bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stress‐dependent hardening and failure surfaces of dry sand
Authors: Ehlers W. , Avci O. 
Published: January 2012

SUMMARYDuring several triaxial compression experiments on plastic hardening, softening, and failure properties of dense sand specimens, it was found on various stress paths that the size of the failure surface was not constant. Instead, it changed depending on the current state of hydrostatic pressure. This finding is in contrast to the standard opinion consisting of the fact that the failure surface remains constant, once it has been reached during an experiment or in situ.In general, the behaviour of cohesionless granular‐material‐like sand is somehow characterised in between fluid and solid, where the solid behaviour results from the angle of internal friction and the confining pressure. Although the friction angle is an intrinsic material property, the confining pressure varies with the boundary conditions, thus defining different solid properties like plastic hardening, softening, and also failure.Based on our findings, it was the goal of the present contribution to introduce an improved setting for the plastic strain hardening and softening behaviour including the newly found yield properties at the limit state. For the identification of the material parameters, a complete triaxial experimental analysis of the tested sand is given. The overall elasto‐plasticity concept is validated by numerical computations of several laboratory foundation‐ and slope‐failure experiments. The performance of the proposed approach is compared with the standard concept of a constant failure surface, where the corresponding yield surfaces are understood as contours of equivalent plastic work or plastic strain. Copyright © 2012 John Wiley & Sons, Ltd.
Household Members' Migration and the Education of Children ‘Left Behind’: Empirical Findings from Tajikistan and Reflections for Research Practice
Authors: Bennett Rachel , Clifford David , Falkingham Jane 
Published: January 2012

ABSTRACTThere is growing recognition that when a household member migrates, there is a complex range of social as well as economic consequences for the everyday lives of those who remain in the origin household. This paper examines the children left behind phenomenon in Tajikistan, a country with very high rates of international labour migration. With the use of data from the Tajikistan 2007 Living Standards Survey, logistic regression modelling is applied to examine the impact of fathers', mothers', siblings', and other household members' migration on the school enrolment of secondary school‐aged children. The results show that there is a significant positive association between longer‐term parental migration and children's enrolment, whereas the long‐term migration of siblings sending remittances and the mid‐term migration of ‘other household members’ (not parents or siblings) are both significantly negatively associated with children's enrolment. The findings highlight the importance of considering differences between children left behind. Copyright © 2012 John Wiley & Sons, Ltd.
Determination of CLA trans,trans Positional Isomerism in CLA‐Rich Soy Oil by GC–MS and Silver Ion HPLC
Authors: Shah Utkarsh , Proctor Andrew , Lay Jackson O. , Moon Kwangyul 
Published: January 2012

AbstractA ~20% CLA‐rich soy oil with low saturated fat and no cholesterol was produced by photoisomerizing soy oil linoleic acid. The oil is predominately trans,trans CLA, with the oil containing 17% trans,trans CLA. Recent studies have shown that trans,trans CLA‐rich soy oil significantly reduces heart disease and diabetes risk factors in obese rats. However, the positional isomerism of these geometrical isomers has not been identified. The objectives of the study were to determine trans,trans CLA positional isomerism of CLA fatty acids in CLA‐rich soy oil and determine the resolution of trans,trans CLA positional isomers by silver ion chromatography. GC–MS studies of 4‐phenyl‐1,2,4‐triazoline‐3,5‐dione (PTAD) derivatives of CLA‐rich oil showed that 9,11 CLA and 10,12 CLA were the major positional isomers. These were hypothesized to be the trans,trans CLA isomers, which was confirmed by silver ion chromatography and subsequent GC–FID fatty acid and ATR‐FTIR geometrical isomer analysis of the collected fractions. The identification of 9,11 trans,trans CLA and 10,12 trans,trans CLA as the major CLA isomers in CLA‐rich oil then allowed the deduction of the synthetic mechanism of the photoisomerism of soy oil linoleic acid to trans,trans CLA.
Diphenyl diselenide diet intake improves spatial learning and memory deficits in hypothyroid female rats
Authors: Dias Glaecir Roseni Mundstock , Vieira Francielli Araújo , Dobrachinski Fernando , Bridi Jéssika Cristina , Balk Rodrigo de Souza , Soares Félix Antunes , Nogueira Cristina Wayne , Barbosa Nilda Berenice de Vargas 
Published: January 2012

