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11.
Negative binomial regression models were used to assess the effect of street and street network characteristics on total crashes, severe injury crashes, and fatal crashes. Data from over 230,000 crashes taking place over 11 years in 24 California cities was analyzed at the U.S. Census Block Group level of geography. In our analysis we controlled for variables such as vehicle volumes, income levels, and proximity to limited access highways and to the downtown area. Street network characteristics that were considered in the analysis included street network density and street connectivity along with street network pattern.Our findings suggest that for all levels of crash severity, street network characteristics correlate with road safety outcomes. Denser street networks with higher intersection counts per area are associated with fewer crashes across all severity levels. Conversely, increased street connectivity as well as additional travel lanes along the major streets correlated with more crashes. Our results suggest that in assessing safety, it is important to move beyond the traditional approach of just looking at the characteristics of the street itself and examine how the interrelated factors of street network characteristics, patterns, and individual street designs interact to affect crash frequency and severity. 相似文献
12.
B.John Garrick 《Reliability Engineering & System Safety》1998,59(1):41-45
Technological stigmas can be a source of confusion and misunderstandings of the effect on public health and safety of technological activities. The result can be a gross waste of national resources to fix the ‘stigma’ rather than the real problem. Fueling technological stigmas has become a visible activity, especially among non-technical professionals. Further, it is not clear that these same critics are accountable for their influence on policy and practices that may adversely affect people's lives and financial resources. Their bad news of alleged high risk and incompetent technologists is more appealing to the press than the more technical and apparently boring news of finding engineering solutions to real problems.The issue of technological stigma is especially visible in relation to the environmental and safety effects of the nuclear and chemical industries. These industries are in an extremely defensive position because the stigmatizes put much more emphasis on their risks than on their benefits to society. There is the genuine threat of the denial of important technologies in the nuclear and chemical fields and a resulting loss of lives and resources. The actions required to better tell the whole cost-risk-benefit story of specific technologies have to come from all of the groups involved. The critics and stigmatizers need to be more accountable for their assertions, the technologists need to involve the public more in their consideration of technological solutions to environmental and safety issues, and the press needs to present all of the facts rather than just the sensational or ‘outrage’ part of the story. 相似文献
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Protective systems for nuclear power reactors have assumed a high degree of development. The primary motive has been the emphasis given to making reactors safe and more recently the desire to offset the site distance requirement through engineered safeguards. Increased reactor operating experience and improved safety analyses have contributed to a better definition of the events and conditions requiring protective systems. The judicious use of such philosophies as redundancy and coincidence in system designs has led to both greater safety and reactor operating continuity. Reliability of protective systems has been enhanced by parallel efforts in system and individual component design. Techniques and procedures for checking and testing protective systems have been developed and adopted at many installations to offset the inherent difficulty of assessing reliability of systems which experience little or no use under actual stressed conditions. Design practices have been effected to provide greater assurance that systems are independent although this remains as one of the outstanding problems. Protective systems in the context of monitoring devices are being developed by the application of noise analyses, digital computer control and the use of transistorized or solid state circuitry. Finally, the actual performance of protective systems is being manifested through analysis of existing operating records. 相似文献
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The diffusional permeability coefficients, PD, for tritiated water (3HHO) 14C-antipyrine (AP) and 14C-iodoantipyrine (IAP) in isolated calf pulmonary artery endothelial cells and dog erythrocytes are measured with the linear diffusion technique at 11.5, 15, 20 and 37 degrees C. The PD values for both cell populations follow the sequence 3HHO > IAP > AP at each of the temperatures. PD for water is higher in the erythrocyte compared to the endothelial cells. The differences in PD for AP and IAP in the erythrocytes and endothelial cells are not dramatic and are similar to the differences seen in comparing permeation of the same solute through bilayers of different composition. A comparison of the values of PD calculated for the endothelial cells with those for isolated capillaries and the structured endothelium in whole lungs validates the use of the isolated cells as models for the endothelial cells in situ. Incubation of the endothelial cells with cis-vaccenic acid or cholesterol produces a reduction in PD for water and antipyrine. These data are analyzed in terms of Stokesian and non-Stokesian diffusion. The interpretation which best accommodates the data is that the phospholipid area of the membrane, rather than the hydrocarbon core, provides the greatest resistance to permeation for these solutes. 相似文献
17.
G. Apostolakis S. Kaplan B.J. Garrick R.J. Duphily 《Nuclear Engineering and Design》1980,56(2):321-329
Bayes' theorem is used to derive plant specific distributions for the failure rates of components. Methods are suggested for the derivation of generic distributions from information that appears in the literature. These distributions are used as prior distributions in Bayes' theorem and they are modified using plant specific data. The posterior distributions thus derived can be used as inputs in a plant specific risk analysis. 相似文献
18.
