1,939 research outputs found

    Levelling aeromagnetic survey data without the need for tie-lines

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    A new methodology that levels airborne magnetic data without orthogonal tie-lines is presented in this study. The technique utilizes the low-wavenumber content of the flight-line data to construct a smooth representation of the regional field at a scale appropriate to the line lengths of the survey. Levelling errors are then calculated between the raw flight-line data and the derived regional field through a least squares approach. Minimizing the magnitude of the error, with a first-degree error function, results in significant improvements to the unlevelled data. The technique is tested and demonstrated using three recent airborne surveys

    Identification of T-cell receptor a-chain genes in the chicken

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    T-cell receptor (TCR) -chain (TCR) and ß-chain (TCRß) genes are well characterized in mammals, while only TCRß genes have been identified in other vertebrates. To identify avian TCR genes, we used monoclonal anti-CD3 antibodies to isolate chicken TCR for peptide sequence analysis. Degenerate oligonucleotide probes were then used to isolate a candidate TCR cDNA clone that hybridized with a 1.7-kb mRNA species present only in ß T cells and in tissues populated by these cells. Southern blot analysis revealed gene rearrangement in thymocytes and ß T-cell lines. The TCR cDNA candidate encoded an openreading frame of 275 amino acids, the predicted variable (V)-, joining (J)-, and constant (C)-region amino acid sequences of which shared 40%, 60%, and 25% homology with corresponding mammalian sequences. A single C gene and 25 V genes were identified by using region-specific probes. The V cDNA probe isolated from a Vß1+ cell line reacted with transcripts from one of five Vß2+ cell lines, suggesting shared use of V genes by Vß1+ and Vß2+ T cells and the existence of other V gene families. A genomic V sequence was flanked by classical recombination signal sequences but, unlike previously defined V genes, the leader and V region were encoded by a single exon. The data indicate evolutionary conservation of the basic TCR gene structure in birds and mammal

    At-risk and problem gambling among adolescents : a convenience sample of first-year junior high school students in Finland

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    Background: Adolescent gambling and substance use are viewed as a public health concern internationally. The early onset age of gambling is a known risk factor for developing gambling problems later in life. The aims of this study are: to evaluate the internal consistency reliability, factorial validity and classification accuracy of the Finnish version of DSM-IV-Multiple Response-Juvenile (DSM-IV-MR-J) criteria measuring at-risk/problem gambling (ARPG); to examine gender differences in gambling participation, ARPG and substance use among first-year junior high school students; and to investigate the association of gambling and gaming (video game playing) participation, substance use and social variables with ARPG. Methods: This study examined 988 adolescents (mean age 13.4 years) at 11 public schools in Finland between October-December 2013. The response rate was 91.6%. Chi-squared test and binary logistic regression analysis were used. Results: 'Illegal acts' was the most endorsed and sensitive, but the least specific criteria identifying ARPG. During the past year, 51.6% of the respondents had gambled, 7.9% were identified as at-risk/problem gamblers (DSM-IV-MR-J score >= 2), 8.0% had smoked and 8.9% had been drinking for intoxication, and the first three were significantly more common among boys than girls. The odds ratio of being a male past-year at-risk/problem gambler was 2.27, 5.78 for gambling often or sometimes, 2.42 for video game playing weekly or more often and 6.23 for having peer gamblers. Conclusions: Overall, the Finnish version of the DSM-IV-MR-J had acceptable internal consistency reliability and factorial validity. None of the DSM-IV-MR-J criteria were accurate enough to screen ARPG per se. ARPG past-year prevalence was relatively high with males gambling more than females. ARPG was as common as drinking alcohol for intoxication and smoking. Peer gambling was strongly associated with ARPG. Efficient strategies to minimise the risks of gambling problems, tools for prevention and identification of ARPG among the underage are needed.Peer reviewe

