533 research outputs found

    Logarithmic entropy--corrected holographic dark energy with non--minimal kinetic coupling

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    In this paper, we have considered a cosmological model with the non--minimal kinetic coupling terms and investigated its cosmological implications with respect to the logarithmic entropy-- corrected holographic dark energy (LECHDE). The correspondence between LECHDE in flat FRW cosmology and the phantom dark energy model with the aim to interpret the current universe acceleration is also examined.Comment: 11 pages, 2 figures; Can. J. Phys. Vol. 90, 201

    Effects of Tillage and Rainfall on Atrazine Residue Levels in Soil

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    A field study was conducted in 1987 to 1991 to determine the effect of tillage and rainfall on distribution of atrazine in soil. Soil samples (10-cm increments to 50 cm) and crop residue samples were taken at regular intervals after application each year and analyzed for atrazine. Crop residue and living vegetation on no-till plots intercepted 60 to 70% of the applied atrazine; 3 to 16% of the atrazine remained in crop residue 1 to 2 wk later. The amount of atrazine recovered in soil, 1 to 2 wk post-treatment, ranged from 22 to 59 and 47 to 73% of the amount applied for no-till and conventional till, respectively. An average of 2.6 times more atrazine was recovered in the surface 10 cm of soil under conventional till than under no-till for all samplings and years. Total amounts of atrazine in the sampled profile (0- to 50-cm depth) were also generally lower under no-till than conventional till. More leaching below 10 cm occurred under no-till than conventional till, particularly in 1988 and 1990 when rain fell soon after application. Variation in soil atrazine levels among years was related to timing and amount of the first and subsequent rainfall after application

    Effects of Tillage and Rainfall on Atrazine Residue Levels in Soil

    Get PDF
    A field study was conducted in 1987 to 1991 to determine the effect of tillage and rainfall on distribution of atrazine in soil. Soil samples (10-cm increments to 50 cm) and crop residue samples were taken at regular intervals after application each year and analyzed for atrazine. Crop residue and living vegetation on no-till plots intercepted 60 to 70% of the applied atrazine; 3 to 16% of the atrazine remained in crop residue 1 to 2 wk later. The amount of atrazine recovered in soil, 1 to 2 wk post-treatment, ranged from 22 to 59 and 47 to 73% of the amount applied for no-till and conventional till, respectively. An average of 2.6 times more atrazine was recovered in the surface 10 cm of soil under conventional till than under no-till for all samplings and years. Total amounts of atrazine in the sampled profile (0- to 50-cm depth) were also generally lower under no-till than conventional till. More leaching below 10 cm occurred under no-till than conventional till, particularly in 1988 and 1990 when rain fell soon after application. Variation in soil atrazine levels among years was related to timing and amount of the first and subsequent rainfall after application

    Metrics for measuring distances in configuration spaces

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    In order to characterize molecular structures we introduce configurational fingerprint vectors which are counterparts of quantities used experimentally to identify structures. The Euclidean distance between the configurational fingerprint vectors satisfies the properties of a metric and can therefore safely be used to measure dissimilarities between configurations in the high dimensional configuration space. We show that these metrics correlate well with the RMSD between two configurations if this RMSD is obtained from a global minimization over all translations, rotations and permutations of atomic indices. We introduce a Monte Carlo approach to obtain this global minimum of the RMSD between configurations

    Associations Between Components of Metabolic Syndrome and Cognition in Patients With Schizophrenia

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    The metabolic syndrome and cognitive dysfunctions are common in patients with schizophrenia, yet there is no general consensus concerning the effects of the components of the metabolic syndrome on various cognitive domains. The goal of this study was to investigate the relationship between components of the metabolic syndrome and cognition in patients with schizophrenia. Components of the metabolic syndrome and neurocognitive functioning were assessed in 68 patients with schizophrenia. The Brief Assessment of Cognition in Schizophrenia (BACS) was used to assess neurocognition. Hyperglycemia and hypertension were the only components of the metabolic syndrome found to be associated with cognitive functioning. Patients with schizophrenia who were hypertensive showed cognitive impairments in 2 domains, with a negative association found between hypertension and verbal memory (P=0.047) and verbal fluency (P=0.007). Hyperglycemia was associated with higher scores on verbal memory (P=0.01) and verbal fluency (P<0.001). It appears that medical treatment of certain components of the metabolic syndrome could affect cognitive performance in patients with schizophrenia

