine hydrochloride during simulated intrathecal infusion under laboratory conditions at 37°. Materials and Methods.  An admixture containing ziconotide (25 µg/mL) and bupivacaine hydrochloride (5 mg/mL) was stored in SynchroMed® II pumps at 37° and in control vials at either 37° or 5°. Using high-performance liquid chromatography, drug concentrations were determined from samples obtained at varying intervals during the 30-day study. Results.  After 30 days, pump ziconotide and bupivacaine hydrochloride concentrations measured an average of 86.9% and 99.4% of their initial concentrations, respectively. Control vials displayed similar degradation rates for both drugs. Statistical evaluation of the ziconotide 95% confidence interval indicated that the ziconotide concentration would meet or exceed 90% and 80% of initial concentration for 22 days and 45 days, respectively. Conclusions.  An admixture containing 25 µg/mL ziconotide and 5 mg/mL bupivacaine hydrochloride was 90% stable for 22 days and 80% stable for 45 days (extrapolated) in SynchroMed® II infusion pumps. PMID:22150945

  19. Effect of Chemical Admixtures on the Engineering Properties of Tropical Peat Soils

    Directory of Open Access Journals (Sweden)

    Bujang B.K. Huat

    2005-01-01

    Full Text Available This research describes a study on the effect of chemical (cement and lime admixtures on the index and engineering properties (compaction and unconfined strength of tropical peat soils. The ordinary Portland cement and hydrated lime were used. The amounts cement and lime added to the peat soil sample, as a percentage of the dry soil mass was in the range of 5-15% and 5-25%, respectively. The results of the study show that the addition of the chemical admixture, cement and lime, can improve the engineering properties of tropical peat soils. The soil liquid limit is found to decrease with an increase in the cement and lime content. The soil maximum dry density is found to increase while the optimum water content is found to decrease with an increase in the cement and lime content. The unconfined compressive strength of the soil is found to increase significantly with increase in cement and lime content, especially after a long curing period. However it is also found that higher organic content of the soil negate the positive effect of the cement and lime in altering (improving the mechanical properties of the soil. When comparing the performance of the cement and lime as a chemical admixture for the tropical peat soil, the ordinary Portland cement appears to perform better than the hydrated lime.

  20. Effects of lithium nitrate admixture on early-age cement hydration

    International Nuclear Information System (INIS)

    Although the benefits of lithium admixtures for mitigation of alkali-silica reaction (ASR) have been well documented, the potential ancillary effects of lithium compounds on cement and concrete remain largely uncharacterized. To examine the effects of the most common lithium admixture - lithium nitrate - on early-age behavior, the admixture was introduced at dosages of 0% to 400% of the recommended dosage to six cements of varying composition and to a cement-fly ash blend. Behavior was examined by isothermal calorimetry and measurements of chemical shrinkage, autogenous shrinkage, and setting time. Results indicate that lithium nitrate accelerates the early hydration of most cements but may retard hydration after 24 h. In the lowest alkali cement tested, set times were shortened in the presence of lithium nitrate by 15-22%. Higher dosages appeared to increase autogenous shrinkage after 40 days. The replacement of cement by Class F fly ash at 20% by weight appeared to diminish the early acceleration effects, but later hydration retardation and autogenous shrinkage were still observed

  1. Study on Strength and Microstructure of Cement-Based Materials Containing Combination Mineral Admixtures

    Directory of Open Access Journals (Sweden)

    Meijuan Rao

    2016-01-01

    Full Text Available The compressive strength of complex binders containing two or three blended mineral admixtures in terms of glass powder (GP, limestone powder (LP, and steel slag powder (SP was determined by a battery solution type compressive testing machine. The morphology and microstructure characteristics of complex binder hydration products were also studied by microscopic analysis methods, such as XRD, TG-DTA, and SEM. The mechanical properties of the cement-based materials were analyzed to reveal the most appropriate mineral admixture type and content. The early sample strength development with GP was very slow, but it rapidly grew at later stages. The micro aggregate effect and pozzolanic reaction mutually occurred in the mineral admixture. In the early stage, the micro aggregate effect reduced paste porosity and the small particles connected with the cement hydration products to enhance its strength. In the later stage, the pozzolanic reaction of some components in the complex powder occurred and consumed part of the calcium hydroxide to form C-S-H gel, thus improving the hydration environment. Also, the produced C-S-H gel made the structure more compact, which improved the structure’s strength.

  2. Chemical stability of ziconotide-clonidine hydrochloride admixtures with and without morphine sulfate during simulated intrathecal administration.

    Science.gov (United States)

    Shields, David; Montenegro, Rick

    2007-10-01

    Objective.  To determine the stability of ziconotide-clonidine hydrochloride admixtures with and without morphine sulfate during simulated intrathecal infusion under laboratory conditions at 37°. Materials and Methods.  Admixtures of ziconotide (25 µg/mL) and clonidine hydrochloride (2 mg/mL) with and without morphine sulfate (35 mg/mL) were stored in Medtronic SynchroMed® II pumps at 37°. Pumps were sampled immediately after filling and at four additional time points over the course of 28 (ziconotide-clonidine hydrochloride admixture) or 20 (ziconotide-clonidine hydrochloride-morphine sulfate admixture) days. Drug concentrations were determined using high-performance liquid chromatography. Results.  Ziconotide concentration exceeded 97% of initial at all time points when combined with clonidine alone; statistical evaluation indicated that both ziconotide and clonidine concentrations would remain above 90% of initial for more than 60 days. When compounded with both clonidine and morphine, ziconotide and clonidine concentrations declined; statistical evaluation indicated that the ziconotide concentration was 70% of initial after 20 days, and that clonidine would remain 90% stable for 42 days. Morphine was stable in the presence of ziconotide and clonidine. Conclusions.  A ziconotide-clonidine admixture was 90% stable for 60 days (extrapolated), and a ziconotide-clonidine-morphine admixture was 70% stable for 20 days. PMID:22150946

  3. Chemical, Mechanical, and Durability Properties of Concrete with Local Mineral Admixtures under Sulfate Environment in Northwest China

    Directory of Open Access Journals (Sweden)

    Qingke Nie

    2014-05-01

    Full Text Available Over the vast Northwest China, arid desert contains high concentrations of sulfate, chloride, and other chemicals in the ground water, which poses serious challenges to infrastructure construction that routinely utilizes portland cement concrete. Rapid industrialization in the region has been generating huge amounts of mineral admixtures, such as fly ash and slags from energy and metallurgical industries. These industrial by-products would turn into waste materials if not utilized in time. The present study evaluated the suitability of utilizing local mineral admixtures in significant quantities for producing quality concrete mixtures that can withstand the harsh chemical environment without compromising the essential mechanical properties. Comprehensive chemical, mechanical, and durability tests were conducted in the laboratory to characterize the properties of the local cementitious mineral admixtures, cement mortar and portland cement concrete mixtures containing these admixtures. The results from this study indicated that the sulfate resistance of concrete was effectively improved by adding local class F fly ash and slag, or by applying sulfate resistance cement to the mixtures. It is noteworthy that concrete containing local mineral admixtures exhibited much lower permeability (in terms of chloride ion penetration than ordinary portland cement concrete while retaining the same mechanical properties; whereas concrete mixtures made with sulfate resistance cement had significantly reduced strength and much increased chloride penetration comparing to the other mixtures. Hence, the use of local mineral admixtures in Northwest China in concrete mixtures would be beneficial to the performance of concrete, as well as to the protection of environment.

  4. IRS SCAN-MAPPING OF THE WASP-WAIST NEBULA (IRAS 16253-2429). I. DERIVATION OF SHOCK CONDITIONS FROM H2 EMISSION AND DISCOVERY OF 11.3 μm PAH ABSORPTION

    International Nuclear Information System (INIS)

    The outflow driven by the Class 0 protostar, IRAS 16253-2429, is associated with bipolar cavities visible in scattered mid-infrared light, which we refer to as the Wasp-Waist Nebula. InfraRed Spectometer (IRS) scan mapping with the Spitzer Space Telescope of a ∼1' x 2' area centered on the protostar was carried out. The outflow is imaged in six pure rotational (0-0 S(2) through 0-0 S(7)) H2 lines, revealing a distinct, S-shaped morphology in all maps. A source map in the 11.3 μm polycyclic aromatic hydrocarbon (PAH) feature is presented in which the protostellar envelope appears in absorption. This is the first detection of absorption in the 11.3 μm PAH feature. Spatially resolved excitation analysis of positions in the blue- and redshifted outflow lobes, with extinction-corrections determined from archival Spitzer 8 μm imaging, shows remarkably constant temperatures of ∼1000 K in the shocked gas. The radiated luminosity in the observed H2 transitions is found to be 1.94 ± 0.05 x 10-5 Lsun in the redshifted lobe and 1.86 ± 0.04 x 10-5 Lsun in the blueshifted lobe. These values are comparable to the mechanical luminosity of the flow. By contrast, the mass of hot (T ∼ 1000 K) H2 gas is 7.95 ± 0.19 x 10-7 Msun in the redshifted lobe and 5.78 ± 0.17 x 10-7 Msun in the blueshifted lobe. This is just a tiny fraction, of order 10-3, of the gas in the cold (30 K), swept-up gas mass derived from millimeter CO observations. The H2 ortho/para ratio of 3:1 found at all mapped points in this flow suggests previous passages of shocks through the gas. Comparison of the H2 data with detailed shock models of Wilgenbus et al. shows the emitting gas is passing through Jump (J-type) shocks. Pre-shock densities of 104 cm-3≤ n H≤ 105 cm-3 are inferred for the redshifted lobe and n H≤ 103 cm-3 for the blueshifted lobe. Shock velocities are 5 km s-1 ≤ vs ≤ 10 km s-1 for the redshifted gas and vs = 10 km s-1 for the blueshifted gas. Initial transverse (to the shock

  5. Public Waters Inventory Maps

    Data.gov (United States)

    Minnesota Department of Natural Resources — This theme is a scanned and rectified version of the Minnesota DNR - Division of Waters "Public Waters Inventory" (PWI) maps. DNR Waters utilizes a small scale...

  6. Influence of Air Temperature on the Performance of Different Water-Reducing Admixtures with Respect to the Properties of Fresh and Hardened Mortar

    OpenAIRE

    Wilson Ricardo Leal Silva; Luiz Roberto Prudêncio; Alexandre Lima Oliveira; Gabriela Damo; Eduardo Tochetto

    2010-01-01

    The performance of water-reducing admixtures used in concrete is affected by the weather conditions to which the concrete mixture is exposed. The most used WRAs are lignosulfonate, naphthalene, and polycarboxylate. However, they react differently to weather conditions, especially to air temperature. Therefore, it can be useful to evaluate how temperature affects admixture performance. In this study, the performance of three admixtures (naphthalene, lignosulfonate, and polycarboxylate) was eva...

  7. Abdominal CT scan

    Science.gov (United States)

    Computed tomography scan - abdomen; CT scan - abdomen; CAT scan - abdomen; CT abdomen and pelvis ... An abdominal CT scan makes detailed pictures of the structures inside your belly (abdomen) very quickly. This test may be used to ...

  8. Shoulder CT scan

    Science.gov (United States)

    CAT scan - shoulder; Computed axial tomography scan - shoulder; Computed tomography scan - shoulder; CT scan - shoulder ... stopping.) A computer creates separate images of the shoulder area. These are called slices. These images can ...

  9. Effectiveness of shrinkage-reducing admixtures on Portland pozzolan cement concrete

    Directory of Open Access Journals (Sweden)

    Videla, C.

    2005-06-01

    Full Text Available Drying shrinkage causes tensile stress in restrained concrete members. Since all structural elements are subject to some degree of restraint, drying shrinkage is regarded to be one of the main causes of concrete cracking. The purpose of the present study was to evaluate the effectiveness of SRA in reducing drying shrinkage strain in Portland pozzolan cement concrete. The major variables examined included slump, admixture type and dose, and specimen size. The measured results indicate that any of the admixtures used in the study significantly reduced shrinkage. Concrete manufactured with shrinkage reducing admixtures shrank an average of 43% less than concrete without admixtures. As a rule, the higher the dose of admixture, the higher was its shrinkage reduction performance. The experimental results were compared to the shrinkage strain estimated with the ACI 209, CEB MC 90, B3, GL 2000, Sakata 1993 and Sakata 2001 models. Although none of these models was observed to accurately describe the behaviour of Portland pozzolan cement concrete with shrinkage reducing admixtures, the Sakata 2001 model, with a weighted coefficient of variation of under 30%, may be regarded to be roughly adequate.

    La retracción por secado es un fenómeno intrínseco del hormigón que produce tensiones de tracción en elementos restringidos de hormigón. Puesto que todos los elementos presentan algún grado de retracción, se considera a la retracción por secado como una de las principales causas de agrietamiento en proyectos de construcción en hormigón. Por lo tanto, el objetivo de esta investigación fue evaluar la efectividad de los aditivos reductores de retracción (SRA en hormigones fabricados con cemento Portland puzolánico. Las variables principales estudiadas incluyen el asentamiento de cono de Abrams, marca y dosis de aditivo reductor de retracción, y tamaño de espécimen de hormigón. Los resultados obtenidos permiten concluir que el uso de

  10. Application of a polycarboxylate ether admixture in RCC dam construction[ACI SP-239

    Energy Technology Data Exchange (ETDEWEB)

    Asmus, S.M.F.; Christensen, B.J.; Varley, N.J. [BASF Construction Chemicals Asia Pacific, Shanghai (China)

    2006-07-01

    Chemical admixtures are used in dam construction to improve plasticity of the dry materials mixture over time. Roller compacted concrete (RCC) has been used on many dam projects in China. However, the use of RCC has frequently resulted in water reduction problems. This paper provided details of an admixture based on polycarboxylate ether (PCE) which was developed to improve the quality of RCC constructions at the JinHong dam in China. Use of the polymer at the JinHong dam resulted in a vibration sensitive concrete that was sustained over time. Under identical mix-design and compaction conditions in the laboratory, specific gravity of the RCC was increased from 2417 kg/m{sup 3} to 2463 kg/m{sup 3}. The high specific gravity of the material resulted in satisfactory strength data from the dam project. The key-ratio of the splitting tensile strength versus compressive strength was higher than 8 per cent in all cases. A key advantage of the tailored PCE-RCC was the short Vebe times sustained over elapsed time in the RCC. Without additional compaction or vibration efforts, the specific density of RCC was better than conventional admixture technologies. The reduced viscosity provided cement paste films which formed on the surface of each layer of the RCC, which resulted in better bonding between the layers. It was concluded that the new PCE polymer is compatible with alternative retarder systems, which contributes to more extensive setting times under strict hydration regimes. 7 refs., 4 tabs., 4 figs.

  11. Effect of poly car boxy late admixtures on portland cement paste setting and rheological behaviour

    Directory of Open Access Journals (Sweden)

    Puertas, F.

    2005-03-01

    Full Text Available The objective of the work was to determine the effects of polycarboxilated-type admixture on the setting times and the rheological properties of different types of cements including CEM I 42.5 R, CEM Il/B-V 42.5 N and CEM III/B 32.5 N, defined according to the UNE EN 197-1:2000 standard. The results show that there is a lineal relationship between the initial setting times and the admixture dosage. Mathematical equations that model this behaviour for each of the cements have been determined. The data obtained from the minislump test and from the rheological parameters determined using the rheometer (plastic viscosity and yield stress point to similar conclusions. It was also verified that the workability effect of the polycarboxilate admixture is most intense for blended cements.

    El objetivo de este trabajo ha sido estudiar el efecto de la dosificación de un aditivo basado en policarboxilatos sobre el inicio de tiempo de fraguado y las propiedades reo lógicas en pastas de diferentes tipos de cemento (CEM 142.5 R, CEM 11/ B-V42.5 NYCEMIII/B 32.5 N-Norma EN 197-1:2000. existe una relación lineal entre el inicio del fraguado y la dosificación del aditivo, se han determinado las ecuaciones matemáticas que describen este comportamiento para cada cemento, los resultados obtenidos sobre la fluidez de la pasta en el ensayo del "minislump" coinciden con la evolución de los valores de los parámetros reológicos (esfuerzo de cizalladura y viscosidad plástica determinados a través de un reómetro. el efecto fluidificante del aditivo superplastificante basado en policarboxilatos es mucho más marcado en cementos que contienen adiciones.

  12. Polar and brown bear genomes reveal ancient admixture and demographic footprints of past climate change

    Science.gov (United States)

    Miller, Webb; Schuster, Stephan C.; Welch, Andreanna J.; Ratan, Aakrosh; Bedoya-Reina, Oscar C.; Zhao, Fangqing; Kim, Hie Lim; Burhans, Richard C.; Drautz, Daniela I.; Wittekindt, Nicola E.; Tomsho, Lynn P.; Ibarra-Laclette, Enrique; Herrera-Estrella, Luis; Peacock, Elizabeth; Farley, Sean; Sage, George K.; Rode, Karyn; Obbard, Martyn E.; Montiel, Rafael; Bachmann, Lutz; Ingólfsson, Ólafur; Aars, Jon; Mailund, Thomas; Wiig, Øystein; Talbot, Sandra L.; Lindqvist, Charlotte

    2012-01-01

    Polar bears (PBs) are superbly adapted to the extreme Arctic environment and have become emblematic of the threat to biodiversity from global climate change. Their divergence from the lower-latitude brown bear provides a textbook example of rapid evolution of distinct phenotypes. However, limited mitochondrial and nuclear DNA evidence conflicts in the timing of PB origin as well as placement of the species within versus sister to the brown bear lineage. We gathered extensive genomic sequence data from contemporary polar, brown, and American black bear samples, in addition to a 130,000- to 110,000-y old PB, to examine this problem from a genome-wide perspective. Nuclear DNA markers reflect a species tree consistent with expectation, showing polar and brown bears to be sister species. However, for the enigmatic brown bears native to Alaska's Alexander Archipelago, we estimate that not only their mitochondrial genome, but also 5–10% of their nuclear genome, is most closely related to PBs, indicating ancient admixture between the two species. Explicit admixture analyses are consistent with ancient splits among PBs, brown bears and black bears that were later followed by occasional admixture. We also provide paleodemographic estimates that suggest bear evolution has tracked key climate events, and that PB in particular experienced a prolonged and dramatic decline in its effective population size during the last ca. 500,000 years. We demonstrate that brown bears and PBs have had sufficiently independent evolutionary histories over the last 4–5 million years to leave imprints in the PB nuclear genome that likely are associated with ecological adaptation to the Arctic environment.

  13. Rectification cleaning AsCl3 from the admixture of oxygen

    Directory of Open Access Journals (Sweden)

    Maznitska O. V.

    2008-06-01

    Full Text Available The process of the rectification cleaning of three-chlorous arsenic from the admixtures of products of his hydrolysis in the atmosphere of chlorous hydrogen has been considered in the article. Dependence of coefficient of relative volatility a three-chlorous arsenic from his concentration in muriatic solution is explored. The conduct of coefficient of relative volatility with concentrations of HCl and AsCl3 is compared. Saving of equalization of balance and equalization of working curve of column at such conduct of process of rectification is shown.

  14. An experimental study of the combustion characteristics of groundnut shell and waste paper admixture briquettes

    OpenAIRE

    O.A Oyelaran; B.O. Bolaji; M.A. Waheed; Adekunle, M.F.

    2015-01-01

    The study was undertaken to assess the heat released of briquettes produced from waste paper and groundnut shell admixture in five mixing ratios (90:10; 80:20; 70:30; 60:40; and 50:50). The briquettes were prepared on an existing motorized briquetting machine. The suitability of briquetted fuel as domestic fuel was studied in terms of flame propagation, afterglow, calorific value, and utilized heat, after sun drying the prepared briquettes for nineteen (19) days. The results of propagation ra...

  15. Compost admixture impact study on water infiltration depth, water front advance and recession in irrigated environment

    International Nuclear Information System (INIS)

    Water is an important life supporting resource and is essential for sustainable food production. Its continued decrease has diverted the attention of researchers to find new ways of efficient irrigation management. Decomposed bio-solids (for example leaves, crop residue, animal waste, municipal solid waste) form the compost and provide friendly environment for enhancing crop production. The present study investigates the effects of compost admixture on water infiltration depth, water advance and recession phase of irrigation event in the field having loamy sand texture. Compost from two sources was used. There were nine experimental plots with 3.5 m width and 45 m length. Compost at the rate of 5 % was incorporated up to a depth of 3 cm in six plots (3 plots of each compost source) and in the remaining three plots no compost was applied. The field was irrigated twice. The results revealed that by using 5% compost admixture by weight the advance time reduced by 23.96% and 26.83 % for first and second irrigation, respectively compared to non compost admixture plots. Results revealed that by using 5 % compost up to 3 cm mixing depth the water infiltration depth decreased 42.97 % at head side of the field and 10.37 % at tail side of field during first irrigation, during second irrigation the water infiltration depth decreased 48.67 % at upper end of the field and 11.28 % at lower end of the field. The significant decrease in water infiltration depth at head side gives uniformity in water infiltration depth along the length of field. The faster movement of the water front with the application of compost admixture reduces the difference in intake opportunity times between the head and far end of the field, thus it improves the performance of the irrigation system. Reduction in the applied water volume to the tone of 23.96% during first irrigation and 26.83% during second irrigation, further supports this improvement in irrigation performance, considering on the advance

  16. An investigation of admixture in an Australian Aboriginal Y-chromosome STR database.

    Science.gov (United States)

    Taylor, Duncan; Nagle, Nano; Ballantyne, Kaye N; van Oorschot, Roland A H; Wilcox, Stephen; Henry, Julianne; Turakulov, Rust; Mitchell, R John

    2012-09-01

    Y-chromosome specific STR profiling is increasingly used in forensic casework. However, the strong geographic clustering of Y haplogroups can lead to large differences in Y-STR haplotype frequencies between different ethnicities, which may have an impact on database composition in admixed populations. Aboriginal people have inhabited Australia for over 40,000 years and until ∼300 years ago they lived in almost complete isolation. Since the late 18th century Australia has experienced massive immigration, mainly from Europe, although in recent times from more widespread origins. This colonisation resulted in highly asymmetrical admixture between the immigrants and the indigenes. A State jurisdiction within Australia has created an Aboriginal Y-STR database in which assignment of ethnicity was by self-declaration. This criterion means that some males who identify culturally as members of a particular ethnic group may have a Y haplogroup characteristic of another ethnic group, as a result of admixture in their paternal line. As this may be frequent in Australia, an examination of the extent of genetic admixture within the database was performed. A Y haplogroup predictor program was first used to identify Y haplotypes that could be assigned to a European haplogroup. Of the 757 males (589 unique haplotypes), 445 (58.8%) were identified as European (354 haplotypes). The 312 non-assigned males (235 haplotypes) were then typed, in a hierarchical fashion, with a Y-SNP panel that detected the major Y haplogroups, C-S, as well as the Aboriginal subgroup of C, C4. Among these 96 males were found to have non-Aboriginal haplogroups. In total, ∼70% of Y chromosomes in the Aboriginal database could be classed as non-indigenous, with only 169 (129 unique haplotypes) or 22% of the total being associated with haplogroups denoting Aboriginal ancestry, C4 and K* or more correctly K(xL,M,N,O,P,Q,R,S). The relative frequencies of these indigenous haplogroups in South Australia (S

  17. No clear effect of admixture betweent two european invading outbreaks of Diabrotica virgifera virgifera in natura

    OpenAIRE

    Cavigliasso, Fanny; Mallez, Sophie,; Spencer, Joseph; Guillemaud, Thomas

    2014-01-01

    In this study, we challenged the hypothesis that admixture may have had a positive impact in the context of the European invasion of the western corn rootworm (WCR), Diabrotica virgifera virgifera, LeConte. This beetle was introduced in Europe from the USA several times since the 1980’s. The multiple introductions of this major pest of cultivated corn led to the formation of two major outbreaks in North Western (NW) Italy and in Central and South Eastern (CSE) Europe that eventually merged in...

  18. A Comparative Study on Compressive and Flexural Strength of Concrete Containing Different Admixtures as Partial Replacement of Cement

    Directory of Open Access Journals (Sweden)

    Apoorv Singh

    2014-09-01

    Full Text Available Concrete is the most widely used material in the world today. This paper is about the comparative study of the flexural strength and compressive strength of concrete when different admixtures are used as partial replacement of cement in the concrete mix. The mineral admixtures that are used here are Silica Fume, Rice Husk Ash and Iron slag as partial replacement of cement. All these materials are industrial waste products and are abundantly available nowadays. These materials have high silica content and pozzolanic properties and can be effectively used as a replacement of cement during the formation of High Performance Concrete. Compressive and Flexural strength are the two most important characteristic of concrete and are calculated for the hardened concrete to analyze the load bearing capacity for design purposes. Thus for the effective judgment of type of mineral admixtures to be used a comparative study is very useful.

