Sex differences in HIV effects on visual memory among substance-dependent individuals.

PubMed

Keutmann, Michael K; Gonzalez, Raul; Maki, Pauline M; Rubin, Leah H; Vassileva, Jasmin; Martin, Eileen M

2017-08-01

HIV's effects on episodic memory have not been compared systematically between male and female substance-dependent individuals. We administered the Brief Visuospatial Memory Test-Revised (BVMT-R) to 280 substance-dependent HIV+ and HIV- men and women. Groups were comparable on demographic, substance use, and comorbid characteristics. There were no significant main effects of sex or HIV serostatus on BVMT-R performance, but HIV+ women performed significantly more poorly on delayed recall. This effect was most prominent among cocaine-dependent HIV+ women. Our findings are consistent with recent speculation that memory impairment may be more common among HIV+ women, particularly those with a history of cocaine dependence.

Theoretical study of the effect of ionospheric return currents on the electron temperature

NASA Technical Reports Server (NTRS)

Schunk, R. W.; Sojka, J. J.; Bowline, M. D.

1987-01-01

A time-dependent, three-dimensional model of the high-altitude ionosphere is presently used to study the effects of field-aligned ionospheric return currents on auroral electron temperatures for different seasonal and solar cycle conditions, as well as for different upper boundary heat fluxes. The average, large scale, return current densities, which are a few microamps/sq m, are too small to affect auroral electron temperatures. The thermoelectric effect exhibits a pronounced solar cycle and seasonal dependence, and its heat transport corresponds to an upward flow of electron energy which can be either a source or sink of electron energy depending on altitude and geophysical conditions.

Effects of Extinction Context and Retrieval Cues on Renewal of Alcohol-Cue Reactivity Among Alcohol-Dependent Outpatients

PubMed Central

Stasiewicz, Paul R.; Brandon, Thomas H.; Bradizza, Clara M.

2013-01-01

Pavlovian conditioning models have led to cue-exposure treatments for drug abuse. However, conditioned responding to drug stimuli can return (be renewed) following treatment. Animal research and a previous study of social drinkers indicated that extinction is highly context dependent but that renewal could be reduced by the inclusion of a cue from the extinction context. This study extends this research to a clinical sample. Alcohol-dependent outpatients (N = 143) completed an extinction trial to reduce craving and salivation responses to alcohol cues. They were then randomized to renewal tests in either the same context as extinction, a different context, the different context containing an extinction cue, or the different context with cue plus a manipulation to increase the salience of the cue. Contrary to predictions, the different context did not produce the expected renewal effect. Although the generalization of extinction effects beyond the cue-exposure context is a positive clinical finding, it is inconsistent with basic research findings on the context dependence of extinction. Possible explanations for this inconsistency are discussed. PMID:17563145

Voltage-dependent formation of gramicidin channels in lipid bilayers.

PubMed Central

Sandblom, J; Galvanovskis, J; Jilderos, B

2001-01-01

The formation kinetics of gramicidin A channels in lipid bilayer membranes has been characterized as a function of voltage for different solution conditions and membrane composition. The frequency of channel events was measured during the application of voltage ramps and counted in given intervals, a procedure that eliminated the effects of drift in gramicidin concentration. The formation rate was found to increase strongly with voltages up to approximately 50 mV and then to level off slightly. The shape of the voltage dependence was independent of lipid solvent and ramp speed but differed for different ions and different solution concentrations. This suggested an ion occupancy effect on the formation rate that was further supported by the fact that the minimum of the formation rate was shifted toward the equilibrium potential in asymmetric solution concentrations. The effects are explained in terms of a model that contains two contributions to the voltage dependence, a voltage-dependent ion binding to the monomers and a polarization of monomers by the applied electric field and by the occupied ions. The theory is found to give a good fit to experimental data. PMID:11463628

Effects of extinction context and retrieval cues on renewal of alcohol-cue reactivity among alcohol-dependent outpatients.

PubMed

Stasiewicz, Paul R; Brandon, Thomas H; Bradizza, Clara M

2007-06-01

Pavlovian conditioning models have led to cue-exposure treatments for drug abuse. However, conditioned responding to drug stimuli can return (be renewed) following treatment. Animal research and a previous study of social drinkers indicated that extinction is highly context dependent but that renewal could be reduced by the inclusion of a cue from the extinction context. This study extends this research to a clinical sample. Alcohol-dependent outpatients (N = 143) completed an extinction trial to reduce craving and salivation responses to alcohol cues. They were then randomized to renewal tests in either the same context as extinction, a different context, the different context containing an extinction cue, or the different context with cue plus a manipulation to increase the salience of the cue. Contrary to predictions, the different context did not produce the expected renewal effect. Although the generalization of extinction effects beyond the cue-exposure context is a positive clinical finding, it is inconsistent with basic research findings on the context dependence of extinction. Possible explanations for this inconsistency are discussed.

Reexamination of mood-mediation hypothesis of background-music-dependent effects in free recall.

PubMed

Isarida, Toshiko K; Kubota, Takayuki; Nakajima, Saki; Isarida, Takeo

2017-03-01

The present study reexamined the mood-mediation hypothesis for explaining background-music-dependent effects in free recall. Experiments 1 and 2 respectively examined tempo- and tonality-dependent effects in free recall, which had been used as evidence for the mood-mediation hypothesis. In Experiments 1 and 2, undergraduates (n = 75 per experiment) incidentally learned a list of 20 unrelated words presented one by one at a rate of 5 s per word and then received a 30-s delayed oral free-recall test. Throughout the study and test sessions, a piece of music was played. At the time of test, one third of the participants received the same piece of music with the same tempo or tonality as at study, one third heard a different piece with the same tempo or tonality, and one third heard a different piece with a different tempo or tonality. Note that the condition of the same piece with a different tempo or tonality was excluded. Furthermore, the number of sampled pieces of background music was increased compared with previous studies. The results showed neither tempo- nor tonality-dependent effects, but only a background-music-dependent effect. Experiment 3 (n = 40) compared the effects of background music with a verbal association task and focal music (only listening to musical selections) on the participants' moods. The results showed that both the music tempo and tonality influenced the corresponding mood dimensions (arousal and pleasantness). These results are taken as evidence against the mood-mediation hypothesis. Theoretical implications are discussed.

Effects of sounding temperature assimilation on weather forecasting - Model dependence studies

NASA Technical Reports Server (NTRS)

Ghil, M.; Halem, M.; Atlas, R.

1979-01-01

In comparing various methods for the assimilation of remote sounding information into numerical weather prediction (NWP) models, the problem of model dependence for the different results obtained becomes important. The paper investigates two aspects of the model dependence question: (1) the effect of increasing horizontal resolution within a given model on the assimilation of sounding data, and (2) the effect of using two entirely different models with the same assimilation method and sounding data. Tentative conclusions reached are: first, that model improvement as exemplified by increased resolution, can act in the same direction as judicious 4-D assimilation of remote sounding information, to improve 2-3 day numerical weather forecasts. Second, that the time continuous 4-D methods developed at GLAS have similar beneficial effects when used in the assimilation of remote sounding information into NWP models with very different numerical and physical characteristics.

Toxicological Profiling of Highly Purified Single-Walled Carbon Nanotubes with Different Lengths in the Rodent Lung and Escherichia Coli.

PubMed

Wang, Xiang; Lee, Jae-Hyeok; Li, Ruibin; Liao, Yu-Pei; Kang, Joohoon; Chang, Chong Hyun; Guiney, Linda M; Mirshafiee, Vahid; Li, Linjiang; Lu, Jianqin; Xia, Tian; Hersam, Mark C; Nel, André E

2018-06-01

Carbon nanotubes (CNTs) exhibit a number of physicochemical properties that contribute to adverse biological outcomes. However, it is difficult to define the independent contribution of individual properties without purified materials. A library of highly purified single-walled carbon nanotubes (SWCNTs) of different lengths is prepared from the same base material by density gradient ultracentrifugation, designated as short (318 nm), medium (789 nm), and long (1215 nm) SWCNTs. In vitro screening shows length-dependent interleukin-1β (IL-1β) production, in order of long > medium > short. However, there are no differences in transforming growth factor-β1 production in BEAS-2B cells. Oropharyngeal aspiration shows that all the SWCNTs induce profibrogenic effects in mouse lung at 21 d postexposure, but there are no differences between tube lengths. In contrast, these SWCNTs demonstrate length-dependent antibacterial effects on Escherichia coli, with the long SWCNT exerting stronger effects than the medium or short tubes. These effects are reduced by Pluronic F108 coating or supplementing with glucose. The data show length-dependent effects on proinflammatory response in macrophage cell line and antibacterial effects, but not on collagen deposition in the lung. These data demonstrate that over the length scale tested, the biological response to highly purified SWCNTs is dependent on the complexity of the nano/bio interface. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effects of endurance, resistance, and concurrent exercise on learning and memory after morphine withdrawal in rats.

PubMed

Zarrinkalam, Ebrahim; Heidarianpour, Ali; Salehi, Iraj; Ranjbar, Kamal; Komaki, Alireza

2016-07-15

Continuous morphine consumption contributes to the development of cognitive disorders. This work investigates the impacts of different types of exercise on learning and memory in morphine-dependent rats. Forty morphine-dependent rats were randomly divided into five groups: sedentary-dependent (Sed-D), endurance exercise-dependent (En-D), strength exercise-dependent (St-D), and combined (concurrent) exercise-dependent (Co-D). Healthy rats were used as controls (Con). After 10weeks of regular exercise (endurance, strength, and concurrent; each five days per week), spatial and aversive learning and memory were assessed using the Morris water maze and shuttle box tests. The results showed that morphine addiction contributes to deficits in spatial learning and memory. Furthermore, each form of exercise training restored spatial learning and memory performance in morphine-dependent rats to levels similar to those of healthy controls. Aversive learning and memory during the acquisition phase were not affected by morphine addiction or exercise, but were significantly decreased by morphine dependence. Only concurrent training returned the time spent in the dark compartment in the shuttle box test to control levels. These findings show that different types of exercise exert similar effects on spatial learning and memory, but show distinct effects on aversive learning and memory. Further, morphine dependence-induced deficits in cognitive function were blocked by exercise. Therefore, different exercise regimens may represent practical treatment methods for cognitive and behavioral impairments associated with morphine-related disease. Copyright © 2016 Elsevier Inc. All rights reserved.

Corticosterone regulates multiple colour traits in Lacerta [Zootoca] vivipara males.

PubMed

San-Jose, L M; Fitze, P S

2013-12-01

Ornamental colours usually evolve as honest signals of quality, which is supported by the fact that they frequently depend on individual condition. It has generally been suggested that some, but not all types of ornamental colours are condition dependent, indicating that different evolutionary mechanisms underlie the evolution of multiple types of ornamental colours even when these are exhibited by the same species. Stress hormones, which negatively affect condition, have been shown to affect colour traits based on different pigments and structures, suggesting that they mediate condition dependence of multiple ornament types both among and within individuals. However, studies investigating effects of stress hormones on different ornament types within individuals are lacking, and thus, evidence for this hypothesis is scant. Here, we investigated whether corticosterone mediates condition dependence of multiple ornaments by manipulating corticosterone levels and body condition (via food availability) using a two-factorial design and by assessing their effect on multiple colour traits in male common lizards. Corticosterone negatively affected ventral melanin- and carotenoid-based coloration, whereas food availability did not affect coloration, despite its significant effect on body condition. The corticosterone effect on melanin- and carotenoid-based coloration demonstrates the condition dependence of both ornaments. Moreover, corticosterone affected ventral coloration and had no effect on the nonsexually selected dorsal coloration, showing specific effects of corticosterone on ornamental ventral colours. This suggests that corticosterone simultaneously mediates condition dependence of multiple colour traits and that it therefore accounts for covariation among them, which may influence their evolution via correlational selection. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

Fibrinolytic activity and dose-dependent effect of incubating human blood clots in caffeic acid phenethyl ester: in vitro assays.