AbstractCognitive deficits have been observed in different animal models of adult‐onset hypothyroidism. Thus, this study was delineated to evaluate whether diphenyl diselenide, an organoselenium compound with neuroprotective and antioxidant properties, could afford protection against the detrimental effects of hypothyroidism on behavioral parameters. Hypothyroidism condition was induced in female rats by continuous exposure to methimazole (MTZ) at 20 mg/100 ml in the drinking water, during 3 months. MTZ‐induced hypothyroid rats were fed with either standard or a diet containing 5 ppm of diphenyl diselenide for 3 months. Behavioral assessments were performed monthly, in the following order: elevated plus maze, open field and Morris water maze. The levels of thyroid hormones in the animals exposed to MTZ were lower than control until the end of experimental period. The rats exposed to MTZ had a significant weight loss from the first month, which was not modified by diphenyl diselenide supplementation. In elevated plus maze test, MTZ exposure caused a reduction on the number of entries of animals in closed arms, which was avoided by diphenyl diselenide supplementation. In Morris water maze, the parameters latency to reach the platform and distance performed to find the escape platform in the test session were significantly greater in MTZ group when compared to control. These cognitive deficits observed in MTZ‐induced hypothyroid rats were restored by dietary diphenyl diselenide. The group fed with diphenyl diselenide alone exhibited a better spatial learning and memory capability in some parameters of Morris water maze when compared to the control group. In summary, our data provide evidence of the effectiveness of dietary diphenyl diselenide in improving the performance of control and hypothyroid rats in the water maze test.
Physical exercise reverses glutamate uptake and oxidative stress effects of chronic homocysteine administration in the rat
Authors: da Cunha Maira J. , da Cunha Aline A. , Ferreira Andréa G.K. , Machado Fernanda R. , Schmitz Felipe , Lima Daniela D. , Delwing Debora , Mussulini Ben Hur M. , Wofchuk Susana , Netto Carlos A. , Wyse Angela T.S. 
Published: January 2012

AbstractThe influence of physical exercise on the effects elicited by homocysteine on glutamate uptake and some parameters of oxidative stress, namely thiobarbituric acid‐reactive substances, 2′,7′‐dichlorofluorescein (H2DCF) oxidation, as well as enzymatic antioxidant activities, superoxide dismutase, catalase and glutathione peroxidase in rat cerebral cortex were investigated. Wistar rats received subcutaneous administration of homocysteine or saline (control) from the 6th to 29th day of life. The physical exercise was performed from the 30th to 60th day of life; 12 h after the last exercise session animals were sacrificed and the cerebral cortex was dissected out. It is shown that homocysteine reduces glutamate uptake increases thiobarbituric acid‐reactive substances and disrupts enzymatic antioxidant defenses in cerebral cortex. Physical activity reversed the homocysteine effects on glutamate uptake and on antioxidant enzymes activities; although the increase in thiobarbituric acid‐reactive substances was only partially reversed by exercise. These findings allow us to suggest that physical exercise may have a protective role against homocysteine‐induced oxidative imbalance and brain damage to the glutamatergic system.
Entrainment and mixing dynamics of surface-stress-driven stratified flow in a cylinder
Authors: Shravat A. , Cenedese C. , Caulfield C. P. 
Published: January 2012

AbstractWe extend previous work of Boyer, Davies & Guo (Fluid Dyn. Res., vol. 21, 1997, pp. 381–401) to consider the evolution of an initially two-layer stratified fluid in a cylindrical tank which is driven by a horizontal rotating disk. The turbulent motions induced by the disk drive entrainment at the interface, and similarly to the results of Boyeret al. (1997), the layer nearer to the disk deepens. Through high-frequency conductivity probe measurements, we establish that the deepening layer is very well-mixed, and the thickness of the interface between the two evolving layers appears to be approximately constant. Under certain circumstances, we find that the rate of increase in depth of the deepening layer decreases with time, at variance with the results of Boyeret al. (1997), and implying that the characteristic velocity in the deepening layer decreases as the upper layer deepens. We propose that such time-dependent deepening, and the associated weakening of the upper-layer velocities, occurs naturally because of the combined power requirements of entrainment and layer homogenization which inhibit, when the stratification is very strong, the characteristic velocities of the deepening layer approaching the (constant) velocities of the driving disk, as assumed by Boyeret al. (1997).
Experimental investigation of nonlinear instabilities in annular liquid sheets
Authors: Duke D. , Honnery D. , Soria J. 
Published: January 2012