  19. Alkali-activated complex binders from class C fly ash and Ca-containing admixtures.

    Science.gov (United States)

    Guo, Xiaolu; Shi, Huisheng; Chen, Liming; Dick, Warren A

    2010-01-15

    Processes that maximize utilization of industrial solid wastes are greatly needed. Sodium hydroxide and sodium silicate solution were used to create alkali-activated complex binders (AACBs) from class C fly ash (CFA) and other Ca-containing admixtures including Portland cement (PC), flue gas desulfurization gypsum (FGDG), and water treatment residual (WTR). Specimens made only from CFA (CFA100), or the same fly ash mixed with 40 wt% PC (CFA60-PC40), with 10 wt% FGDG (CFA90-FGDG10), or with 10 wt% WTR (CFA90-WTR10) had better mechanical performance compared to binders using other mix ratios. The maximum compressive strength of specimens reached 80.0 MPa. Geopolymeric gel, sodium polysilicate zeolite, and hydrated products coexist when AACB reactions occur. Ca from CFA, PC, and WTR precipitated as Ca(OH)(2), bonded in geopolymers to obtain charge balance, or reacted with dissolved silicate and aluminate species to form calcium silicate hydrate (C-S-H) gel. However, Ca from FGDG probably reacted with dissolved silicate and aluminate species to form ettringite. Utilization of CFA and Ca-containing admixtures in AACB is feasible. These binders may be widely utilized in various applications such as in building materials and for solidification/stabilization of other wastes, thus making the wastes more environmentally benign. PMID:19767143

  20. Genetic admixture history of Eastern Indonesia as revealed by Y-chromosome and mitochondrial DNA analysis.

    Science.gov (United States)

    Mona, Stefano; Grunz, Katharina E; Brauer, Silke; Pakendorf, Brigitte; Castrì, Loredana; Sudoyo, Herawati; Marzuki, Sangkot; Barnes, Robert H; Schmidtke, Jörg; Stoneking, Mark; Kayser, Manfred

    2009-08-01

    Eastern Indonesia possesses more linguistic diversity than any other region in Southeast Asia, with both Austronesian (AN) languages that are of East Asian origin, as well as non-Austronesian (NAN) languages of likely Melanesian origin. Here, we investigated the genetic history of human populations from seven eastern Indonesian islands, including AN and NAN speakers, as well as the relationship between languages and genes, by means of nonrecombining Y-chromosomal (NRY) and mitochondrial DNA (mtDNA) analysis. We found that the eastern Indonesian gene pool consists of East Asian as well as Melanesian components, as might be expected based on linguistic evidence, but also harbors putative indigenous eastern Indonesian signatures that perhaps reflect the initial occupation of the Wallacea by aboriginal hunter-gatherers already in Palaeolithic times. Furthermore, both NRY and mtDNA data showed a complete lack of correlation between linguistic and genetic relationships, most likely reflecting genetic admixture and/or language shift. In addition, we noted a small fraction of the NRY and mtDNA data shared between eastern Indonesians and Australian Aborigines likely reflecting an ancient link between Asia and Australia. Our data thus provide insights into the complex genetic ancestry history of eastern Indonesian islanders characterized by several admixture episodes and demonstrate a clear example of the lack of the often-assumed correlation between the genes and languages of human populations. PMID:19414523

  1. Improvement Of Sub-Grade Soil Properties Using Admixture Quarry Dust And Woven Geo-Textile

    Directory of Open Access Journals (Sweden)

    G. Priya Vasudha

    2015-08-01

    Full Text Available Abstract The important factor for design and construction of pavement is the behavior of underlying sub-grade. Large deformations in the sub-grade will lead to a continuous deterioration of the paved surface. As the sub-grade soil is too weak to bear the load engineering solutions such as geo reinforcement using geo-synthetics are additives which are earlier used in sub-grade improvement and such experimental study is carried by pervious authors. This paper deals with the sub-grade improvement using geo-textile as a reinforcement sheet and quarry dust as admixtures. In order to increase the strength of the sub-grade the quarry dust is varied with different percentages i.e. 0 5 10 15 20 and 25. In this study Proctors compaction tests and CBR soaked and unsoaked tests are conducted on locally available soil with reinforced material and with admixture. For this study it is identified that the engineering properties of the soil is improved in all conditions. The soil with quarry dust at optimum value is 20 has CBR soaked value is obtained 6.83 and unsoaked value is obtained 7.02 is increased when compared with conventionally soil. The soil quarry dust at optimum value is at 20 and Geo-textile has CBR soaked value is 6.59 and unsoaked value is 8.95 is increased when compared with conventionally soil and soil with quarry dust.

  2. Preparation of High Impermeable and Crack-resistance Chemical Admixture and Its Mechanism

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A kind of high impermeable and crack-resistance chemical admixture (HICRCA) was prepared, which is a compound chemical admixture composed of an expansion ingredient,density ingredient, and organic hydrophobic poreblocking ingredient. The results of the experiments indicate that the addition of HICRCA improves mortar and concrete in the following performances:(1) perfect workability: slump is more than 22cm, the slump after 3h is about 16cm; (2)high impermeability:for the mortar,the pervious height under a water pressure of 1.5MPa is 1.5cm,for the concrete, the pervious height under a water pressure of 5.0MPa is 2.2cm;(3)high crack-resistance:there is a micro-expansion at the age of 90d;(4)high compressivestrength:compared with the controlled concrete,the compressive strengths at the age of 3d and 28d are improved by 66.4% and 62.0%, respectively.At the same time,the effects of different curing condition on mortar and concrete expansive and shrinkage performance were studied.In addition,the impermeable and crack-resistance mechanism was investigated in the present paper.

  3. Growth and characterization of pure and semiorganic nonlinear optical Lithium Sulphate admixtured l-alanine crystal

    Science.gov (United States)

    Vela, T.; Selvarajan, P.; Freeda, T. H.; Balasubramanian, K.

    2013-04-01

    Lithium sulphate admixtured l-alanine (LSLA) salt was synthesized and the solubility of the commercially available l-alanine and the synthesized LSLA sample was determined in de-ionized water at various temperatures. In accordance with the solubility data, the saturated aqueous solutions of l-alanine and lithium admixtured l-alanine were prepared separately and the single crystals of the samples were grown by the solution method with a slow evaporation technique. Studying single x-ray diffraction shows that pure and LSLA crystal belong to the orthorhombic system with a non-centrosymmetric space group P212121. Using the powder x-ray diffraction study, the crystallinity of the grown crystals is confirmed and the diffraction peaks are indexed. The various functional groups present in the pure and LSLA crystal are elucidated from Fourier transform infrared spectroscopy study. UV-visible transmittance is recorded to study the optical transmittance range for the grown crystals. The powder second harmonic generation test confirms the nonlinear optical property of the grown crystals. From the microhardness test, the hardness of the grown crystals is estimated. The dielectric behaviour, such as the dielectric constant and the loss of the sample, are measured as a function of temperature and frequency. The ac conductivity of the grown crystals is also studied and the activation energy is calculated.

  4. Growth and characterization of pure and semiorganic nonlinear optical Lithium Sulphate admixtured l-alanine crystal

    International Nuclear Information System (INIS)

    Lithium sulphate admixtured l-alanine (LSLA) salt was synthesized and the solubility of the commercially available l-alanine and the synthesized LSLA sample was determined in de-ionized water at various temperatures. In accordance with the solubility data, the saturated aqueous solutions of l-alanine and lithium admixtured l-alanine were prepared separately and the single crystals of the samples were grown by the solution method with a slow evaporation technique. Studying single x-ray diffraction shows that pure and LSLA crystal belong to the orthorhombic system with a non-centrosymmetric space group P212121. Using the powder x-ray diffraction study, the crystallinity of the grown crystals is confirmed and the diffraction peaks are indexed. The various functional groups present in the pure and LSLA crystal are elucidated from Fourier transform infrared spectroscopy study. UV–visible transmittance is recorded to study the optical transmittance range for the grown crystals. The powder second harmonic generation test confirms the nonlinear optical property of the grown crystals. From the microhardness test, the hardness of the grown crystals is estimated. The dielectric behaviour, such as the dielectric constant and the loss of the sample, are measured as a function of temperature and frequency. The ac conductivity of the grown crystals is also studied and the activation energy is calculated. (paper)

  5. EFFICIENT NANO-SCALE ADMIXTURE FOR FOAM STABILITY IMPROVEMENT OF CELLULAR CONCRETES

    Directory of Open Access Journals (Sweden)

    Grishina Аnna Nikolaevna

    2012-10-01

    Full Text Available The authors present their methodology of synthesis of a nano-scale additive designated for the stabilization of synthetic foaming agents. The nano-scale admixture is composed of iron hydroxide (III sol and aqueous sodium hydro silicates (water glass. Besides the above method, the topological structural model of the nano-scale additive is proposed. The additive stability was assessed upon its one-day storage (with the foaming agent added, and the assessment data are provided in the article. The authors have discovered that it is advisable to use an iron chloride solution in the concentration of 1 % to manufacture the iron hydroxide (III sol. The authors have also discovered that the rate of jellification goes up in the process of injecting the foaming agent into the foam that contains the nano-scale admixture developed by the authors. Dependence between the amount of sodium hydro silicate and the viscosity of the system composed of the water glass and the sol of iron hydroxide (III is examined in detail. The authors have identified that the average water glass viscosity curve demonstrates an extreme nature. The additive is used for the stabilization of the foam generated by synthetic foaming agents. The injection of the proposed additive improves foam stability. It is noteworthy that this positive result is free from any negative side effects.

  6. Head CT scan

    Science.gov (United States)

    Brain CT; Cranial CT; CT scan - skull; CT scan - head; CT scan - orbits; CT scan - sinuses; Computed tomography - cranial ... The x-rays produced by the CT scan are painless. Some people may ... hard table. Contrast given through a vein may cause a: Slight ...

  7. RBC nuclear scan

    Science.gov (United States)

    An RBC nuclear scan uses small amounts of radioactive material to mark (tag) red blood cells (RBCs). Your body is then ... scanner does not give off any radiation. Most nuclear scans (including an RBC scan) are not recommended ...

  8. Heart PET scan

    Science.gov (United States)

    ... nuclear medicine scan; Heart positron emission tomography; Myocardial PET scan ... A PET scan requires a small amount of radioactive material (tracer). This tracer is given through a vein (IV), ...

  9. Coronary Calcium Scan

    Science.gov (United States)

    ... the NHLBI on Twitter. What Is a Coronary Calcium Scan? A coronary calcium scan is a test ... you have calcifications in your coronary arteries. Coronary Calcium Scan Figure A shows the position of the ...

  10. Scan BIST with biased scan test signals

    Institute of Scientific and Technical Information of China (English)

    XIANG Dong; CHEN MingJing; SUN JiaGuang

    2008-01-01

    The conventional test-per-scan built-in self-test (BIST) scheme needs a number of shift cycles followed by one capture cycle.Fault effects received by the scan flip-flops are shifted out while shifting in the next test vector like scan testing.Unlike deterministic testing,it is unnecessary to apply a complete test vector to the scan chains.A new scan-based BIST scheme is proposed by properly controlling the test signals of the scan chains,Different biased random values are assigned to the test signals of scan flip-flops in separate scan chains.Capture cycles can be inserted at any clock cycle if necessary.A new testability estimation procedure according to the proposed testing scheme is presented.A greedy procedure is proposed to select a weight for each scan chain.Experimental results show that the proposed method can improve test effectiveness of scan-based BIST greatly,and most circuits can obtain complete fault coverage or very close to complete fault coverage.

  11. Limit on a right-handed admixture to the weak b→c current from semileptonic decays

    International Nuclear Information System (INIS)

    We determine an upper bound for a possible right-handed b→c quark current admixture in semileptonic B→Xcl-ν decays from a simultaneous fit to moments of the lepton-energy and hadronic-mass distribution measured as a function of the lower limit on the lepton energy, using data measured by the BABAR detector. The right-handed admixture is parametrized by a new parameter cR as coefficient of computed moments with right-handed quark current. For the standard-model part we use the prediction of the heavy-quark expansion up to order 1/mb3 and perturbative corrections and for the right-handed contribution only up to order 1/mb2 and perturbative corrections. We find cR'=0.05-0.50+0.33 in agreement with the standard-model prediction of zero. Additionally, we give a constraint on a possible right-handed admixture from exclusive decays, which is with a value of cR'=0.01±0.03 more restrictive than our value from the inclusive fit. The difference in |Vcb| between the inclusive and exclusive extraction is only slightly reduced when allowing for a right-handed admixture in the range of cR'=0.01±0.03.

  12. Secondary contact and admixture between independently invading populations of the western corn rootworm, Diabrotica virgifera virgifera in Europe.

    Directory of Open Access Journals (Sweden)

    Gérald Bermond

    Full Text Available The western corn rootworm, Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae, is one of the most destructive pests of corn in North America and is currently invading Europe. The two major invasive outbreaks of rootworm in Europe have occurred, in North-West Italy and in Central and South-Eastern Europe. These two outbreaks originated from independent introductions from North America. Secondary contact probably occurred in North Italy between these two outbreaks, in 2008. We used 13 microsatellite markers to conduct a population genetics study, to demonstrate that this geographic contact resulted in a zone of admixture in the Italian region of Veneto. We show that i genetic variation is greater in the contact zone than in the parental outbreaks; ii several signs of admixture were detected in some Venetian samples, in a bayesian analysis of the population structure and in an approximate bayesian computation analysis of historical scenarios and, finally, iii allelic frequency clines were observed at microsatellite loci. The contact between the invasive outbreaks in North-West Italy and Central and South-Eastern Europe resulted in a zone of admixture, with particular characteristics. The evolutionary implications of the existence of a zone of admixture in Northern Italy and their possible impact on the invasion success of the western corn rootworm are discussed.

  13. The Effect of a Plasticizing Admixture on the Properties of Hardened Concrete

    Directory of Open Access Journals (Sweden)

    Anastasija Abasova

    2012-11-01

    Full Text Available Concrete is material obtained mixing matrix material, coarse and small aggregates and water along with additives acquiring necessary properties of hardening. The quality and properties of raw material used for manufacturing concrete, V/C ratio and the uniformity of the compaction of the mixture lead to the fundamental properties of concrete. The compressive strength of concrete is one of the most important properties of concrete. The article deals with the impact of plasticizers on the structural properties of concrete choosing an optimal content of additives. Concrete plasticizers increasing the content of additive increase the strength of samples, the density and ultrasonic pulse of velocity and decrease absorption. Test results have revealed that a plasticizing admixture under dosing or overdosing can reduce the properties of concrete.

  14. Development of admixture to produce pumping-concrete with large amount of ordinary-fineness-slag

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y.; Sun, Z.; Zhang, G. [Tongji Univ., College of Materials Science and Enginnering, Shanghai (China); Zhou, A. W. Z.; Liu, Q.; Chen, K. [HI CON Huaxi Concrete Admixtures Co., Ltd., Sichuan (China)

    1998-12-31

    A special admixture - WZ - which can be applied to prepare pumping-concrete with large amount of OFS to solve the strength problem of slag was developed. The activating components of WZ include no Cl or SO{sub 4}{sup 2}. As a result, the addition of WZ is an effective way to make use of industrial waste, reduce the cost of concrete, improve its durability, and protect the environment at the same time. Impermeability, freezing-thawing resistance, chemical corrosion resistance and resistance to carbonation were found to be superior to concrete of the same strength using only cement as bonding material. Dry shrinking ratio was less than the shrinking ratio for ordinary concrete. 6 refs., 8 tabs., 1 fig.

  15. Probing background ionization: Positive streamers with varying pulse repetition rate and with a radioactive admixture

    CERN Document Server

    Nijdam, S; van Veldhuizen, E M; Ebert, U

    2011-01-01

    Positive streamers need a source of free electrons ahead of them to propagate. A streamer can supply these electrons by itself through photo-ionization, or the electrons can be present due to external background ionization. Here we investigate the effects of background ionization on streamer propagation and morphology by changing the gas composition and the repetition rate of the voltage pulses, and by adding a small amount of radioactive Krypton 85. We find that the general morphology of a positive streamer discharge in high purity nitrogen depends on background ionization: at lower background ionization levels the streamers branch more and have a more feather-like appearance. This is observed both when varying the repetition rate and when adding Krypton 85, though side branches are longer with the radioactive admixture. But velocities and minimal diameters of streamers are virtually independent of the background ionization level. In air, the inception cloud breaks up into streamers at a smaller radius when ...

  16. THE EFFECT OF 800 0C ON BOND STRENGTH OF CONCRETE WITH MINERAL ADMIXTURE

    Directory of Open Access Journals (Sweden)

    Ahmet COŞKUN

    2007-03-01

    Full Text Available The effect of high temperature (800 0C on the bond strength between concrete and rebar was investigated. In addition to concrete mixture with only portland cement, concrete mixtures with 10% silica fume and 15 % fly ash replacing cement by weight was prepared. Maximum aggregate size is as 16 mm. The 150×150×150 mm cube specimens were prepared for compressive strength and the 100×200 mm cylinder specimens were prepared for bond strength. The specimens were cured in air for 270 days after curing in water 20±2 °C for 28 days. After being heated to temperatures of 800 ºC, compressive strength and bond strength of concrete were tested. The results showed that specimens with silica fume always gave the highest values followed by those as specimens with fly ash and specimens without mineral admixtures irrespective of type and age of concrete and test methods.

  17. Influence of Shrinkage-Reducing Admixtures on the Development of Plastic Shrinkage Cracks

    DEFF Research Database (Denmark)

    Lura, Pietro; Pease, Bradley Justin; Mazzotta, Guy;

    2007-01-01

    The term plastic shrinkage cracking is generally used to describe cracks that form between the time when concrete is placed and the time when concrete sets. This paper discusses how the evaporation of water causes concave menisci to form on the surface of fresh concrete. These menisci cause both...... settlement of the concrete and tensile stress development in the surface of the concrete, which increase the potential for development of plastic shrinkage cracks. Specifically, this paper studies the development of plastic shrinkage cracks in mortars containing a commercially available shrinkage......-reducing admixture (SRA). Mortars containing SRA show fewer and narrower plastic shrinkage cracks than plain mortars when exposed to the same environmental conditions. It is proposed that the lower surface tension of the pore fluid in the mortars containing SRA results in less evaporation, reduced settlement...

  18. Plastic shrinkage of mortars with shrinkage reducing admixture and lightweight aggregates studied by neutron tomography

    Energy Technology Data Exchange (ETDEWEB)

    Wyrzykowski, Mateusz, E-mail: mateusz.wyrzykowski@empa.ch [Empa, Swiss Federal Laboratories for Materials Science and Technology, Concrete and Construction Chemistry Laboratory, Dübendorf (Switzerland); Lodz University of Technology, Department of Building Physics and Building Materials, Lodz (Poland); Trtik, Pavel [Paul Scherrer Institute, Laboratory for Neutron Scattering and Imaging, Villigen (Switzerland); Empa, Swiss Federal Laboratories for Materials Science and Technology, Concrete and Construction Chemistry Laboratory, Dübendorf (Switzerland); Münch, Beat [Empa, Swiss Federal Laboratories for Materials Science and Technology, Concrete and Construction Chemistry Laboratory, Dübendorf (Switzerland); Weiss, Jason [Purdue University, School of Civil Engineering, West Lafayette (United States); Vontobel, Peter [Paul Scherrer Institute, Laboratory for Neutron Scattering and Imaging, Villigen (Switzerland); Lura, Pietro [Empa, Swiss Federal Laboratories for Materials Science and Technology, Concrete and Construction Chemistry Laboratory, Dübendorf (Switzerland); ETH Zurich, Institute for Building Materials (IfB), Zurich (Switzerland)

    2015-07-15

    Water transport in fresh, highly permeable concrete and rapid water evaporation from the concrete surface during the first few hours after placement are the key parameters influencing plastic shrinkage cracking. In this work, neutron tomography was used to determine both the water loss from the concrete surface due to evaporation and the redistribution of fluid that occurs in fresh mortars exposed to external drying. In addition to the reference mortar with a water to cement ratio (w/c) of 0.30, a mortar with the addition of pre-wetted lightweight aggregates (LWA) and a mortar with a shrinkage reducing admixture (SRA) were tested. The addition of SRA reduced the evaporation rate from the mortar at the initial stages of drying and reduced the total water loss. The pre-wetted LWA released a large part of the absorbed water as a consequence of capillary pressure developing in the fresh mortar due to evaporation.

  19. An experimental study of the combustion characteristics of groundnut shell and waste paper admixture briquettes

    Directory of Open Access Journals (Sweden)

    O. A. Oyelaran

    2015-12-01

    Full Text Available The study was undertaken to assess the heat released of briquettes produced from waste paper and groundnut shell admixture in five mixing ratios (90:10; 80:20; 70:30; 60:40; and 50:50. The briquettes were prepared on an existing motorized briquetting machine. The suitability of briquetted fuel as domestic fuel was studied in terms of flame propagation, afterglow, calorific value, and utilized heat, after sun drying the prepared briquettes for nineteen (19 days. The results of propagation rate and afterglow obtained for all the six compositions are satisfactory they range between 0.13 to 0.14 and 365 to 380 respectively. These energy values obtained for the whole samples are sufficient enough to produce heat required for household cooking and small scale industrial cottage applications. Finally it was observed that composition variation affects the properties of the briquettes.

  20. Effect of Admixtures on the Yield Stresses of Cement Pastes under High Hydrostatic Pressures

    Directory of Open Access Journals (Sweden)

    Hong Jae Yim

    2016-03-01

    Full Text Available When cement-based materials are transported at a construction site, they undergo high pressures during the pumping process. The rheological properties of the materials under such high pressures are unknown, and estimating the workability of the materials after pumping is a complex problem. Among various influential factors on the rheology of concrete, this study investigated the effect of mineral and chemical admixtures on the high-pressure rheology. A rheometer was fabricated that could measure the rheological properties while maintaining a high pressure to simulate the pumping process. The effects of superplasticizer, silica fume, nanoclay, fly ash, or ground granulated blast furnace slag were investigated when mixed with two control cement pastes. The water-to-cement ratios were 0.35 and 0.50.

  1. Some radiation-optical properties of fluorphlogopite with admixture of vanadium

    Energy Technology Data Exchange (ETDEWEB)

    Avesov, A.D.; Gasanov, E.M. (AN Uzbekskoj SSR, Tashkent. Inst. Yadernoj Fiziki)

    1982-10-16

    A study is reported on crystals of synthetic mica fluorphlogopite KMg/sub 3/(AlSi/sub 3/O/sub 10/)F/sub 2/ with vanadium admixtures of 0.5 to 5%. Optical absorption spectra of fluorphlogopite samples neutron irradiated with doses of 10/sup 18/, 5 x 10/sup 18/, and 2.5 x 10/sup 19/ cm/sup -2/ show additional absorption bands at 300 to 330 and 560 nm. Most clearly these bands are observed in samples having small amounts of V/sub 2/O/sub 5/. It was concluded that under neutron irradiation in vanadium fluorphlogopite substitution of F/sup -/ anions by O/sup 2 -/ anions takes place, coupled with a valence transition V/sup 2 +/ ..-->.. V/sup 3 +/ upon growing irradiation dose.

  2. Plastic shrinkage of mortars with shrinkage reducing admixture and lightweight aggregates studied by neutron tomography

    International Nuclear Information System (INIS)

    Water transport in fresh, highly permeable concrete and rapid water evaporation from the concrete surface during the first few hours after placement are the key parameters influencing plastic shrinkage cracking. In this work, neutron tomography was used to determine both the water loss from the concrete surface due to evaporation and the redistribution of fluid that occurs in fresh mortars exposed to external drying. In addition to the reference mortar with a water to cement ratio (w/c) of 0.30, a mortar with the addition of pre-wetted lightweight aggregates (LWA) and a mortar with a shrinkage reducing admixture (SRA) were tested. The addition of SRA reduced the evaporation rate from the mortar at the initial stages of drying and reduced the total water loss. The pre-wetted LWA released a large part of the absorbed water as a consequence of capillary pressure developing in the fresh mortar due to evaporation

  3. Influence of Mineral Admixtures on the Permeability of Lightweight Aggregate Concrete

    Institute of Scientific and Technical Information of China (English)

    WANG Fazhou; HU Shuguang; DING Qingjun; PENG yanzhou

    2005-01-01

    The permeability of lightweight aggregate concrete was studied. Some efforts were taken to increase the resistance of lightweight aggregate concrete (LC) to water penetration by using the mineral admixtures of fly ash, granulated blast furnace slag or silica fume. Accelerated chloride penetrability test and liquid atmosphere press method were used to study the anti-permeability of lightweight aggregate concrete. The experimental results show that fly ash, granulated blast furnace slag and silica fume can decrease the permeability of lightweight aggregate concrete, but the effect of granulated blast furnace slag is poor. According to the SEM and pore structure analyzing results,an interface self-reinforcing effect model was presented and the reinforced mechanism of mineral mixture on LC was discussed according to the model described by authors.