PubMed

Elnager, Abuzar; Hassan, Rosline; Idris, Zamzuri; Mustafa, Zulkifli; Wan-Arfah, Nadiah; Sulaiman, S A; Gan, Siew Hua; Abdullah, Wan Zaidah

2015-01-01

Background. Caffeic acid phenethyl ester (CAPE) has been reported to possess time-dependent fibrinolytic activity by in vitro assay. This study is aimed at investigating fibrinolytic dose-dependent activity of CAPE using in vitro assays. Methods. Standardized human whole blood (WB) clots were incubated in either blank controls or different concentrations of CAPE (3.75, 7.50, 15.00, 22.50, and 30.00 mM). After 3 hours, D-dimer (DD) levels and WB clot weights were measured for each concentration. Thromboelastography (TEG) parameters were recorded following CAPE incubation, and fibrin morphology was examined under a confocal microscope. Results. Overall, mean DD (μg/mL) levels were significantly different across samples incubated with different CAPE concentrations, and the median pre- and postincubation WB clot weights (grams) were significantly decreased for each CAPE concentration. Fibrin removal was observed microscopically and indicated dose-dependent effects. Based on the TEG test, the Ly30 fibrinolytic parameter was significantly different between samples incubated with two different CAPE concentrations (15.0 and 22.50 mM). The 50% effective dose (ED50) of CAPE (based on DD) was 1.99 mg/mL. Conclusions. This study suggests that CAPE possesses fibrinolytic activity following in vitro incubation and that it has dose-dependent activities. Therefore, further investigation into CAPE as a potential alternative thrombolytic agent should be conducted.

WHY DO THE ACUTE BEHAVIORAL EFFECTS OT TOLUENE IN RATS DEPEND ON THE ROUTE OF EXPOSURE?

EPA Science Inventory

Despite evidence suggesting that the acute effects of organic solvents are related to their concentration in the brain, we have observed route-dependent differences in the acute behavioral effects of toluene. Whereas inhaled toluene disrupts the performance of rats on a visual si...

Sex differences in HIV effects on visual memory among substance-dependent individuals

PubMed Central

Keutmann, Michael K.; Gonzalez, Raul; Maki, Pauline M.; Rubin, Leah H.; Vassileva, Jasmin; Martin, Eileen M.

2016-01-01

HIV’s effects on episodic memory have not been compared systematically between male and female substance-dependent individuals. We administered the Brief Visuospatial Memory Test–Revised (BVMT–R) to 280 substance-dependent HIV+ and HIV− men and women. Groups were comparable on demographic, substance use, and comorbid characteristics. There were no significant main effects of sex or HIV serostatus on BVMT–R performance, but HIV+ women performed significantly more poorly on delayed recall. This effect was most prominent among cocaine-dependent HIV+ women. Our findings are consistent with recent speculation that memory impairment may be more common among HIV+ women, particularly those with a history of cocaine dependence. PMID:27841082

Gender differences in trait aggression in young adults with drug and alcohol dependence compared to the general population.

PubMed

Bácskai, Erika; Czobor, Pál; Gerevich, József

2011-07-01

Data in gender differences in aggression among alcohol and drug dependent subjects are lacking, and no published data are available about gender differences among various subtypes of substance using populations. The goal of this cross-sectional study was to investigate gender differences with regard to types of trait aggression in substance dependent young populations (age: 20-35 years) compared to the general population. Subjects were selected from two clinical samples with a diagnosis of alcohol and drug dependence as well as from a representative sample of the general population. Trait aggression was measured by the four individual subscales of the Buss Perry Aggression Questionnaire (physical-PA, verbal aggression-VA, hostility-H and anger AN) whereas alcohol and drug use were characterized by the AUDIT and EuroADAD scales, respectively. Alcohol and drug dependent subjects showed higher severity on all four subscales of trait aggression compared to the general population. The male-female difference was the highest in the cannabis group. General Linear Model analysis for PA indicated a significant main effect of gender (higher PA for males, p=0.034) with no interaction between substance dependence and gender. For VA, no main effect or interaction for gender was found. Effect sizes for gender difference indicated that while males and females were similar in the control group in the severity in H and A, the level of H and AN was substantially higher in females than in males in the clinical group. These differences between the two genders reached statistical significance in the marijuana group, where female subjects showed a significantly higher severity in these two domains. Compared to the normal sample chronic substance use is associated with higher scores on certain factors of trait aggression, including hostility and anger, in females than in males. Our data suggest that aggression in substance dependent females is more provocable by chronic use of alcohol and drugs than in males. Copyright © 2011 Elsevier Inc. All rights reserved.

Detection of density dependence requires density manipulations and calculation of lambda.

PubMed

Fowler, N L; Overath, R Deborah; Pease, Craig M

2006-03-01

To investigate density-dependent population regulation in the perennial bunchgrass Bouteloua rigidiseta, we experimentally manipulated density by removing adults or adding seeds to replicate quadrats in a natural population for three annual intervals. We monitored the adjacent control quadrats for 14 annual intervals. We constructed a population projection matrix for each quadrat in each interval, calculated lambda, and did a life table response experiment (LTRE) analysis. We tested the effects of density upon lambda by comparing experimental and control quadrats, and by an analysis of the 15-year observational data set. As measured by effects on lambda and on N(t+1/Nt in the experimental treatments, negative density dependence was strong: the population was being effectively regulated. The relative contributions of different matrix elements to treatment effect on lambda differed among years and treatments; overall the pattern was one of small contributions by many different life cycle stages. In contrast, density dependence could not be detected using only the observational (control quadrats) data, even though this data set covered a much longer time span. Nor did experimental effects on separate matrix elements reach statistical significance. These results suggest that ecologists may fail to detect density dependence when it is present if they have only descriptive, not experimental, data, do not have data for the entire life cycle, or analyze life cycle components separately.

Does formal complexity reflect cognitive complexity? Investigating aspects of the Chomsky Hierarchy in an artificial language learning study.

PubMed

Öttl, Birgit; Jäger, Gerhard; Kaup, Barbara

2015-01-01

This study investigated whether formal complexity, as described by the Chomsky Hierarchy, corresponds to cognitive complexity during language learning. According to the Chomsky Hierarchy, nested dependencies (context-free) are less complex than cross-serial dependencies (mildly context-sensitive). In two artificial grammar learning (AGL) experiments participants were presented with a language containing either nested or cross-serial dependencies. A learning effect for both types of dependencies could be observed, but no difference between dependency types emerged. These behavioral findings do not seem to reflect complexity differences as described in the Chomsky Hierarchy. This study extends previous findings in demonstrating learning effects for nested and cross-serial dependencies with more natural stimulus materials in a classical AGL paradigm after only one hour of exposure. The current findings can be taken as a starting point for further exploring the degree to which the Chomsky Hierarchy reflects cognitive processes.

Does Formal Complexity Reflect Cognitive Complexity? Investigating Aspects of the Chomsky Hierarchy in an Artificial Language Learning Study

PubMed Central

Öttl, Birgit; Jäger, Gerhard; Kaup, Barbara

2015-01-01

This study investigated whether formal complexity, as described by the Chomsky Hierarchy, corresponds to cognitive complexity during language learning. According to the Chomsky Hierarchy, nested dependencies (context-free) are less complex than cross-serial dependencies (mildly context-sensitive). In two artificial grammar learning (AGL) experiments participants were presented with a language containing either nested or cross-serial dependencies. A learning effect for both types of dependencies could be observed, but no difference between dependency types emerged. These behavioral findings do not seem to reflect complexity differences as described in the Chomsky Hierarchy. This study extends previous findings in demonstrating learning effects for nested and cross-serial dependencies with more natural stimulus materials in a classical AGL paradigm after only one hour of exposure. The current findings can be taken as a starting point for further exploring the degree to which the Chomsky Hierarchy reflects cognitive processes. PMID:25885790

The impact of background radiation, illumination and temperature on EMF-induced changes of aqua medium properties.

PubMed

Naira, Baghdasaryan; Yerazik, Mikayelyan; Anna, Nikoghosyan; Sinerik, Ayrapetyan

2013-09-01

The effects of extremely low frequency electromagnetic field (ELF EMF) on physicochemical properties of physiological solution at different environmental media were studied. The existence of frequency "windows" at 4 and 8 Hz frequencies of ELF EMF having effects on heat fusion period, hydrogen peroxide (H2O2) formation and oxygen (O2) content of water solution and different dependency on temperature, background radiation and illumination was shown. Obtained data allow us to suggest that EMF-induced effect on water physicochemical properties depends on abovementioned environmental factors. As cell bathing medium is a target for biological effects of ELF EMF, the variability of experimental data on biological effects of EMF, obtained in different laboratories, can be explained by different environmental conditions of experiments, which very often are not considered adequately.

Comparison of Caffeine and d-amphetamine in Cocaine-Dependent Subjects: Differential Outcomes on Subjective and Cardiovascular Effects, Reward Learning, and Salivary Paraxanthine.

PubMed

Lane, Scott D; Green, Charles E; Schmitz, Joy M; Rathnayaka, Nuvan; Fang, Wendy B; Ferré, Sergi; Moeller, F Gerard

2014-01-01

Due to indirect modulation of dopamine transmission, adenosine receptor antagonists may be useful in either treating cocaine use or improving disrupted cognitive-behavioral functions associated with chronic cocaine use. To compare and contrast the stimulant effects of adenosine antagonism to direct dopamine stimulation, we administered 150 mg and 300 mg caffeine, 20 mg amphetamine, and placebo to cocaine-dependent vs. healthy control subjects, matched on moderate caffeine use. Data were obtained on measures of cardiovascular effects, subjective drug effects (ARCI, VAS, DEQ), and a probabilistic reward-learning task sensitive to dopamine modulation. Levels of salivary caffeine and the primary caffeine metabolite paraxanthine were obtained on placebo and caffeine dosing days. Cardiovascular results revealed main effects of dose for diastolic blood pressure and heart rate; follow up tests showed that controls were most sensitive to 300 mg caffeine and 20 mg amphetamine; cocaine-dependent subjects were sensitive only to 300 mg caffeine. Subjective effects results revealed dose × time and dose × group interactions on the ARCI A, ARCI LSD, and VAS 'elated' scales; follow up tests did not show systematic differences between groups with regard to caffeine or d-amphetamine. Large between-group differences in salivary paraxanthine (but not salivary caffeine) levels were obtained under both caffeine doses. The cocaine-dependent group expressed significantly higher paraxanthine levels than controls under 150 mg and 3-4 fold greater levels under 300 mg at 90 min and 150 min post caffeine dose. However, these differences also covaried with cigarette smoking status (not balanced between groups), and nicotine smoking is known to alter caffeine/paraxanthine metabolism via cytochrome P450 enzymes. These preliminary data raise the possibility that adenosine antagonists may affect cocaine-dependent and non-dependent subjects differently. In conjunction with previous preclinical and human studies, the data suggest that adenosine modulating drugs may have value in the treatment of stimulant use disorders.

Investigation on the effects of temperature dependency of material parameters on a thermoelastic loading problem

NASA Astrophysics Data System (ADS)

Kumar, Anil; Mukhopadhyay, Santwana

2017-08-01

The present work is concerned with the investigation of thermoelastic interactions inside a spherical shell with temperature-dependent material parameters. We employ the heat conduction model with a single delay term. The problem is studied by considering three different kinds of time-dependent temperature and stress distributions applied at the inner and outer surfaces of the shell. The problem is formulated by considering that the thermal properties vary as linear function of temperature that yield nonlinear governing equations. The problem is solved by applying Kirchhoff transformation along with integral transform technique. The numerical results of the field variables are shown in the different graphs to study the influence of temperature-dependent thermal parameters in various cases. It has been shown that the temperature-dependent effect is more prominent in case of stress distribution as compared to other fields and also the effect is significant in case of thermal shock applied at the two boundary surfaces of the spherical shell.

Moderate Effects of Same-Sex Legislation on Dependent Employer-Based Insurance Coverage Among Sexual Minorities.

PubMed

Tran, Linda Diem

2016-12-01

A difference-in-difference approach was used to compare the effects of same-sex domestic partnership, civil union, and marriage policies on same- and different-sex partners who could have benefitted from their partners' employer-based insurance (EBI) coverage. Same-sex partners had 78% lower odds (Marginal Effect = -21%) of having EBI compared with different-sex partners, adjusting for socioeconomic and health-related factors. Same-sex partners living in states that recognized same-sex marriage or domestic partnership had 89% greater odds of having EBI compared with those in states that did not recognize same-sex unions (ME = 5%). The impact of same-sex legislation on increasing take-up of dependent EBI coverage among lesbians, gay men, and bisexual individuals was modest, and domestic partnership legislation was equally as effective as same-sex marriage in increasing same-sex partner EBI coverage. Extending dependent EBI coverage to same-sex partners can mitigate gaps in coverage for a segment of the lesbians, gay men, and bisexual population but will not eliminate them. © The Author(s) 2016.