AbstractThe aerodynamically driven annular liquid sheet exhibits a complex nonlinear instability. Novel interfacial velocimetry experiments suggest that two distinct physical sources of instability may be present. The first is the well-known free shear layer instability, which is quasi-sinusoidal and nonlinear. The second is a distinct nonlinear rupturing instability, modulated on the previous one. It may be directly driving primary atomization. This instability has not been previously observed in isolation and is inherently nonlinear and non-sinusoidal. Novel application of Koopman analysis and the Hilbert transform permit investigation of these distinct instabilities. A greater understanding of the rupturing instability may lead to a better understanding of atomization phenomena.
Strength of the relationships between three self-reported dietary intake instruments and serum carotenoids: the Observing Energy and Protein Nutrition (OPEN) Study
Authors: George Stephanie M , Thompson Frances E , Midthune Douglas , Subar Amy F , Berrigan David , Schatzkin Arthur , Potischman Nancy 
Published: January 2012

AbstractObjectiveTo assess the strength of the relationships between serum carotenoids and three self-reported dietary intake instruments often used to characterize carotenoid intake in studies of diet and disease.DesignParticipants completed a Diet History Questionnaire (DHQ), two 24 h dietary recalls (24HR), a fruit and vegetable screener and a fasting blood draw. We derived dietary intake estimates of α-carotene, β-carotene, cryptoxanthin, lutein, zeaxanthin and lycopene from each diet instrument and calculated sex-specific multivariate correlations between dietary intake estimates and their corresponding serum values.SettingMontgomery County, Maryland, USA.SubjectsFour hundred and seventy women and men aged 40–69 years in the National Cancer Institute's Observing Protein and Energy Nutrition (OPEN) Study.ResultsSerum carotenoids correlated more strongly with the DHQ (r = 0·34–0·54 for women; r = 0·38–0·56 for men) than with the average of two recalls (r = 0·26–0·47 for women; r = 0·26–0·40 for men) with the exception of zeaxanthin, for which the correlations using recalls were higher. With adjustment for within-person variation, correlations between serum carotenoids and recalls were greatly improved (r = 0·38–0·83 for women; r = 0·42–0·74 for men). In most cases, correlations between serum carotenoids and the fruit and vegetable screener resembled serum–DHQ correlations.ConclusionsEvidence from the study provides support for the use of the DHQ, a fruit and vegetable screener and deattenuated recalls for estimating carotenoid status in studies without serum measures, and draws attention to the importance of adjusting for intra-individual variability when using recalls to estimate carotenoid values.
If you stock it, will they buy it? Healthy food availability and customer purchasing behaviour within corner stores in Hartford, CT, USA
Authors: Martin Katie S , Havens Erin , Boyle Katie E , Matthews Gregory , Schilling Elizabeth A , Harel Ofer , Ferris Ann M 
Published: January 2012