  4. Global genetic variation at OAS1 provides evidence of archaic admixture in Melanesian populations.

    Science.gov (United States)

    Mendez, Fernando L; Watkins, Joseph C; Hammer, Michael F

    2012-06-01

    Recent analysis of DNA extracted from two Eurasian forms of archaic human shows that more genetic variants are shared with humans currently living in Eurasia than with anatomically modern humans in sub-Saharan Africa. Although these genome-wide average measures of genetic similarity are consistent with the hypothesis of archaic admixture in Eurasia, analyses of individual loci exhibiting the signal of archaic introgression are needed to test alternative hypotheses and investigate the admixture process. Here, we provide a detailed sequence analysis of the innate immune gene OAS1, a locus with a divergent Melanesian haplotype that is very similar to the Denisova sequence from the Altai region of Siberia. We resequenced a 7-kb region encompassing the OAS1 gene in 88 individuals from six Old World populations (San, Biaka, Mandenka, French Basque, Han Chinese, and Papua New Guineans) and discovered previously unknown and ancient genetic variation. The 5' region of this gene has unusual patterns of diversity, including 1) higher levels of nucleotide diversity in Papuans than in sub-Saharan Africans, 2) very deep ancestry with an estimated time to the most recent common ancestor of >3 myr, and 3) a basal branching pattern with Papuan individuals on either side of the rooted network. A global geographic survey of >1,500 individuals showed that the divergent Papuan haplotype is nearly restricted to populations from eastern Indonesia and Melanesia. Polymorphic sites within this haplotype are shared with the draft Denisova genome over a span of ∼90 kb and are associated with an extended block of linkage disequilibrium, supporting the hypothesis that this haplotype introgressed from an archaic source that likely lived in Eurasia. PMID:22319157

  5. Genetic structure of the population of Cabo Verde (west Africa): evidence of substantial European admixture.

    Science.gov (United States)

    Parra, E J; Ribeiro, J C; Caeiro, J L; Riveiro, A

    1995-08-01

    The population of Cabo Verde was founded in the fifteenth century (1462), on the basis of slaves brought from the West African coast and a few Europeans, mainly from Portugal. The polymorphism of six red cell enzymes (ADA, AK1, ALAD, ESD, GLO1, and PGD) and ten plasma proteins (AHSG, BF, F13A, F13B, GC, HP, ORM, PLG, TBG, and TF) was studied in a sample of 268 individuals from Cabo Verde (West Africa). There is no statistical evidence of genetic heterogeneity between the two groups of islands which constitute the archipelago, Barlavento and Sotavento. The gene frequency distribution observed in Cabo Verde differs, in many markers, from that of West African populations, suggesting an important European influence. The proportion of Caucasian genes in the population of Cabo Verde has been calculated to be M = 0.3634 +/- 0.0510, and the considerable dispersion of the locus-specific admixture estimates seems to indicate random drift has also played a role in the evolution of the allele frequencies in the archipelago. Partition of the variance of the mean estimate in evolutionary and sampling variance shows the evolutionary variance is more than ten times higher than the sampling variance. When dendrograms are constructed on the basis of different genetic distances, the population of Cabo Verde clusters with Afro-Americans, forming a different group from the populations of the African continent. This is interpreted as a consequence of the importance of Caucasian admixture both in Afro-Americans and in the population of Cabo Verde. PMID:7485435

  6. No clear effect of admixture between two European invading outbreaks of Diabrotica virgifera virgifera in natura.

    Directory of Open Access Journals (Sweden)

    Gérald Bermond

    Full Text Available In this study, we challenged the hypothesis that admixture may have had a positive impact in the context of the European invasion of the western corn rootworm (WCR, Diabrotica virgifera virgifera, LeConte. This beetle was introduced in Europe from the USA several times since the 1980's. The multiple introductions of this major pest of cultivated corn led to the formation of two major outbreaks in North Western (NW Italy and in Central and South Eastern (CSE Europe that eventually merged into a secondary contact zone where insects from both outbreaks interbreed. We collected about 600 insects from this contact zone and genotyped them using 13 microsatellite markers. Three types of information were obtained from the collected individuals: (i their survival under starvation; (ii their admixed status, determined through a Bayesian method of genetic clustering and (iii their mating probability, studied via the detection, isolation and genotyping of sperm in female spermathecae. Twenty six % and 12% of the individuals were assigned to the NW Italy or the CSE Europe parental types, respectively, and 23% and 39% to the F1 and backcross hybrid types, respectively. Globally, our results do not reveal any significant impact of the admixed status on the mating probability and on the choice of mating partners. However the admixed status had a sex- and sampling site-dependent effect on survival in adults under starvation. In addition sex had an effect on survival, with mortality hazard about 3 times larger in males than in females. The consequences of these findings for the evolution of the admixture zone of northern Italy are discussed.

  7. Origin and dynamics of admixture in Brazilians and its effect on the pattern of deleterious mutations.

    Science.gov (United States)

    Kehdy, Fernanda S G; Gouveia, Mateus H; Machado, Moara; Magalhães, Wagner C S; Horimoto, Andrea R; Horta, Bernardo L; Moreira, Rennan G; Leal, Thiago P; Scliar, Marilia O; Soares-Souza, Giordano B; Rodrigues-Soares, Fernanda; Araújo, Gilderlanio S; Zamudio, Roxana; Sant Anna, Hanaisa P; Santos, Hadassa C; Duarte, Nubia E; Fiaccone, Rosemeire L; Figueiredo, Camila A; Silva, Thiago M; Costa, Gustavo N O; Beleza, Sandra; Berg, Douglas E; Cabrera, Lilia; Debortoli, Guilherme; Duarte, Denise; Ghirotto, Silvia; Gilman, Robert H; Gonçalves, Vanessa F; Marrero, Andrea R; Muniz, Yara C; Weissensteiner, Hansi; Yeager, Meredith; Rodrigues, Laura C; Barreto, Mauricio L; Lima-Costa, M Fernanda; Pereira, Alexandre C; Rodrigues, Maíra R; Tarazona-Santos, Eduardo

    2015-07-14

    While South Americans are underrepresented in human genomic diversity studies, Brazil has been a classical model for population genetics studies on admixture. We present the results of the EPIGEN Brazil Initiative, the most comprehensive up-to-date genomic analysis of any Latin-American population. A population-based genome-wide analysis of 6,487 individuals was performed in the context of worldwide genomic diversity to elucidate how ancestry, kinship, and inbreeding interact in three populations with different histories from the Northeast (African ancestry: 50%), Southeast, and South (both with European ancestry >70%) of Brazil. We showed that ancestry-positive assortative mating permeated Brazilian history. We traced European ancestry in the Southeast/South to a wider European/Middle Eastern region with respect to the Northeast, where ancestry seems restricted to Iberia. By developing an approximate Bayesian computation framework, we infer more recent European immigration to the Southeast/South than to the Northeast. Also, the observed low Native-American ancestry (6-8%) was mostly introduced in different regions of Brazil soon after the European Conquest. We broadened our understanding of the African diaspora, the major destination of which was Brazil, by revealing that Brazilians display two within-Africa ancestry components: one associated with non-Bantu/western Africans (more evident in the Northeast and African Americans) and one associated with Bantu/eastern Africans (more present in the Southeast/South). Furthermore, the whole-genome analysis of 30 individuals (42-fold deep coverage) shows that continental admixture rather than local post-Columbian history is the main and complex determinant of the individual amount of deleterious genotypes. PMID:26124090

  8. Genetic origin, admixture, and asymmetry in maternal and paternal human lineages in Cuba

    Directory of Open Access Journals (Sweden)

    Martínez-Fuentes Antonio

    2008-07-01

    Full Text Available Abstract Background Before the arrival of Europeans to Cuba, the island was inhabited by two Native American groups, the Tainos and the Ciboneys. Most of the present archaeological, linguistic and ancient DNA evidence indicates a South American origin for these populations. In colonial times, Cuban Native American people were replaced by European settlers and slaves from Africa. It is still unknown however, to what extent their genetic pool intermingled with and was 'diluted' by the arrival of newcomers. In order to investigate the demographic processes that gave rise to the current Cuban population, we analyzed the hypervariable region I (HVS-I and five single nucleotide polymorphisms (SNPs in the mitochondrial DNA (mtDNA coding region in 245 individuals, and 40 Y-chromosome SNPs in 132 male individuals. Results The Native American contribution to present-day Cubans accounted for 33% of the maternal lineages, whereas Africa and Eurasia contributed 45% and 22% of the lineages, respectively. This Native American substrate in Cuba cannot be traced back to a single origin within the American continent, as previously suggested by ancient DNA analyses. Strikingly, no Native American lineages were found for the Y-chromosome, for which the Eurasian and African contributions were around 80% and 20%, respectively. Conclusion While the ancestral Native American substrate is still appreciable in the maternal lineages, the extensive process of population admixture in Cuba has left no trace of the paternal Native American lineages, mirroring the strong sexual bias in the admixture processes taking place during colonial times.

  9. Multilocus Bayesian Estimates of Intra-Oceanic Genetic Differentiation, Connectivity, and Admixture in Atlantic Swordfish (Xiphias gladius L..

    Directory of Open Access Journals (Sweden)

    Brad L Smith

    Full Text Available Previous genetic studies of Atlantic swordfish (Xiphias gladius L. revealed significant differentiation among Mediterranean, North Atlantic and South Atlantic populations using both mitochondrial and nuclear DNA data. However, limitations in geographic sampling coverage, and the use of single loci, precluded an accurate placement of boundaries and of estimates of admixture. In this study, we present multilocus analyses of 26 single nucleotide polymorphisms (SNPs within 10 nuclear genes to estimate population differentiation and admixture based on the characterization of 774 individuals representing North Atlantic, South Atlantic, and Mediterranean swordfish populations. Pairwise FST values, AMOVA, PCoA, and Bayesian individual assignments support the differentiation of swordfish inhabiting these three basins, but not the current placement of the boundaries that separate them. Specifically, the range of the South Atlantic population extends beyond 5°N management boundary to 20°N-25°N from 45°W. Likewise the Mediterranean population extends beyond the current management boundary at the Strait of Gibraltar to approximately 10°W. Further, admixture zones, characterized by asymmetric contributions of adjacent populations within samples, are confined to the Northeast Atlantic. While South Atlantic and Mediterranean migrants were identified within these Northeast Atlantic admixture zones no North Atlantic migrants were identified respectively in these two neighboring basins. Owing to both, the characterization of larger number of loci and a more ample spatial sampling coverage, it was possible to provide a finer resolution of the boundaries separating Atlantic swordfish populations than previous studies. Finally, the patterns of population structure and admixture are discussed in the light of the reproductive biology, the known patterns of dispersal, and oceanographic features that may act as barriers to gene flow to Atlantic swordfish.

  10. Aerial Photography and Imagery, Ortho-Corrected, 1961 Aerial photography maps that have been scanned and georefernced for use within Madison County's GIS., Published in 1961, 1:7200 (1in=600ft) scale, Madison County Council of Governments.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Aerial Photography and Imagery, Ortho-Corrected dataset, published at 1:7200 (1in=600ft) scale, was produced all or in part from Hardcopy Maps information as...

  11. A Generic Procedure for the Assessment of the Effect of Concrete Admixtures on the Sorption of Radionuclides on Cement: Concept and Selected Results

    Energy Technology Data Exchange (ETDEWEB)

    Glaus, M.A.; Laube, A.; Van Loon, L.R

    2004-03-01

    A screening procedure is proposed for the assessment of the effect of concrete admixtures on the sorption of radionuclides by cement. The procedure is both broad and generic, and can thus be used as input for the assessment of concrete admixtures which might be used in the future. The experimental feasibility and significance of the screening procedure are tested using selected concrete admixtures: i.e. sulfonated naphthalene-formaldehyde condensates, lignosulfonates, and a plasticiser used at PSI for waste conditioning. The effect of these on the sorption properties of Ni(II), Eu(III) and Th(IV) in cement is investigated using crushed Hardened Cement Paste (HCP), as well as cement pastes prepared in the presence of these admixtures. Strongly adverse effects on the sorption of the radionuclides tested are observed only in single cases, and under extreme conditions: i.e. at high ratios of concrete admixtures to HCP, and at low ratios of HCP to cement pore water. Under realistic conditions, both radionuclide sorption and the sorption of isosaccharinic acid (a strong complexant produced in cement-conditioned wastes containing cellulose) remain unaffected by the presence of concrete admixtures, which can be explained by the sorption of them onto the HCP. The pore-water concentrations of the concrete admixtures tested are thereby reduced to levels at which the formation of radionuclide complexes is no longer of importance. Further, the Langmuir sorption model, proposed for the sorption of concrete admixtures on HCP, suggests that the HCP surface does not become saturated, at least for those concrete admixtures tested. (author)

  12. A Generic Procedure for the Assessment of the Effect of Concrete Admixtures on the Sorption of Radionuclides on Cement: Concept and Selected Results

    International Nuclear Information System (INIS)

    A screening procedure is proposed for the assessment of the effect of concrete admixtures on the sorption of radionuclides by cement. The procedure is both broad and generic, and can thus be used as input for the assessment of concrete admixtures which might be used in the future. The experimental feasibility and significance of the screening procedure are tested using selected concrete admixtures: i.e. sulfonated naphthalene-formaldehyde condensates, lignosulfonates, and a plasticiser used at PSI for waste conditioning. The effect of these on the sorption properties of Ni(II), Eu(III) and Th(IV) in cement is investigated using crushed Hardened Cement Paste (HCP), as well as cement pastes prepared in the presence of these admixtures. Strongly adverse effects on the sorption of the radionuclides tested are observed only in single cases, and under extreme conditions: i.e. at high ratios of concrete admixtures to HCP, and at low ratios of HCP to cement pore water. Under realistic conditions, both radionuclide sorption and the sorption of isosaccharinic acid (a strong complexant produced in cement-conditioned wastes containing cellulose) remain unaffected by the presence of concrete admixtures, which can be explained by the sorption of them onto the HCP. The pore-water concentrations of the concrete admixtures tested are thereby reduced to levels at which the formation of radionuclide complexes is no longer of importance. Further, the Langmuir sorption model, proposed for the sorption of concrete admixtures on HCP, suggests that the HCP surface does not become saturated, at least for those concrete admixtures tested. (author)

  13. Scan matching SLAM in underwater environments

    OpenAIRE

    Mallios, Angelos; Ridao Rodríguez, Pere; Ribas Romagós, David; Hernàndez Bes, Emili

    2014-01-01

    This paper proposes a pose-based algorithm to solve the full simultaneous localization and mapping problem for autonomous underwater vehicle (AUV) navigating in unknown and possibly unstructured environments. The proposed method first estimates the local path traveled by the robot while forming the acoustic image (scan) with range data coming from a mono-beam rotating sonar head, providing position estimates for correcting the distortions that the vehicle motion produces in the scans. Then, c...

  14. MULTIPLATFORM APPROACH TO MOBILE LASER SCANNING

    OpenAIRE

    A. Kukko; H. Kaartinen; J. Hyyppä; Chen, Y.

    2012-01-01

    Mobile laser scanning is an emerging technology for capturing three-dimensional information from the surrounding objects. With state of the art sensors the achieved point cloud could capture fine details of the surroundings with good accuracy and effectiveness. Many of the applications deal with the civil engineering purposes in urban areas for traffic and city planning and modelling. In this article we present multiplatform mobile laser scanning solutions for mapping applications that requir...

  15. Admixture analysis of stocked brown trout populations using mapped microsatellite DNA markers: indigenous trout persist in introgressed populations

    DEFF Research Database (Denmark)

    Hansen, Michael Møller; Mensberg, Karen-Lise Dons

    2009-01-01

    , but resolution is low if genetic differentiation is weak. Here, we analyse stocked brown trout populations represented by historical (1943-1956) and contemporary (2000s) samples, where genetic differentiation between wild populations and stocked trout is weak (pair-wise F-ST of 0.047 and 0.053). By...

  16. Rapid Frequency Scan EPR

    OpenAIRE

    Tseitlin, Mark; Rinard, George A.; Quine, Richard W.; Eaton, Sandra S.; Eaton, Gareth R.

    2011-01-01

    In rapid frequency scan EPR with triangular scans, sufficient time must be allowed to insure that the magnetization in the x,y plane decays to baseline at the end of the scan, which typically is about 5 T2 after the spins are excited. To permit relaxation of signals excited toward the extremes of the scan the total scan time required may be much longer than 5 T2. However, with periodic, saw-tooth excitation, the slow-scan EPR spectrum can be recovered by Fourier deconvolution of data recorded...

  17. The “Grep” Command But Not FusionMap, FusionFinder or ChimeraScan Captures the CIC-DUX4 Fusion Gene from Whole Transcriptome Sequencing Data on a Small Round Cell Tumor with t(4;19)(q35;q13)

    OpenAIRE

    Ioannis Panagopoulos; Ludmila Gorunova; Bodil Bjerkehagen; Sverre Heim

    2014-01-01

    Whole transcriptome sequencing was used to study a small round cell tumor in which a t(4;19)(q35;q13) was part of the complex karyotype but where the initial reverse transcriptase PCR (RT-PCR) examination did not detect a CIC-DUX4 fusion transcript previously described as the crucial gene-level outcome of this specific translocation. The RNA sequencing data were analysed using the FusionMap, FusionFinder, and ChimeraScan programs which are specifically designed to identify fusion genes. Fusio...

  18. MR guided spatial normalization of SPECT scans

    International Nuclear Information System (INIS)

    Full text: In SPECT population studies where magnetic resonance (MR) scans are also available, the higher resolution of the MR scans allows for an improved spatial normalization of the SPECT scans. In this approach, the SPECT images are first coregistered to their corresponding MR images by a linear (affine) transformation which is calculated using SPM's mutual information maximization algorithm. Non-linear spatial normalization maps are then computed either directly from the MR scans using SPM's built in spatial normalization algorithm, or, from segmented TI MR images using DARTEL, an advanced diffeomorphism based spatial normalization algorithm. We compare these MR based methods to standard SPECT based spatial normalization for a population of 27 fibromyalgia patients and 25 healthy controls with spin echo T1 scans. We identify significant perfusion deficits in prefrontal white matter in FM patients, with the DARTEL based spatial normalization procedure yielding stronger statistics than the standard SPECT based spatial normalization. (author)

  19. Lung PET scan

    Science.gov (United States)

    Chest PET scan; Lung positron emission tomography; PET - chest; PET - lung; PET - tumor imaging ... A PET scan requires a small amount of tracer. The tracer is given through a vein (IV), usually on ...

  20. RBC nuclear scan

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003835.htm RBC nuclear scan To use the sharing features on this page, please enable JavaScript. An RBC nuclear scan uses small amounts of radioactive material to ...

  1. Atlas of duplex scanning

    International Nuclear Information System (INIS)

    This book presents the first atlas devoted entirely to duplex scanning. It details the uses of this important ''up-and-coming'' diagnostic tool for vascular and general surgeons and radiologists. It also covers scanning of the extremities, as well as the carotoids. The topics also covered are correlative line drawings elaborate and clarify the excellent scan images; the principles of duplex scanning or arteries and veins, techniques, and results; pictures normal anatomy; venous thromboses, arterial occlusion, true and false aneurysms, graft stenoses

  2. Ad Hoc versus Standardized Admixtures for Continuous Infusion Drugs in Neonatal Intensive Care: Cognitive Task Analysis of Safety at the Bedside

    OpenAIRE

    Brannon, Timothy S.

    2006-01-01

    Continuous infusion intravenous (IV) drugs in neonatal intensive care are usually prepared based on patient weight so that the dose is readable as a simple multiple of the infusion pump rate. New safety guidelines propose that hospitals switch to using standardized admixtures of these drugs to prevent calculation errors during ad hoc preparation. Extended hierarchical task analysis suggests that switching to standardized admixtures may lead to more errors in programming the pump at the bedside.

  3. Influence of the calcium concentration in the presence of organic phosphorus on the physicochemical compatibility and stability of all-in-one admixtures for neonatal use

    Directory of Open Access Journals (Sweden)

    de Sousa Valeria

    2009-10-01

    Full Text Available Abstract Background Preterm infants need high amounts of calcium and phosphorus for bone mineralization, which is difficult to obtain with parenteral feeding due to the low solubility of these salts. The objective of this study was to evaluate the physicochemical compatibility of high concentrations of calcium associated with organic phosphate and its influence on the stability of AIO admixtures for neonatal use. Methods Three TPN admixture formulas were prepared in multilayered bags. The calcium content of the admixtures was adjusted to 0, 46.5 or 93 mg/100 ml in the presence of a fixed organic phosphate concentration as well as lipids, amino acids, inorganic salts, glucose, vitamins and oligoelements at pH 5.5. Each admixture was stored at 4°C, 25°C or 37°C and evaluated over a period of 7 days. The physicochemical stability parameters evaluated were visual aspect, pH, sterility, osmolality, peroxide formation, precipitation, and the size of lipid globules. Results Color alterations occurred from the first day on, and reversible lipid film formation from the third day of study for the admixtures stored at 25°C and 37°C. According to the parameters evaluated, the admixtures were stable at 4°C; and none of them presented precipitated particles due to calcium/phosphate incompatibility or lipid globules larger than 5 μm, which is the main parameter currently used to evaluate lipid emulsion stability. The admixtures maintained low peroxide levels and osmolarity was appropriate for parenteral administration. Conclusion The total calcium and calcium/phosphorus ratios studied appeared not to influence the physicochemical compatibility and stability of AIO admixtures.

  4. The ion-selective field-effect transistor application for enzyme analysis of toxic admixtures in aqueous solutions

    Directory of Open Access Journals (Sweden)

    Pavluchenko A. S.

    2010-06-01

    Full Text Available The article describes design and production technology of pH-sensors based on ion-selective field-effect transis-tors (ISFET intended for enzyme analysis of inhibiting admixtures in aqueous solutions, and architecture of the multichannel measuring system built upon the ISFET-sensors. The characteristics of developed prototypes are given and the ways for further improvement of system design, metrological performance and operating parameters are outlined.

  5. Cuba: exploring the history of admixture and the genetic basis of pigmentation using autosomal and uniparental markers.

    Directory of Open Access Journals (Sweden)

    Beatriz Marcheco-Teruel

    2014-07-01

    Full Text Available We carried out an admixture analysis of a sample comprising 1,019 individuals from all the provinces of Cuba. We used a panel of 128 autosomal Ancestry Informative Markers (AIMs to estimate the admixture proportions. We also characterized a number of haplogroup diagnostic markers in the mtDNA and Y-chromosome in order to evaluate admixture using uniparental markers. Finally, we analyzed the association of 16 single nucleotide polymorphisms (SNPs with quantitative estimates of skin pigmentation. In the total sample, the average European, African and Native American contributions as estimated from autosomal AIMs were 72%, 20% and 8%, respectively. The Eastern provinces of Cuba showed relatively higher African and Native American contributions than the Western provinces. In particular, the highest proportion of African ancestry was observed in the provinces of Guantánamo (40% and Santiago de Cuba (39%, and the highest proportion of Native American ancestry in Granma (15%, Holguín (12% and Las Tunas (12%. We found evidence of substantial population stratification in the current Cuban population, emphasizing the need to control for the effects of population stratification in association studies including individuals from Cuba. The results of the analyses of uniparental markers were concordant with those observed in the autosomes. These geographic patterns in admixture proportions are fully consistent with historical and archaeological information. Additionally, we identified a sex-biased pattern in the process of gene flow, with a substantially higher European contribution from the paternal side, and higher Native American and African contributions from the maternal side. This sex-biased contribution was particularly evident for Native American ancestry. Finally, we observed that SNPs located in the genes SLC24A5 and SLC45A2 are strongly associated with melanin levels in the sample.

  6. Effect of Expansive Admixtures on the Shrinkage and Mechanical Properties of High-Performance Fiber-Reinforced Cement Composites

    OpenAIRE

    Won-Chang Choi; Hyun-Do Yun

    2013-01-01

    High-performance fiber-reinforced cement composites (HPFRCCs) are characterized by strain-hardening and multiple cracking during the inelastic deformation process, but they also develop high shrinkage strain. This study investigates the effects of replacing Portland cement with calcium sulfoaluminate-based expansive admixtures (CSA EXAs) to compensate for the shrinkage and associated mechanical behavior of HPFRCCs. Two types of CSA EXA (CSA-K and CSA-J), each with a different chemical composi...