Moderate Effects of Same-Sex Legislation on Dependent Employer-Based Insurance Coverage among Sexual Minorities

PubMed Central

Tran, Linda Diem

2016-01-01

A difference-in-difference approach was used to compare the effects of same-sex domestic partnership, civil union, and marriage policies on same- and different-sex partners who could have benefitted from their partners’ employer-based insurance (EBI) coverage. Same-sex partners had 78% lower odds (ME=-21%) of having EBI compared to different-sex partners, adjusting for socioeconomic and health-related factors. Same-sex partners living in states that recognized same-sex marriage or domestic partnership had 89% greater odds of having EBI compared to those in states that did not recognize same-sex unions (ME=5%). The impact of same-sex legislation on increasing take-up of dependent EBI coverage among lesbians, gay men, and bisexual individuals (LGBs) was modest, and domestic partnership legislation was equally as effective as same-sex marriage in increasing same-sex partner EBI coverage. Extending dependent EBI coverage to same-sex partners can mitigate gaps in coverage for a segment of the LGB population but will not eliminate them. PMID:26762647

Frequency dependence limits divergent evolution by favouring rare immigrants over residents.

PubMed

Bolnick, Daniel I; Stutz, William E

2017-06-08

Two distinct forms of natural selection promote adaptive biological diversity. Divergent selection occurs when different environments favour different phenotypes, leading to increased differences between populations. Negative frequency-dependent selection occurs when rare variants within a population are favoured over common ones, increasing diversity within populations. These two diversifying forces promote genetic variation at different spatial scales, and may act in opposition, but their relative effects remain unclear because they are rarely measured concurrently. Here we show that negative frequency-dependent selection within populations can favor rare immigrants over locally adapted residents. We reciprocally transplanted lake and stream ecotypes of threespine stickleback into lake and stream habitats, while manipulating the relative abundance of residents versus immigrants. We found negative frequency-dependence: survival was highest for the locally rare ecotype, rather than natives. Also, individuals with locally rare major histocompatibility complex (MHC) class IIb genotypes were infected by fewer parasites. This negative frequency-dependent selection will tend to favour rare immigrants over common residents, amplifying the effect of migration and undermining the efficacy of divergent natural selection to drive population differences. The only signal of divergent selection was a tendency for foreign fish to have higher parasite loads than residents, after controlling for MHC genotype rarity. Frequency-dependent ecological interactions have long been thought to promote speciation. Our results suggest a more nuanced view in which negative frequency dependence alters the fate of migrants to promote or constrain evolutionary divergence between populations.

Effects of Meditation on Anxiety and Chemical Dependency.

ERIC Educational Resources Information Center

Wong, Martin R.; And Others

1981-01-01

Studied a non-self-selected sample of chemically dependent people instructed in meditation techniques. Differences established upon training termination were no longer evident in the instructed group after six months. Subjects who reported continuing at least minimal meditative practices, however, showed differences in social adjustment, work…

Characteristic community structure of Florida's subtropical wetlands: the Florida wetland condition index

EPA Science Inventory

Depending upon the classification scheme applied, there are between 10 and 45 different wetland types in Florida. Land use and land cover change has a marked effect on wetland condition, and different wetland types are affected differentially depending on many abiotic and biotic ...

Fibrinolytic Activity and Dose-Dependent Effect of Incubating Human Blood Clots in Caffeic Acid Phenethyl Ester: In Vitro Assays

PubMed Central

Elnager, Abuzar; Hassan, Rosline; Idris, Zamzuri; Mustafa, Zulkifli; Wan-Arfah, Nadiah; Sulaiman, S. A.; Gan, Siew Hua; Abdullah, Wan Zaidah

2015-01-01

Background. Caffeic acid phenethyl ester (CAPE) has been reported to possess time-dependent fibrinolytic activity by in vitro assay. This study is aimed at investigating fibrinolytic dose-dependent activity of CAPE using in vitro assays. Methods. Standardized human whole blood (WB) clots were incubated in either blank controls or different concentrations of CAPE (3.75, 7.50, 15.00, 22.50, and 30.00 mM). After 3 hours, D-dimer (DD) levels and WB clot weights were measured for each concentration. Thromboelastography (TEG) parameters were recorded following CAPE incubation, and fibrin morphology was examined under a confocal microscope. Results. Overall, mean DD (μg/mL) levels were significantly different across samples incubated with different CAPE concentrations, and the median pre- and postincubation WB clot weights (grams) were significantly decreased for each CAPE concentration. Fibrin removal was observed microscopically and indicated dose-dependent effects. Based on the TEG test, the Ly30 fibrinolytic parameter was significantly different between samples incubated with two different CAPE concentrations (15.0 and 22.50 mM). The 50% effective dose (ED50) of CAPE (based on DD) was 1.99 mg/mL. Conclusions. This study suggests that CAPE possesses fibrinolytic activity following in vitro incubation and that it has dose-dependent activities. Therefore, further investigation into CAPE as a potential alternative thrombolytic agent should be conducted. PMID:25664321

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bičiūnas, A.; Arlauskas, A.; Adamonis, J.

We report on terahertz (THz) emission from tellurium crystal surfaces excited by femtosecond optical pulses. Measurements were performed on three differently cut Te samples and with different wavelength optical excitation pulses. THz pulse amplitude dependences on the azimuthal angle measured at various excitation wavelengths have evidenced that three different mechanisms are responsible for THz generation in tellurium: second order nonlinear optical rectification effect, dominating at lower excitation photon energies, as well as transverse and ordinary photo-Dember effects, which emerge at energies larger than 0.9 eV. The shapes of the azimuthal angle dependences were also explained by theoretical model.

Brief early handling increases morphine dependence in adult rats.

PubMed

Vazquez, Vincent; Penit-Soria, Jacqueline; Durand, Claudette; Besson, Marie-Jo; Giros, Bruno; Daugé, Valérie

2006-06-30

Short early manipulations of rodent postnatal environment may trigger long-term effects on neurobiological and behavioural phenotypes in adulthood. However, little is known about such effects of handling on the vulnerability to develop drug dependence. The present study aimed to analyze the long-term effects of a brief handling (1 min) on morphine and ethanol dependence and on the preproenkephalin (PPE) mRNA and mu opioid receptor levels. Handled rats showed a significant increase in morphine (25mg/l) but not ethanol (10%) consumption and preference after 7 weeks and no difference in morphine (2 and 5mg/kg) conditioned place preference. No difference of preproenkephalin mRNA and mu opioid receptor levels was detected in the mesolimbic system between both groups. These data emphasize that human brief handling, which can lead to morphine dependence development, constitutes in itself an experimental treatment and not a control condition.

Individual diet has sex-dependent effects on vertebrate gut microbiota

PubMed Central

Bolnick, Daniel I.; Snowberg, Lisa K.; Hirsch, Philipp E.; Lauber, Christian L.; Org, Elin; Parks, Brian; Lusis, Aldons J.; Knight, Rob; Caporaso, J. Gregory; Svanbäck, Richard

2014-01-01

Vertebrates harbour diverse communities of symbiotic gut microbes. Host diet is known to alter microbiota composition, implying that dietary treatments might alleviate diseases arising from altered microbial composition (‘dysbiosis’). However, it remains unclear whether diet effects are general or depend on host genotype. Here we show that gut microbiota composition depends on interactions between host diet and sex within populations of wild and laboratory fish, laboratory mice and humans. Within each of two natural fish populations (threespine stickleback and Eurasian perch), among-individual diet variation is correlated with individual differences in gut microbiota. However, these diet–microbiota associations are sex dependent. We document similar sex-specific diet–microbiota correlations in humans. Experimental diet manipulations in laboratory stickleback and mice confirmed that diet affects microbiota differently in males versus females. The prevalence of such genotype by environment (sex by diet) interactions implies that therapies to treat dysbiosis might have sex-specific effects. PMID:25072318

Individual diet has sex-dependent effects on vertebrate gut microbiota.

PubMed

Bolnick, Daniel I; Snowberg, Lisa K; Hirsch, Philipp E; Lauber, Christian L; Org, Elin; Parks, Brian; Lusis, Aldons J; Knight, Rob; Caporaso, J Gregory; Svanbäck, Richard

2014-07-29

Vertebrates harbour diverse communities of symbiotic gut microbes. Host diet is known to alter microbiota composition, implying that dietary treatments might alleviate diseases arising from altered microbial composition ('dysbiosis'). However, it remains unclear whether diet effects are general or depend on host genotype. Here we show that gut microbiota composition depends on interactions between host diet and sex within populations of wild and laboratory fish, laboratory mice and humans. Within each of two natural fish populations (threespine stickleback and Eurasian perch), among-individual diet variation is correlated with individual differences in gut microbiota. However, these diet-microbiota associations are sex dependent. We document similar sex-specific diet-microbiota correlations in humans. Experimental diet manipulations in laboratory stickleback and mice confirmed that diet affects microbiota differently in males versus females. The prevalence of such genotype by environment (sex by diet) interactions implies that therapies to treat dysbiosis might have sex-specific effects.

Age, state, environment, and season dependence of senescence in body mass.

PubMed

Kroeger, Svenja B; Blumstein, Daniel T; Armitage, Kenneth B; Reid, Jane M; Martin, Julien G A

2018-02-01

Senescence is a highly variable process that comprises both age-dependent and state-dependent components and can be greatly affected by environmental conditions. However, few studies have quantified the magnitude of age-dependent and state-dependent senescence in key life-history traits across individuals inhabiting different spatially structured and seasonal environments. We used longitudinal data from wild female yellow-bellied marmots ( Marmota flaviventer ), living in two adjacent environments that differ in elevation and associated phenology, to quantify how age and individual state, measured as "time to death," affect body mass senescence in different environments. Further, we quantified how patterns of senescence differed between two biologically distinct seasons, spring, and late summer. Body mass senescence had an age-dependent component, expressed as a decrease in mass in old age. Overall, estimated age-dependent senescence was greater in females living in the more favorable lower elevation environment, than in the harsher higher elevation environment, and greater in late summer than in spring. Body mass senescence also had a state-dependent component, captured by effects of time to death, but only in the more favorable lower elevation environment. In spring, body mass gradually decreased from 2 years before death, whereas in late summer, state-dependent effects were expressed as a terminal decrease in body mass in the last year of life. Contrary to expectations, we found that senescence was more likely to be observed under more favorable environmental conditions, rather than under harsher conditions. By further demonstrating that senescence patterns differ among seasons, our results imply that within-year temporal environmental variation must be considered alongside spatial environmental variation in order to characterize and understand the pattern and magnitude of senescence in wild populations.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Richter, Christian; Pawelke, Joerg; Karsch, Leonhard

Purpose: The aim of this article is to investigate the energy dependence of the radiochromic film type, Gafchromic EBT-1, when scanned with a flatbed scanner for film readout. Methods: Dose response curves were determined for 12 different beam qualities ranging from a 10 kVp x-ray beam to a 15 MVp x-ray beam and include also two high energy electron beam qualities (6 and 18 MeV). The dose responses measured as net optical density (netOD) for the different beam qualities were normalized to the response of a reference beam quality (6 MVp). Results: A strong systematic energy dependence of the filmmore » response was found. The lower the effective beam energy, the less sensitive the EBT-1 films get. The maximum decrease in dose for the same film response between the 25 kVp and 6 MVp beam qualities was 44%. Additionally, a difference in energy dependence for different doses was discovered, meaning that higher doses show a smaller dependency on energy than lower doses. The maximum decrease in the normalized netOD was found to be 25% for a dose of 0.5 Gy relative to the normalized netOD for 10 Gy. Moreover, a scaling procedure is introduced, allowing the correction of the energy dependence for the investigated beam qualities and also for comparable x-ray beam qualities within the energy range studied. Conclusions: A strong energy dependence for EBT-1 radiochromic films was found. The films were readout with a flatbed scanner. If the effective beam energy is known, the energy dependence can be corrected with the introduced scaling procedure. Further investigation of the influence of the spectral band of the readout device on energy dependence is needed to understand the reason for the different energy dependences found in this and previous works.« less

Gender differences in the effects of ADH1B and ALDH2 polymorphisms on alcoholism.