    MoS2 Nanodonuts for High-Sensitivity Surface-Enhanced Raman Spectroscopy

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    Nanohybrids of graphene and two-dimensional (2D) layered transition metal dichalcogenides (TMD) nanostructures can provide a promising substrate for extraordinary surface-enhanced Raman spectroscopy (SERS) due to the combined electromagnetic enhancement on TMD nanostructures via localized surface plasmonic resonance (LSPR) and chemical enhancement on graphene. In these nanohybrid SERS substrates, the LSPR on TMD nanostructures is affected by the TMD morphology. Herein, we report the first successful growth of MoS2 nanodonuts (N-donuts) on graphene using a vapor transport process on graphene. Using Rhodamine 6G (R6G) as a probe, SERS spectra were compared on MoS2 N-donuts/graphene nanohybrids substrates. A remarkably high R6G SERS sensitivity up to 2 × 10−12 M has been obtained, which can be attributed to the more robust LSPR effect than in other TMD nanostructures such as nanodiscs as suggested by the finite-difference time-domain simulation. This result demonstrates that non-metallic TMD/graphene nanohybrids substrates can have SERS sensitivity up to one order of magnitude higher than that reported on the plasmonic metal nanostructures/2D materials SERS substrates, providing a promising scheme for high-sensitivity, low-cost applications for biosensing

    When Non-Suicidal Self-Injury Predicts Non-Suicidal Self-Injury and Poor Sleep—Results from a Larger Cross-Sectional and Quasi-Longitudinal Study

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    Poor sleep is associated with a higher risk of non-suicidal self-injury (NSSI) as a proxy of unfavorable emotion regulation. In the present study, we tested the hypothesis that past non-suicidal self-injury was associated with current non-suicidal self-injury and with current subjective sleep patterns. To this end, a larger sample of young adults were assessed. A total of 2374 adults (mean age: 27.58 years; 39.6% females) completed a series of self-rating questionnaires covering sociodemographic information, past and current NSSIs, suicide attempts, and current sleep patterns, including experiencing nightmares. Past NSSIs predicted current NSSIs. Current sleep patterns had a modest impact on the association between past and current NSSIs. Compared to male participants, female participants did not report more sleep complaints or more current NSSIs, but more past NSSIs. Past NSSIs predicted the occurrences of nightmares and suicide attempts. The best predictor of current NSSI was the remembered past NSSI, while current poor sleep was only modestly associated with current NSSI. Further indicators of current NSSI and poor sleep were suicide attempts and nightmares within the last six months. Overall, it appears that poor emotion regulation should be considered as underlying factor to trigger and maintain non-suicidal self-injury-related behavior and poor sleep. Further, unlike previous studies, which focused on the possible influence of sleep patterns on NSSIs, the aim of the present study paradigm was to investigate NSSIs on sleep patterns

    Numerical modeling of volumetric behavior of unsaturated expansive soil under wetting and drying cycles

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    peer reviewedExpansive soils undergo volumetric changes due to moisture variations as a result of soil-atmosphere interaction. In this study, the moisture-induced volumetric changes in unsaturated expansive soil under wetting-drying cycles were modeled. The variations in moisture content during wetting and drying cycles were analyzed for a specific type of expansive soil using one-dimensional coupled hydro-mechanical analysis within the framework of the Barcelona Expansive Model for expansive soils (BExM). The modeling was performed utilizing the finite element method in CODE_BRIGHT. The volume changes in the soil due to wetting and drying cycles, associated with changes in moisture and suction in the unsaturated zone, led to repetitive swelling and shrinkage deformations in the expansive soil. The effects of these variations were significantly more pronounced in the initial cycles, and after several cycles, the cyclic behavior within a specified range persisted for the same defined range of suction changes. However, this trend shifted towards more elastic behavior at lower rates of suction changes. Furthermore, the effect of surcharge on the volumetric behavior of swelling soil during wetting and drying cycles was investigated. As the surcharge increased, the magnitudes of cyclic deformation decreased. By comparing soil deformation under two different surcharge, elastic behavior was observed in the first three initial cycles for higher surcharge, followed by irreversible deformations. For lower surcharge, irreversible deformations were observed after the first cycle until equilibrium was reached after several wetting and drying cycles
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