  7. On the use of crystalline admixtures in cement based construction materials: from porosity reducers to promoters of self healing

    Science.gov (United States)

    Ferrara, Liberato; Krelani, Visar; Moretti, Fabio

    2016-08-01

    The project detailed in this paper aims at a thorough characterization of the effects of crystalline admixtures, currently employed as porosity reducing admixtures, on the self-healing capacity of the cementitious composites, i.e. their capacity to completely or partially re-seal cracks and, in case, also exhibit recovery of mechanical properties. The problem has been investigated with reference to both a normal strength concrete (NSC) and a high performance fibre reinforced cementitious composite (HPFRCC). In the latter case, the influence of flow-induced fibre alignment has also been considered in the experimental investigation. With reference to either 3-point (for NSC) or 4-point (for HPFRCC) bending tests performed up to controlled crack opening and up to failure, respectively before and after exposure/conditioning recovery of stiffness and stress bearing capacity has been evaluated to assess the self-healing capacity. In a durability-based design framework, self-healing indices to quantify the recovery of mechanical properties will also be defined. In NSC, crystalline admixtures are able to promote up to 60% of crack sealing even under exposure to open air. In the case of HPFRCCs, which would already feature autogenous healing capacity because of their peculiar mix compositions, the synergy between the dispersed fibre reinforcement and the action of the crystalline admixture has resulted in a likely ‘chemical pre-stressing’ of the same reinforcement, from which the recovery of mechanical performance of the material has greatly benefited, up to levels even higher than the performance of the virgin un-cracked material.

  8. Genetic dating indicates that the Asian–Papuan admixture through Eastern Indonesia corresponds to the Austronesian expansion

    OpenAIRE

    Xu, Shuhua; Pugach, Irina; Stoneking, Mark; Kayser, Manfred; Jin, Li

    2012-01-01

    Although the Austronesian expansion had a major impact on the languages of Island Southeast Asia, controversy still exists over the genetic impact of this expansion. The coexistence of both Asian and Papuan genetic ancestry in Eastern Indonesia provides a unique opportunity to address this issue. Here, we estimate recombination breakpoints in admixed genomes based on genome-wide SNP data and date the genetic admixture between populations of Asian vs. Papuan ancestry in Eastern Indonesia. Anal...

  9. Nuclear Species-Diagnostic SNP Markers Mined from 454 Amplicon Sequencing Reveal Admixture Genomic Structure of Modern Citrus Varieties

    Science.gov (United States)

    Curk, Franck; Ancillo, Gema; Ollitrault, Frédérique; Perrier, Xavier; Jacquemoud-Collet, Jean-Pierre; Garcia-Lor, Andres; Navarro, Luis; Ollitrault, Patrick

    2015-01-01

    Most cultivated Citrus species originated from interspecific hybridisation between four ancestral taxa (C. reticulata, C. maxima, C. medica, and C. micrantha) with limited further interspecific recombination due to vegetative propagation. This evolution resulted in admixture genomes with frequent interspecific heterozygosity. Moreover, a major part of the phenotypic diversity of edible citrus results from the initial differentiation between these taxa. Deciphering the phylogenomic structure of citrus germplasm is therefore essential for an efficient utilization of citrus biodiversity in breeding schemes. The objective of this work was to develop a set of species-diagnostic single nucleotide polymorphism (SNP) markers for the four Citrus ancestral taxa covering the nine chromosomes, and to use these markers to infer the phylogenomic structure of secondary species and modern cultivars. Species-diagnostic SNPs were mined from 454 amplicon sequencing of 57 gene fragments from 26 genotypes of the four basic taxa. Of the 1,053 SNPs mined from 28,507 kb sequence, 273 were found to be highly diagnostic for a single basic taxon. Species-diagnostic SNP markers (105) were used to analyse the admixture structure of varieties and rootstocks. This revealed C. maxima introgressions in most of the old and in all recent selections of mandarins, and suggested that C. reticulata × C. maxima reticulation and introgression processes were important in edible mandarin domestication. The large range of phylogenomic constitutions between C. reticulata and C. maxima revealed in mandarins, tangelos, tangors, sweet oranges, sour oranges, grapefruits, and orangelos is favourable for genetic association studies based on phylogenomic structures of the germplasm. Inferred admixture structures were in agreement with previous hypotheses regarding the origin of several secondary species and also revealed the probable origin of several acid citrus varieties. The developed species-diagnostic SNP

  10. Cuba: exploring the history of admixture and the genetic basis of pigmentation using autosomal and uniparental markers.

    Science.gov (United States)

    Marcheco-Teruel, Beatriz; Parra, Esteban J; Fuentes-Smith, Evelyn; Salas, Antonio; Buttenschøn, Henriette N; Demontis, Ditte; Torres-Español, María; Marín-Padrón, Lilia C; Gómez-Cabezas, Enrique J; Alvarez-Iglesias, Vanesa; Mosquera-Miguel, Ana; Martínez-Fuentes, Antonio; Carracedo, Angel; Børglum, Anders D; Mors, Ole

    2014-07-01

    We carried out an admixture analysis of a sample comprising 1,019 individuals from all the provinces of Cuba. We used a panel of 128 autosomal Ancestry Informative Markers (AIMs) to estimate the admixture proportions. We also characterized a number of haplogroup diagnostic markers in the mtDNA and Y-chromosome in order to evaluate admixture using uniparental markers. Finally, we analyzed the association of 16 single nucleotide polymorphisms (SNPs) with quantitative estimates of skin pigmentation. In the total sample, the average European, African and Native American contributions as estimated from autosomal AIMs were 72%, 20% and 8%, respectively. The Eastern provinces of Cuba showed relatively higher African and Native American contributions than the Western provinces. In particular, the highest proportion of African ancestry was observed in the provinces of Guantánamo (40%) and Santiago de Cuba (39%), and the highest proportion of Native American ancestry in Granma (15%), Holguín (12%) and Las Tunas (12%). We found evidence of substantial population stratification in the current Cuban population, emphasizing the need to control for the effects of population stratification in association studies including individuals from Cuba. The results of the analyses of uniparental markers were concordant with those observed in the autosomes. These geographic patterns in admixture proportions are fully consistent with historical and archaeological information. Additionally, we identified a sex-biased pattern in the process of gene flow, with a substantially higher European contribution from the paternal side, and higher Native American and African contributions from the maternal side. This sex-biased contribution was particularly evident for Native American ancestry. Finally, we observed that SNPs located in the genes SLC24A5 and SLC45A2 are strongly associated with melanin levels in the sample. PMID:25058410

  11. Nuclear species-diagnostic SNP markers mined from 454 amplicon sequencing reveal admixture genomic structure of modern citrus varieties.

    Science.gov (United States)

    Curk, Franck; Ancillo, Gema; Ollitrault, Frédérique; Perrier, Xavier; Jacquemoud-Collet, Jean-Pierre; Garcia-Lor, Andres; Navarro, Luis; Ollitrault, Patrick

    2015-01-01

    Most cultivated Citrus species originated from interspecific hybridisation between four ancestral taxa (C. reticulata, C. maxima, C. medica, and C. micrantha) with limited further interspecific recombination due to vegetative propagation. This evolution resulted in admixture genomes with frequent interspecific heterozygosity. Moreover, a major part of the phenotypic diversity of edible citrus results from the initial differentiation between these taxa. Deciphering the phylogenomic structure of citrus germplasm is therefore essential for an efficient utilization of citrus biodiversity in breeding schemes. The objective of this work was to develop a set of species-diagnostic single nucleotide polymorphism (SNP) markers for the four Citrus ancestral taxa covering the nine chromosomes, and to use these markers to infer the phylogenomic structure of secondary species and modern cultivars. Species-diagnostic SNPs were mined from 454 amplicon sequencing of 57 gene fragments from 26 genotypes of the four basic taxa. Of the 1,053 SNPs mined from 28,507 kb sequence, 273 were found to be highly diagnostic for a single basic taxon. Species-diagnostic SNP markers (105) were used to analyse the admixture structure of varieties and rootstocks. This revealed C. maxima introgressions in most of the old and in all recent selections of mandarins, and suggested that C. reticulata × C. maxima reticulation and introgression processes were important in edible mandarin domestication. The large range of phylogenomic constitutions between C. reticulata and C. maxima revealed in mandarins, tangelos, tangors, sweet oranges, sour oranges, grapefruits, and orangelos is favourable for genetic association studies based on phylogenomic structures of the germplasm. Inferred admixture structures were in agreement with previous hypotheses regarding the origin of several secondary species and also revealed the probable origin of several acid citrus varieties. The developed species-diagnostic SNP

  12. Pulmonary ventilation/perfusion scan

    Science.gov (United States)

    V/Q scan; Ventilation/perfusion scan; Lung ventilation/perfusion scan ... A pulmonary ventilation/perfusion scan is actually two tests. They may be done separately or together. During the perfusion scan, a health ...

  13. Effect of additives with common cation on the radiolysis of ammonium, sodium and potassium nitrates in admixtures

    International Nuclear Information System (INIS)

    Gamma radiolysis of admixtures of NH4NO3, NaNO3 and KNO3 with additive salts having common cation has been studied over a wide range of nitrate salt concentration and absorbed dose. Radiolytic decomposition of nitrate salt depends on the concentration of nitrate in the admixture as well as the total absorbed dose. G(NO2-) values calculated on the basis of electron fraction of the nitrate salt decrease with the increase in mol% of the nitrate salt in somewhat exponential manner. In (NaNO3 + Na2SO4) and (KNO3 + KX, where X = Cl, Br, I) systems decomposition was found to increase linearly with the absorbed dose in the composition range of 20-100 mol%. The additives seem to exhibit sensitization effect causing extra decomposition by the energy transfer process in solid state. The efficiency of energy transfer depends on the nature of added salt, concentration of the nitrate in admixture and absorbed dose. (author)

  14. In vivo efficacy and toxicity evaluation of polycaprolactone nanoparticles and aluminum based admixture formulation as vaccine delivery system.

    Science.gov (United States)

    Bansal, Vivek; Kumar, Manoj; Bhardwaj, Arun; Brahmne, H G; Singh, Harpal

    2015-10-13

    Delivery of antigen through admixture formulation containing poly caprolactone (PCL) and aluminum phosphate was studied as a promising strategy to generate antigen specific immune response. The present study demonstrates the synergistic effect of admixture formulation of PCL with reduced aluminum (PCL-Al 0.2 mg-TT and PCL-PEG-Al 0.2 mg-TT) as a potential adjuvant system using tetanus toxoid (TT) as a model antigen. On evaluation of the magnitude of efficacy for the proposed formulation by ELISA as well as challenge method, persistent and strong antibody response was obtained throughout the 180 day study period on storage at 5 ± 3 °C. In comparison to the aluminum phosphate based conventional tetanus vaccine, higher levels of IFN-γ and IL-4 were obtained with PCL-Al 0.2 mg-TT and PCL-PEG-Al 0.2 mg-TT, indicating the presence of cell mediated as well as humoral immune responses. Histopathology and serum biochemistry profile in mice further indicated the suitability of the proposed formulation. Percent adsorption/encapsulation of the antigen also increased to nearly 95% in the admixture formulation compared to 55% adsorption in the conventional tetanus vaccine. The present study established a useful baseline for designing biocompatible and effective delivery system for toxoid vaccines through judicious use of PCL based biodegradable nanoparticles in combination with aluminum phosphate. PMID:26343498

  15. Scan path entropy and arrow plots: capturing scanning behavior of multiple observers.

    Science.gov (United States)

    Hooge, Ignace; Camps, Guido

    2013-01-01

    Designers of visual communication material want their material to attract and retain attention. In marketing research, heat maps, dwell time, and time to AOI first hit are often used as evaluation parameters. Here we present two additional measures (1) "scan path entropy" to quantify gaze guidance and (2) the "arrow plot" to visualize the average scan path. Both are based on string representations of scan paths. The latter also incorporates transition matrices and time required for 50% of the observers to first hit AOIs (T50). The new measures were tested in an eye tracking study (48 observers, 39 advertisements). Scan path entropy is a sensible measure for gaze guidance and the new visualization method reveals aspects of the average scan path and gives a better indication in what order global scanning takes place. PMID:24399993

  16. Scan path entropy and Arrow plots: Capturing scanning behavior of multiple observers

    Directory of Open Access Journals (Sweden)

    Ignace T C Hooge

    2013-12-01

    Full Text Available Designers of visual communication material want their material to attract and retain attention. In marketing research, heat maps, dwell time, and time to AOI first hit are often used as evaluation parameters. Here we present two additional measures 1 scan path entropy to quantify gaze guidance and 2 the arrow plot to visualize the average scan path. Both are based on string representations of scan paths. The latter also incorporates transition matrices and time required for 50% of the observers to first hit AOIs (T50. The new measures were tested in an eye tracking study (48 observers, 39 advertisements. Scan path entropy is a sensible measure for gaze guidance and the new visualization method reveals aspects of the average scan path and gives a better indication in what order global scanning takes place.

  17. Testing models of speciation from genome sequences: divergence and asymmetric admixture in Island South-East Asian Sus species during the Plio-Pleistocene climatic fluctuations.

    Science.gov (United States)

    Frantz, Laurent A F; Madsen, Ole; Megens, Hendrik-Jan; Groenen, Martien A M; Lohse, Konrad

    2014-11-01

    In many temperate regions, ice ages promoted range contractions into refugia resulting in divergence (and potentially speciation), while warmer periods led to range expansions and hybridization. However, the impact these climatic oscillations had in many parts of the tropics remains elusive. Here, we investigate this issue using genome sequences of three pig (Sus) species, two of which are found on islands of the Sunda-shelf shallow seas in Island South-East Asia (ISEA). A previous study revealed signatures of interspecific admixture between these Sus species (Genome biology, 14, 2013, R107). However, the timing, directionality and extent of this admixture remain unknown. Here, we use a likelihood-based model comparison to more finely resolve this admixture history and test whether it was mediated by humans or occurred naturally. Our analyses suggest that interspecific admixture between Sunda-shelf species was most likely asymmetric and occurred long before the arrival of humans in the region. More precisely, we show that these species diverged during the late Pliocene but around 23% of their genomes have been affected by admixture during the later Pleistocene climatic transition. In addition, we show that our method provides a significant improvement over D-statistics which are uninformative about the direction of admixture. PMID:25294645

  18. Utilization of water-reducing admixtures in cemented paste backfill of sulphide-rich mill tailings.

    Science.gov (United States)

    Ercikdi, Bayram; Cihangir, Ferdi; Kesimal, Ayhan; Deveci, Haci; Alp, Ibrahim

    2010-07-15

    This study presents the effect of three different water-reducing admixtures (WRAs) on the rheological and mechanical properties of cemented paste backfill (CPB) samples. A 28-day strength of > or = 0.7 MPa and the maintenance of the stability (i.e. > or = 0.7 MPa) over 360 days of curing were desired as the design criteria. Ordinary Portland cement (OPC) and Portland composite cement (PCC) were used as binders at 5 wt.% dose. WRAs were initially tested to determine the dosage of a WRA for a required consistency of 7'' for CPB mixtures. A total of 192 CPB samples were then prepared using WRAs. The utilization of WRAs enhanced the flow characteristics of the CPB mixture and allowed to achieve the same consistency at a lower water-to-cement ratio. For OPC, the addition of WRAs appeared to improve the both short- and long-term performance of CPB samples. However, only polycarboxylate-based superplasticiser produced the desired 28-day strength of > or = 0.7 MPa when PCC was used as the binder. These findings suggest that WRAs can be suitably exploited for CPB of sulphide-rich tailings to improve the strength and stability in short and long terms allowing to reduce binder costs in a CPB plant. PMID:20382473

  19. Genetics, surnames, grandparents' nationalities, and ethnic admixture in Southern Brazil: Do the patterns of variation coincide?

    Directory of Open Access Journals (Sweden)

    Dornelles C.L.

    1999-01-01

    Full Text Available A total of 2,708 individuals from the European-derived population of Rio Grande do Sul, divided into seven mesoregions, and of 226 individuals of similar origin from Santa Catarina were studied. Seventeen protein genetic systems, as well as grandparents' nationalities, individuals' surnames, and interethnic admixture were investigated. The alleles which presented the highest and lowest differences were GLO1*2 (16% and PGD*A (2%, respectively, but in general no significant genetic differences were found among mesoregions. The values observed were generally those expected for individuals of European descent, with the largest difference being a lower prevalence (34-39% of P*1. Significant heterogeneity among mesoregions was observed for the other variables considered, and was consistent with historical records. The Amerindian contribution to the gene pool of European-derived subjects in Rio Grande do Sul was estimated to be as high as 11%. Based on the four data sets, the most general finding was a tendency for a northeast-southwest separation of the populations studied. Seven significant phenotype associations between systems were observed at the 5% level (three at the 0.1% level. Of the latter, the two most interesting (since they were also observed in other studies were MNSs/Duffy and Rh/ACP.

  20. PERFORMANCE OF MICROWAVE INCINARATED RICE HUSK ASH AND USED ENGINE OIL AS A GREEN CONCRETE ADMIXTURES

    Directory of Open Access Journals (Sweden)

    B. SALMIA

    2015-12-01

    Full Text Available The utilization of waste materials in the construction industry is a novel approach let alone if these materials can further enhance the durability of the structures. Amongst the waste materials identified to be incorporated in this study is Rice Husk Ash (RHA and Used Engine Oil (UEO. Productions of these waste materials are colossal with annual volume of 1.35 billion gallon and 40 million tons of used engine oil and rice husk respectively. The main aim of this research is to establish the effects of these two waste materials (as ingredients in concrete. The rice husk was burn using microwave incinerator to produce better quality of Microwave Incinerated Rice Husk Ash (MIRHA. The pozzolanic reactivity of MIRHA helped to enhance concrete durability. The used engine oil acted as an admixture that improved the fresh state of the concrete. Workability, entrained air and compressive strength tests were conducted and the result showed that the concrete illustrated better performance compared to control sample in terms of workability, air contain and compressive strength.

  1. Efficiency of the coherent biexciton admixture mechanism for multiple exciton generation in InAs nanocrystals

    International Nuclear Information System (INIS)

    We study the coherent mixing between two-particle (single exciton) and four-particle (biexciton) states of a semiconductor nanocrystal resulting from the Coulomb coupling between states with different numbers of electron-hole pairs. Using a simple model of the nanocrystal wave functions and an envelope function approach, we estimate the efficiency of the multiple exciton generation (MEG) process resulting from such coherent admixture mechanism, including all the relevant states in a very broad energy interval. We show that in a typical ensemble of nanocrystals with an average radius of 3nm, the onset of the MEG process appears about 1 eV above the lower edge of the biexciton density of states. This is due to the angular momentum conservation that imposes selection rules and limits the available MEG pathways, thus taking over the role of momentum conservation that hinders this process in bulk. The efficiency of the MEG process reaches 50% for photon energies around 5 eV. The MEG onset shifts to lower energies and therefore the efficiency increases in a certain energy range as the radius grows. The energy dependence of the MEG efficiency differs considerably between ensembles with small and large inhomogeneity of nanocrystal sizes. (paper)

  2. Genetic structure of marine Borrelia garinii and population admixture with the terrestrial cycle of Lyme borreliosis.

    Science.gov (United States)

    Gómez-Díaz, Elena; Boulinier, Thierry; Sertour, Natacha; Cornet, Muriel; Ferquel, Elisabeth; McCoy, Karen D

    2011-09-01

    Despite the importance of population structure for the epidemiology of pathogenic bacteria, the spatial and ecological heterogeneity of these populations is often poorly characterized. Here, we investigated the genetic diversity and population structure of the Lyme borreliosis (LB) spirochaete Borrelia garinii in its marine cycle involving colonial seabirds and different host races of the seabird tick Ixodes uriae. Multilocus sequence analyses (MLSA) on eight chromosomal and two plasmid loci (ospA and ospC) indicate that B. garinii circulating in the marine system is highly diverse. Microevolution in marine B. garinii seems to be mainly clonal, but recombination and selection do occur. Sequence types were not evenly distributed among geographic regions, with substantial population subdivision between Atlantic and Pacific Ocean basins. However, no geographic structuring was evident within regions. Results of selection analyses and phylogenetic discordance between chromosomal and plasmid loci indicate adaptive evolution is likely occurring in this system, but no pattern of host or vector-associated divergence was found. Recombination analyses showed evidence for population admixture between terrestrial and marine strains, suggesting that LB spirochaetes are exchanged between these enzootic cycles. Importantly, our results highlight the need to explicitly consider the marine system for a complete understanding of the evolutionary ecology and global epidemiology of Lyme borreliosis. PMID:21651685

  3. Use of admixtures in organic-contaminated cement-clay pastes.

    Science.gov (United States)

    Gallo Stampino, Paola; Zampori, Luca; Dotelli, Giovanni; Meloni, Paola; Sora, Isabella Natali; Pelosato, Renato

    2009-01-30

    In this work microstructure, porosity and hydration degree of cement-based solidified/stabilized wasteforms were studied before assessing their leaching behaviour. 2-Chloroaniline was chosen as a model liquid organic pollutant and included into cement pastes, which were also modified with different admixtures for concrete: a superplasticizer based on acrylic-modified polymer, a synthetic rubber latex and a waterproofing agent. An organoclay, modified with an ammonium quaternary salt (benzyl-dimethyl-tallowammonium, BDMTA), was added to the pastes as pre-sorbent agent of the organic matter. All the samples were dried up to constant weight in order to stop the hydration process at different times during the first 28 days of curing, typically, after 1 day (1d), 7 days (7d) and 28 days. Then, the microstructure of the hardened cement-clay pastes was investigated by powder X-ray diffraction (XRD). The hydration degree and porosity were studied by thermal analysis (TG/DTA) and mercury intrusion porosimetry (MIP), respectively. For samples cured for 28 days a short-term leach test set by Italian regulation for industrial waste recycling (D.M. 5 February 1998) was performed. The best results showed a 5% release of the total initial amount of organic pollutant. PMID:18514398

  4. Search for an admixture of sterile neutrino in the electron spectrum from tritium $\\beta$-decay

    CERN Document Server

    Abdurashitov, D; Likhovid, N; Lokhov, A; Tkachev, I; Yants, V

    2014-01-01

    We propose an experiment intended for search for an admixture of sterile neutrino with mass m$_s$ in the range of 1-8 keV that may be detected as specific distortion of the electron energy spectrum during tritium decay. The distortion is spread over large part of the spectrum so to reveal it one can use a detector with relatively poor (near 10-15%) energy resolution. A classic proportional counter is a simple natural choice for a tritium $\\beta$-decay detector. The method we are proposing is original in two respects. First, the counter is produced as a whole from fully-fused quartz tube allowing to measure current pulse directly from anode while providing high stability for a long time. Second, a modern digital acquisition technique can be used in measurements at ultrahigh count rate - up to 10$^6$ Hz. As a result an energy spectrum of tritium electrons containing up to 10$^{12}$ counts may be collected in a month of live time measurements. Due to high statistics an upper limit down to 10$^{-3}$..10$^{-5}$ ca...

  5. USE OF CERTAIN ADMIXTURES IN THE CONSTRUCTION OF PAVEMENT ON EXPANSIVE CLAYEY SUBGRADES

    Directory of Open Access Journals (Sweden)

    D.NEERAJA,

    2010-11-01

    Full Text Available Due to rapid industrialization throughout the world, the production of huge quantity of produced waste materials creates not only the environmental problem but also the depositional hazards. Many procedures have been developed to improve the mechanical properties of soil by incorporating a wide range of stabilizing agents, additives and conditioners. In this paper, an attempt has been made to utilize industrial wastes like Rice Husk Ash (RHA, Fly Ash (FA and Ground Granulated Blast furnace Slag (GGBS as stabilizing agents. In addition to these, Lime was also added as stabilizing agent. The effect of Lime, RHA, FA and GGBS on certain properties of soil such as Optimum moisture content (OMC, Maximum Dry Density(MDD, Unconfined Compressive Strength (UCS and California Bearing Ratio (CBR has been studied. It has been established by experiments conducted on the samples that there is a maximum change in the properties with addition of lime up to 5%, RHA and GGBS up to 15% per cent and FA up to 20%. Of all the admixtures, Lime shows considerable increase in strength characteristics at an optimum lime content of 5% which gave maximum.

  6. Genetics, surnames, grandparents' nationalities, and ethnic admixture in Southern Brazil: Do the patterns of variation coincide?

    Directory of Open Access Journals (Sweden)

    C.L. Dornelles

    1999-06-01

    Full Text Available A total of 2,708 individuals from the European-derived population of Rio Grande do Sul, divided into seven mesoregions, and of 226 individuals of similar origin from Santa Catarina were studied. Seventeen protein genetic systems, as well as grandparents' nationalities, individuals' surnames, and interethnic admixture were investigated. The alleles which presented the highest and lowest differences were GLO1*2 (16% and PGD*A (2%, respectively, but in general no significant genetic differences were found among mesoregions. The values observed were generally those expected for individuals of European descent, with the largest difference being a lower prevalence (34-39% of P*1. Significant heterogeneity among mesoregions was observed for the other variables considered, and was consistent with historical records. The Amerindian contribution to the gene pool of European-derived subjects in Rio Grande do Sul was estimated to be as high as 11%. Based on the four data sets, the most general finding was a tendency for a northeast-southwest separation of the populations studied. Seven significant phenotype associations between systems were observed at the 5% level (three at the 0.1% level. Of the latter, the two most interesting (since they were also observed in other studies were MNSs/Duffy and Rh/ACP.