PubMed

Kimura, Mitsuru; Miyakawa, Tomohiro; Matsushita, Sachio; So, Mirai; Higuchi, Susumu

2011-11-01

Gender differences are known to exist in the prevalence, characteristics, and course of alcohol dependence. Elucidating gender differences in the characteristics of alcohol dependence is important in gender-based medicine and may improve treatment outcomes. Many studies have shown that genetic factors are associated with the risk of alcohol dependence in both genders. Polymorphisms of alcohol dehydrogenase-1B (ADH1B) and aldehyde dehydrogenase-2 (ALDH2) are strong genetic determinants of alcohol dependence. This study aimed to clarify gender differences in the effects of ADH1B and ALDH2 polymorphism on the development of alcohol dependence. Subjects were 200 female alcoholics and 415 male alcoholics hospitalized in Kurihama Alcoholism Center. Clinical information and background data were obtained by chart review. ALDH2 and ADH1B genotyping was performed by the polymerase chain reaction-restriction fragment length polymorphism method. The onset age of female alcoholics with inactive ALDH2 genotype was significantly lower than those with active ALDH2 genotype, but the onset age did not differ between the inactive and active ALDH2 group in male alcoholics. The difference in onset age between the ADH1B genotype groups did not reach significant levels. The prevalence of comorbid psychiatric disorders, including major depression, eating disorder, panic disorder, and borderline personality disorder, was significantly higher in female alcoholics with inactive ALDH2 or superactive ADH1B than in those with active ALDH2 or normal ADH1B. ALDH2 polymorphism appears to have contrasting effects on the development of alcoholism in women and men. One possible reason for this gender difference may be the high prevalence of psychiatric comorbidities in female alcoholics with inactive ALDH2. Copyright © 2011 by the Research Society on Alcoholism.

Tunable Infrared Semiconductor Lasers

DTIC Science & Technology

2013-12-20

stripe to different positions of an addressable chirped, location-dependent period grating to select the different lasing wavelengths. Interferometric...grating or vernier effects. Our tuning mechanism is to shift the pump stripe to different positions of an addressable chirped, location-dependent period... stripe is applied and the lateral direction is the perpendicular direction across the pump stripe and parallel to the grating lines.  The chirped

Main Properties of Forbush Effects Related to High-Speed Streams from Coronal Holes

NASA Astrophysics Data System (ADS)

Melkumyan, A. A.; Belov, A. V.; Abunina, M. A.; Abunin, A. A.; Eroshenko, E. A.; Oleneva, V. A.; Yanke, V. G.

2018-03-01

The IZMIRAN database of Forbush effects and interplanetary disturbances was used to study features of the action of high-speed solar wind streams from coronal holes on cosmic rays. Three hundred and fifty Forbush effects created by coronal holes without other actions were distinguished. The mean values and distributions have been found for different characteristics of events from this group and compared with all Forbush effects and Forbush effects caused by coronal ejections. Despite the great differences in high-speed streams from coronal holes, this group turned out to be more compact and uniform as compared to events related to coronal ejections. Regression dependences and correlation relations between different parameters of events for the studied groups have been obtained. It has been shown that Forbush effects caused by coronal ejections depend considerably more strongly on the characteristics of interplanetary disturbances as compared to Forbush effects related to coronal holes. This suggests a significant difference between the modulation mechanisms of Forbush effects of different types and corroborates earlier conclusions based on indirect data.

Pancreatic Effects of a Bruton's Tyrosine Kinase Small-molecule Inhibitor in Rats Are Strain-dependent.

PubMed

Bhaskaran, Manoj; Cornwell, Paul D; Sorden, Steven D; Elwell, Michael R; Russell, Natalie R; Pritt, Michael L; Vahle, John L

2018-01-01

Inhibitors of Bruton's tyrosine kinase (BTK) are under development as potential therapies for various autoimmune diseases. In repeat-dose toxicity studies, small-molecule BTK inhibitors (BTKi) have been reported to cause a constellation of histologic effects at the pancreatic endocrine-exocrine interface in male rats; however, similar findings were not reported in other species. Since the BTKi-induced pancreatic effect is morphologically similar to well-documented spontaneous changes (predominantly characterized by insular/peri-insular hemorrhage, pigment deposition, chronic inflammation, and fibrosis) that are known to vary by rat strain, we investigated potential strain-dependent differences in the pancreatic effects of a small-molecule BTKi, LY3337641. Following 13 weeks of LY3337641 treatment, Crl:CD(SD) rats were most sensitive, Crl:WI(Han) rats were of intermediate sensitivity, and Hsd:SD rats were least sensitive. These strain differences appear to be related to differences in rate of weight gain across strains and sexes; however, a definitive mechanism was not determined. This study demonstrated that BTKi-induced pancreatic effects were highly dependent on rat strain and correlated with differences in the incidence and severity of the spontaneous background change. When considered with the lack of pancreas effects in nonrat species, these changes in rats are unlikely predictive of similar changes in humans administered a BTK inhibitor.

Rotavirus capsid VP6 tubular and spherical nanostructures act as local adjuvants when co-delivered with norovirus VLPs.

PubMed

Malm, M; Heinimäki, S; Vesikari, T; Blazevic, V

2017-09-01

A subunit protein vaccine candidate based on norovirus (NoV) virus-like particles (VLPs) and rotavirus (RV) VP6 protein against acute childhood gastroenteritis has been proposed recently. RV VP6 forms different oligomeric nanostructures, including tubes and spheres when expressed in vitro, which are highly immunogenic in different animal models. We have shown recently that recombinant VP6 nanotubes have an adjuvant effect on immunogenicity of NoV VLPs in mice. In this study, we investigated if the adjuvant effect is dependent upon a VP6 dose or different VP6 structural assemblies. In addition, local and systemic adjuvant effects as well as requirements for antigen co-delivery and co-localization were studied. The magnitude and functionality of NoV GII.4-specific antibodies and T cell responses were tested in mice immunized with GII.4 VLPs alone or different combinations of VLPs and VP6. A VP6 dose-dependent adjuvant effect on GII.4-specific antibody responses was observed. The adjuvant effect was found to be strictly dependent upon co-administration of NoV GII.4 VLPs and VP6 at the same anatomic site and at the same time. However, the adjuvant effect was not dependent on the types of oligomers used, as both nanotubes and nanospheres exerted adjuvant effect on GII.4-specific antibody generation and, for the first time, T cell immunity. These findings elucidate the mechanisms of VP6 adjuvant effect in vivo and support its use as an adjuvant in a combination NoV and RV vaccine. © 2017 The Authors. Clinical & Experimental Immunology published by John Wiley & Sons Ltd on behalf of British Society for Immunology.

Direct effects dominate responses to climate perturbations in grassland plant communities.

PubMed

Chu, Chengjin; Kleinhesselink, Andrew R; Havstad, Kris M; McClaran, Mitchel P; Peters, Debra P; Vermeire, Lance T; Wei, Haiyan; Adler, Peter B

2016-06-08

Theory predicts that strong indirect effects of environmental change will impact communities when niche differences between competitors are small and variation in the direct effects experienced by competitors is large, but empirical tests are lacking. Here we estimate negative frequency dependence, a proxy for niche differences, and quantify the direct and indirect effects of climate change on each species. Consistent with theory, in four of five communities indirect effects are strongest for species showing weak negative frequency dependence. Indirect effects are also stronger in communities where there is greater variation in direct effects. Overall responses to climate perturbations are driven primarily by direct effects, suggesting that single species models may be adequate for forecasting the impacts of climate change in these communities.

Neutron-proton effective mass splitting in terms of symmetry energy and its density slope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chakraborty, S.; Sahoo, B.; Sahoo, S., E-mail: sukadevsahoo@yahoo.com

2015-01-15

Using a simple density-dependent finite-range effective interaction having Yukawa form, the density dependence of isoscalar and isovector effective masses is studied. The isovector effective mass is found to be different for different pairs of like and unlike nucleons. Using HVH theorem, the neutron-proton effective mass splitting is represented in terms of symmetry energy and its density slope. It is again observed that the neutron-proton effective mass splitting has got a positive value when isoscalar effective mass is greater than the isovector effective mass and has a negative value for the opposite case. Furthermore, the neutron-proton effective mass splitting is foundmore » to have a linear dependence on asymmetry β. The second-order symmetry potential has a vital role in the determination of density slope of symmetry energy but it does not have any contribution on neutron-proton effective mass splitting. The finite-range effective interaction is compared with the SLy2, SKM, f{sub −}, f{sub 0}, and f{sub +} forms of interactions.« less

Adolescent and Adult Rats Differ in the Amnesic Effects of Acute Ethanol in Two Hippocampus-Dependent Tasks: Trace and Contextual Fear Conditioning

PubMed Central

Hunt, Pamela S.; Barnet, Robert C.

2015-01-01

Experience-produced deficits in trace conditioning and context conditioning have been useful tools for examining the role of the hippocampus in learning. It has also been suggested that learning in these tasks is especially vulnerable to neurotoxic effects of alcohol during key developmental periods such as adolescence. In five experiments we systematically examined the presence and source of age-dependent vulnerability to the memory-disrupting effects of acute ethanol in trace conditioning and contextual fear conditioning. In Experiment 1a pre-training ethanol disrupted trace conditioning more strongly in adolescent (postnatal day, PD30-35) than adult rats (PD65-75). In Experiment 1b when pre-training ethanol was accompanied by pre-test ethanol no deficit in trace conditioning was observed in adolescents, suggesting that state-dependent retrieval failure mediated ethanol's disruption of trace conditioning at this age. Experiments 2a and 2b examined the effect of ethanol pretreatment on context conditioning. Here, adult but not adolescent rats were impaired in conditioned freezing to context cues. Experiment 2c explored state-dependency of this effect. Pre-training ethanol continued to disrupt context conditioning in adults even when ethanol was also administered prior to test. Collectively these findings reveal clear age-dependent and task-dependent vulnerabilities in ethanol's disruptive effects on hippocampus-dependent memory. Adolescents were more disrupted by ethanol in trace conditioning than adults, and adults were more disrupted by ethanol in context conditioning than adolescents. We suggest that adolescents may be more susceptible to changes in internal state (state-dependent retrieval failure) than adults and that ethanol disrupted performance in trace and context conditioning through different mechanisms. Relevance of these findings to theories of hippocampus function is discussed. PMID:26192910

External and internal facial features modulate processing of vertical but not horizontal spatial relations.

PubMed

Meinhardt, Günter; Kurbel, David; Meinhardt-Injac, Bozana; Persike, Malte

2018-03-22

Some years ago an asymmetry was reported for the inversion effect for horizontal (H) and vertical (V) relational face manipulations (Goffaux & Rossion, 2007). Subsequent research examined whether a specific disruption of long-range relations underlies the H/V inversion asymmetry (Sekunova & Barton, 2008). Here, we tested how detection of changes in interocular distance (H) and eye height (V) depends on cardinal internal features and external feature surround. Results replicated the H/V inversion asymmetry. Moreover, we found very different face cue dependencies for both change types. Performance and inversion effects did not depend on the presence of other face cues for detecting H changes. In contrast, accuracy for detecting V changes strongly depended on internal and external features, showing cumulative improvement when more cues were added. Inversion effects were generally large, and larger with external feature surround. The cue independence in detecting H relational changes indicates specialized local processing tightly tuned to the eyes region, while the strong cue dependency in detecting V relational changes indicates a global mechanism of cue integration across different face regions. These findings suggest that the H/V asymmetry of the inversion effect rests on an H/V anisotropy of face cue dependency, since only the global V mechanism suffers from disruption of cue integration as the major effect of face inversion. Copyright © 2018. Published by Elsevier Ltd.

