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201.
202.
Metzger Linda J.; Paige Stephen R.; Carson Margaret A.; Lasko Natasha B.; Paulus Lynn A.; Pitman Roger K.; Orr Scott P. 《Canadian Metallurgical Quarterly》2004,113(2):324
Researchers have proposed that depression and particular types of anxiety are associated with unique patterns of regional brain activation. The authors examined the relationship among posttraumatic stress disorder (PTSD), anxiety, and depressive symptoms and frontal, temporal, and parietal EEG alpha asymmetry in female Vietnam War nurse veterans. The results indicate that PTSD arousal symptoms are associated with increased right-sided parietal activation. However, the combination of arousal, depression, and their interaction explain more than twice the variance in parietal asymmetry compared with arousal alone. The results support the contention that the association between anxiety and right-sided posterior activation is specific to the anxious arousal subtype. These findings underscore the importance of isolating, both theoretically and statistically, emotional subcomponents in studies of regional brain activation. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
203.
Ewa Tocha Holger Schönherr G. Julius Vancso Natasha Siebelt 《Journal of the American Ceramic Society》2005,88(9):2498-2503
The nanotribological properties of nanostructured thin films of tetragonal ZrO2 on oxidized Si (100) were studied as a function of grain size and relative humidity (RH) by atomic force microscopy. The nanostructured ZrO2 showed a 50% decrease in friction coefficient μ compared with oxidized Si (100) in dry nitrogen atmosphere and 40% RH. A maximum of μ was observed at ca. 40% RH for both samples, while there were insignificant differences in μ for ZrO2 samples with grain sizes between 12 and 30 nm. The good tribological properties open the possibility for nanostructured zirconia to be applied as wear-resistant, low friction coatings on various materials. 相似文献
204.
Sorin Pirau Brandon Liberi Natasha Barbely Narayanan Komerath 《Journal of Mechanical Science and Technology》2016,30(9):3961-3967
Bluff bodies may assume arbitrary attitudes in a flow, causing aerodynamic loads that are sensitive to attitude. The Continuous rotation technique obtains 6-component loads on bluff bodies with 1-degree azimuth resolution about selected axes at a rate of 1 revolution per minute. The load coefficient variation is Fourier transformed and the resulting complex series is truncated in order to obtain rapidly computable, analytical formulae. The method is applied to bluff body shapes including cylinders, a cuboid, a flat plate and a porous box. A cylinder whose length is equal to its diameter, is used to show that rate effects, hysteresis, vortex shedding and other unsteady aerodynamic phenomena are negligible below 10 revolutions per minute. Approaches to generalize the aerodynamic loads on yawed finite cylinders of various aspect ratio are studied. The reasons for differences in aerodynamic load behavior between 2 cylinder models, are analyzed. To complement experiments, the ROTCFD unsteady Navier Stokes code is used to perform diagnostic computations. Methods to generalize the predictions are explored. Maps of the leading coefficients of the Fourier series of each load component over the aspect ratios space, are interpolated. The interpolation varies sharply for aspect ratios between 0.5 to 1. The variation is more gradual beyond aspect ratio 2. By aspect ratio 4, a ‘high aspect ratio’ limit appears to be reached. 相似文献
205.
The common brushtail possum (Trichosurus vulpecula) is a generalist herbivore whose diet includes Eucalyptus leaves that are well defended by plant secondary metabolites (PSM) such as the terpene 1,8-cineole (cineole). We accustomed
possums to a terpene-free diet, then challenged them with the addition of 2% cineole to the diet. Initially, there was a 50%
reduction in total overnight food consumption associated with a marked decrease in the mass of the major feeding bout. After
nine nights, however, cineole tolerance had developed as total food consumption had returned to the control amount. Compared
to the control diet, the cineole diet was eaten in a larger number of smaller bouts, which were also eaten at a slower rate.
The experiment was repeated with animals that had been accustomed to day-time feeding to take blood samples during feeding
sessions. Feeding variables and blood concentration data for cineole were compared on the first and seventh day of the cineole
diet. Although the total food consumed increased 2.5-fold after 7 days of the cineole diet, there was no increase in average
blood cineole concentration, measured as the area under the concentration–time curve. This indicates that induction of liver
enzymes resulted in greater pre-systemic metabolism of cineole and reduced bioavailability. The maximum tolerated blood concentration
of cineole also increased, suggesting some adaptation of the central nervous system to the cineole aversive effects. This
appears to be the first report in a vertebrate herbivore that consumption of a dietary PSM leads to metabolism induction and
that this contributes to development of tolerance to the PSM. Overall, herbivores adapt to newly encountered dietary PSMs
by immediate changes in feeding behavior followed by development of increased metabolism of PSM and probably diminished cellular
responsiveness to effects. 相似文献
206.