  7. Mechanical performance and ultrasonic properties of cemented gangue backfill with admixture of fly ash.

    Science.gov (United States)

    Wu, Di; Zhang, Yongliang; Liu, Yucheng

    2016-01-01

    Cemented gangue backfill (CGB) is prepared by mixing cement, coal gangue and water. Fly ash from the combustion of coal is commonly utilized as admixture to improve the mechanical performance and fluidity of CGB, as well as to reduce cost of preparing CGB. Uniaxial compressive strength (UCS) is one of the most commonly used indicators for evaluating the mechanical performance of CGB. Ultrasonic testing, which is a non-destructive measurement, can also be applied to determine the mechanical properties of cementitious materials such as CGB. So this paper investigates the UCS and ultrasonic pulse velocity (UPV) of CGB prepared at different fly ash dosage (19, 20 and 21 wt.%) and solid content (76.5, 77.5 and 78.5 wt.%), versus curing periods of 3-28 days. The UCS and UPV values of CGB increase with increasing fly ash dosage and solid content. In order to find out the correlation between the UCS and UPV values of CGB, different types (linear, logarithmic, exponential and power) of curve fitting are conducted on the CGB samples made at different solid content. An exponential relationship with the correlation coefficient of 0.959 appears to exist between the UCS and UPV for CGB samples. This obtained exponential relationship is validated to be available by performing the t- and F- tests. The results acquired by this paper are capable of providing guidance for utilizing UPV test to estimate the strength of underground CGB structures. PMID:26320702

  8. Study Of Characteristics Strength of Concrete with Admixtures by Flexural and Disc Bending Test

    Directory of Open Access Journals (Sweden)

    Anant Kumar

    2014-08-01

    Full Text Available Concrete is widely used in structural engineering with its high compressive strength, low cost and abandoned raw material, but common concrete has some deficiency, such as shrinkage and cracking, low tensile strength and flexural strength, high brittleness, that restrict its applications. To overcome these deficiencies’ additional materials are added to improve the performance of the concrete. Super plasticizer is a chemical added to conventional concrete mix that makes the concrete more workable and it can be placed easily. The aim of this project work to study the characteristics strengths of concrete such as compressive strength, flexural strength, split tensile strength, diametric strength and tensile strength by disc bending test. For the experimental work normal concrete M 40 has to be prepared and characteristics strength such as compressive strength, tensile strength, and flexural strength have to be achieved. This strength has to be performed after 7 days and 28 days curing. After that in addition of super plasticizer the study of the strength have to be performed with various % of plasticizer such as 0.60% to 1.2 % by the weight of cement and study of strength of concrete have to be performed at 7 days and 28 days. A relative comparison of the strength of the concrete with addition of admixtures with normal concrete can be study.

  9. Performance of rice husk ash produced using a new technology as a mineral admixture in concrete

    International Nuclear Information System (INIS)

    This article investigates the use of a new technique for the controlled combustion of Egyptian rice husk to mitigate the environmental concerns associated with its uncontrolled burning and provide a supplementary cementing material for the local construction industry. The reactor used provides efficient combustion of rice husk in a short residency time via the suspension of processed particles by jets of a process air stream that is forced though stationary angled blades at high velocity. Investigations on the rice husk ash (RHA) thus produced included oxide analysis, X-ray diffraction, carbon content, grindability, water demand, pozzolanic activity index, surface area, and particle size distribution measurements. In addition, concrete mixtures incorporating various proportions of silica fume (SF) and Egyptian RHA (EG-RHA) produced at different combustion temperatures were made and compared. The workability, superplasticizer and air-entraining admixture requirements, and compressive strength at various ages of these concrete mixtures were evaluated, and their resistance to rapid chloride penetrability and deicing salt surface scaling were examined. Test results indicate that contrary to RHA produced using existing technology, the superplasticizer and air-entraining agent requirements did not increase drastically when the RHA developed in this study was used. Compressive strengths achieved by concrete mixtures incorporating the new RHA exceeded those of concretes containing similar proportions of SF. The resistance to surface scaling of RHA concrete was better than that of concrete containing similar proportions of SF. While the chloride penetrability was substantially decreased by RHA, it remained slightly higher than that achieved by SF concrete

  10. Rapid frequency scan EPR.

    Science.gov (United States)

    Tseitlin, Mark; Rinard, George A; Quine, Richard W; Eaton, Sandra S; Eaton, Gareth R

    2011-08-01

    In rapid frequency scan EPR with triangular scans, sufficient time must be allowed to insure that the magnetization in the x, y plane decays to baseline at the end of the scan, which typically is about 5T(2) after the spins are excited. To permit relaxation of signals excited toward the extremes of the scan the total scan time required may be much longer than 5T(2). However, with periodic, saw-tooth excitation, the slow-scan EPR spectrum can be recovered by Fourier deconvolution of data recorded with a total scan period of 5T(2), even if some spins are excited later in the scan. This scan time is similar to polyphase excitation methods. The peak power required for either polyphase excitation or rapid frequency scans is substantially smaller than for pulsed EPR. The use of an arbitrary waveform generator (AWG) and cross loop resonator facilitated implementation of the rapid frequency scan experiments reported here. The use of constant continuous low B(1), periodic excitation waveform, and constant external magnetic field is similar to polyphase excitation, but could be implemented without the AWG that is required for polyphase excitation. PMID:21664848

  11. Line-scanning, stage scanning confocal microscope

    Science.gov (United States)

    Carucci, John A.; Stevenson, Mary; Gareau, Daniel

    2016-03-01

    We created a line-scanning, stage scanning confocal microscope as part of a new procedure: video assisted micrographic surgery (VAMS). The need for rapid pathological assessment of the tissue on the surface of skin excisions very large since there are 3.5 million new skin cancers diagnosed annually in the United States. The new design presented here is a confocal microscope without any scanning optics. Instead, a line is focused in space and the sample, which is flattened, is physically translated such that the line scans across its face in a direction perpendicular to the line its self. The line is 6mm long and the stage is capable of scanning 50 mm, hence the field of view is quite large. The theoretical diffraction-limited resolution is 0.7um lateral and 3.7um axial. However, in this preliminary report, we present initial results that are a factor of 5-7 poorer in resolution. The results are encouraging because they demonstrate that the linear array detector measures sufficient signal from fluorescently labeled tissue and also demonstrate the large field of view achievable with VAMS.

  12. Radionucleotide scanning in osteomyelitis

    International Nuclear Information System (INIS)

    Radionucleotide bone scanning can be an excellent adjunct to the standard radiograph and clinical findings in the diagnosis of osteomyelitis. Bone scans have the ability to detect osteomyelitis far in advance of the standard radiograph. The sequential use of technetium and gallium has been useful in differentiating cellulitis and osteomyelitis. Serial scanning with technetium and gallium may be used to monitor the response of osteomyelitis to antibiotic therapy

  13. Mapping geomorphology: A journey from paper maps, through computer mapping to GIS and Virtual Reality

    Science.gov (United States)

    Vitek, John D.; Giardino, John R.; Fitzgerald, Jeffrey W.

    1996-07-01

    Maps are integral components of research in geomorphology and Quaternary geology. Visual presentation of the spatial and temporal distribution of a phenomenon often provides clues to the process(es) that generated the phenomenon. Compiling information on maps, interpreting spatial patterns, and using standard topographic maps were fundamental parts of the undergraduate experience. Why have such experiences been slowly disappearing from undergraduate curricula? How are geology majors taught map scale, map projections, and the pitfalls associated with the display of spatial information? Neglect in preserving the mapping tradition places the geology major at a disadvantage. The use of maps and mapping is undergoing a renaissance; use in the classroom has a bright future because of digital scanning, computer cartography, geographic information systems (GIS), and virtual reality. Pen and ink techniques should be relegated to museums. Pencil sketches can be scanned and perfect products generated every time. These techniques, however, do not eliminate the need for basic map knowledge such as scale, projections, and generalization. What assumptions about map projections have been built into the software? How are spatial data and attribute data integrated into the resultant map in a geographic information system (GIS)? Because the application of virtual reality to geomorphic processes looms on the horizon, geologists must recognize how the current spatial revolution can help with the assessment of geologic phenomena and teach students to function with the new technology.

  14. Coagulated silica - a-SiO2 admixture in cement paste

    Science.gov (United States)

    Pokorný, Jaroslav; Pavlíková, Milena; Záleská, Martina; Rovnaníková, Pavla; Pavlík, Zbyšek

    2016-07-01

    Amorphous silica (a-SiO2) in fine-grained form possesses a high pozzolanic activity which makes it a valuable component of blended binders in concrete production. The origin of a-SiO2 applied in cement-based composites is very diverse. SiO2 in amorphous form is present in various amounts in quite a few supplementary cementing materials (SCMs) being used as partial replacement of Portland cement. In this work, the applicability of a commercially produced coagulated silica powder as a partial replacement of Portland cement in cement paste mix design is investigated. Portland cement CEM I 42.5R produced according to the EU standard EN 197-1 is used as a reference binder. Coagulated silica is applied in dosages of 5 and 10 % by mass of cement. The water/binder ratio is kept constant in all the studied pastes. For the applied silica, specific surface area, density, loss on ignition, pozzolanic activity, chemical composition, and SiO2 amorphous phase content are determined. For the developed pastes on the basis of cement-silica blended binder, basic physical properties as bulk density, matrix density, and total open porosity are accessed. Pore size distribution is determined using MIP analysis. Initial and final setting times of fresh mixtures are measured by automatic Vicat apparatus. Effect of silica admixture on mechanical resistivity is evaluated using compressive strength, bending strength, and dynamic Young's modulus measurement. The obtained data gives evidence of a decreased workability of paste mixtures with silica, whereas the setting process is accelerated. On the other hand, reaction activity of silica with Portland cement minerals results in a slight decrease of porosity and improvement of mechanical resistivity of cement pastes containing a-SiO2.

  15. Turbulent Prandtl number in the A model of passive vector admixture

    Science.gov (United States)

    Jurčišinová, E.; Jurčišin, M.; Remecký, R.

    2016-03-01

    Using the field theoretic renormalization group technique in the second-order (two-loop) approximation the explicit expression for the turbulent vector Prandtl number in the framework of the general A model of passively advected vector field by the turbulent velocity field driven by the stochastic Navier-Stokes equation is found as the function of the spatial dimension d >2 . The behavior of the turbulent vector Prandtl number as the function of the spatial dimension d is investigated in detail especially for three physically important special cases, namely, for the passive advection of the magnetic field in a conductive turbulent environment in the framework of the kinematic MHD turbulence (A =1 ), for the passive admixture of a vector impurity by the Navier-Stokes turbulent flow (A =0 ), and for the model of linearized Navier-Stokes equation (A =-1 ). It is shown that the turbulent vector Prandtl number in the framework of the A =-1 model is exactly determined already in the one-loop approximation, i.e., that all higher-loop corrections vanish. At the same time, it is shown that it does not depend on spatial dimension d and is equal to 1. On the other hand, it is shown that the turbulent magnetic Prandtl number (A =1 ) and the turbulent vector Prandtl number in the model of a vector impurity (A =0 ), which are essentially different at the one-loop level of approximation, become very close to each other when the two-loop corrections are taken into account. It is shown that their relative difference is less than 5 % for all integer values of the spatial dimension d ≥3 . Obtained results demonstrate strong universality of diffusion processes of passively advected scalar and vector quantities in fully symmetric incompressible turbulent environments.

  16. Partial constriction in a glow discharge in argon with nitrogen admixture

    International Nuclear Information System (INIS)

    The constriction of the positive column of a glow discharge in argon with nitrogen admixture (0.02–1%) was studied. The discharge was maintained in a tube of 2.8 cm inner diameter and 75 cm length at intermediate pressures (several tens of Torrs), at which the discharge constriction goes by a jump and the hysteresis effect is well pronounced. It was observed that the constriction begins near one of the electrodes and then the constricted region boundary propagates toward the other electrode. The reverse transition occurs in a similar way. The transition time in Ar : N2 mixtures appears to be essentially longer (up to 1 s) than that in pure argon. By varying the power supply voltage in the course of the transition, the boundary between the diffuse and constricted forms of the discharge could be stopped at some position between the electrodes. Such a partially constricted discharge (PCD) is stable and can exist for a long time. A PCD at various locations of the boundary can be formed, different locations being realized at different discharge voltages but at the same discharge current. This corresponds to a vertical segment in the voltage–current characteristic curve. It was found that this segment lies inside the hysteresis loop and connects two branches of the conventional I–V characteristic measured without affecting the discharge during the diffuse-to-constricted or reverse transitions. Plasma parameters in the diffuse and constricted positive columns are estimated and ionization mechanisms are analyzed. The possible reasons for the low velocity of the constriction front in Ar : N2 mixtures and the mechanisms of the stabilization of the PCD are also discussed. (paper)

  17. First PET scans in Estonia

    International Nuclear Information System (INIS)

    First PET scans in Estonia were performed on 25th November 2002 in North Estonia Regional Hospital, Tallinn. Six patients with melanoma underwent scanning with FDG. This event was a result of thorough extensive preparations first started in 2000 during the European Association of Nuclear Medicine congress in Paris. During the congress first contacts were made with providers of mobile PET units. At the same time negotiations were begun with potential FDG suppliers. For the introduction of PET in Estonia mobile truckmounted scanning technology was chosen due to low level of initial investments. Of particular importance was also availability of maintenance personnel from the device providers. A significant prerequisite was potential availability of FDG from the neighbourhood - Finland and Sweden. The latter avoided the necessity for investments into local cyclotrons and local FDG production. For the first scanning experience the dedicated truckmounted PET-camera Accel, Siemens was brought by the International Hospital Group (IHG, Amersfoort, Netherlands). The device arrived by ferry from Stockholm to Tallinn harbour at 10 o'clock in the morning and left by ferry for Helsinki at 23 o'clock. The team-on-truck consisted of one technician for device operation, two drivers and two company representatives. North Estonia Regional Hospital provided three additional technicians for patient preparation and FDG injection, one nuclear medicine doctor and one specialist of biomedical engineering and medical physics. The FDG was provided by MAP Medical Technologies, Schering, Helsinki, Finland. The shipments were made by air. This was possible due to small distance between Tallinn and Helsinki of approximately 80 km due to the regular flight connections between the two cities. The FDG was shipped in two lots with a time interval of 4 hours. The patient selection was based on clinical and histopathology data. In all six patients the exam was justified for detailied staging and

  18. Combination of admixtures to improve the robustness of high-volume fly ash concrete in hot weather[ACI SP-239

    Energy Technology Data Exchange (ETDEWEB)

    Nkinamubanzi, P.C. [Natural Resources Canada, Ottawa, ON (Canada). CANMET International Centre for Sustainable Development of Cement and Concrete]|[American Concrete Inst. Farmington Hills, MI (United States); Bhattacharya, A.; Sharma, A. [Hindustan Construction Co., Mumbai (India)

    2006-07-01

    A precise admixtures system is needed when using high-volume fly ash concrete as fresh concrete occasionally undergoes rapid slump loss after mixing, which can cause problems with casting, pumping and finishing of the concrete in hot weather. This paper provided details of a study conducted to implement high-volume fly ash concrete technology in India. Different families of admixtures were investigated to determine their water reduction capacities. A set-retarding admixture was used in some of the concrete mixtures in order to determine its efficacy. An Indian Portland cement was used to create a total of 22 different concrete mixtures. Four different fly ashes were used to replace portions of the concrete. The slump of the fresh concrete mixture was monitored for 2 to 3 hours. Unit weight and temperature of the concrete was measured. Specimens were cast in steel moulds in order to determine the compressive strength and unit weight of the hardened concrete. The concretes were demoulded after 24 hours and cured in a water tank. Results of the study showed that 4 concrete mixtures showed good slump retention after 2 hours. The concretes were made using a combination of polycarboxylate-based admixtures from the naphthalene family. Concrete mixtures using admixtures made from sulfonated polymers also showed good slump resistance. Results showed that the selection of good combinations of admixtures can lead to excellent high volume fly ash concrete mixtures that are resistant to hot weather conditions. Exceptional results were achieved with concrete mixtures using a combination of polycarboxylates-based superplasticizers and sulfonated mid-range water-reducing admixtures. 7 refs., 8 tabs., 3 figs.

  19. Getting a CAT Scan

    Medline Plus

    Full Text Available ... Snowboarding, Skating Crushes What's a Booger? Getting a CAT Scan (Video) KidsHealth > For Kids > Getting a CAT Scan (Video) Print A A A Text Size en español Obtención de una tomografía computada (video) CAT stands for "computerized axial tomography." Translated, that means ...

  20. Getting a CAT Scan

    Medline Plus

    Full Text Available ... Here's Help White House Lunch Recipes Getting a CAT Scan (Video) KidsHealth > For Kids > Getting a CAT Scan (Video) Print A A A Text Size en español Obtención de una tomografía computada (video) CAT stands for "computerized axial tomography." Translated, that means ...

  1. Abdominal CT scan

    Science.gov (United States)

    ... than regular x-rays. Many x-rays or CT scans over time may increase your risk for cancer. However, the risk from any one scan is small. Talk to your doctor about this risk and the benefit of the test for getting a correct diagnosis ...

  2. Knee CT scan

    Science.gov (United States)

    Risks of CT scans include: Exposure to radiation Allergy to contrast dye CT scans give off more radiation than ... injected contrast dye. The most common type of contrast contains ... you have this an iodine allergy. If you need to have this kind of ...

  3. Knee CT scan

    Science.gov (United States)

    A computed tomography (CT) scan of the knee is a test that uses x-rays to take detailed images of the knee. ... A CT scan can quickly create more detailed pictures of the knee than standard x-rays. The test may be ...

  4. Frequency scanning microstrip antennas

    DEFF Research Database (Denmark)

    Danielsen, Magnus; Jørgensen, Rolf

    1979-01-01

    The principles of using radiating microstrip resonators as elements in a frequency scanning antenna array are described. The resonators are cascade-coupled. This gives a scan of the main lobe due to the phase-shift in the resonator in addition to that created by the transmission line phase...

  5. Environmental Scanning Report.

    Science.gov (United States)

    Truckee Meadows Community Coll., Sparks, NV.

    This report describes Truckee Meadows Community College's (Nevada) environmental scanning process and results. The college decided that environmental scanning and forecasting techniques should be used to plan for both short-term and long-term external factors that impact programs, enrollment, and budgets. Strategic goals include: (1) keeping pace…

  6. Getting a CAT Scan

    Medline Plus

    Full Text Available ... Dictionary of Medical Words En Español What Other Kids Are Reading Movie: Digestive System Winter Sports: Sledding, ... Booger? Getting a CAT Scan (Video) KidsHealth > For Kids > Getting a CAT Scan (Video) Print A A ...

  7. Getting a CAT Scan

    Medline Plus

    Full Text Available ... Skiing, Snowboarding, Skating Crushes What's a Booger? Getting a CAT Scan (Video) KidsHealth > For Kids > Getting a CAT Scan (Video) Print A A A Text Size en español Obtención de ...

  8. Getting a CAT Scan

    Medline Plus

    Full Text Available ... Crushes What's a Booger? Getting a CAT Scan (Video) KidsHealth > For Kids > Getting a CAT Scan (Video) Print A A A Text Size en español Obtención de una tomografía computada (video) CAT stands for "computerized axial tomography." Translated, that ...

  9. Influence of shrinkage-reducing admixture on drying shrinkage and mechanical properties of high-performance concrete

    Institute of Scientific and Technical Information of China (English)

    Nguyen Quangphu; Jiang Linhua; Liu Jiaping; Tian Qian; Do Tienquan

    2008-01-01

    High-performance concrete (HPC) has specific performance advantages over conventional concrete in strength and durability. HPC mixtures are usually produced with water/binder mass ratios (mw/mB) in the range of 0.2-0.4, so volume changes of concrete as a result of drying, chemical reactions, and temperature change cannot be avoided. For these reasons, shrinkage and cracking are frequent phenomena. It is necessary to add some types of admixture for reduction of shrinkage and cracking of HPC. This study used a shrinkage-reducing admixture (SRA) for that purpose. Concrete was prepared with two different mw/mB(0.22 and 0.40) and four different mass fractions of SRA to binder (w(SRA) = 0%, 1%, 2%, and 4%). The mineral admixtures used for concrete mixes were: 25% fly ash (FA) and 25% slag by mass of binder for the mixture with mw/mB=0.40, and 15% silica fume (SF) and 25% FA for the mixture with mw/ma=0.22. Tests were conducted on 24 prismatic specimens, and shrinkage strains were measured through 120 days of drying. Compressive strength, splitting strength, and static modulus of elasticity were also determined. The results show that the SRA effectively reduces some mechanical properties of HPC. The reductions in compressive strength, splitting tensile strength, and elastic modulus of the concrete were 7%-24%, 9%-19%, and 5%-12%, respectively, after 90 days, compared to concrete mixtures without SRA. SRA can also help reduce drying shrinkage of concrete. The shrinkage strains of HPC with SRA were only as high as 41% of the average free shrinkage of concrete without SRA after 120 days of drying.

  10. Influence of shrinkage-reducing admixture on drying shrinkage and mechanical properties of high-performance concrete

    Directory of Open Access Journals (Sweden)

    Nguyen Quangphu

    2008-12-01

    Full Text Available Abstract: High-performance concrete (HPC has specific performance advantages over conventional concrete in strength and durability. HPC mixtures are usually produced with water/binder mass ratios (mW/mB in the range of 0.2-0.4, so volume changes of concrete as a result of drying, chemical reactions, and temperature change cannot be avoided. For these reasons, shrinkage and cracking are frequent phenomena. It is necessary to add some types of admixture for reduction of shrinkage and cracking of HPC. This study used a shrinkage-reducing admixture (SRA for that purpose. Concrete was prepared with two different mW/mB (0.22 and 0.40 and four different mass fractions of SRA to binder (w(SRA = 0%, 1%, 2%, and 4%. The mineral admixtures used for concrete mixes were: 25% fly ash (FA and 25% slag by mass of binder for the mixture with mW/mB = 0.40, and 15% silica fume (SF and 25% FA for the mixture with mW/mB = 0.22. Tests were conducted on 24 prismatic specimens, and shrinkage strains were measured through 120 days of drying. Compressive strength, splitting strength, and static modulus of elasticity were also determined. The results show that the SRA effectively reduces some mechanical properties of HPC. The reductions in compressive strength, splitting tensile strength, and elastic modulus of the concrete were 7%-24%, 9%-19%, and 5%-12%, respectively, after 90 days, compared to concrete mixtures without SRA. SRA can also help reduce drying shrinkage of concrete. The shrinkage strains of HPC with SRA were only as high as 41% of the average free shrinkage of concrete without SRA after 120 days of drying.

  11. Influence of Air Temperature on the Performance of Different Water-Reducing Admixtures with Respect to the Properties of Fresh and Hardened Mortar

    Directory of Open Access Journals (Sweden)

    Wilson Ricardo Leal Silva

    2010-01-01

    Full Text Available The performance of water-reducing admixtures used in concrete is affected by the weather conditions to which the concrete mixture is exposed. The most used WRAs are lignosulfonate, naphthalene, and polycarboxylate. However, they react differently to weather conditions, especially to air temperature. Therefore, it can be useful to evaluate how temperature affects admixture performance. In this study, the performance of three admixtures (naphthalene, lignosulfonate, and polycarboxylate was evaluated at 15, 25, and 35°C by means of the flow table test, mixture air content, and compressive strength. Moreover, mixture temperature was monitored and time-temperature curves were plotted in order to assess whether the admixtures affected cement hydration reactions at different temperatures. The final results indicate that an increase in temperature leads to an increase in saturation dosage; lignosulfonate had the most pronounced retarding effect, followed by polycarboxylate, and finally, naphthalene, and considering the weather conditions in the area where the study was carried, the final finding would be that the naphthalene-based admixture had the best performance.

  12. Graphene Conductance Uniformity Mapping

    DEFF Research Database (Denmark)

    Buron, Jonas Christian Due; Petersen, Dirch Hjorth; Bøggild, Peter;

    2012-01-01

    We demonstrate a combination of micro four-point probe (M4PP) and non-contact terahertz time-domain spectroscopy (THz-TDS) measurements for centimeter scale quantitative mapping of the sheet conductance of large area chemical vapor deposited graphene films. Dual configuration M4PP measurements......, demonstrated on graphene for the first time, provide valuable statistical insight into the influence of microscale defects on the conductance, while THz-TDS has potential as a fast, non-contact metrology method for mapping of the spatially averaged nanoscopic conductance on wafer-scale graphene with scan times......, dominating the microscale conductance of the investigated graphene film....