Working memory differences in long-distance dependency resolution

PubMed Central

Nicenboim, Bruno; Vasishth, Shravan; Gattei, Carolina; Sigman, Mariano; Kliegl, Reinhold

2015-01-01

There is a wealth of evidence showing that increasing the distance between an argument and its head leads to more processing effort, namely, locality effects; these are usually associated with constraints in working memory (DLT: Gibson, 2000; activation-based model: Lewis and Vasishth, 2005). In SOV languages, however, the opposite effect has been found: antilocality (see discussion in Levy et al., 2013). Antilocality effects can be explained by the expectation-based approach as proposed by Levy (2008) or by the activation-based model of sentence processing as proposed by Lewis and Vasishth (2005). We report an eye-tracking and a self-paced reading study with sentences in Spanish together with measures of individual differences to examine the distinction between expectation- and memory-based accounts, and within memory-based accounts the further distinction between DLT and the activation-based model. The experiments show that (i) antilocality effects as predicted by the expectation account appear only for high-capacity readers; (ii) increasing dependency length by interposing material that modifies the head of the dependency (the verb) produces stronger facilitation than increasing dependency length with material that does not modify the head; this is in agreement with the activation-based model but not with the expectation account; and (iii) a possible outcome of memory load on low-capacity readers is the increase in regressive saccades (locality effects as predicted by memory-based accounts) or, surprisingly, a speedup in the self-paced reading task; the latter consistent with good-enough parsing (Ferreira et al., 2002). In sum, the study suggests that individual differences in working memory capacity play a role in dependency resolution, and that some of the aspects of dependency resolution can be best explained with the activation-based model together with a prediction component. PMID:25852623

Working memory differences in long-distance dependency resolution.

PubMed

Nicenboim, Bruno; Vasishth, Shravan; Gattei, Carolina; Sigman, Mariano; Kliegl, Reinhold

2015-01-01

There is a wealth of evidence showing that increasing the distance between an argument and its head leads to more processing effort, namely, locality effects; these are usually associated with constraints in working memory (DLT: Gibson, 2000; activation-based model: Lewis and Vasishth, 2005). In SOV languages, however, the opposite effect has been found: antilocality (see discussion in Levy et al., 2013). Antilocality effects can be explained by the expectation-based approach as proposed by Levy (2008) or by the activation-based model of sentence processing as proposed by Lewis and Vasishth (2005). We report an eye-tracking and a self-paced reading study with sentences in Spanish together with measures of individual differences to examine the distinction between expectation- and memory-based accounts, and within memory-based accounts the further distinction between DLT and the activation-based model. The experiments show that (i) antilocality effects as predicted by the expectation account appear only for high-capacity readers; (ii) increasing dependency length by interposing material that modifies the head of the dependency (the verb) produces stronger facilitation than increasing dependency length with material that does not modify the head; this is in agreement with the activation-based model but not with the expectation account; and (iii) a possible outcome of memory load on low-capacity readers is the increase in regressive saccades (locality effects as predicted by memory-based accounts) or, surprisingly, a speedup in the self-paced reading task; the latter consistent with good-enough parsing (Ferreira et al., 2002). In sum, the study suggests that individual differences in working memory capacity play a role in dependency resolution, and that some of the aspects of dependency resolution can be best explained with the activation-based model together with a prediction component.

Time-dependent view of an isotope effect in electron-nuclear nonequilibrium dynamics with applications to N2.

PubMed

Ajay, Jayanth S; Komarova, Ksenia G; Remacle, Francoise; Levine, R D

2018-06-05

Isotopic fractionation in the photodissociation of N 2 could explain the considerable variation in the 14 N/ 15 N ratio in different regions of our galaxy. We previously proposed that such an isotope effect is due to coupling of photoexcited bound valence and Rydberg electronic states in the frequency range where there is strong state mixing. We here identify features of the role of the mass in the dynamics through a time-dependent quantum-mechanical simulation. The photoexcitation of N 2 is by an ultrashort pulse so that the process has a sharply defined origin in time and so that we can monitor the isolated molecule dynamics in time. An ultrafast pulse is necessarily broad in frequency and spans several excited electronic states. Each excited molecule is therefore not in a given electronic state but in a superposition state. A short time after excitation, there is a fairly sharp onset of a mass-dependent large population transfer when wave packets on two different electronic states in the same molecule overlap. This coherent overlap of the wave packets on different electronic states in the region of strong coupling allows an effective transfer of population that is very mass dependent. The extent of the transfer depends on the product of the populations on the two different electronic states and on their relative phase. It is as if two molecules collide but the process occurs within one molecule, a molecule that is simultaneously in both states. An analytical toy model recovers the (strong) mass and energy dependence.

Effects of Alzheimer’s Disease in the Prediagnosis Period on Financial Outcomes

DTIC Science & Technology

2017-10-01

merged data; derived key dependent and independent variables and calculated descriptive statistics; and performed initial analyses of the effect of AD on...during the period before it is diagnosable on financial outcomes differ depending on whether the financial head of household is afflicted or the spouse

Pressure effect on magnetic susceptibility of LaCoO3

NASA Astrophysics Data System (ADS)

Panfilov, A. S.; Grechnev, G. E.; Zhuravleva, I. P.; Lyogenkaya, A. A.; Pashchenko, V. A.; Savenko, B. N.; Novoselov, D.; Prabhakaran, D.; Troyanchuk, I. O.

2018-04-01

The effect of pressure on magnetic properties of LaCoO3 is studied experimentally and theoretically. The pressure dependence of magnetic susceptibility χ of LaCoO3 is obtained by precise measurements of χ as a function of the hydrostatic pressure P up to 2 kbar in the temperature range from 78 K to 300 K. A pronounced magnitude of the pressure effect is found to be negative in sign and strongly temperature dependent. The obtained experimental data are analysed by using a two-level model and DFT+U calculations of the electronic structure of LaCoO3. In particular, the fixed spin moment method was employed to obtain a volume dependence of the total energy difference Δ between the low spin and the intermediate spin states of LaCoO3. Analysis of the obtained experimental χ(P) dependence within the two-level model, as well as our DFT+U calculations, have revealed the anomalous large decrease in the energy difference Δ with increasing of the unit cell volume. This effect, taking into account a thermal expansion, can be responsible for the temperatures dependence of Δ, predicting its vanishing near room temperature.

Sex differences in the effects of juvenile and adult diet on age-dependent reproductive effort.

PubMed

Houslay, T M; Hunt, J; Tinsley, M C; Bussière, L F

2015-05-01

Sexual selection should cause sex differences in patterns of resource allocation. When current and future reproductive effort trade off, variation in resource acquisition might further cause sex differences in age-dependent investment, or in sensitivity to changes in resource availability over time. However, the nature and prevalence of sex differences in age-dependent investment remain unclear. We manipulated resource acquisition at juvenile and adult stages in decorated crickets, Gryllodes sigillatus, and assessed effects on sex-specific allocation to age-dependent reproductive effort (calling in males, fecundity in females) and longevity. We predicted that the resource and time demands of egg production would result in relatively consistent female strategies across treatments, whereas male investment should depend sharply on diet. Contrary to expectations, female age-dependent reproductive effort diverged substantially across treatments, with resource-limited females showing much lower and later investment in reproduction; the highest fecundity was associated with intermediate lifespans. In contrast, long-lived males always signalled more than short-lived males, and male age-dependent reproductive effort did not depend on diet. We found consistently positive covariance between male reproductive effort and lifespan, whereas diet altered this covariance in females, revealing sex differences in the benefits of allocation to longevity. Our results support sex-specific selection on allocation patterns, but also suggest a simpler alternative: males may use social feedback to make allocation decisions and preferentially store resources as energetic reserves in its absence. Increased calling effort with age therefore could be caused by gradual resource accumulation, heightened mortality risk over time, and a lack of feedback from available mates. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

A study of the effect of space-dependent neutronics on stochastically-induced bifurcations in BWR dynamics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Analytis, G.T.

1995-09-01

A non-linear one-group space-dependent neutronic model for a finite one-dimensional core is coupled with a simple BWR feed-back model. In agreement with results obtained by the authors who originally developed the point-kinetics version of this model, we shall show numerically that stochastic reactivity excitations may result in limit-cycles and eventually in a chaotic behaviour, depending on the magnitude of the feed-back coefficient K. In the framework of this simple space-dependent model, the effect of the non-linearities on the different spatial harmonics is studied and the importance of the space-dependent effects is exemplified and assessed in terms of the importance ofmore » the higher harmonics. It is shown that under certain conditions, when the limit-cycle-type develop, the neutron spectra may exhibit strong space-dependent effects.« less

Vicinage effect in the energy loss of H2 dimers: Experiment and calculations based on time-dependent density-functional theory

NASA Astrophysics Data System (ADS)

Koval, N. E.; Borisov, A. G.; Rosa, L. F. S.; Stori, E. M.; Dias, J. F.; Grande, P. L.; Sánchez-Portal, D.; Muiño, R. Díez

2017-06-01

We present a combined theoretical and experimental study of the energy loss of H2+ molecular ions interacting with thin oxide and carbon films. As a result of quantum mechanical interference of the target electrons, the energy loss of a molecular projectile differs from the sum of the energy losses of individual atomic projectiles. This difference is known as the vicinage effect. Calculations based on the time-dependent density functional theory allow the first-principles description of the dynamics of target excitations produced by the correlated motion of the nucleons forming the molecule. We investigate in detail the dependence of the vicinage effect on the speed and charge state of the projectile and find an excellent agreement between calculated and measured data.

Preliminary evidence that exercise dependence is associated with blunted cardiac and cortisol reactions to acute psychological stress.

PubMed

Heaney, Jennifer L J; Ginty, Annie T; Carroll, Douglas; Phillips, Anna C

2011-02-01

Low or blunted cardiovascular and cortisol reactions to acute psychological stress have been shown to characterise those with a tobacco or alcohol dependency. The present study tested the hypothesis that exercise dependency would be similarly associated with blunted reactivity. Young female exercisers (N=219) were screened by questionnaire for exercise dependence. Ten women with probable exercise dependence and 10 non dependent controls were selected for laboratory stress testing. Cardiovascular activity and salivary cortisol were measured at rest and in response to a 10-min mental arithmetic stress task. The exercise dependent women showed blunted cardiac reactions to the stress task and blunted cortisol at 10, 20, and 30 minute post stress exposure. These effects could not be accounted for in terms of group differences in stress task performance, nor could the cardiac effects be attributed to group differences in cardio-respiratory fitness. It would seem that low stress reactivity is characteristic of a wide range of dependencies, and is not confined to substance dependence. Our results offer further support for the hypothesis that blunted stress reactivity may be a peripheral marker of a central motivational dysregulation. Copyright © 2010 Elsevier B.V. All rights reserved.

Differences in Scholastic Achievement of Public, Private Government-Dependent, and Private Independent Schools: A Cross-National Analysis

ERIC Educational Resources Information Center

Dronkers, Jaap; Robert, Peter

2008-01-01

The gross differences in scholastic achievement among public, private government-dependent, and private independent schools in 22 countries are analyzed with Programme for International Student Assessment 2000 data. In a multilevel approach, the authors estimate these sector effects, controlling for sociological characteristics of students and…

Extreme Unconditional Dependence Vs. Multivariate GARCH Effect in the Analysis of Dependence Between High Losses on Polish and German Stock Indexes

NASA Astrophysics Data System (ADS)

Rokita, Pawel

Classical portfolio diversification methods do not take account of any dependence between extreme returns (losses). Many researchers provide, however, some empirical evidence for various assets that extreme-losses co-occur. If the co-occurrence is frequent enough to be statistically significant, it may seriously influence portfolio risk. Such effects may result from a few different properties of financial time series, like for instance: (1) extreme dependence in a (long-term) unconditional distribution, (2) extreme dependence in subsequent conditional distributions, (3) time-varying conditional covariance, (4) time-varying (long-term) unconditional covariance, (5) market contagion. Moreover, a mix of these properties may be present in return time series. Modeling each of them requires different approaches. It seams reasonable to investigate whether distinguishing between the properties is highly significant for portfolio risk measurement. If it is, identifying the effect responsible for high loss co-occurrence would be of a great importance. If it is not, the best solution would be selecting the easiest-to-apply model. This article concentrates on two of the aforementioned properties: extreme dependence (in a long-term unconditional distribution) and time-varying conditional covariance.

Effects of inorganic lead on the differentiation and growth of cultured hippocampal and neuroblastoma cells.