G. Baskar A. Gurugulladevi T. Nishanthini Bikku George Garrick R. Aiswarya M. Gopinath 《Journal of Inorganic and Organometallic Polymers and Materials》2016,26(4):876-880
Bioactive peptides from Ixora coccinea Linn flowers have been reported to have anticancer activity against various cancer cells. Zinc oxide nanoparticle is the promising metal nanoparticle for anticancer applications. In the present work, ZnO was synthesized using I. coccinea Linn flower extract. The synthesized ZnO nanoparticle was found as phytonanocomposite of ZnO nanoparticle and bioactive components. The synthesized ZnO phytonanocomposite was confirmed using UV Spectroscopic analysis with maximum wavelength at 357.6 nm. The presence of bioactive peptides in the nanophytocomposite was confirmed using FT-IR analysis with strong peaks at 3402 and 1629 cm?1. The particle size and surface characteristics of bioactive phytonanocomposite of ZnO was studied using Scanning Electron Microscope. The anticancer activity of zinc oxide nanocomposite of I. coccinea Linn flower extract was found to be efficient on MCF-7 cell line. 相似文献
19.
Gerson A. Oliveira Júnior Tatiane C.S. Chud Ricardo V. Ventura Dorian J. Garrick John B. Cole Danísio P. Munari José B.S. Ferraz Erik Mullart Sue DeNise Shannon Smith Marcos Vinícius G.B. da Silva 《Journal of dairy science》2017,100(12):9623-9634
The objective of this study was to investigate different strategies for genotype imputation in a population of crossbred Girolando (Gyr × Holstein) dairy cattle. The data set consisted of 478 Girolando, 583 Gyr, and 1,198 Holstein sires genotyped at high density with the Illumina BovineHD (Illumina, San Diego, CA) panel, which includes ~777K markers. The accuracy of imputation from low (20K) and medium densities (50K and 70K) to the HD panel density and from low to 50K density were investigated. Seven scenarios using different reference populations (RPop) considering Girolando, Gyr, and Holstein breeds separately or combinations of animals of these breeds were tested for imputing genotypes of 166 randomly chosen Girolando animals. The population genotype imputation were performed using FImpute. Imputation accuracy was measured as the correlation between observed and imputed genotypes (CORR) and also as the proportion of genotypes that were imputed correctly (CR). This is the first paper on imputation accuracy in a Girolando population. The sample-specific imputation accuracies ranged from 0.38 to 0.97 (CORR) and from 0.49 to 0.96 (CR) imputing from low and medium densities to HD, and 0.41 to 0.95 (CORR) and from 0.50 to 0.94 (CR) for imputation from 20K to 50K. The CORRanim exceeded 0.96 (for 50K and 70K panels) when only Girolando animals were included in RPop (S1). We found smaller CORRanim when Gyr (S2) was used instead of Holstein (S3) as RPop. The same behavior was observed between S4 (Gyr + Girolando) and S5 (Holstein + Girolando) because the target animals were more related to the Holstein population than to the Gyr population. The highest imputation accuracies were observed for scenarios including Girolando animals in the reference population, whereas using only Gyr animals resulted in low imputation accuracies, suggesting that the haplotypes segregating in the Girolando population had a greater effect on accuracy than the purebred haplotypes. All chromosomes had similar imputation accuracies (CORRsnp) within each scenario. Crossbred animals (Girolando) must be included in the reference population to provide the best imputation accuracies. 相似文献
20.
Physiology deals with the functions of living organisms and their systems, and its scientific endeavors can be viewed as having temporally occurred in 3 phases. The first phase of physiology studies focused on determining the functions of particular organs and tissues and their functional differences according to physiological status. The second phase of studies focused on characterizing differences in these functions according to the environment, or productivity. The third phase of studies focuses on determining the physiological causes of differences in productivity. Distinguishing cause from effect in physiological systems of inter-related processes is problematic, such that science has struggled to identify the root physiological mechanisms and their role in the network of genes leading to differences in productivity. Genomics is the study of the entire genome and provides powerful new tools that will accelerate third-phase discoveries of causal physiological processes. That research exploits information on DNA polymorphisms known as markers, complete DNA sequence, RNA sequence, and RNA expression in particular tissues at specific life stages. Physiologists can determine the genetic cause of mutant animals, identify genetic differences between cases and controls, and identify genes responsible for differences in performance between average and above-average animals. In some species, physiologists can leverage genomic data being used to predict genetic merit in elite seedstock populations, as a starting point to identify genes that will then motivate detailed physiological studies in the organs or tissues and stages of life in which those genes are expressed. Such work will increase our knowledge of biology and may lead to novel approaches to manipulate animal performance. 相似文献