  13. Development and Deployment of a Compact Eye-Safe Scanning Differential absorption Lidar (DIAL) for Spatial Mapping of Carbon Dioxide for Monitoring/Verification/Accounting at Geologic Sequestration Sites

    Energy Technology Data Exchange (ETDEWEB)

    Repasky, Kevin

    2014-03-31

    A scanning differential absorption lidar (DIAL) instrument for monitoring carbon dioxide has been developed. The laser transmitter uses two tunable discrete mode laser diodes (DMLD) operating in the continuous wave (cw) mode with one locked to the online absorption wavelength and the other operating at the offline wavelength. Two in-line fiber optic switches are used to switch between online and offline operation. After the fiber optic switch, an acousto- optic modulator (AOM) is used to generate a pulse train used to injection seed an erbium doped fiber amplifier (EDFA) to produce eye-safe laser pulses with maximum pulse energies of 66 {micro}J, a pulse repetition frequency of 15 kHz, and an operating wavelength of 1.571 {micro}m. The DIAL receiver uses a 28 cm diameter Schmidt-Cassegrain telescope to collect that backscattered light, which is then monitored using a photo-multiplier tube (PMT) module operating in the photon counting mode. The DIAL instrument has been operated from a laboratory environment on the campus of Montana State University, at the Zero Emission Research Technology (ZERT) field site located in the agricultural research area on the western end of the Montana State University campus, and at the Big Sky Carbon Sequestration Partnership site located in north-central Montana. DIAL data has been collected and profiles have been validated using a co-located Licor LI-820 Gas Analyzer point sensor.

  14. In vivowide-field multispectral scanning laser ophthalmoscopy-optical coherence tomography mouse retinal imager: longitudinal imaging of ganglion cells, microglia, and Müller glia, and mapping of the mouse retinal and choroidal vasculature

    Science.gov (United States)

    Zhang, Pengfei; Zam, Azhar; Jian, Yifan; Wang, Xinlei; Li, Yuanpei; Lam, Kit S.; Burns, Marie E.; Sarunic, Marinko V.; Pugh, Edward N., Jr.; Zawadzki, Robert J.

    2015-12-01

    Scanning laser ophthalmoscopy (SLO) and optical coherence tomography (OCT) provide complementary views of the retina, with the former collecting fluorescence data with good lateral but relatively low-axial resolution, and the latter collecting label-free backscattering data with comparable lateral but much higher axial resolution. To take maximal advantage of the information of both modalities in mouse retinal imaging, we have constructed a compact, four-channel, wide-field (˜50 deg) system that simultaneously acquires and automatically coregisters three channels of confocal SLO and Fourier domain OCT data. The scanner control system allows "zoomed" imaging of a region of interest identified in a wide-field image, providing efficient digital sampling and localization of cellular resolution features in longitudinal imaging of individual mice. The SLO is equipped with a "flip-in" spectrometer that enables spectral "fingerprinting" of fluorochromes. Segmentation of retina layers and en face display facilitate spatial comparison of OCT data with SLO fluorescence patterns. We demonstrate that the system can be used to image an individual retinal ganglion cell over many months, to simultaneously image microglia and Müller glia expressing different fluorochromes, to characterize the distinctive spatial distributions and clearance times of circulating fluorochromes with different molecular sizes, and to produce unequivocal images of the heretofore uncharacterized mouse choroidal vasculature.

  15. Low-frequency resonances of the refractive index in weakly ionized plasma with an admixture of dust

    International Nuclear Information System (INIS)

    The propagation of low-frequency electromagnetic waves along the magnetic field in weakly ionized plasma with an admixture of dust is studied in the framework of the Hall magnetohydrodynamics. Explicit expressions for the coefficients of magnetic field diffusion in plasma are derived. The resonance of the refractive index is found to occur for either right- or left-hand polarized waves. A quantitative criterion is obtained that allows one to determine the polarization of waves that experience resonance at given plasma parameters. The physical mechanism of the resonance is discussed, and the obtained results are compared with the available literature data

  16. Structural Investigations of Portland Cement Components, Hydration, and Effects of Admixtures by Solid-State NMR Spectroscopy

    DEFF Research Database (Denmark)

    Skibsted, Jørgen Bengaard; Andersen, Morten D.; Jakobsen, Hans Jørgen

    2006-01-01

    Solid-state, magic-angle spinning (MAS) NMR spectroscopy represents a valuable tool for structural investigations on the nanoscale of the most important phases in anhydrous and hydrated Portland cements and of various admixtures. This is primarily due to the fact that the method reflects the first...... have been investigated in detail by 29Si and 27Al MAS NMR where the combination of the results for these spin-nuclei provides important information on the degree of Al-incorporation in the C-S-H structure and of the average chain lengths of tetrahedral SiO4 and AlO4 units. This presentation will...

  17. Influence of shrinkage-reducing admixture on drying shrinkage and mechanical properties of high-performance concrete

    OpenAIRE

    Nguyen Quangphu; Jiang Linhua; Liu Jiaping; Tian Qian; Do Tienquan

    2008-01-01

    Abstract: High-performance concrete (HPC) has specific performance advantages over conventional concrete in strength and durability. HPC mixtures are usually produced with water/binder mass ratios (mW/mB) in the range of 0.2-0.4, so volume changes of concrete as a result of drying, chemical reactions, and temperature change cannot be avoided. For these reasons, shrinkage and cracking are frequent phenomena. It is necessary to add some types of admixture for reduction of shrinkage and crac...

  18. Laser Scanning in Forests

    Directory of Open Access Journals (Sweden)

    Håkan Olsson

    2012-09-01

    Full Text Available The introduction of Airborne Laser Scanning (ALS to forests has been revolutionary during the last decade. This development was facilitated by combining earlier ranging lidar discoveries [1–5], with experience obtained from full-waveform ranging radar [6,7] to new airborne laser scanning systems which had components such as a GNSS receiver (Global Navigation Satellite System, IMU (Inertial Measurement Unit and a scanning mechanism. Since the first commercial ALS in 1994, new ALS-based forest inventory approaches have been reported feasible for operational activities [8–12]. ALS is currently operationally applied for stand level forest inventories, for example, in Nordic countries. In Finland alone, the adoption of ALS for forest data collection has led to an annual savings of around 20 M€/year, and the work is mainly done by companies instead of governmental organizations. In spite of the long implementation times and there being a limited tradition of making changes in the forest sector, laser scanning was commercially and operationally applied after about only one decade of research. When analyzing high-ranked journal papers from ISI Web of Science, the topic of laser scanning of forests has been the driving force for the whole laser scanning research society over the last decade. Thus, the topic “laser scanning in forests” has provided a significant industrial, societal and scientific impact. [...

  19. Scanning with Iodine-125

    International Nuclear Information System (INIS)

    The use of I125 as I125-iodide for scanning of the thyroid and of thyroid carcinoma métastasés and as I125-labelled Rose Bengal for scanning of the liver has been investigated in our laboratories. In some patients, the thyroid scans and the scans of thyroid carcinoma metastases were repeated with I131. The liver scans were repeated with colloidal Au198. Cold nodules in the thyroid which could not be detected with I131 were clearly seen with I125. Anterior métastasés in the lungs could be differentiated from posterior métastasés with I125, while with I131 this was not possible. Using the same doses of radioactivity the background with I131 was much higher and could not be eliminated, as this would have reduced the counting rate over the lesions to levels which could not be detected. Some of the photoscans and mechanical scans of livers carried out with colloidal Au198 could not be interpreted. However, ''cold'' lesions were clearly seen on the scans of the same livers with I125-labelled Rose Bengal. (author)

  20. Photoelectric scanner makes detailed work function maps of metal surface

    Science.gov (United States)

    Rasor, N. S.

    1966-01-01

    Photoelectric scanning device maps the work function of a metal surface by scanning it with a light spot and measuring the resulting photocurrent. The device is capable of use over a range of surface temperatures.

  1. Breast PET scan

    Science.gov (United States)

    Breast positron emission tomography; PET - breast; PET - tumor imaging - breast ... A PET scan requires a small amount of radioactive material (tracer). This tracer is given through a vein (IV), usually ...

  2. Pediatric CT Scans

    Science.gov (United States)

    The Radiation Epidemiology Branch and collaborators have initiated a retrospective cohort study to evaluate the relationship between radiation exposure from CT scans conducted during childhood and adolescence and the subsequent development of cancer.

  3. Shoulder MRI scan

    Science.gov (United States)

    ... finding on an x-ray or bone scan Shoulder pain and fever Decreased motion of the shoulder joint ... of the shoulder joint Shoulder instability Shoulder weakness Shoulder pain and a history of cancer Shoulder pain that ...

  4. Scanning ultrafast electron microscopy

    OpenAIRE

    Yang, Ding-Shyue; Mohammed, Omar F.; Zewail, Ahmed H.

    2010-01-01

    Progress has been made in the development of four-dimensional ultrafast electron microscopy, which enables space-time imaging of structural dynamics in the condensed phase. In ultrafast electron microscopy, the electrons are accelerated, typically to 200 keV, and the microscope operates in the transmission mode. Here, we report the development of scanning ultrafast electron microscopy using a field-emission-source configuration. Scanning of pulses is made in the single-electron mode, for whic...

  5. Admixture in Latin America: geographic structure, phenotypic diversity and self-perception of ancestry based on 7,342 individuals.

    Directory of Open Access Journals (Sweden)

    Andrés Ruiz-Linares

    2014-09-01

    Full Text Available The current genetic makeup of Latin America has been shaped by a history of extensive admixture between Africans, Europeans and Native Americans, a process taking place within the context of extensive geographic and social stratification. We estimated individual ancestry proportions in a sample of 7,342 subjects ascertained in five countries (Brazil, Chile, Colombia, México and Perú. These individuals were also characterized for a range of physical appearance traits and for self-perception of ancestry. The geographic distribution of admixture proportions in this sample reveals extensive population structure, illustrating the continuing impact of demographic history on the genetic diversity of Latin America. Significant ancestry effects were detected for most phenotypes studied. However, ancestry generally explains only a modest proportion of total phenotypic variation. Genetically estimated and self-perceived ancestry correlate significantly, but certain physical attributes have a strong impact on self-perception and bias self-perception of ancestry relative to genetically estimated ancestry.

  6. Gene admixture in ethnic populations in upper part of Silk Road revealed by mtDNA polymorphism

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To evaluate the gene admixture on the current genetic landscape in Gansu Corridor (GC) in China, the upper part of the ancient Silk Road which connects the Eastern and Central Asia, we examined mitochondrial DNA (mtDNA) polymorphisms of five ethnic populations in this study. Using PCR-RFLP and sequencing, we analyzed mtDNA haplotypes in 242 unrelated samples in three ethnic populations from the GC region and two ethnic populations from the adjacent Xinjiang Uygur Autonomous Region of China. We analyzed the data in comparison with the previously reported data from Eastern, Central and Western Asia and Europe. We found that both European-specific haplogroups and Eastern Asian-specific haplogroups exist in the Gansu Corridor populations, while a modest matrilineal gene flow from Europeans to this region was revealed. The Gansu Corridor populations are genetically located between Eastern Asians and Central Asians, both of who contributed significantly to the maternal lineages of the GC populations. This study made the landscape of the gene flow and admixture along the Silk Road from Europe, through Central Asia, to the upper part of the Silk Road more complete.

  7. Influence of admixture components on CYP2C9*2 allele frequency in eight indigenous populations from Northwest Mexico.

    Science.gov (United States)

    Sosa-Macías, M; Lazalde-Ramos, B P; Galaviz-Hernández, C; Rangel-Villalobos, H; Salazar-Flores, J; Martínez-Sevilla, V M; Martínez-Fierro, M L; Dorado, P; Wong, M L; Licinio, J; LLerena, A

    2013-12-01

    We previously documented the lowest frequency of CYP2C9*2 in Mexican indigenous Tepehuanos followed by Mestizos and Mexican-Americans populations, suggesting a negative correlation between the CYP2C9*2 frequency and the degree of Asian ancestry in indigenous Americans. We determined the influence of ethnic admixture components on the CYP2C9 allele distribution in 505 Amerindian from eight indigenous populations through genotyping CYP2C9*2, *3 and *6 alleles by real-time PCR and molecular evaluation of ancestry. The frequencies for CYP2C9*2 were 0.026 in Seris and 0.057 in Mayos, being higher than in Asians (P<0.001). CYP2C9*3 was found in Tarahumaras (0.104), Mayos (0.091), Tepehuanos (0.075), Guarijíos (0.067), Huicholes (0.033) and Coras (0.037), with East Asians having lower frequencies than the former three groups (P<0.001). CYP2C9*6 was not found. The frequency of CYP2C9*2 was lower in Amerindians than in European populations, and higher than their Asian ancestors. The presence of this allele in ethnic groups in Mexico can be explained by European admixture. PMID:23358499

  8. Genetic dating indicates that the Asian–Papuan admixture through Eastern Indonesia corresponds to the Austronesian expansion

    Science.gov (United States)

    Xu, Shuhua; Pugach, Irina; Stoneking, Mark; Kayser, Manfred; Jin, Li

    2012-01-01

    Although the Austronesian expansion had a major impact on the languages of Island Southeast Asia, controversy still exists over the genetic impact of this expansion. The coexistence of both Asian and Papuan genetic ancestry in Eastern Indonesia provides a unique opportunity to address this issue. Here, we estimate recombination breakpoints in admixed genomes based on genome-wide SNP data and date the genetic admixture between populations of Asian vs. Papuan ancestry in Eastern Indonesia. Analyses of two genome-wide datasets indicate an eastward progression of the Asian admixture signal in Eastern Indonesia beginning about 4,000–3,000 y ago, which is in excellent agreement with inferences based on Austronesian languages. The average rate of spread of Asian genes in Eastern Indonesia was about 0.9 km/y. Our results indicate that the Austronesian expansion had a strong genetic as well as linguistic impact on Island Southeast Asia, and they significantly advance our understanding of the biological origins of human populations in the Asia–Pacific region. PMID:22396590

  9. Genetic dating indicates that the Asian-Papuan admixture through Eastern Indonesia corresponds to the Austronesian expansion.

    Science.gov (United States)

    Xu, Shuhua; Pugach, Irina; Stoneking, Mark; Kayser, Manfred; Jin, Li

    2012-03-20

    Although the Austronesian expansion had a major impact on the languages of Island Southeast Asia, controversy still exists over the genetic impact of this expansion. The coexistence of both Asian and Papuan genetic ancestry in Eastern Indonesia provides a unique opportunity to address this issue. Here, we estimate recombination breakpoints in admixed genomes based on genome-wide SNP data and date the genetic admixture between populations of Asian vs. Papuan ancestry in Eastern Indonesia. Analyses of two genome-wide datasets indicate an eastward progression of the Asian admixture signal in Eastern Indonesia beginning about 4,000-3,000 y ago, which is in excellent agreement with inferences based on Austronesian languages. The average rate of spread of Asian genes in Eastern Indonesia was about 0.9 km/y. Our results indicate that the Austronesian expansion had a strong genetic as well as linguistic impact on Island Southeast Asia, and they significantly advance our understanding of the biological origins of human populations in the Asia-Pacific region. PMID:22396590

  10. Admixture in Latin America: Geographic Structure, Phenotypic Diversity and Self-Perception of Ancestry Based on 7,342 Individuals

    Science.gov (United States)

    Ruiz-Linares, Andrés; Adhikari, Kaustubh; Acuña-Alonzo, Victor; Quinto-Sanchez, Mirsha; Jaramillo, Claudia; Arias, William; Fuentes, Macarena; Pizarro, María; Everardo, Paola; de Avila, Francisco; Gómez-Valdés, Jorge; León-Mimila, Paola; Hunemeier, Tábita; Ramallo, Virginia; Silva de Cerqueira, Caio C.; Burley, Mari-Wyn; Konca, Esra; de Oliveira, Marcelo Zagonel; Veronez, Mauricio Roberto; Rubio-Codina, Marta; Attanasio, Orazio; Gibbon, Sahra; Ray, Nicolas; Gallo, Carla; Poletti, Giovanni; Rosique, Javier; Schuler-Faccini, Lavinia; Salzano, Francisco M.; Bortolini, Maria-Cátira; Canizales-Quinteros, Samuel; Rothhammer, Francisco; Bedoya, Gabriel; Balding, David; Gonzalez-José, Rolando

    2014-01-01

    The current genetic makeup of Latin America has been shaped by a history of extensive admixture between Africans, Europeans and Native Americans, a process taking place within the context of extensive geographic and social stratification. We estimated individual ancestry proportions in a sample of 7,342 subjects ascertained in five countries (Brazil, Chile, Colombia, México and Perú). These individuals were also characterized for a range of physical appearance traits and for self-perception of ancestry. The geographic distribution of admixture proportions in this sample reveals extensive population structure, illustrating the continuing impact of demographic history on the genetic diversity of Latin America. Significant ancestry effects were detected for most phenotypes studied. However, ancestry generally explains only a modest proportion of total phenotypic variation. Genetically estimated and self-perceived ancestry correlate significantly, but certain physical attributes have a strong impact on self-perception and bias self-perception of ancestry relative to genetically estimated ancestry. PMID:25254375

  11. Winning the invasion roulette: escapes from fish farms increase admixture and facilitate establishment of non-native rainbow trout.

    Science.gov (United States)

    Consuegra, Sofia; Phillips, Nia; Gajardo, Gonzalo; de Leaniz, Carlos Garcia

    2011-09-01

    Aquaculture is a major source of invasive aquatic species, despite the fact that cultured organisms often have low genetic diversity and tend to be maladapted to survive in the wild. Yet, to what extent aquaculture escapees become established by means of high propagule pressure and multiple origins is not clear. We analysed the genetic diversity of 15 established populations and four farmed stocks of non-native rainbow trout in Chile, a species first introduced for recreational fishing around 1900, but which has in recent decades escaped in large numbers from fish farms and become widespread. Aquaculture propagule pressure was a good predictor of the incidence of farm escapees, which represented 16% of all free-ranging rainbow trout and were present in 80% of the study rivers. Hybrids between farm escapes and established trout were present in all rivers at frequencies ranging between 7 and 69%, and population admixture was positively correlated with genetic diversity. We suggest that non-native salmonids introduced into the Southern Hemisphere could benefit from admixture because local adaptations may not have yet developed, and there may be initially little fitness loss resulting from outbreeding depression. PMID:25568013

  12. Effects of (V + A)-, S-, T-interaction admixtures and of a time reversal invariance violation on the first-forbidden beta-decay of RaE

    International Nuclear Information System (INIS)

    The shape factor and the electron longitudinal polarization of RaE have been calculated under the assumption of (V + A)-, S-, T-interaction admixtures. In addition the influence of a time reversal invariance violation has been considered. It is shown that the effect of (V + A) admixtures on the electron longitudinal polarization is enhanced by two orders of magnitude compared to the case of allowed transitions. Such an effect is also observed for the shape factor. It is also demonstrated that a time reversal invariance violation also affects the observables mentioned above. (orig.)

  13. Bone scanning in osteoporosis

    International Nuclear Information System (INIS)

    This paper reports on bone scanning in osteoporosis a diagnosis of osteoporosis most often follows fracture, and clearly this should be confirmed by x-ray. The bone scan therefore does not have an important role to play in the initial diagnosis of osteoporosis. While the exact mechanism by which the 99mTc-labeled diphosphonates localize in the skeleton is not fully understood, it is believed that they adsorb onto bone surfaces most probably via the calcium of hydroxyapatite crystals. Because the major factors that affect adsorption are osteoblastic activity and to a lesser extent skeletal vascularity, it is apparent that a bone scan image presents a functional display of skeletal metabolic activity. However, osteoporosis is a disorder in which gradual change in bone mass may occur over many years and, in keeping with this minor imbalance in skeletal metabolism, the bone scan appearances are usually normal. However, the scan images may appear of poor quality because of relatively low bone uptake of tracer with, on occasion, a washed-out pattern of activity in the axial and appendicular bone. It has been suggested that such a pattern occurs in severe or end-stage osteoporosis caused by markedly reduced osteoblastic activity. If kyphosis is observed on the bone scan or if there appears to be loss of spinal height with proximity of ribs to each other or increased closeness of rib cage to pelvis, then appearances suggest vertebral collapse and would be in keeping with a diagnosis of osteoporosis. Such evidence is, however, indirect and in practice a bone scan is an extremely unreliable means of diagnosing osteoporosis

  14. Bone scan in pediatrics

    International Nuclear Information System (INIS)

    In 1984, a survey carried out in 21 countries in Europe showed that bone scintigraphy comprised 16% of all paediatric radioisotope scans. Although the value of bone scans in paediatrics is potentially great, their quality varies greatly, and poor-quality images are giving this valuable technique a bad reputation. The handling of children requires a sensitive staff and the provision of a few simple inexpensive items of distraction. Attempting simply to scan a child between two adult patients in a busy general department is a recipe for an unhappy, uncooperative child with the probable result of poor images. The intravenous injection of isotope should be given adjacent to the gamma camera room, unless dynamic scans are required, so that the child does not associate the camera with the injection. This injection is best carried out by someone competent in paediatric venipunture; the entire procedure should be explained to the child and parent, who should remain with child throughout. It is naive to think that silence makes for a cooperative child. The sensitivity of bone-seeking radioisotope tracers and the marked improvement in gamma camera resolution has allowed the bone scanning to become an integrated technique in the assessment of children suspected of suffering from pathological bone conditions. The tracer most commonly used for routine bone scanning is 99mTc diphosphonate (MDP); other isotopes used include 99mTc colloid for bone marrow scans and 67Ga citrate and 111In white blood cells (111In WBC) for investigation of inflammatory/infective lesions

  15. Lung Ventilation/Perfusion Scan

    Science.gov (United States)

    ... two types of scans: ventilation and perfusion. The ventilation scan shows where air flows in your lungs. The perfusion scan shows where blood flows in your lungs. Both scans use radioisotopes (a low-risk radioactive substance). For the ventilation scan, you ...

  16. Scanning Probe Microscopy and Spectroscopy

    Science.gov (United States)

    Wiesendanger, Roland

    1994-09-01

    Preface; List of acronyms; Introduction; Part I. Experimental Methods and Theoretical Background of Scanning Probe Microscopy and Spectroscopy: 1. Scanning tunnelling microscopy; 2. Scanning force microscopy; 3. Related scanning probe techniques; Part II. Applications of Scanning Probe Microscopy and Spectroscopy: 4. Condensed matter physics; 5. Chemistry; 6. Organic materials; 7. Metrology and standards; 8. Nanotechnology; References; Index.

  17. Scanning high-Tc SQUID imaging system for magnetocardiography

    International Nuclear Information System (INIS)

    A scanning magnetocardiography (MCG) system constructed from SQUID sensors offers potential to basic or clinical research in biomagnetism. In this work, we study a first order scanning electronic high-Tc (HTS) SQUID MCG system for biomagnetic signals. The scanning MCG system was equipped with an x-y translation bed powered by step motors. Using noise cancellation and μ-metal shielding, we reduced the noise level substantially. The established scanning HTS MCG system was used to study the magnetophysiology of hypercholesterolaemic (HC) rabbits. The MCG data of HC rabbits were analysed. The MCG contour map of HC rabbits provides experimental models for the interpretation of human cardiac patterns

  18. Map Projection

    CERN Document Server

    Ghaderpour, Ebrahim

    2014-01-01

    In this paper, we introduce some known map projections from a model of the Earth to a flat sheet of paper or map and derive the plotting equations for these projections. The first fundamental form and the Gaussian fundamental quantities are defined and applied to obtain the plotting equations and distortions in length, shape and size for some of these map projections.

  19. Lung scans and malignancy

    International Nuclear Information System (INIS)

    An experience of pulmonary isotope scanning carried out with mercury 197 labelled mercury chloride and acetate, cobalt 57-labelled bleomycin, and Cu67 and Cu64 labelled copper citrate was presented. The scans were carried out with various isotopes supplied by the French Atomic Energy Authority, and gave comparable results, which may be summarised as follows: increased uptake in more than 90% of cases of carcinoma, absent uptake in all cases of benign tumour, frequent increased uptake in acute or advanced inflammatory lesions, absence of uptake, very commonly, in tuberculoma and chronic lesions with scar formation. Radio-isotope scan using Cu67 labelled copper citrate permitted discrimination of malignant tumours (increased fixation which showed up best at the 24th hour) from inflammatory lesions (increased fixation which was reduced on the 24th hour). The positive or negative character of the fixation in a given lesions remains the same, whatever the isotope used in our experience

  20. Harmonic Maps and Biharmonic Maps

    OpenAIRE

    Hajime Urakawa

    2015-01-01

    This is a survey on harmonic maps and biharmonic maps into (1) Riemannian manifolds of non-positive curvature, (2) compact Lie groups or (3) compact symmetric spaces, based mainly on my recent works on these topics.

  1. Consistent long-range linkage disequilibrium generated by admixture in a Bantu-Semitic hybrid population

    OpenAIRE

    Wilson, J F; Goldstein, D. B.