    Measurement uncertainty relations

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    Measurement uncertainty relations are quantitative bounds on the errors in an approximate joint measurement of two observables. They can be seen as a generalization of the error/disturbance tradeoff first discussed heuristically by Heisenberg. Here we prove such relations for the case of two canonically conjugate observables like position and momentum, and establish a close connection with the more familiar preparation uncertainty relations constraining the sharpness of the distributions of the two observables in the same state. Both sets of relations are generalized to means of order α\alpha rather than the usual quadratic means, and we show that the optimal constants are the same for preparation and for measurement uncertainty. The constants are determined numerically and compared with some bounds in the literature. In both cases the near-saturation of the inequalities entails that the state (resp. observable) is uniformly close to a minimizing one.Comment: This version 2 contains minor corrections and reformulation

    The Tellus Airborne Geophysical Survey of Northern Ireland. Final results

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    The Tellus airborne geophysical survey of Northern Ireland was conducted over a two year period. Measurements from a fixed-wing aircraft operating at 56 m include magnetic (gradiometer), radiometric and frequency-domain electromagnetic. The survey comprises over 80,000 line-km of coverage and was completed in two phases (2005 and 2006). The large geographical scale and two year duration have combined to raise interesting questions regarding data processing and seasonal adjustments. The radiometric and electromagnetic data sets are completely new for N.Ireland, whereas the magnetic data set is significantly better than the existing one. The preliminary results have excited the interest of the planning, mineral and environmental communities

    Treatment of alcohol dependence in patients with co-morbid major depressive disorder – predictors for the outcomes with memantine and escitalopram medication

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    <p>Abstract</p> <p>Background</p> <p>Alcohol dependence comorbid with major depressive disorder poses a major challenge in the clinical setting. The results in the treatment with selective serotonin re-uptake inhibitors have been conflicting. Thus, we compared in alcohol-dependent patients with co-morbid major depressive disorder the selective serotonin re-uptake inhibitor escitalopram to a compound that acts on different transporter system and may reduce craving, the glutamate receptor antagonist memantine.</p> <p>Methods</p> <p>Eighty alcohol-dependent patients comorbid with major depressive disorder in municipal alcohol clinics were randomized 1:1 to receive memantine 20 mg or escitalopram 20 mg in a double-blind manner. During the 26-week study period patients continued their routine treatment at the clinics. Abstinence was not required but encouraged. The patients attended visits weekly during the first month, and then at 3 and at 6 months. Outcome measures were Alcohol Use Disorders Identification Test (AUDIT), Obsessive Compulsive Drinking Scale (OCDS) and Drinking Diary.</p> <p>Results</p> <p>The completion rate was high in both groups, especially among the patients who had been abstinent at the beginning of the study. However, among those patients who were not abstinent at baseline, 47% in both groups discontinued the study. Numbers of abstinent days were high in both groups throughout the study. Alcohol consumption measured by the AUDIT QF (quantity-frequency) score was significantly reduced in both groups, as was the craving for alcohol measured by the OCDS. Early age at first alcohol intoxication predicted poor treatment outcomes in patients treated with escitalopram, and the same was seen with the early onset of the first depressive episode. The same predictive effects were not found in patients treated with memantine.</p> <p>Conclusion</p> <p>Our results indicate that both memantine and escitalopram are useful adjunct medications for the treatment of alcohol dependence co-morbid with major depression. Memantine was at least as effective with regard to drinking as escitalopram. We believe that a direct comparison of memantine, with the commonly used escitalopram, can provide useful information for clinicians on the treatment of alcohol dependency co-morbid with MDD.</p> <p>Trial registration</p> <p>ClinicalTrials.gov Identifier # NCT00368862</p

    Coverage-dependent structural phase transformations in the adsorption of pentacene on an aperiodically modulated Cu film

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    Surface ordering of pentacene molecules adsorbed on an aperiodic Cu surface has been studied with density functional theory (DFT) and scanning tunnelling microscopy as a function of coverage. Below 0.73 ML (5.3 × 1013 molecules cm−2), the adsorbate structure is row-like with the molecular axes aligned with the rows in the Cu structure. Between this coverage and 1 ML (7.3 × 1013 molecules cm−2), a structural phase with a checkerboard structure is seen. At this coverage region, the molecules are very close to each other which leads to unusual bending. At higher coverages, a further phase transition to a high-density row structure is seen for most of the film. DFT with van der Waals functionals is employed to study how the molecule-molecule and molecule-surface interactions evolve as a function of coverage
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