Cabrera Natasha J.; Ryan Rebecca M.; Mitchell Stephanie J.; Shannon Jacqueline D.; Tamis-LeMonda Catherine S. 《Canadian Metallurgical Quarterly》2008,22(4):643
Using data from a racially and ethnically diverse sample of low-income mothers of 2-year-old children participating in the Early Head Start Research and Evaluation Project (N = 883), the authors examined fathers' education and employment, mother-father relationship, and mothers' relationships with kin in the household to explain variation in nonresident father involvement across racial and ethnic groups. Nonresident White fathers were less involved with their children than were African American and Latino fathers. This difference was explained by the status of mother-father relationships. White nonresident fathers were less likely than minority nonresident fathers to maintain romantic relationships with their child's mother. Mothers in the White father group were also more likely to re-partner, which negatively related to biological fathers' involvement. These findings suggest that approaches to strengthen nonresident father involvement in children's lives need to consider how father ethnicity and mother-father relations are associated with differential patterns of father involvement. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
207.
Spencer Larkin Natasha Kyprianou 《International journal of molecular sciences》2013,14(9):18421-18436
Urologic tumors continue to represent a huge fraction of cancer cases in the United States, with over 376,310 estimated new diagnoses in 2013. As with many types of tumors, urologic tumors vary greatly in their phenotype, ranging from minimally invasive to malignancies possessing great metastatic potential. The increasing need for more efficient and less invasive methods of cancer detection, as well as the ability to predict severity of the disease phenotype is readily evident—yet reliable methods remain elusive in a clinical setting today. Comprehensive panels of gene clusters are being developed toward the generation of molecular signatures in order to better diagnose urologic malignancies, and identify effective treatment strategies in the emerging era of personalized medicine. In this review, we discuss the current literature on the credibility and biomarker value of such molecular signatures in the context of clinical significance relating to the pathological aggressiveness of urologic tumors (prostate, bladder and renal cancer)—also exploiting their predictive potential in the response to treatment. 相似文献
208.
It is pointed out by Jiang and Wang (2005) [1], that the conversion formula from Bernstein into DP bases is incorrect for all even degrees and the conversion formula from DP into Bernstein bases is incorrect for every degree. Thus, in this paper we give some notes, corrections and new proofs for the relationship between these two NTP bases. 相似文献
209.
A pentadentate salen-type ligand was immobilized in a poly[(styrene)]-co-(butyl acrylate)] matrix by miniemulsion polymerization. The obtained polymer beads revealed a particle size of 50 nm in the dry state by transmission electron microscopy. Dynamic light scattering experiments in methanol and water showed a solvent-dependent average particle size with a mean particle diameter of up to 233 nm in methanol. These results provide valuable insights for the optimization of macromolecular oxidation catalysts and their future use as enzyme-like entities in aqueous media. The particle stability was demonstrated over a wide pH range (3-11) by gel permeation chromatography, and initial results for the metal ion binding ability were obtained. 相似文献
210.
Nadler Natasha; Delgado Mauricio R.; Delamater Andrew R. 《Canadian Metallurgical Quarterly》2011,11(5):1112
Pavlovian learning tasks have been widely used as tools to understand basic cognitive and emotional processes in humans. The present studies investigated one particular task, Pavlovian-to-instrumental transfer (PIT), with human participants in an effort to examine potential cognitive and emotional effects of Pavlovian cues upon instrumentally trained performance. In two experiments, subjects first learned two separate instrumental response-outcome relationships (i.e., R1-O1 and R2-O2) and then were exposed to various stimulus-outcome relationships (i.e., S1-O1, S2-O2, S3-O3, and S4-) before the effects of the Pavlovian stimuli on instrumental responding were assessed during a non-reinforced test. In Experiment 1, instrumental responding was established using a positive-reinforcement procedure, whereas in Experiment 2, a quasi-avoidance learning task was used. In both cases, the Pavlovian stimuli exerted selective control over instrumental responding, whereby S1 and S2 selectively elevated the instrumental response with which it shared an outcome. In addition, in Experiment 2, S3 exerted a nonselective transfer of control effect, whereby both responses were elevated over baseline levels. These data identify two ways, one specific and one general, in which Pavlovian processes can exert control over instrumental responding in human learning paradigms, suggesting that this method may serve as a useful tool in the study of basic cognitive and emotional processes in human learning. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献