    2000-01-01

    Both the optimal marker density for genome scans in case-control association studies and the appropriate study design for the testing of candidate genes depend on the genomic pattern of linkage disequilibrium (LD). In this study, we provide the first conclusive demonstration that the diverse demographic histories of human populations have produced dramatic differences in genomewide patterns of LD. Using a panel of 66 markers spanning the X chromosome, we show that, in the Lemba, a Bantu-Semit...

  2. Bone scan in rheumatology

    International Nuclear Information System (INIS)

    In this chapter a revision is made concerning different uses of bone scan in rheumatic diseases. These include reflex sympathetic dystrophy, osteomyelitis, spondyloarthropaties, metabolic bone diseases, avascular bone necrosis and bone injuries due to sports. There is as well some comments concerning pediatric pathology and orthopedics. (authors). 19 refs., 9 figs

  3. Scanning bubble chamber pictures

    CERN Multimedia

    1974-01-01

    These were taken at the 2 m hydrogen bubble chamber. The photo shows an early Shiva system where the pre-measurements needed to qualify the event were done manually (cf photo 7408136X). The scanning tables were located in bld. 12. Gilberte Saulmier sits on foreground, Inge Arents at centre.

  4. Getting a CAT Scan

    Medline Plus

    Full Text Available ... The scan itself is painless. All you'll need to do is hold still for a few minutes at a time so the pictures come out clear ... the Nemours Web site. Note: All information on KidsHealth® is for educational purposes only. For ...

  5. Scan This Book!

    Science.gov (United States)

    Albanese, Andrew Richard

    2007-01-01

    In this article, the author presents an interview with Brewster Kahle, leader of the Open Content Alliance (OCA). OCA book scan program is an alternative to Google's library project that aims to make books accessible online. In this interview, Kahle discusses his views on the challenges of getting books on the Web, on Google's library…

  6. Surface micromachined scanning mirrors

    DEFF Research Database (Denmark)

    Mattsson, Kent Erik

    Both aluminum cantilever and torsional scanning mirrors have been fabricated and their static and dynamic properties are studied experimentally and theoretically. The experiments showed resonance frequencies in the range of 163 k-Hz - 632 kHz for cantilever beams with Q values between 5 and 11. T...

  7. Lung gallium scan

    Science.gov (United States)

    ... Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team. Related MedlinePlus Health Topics Lung Diseases Nuclear Scans Sarcoidosis Browse the Encyclopedia A.D.A. ...

  8. A new scanning proton microprobe with long focus

    International Nuclear Information System (INIS)

    A new scanning proton microprobe equipped with a long focus Russian magnetic quadruplet is set up. With excellent performances of ion optics, it can be used to do experiments of PIXE, RBS, RFS, NRA and channelling simultaneously within a micron-region. The power supplies for quadruplet and scanning coils are controlled by an IBM-PC computer and a scanning graphical monitor based on an Apple IIe microcomputer provides convenience of searching for an interesting area to scan. The advanced modes of the fast random scan and the event-by-event data collection make it possible to treat the multi-parameter and multi-detector data by means of the strategy of TQSA (Total quantitative scanning analysis). There are three types of graphical display including the innovation of three dimensional contour mapping

  9. Chemical, physical and engineering characterization of candidate backfill clays and clay admixtures for a nuclear waste repository-Part I

    International Nuclear Information System (INIS)

    Fourteen Canadian clays and clay admixtures were subjected to simulated nuclear waste repository environments. The present work is concerned with the montmorillonite-dominant materials only. The montmorillonite-dominant samples showed significant leaching on interaction with deionized water. On heating the samples at 2000C for 500 hours, montmorillonites lost intermicellar water completely and acquired cusp-like to cylindrical morphologies. The loss of water and the morphological changes in montmorillonites significantly altered the engineering characteristics. Permeability, shrinkage limits, compactability and shear strength varied in response to the dominant exchange cation in the structure of montmorillonites and the presence of other mineral components in the materials. The synthetic granite water reacted with montmorillonites and led to changes in chemical and mineralogical compositions, crystalline state and engineering properties. 12 figures, 9 tables

  10. Survey and coping strategies for job stress of new nurses in pharmacy intravenous admixture service: a pilot study.

    Science.gov (United States)

    Wang, Feng-Shuang; Jin, Ou; Feng, Hua; Wang, Feng-Hua; Ren, Chun-Hui

    2015-01-01

    To survey the nurse stress and analyze stressors in new nurses from pharmacy intravenous admixture service (PIAS). A questionnaire survey referring to the revised stressor scale was carried out on 52 new nurses of PIAS in four hospitals in Harbin. The average stress score for all participants was 2.43±0.63, as medium level of stress. The stressors were classified into 6 categories: ensuring up-to-date knowledge of professional nursing skills, increased workload and work-time, interpersonal relationship, ensuring knowledge of equipments, attending educational programs, and decreased occupational demand. The most important stressors included fear of medical accident occurrence, fear of failure in performance assessment, fear of occupational injuries, feeling fatigue and lack of sleep. Considering the various kinds of stressors in the working places, it was necessary for managers' to use appropriate strategies to cope with the job stress in new nurses of PIAS. PMID:26770583

  11. Phylogeographic Analyses of American Black Bears (Ursus americanus) Suggest Four Glacial Refugia and Complex Patterns of Postglacial Admixture.

    Science.gov (United States)

    Puckett, Emily E; Etter, Paul D; Johnson, Eric A; Eggert, Lori S

    2015-09-01

    Studies of species with continental distributions continue to identify intraspecific lineages despite continuous habitat. Lineages may form due to isolation by distance, adaptation, divergence across barriers, or genetic drift following range expansion. We investigated lineage diversification and admixture within American black bears (Ursus americanus) across their range using 22 k single nucleotide polymorphisms and mitochondrial DNA sequences. We identified three subcontinental nuclear clusters which we further divided into nine geographic regions: Alaskan (Alaska-East), eastern (Central Interior Highlands, Great Lakes, Northeast, Southeast), and western (Alaska-West, West, Pacific Coast, Southwest). We estimated that the western cluster diverged 67 ka, before eastern and Alaskan divergence 31 ka; these divergence dates contrasted with those from the mitochondrial genome where clades A and B diverged 1.07 Ma, and clades A-east and A-west diverged 169 ka. We combined estimates of divergence timing with hindcast species distribution models to infer glacial refugia for the species in Beringia, Pacific Northwest, Southwest, and Southeast. Our results show a complex arrangement of admixture due to expansion out of multiple refugia. The delineation of the genomic population clusters was inconsistent with the ranges for 16 previously described subspecies. Ranges for U. a. pugnax and U. a. cinnamomum were concordant with admixed clusters, calling into question how to order taxa below the species level. Additionally, our finding that U. a. floridanus has not diverged from U. a. americanus also suggests that morphology and genetics should be reanalyzed to assess taxonomic designations relevant to the conservation management of the species. PMID:25989983

  12. Experimental Research on Polycarboxylic Slump-retaining Admixture%聚羧酸减水剂的试验研究

    Institute of Scientific and Technical Information of China (English)

    廖国胜; 艾涛; 肖煜; 潘会

    2014-01-01

    Adopting methyl allyl polyoxyethylene ether (TPEG)and unsaturated carboxylic acid throught REDOX system synthetize the polycarboxylic slump-retaining admixture.The impact factors were researched of temperature,re-action time,acid alcohol ratio,dosage of initiator and molecular regulator to the polycarboxylic superplasticizer with slump retaining.In the circumstance of n(AA)∶n(Itaconic acid)∶n(Thioglycolic acid)∶n(TPEG)=1.7∶0.23∶0.005∶1,m(initiator)∶m(TPEG)=0.20%,reaction time is 4 h and temperaure is 45 ℃,the admixture has the best performance.%采用甲基烯丙基聚氧乙烯醚(TPEG)与不饱和羧酸在氧化还原体系下合成聚羧酸减水剂。研究了反应温度、反应时间、单体与不饱和羧酸摩尔比(酸醚比)、引发剂用量及分子量调节剂用量对聚羧酸减水剂性能的影响。在n(AA)∶n(Itaconic acid)∶n(Thioglycolic acid)∶n(TPEG)=1.7∶0.23∶0.005∶1,m(initiator)∶m(TPEG)=0.20%、反应时间4 h、反应温度45℃时,聚羧酸减水剂各项性能最佳。

  13. Multispecies Outcomes of Sympatric Speciation after Admixture with the Source Population in Two Radiations of Nicaraguan Crater Lake Cichlids

    Science.gov (United States)

    Kautt, Andreas F.; Machado-Schiaffino, Gonzalo; Meyer, Axel

    2016-01-01

    The formation of species in the absence of geographic barriers (i.e. sympatric speciation) remains one of the most controversial topics in evolutionary biology. While theoretical models have shown that this most extreme case of primary divergence-with-gene-flow is possible, only a handful of accepted empirical examples exist. And even for the most convincing examples uncertainties remain; complex histories of isolation and secondary contact can make species falsely appear to have originated by sympatric speciation. This alternative scenario is notoriously difficult to rule out. Midas cichlids inhabiting small and remote crater lakes in Nicaragua are traditionally considered to be one of the best examples of sympatric speciation and lend themselves to test the different evolutionary scenarios that could lead to apparent sympatric speciation since the system is relatively small and the source populations known. Here we reconstruct the evolutionary history of two small-scale radiations of Midas cichlids inhabiting crater lakes Apoyo and Xiloá through a comprehensive genomic data set. We find no signs of differential admixture of any of the sympatric species in the respective radiations. Together with coalescent simulations of different demographic models our results support a scenario of speciation that was initiated in sympatry and does not result from secondary contact of already partly diverged populations. Furthermore, several species seem to have diverged simultaneously, making Midas cichlids an empirical example of multispecies outcomes of sympatric speciation. Importantly, however, the demographic models strongly support an admixture event from the source population into both crater lakes shortly before the onset of the radiations within the lakes. This opens the possibility that the formation of reproductive barriers involved in sympatric speciation was facilitated by genetic variants that evolved in a period of isolation between the initial founding

  14. Brain mapping

    Directory of Open Access Journals (Sweden)

    Blaž Koritnik

    2004-08-01

    Full Text Available Cartography of the brain ("brain mapping" aims to represent the complexities of the working brain in an understandable and usable way. There are four crucial steps in brain mapping: (1 acquiring data about brain structure and function, (2 transformation of data into a common reference, (3 visualization and interpretation of results, and (4 databasing and archiving. Electrophysiological and functional imaging methods provide information about function of the human brain. A prerequisite for multisubject, multidimensional and multimodal mapping is transformation of individual images to match a standard brain template. To produce brain maps, color, contours, and other visual cues are used to differentiate metabolic rates, electrical field potentials, receptor densities, and other attributes of structure or function. Databases are used to organize and archive data records. By relating the maps to cognitive functions and psychological models, brain mapping offers a prerequisite for the understanding of organizational principles of the human brain.

  15. Affective Maps

    DEFF Research Database (Denmark)

    Salovaara-Moring, Inka

    Recently, in human geography there has been a considerable attention paid to retheorising maps; less as a product and more as practice. This refers to the notion that rather than reading maps as fixed representations, digital mapping is by nature a dynamic, performative, and participatory practice....... In particular, mapping environmental damage, endangered species, and human made disasters has become one of the focal point of affective knowledge production. These ‘more-than-humangeographies’ practices include notions of species, space and territory, and movement towards a new political ecology...

  16. Kohonen's feature maps for fly ash categorization.

    Science.gov (United States)

    Nataraja, M C; Jayaram, M A; Ravikumar, C N

    2006-12-01

    Fly ash is a common admixture used in concrete and may constitute up to 50% by weight of the total binder material. Incorporation of fly ash in Portland-cement concrete is highly desirable due to technological, economic, and environmental benefits. This article demonstrates the use of artificial intelligence neural networks for the classification of fly ashes in to different groups. Kohonen's Self Organizing Feature Maps is used for the purpose. As chemical composition of fly ash is crucial in the performance of concrete, eight chemical attributes of fly ashes have been considered. The application of simple Kohonen's one-dimensional feature maps permitted to differentiate three main groups of fly ashes. Three one-dimensional feature maps of topology 8-16, 8-24 and 8-32 were explored. The overall classification result of 8-16 topology was found to be significant and encouraging. The data pertaining to 80 fly ash samples were collected from standard published works. The categorization was found to be excellent and compares well with Canadian Standard Association's [CSA A 3000] classification scheme. PMID:17285691

  17. 67Ga lung scan

    International Nuclear Information System (INIS)

    Twenty-three patients with clinical signs of pulmonary embolic disease and lung infiltrates were studied to determine the value of gallium citrate 67Ga lung scan in differentiating embolic from inflammatory lung disease. In 11 patients without angiographically proved embolism, only seven had corresponding ventilation-perfusion defects compatible with inflammatory disease. In seven of these 11 patients, the 67Ga concentration indicated inflammatory disease. In the 12 patients with angiographically proved embolic disease, six had corresponding ventilation-perfusion defects compatible with inflammatory disease. None had an accumulation of 67Ga in the area of pulmonary infiltrate. Thus, ventilation-perfusion lung scans are of limited value when lung infiltrates are present. In contrast, the accumulation of 67Ga in the lung indicates an inflammatory process. Gallium imaging can help select those patients with lung infiltrates who need angiography

  18. Adrenal scanning in children

    International Nuclear Information System (INIS)

    Adrenal scanning with 131I-Adosterol is very useful and rather non-invasive than adrenal angiography in children. It is possible to diagnose various diseases of the adrenal glands not only structural but also functional abnormalities. In patients with adrenogenital syndromes, we are able to demonstrate hyperplasia of the adrenal glands, and in patients with aldosteronism or Cushing's syndrome differential diagnosis between bilateral hyperplasia and functional adenoma of the adrenal gland can be made. (author)

  19. Energy Scan program

    Directory of Open Access Journals (Sweden)

    Poniatowska Katarzyna M.

    2014-04-01

    Full Text Available Femtoscopy of two non-identical particles in heavy ion collisions enables one to study the space-time asymmetry in the particle's emission process. Theoretical studies based on EPOS model performed for collision energies from the Beam Energy Scan program in STAR allow us to investigate the dependence of source sizes and dynamics effects. Obtained information will enable us to predict the collective behaviour of femtoscopic particle's source.

  20. Forensic Scanning Electron Microscope

    Science.gov (United States)

    Keeley, R. H.

    1983-03-01

    The scanning electron microscope equipped with an x-ray spectrometer is a versatile instrument which has many uses in the investigation of crime and preparation of scientific evidence for the courts. Major applications include microscopy and analysis of very small fragments of paint, glass and other materials which may link an individual with a scene of crime, identification of firearms residues and examination of questioned documents. Although simultaneous observation and chemical analysis of the sample is the most important feature of the instrument, other modes of operation such as cathodoluminescence spectrometry, backscattered electron imaging and direct x-ray excitation are also exploited. Marks on two bullets or cartridge cases can be compared directly by sequential scanning with a single beam or electronic linkage of two instruments. Particles of primer residue deposited on the skin and clothing when a gun is fired can be collected on adhesive tape and identified by their morphology and elemental composition. It is also possible to differentiate between the primer residues of different types of ammunition. Bullets may be identified from the small fragments left behind as they pass through the body tissues. In the examination of questioned documents the scanning electron microscope is used to establish the order in which two intersecting ink lines were written and to detect traces of chemical markers added to the security inks on official documents.

  1. Automatic color map digitization by spectral classification

    Science.gov (United States)

    Chu, N. Y.; Anuta, P. E.

    1979-01-01

    A method of converting polygon map information into a digital form which does not require manual tracing of polygon edges is discussed. The maps must be in color-coded format with a unique color for each category in the map. Color scanning using a microdensitometer is employed and a three-channel color separation digital data set is generated. The digital data are then classified by using a Gaussian maximum likelihood classifier, and the resulting digitized map is evaluated. Very good agreement is observed between the classified and original map.

  2. Scanning measurement of Seebeck coefficient of a heated sample

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, G. Jeffrey; Iwanaga, Shiho

    2016-04-19

    A novel scanning Seebeck coefficient measurement technique is disclosed utilizing a cold scanning thermocouple probe tip on heated bulk and thin film samples. The system measures variations in the Seebeck coefficient within the samples. The apparatus may be used for two dimensional mapping of the Seebeck coefficient on the bulk and thin film samples. This technique can be utilized for detection of defective regions, as well as phase separations in the sub-mm range of various thermoelectric materials.

  3. Mapping Inhibitory Neuronal Circuits by Laser Scanning Photostimulation

    OpenAIRE

    Ikrar, Taruna; Olivas, Nicholas D.; Shi, Yulin; Xu, Xiangmin

    2011-01-01

    Inhibitory neurons are crucial to cortical function. They comprise about 20% of the entire cortical neuronal population and can be further subdivided into diverse subtypes based on their immunochemical, morphological, and physiological properties1-4. Although previous research has revealed much about intrinsic properties of individual types of inhibitory neurons, knowledge about their local circuit connections is still relatively limited3,5,6. Given that each individual neuron's function is s...

  4. Applications of orientation mapping by scanning and transmission electron microscopy

    DEFF Research Database (Denmark)

    Juul Jensen, D.

    1997-01-01

    , focus is on cold deformation and recrystallization processes. It is described how the OIM techniques may be applied for studies of such processes. Results of OIM measurements supplement more traditional TEM and SEM microstructure characterizations as well as bulk texture measurements, and new...

  5. Novel approach to stationary transmission scanning using Compton scattered radiation

    International Nuclear Information System (INIS)

    Transmission scanning-based estimation of the attenuation map plays a crucial role in quantitative radionuclide imaging. X-ray computed tomography (CT) reconstructs directly the attenuation coefficients map from data transmitted through the object. This paper proposes an alternative route for reconstructing the object attenuation map by exploiting Compton scatter of transmitted radiation from an externally placed radionuclide source. In contrast to conventional procedures, data acquisition is realized as a series of images parameterized by the Compton scattering angle and registered on a stationary gamma camera operating without spatial displacement. Numerical simulation results using realistic voxel-based phantoms are presented to illustrate the efficiency of this new transmission scanning approach for attenuation map reconstruction. The encouraging results presented in this paper may suggest the possibility of proposing a new concept for emission/transmission imaging using scattered radiation, which has many advantages compared to conventional technologies

  6. Cognitive maps

    DEFF Research Database (Denmark)

    Minder, Bettina; Laursen, Linda Nhu; Lassen, Astrid Heidemann

    2014-01-01

    . Conceptual clustering is used to analyse and order information according to concepts or variables from within the data. The cognitive maps identified are validated through the comments of some of the same experts. The study presents three cognitive maps and respective world-views explaining how the design...

  7. Causal mapping

    DEFF Research Database (Denmark)

    Rasmussen, Lauge Baungaard

    2006-01-01

    The lecture note explains how to use the causal mapping method as well as the theoretical framework aoosciated to the method......The lecture note explains how to use the causal mapping method as well as the theoretical framework aoosciated to the method...

  8. The Scanning TMR Microscope for Biosensor Applications

    Directory of Open Access Journals (Sweden)

    Kunal N. Vyas

    2015-04-01

    Full Text Available We present a novel tunnel magnetoresistance (TMR scanning microscopeset-up capable of quantitatively imaging the magnetic stray field patterns of micron-sizedelements in 3D. By incorporating an Anderson loop measurement circuit for impedancematching, we are able to detect magnetoresistance changes of as little as 0.006%/Oe. By 3Drastering a mounted TMR sensor over our magnetic barcodes, we are able to characterisethe complex domain structures by displaying the real component, the amplitude and thephase of the sensor’s impedance. The modular design, incorporating a TMR sensor withan optical microscope, renders this set-up a versatile platform for studying and imagingimmobilised magnetic carriers and barcodes currently employed in biosensor platforms,magnetotactic bacteria and other complex magnetic domain structures of micron-sizedentities. The quantitative nature of the instrument and its ability to produce vector maps ofmagnetic stray fields has the potential to provide significant advantages over other commonlyused scanning magnetometry techniques.

  9. The KFUPM scanning nuclear microprobe facility

    International Nuclear Information System (INIS)

    The scanning nuclear microprobe facility recently installed on the tandetron accelerator of King Fahd University of Petroleum and Minerals in Dhahran, Saudi Arabia is described. The design is based on the Oxford magnetic quadrupole triplet lens system and can focus a beam of 2.5 MeV protons to a spot of about 1 μm diameter with a current of about 100 pA. Maximum scanning area is at present limited to 130 μm by 100 μm. Acceptance tests performed during the commissioning of the facility are discussed. Elemental maps of a catalyst by PIXE measurements are given to demonstrate the performance of the system. (orig.)

  10. Multiplatform Mobile Laser Scanning: Usability and Performance

    Directory of Open Access Journals (Sweden)

    Yuwei Chen

    2012-08-01

    Full Text Available Mobile laser scanning is an emerging technology capable of capturing three-dimensional data from surrounding objects. With state-of-the-art sensors, the achieved point clouds capture object details with good accuracy and precision. Many of the applications involve civil engineering in urban areas, as well as traffic and other urban planning, all of which serve to make 3D city modeling probably the fastest growing market segment in this field. This article outlines multiplatform mobile laser scanning solutions such as vehicle- and trolley-operated urban area data acquisition, and boat-mounted equipment for fluvial environments. Moreover, we introduce a novel backpack version of mobile laser scanning equipment for surveying applications in the field of natural sciences where the requirements include precision and mobility in variable terrain conditions. In addition to presenting a technical description of the systems, we discuss the performance of the solutions in the light of various applications in the fields of urban mapping and modeling, fluvial geomorphology, snow-cover characterization, precision agriculture, and in monitoring the effects of climate change on permafrost landforms. The data performance of the mobile laser scanning approach is described by the results of an evaluation of the ROAMER on a permanent MLS test field. Furthermore, an in situ accuracy assessment using a field of spherical 3D targets for the newly-introduced Akhka backpack system is conducted and reported on.

  11. Visualization in Scanning

    International Nuclear Information System (INIS)

    Scanning is essentially a method of making the unknown known, and for the vast majority of scanning work this means making the invisible visible. Visualization is developed as a process involving a model of eye and brain function, display performance and counter performance combined with the spatial frequency components in the object scanned. The performance of a scanner or gamma camera depends in part on its display system and experiments have been performed to determine the fractional change in count-rate which can be perceived by the eye from colour, photoscan and cathode-ray tube displays, for both circular and line sources of radioactivity. For circular sources, colour and photoscan displays are capable of making 10% increases in count-rate perceptible in backgrounds ranging from 5 to 100 counts/s for sources of 1 to 4 cm diameter, whilst cathode-ray tube and black-mark displays show only 20% at best. The results for line sources are also given. In testing for the statistical significance of count-rate differences on a scan, the counts are usually compared for equal areas. On this basis the cathode-ray tube display is only able to show five standard deviations of difference whereas colour and photoscan displays show from 2.5 to 3 standard deviations, levels not usually accepted statistically as significant. It is suggested that if the eye examines the areas surrounding the area of interest then the significance of a count-rate difference may be established more accurately and in general will be increased, thereby accounting for the visualization of apparently 'insignificant' regions. This theory is used to predict the areas of count density which should be visually perceived in the presence of noise, and extended to consider practical display conditions, which have been described in this paper. The performance of a scanner can be considered in terms of its modulation transfer function (derived from a line spread function). Fourier analysis has been performed

  12. Spinal CT scan, 1

    International Nuclear Information System (INIS)

    Methods of CT of the cervical and thoracic spines were explained, and normal CT pictures of them were described. Spinal CT was evaluated in comparison with other methods in various spinal diseases. Plain CT revealed stenosis due to spondylosis or ossification of posterior longitudinal ligament and hernia of intervertebral disc. CT took an important role in the diagnosis of spinal cord tumors with calcification and destruction of the bone. CT scan in combination with other methods was also useful for the diagnosis of spinal injuries, congenital anomalies and infections. (Ueda, J.)

  13. Association Mapping for Drought Tolerance of Rice (Oryza sativa L.) at Vegetative Stage

    Institute of Scientific and Technical Information of China (English)

    Yulong XIAO; Chuanyuan YU; Jianguo LEI; Quirino D; DELA CRUZ; Jonalyn M.YABES; Dindo A.TABANAo

    2012-01-01

    [Objective] This study aimed to identify possible quantitative trait loci (QTL) for vegetative drought tolerance traits of rice (Oryza sativa L.). [Method] A total of 184 rice genotypes were field screened and 156 SSR markers randomly distributed at each 3 Mb bin were used through genome-wide scanning method and association analysis to detect QTLs for vegetative drought tolerance traits leaf rolling (LER), leaf drying (LED) and drought recovery rate (DRR). [Result] The experimental rice geno- types showed varied response under vegetative drought, LER, LED and DRR were highly correlated. Population structure was detected at K=3 and K=7, certain extent of admixture existed in the experimental rice genotypes, relative kinship of the rice genotypes ranged from 0 to 0.924 5. Significant linkage disequilibrium among SSR markers was detected. Sixteen SSR markers have been detected to be associated with vegetative drought tolerance traits, four for LER, eight for LED and four for DDR. Most of the markers were associated with more than one trait, indicating a single mechanism might involve in expression of several related traits, i.e. osmotic adjustment. RM107 (Chr.9) was associated with all the three traits and fell exactly within or closely nearby to previous reported regions, was a major QTL for vegeta- tive drought tolerance, RM477 (Chr.8) was significantly associated with DRR and ex- tremely significantly associated with LER was probably another major QTL for vege- tative drought tolerance. [Conclusion] Association mapping is a very effective method for describing complex traits like drought tolerance.

