267 research outputs found

    Proof Rolling of Foundation Soil and Prepared Subgrade During Construction

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    Proof rolling provides a method to examine the entire subgrade surface as a compliment to standard random acceptance testing. Proof rolling requires established criteria that account for the interplay of equipment parameters and soil characteristics, technique, and other specifics of the project to allow for proper interpretation. The researchers concluded that proof rolling is not appropriate for determining soil elastic properties, while it can reveal in situ strength properties. No information from state highway agencies (SHA) publications or interviews reports using proof rolling other than for the evaluation of the subgrade. Only eight SHA’s have notable specifications or other supporting documents containing significant guidance or criteria. The requirements provided for use of either of two equipment types—tandem-axle rear dump trucks and chariot-style rollers—and a range of evaluation criteria based on soil type and whether the project is new construction or re-construction. Recommendations provided fall within parameters practiced by states that have the most well-developed specifications and practices for proof rolling. The recommendations include: evaluation is of the subgrade only and the equipment shall be either a tandem-axle rear dump truck or a tri-axle rear dump truck (with raised third axle) loaded to a minimum gross weight of 20 tons. The chariot-style roller loaded to a minimum gross weight of 40 tons could be alternatively specified. The test shall be a single pass in each traffic lane with the passing criteria of a 1″ deflection for new construction and ½″ deflection for re-constructed or stabilized subgrade, as well as the absence of pumping and cracking

    Rational Prediction Of Future Pension Expense: A Simulation Approach

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    Because future pension expense can have a material influence on a firm’s future earnings, financial analysts are faced with the difficult task of forecasting its impact.  The purpose of this paper is to demonstrate a model that can be used with a simulation approach to predict future pension expense and its associated uncertainties.  Because of the importance and complexity of the pension expense component in the estimate of future earnings, a simulation model acts as a powerful analytical tool that can give the analyst greater confidence as to the magnitude and variability of future pension expense

    Catechol-O-methyltransferase Val158Met genotype in healthy and personality disorder individuals: Preliminary results from an examination of cognitive tests hypothetically differentially sensitive to dopamine functions

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    A functional polymorphism of the gene coding for Catechol-O-methyltrasferase (COMT), an enzyme responsible for the degradation of the catecholamine dopamine (DA), epinephrine, and norepinephrine, is associated with cognitive deficits. However, previous studies have not examined the effects of COMT on context processing, as measured by the AX-CPT, a task hypothesized to be maximally relevant to DA function. 32 individuals who were either healthy, with schizotypal personality disorder, or non-cluster A, personality disorder (OPD) were genotyped at the COMT Val158Met locus. Met/Met (n = 6), Val/Met (n = 10), Val/Val (n = 16) individuals were administered a neuropsychological battery, including the AX-CPT and the N-back working memory test. For the AX-CPT, Met/Met demonstrated more AY errors (reflecting good maintenance of context) than the other genotypes, who showed equivalent error rates. Val/Val demonstrated disproportionately greater deterioration with increased task difficulty from 0-back to 1-back working memory demands as compared to Met/Met, while Val/Met did not differ from either genotypes. No differences were found on processing speed or verbal working memory. Both context processing and working memory appear related to COMT genotype and the AX-CPT and N-back may be most sensitive to the effects of COMT variation

    Catechol-O-methyltransferase Val158Met genotype in healthy and personality disordered individuals: An examination of cognitive tests hypothetically differentially sensitive to dopamine functions

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    A functional polymorphism of the gene coding for Catechol-O-methyltrasferase (COMT), an enzyme responsible for the degradation of the catecholamine dopamine (DA), epinephrine, and norepinephrine, is associated with cognitive deficits. However, previous studies have not examined the effects of COMT on context processing, as measured by the AX-CPT, a task hypothesized to be maximally relevant to DA function. 32 individuals who were either healthy, with schizotypal personality disorder, or non-cluster A, personality disorder (OPD) were genotyped at the COMT Val158Met locus. Met/Met (n = 6), Val/Met (n = 10), Val/Val (n = 16) individuals were administered a neuropsychological battery, including the AX-CPT and the N-back working memory test. For the AX-CPT, Met/Met demonstrated more AY errors (reflecting good maintenance of context) than the other genotypes, who showed equivalent error rates. Val/Val demonstrated disproportionately greater deterioration with increased task difficulty from 0-back to 1-back working memory demands as compared to Met/Met, while Val/Met did not differ from either genotypes. No differences were found on processing speed or verbal working memory. Both context processing and working memory appear related to COMT genotype and the AX-CPT and N-back may be most sensitive to the effects of COMT variation