PubMed

Audesirk, T; Audesirk, G; Ferguson, C; Shugarts, D

1991-01-01

Lead exposure has devastating effects on the developing nervous system, and has been implicated in variety of behavioral and cognitive deficits as well as neural morphological abnormalities. Since lead impacts many calcium-dependent processes, one likely mechanism of lead toxicity is its disruption of calcium dependent processes, among which is neuronal differentiation. We investigated the effects of inorganic lead on survival and several parameters of differentiation of cultured neurons. Three different cell types were used: Rat hippocampal neurons (a primary CNS cell type), B50 rat neuroblastoma cells (a transformed CNS-derived cell line), and N1E-115 mouse neuroblastoma cells (a transformed peripherally-derived cell line). Lead concentrations ranged from low nM to 1 mM. Lead effects differed considerably among the three cell types, with B50 cells least affected. Lead effects were generally multimodal, with fewest effects observed at intermediate concentrations. Lead inhibited neurite initiation in hippocampal neurons, but stimulated initiation in N1E-115 cells. In those cells that differentiated, lead increased dendrite numbers in hippocampal neurons and neurite numbers in N1E-115 cells. Lead exposure increased both the length and the degree of branching of axons in hippocampal neurons and the length of neurites in N1E-115 cells. We hypothesize that lead impacts multiple regulatory processes that influence neuron survival and differentiation, and that its effects show differing dose-dependencies. The differing responses of the different cell types to lead suggests that differentiation may be regulated in different ways by the three types of cells. Alternatively, or additionally, the cell types may differ in their ability to compensate for, sequester, or expel lead.

[Difference in action sites between mecamylamine and hexamethonium on nicotinic receptors of sympathetic neurons].

PubMed

Liu, Wei; Zheng, Jian-Quan; Liu, Zhen-Wei; Li, Li-Jun; Wan, Qin; Liu, Chuan-Gui

2002-12-25

To compare the difference in action sites between mecamylamine (MEC) and hexamethonium (HEX) on nicotinic receptors of sympathetic neurons, we investigated the effects of MEC and HEX on the nicotine-induced currents in cultured superior cervical ganglion neurons by whole-cell patch clamp technique. The IC(50) of MEC and HEX for antagonizing the effect of 0.08 mmol/L nicotine was 0.0012 and 0.0095 mmol/L, respectively. Both MEC and HEX accelerated the desensitization of nicotinic receptors. Furthermore, by comparing their effects at holding potentials 30, 70 and 110 mV, it was indicated that their suppressing effect on the nicotine-induced currents was voltage-dependent. However, different from that of HEX, the inhibitory effect of MEC increased with administering the mixture of MEC and nicotine at intervals of 3 min, indicating a use-dependent effect of MEC. It is concluded that the action site of MEC on nicotinic receptors of sympathetic neurons is different from that of HEX.

On the dependency of the decay of ground motion peak values with distance for small and large earthquakes

NASA Astrophysics Data System (ADS)

Dujardin, Alain; Courboulex, Françoise; Causse, Matthieu; Traversa, Paola; Monfret, Tony

2013-04-01

Ground motion decay with distance presents a clear magnitude dependence, PGA values of small events decreasing faster than those of larger events. This observation is now widely accepted and often taken into account in recent ground motion prediction equations (Anderson 2005, Akkar & Bommer 2010). The aim of this study is to investigate the origin of this dependence, which has not been clearly identified yet. Two main hypotheses are considered. On one hand the difference of ground motion decay is related to an attenuation effect, on the other hand the difference is related to an effect of extended fault (Anderson 2000). To study the role of attenuation, we realized synthetic tests using the stochastic simulation program SMSIM from Boore (2005). We build a set of simulations from several magnitudes and epicentral distances, and observe that the decay in PGA values is strongly dependent on the spectral shape of the Fourier spectra, which in turn strongly depends on the attenuation factor (Q(f) or kappa). We found that, for a point source approximation and an infinite value of Q (no attenuation) there is no difference between small and large events and that this difference increases when Q decreases. Theses results show that the influence of attenuation on spectral shape is different for earthquakes of different magnitude. In fact the influence of attenuation, which is more important at higher frequency, is larger for small earthquakes, whose Fourier acceleration spectrum has predominantly higher frequencies. We then study the effect of extended source using complete waveform simulations in a 1D model. We find that when the duration of the source time function increases, there is a larger probability to obtain large PGA values at equivalent distances. This effect could also play an important role in the PGA decay with magnitude and distance. Finally we compare these results with real datasets from the Japanese accelerometric network KIK-net.

Effect of light on colour and reaction of nitrite in sliced pork bologna under different chilled storage temperatures.

PubMed

Carballo, J; Cavestany, M; Jiménez-Colmenero, F

1991-01-01

The effect of different lighting conditions (darkness and exposure to 1900 ± 100 lux) on colour stability, conversion of added nitrite (residual nitrite, nitrite converted to nitrate, nitroso heme pigments, and protein-bound nitrite) and oxidative rancidity (2-thiobarbituric acid index) in sliced, vacuum-packaged pork bologna as a function of storage temperature (0 ± 1°C and 7 ± 1°C) was studied. Colour (redness) losses over the storage period were more dependent upon photochemical processes than on thermal processes, and the action of temperature on colour was attributable to its effect on microbial growth, which in turn also affects oxygen availability. Conversion of nitrite into the different fractions studied was chiefly temperature-dependent, but exposure to light lowered the residual nitrite content. Nevertheless, the effect of illumination on the constant rate of residual nitrite depletion was dependent on the storage temperature. Recovery of the added nitrite, i.e. the total of the nitrite in all the fractions combined, was highly dependent upon fluctuations in the residual nitrite levels and varied over the storage period. Under the conditions of the experiment, photo-oxidation did not appear to be a determining factor in lipid oxidation. Copyright © 1991. Published by Elsevier Ltd.

The effect of intrinsic muscular nonlinearities on the energetics of locomotion in a computational model of an anguilliform swimmer.

PubMed

Hamlet, Christina; Fauci, Lisa J; Tytell, Eric D

2015-11-21

Animals move through their environments using muscles to produce force. When an animal׳s nervous system activates a muscle, the muscle produces different amounts of force depending on its length, its shortening velocity, and its time history of force production. These muscle forces interact with forces from passive tissue properties and forces from the external environment. Using an integrative computational model that couples an elastic, actuated model of an anguilliform, lamprey-like swimmer with a surrounding Navier-Stokes fluid, we study the effects of this coupling between the muscle force and the body motion. Swimmers with different forms of this coupling can achieve similar motions, but use different amounts of energy. The velocity dependence is the most important property of the ones we considered for reducing energy costs and helping us to stabilize oscillations. These effects are strongly influenced by how rapidly the muscle deactivates; if force decays too slowly, muscles on opposite sides of the body end up fighting each other, increasing energy cost. Work-dependent deactivation, an effect that causes a muscle to deactivate more rapidly if it has recently produced mechanical work, works together with the velocity dependence to reduce the energy cost of swimming. Copyright © 2015 Elsevier Ltd. All rights reserved.

Model dependence and its effect on ensemble projections in CMIP5

NASA Astrophysics Data System (ADS)

Abramowitz, G.; Bishop, C.

2013-12-01

Conceptually, the notion of model dependence within climate model ensembles is relatively simple - modelling groups share a literature base, parametrisations, data sets and even model code - the potential for dependence in sampling different climate futures is clear. How though can this conceptual problem inform a practical solution that demonstrably improves the ensemble mean and ensemble variance as an estimate of system uncertainty? While some research has already focused on error correlation or error covariance as a candidate to improve ensemble mean estimates, a complete definition of independence must at least implicitly subscribe to an ensemble interpretation paradigm, such as the 'truth-plus-error', 'indistinguishable', or more recently 'replicate Earth' paradigm. Using a definition of model dependence based on error covariance within the replicate Earth paradigm, this presentation will show that accounting for dependence in surface air temperature gives cooler projections in CMIP5 - by as much as 20% globally in some RCPs - although results differ significantly for each RCP, especially regionally. The fact that the change afforded by accounting for dependence across different RCPs is different is not an inconsistent result. Different numbers of submissions to each RCP by different modelling groups mean that differences in projections from different RCPs are not entirely about RCP forcing conditions - they also reflect different sampling strategies.

Effect of air gap on apparent temperature of body wearing various sizes of T-shirt

NASA Astrophysics Data System (ADS)

Takatera, M.; Uchiyama, E.; Zhu, C.; Kim, KO; Ishizawa, H.

2017-10-01

We investigated the effect of air gap on the apparent temperature. Using the developed thermocouple fabric and a thermal manikin, we measured temperature distribution of the measuring garments due to the change of T-shirt sizes. We were able to measure the apparent temperature distribution at points near a body while wearing different sizes of T-shirts. It was observed that the temperature distribution depending on different air gap between clothing and body. The apparent temperature depends on garment size and place. The effect of air gap on apparent temperature of body was experimentally confirmed.

Stability of deep features across CT scanners and field of view using a physical phantom

NASA Astrophysics Data System (ADS)

Paul, Rahul; Shafiq-ul-Hassan, Muhammad; Moros, Eduardo G.; Gillies, Robert J.; Hall, Lawrence O.; Goldgof, Dmitry B.

2018-02-01

Radiomics is the process of analyzing radiological images by extracting quantitative features for monitoring and diagnosis of various cancers. Analyzing images acquired from different medical centers is confounded by many choices in acquisition, reconstruction parameters and differences among device manufacturers. Consequently, scanning the same patient or phantom using various acquisition/reconstruction parameters as well as different scanners may result in different feature values. To further evaluate this issue, in this study, CT images from a physical radiomic phantom were used. Recent studies showed that some quantitative features were dependent on voxel size and that this dependency could be reduced or removed by the appropriate normalization factor. Deep features extracted from a convolutional neural network, may also provide additional features for image analysis. Using a transfer learning approach, we obtained deep features from three convolutional neural networks pre-trained on color camera images. An we examination of the dependency of deep features on image pixel size was done. We found that some deep features were pixel size dependent, and to remove this dependency we proposed two effective normalization approaches. For analyzing the effects of normalization, a threshold has been used based on the calculated standard deviation and average distance from a best fit horizontal line among the features' underlying pixel size before and after normalization. The inter and intra scanner dependency of deep features has also been evaluated.

Steric effects on the primary isotope dependence of secondary kinetic isotope effects in hydride transfer reactions in solution: caused by the isotopically different tunneling ready state conformations?

PubMed

Maharjan, Binita; Raghibi Boroujeni, Mahdi; Lefton, Jonathan; White, Ormacinda R; Razzaghi, Mortezaali; Hammann, Blake A; Derakhshani-Molayousefi, Mortaza; Eilers, James E; Lu, Yun

2015-05-27

The observed 1° isotope effect on 2° KIEs in H-transfer reactions has recently been explained on the basis of a H-tunneling mechanism that uses the concept that the tunneling of a heavier isotope requires a shorter donor-acceptor distance (DAD) than that of a lighter isotope. The shorter DAD in D-tunneling, as compared to H-tunneling, could bring about significant spatial crowding effect that stiffens the 2° H/D vibrations, thus decreasing the 2° KIE. This leads to a new physical organic research direction that examines how structure affects the 1° isotope dependence of 2° KIEs and how this dependence provides information about the structure of the tunneling ready states (TRSs). The hypothesis is that H- and D-tunneling have TRS structures which have different DADs, and pronounced 1° isotope effect on 2° KIEs should be observed in tunneling systems that are sterically hindered. This paper investigates the hypothesis by determining the 1° isotope effect on α- and β-2° KIEs for hydride transfer reactions from various hydride donors to different carbocationic hydride acceptors in solution. The systems were designed to include the interactions of the steric groups and the targeted 2° H/D's in the TRSs. The results substantiate our hypothesis, and they are not consistent with the traditional model of H-tunneling and 1°/2° H coupled motions that has been widely used to explain the 1° isotope dependence of 2° KIEs in the enzyme-catalyzed H-transfer reactions. The behaviors of the 1° isotope dependence of 2° KIEs in solution are compared to those with alcohol dehydrogenases, and sources of the observed "puzzling" 2° KIE behaviors in these enzymes are discussed using the concept of the isotopically different TRS conformations.

Influence of compulsivity of drug abuse on dopaminergic modulation of attentional bias in stimulant dependence.