AbstractObjectiveLiterature on food environments has expanded rapidly, yet most research focuses on stores and community characteristics without integrating customer-level data. The present study combines customer shopping behaviour with store food inventory data.DesignFace-to-face interviews were conducted with customers shopping in corner stores to measure food shopping behaviour, household food security and demographics. Store inventories were conducted to measure availability of healthy food in corner stores. Multilevel logistic regression models estimated the probability of customers purchasing a food item given the availability of that item in the store.SettingNineteen corner stores in Hartford, CT, USA, average size 669 ft2 (62·15 m2).SubjectsSample of 372 customers.ResultsThe majority of customers were Black or Hispanic (54 % and 40 %, respectively) and 61 % experienced food insecurity. For each additional type of fruits or vegetables available in the store, the estimated odds of a customer purchasing fruits increased by 12 % (P = 0·03) and the odds for purchasing vegetables increased by 15 % (P = 0·01). Customers receiving the Supplemental Nutrition Assistance Program (SNAP) were 1·7 times as likely to purchase fruit as those not receiving SNAP (P = 0·04). Greater availability of reduced-fat milk was not associated with increased likelihood of customers purchasing reduced-fat milk.ConclusionsThere is a positive association between fruit and vegetable variety and the probability that a customer purchases fruits and vegetables. Increasing the selection of produce in corner stores may increase their consumption by food-insecure and low-income residents at risk for health disparities. These findings have implications for future store interventions and food policies.
Conservation tillage issues: Cover crop-based organic rotational no-till grain production in the mid-Atlantic region, USA
Authors: Mirsky Steven B. , Ryan Matthew R. , Curran William S. , Teasdale John R. , Maul Jude , Spargo John T. , Moyer Jeff , Grantham Alison M. , Weber Donald , Way Thomas R. , Camargo Gustavo G. 
Published: January 2012

AbstractOrganic producers in the mid-Atlantic region of the USA are interested in reducing tillage, labor and time requirements for grain production. Cover crop-based, organic rotational no-till grain production is one approach to accomplish these goals. This approach is becoming more viable with advancements in a system for planting crops into cover crop residue flattened by a roller–crimper. However, inability to consistently control weeds, particularly perennial weeds, is a major constraint. Cover crop biomass can be increased by manipulating seeding rate, timing of planting and fertility to achieve levels (>8000 kg ha−1) necessary for suppressing summer annual weeds. However, while cover crops are multi-functional tools, when enhancing performance for a given function there are trade-off with other functions. While cover crop management is required for optimal system performance, integration into a crop rotation becomes a critical challenge to the overall success of the production system. Further, high levels of cover crop biomass can constrain crop establishment by reducing optimal seed placement, creating suitable habitat for seed- and seedling-feeding herbivores, and impeding placement of supplemental fertilizers. Multi-institutional and -disciplinary teams have been working in the mid-Atlantic region to address system constraints and management trade-off challenges. Here, we report on past and current research on cover crop-based organic rotational no-till grain production conducted in the mid-Atlantic region.
The importance of secondary trauma exposure for post-disaster mental disorder
Authors: Kessler R. C. , McLaughlin K. A. , Koenen K. C. , Petukhova M. , Hill E. D. ,   The WHO World Mental Health Survey Consortium
Published: January 2012

Background.Interventions to treat mental disorders after natural disasters are important both for humanitarian reasons and also for successful post-disaster physical reconstruction that depends on the psychological functioning of the affected population. A major difficulty in developing such interventions, however, is that large between-disaster variation exists in the prevalence of post-disaster mental disorders, making it difficult to estimate need for services in designing interventions without carrying out a post-disaster mental health needs assessment survey. One of the daunting methodological challenges in implementing such surveys is that secondary stressors unique to the disaster often need to be discovered to understand the magnitude, type, and population segments most affected by post-disaster mental disorders.Methods.This problem is examined in the current commentary by analyzing data from the WHO World Mental Health (WMH) Surveys. We analyze the extent to which people exposed to natural disasters throughout the world also experienced secondary stressors and the extent to which the mental disorders associated with disasters were more proximally due to these secondary stressors than to the disasters themselves.Results.Lifetime exposure to natural disasters was found to be high across countries (4.4–7.5%). 10.7–11.4% of those exposed to natural disasters reported the occurrence of other related stressors (e.g. death of a loved one and destruction of property). A monotonic relationship was found between the number of additional stressors and the subsequent onset of mental disordersConclusions.These results document the importance of secondary stressors in accounting for the effects of natural disasters on mental disorders. Implications for intervention planning are discussed.
CALIOP observations of the transport of ash from the Eyjafjallajökull volcano in April 2010
Authors: Winker D. M. , Liu Z. , Omar A. , Tackett J. , Fairlie D. 
Published: January 2012