  14. CALS Mapping

    DEFF Research Database (Denmark)

    Collin, Ib; Nielsen, Povl Holm; Larsen, Michael Holm

    1998-01-01

    To enhance the industrial applications of CALS, CALS Center Danmark has developed a cost efficient and transparent assessment, CALS Mapping, to uncover the potential of CALS - primarily dedicated to small and medium sized enterprises. The idea behind CALS Mapping is that the CALS State of the...... enterprise is, when applied in a given organisation modified with respect to the industry regarded, hence irrelevant measure parameters are eliminated to avoid redundancy. This assessment of CALS Mapping, quantify the CALS potential of an organisation with the purpose of providing decision support to the top...

  15. Nuclear Medicine Scans for Cancer

    Science.gov (United States)

    ... My ACS » Your Local Offices Close + - Text Size Nuclear Medicine Scans for Cancer Other names for these ... inflammation, or cancer. Use of monoclonal antibodies in nuclear scans A special type of antibody made in ...

  16. Demonstration of scan path optimization in proton therapy

    International Nuclear Information System (INIS)

    A three-dimensional (3D) intensity modulated proton therapy treatment plan to be delivered by magnetic scanning may comprise thousands of discrete beam positions. This research presents the minimization of the total scan path length by application of a fast simulated annealing (FSA) optimization algorithm. Treatment plans for clinical prostate and head and neck cases were sequenced for continuous raster scanning in two ways, and the resulting scan path lengths were compared: (1) A simple back-and-forth, top-to-bottom (zigzag) succession, and (2) an optimized path produced as a solution of the FSA algorithm. Using a first approximation of the scanning dynamics, the delivery times for the scan sequences before and after path optimization were calculated for comparison. In these clinical examples, the FSA optimization shortened the total scan path length for the 3D target volumes by approximately 13%-56%. The number of extraneous spilled particles was correspondingly reduced by about 13%-54% due to the more efficient scanning maps that eliminated multiple crossings through regions of zero fluence. The relative decrease in delivery time due to path length minimization was estimated to be less than 1%, due to both a high scanning speed and time requirements that could not be altered by optimization (e.g., time required to change the beam energy). In a preliminary consideration of application to rescanning techniques, the decrease in delivery time was estimated to be 4%-20%

  17. Scanned-cantilever atomic force microscope with large scanning range

    Institute of Scientific and Technical Information of China (English)

    Jintao Yang; Wendong Xu

    2006-01-01

    A scanned-cantilever atomic force microscope (AFM) with large scanning range is proposed, which adopts a new design named laser spot tracking. The scanned-cantilever AFM uses the separate flexure x-y scanner and z scanner instead of the conventional piezoelectric tube scanner. The closed-loop control and integrated capacitive sensors of these scanners can insure that the images of samples have excellent linearity and stability. According to the experimental results, the scanned-cantilever AFM can realize maximal 100 × 100 (μm) scanning range, and 1-nm resolution in z direction, which can meet the requirements of large scale sample testing.

  18. Participatory maps

    DEFF Research Database (Denmark)

    Salovaara-Moring, Inka

    towards a new political ecology. This type of digital cartographies has been highlighted as the ‘processual turn’ in critical cartography, whereas in related computational journalism it can be seen as an interactive and iterative process of mapping complex and fragile ecological developments. This paper......There has recently been considerable attention paid to digital, spatial visualisations in digital journalism and technology studies; less as a product and more as practice. This refers to the notion that rather than reading maps as fixed representations, digital mapping is by nature a dynamic...... is defined as a digitally created affective (map)space within which journalistic practice can be seen as dynamic, performative interactions between journalists, ecosystems, space, and species....

  19. Composts with and without wood ash admixture for the management of tropical acid soils: chemical, physical and microbiological effects

    Science.gov (United States)

    Bougnom, B. P.; Insam, H.; Etoa, F. X.

    2009-04-01

    Acid soils generally found in the tropics have a low pH, are poor in organic matter, deficient in Ca2+, Mg+, P, or Mo ; limited in mineralization, nitrification, nodulation, and mycorrhizal infection , suffer from Al or Mn toxicity. Within the framework aiming at using organic wastes and wood ash to overcome soil infertility in tropical acidic soils, a green house experiment was conducted with two acid soils collected from Cameroon (Ferralsol and Acrisol) and amended with three types of compost 3:1(W/W) containing 0 (K0), 8(K8) and 16% (K16) wood ash admixture respectively for two consecutive cycles of 100 days, during which soybean (Glycine max) was grown on the first, the second cycle was left as fallow. Generally the same trends of variation of the physico-chemical parameters were observed in both soils. Addition of organic wastes increased the pH electrical conductivity, soil organic matter, water holding capacity, total Carbone and total nitrogen as compared to the controls. The rate of nitrification highly increased posing the problem of possible leaching of nitrates in the ground water. The cations and micronutrients content followed the same trends. These changes leaded to an increase of the P availability and a decrease of Al toxicity. At the end of the second cycle, generally most of the different parameters slightly decreased except for the electrical conductivity. All composts passed a toxicity test, and the amended soils had significant better fresh and dried plant biomass, the Total nitrogen also significantly increased. Amended soils with K0 generally performed better than those amended with K8 and K16, thinking that their pH (closer to the neutrality) was responsible of these performances, all the parameters were significantly correlated to the pH. K8 and K16 performances could be performed by reducing the added quantities. The study of PCR-DGGE have shown a shift in the fungal and bacterial communities, Ammonia oxidizing bacteria community were

  20. Brain mapping

    OpenAIRE

    Blaž Koritnik

    2004-01-01

    Cartography of the brain ("brain mapping") aims to represent the complexities of the working brain in an understandable and usable way. There are four crucial steps in brain mapping: (1) acquiring data about brain structure and function, (2) transformation of data into a common reference, (3) visualization and interpretation of results, and (4) databasing and archiving. Electrophysiological and functional imaging methods provide information about function of the human brain. A prere...

  1. Noise map

    OpenAIRE

    Němcová, Michaela

    2015-01-01

    The aim of this paper is to introduce the measurement of noise and create a noise map in a geographic information system. The first part is focused on describing the physical properties of sound in space, atmospheric and physiological acoustics. It also deals with the physiological effects of noise on the human body and technology needed for measure and process noise. Other part describes the structure of a geographic information system and noise map. The last part is about the practical crea...

  2. Rethinking maps

    OpenAIRE

    Kitchin, Rob; Dodge, Martin

    2007-01-01

    In this paper we argue that cartography is profitably conceived as a processual, rather than representational, science. Building on recent analysis concerning the philosophical underpinnings of cartography we question the ontological security of maps, contending that it is productive to rethink cartography as ontogenetic in nature; that is maps emerge through practices and have no secure ontological status. Drawing on the concepts of transduction and technicity we contend that ...

  3. Standard test method for determining effects of chemical admixtures on corrosion of embedded steel reinforcement in concrete exposed to chloride environments

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This test method covers a procedure for determining the effects of chemical admixtures on the corrosion of metals in concrete. This test method can be used to evaluate materials intended to inhibit chloride-induced corrosion of steel in concrete. It can also be used to evaluate the corrosivity of admixtures in a chloride environment. 1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  4. The isospin admixture of the ground state and the properties of the isobar analog resonances in medium and heavy mass nuclei

    Indian Academy of Sciences (India)

    D I Salmov; T Babacan; A Kücükbursa; S Ünlü; İ Maraṣ

    2006-06-01

    Within the framework of quasiparticle random phase approximation (QRPA), Pyatov–Salamov method [23] for the self-consistent determination of the isovector effective interaction strength parameter, restoring a broken isotopic symmetry for the nuclear part of the Hamiltonian, is used. The isospin admixtures in the ground state of the parent nucleus, and the isospin structure of the isobar analog resonance (IAR) state were investigated with the inclusion of the pairing correlations between nucleons for the medium and heavy mass regions: 80 < < 90, 102 < < 124, and 204 < < 214. It was determined that the influence of the pairing interaction between nucleons on the isospin admixtures in the ground state and the isospin structure of the IAR state is more pronounced for the light isotopes ( ≈ ) of the investigated nuclei.

  5. Quadrature wavelength scanning interferometry.

    Science.gov (United States)

    Moschetti, Giuseppe; Forbes, Alistair; Leach, Richard K; Jiang, Xiang; O'Connor, Daniel

    2016-07-10

    A novel method to double the measurement range of wavelength scanning interferometery (WSI) is described. In WSI the measured optical path difference (OPD) is affected by a sign ambiguity, that is, from an interference signal it is not possible to distinguish whether the OPD is positive or negative. The sign ambiguity can be resolved by measuring an interference signal in quadrature. A method to obtain a quadrature interference signal for WSI is described, and a theoretical analysis of the advantages is reported. Simulations of the advantages of the technique and of signal errors due to nonideal quadrature are discussed. The analysis and simulation are supported by experimental measurements to show the improved performances. PMID:27409307

  6. The normal bone scan

    International Nuclear Information System (INIS)

    This paper discusses applications of the bone scan. It is the most frequently performed nuclear medicine investigation, the commonest indication being the detection of occult metastases, for which purpose the entire skeleton should be imaged. For other purposes it is often adequate to examine only part of the skeleton. The amount of isotope taken up at any site depends primarily on the local rate of bone turnover rather than on bone mass. The scintigraphic appearance therefore does not necessarily correlate with the radiographic one; however, as there is a relationship between the rate at which bone is replaced and the quantity of bone which is present at any point, the two appearances are not entirely unrelated. Recognition of abnormality is based on a detailed knowledge of normal scintigraphic appearances

  7. Telescopic horizon scanning.

    Science.gov (United States)

    Koenderink, Jan

    2014-12-20

    The problem of "distortionless" viewing with terrestrial telescopic systems (mainly "binoculars") remains problematic. The so called "globe effect" is only partially counteracted in modern designs. Theories addressing the phenomenon have never reached definitive closure. In this paper, we show that exact distortionless viewing with terrestrial telescopic systems is not possible in general, but that it is in principle possible in-very frequent in battle field and marine applications-the case of horizon scanning. However, this involves cylindrical optical elements. For opto-electronic systems, a full solution is more readily feasible. The solution involves a novel interpretation of the relevant constraints and objectives. For final design decisions, it is not necessary to rely on a corpus of psychophysical (or ergonomic) data, although one has to decide whether the instrument is intended as an extension of the eye or as a "pictorial" device. PMID:25608206

  8. A Scanning Cavity Microscope

    CERN Document Server

    Mader, Matthias; Hänsch, Theodor W; Hunger, David

    2014-01-01

    Imaging of the optical properties of individual nanosystems beyond fluorescence can provide a wealth of information. However, the minute signals for absorption and dispersion are challenging to observe, and only specialized techniques requiring sophisticated noise rejection are available. Here we use signal enhancement in a scanning optical microcavity to demonstrate ultra-sensitive imaging. Harnessing multiple interactions of probe light with a sample within an optical resonator, we achieve a 1700-fold signal enhancement compared to diffraction-limited microscopy. We demonstrate quantitative imaging of the extinction cross section of gold nanoparticles with a sensitivity below 1 nm2, we show a method to improve spatial resolution potentially below the diffraction limit by using higher order cavity modes, and we present measurements of the birefringence and extinction contrast of gold nanorods. The demonstrated simultaneous enhancement of absorptive and dispersive signals promises intriguing potential for opt...

  9. Micro scanning probes

    CERN Document Server

    Niblock, T

    2001-01-01

    This thesis covers the design methodology, theory, modelling, fabrication and evaluation of a Micro-Scanning-Probe. The device is a thermally actuated bimorph quadrapod fabricated using Micro Electro Mechanical Systems technology. A quadrapod is a structure with four arms, in this case a planar structure with the four arms forming a cross which is dry etched out of a silicon diaphragm. Each arm has a layer of aluminium deposited on it forming a bimorph. Through heating each arm actuation is achieved in the plane of the quadrapod and the direction normal to it. Fabrication of the device has required the development of bulk micromachining techniques to handle post CMOS fabricated wafers and the patterning of thickly sputtered aluminium in bulk micro machined cavities. CMOS fabrication techniques were used to incorporate diodes onto the quadrapod arms for temperature measurement of the arms. Fine tungsten and silicon tips have also been fabricated to allow tunnelling between the tip and the platform at the centr...

  10. CT scans in encephalitis

    International Nuclear Information System (INIS)

    Generally, CT scans reveal a decrease in the volume of the ventricular system, sylvian fissures and cortical sulci in the acute stage of encephalitis, and softening of the cerebral lobes with dilatation of the lateral ventricles and subarachnoidian dilated spaces in the chronic stage. We encountered three cases of encephalitis: mumps (case 1), herpes simplex (case 2), and syphilis (case 3). In case 1, brain edema was seen in the acute stage and brain atrophy in the chronic stage. In case 2, necrosis of the temporal pole, which is pathognomonic in herpes simplex encephalitis, was recognized. And in case 3, multiple lesions whose CT appearance was enhanced by contrast materials were found scattered over the whole brain. These lesions were diagnosed as inflammatory granuloma by histological examination. (author)

  11. The peopling of São Tomé (Gulf of Guinea): origins of slave settlers and admixture with the Portuguese.

    Science.gov (United States)

    Tomás, Gil; Seco, Luísa; Seixas, Susana; Faustino, Paula; Lavinha, João; Rocha, Jorge

    2002-06-01

    The geographic origins of African slave settlers and the Portuguese genetic contribution to the population of São Tomé (Gulf of Guinea) were assessed through the analysis of beta-globin haplotypes in 44 chromosomes bearing the betaS allele and through the study of the genetic variation in eight autosomal markers (APOA1, AT3, FY, LPL, OCA2, RB1, Sb19.3, and GC) informative for admixture in a sample of 224 individuals. The observed betaS haplotype distribution (36.4% Bantu, 52.3% Benin, 4.5% Cameroon, 4.5% Senegal, and 2.3% atypical) is in accordance with the historical information on the major geographic sources of slave settlers of São Tomé, although it captures a more important contribution of Central-West Africa regions than previously anticipated. European admixture, estimated to be 10.7 +/- 0.9%, has created a considerable level of genetic structure, as indicated by the finding of significant linkage disequilibrium between 33% of unlinked marker loci pairs. Recent admixture was found to have an important contribution to these values, since removal of individuals with Portuguese or Cape Verdian parents or grandparents from the sample dropped the miscegenation level to 6.5 +/- 0.8% and reduced significant linkage disequilibrium to 11% of unlinked marker pairs. Taken together, these results indicate that the peopling of São Tomé might have provided one of the first examples of the combination of diverse African contributions and European admixture that emerged from the overseas population relocations promoted by the Atlantic slave trade. PMID:12180763

  12. Research status of mine tailings used as cement admixture%尾矿作水泥混合材的研究现状

    Institute of Scientific and Technical Information of China (English)

    谭明洋; 吕宪俊; 姜梅芬

    2015-01-01

    概述了近年来尾矿在水泥中的应用及研究现状,并据此提出了今后尾矿用作水泥混合材的研究方向。%Summarized the application status and the up-to-date progress of mine tailings used in cement,and further research topics for the application performance of cement admixtures were proposed accordingly.

  13. Northern range expansion of European populations of the wasp spider Argiope bruennichi is associated with global warming-correlated genetic admixture and population-specific temperature adaptations.

    Science.gov (United States)

    Krehenwinkel, Henrik; Tautz, Diethard

    2013-04-01

    Poleward range expansions are observed for an increasing number of species, which may be an effect of global warming during the past decades. However, it is still not clear in how far these expansions reflect simple geographical shifts of species ranges, or whether new genetic adaptations play a role as well. Here, we analyse the expansion of the wasp spider Argiope bruennichi into Northern Europe during the last century. We have used a range-wide sampling of contemporary populations and historical specimens from museums to trace the phylogeography and genetic changes associated with the range shift. Based on the analysis of mitochondrial, microsatellite and SNP markers, we observe a higher level of genetic diversity in the expanding populations, apparently due to admixture of formerly isolated lineages. Using reciprocal transplant experiments for testing overwintering tolerance, as well as temperature preference and tolerance tests in the laboratory, we find that the invading spiders have possibly shifted their temperature niche. This may be a key adaptation for survival in Northern latitudes. The museum samples allow a reconstruction of the invasion's genetic history. A first, small-scale range shift started around 1930, in parallel with the onset of global warming. A more massive invasion of Northern Europe associated with genetic admixture and morphological changes occurred in later decades. We suggest that the latter range expansion into far Northern latitudes may be a consequence of the admixture that provided the genetic material for adaptations to new environmental regimes. Hence, global warming could have facilitated the initial admixture of populations and this resulted in genetic lineages with new habitat preferences. PMID:23496675

  14. The effects of Propofol-Thiopental admixture on hemodynamic changes, pain on injection, and hypnotic dose at the time of anesthesia induction: a prospective study

    Directory of Open Access Journals (Sweden)

    Soltani Mohammadi S

    2007-09-01

    Full Text Available   Background: Propofol and Thiopental are intravenous anesthetics having relatively different hemodynamic influences and adverse effects. In addition, there is significant pain on intravenous injection of propofol. This study was performed to examine the effects of Propofol-Thiopental admixture on hemodynamic variables, pain on injection and hypnotic dose at the time of induction of general anesthesia.Methods: One hundred and twenty-five ASA I or II patients scheduled for elective surgery were randomized into four groups for induction of anesthesia in a double-blinded manner. With an original concentration of Propofol of 1% and that of Thiopental of 2.5%, we used these drugs in each group as follows: group P100: Propofol alone; group P75: ¾ Propofol and ¼ thiopental (volume/volume; group P50: ½ Propofol and ½ thiopental; group T100: Thiopental alone (control group. Hemodynamic variables (before and after induction, score of pain on injection and hypnotic doses were recorded and statistically analyzed.Results: Admixture of Thiopental and Propofol reduces the injection pain of Propofol, as admixtures P75 and P50 were significantly less painful on injection than P100. Induction of hypnosis was significantly more rapid in group T100 than in groups P100 and P75. The interaction of Propofol and Thiopental with regard to their hypnotic effect is additive. Therefore a reduction in the dose of one was compensated by proportional increase in the dose of the other drug for a hypnotic effect. After anesthesia induction, systolic and diastolic blood pressures were significantly lower in group P100 than in groups P75, P50 and T100. The heart rate after laryngoscopy and tracheal intubation was significantly lower in group P100 than in groups P50 and T100.Conclusion: Propofol-Thiopental admixture causes minimal pain on injection for intravenous induction of anesthesia with modified hemodynamic effects in comparison with each drug when used separately.

  15. Chemical imaging of biological systems with the scanning electrochemical microscope.

    Science.gov (United States)

    Gyurcsányi, Róbert E; Jágerszki, Gyula; Kiss, Gergely; Tóth, Klára

    2004-06-01

    A brief overview on recent advances in the application of scanning electrochemical microscopy (SECM) to the investigation of biological systems is presented. Special emphasis is given to the mapping of local enzyme activity by SECM, which is exemplified by relevant original systems. PMID:15110274

  16. Scanning Emitter Lifetime Imaging Microscopy for Spontaneous Emission Control

    DEFF Research Database (Denmark)

    Frimmer, Martin; Chen, Yuntian; Koenderink, A. Femius

    2011-01-01

    We report an experimental technique to map and exploit the local density of optical states of arbitrary planar nanophotonic structures. The method relies on positioning a spontaneous emitter attached to a scanning probe deterministically and reversibly with respect to its photonic environment whi...

  17. Implementation of ionoluminescence in the AGLAE scanning external microprobe

    Energy Technology Data Exchange (ETDEWEB)

    Pichon, L., E-mail: laurent.pichon@culture.gouv.fr [Centre de recherche et de restauration des musées de France, C2RMF, Palais du Louvre – Porte des Lions, 14 Quai François Mitterrand, 75001 Paris (France); Fédération de recherche NewAGLAE, FR3506 CNRS/Ministère de la Culture/UPMC, Palais du Louvre, 75001 Paris (France); Calligaro, T.; Gonzalez, V. [Centre de recherche et de restauration des musées de France, C2RMF, Palais du Louvre – Porte des Lions, 14 Quai François Mitterrand, 75001 Paris (France); PSL Research University, Chimie ParisTech-CNRS, Institut de Recherche Chimie Paris, UMR8247, 75005 Paris (France); Lemasson, Q.; Moignard, B.; Pacheco, C. [Centre de recherche et de restauration des musées de France, C2RMF, Palais du Louvre – Porte des Lions, 14 Quai François Mitterrand, 75001 Paris (France); Fédération de recherche NewAGLAE, FR3506 CNRS/Ministère de la Culture/UPMC, Palais du Louvre, 75001 Paris (France)

    2015-04-01

    The scope of this work is to present the implementation of an IBIL imaging system in the scanning external microprobe of the AGLAE facility so as to correlate luminescence and composition maps provided by PIXE, RBS and PIGE. The challenging integration of the optical spectrometer, due to incompatibility of acquisition timings and data formats with the other IBA channels has motivated the development of a specific acquisition system. This article details the IBIL setup and explains the technical solutions retained for the coupling of IBIL with IBA techniques in order to produce fast and large IBIL-IBA maps. The IBIL maps stored in the same format as the PIXE, RBS and PIGE ones can be visualised and compared using the dedicated AGLAEmap program or the PyMCA processing package. An example of such a coupled mapping on Mesoamerican jade is presented to emphasise the interest of performing simultaneously IBA and IBIL large mappings.

  18. Implementation of ionoluminescence in the AGLAE scanning external microprobe

    International Nuclear Information System (INIS)

    The scope of this work is to present the implementation of an IBIL imaging system in the scanning external microprobe of the AGLAE facility so as to correlate luminescence and composition maps provided by PIXE, RBS and PIGE. The challenging integration of the optical spectrometer, due to incompatibility of acquisition timings and data formats with the other IBA channels has motivated the development of a specific acquisition system. This article details the IBIL setup and explains the technical solutions retained for the coupling of IBIL with IBA techniques in order to produce fast and large IBIL-IBA maps. The IBIL maps stored in the same format as the PIXE, RBS and PIGE ones can be visualised and compared using the dedicated AGLAEmap program or the PyMCA processing package. An example of such a coupled mapping on Mesoamerican jade is presented to emphasise the interest of performing simultaneously IBA and IBIL large mappings

  19. Progress in Lignin-based Concrete Admixtures%含木质素基混凝土外加剂的研究进展

    Institute of Scientific and Technical Information of China (English)

    谌凡琪

    2012-01-01

    综述了木质素在混凝土外加剂中的应用。工业木质素,尤其是木质素磺酸盐,可以充当混凝土减水剂、缓凝剂、引气剂和泵送剂。由于未经改性的工业木质素性能不够理想,为了提高木质素基混凝土添加剂的性能,宜对其进行适当的改性。碱木质素经过氧化、磺化、磺甲基化、接枝共聚等改性后,可以得到具有良好性能的混凝土外加剂。%The applications of lignin derivatives in concrete admixtures are reviewed. Technical lignins, especially lignosulfonates, can serve as concrete water reducers, retarders, air entraining agents and pumping agents. The performance of lignin is not good. Some appropriate modifications are sometimes required in order to improve the performance of the lignin-based concrete admixtures. Lignin-based concrete admixtures with good performaces can be obtained fxom alkali lignin after modifications such as oxidation, sulfonation, sulfomethylation and graft copolymerization.

  20. Brief talk about quality control of various aspects in pharmacy intravenous admixture service%浅谈 PIVAS 工作中各环节质量控制

    Institute of Scientific and Technical Information of China (English)

    石锐

    2015-01-01

    目的:通过分析总结静脉用药调配中心(PIVAS)各工作环节注意事项,为提高工作质量提供参考。方法:分析医嘱审核、摆药、配制等环节,提出针对性的解决措施。结果:加强医嘱审核、科学合理摆药、严密把握配制关等环节可进一步提高各环节质量。结论:通过各工作环节质量控制,为临床提供安全输液的静脉用药。%Objective:To summarize and analyze the points for attention of all work aspects in pharmacy intravenous ad-mixture service(PIVAS),to provide a reference for improve work quality. Methods:By analyzing prescriptions analysis,drug dispensing and admixture,to come up with purposeful solving measures. Results:By means of reinforcing prescription analysis, scientific and reasonable drug dispensing and strict drug admixture and so on,all aspects of work can be further improved. Con-clusion:According to the improvement measure of all work aspects,safe clinical infusion can be provided.