PubMed

Ersche, Karen D; Bullmore, Edward T; Craig, Kevin J; Shabbir, Shaila S; Abbott, Sanja; Müller, Ulrich; Ooi, Cinly; Suckling, John; Barnes, Anna; Sahakian, Barbara J; Merlo-Pich, Emilio V; Robbins, Trevor W

2010-06-01

There are no effective pharmacotherapies for stimulant dependence but there are many plausible targets for development of novel therapeutics. We hypothesized that dopamine-related targets are relevant for treatment of stimulant dependence, and there will likely be individual differences in response to dopaminergic challenges. To measure behavioral and brain functional markers of drug-related attentional bias in stimulant-dependent individuals studied repeatedly after short-term dosing with dopamine D(2)/D(3) receptor antagonist and agonist challenges. Randomized, double-blind, placebo-controlled, parallel-groups, crossover design using pharmacological functional magnetic resonance imaging. Clinical research unit (GlaxoSmithKline) and local community in Cambridge, England. Stimulant-dependent individuals (n = 18) and healthy volunteers (n = 18). Amisulpride (400 mg), pramipexole dihydrochloride (0.5 mg), or placebo were administered in counterbalanced order at each of 3 repeated testing sessions. Attentional bias for stimulant-related words was measured during functional magnetic resonance imaging by a drug-word Stroop paradigm; trait impulsivity and compulsivity of dependence were assessed at baseline by questionnaire. Drug users demonstrated significant attentional bias for drug-related words, which was correlated with greater activation of the left prefrontal and right cerebellar cortex. Attentional bias was greater in people with highly compulsive patterns of stimulant abuse; the effects of dopaminergic challenges on attentional interference and related frontocerebellar activation were different between high- and low-compulsivity subgroups. Greater attentional bias for and greater prefrontal activation by stimulant-related words constitute a candidate neurocognitive marker for dependence. Individual differences in compulsivity of stimulant dependence had significant effects on attentional bias, its brain functional representation, and its short-term modulation by dopaminergic challenges.

Influence of Compulsivity of Drug Abuse on Dopaminergic Modulation of Attentional Bias in Stimulant Dependence

PubMed Central

Ersche, Karen D.; Bullmore, Edward T.; Craig, Kevin J.; Shabbir, Shaila S.; Abbott, Sanja; Müller, Ulrich; Ooi, Cinly; Suckling, John; Barnes, Anna; Sahakian, Barbara J.; Merlo-Pich, Emilio V.; Robbins, Trevor W.

2013-01-01

Context There are no effective pharmacotherapies for stimulant dependence but there are many plausible targets for development of novel therapeutics. We hypothesized that dopamine-related targets are relevant for treatment of stimulant dependence, and there will likely be individual differences in response to dopaminergic challenges. Objective To measure behavioral and brain functional markers of drug-related attentional bias in stimulant-dependent individuals studied repeatedly after short-term dosing with dopamine D2/D3 receptor antagonist and agonist challenges. Design Randomized, double-blind, placebo-controlled, parallel-groups, crossover design using pharmacological functional magnetic resonance imaging. Setting Clinical research unit (GlaxoSmithKline) and local community in Cambridge, England. Participants Stimulant-dependent individuals (n=18) and healthy volunteers (n=18). Interventions Amisulpride (400 mg), pramipexole dihydrochloride (0.5 mg), or placebo were administered in counterbalanced order at each of 3 repeated testing sessions. Main Outcome Measures Attentional bias for stimulant-related words was measured during functional magnetic resonance imaging by a drug-word Stroop paradigm; trait impulsivity and compulsivity of dependence were assessed at baseline by questionnaire. Results Drug users demonstrated significant attentional bias for drug-related words, which was correlated with greater activation of the left prefrontal and right cerebellar cortex. Attentional bias was greater in people with highly compulsive patterns of stimulant abuse; the effects of dopaminergic challenges on attentional interference and related frontocerebellar activation were different between high- and low-compulsivity subgroups. Conclusions Greater attentional bias for and greater prefrontal activation by stimulant-related words constitute a candidate neurocognitive marker for dependence. Individual differences in compulsivity of stimulant dependence had significant effects on attentional bias, its brain functional representation, and its short-term modulation by dopaminergic challenges. PMID:20530013

Influence of mom and dad: quantitative genetic models for maternal effects and genomic imprinting.

PubMed

Santure, Anna W; Spencer, Hamish G

2006-08-01

The expression of an imprinted gene is dependent on the sex of the parent it was inherited from, and as a result reciprocal heterozygotes may display different phenotypes. In contrast, maternal genetic terms arise when the phenotype of an offspring is influenced by the phenotype of its mother beyond the direct inheritance of alleles. Both maternal effects and imprinting may contribute to resemblance between offspring of the same mother. We demonstrate that two standard quantitative genetic models for deriving breeding values, population variances and covariances between relatives, are not equivalent when maternal genetic effects and imprinting are acting. Maternal and imprinting effects introduce both sex-dependent and generation-dependent effects that result in differences in the way additive and dominance effects are defined for the two approaches. We use a simple example to demonstrate that both imprinting and maternal genetic effects add extra terms to covariances between relatives and that model misspecification may over- or underestimate true covariances or lead to extremely variable parameter estimation. Thus, an understanding of various forms of parental effects is essential in correctly estimating quantitative genetic variance components.

Detailed validation of the bidirectional effect in various Case 1 waters for application to ocean color imagery

NASA Astrophysics Data System (ADS)

Voss, K. J.; Morel, A.; Antoine, D.

2007-09-01

The radiance viewed from the ocean depends on the illumination and viewing geometry along with the water properties, and this variation is called the bidirectional effect. This bidirectional effect depends on the inherent optical properties of the water, including the volume scattering function, and is important when comparing data from different satellite sensors. The current model of f/Q, which contains the bidirectional effect, by Morel et al. (2002) depends on modeled, not measured, water parameters, thus must be carefully validated. In this paper we combined upwelling radiance distribution data from several cruises, in varied water types and with a wide range of solar zenith angles. We compared modeled and measured Lview/Lnadir and found that the average difference between the model and data was less than 0.01, while the RMS difference between the model and data was on the order of 0.02-0.03. This is well within the statistical noise of the data, which was on the order of 0.04-0.05, due to environmental noise sources such as wave focusing.

Analysis of dependent scattering mechanism in hard-sphere Yukawa random media

NASA Astrophysics Data System (ADS)

Wang, B. X.; Zhao, C. Y.

2018-06-01

The structural correlations in the microscopic structures of random media can induce the dependent scattering mechanism and thus influence the optical scattering properties. Based on our recent theory on the dependent scattering mechanism in random media composed of discrete dipolar scatterers [B. X. Wang and C. Y. Zhao, Phys. Rev. A 97, 023836 (2018)], in this paper, we study the hard-sphere Yukawa random media, in order to further elucidate the role of structural correlations in the dependent scattering mechanism and hence optical scattering properties. Here, we consider charged colloidal suspensions, whose effective pair interaction between colloids is described by a screened Coulomb (Yukawa) potential. By means of adding salt ions, the pair interaction between the charged particles can be flexibly tailored and therefore the structural correlations are modified. It is shown that this strategy can affect the optical properties significantly. For colloidal TiO2 suspensions, the modification of electric and magnetic dipole excitations induced by the structural correlations can substantially influence the optical scattering properties, in addition to the far-field interference effect described by the structure factor. However, this modification is only slightly altered by different salt concentrations and is mainly because of the packing-density-dependent screening effect. On the other hand, for low refractive index colloidal polystyrene suspensions, the dependent scattering mechanism mainly involves the far-field interference effect, and the effective exciting field amplitude for the electric dipole almost remains unchanged under different structural correlations. The present study has profound implications for understanding the role of structural correlations in the dependent scattering mechanism.

The relationship between oxidative stress and exercise.

PubMed

Finkler, Maya; Lichtenberg, Dov; Pinchuk, Ilya

2014-02-01

Physical exercise has many benefits, but it might also have a negative impact on the body, depending on the training level, length of workout, gender, age and fitness. The negative effects of physical exercise are commonly attributed to an imbalance between the levels of antioxidants (both low molecular weight antioxidants and antioxidant enzymes) and reactive oxygen and nitrogen species due to excessive production of free radicals during physical exercise. In this critical review, we look for answers for three specific questions regarding the interrelationship between physical exercise and oxidative stress (OS), namely, (i) the dependence of the steady-state level of OS on fitness, (ii) the effect of intensive exercise on the OS and (iii) the dependence of the effect of the intense exercise on the individual fitness. All these questions have been raised, investigated and answered, but the answers given on the basis of different studies are different. In the present review, we try to explain the reason(s) for the inconsistencies between the conclusions of different investigations, commonly based on the concentrations of specific biomarkers in body fluids. We think that most of the inconsistencies can be attributed to the difference between the criteria of the ill-defined term denoted OS, the methods used to test them and in some cases, between the qualities of the applied assays. On the basis of our interpretation of the differences between different criteria of OS, we consider possible answers to three well-defined questions. Possible partial answers are given, all of which lend strong support to the conclusion that the network responsible for homeostasis of the redox status is very effective. However, much more data are required to address the association between exercise and OS and its dependence on various relevant factors.

Conflict between Place and Response Navigation Strategies: Effects on Vicarious Trial and Error (VTE) Behaviors

ERIC Educational Resources Information Center

Schmidt, Brandy; Papale, Andrew; Redish, A. David; Markus, Etan J.

2013-01-01

Navigation can be accomplished through multiple decision-making strategies, using different information-processing computations. A well-studied dichotomy in these decision-making strategies compares hippocampal-dependent "place" and dorsal-lateral striatal dependent "response" strategies. A place strategy depends on the ability to flexibly respond…

38 CFR 3.650 - Rate for additional dependent.

Code of Federal Regulations, 2014 CFR

2014-07-01

... be effective from the date of potential entitlement of the additional dependent. (2) Where benefits... for periods prior to the date the full rate is awarded shall be the difference between the rate...

38 CFR 3.650 - Rate for additional dependent.

Code of Federal Regulations, 2013 CFR

2013-07-01

... be effective from the date of potential entitlement of the additional dependent. (2) Where benefits... for periods prior to the date the full rate is awarded shall be the difference between the rate...

38 CFR 3.650 - Rate for additional dependent.

Code of Federal Regulations, 2012 CFR

2012-07-01

... be effective from the date of potential entitlement of the additional dependent. (2) Where benefits... for periods prior to the date the full rate is awarded shall be the difference between the rate...

38 CFR 3.650 - Rate for additional dependent.

Code of Federal Regulations, 2010 CFR

2010-07-01

... be effective from the date of potential entitlement of the additional dependent. (2) Where benefits... for periods prior to the date the full rate is awarded shall be the difference between the rate...

38 CFR 3.650 - Rate for additional dependent.

Code of Federal Regulations, 2011 CFR

2011-07-01

... be effective from the date of potential entitlement of the additional dependent. (2) Where benefits... for periods prior to the date the full rate is awarded shall be the difference between the rate...

Sex Differences in Gray Matter Changes and Brain-Behavior Relationships in Patients with Stimulant Dependence.

PubMed

Regner, Michael F; Dalwani, Manish; Yamamoto, Dorothy; Perry, Robert I; Sakai, Joseph T; Honce, Justin M; Tanabe, Jody

2015-12-01

To investigate whether sex modulates the effects of stimulant dependence on gray matter volume (GMV) in patients who have achieved long-term abstinence and to characterize how sex modulates GMV according to specific behavioral measures, such as dependence symptom count, behavioral approach, and impulsivity. Colorado Multiple Institutional Review Board approval and informed consent were obtained. In this prospective parallel group study, 127 age- and sex-matched participants (68 control subjects [28 women, 40 men] and 59 patients with stimulant dependence [28 women, 31 men]) underwent T1-weighted spoiled gradient-echo inversion recovery magnetic resonance imaging of the brain at 3 T. Images were segmented by using voxel-based morphometric software. After adjustment for age, education, and head size, the effects of group according to sex on GMV and main effects were analyzed throughout the whole brain by using an analysis of covariance family-wise cluster corrected for multiple comparisons, with a threshold P value of less than .05. Dependence symptom count and behavioral measurements were correlated with GMV in the whole brain and in five a priori regions of interest. The effects of group according to sex on GMV were significant in numerous regions (P < .001). Compared with female control subjects, women with stimulant dependence had significantly lower GMV in widespread brain regions (P < .001). There were no significant differences in GMV between male control subjects and men with stimulant dependence (P = .625). Dependence symptom count negatively correlated with GMV in the nucleus accumbens in women (left: r = -0.364, P = .047; right: r = -0.407, P = .031) but not in men (left: r = -0.063, P = .737; right: r = -0.174, P = .349). Behavioral approach (P = .002) and impulsivity (P = .013) correlated negatively with frontal and temporal GMV changes in women with stimulant dependence but not in the other groups. Vast changes in GMV were observed in women with stimulant dependence after prolonged abstinence, but were not observed in men. Sexual dimorphism in drug-related neuroanatomic changes and brain-behavior relationships may be mechanisms underlying the difference in clinical profiles of addiction between women and men.