The Cloud‐Aerosol Lidar with Orthogonal Polarization (CALIOP) is an elastic backscatter lidar carried on the CALIPSO satellite. CALIOP observations between 15 and 20 April 2010 of volcanic ash plumes following the eruption of the Icelandic Eyjafjallajökull volcano are reported here. While CALIOP has limited spatial coverage due to nadir‐only sampling, ash plumes were observed by CALIOP over a wide region ‐ from the North Atlantic Ocean to eastern Europe ‐ during both day and night. Due to its nadir‐only view, however, CALIOP did not sample the densest ash plumes which were observed by passive satellite sensors and ground‐based lidar. Lidar depolarization and spectral backscatter signatures are used to discriminate ash layers from clouds. Most ash was observed in thin layers of laminar appearance with thicknesses ranging from 0.4 km to a little more than 1 km and at relatively low altitudes, between 1 and 7 km. Most layers reported here produced strong lidar depolarization, indicating a predominance of ash over sulfate aerosol in the plumes. Estimates of lidar extinction‐to‐backscatter ratio allow the retrieval of profiles of ash optical properties. Layers were observed with mean optical extinction ranging from 0.03 km−1 to nearly 1 km−1. Combined with an estimate of mass extinction efficiency, mass concentration profiles can also be estimated. These observations of the three‐dimensional dispersion of the plume are complementary to observations from passive satellite instruments and ground‐based lidars, and can be useful for verification of dispersion models such as those used by the Volcanic Ash Advisory Centers.
Delayed formation of the equatorial ridge on Iapetus from a subsatellite created in a giant impact
Authors: Dombard Andrew J. , Cheng Andrew F. , McKinnon William B. , Kay Jonathan P. 
Published: January 2012

The great equatorial ridge on Saturn's moon Iapetus is arguably the most perplexing landform in the solar system. The ridge is a mountain range up to 20 km tall and sitting on the equator of Iapetus, and explaining its creation is an unresolved challenge. Models of its formation must satisfy three critical observations: why the ridge (1) sits exactly on the equator, (2) is found only on the equator, and (3) is thus far found only on Iapetus. We argue that all previously proposed models fail to satisfy these observations, and we expand upon our previous proposal that the ridge ultimately formed from an ancient giant impact that produced a subsatellite around Iapetus. The orbit of this subsatellite would then decay, once Iapetus itself had despun due to tides raised by Saturn, until tidal forces from Iapetus tore the subsatellite apart. The resultant debris formed a transient ring around Iapetus, the material of which rained down on the surface to build the ridge. By sequestering the material in a subsatellite with a tidally evolving orbit, formation of the ridge is delayed, which increases the likelihood of preservation against the high‐impact flux early in the solar system's history and allows the ridge to form on thick, stiff lithosphere (heat flow likely <1 mW m−2) required to support this massive load without apparent flexure. This mechanism thus explains the three critical observations.
Isoglitter
Authors: Bucknum Michael , Castro Eduardo , Wen Bin 
Published: January 2012

AbstractDescribed herein is a novel crystalline pattern in space group Ammm, that is a model of a C allotrope. This so-called isoglitter structure-type is an analogue to the graphite-diamond hybrids. A DFT geometry optimization and band structure calculation indicates that the lattice is metallic in a C realization.
Enhancement in Informational Masking
Authors: Cao Xiang , Richards Virginia M. 
Published: January 2012

Purpose
The ability to detect a tone added to a random masker improves when a preview of the masker is provided. In 2 experiments, the authors explored the role that perceptual organization plays in this release from masking.

Method

Detection thresholds were measured in informational masking studies. The maskers were drawn at random prior to each trial. Masker or signal-plus-masker precursors preceded the detection interval, and the time between the precursor and the detection interval was systematically altered. In
Experiment 1
, the signal frequency was either fixed or random. In
Experiment 2
, the random masker was composed of harmonics of a common fundamental frequency (F
0
), and the randomly chosen signal frequency was either harmonically related to, or mistuned from, the masker’s F
0
.

Results

For a masker precursor, the release from informational masking withstood longer precursor-detection interval delays (a) when the signal frequency was fixed versus random and (b) when the signal was mistuned relative to a harmonic of the masker’s F
0
.

Conclusion
These results suggest that listeners' ability to attend to the signal may contribute to the long-lived release from masking with a masker precursor.