    Shoaling reduces metabolic rate in a gregarious coral reef fish species

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    Many animals live in groups because of the potential benefits associated with defense and foraging. Group living may also induce a 'calming effect' on individuals, reducing overall metabolic demand. This effect could occur by minimising the need for individual vigilance and reducing stress through social buffering. However, this effect has proved difficult to quantify. We examined the effect of shoaling on metabolism and body condition in the gregarious damselfish Chromis viridis. Using a novel respirometry methodology for social species, we found that the presence of shoal-mate visual and olfactory cues led to a reduction in the minimum metabolic rate of individuals. Fish held in isolation for 1 week also exhibited a reduction in body condition when compared with those held in shoals. These results indicate that social isolation as a result of environmental disturbance could have physiological consequences for gregarious species

    Connections: A Journal of Public Education Advocacy - Fall 2002, Vol. 9, No. 2

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    President's Message - Wendy D. Puriefoy sees education as the universal liberator and children as our nation's most valuable resource.Richard Riley on Transforming American Education - Don't shortchange adolescents, urges Richard W. Riley, Clinton administration secretary of education, as we build for a knowledge-driven economy.Q&A: Bob Moses - Civil rights activist Bob Moses promotes math literacy as the key to education and economic access.Making It Happen - Phyllis McClure, Title I expert, alerts parents and communities to valuable NCLB-mandated information on schools, districts, and states coming their way.Viewpoint - Boeing Company CEO Philip M. Condit links the need for a worldclass workforce to the need for quality public education.Conversations - Grassroots organizer Donna Cooper, Maryland lawmaker Pete Rawlings, and New York attorney Michael Rebell discuss accountability, adequacy, and fiscal equity as long-term investments in the future of our nation.End Notes - William Novelli, CEO, on how AARP members put lifelong learning into action

    Agenda-Setting With Local and National Issues

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    Three factors lead to the hypothesis that agenda-setting should be weaker at the local political level compared to the national level: (1) the more directly observable nature of local political problems, (2) the nature and strength of local interpersonal political communication networks, and (3) the relatively heavier media coverage of national political issues. This hypothesis was supported with data from respondents assigned at random to either local or national issue conditions and from a content analysis of television and newspaper coverage in Toledo, Ohio, of local and national issues. Contrary to the findings of certain previous studies, network television was found to exercise a stronger agenda-setting influence than newspapers at the national level. Newspapers, on the other hand, were the dominant agenda-setter at the local level. The relative agenda-setting influences of television versus newspapers are consistent with other data from this study concerning the relative strengths of the various media as sources of issue information.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67066/2/10.1177_009365027700400404.pd

    No Evidence of XMRV or MuLV Sequences in Prostate Cancer, Diffuse Large B-Cell Lymphoma, or the UK Blood Donor Population

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    Xenotropic murine leukaemia virus-related virus (XMRV) is a recently described retrovirus which has been claimed to infect humans and cause associated pathology. Initially identified in the US in patients with prostate cancer and subsequently in patients with chronic fatigue syndrome, doubt now exists that XMRV is a human pathogen. We studied the prevalence of genetic sequences of XMRV and related MuLV sequences in human prostate cancer, from B cell lymphoma patients and from UK blood donors. Nucleic acid was extracted from fresh prostate tissue biopsies, formalin-fixed paraffin-embedded (FFPE) prostate tissue and FFPE B-cell lymphoma. The presence of XMRV-specific LTR or MuLV generic gag-like sequences was investigated by nested PCR. To control for mouse DNA contamination, a PCR that detected intracisternal A-type particle (IAP) sequences was included. In addition, DNA and RNA were extracted from whole blood taken from UK blood donors and screened for XMRV sequences by real-time PCR. XMRV or MuLV-like sequences were not amplified from tissue samples. Occasionally MuLV gag and XMRV-LTR sequences were amplified from Indian prostate cancer samples, but were always detected in conjunction with contaminating murine genomic DNA. We found no evidence of XMRV or MuLV infection in the UK blood donors

    Integrated Colours of Milky Way Globular Clusters and Horizontal Branch Morphology

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    Broadband colours are often used as metallicity proxies in the study of extragalactic globular clusters. A common concern is the effect of variations in horizontal branch (HB) morphology--the second-parameter effect--on such colours. We have used UBVI, Washington, and DDO photometry for a compilation of over 80 Milky Way globular clusters to address this question. Our method is to fit linear relations between colour and [Fe/H], and study the correlations between the residuals about these fits and two quantitative measures of HB morphology. While there is a significant HB effect seen in U-B, for the commonly used colours B-V, V-I, and C-T_1, the deviations from the baseline colour-[Fe/H] relations are less strongly related to HB morphology. There may be weak signatures in B-V and C-T_1, but these are at the limit of observational uncertainties. The results may favour the use of B-I in studies of extragalactic globular clusters, especially when its high [Fe/H]-sensitivity is considered.Comment: 19 pages, including 26 figures. AN in press. Figure 9 stubbornly resists attempts to correct i
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