78 research outputs found

    Report of the panel on plate motion and deformation, section 2

    Get PDF
    Given here is a panel report on the goals and objectives, requirements and recommendations for the investigation of plate motion and deformation. The goals are to refine our knowledge of plate motions, study regional and local deformation, and contribute to the solution of important societal problems. The requirements include basic space-positioning measurements, the use of global and regional data sets obtained with space-based techniques, topographic and geoid data to help characterize the internal processes that shape the planet, gravity data to study the density structure at depth and help determine the driving mechanisms for plate tectonics, and satellite images to map lithology, structure and morphology. The most important recommendation of the panel is for the implementation of a world-wide space-geodetic fiducial network to provide a systematic and uniform measure of global strain

    Effects of Bedrock Lithology and Subglacial Till on the Motion of Ruth Glacier, Alaska, Deduced from Five Pulses from 1973-2012

    Get PDF
    A pulse is a type of unstable glacier flow intermediate between normal flow and surging. Using Landsat MSS, TM, and ETM+ imagery and feature tracking software, a time-series of mostly annual velocity maps from 1973 to 2012 was produced that reveals five pulses of Ruth Glacier, Alaska. Peaks in ice velocity were found in the 1981, 1989, 1997, 2003, and 2010; approximately every 7 years. During these peak years the ice velocity increased 300%, from approximately 40 m/yr to 160 m/yr, and occurred in an area of the glacier underlain by sedimentary bedrock. Based on the spatio-temporal behavior of Ruth Glacier during the pulse cycles, we suggest the pulses are due to enhanced basal motion via deformation of a subglacial till. The cyclical nature of the pulses is theorized to be due to a thin till, with low permeability, that causes incomplete drainage of the till between the pulses, followed by eventual recharge and dilation of the till. These findings suggest care is needed when attempting to correlate changes in regional climate with decadal-scale changes in velocity, because in some instances basal conditions may have a greater influence on ice dynamics than climate

    Degradation of haloaromatic compounds

    Get PDF
    An ever increasing number of halogenated organic compounds has been produced by industry in the last few decades. These compounds are employed as biocides, for synthetic polymers, as solvents, and as synthetic intermediates. Production figures are often incomplete, and total production has frequently to be extrapolated from estimates for individual countries. Compounds of this type as a rule are highly persistent against biodegradation and belong, as "recalcitrant" chemicals, to the class of so-called xenobiotics. This term is used to characterise chemical substances which have no or limited structural analogy to natural compounds for which degradation pathways have evolved over billions of years. Xenobiotics frequently have some common features. e.g. high octanol/water partitioning coefficients and low water solubility which makes for a high accumulation ratio in the biosphere (bioaccumulation potential). Recalcitrant compounds therefore are found accumulated in mammals, especially in fat tissue, animal milk supplies and also in human milk. Highly sophisticated analytical techniques have been developed for the detection of organochlorines at the trace and ultratrace level

    Exploring substance use and impaired driving among adults aged 21 years and older in the United States, 2015

    No full text
    <p><b>Introduction:</b> Alcohol- or drug-impaired driving can cause motor vehicle crashes, injuries, and death. Estimates of drug-impaired driving are difficult to obtain. This study explores self-reported prevalence of and factors associated with alcohol, marijuana, and prescription opioid use and impaired driving among adults aged 21 years and older in the United States.</p> <p><b>Methods:</b> Self-reported data from 3,383 adults in the 2015 Fall ConsumerStyles survey were analyzed. Respondents were asked about alcohol, marijuana, and prescription opioid use and driving while impaired in the last 30 days. Weighted prevalence estimates were calculated. Prevalence ratios and Poisson log-linear regressions were used to identify factors associated with substance use and impaired driving.</p> <p><b>Results:</b> Alcohol use was reported by 49.5% (<i>n</i> = 1,676) of respondents; of these, 4.9% (<i>n</i> = 82) reported alcohol-impaired driving. Marijuana use was reported by 5.5% (<i>n</i> = 187) of respondents; of these, 31.6% (<i>n</i> = 59) reported marijuana-impaired driving. Prescription opioid use was reported by 8.8% (<i>n</i> = 298) of respondents; of these, 3.4% (<i>n</i> = 10) reported prescription opioid–impaired driving. Polysubstance use of alcohol and marijuana (concurrent use) was reported by 2.7% (<i>n</i> = 93) of respondents. Among those, 10.8% (<i>n</i> = 10) reported driving impaired by both alcohol and marijuana.</p> <p><b>Conclusions:</b> Impaired driving was self-reported among alcohol, marijuana, and prescription opioid users. This article demonstrates the need for more robust alcohol- and drug-related data collection, reporting, and analyses, as well as the emerging need for surveillance of marijuana and prescription opioid–impaired driving. States can consider using proven strategies to prevent impaired driving and evaluate promising practices.</p

    The Association Between County-Level Injury Rates and Racial Segregation Revisited: A Multilevel Analysis

    No full text
    Objectives. We investigated whether within-county racial segregation was associated with increased odds of violent injury beyond individual risk

    Gene differentiation among ten endogamous groups of West Bengal, India

    No full text
    Ten endogamous populations of West Bengal, India have been surveyed for genetic variation in 12 systems. These populations encompass all social ranks in the caste hierarchy and cover almost the entire geographic area of the state. Gene diversity analysis suggests that these groups exhibit significant allele frequency variation at all but three loci. The overall genetic difference is not, however, in accord with the classification based on caste. Two low-ranking scheduled caste groups are, in fact, in close proximity with the high-caste ones, suggesting evidence of past generations of gene flow among them. Three different clusters of groups emerge from the present data, providing support for the anthropologic assertion that in Bengal Proto-Australoid, Caucasoid, and Mongoloid racial elements generally coexist. However, these three components are not uniformly present in all groups. Geographic separation of the groups is a strong determinant of the gene differentiation that exists among these populations

    Immunoglobulin (Gm and Km) allotypes in nine endogamous groups of West Bengal, India

    No full text
    Blood samples from 898 individuals of nine endogamous groups of West Bengal, India were typed for determining the haplotypic structure in the x-light chain (Gm) and x-light chain (Km) of immunoglobulin (IgG). The Gm haplotype frequencies detected by Glm (1), Glm (2) and G3m (5) markers suggest that in this eastern state of India there is considerable variation of frequencies of the typical Mongoloid haplotype Gm, which shows a high incidence in Rajbanshi, Rabha, Garo and Lodha groups. On the contrary, this haplotype is probably absent in the high caste groups, Rarhi Brahmin and Vaidya, and is relatively infrequent in Jalia Kaibarta, a scheduled caste of the south-western part of the state. The Km allele is also high in frequency among Rajbanshi, Rabha, Garo and Munda in comparison with Rarhi Brahmin and Vaidya, suggesting the former four groups' strong Mongoloid affiliation. This survey signifies that there is considerable variation in the extent of Mongoloid admixture in Bengali populations. Such admixture is not restricted in specific social class either. It further demonstrates that heterogeneity of the genetic structure of Bengali populations do not correspond to the present social ranking on the basis of caste hierarchy
    • …
    corecore