The Effect of Sex-Dependent Norms on Aggregated Reading and Mathematics Test Scores.

ERIC Educational Resources Information Center

Gramenz, Gary W.; And Others

1986-01-01

Differences between school reading and mathematics means, rank orderings, and change scores obtained from total-group and sex-dependent norms were examined for students in grades 2 through 9 in a Florida school district. A preliminary study investigated sex-related differences between verbal and quantitative performance of boys and girls on seven…

Reinforcer magnitude and rate dependency: evaluation of resistance-to-change mechanisms.

PubMed

Pinkston, Jonathan W; Ginsburg, Brett C; Lamb, Richard J

2014-10-01

Under many circumstances, reinforcer magnitude appears to modulate the rate-dependent effects of drugs such that when schedules arrange for relatively larger reinforcer magnitudes rate dependency is attenuated compared with behavior maintained by smaller magnitudes. The current literature on resistance to change suggests that increased reinforcer density strengthens operant behavior, and such strengthening effects appear to extend to the temporal control of behavior. As rate dependency may be understood as a loss of temporal control, the effects of reinforcer magnitude on rate dependency may be due to increased resistance to disruption of temporally controlled behavior. In the present experiments, pigeons earned different magnitudes of grain during signaled components of a multiple FI schedule. Three drugs, clonidine, haloperidol, and morphine, were examined. All three decreased overall rates of key pecking; however, only the effects of clonidine were attenuated as reinforcer magnitude increased. An analysis of within-interval performance found rate-dependent effects for clonidine and morphine; however, these effects were not modulated by reinforcer magnitude. In addition, we included prefeeding and extinction conditions, standard tests used to measure resistance to change. In general, rate-decreasing effects of prefeeding and extinction were attenuated by increasing reinforcer magnitudes. Rate-dependent analyses of prefeeding showed rate-dependency following those tests, but in no case were these effects modulated by reinforcer magnitude. The results suggest that a resistance-to-change interpretation of the effects of reinforcer magnitude on rate dependency is not viable.

Different methods to analyze stepped wedge trial designs revealed different aspects of intervention effects.

PubMed

Twisk, J W R; Hoogendijk, E O; Zwijsen, S A; de Boer, M R

2016-04-01

Within epidemiology, a stepped wedge trial design (i.e., a one-way crossover trial in which several arms start the intervention at different time points) is increasingly popular as an alternative to a classical cluster randomized controlled trial. Despite this increasing popularity, there is a huge variation in the methods used to analyze data from a stepped wedge trial design. Four linear mixed models were used to analyze data from a stepped wedge trial design on two example data sets. The four methods were chosen because they have been (frequently) used in practice. Method 1 compares all the intervention measurements with the control measurements. Method 2 treats the intervention variable as a time-independent categorical variable comparing the different arms with each other. In method 3, the intervention variable is a time-dependent categorical variable comparing groups with different number of intervention measurements, whereas in method 4, the changes in the outcome variable between subsequent measurements are analyzed. Regarding the results in the first example data set, methods 1 and 3 showed a strong positive intervention effect, which disappeared after adjusting for time. Method 2 showed an inverse intervention effect, whereas method 4 did not show a significant effect at all. In the second example data set, the results were the opposite. Both methods 2 and 4 showed significant intervention effects, whereas the other two methods did not. For method 4, the intervention effect attenuated after adjustment for time. Different methods to analyze data from a stepped wedge trial design reveal different aspects of a possible intervention effect. The choice of a method partly depends on the type of the intervention and the possible time-dependent effect of the intervention. Furthermore, it is advised to combine the results of the different methods to obtain an interpretable overall result. Copyright © 2016 Elsevier Inc. All rights reserved.

The Role of the Situation Model for Rereading Benefits in Korean-German Bilinguals.

PubMed

Shin, Hong Im; Wippich, Werner

2016-10-01

This study examines whether rereading effects transfer across two different languages at the passage level. Fluent Korean-German bilinguals read passages twice either in the same language or a different language, and passages shared either words or situations. The dependent measure was the overall reading time for the second passage reading. Repetition effects were found only for passages in which situation models were preserved, although the translation altered the surface form and the textbase, demonstrating that the situation model plays an important role in bilingual repetition effects and that the context-dependent model Raney (Psychon Bull Rev 10:15-28, 2003) provides a theoretically meaningful guide for explaining rereading effects.

In Vitro and In Vivo Short-Term Pulmonary Toxicity of Differently Sized Colloidal Amorphous SiO2

PubMed Central

Wiemann, Martin; Sauer, Ursula G.; Vennemann, Antje; Bäcker, Sandra; Keller, Johannes-Georg; Ma-Hock, Lan; Wohlleben, Wendel; Landsiedel, Robert

2018-01-01

In vitro prediction of inflammatory lung effects of well-dispersed nanomaterials is challenging. Here, the in vitro effects of four colloidal amorphous SiO2 nanomaterials that differed only by their primary particle size (9, 15, 30, and 55 nm) were analyzed using the rat NR8383 alveolar macrophage (AM) assay. Data were compared to effects of single doses of 15 nm and 55 nm SiO2 intratracheally instilled in rat lungs. In vitro, all four elicited the release of concentration-dependent lactate dehydrogenase, β-glucuronidase, and tumor necrosis factor alpha, and the two smaller materials also released H2O2. All effects were size-dependent. Since the colloidal SiO2 remained well-dispersed in serum-free in vitro conditions, effective particle concentrations reaching the cells were estimated using different models. Evaluating the effective concentration–based in vitro effects using the Decision-making framework for the grouping and testing of nanomaterials, all four nanomaterials were assigned as “active.” This assignment and the size dependency of effects were consistent with the outcomes of intratracheal instillation studies and available short-term rat inhalation data for 15 nm SiO2. The study confirms the applicability of the NR8383 AM assay to assessing colloidal SiO2 but underlines the need to estimate and consider the effective concentration of such well-dispersed test materials. PMID:29534009

Internal state variable plasticity-damage modeling of AISI 4140 steel including microstructure-property relations: temperature and strain rate effects

NASA Astrophysics Data System (ADS)

Nacif el Alaoui, Reda

Mechanical structure-property relations have been quantified for AISI 4140 steel. under different strain rates and temperatures. The structure-property relations were used. to calibrate a microstructure-based internal state variable plasticity-damage model for. monotonic tension, compression and torsion plasticity, as well as damage evolution. Strong stress state and temperature dependences were observed for the AISI 4140 steel. Tension tests on three different notched Bridgman specimens were undertaken to study. the damage-triaxiality dependence for model validation purposes. Fracture surface. analysis was performed using Scanning Electron Microscopy (SEM) to quantify the void. nucleation and void sizes in the different specimens. The stress-strain behavior exhibited. a fairly large applied stress state (tension, compression dependence, and torsion), a. moderate temperature dependence, and a relatively small strain rate dependence.

Measuring aging rates of mice subjected to caloric restriction and genetic disruption of growth hormone signaling

PubMed Central

Koopman, Jacob J.E.; van Heemst, Diana; van Bodegom, David; Bonkowski, Michael S.; Sun, Liou Y.; Bartke, Andrzej

2016-01-01

Caloric restriction and genetic disruption of growth hormone signaling have been shown to counteract aging in mice. The effects of these interventions on aging are examined through age-dependent survival or through the increase in age-dependent mortality rates on a logarithmic scale fitted to the Gompertz model. However, these methods have limitations that impede a fully comprehensive disclosure of these effects. Here we examine the effects of these interventions on murine aging through the increase in age-dependent mortality rates on a linear scale without fitting them to a model like the Gompertz model. Whereas these interventions negligibly and non-consistently affected the aging rates when examined through the age-dependent mortality rates on a logarithmic scale, they caused the aging rates to increase at higher ages and to higher levels when examined through the age-dependent mortality rates on a linear scale. These results add to the debate whether these interventions postpone or slow aging and to the understanding of the mechanisms by which they affect aging. Since different methods yield different results, it is worthwhile to compare their results in future research to obtain further insights into the effects of dietary, genetic, and other interventions on the aging of mice and other species. PMID:26959761

Measuring aging rates of mice subjected to caloric restriction and genetic disruption of growth hormone signaling.

PubMed

Koopman, Jacob J E; van Heemst, Diana; van Bodegom, David; Bonkowski, Michael S; Sun, Liou Y; Bartke, Andrzej

2016-03-01

Caloric restriction and genetic disruption of growth hormone signaling have been shown to counteract aging in mice. The effects of these interventions on aging are examined through age-dependent survival or through the increase in age-dependent mortality rates on a logarithmic scale fitted to the Gompertz model. However, these methods have limitations that impede a fully comprehensive disclosure of these effects. Here we examine the effects of these interventions on murine aging through the increase in age-dependent mortality rates on a linear scale without fitting them to a model like the Gompertz model. Whereas these interventions negligibly and non-consistently affected the aging rates when examined through the age-dependent mortality rates on a logarithmic scale, they caused the aging rates to increase at higher ages and to higher levels when examined through the age-dependent mortality rates on a linear scale. These results add to the debate whether these interventions postpone or slow aging and to the understanding of the mechanisms by which they affect aging. Since different methods yield different results, it is worthwhile to compare their results in future research to obtain further insights into the effects of dietary, genetic, and other interventions on the aging of mice and other species.

[Psychological time, definition and challenges].

PubMed

Droit-Volet, Sylvie

2012-10-01

Psychological time comprises different forms of time. Each form of time corresponds to different psychological mechanisms. The human being is subject to distortions of time under the effect of emotions. The effectiveness of social interaction depends on our aptitude to synchronise ourselves with others.

Disentangling density-dependent dynamics using full annual cycle models and Bayesian model weight updating

USGS Publications Warehouse

Robinson, Orin J.; McGowan, Conor P.; Devers, Patrick K.

2017-01-01

Density dependence regulates populations of many species across all taxonomic groups. Understanding density dependence is vital for predicting the effects of climate, habitat loss and/or management actions on wild populations. Migratory species likely experience seasonal changes in the relative influence of density dependence on population processes such as survival and recruitment throughout the annual cycle. These effects must be accounted for when characterizing migratory populations via population models.To evaluate effects of density on seasonal survival and recruitment of a migratory species, we used an existing full annual cycle model framework for American black ducks Anas rubripes, and tested different density effects (including no effects) on survival and recruitment. We then used a Bayesian model weight updating routine to determine which population model best fit observed breeding population survey data between 1990 and 2014.The models that best fit the survey data suggested that survival and recruitment were affected by density dependence and that density effects were stronger on adult survival during the breeding season than during the non-breeding season.Analysis also suggests that regulation of survival and recruitment by density varied over time. Our results showed that different characterizations of density regulations changed every 8–12 years (three times in the 25-year period) for our population.Synthesis and applications. Using a full annual cycle, modelling framework and model weighting routine will be helpful in evaluating density dependence for migratory species in both the short and long term. We used this method to disentangle the seasonal effects of density on the continental American black duck population which will allow managers to better evaluate the effects of habitat loss and potential habitat management actions throughout the annual cycle. The method here may allow researchers to hone in on the proper form and/or strength of density dependence for use in models for conservation recommendations.

Polarization-dependent plasmonic photocurrents in two-dimensional electron systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Popov, V. V., E-mail: popov-slava@yahoo.co.uk; Saratov State University, Saratov 410012; Saratov Scientific Center of the Russian Academy of Sciences, Saratov 410028

2016-06-27

Plasmonic polarization dependent photocurrents in a homogeneous two-dimensional electron system are studied. Those effects are completely different from the photon drag and electronic photogalvanic effects as well as from the plasmonic ratchet effect in a density modulated two-dimensional electron system. Linear and helicity-dependent contributions to the photocurrent are found. The linear contribution can be interpreted as caused by the longitudinal and transverse plasmon drag effect. The helicity-dependent contribution originates from the non-linear electron convection and changes its sign with reversing the plasmonic field helicity. It is shown that the helicity-dependent component of the photocurrent can exceed the linear one bymore » several orders of magnitude in high-mobility two-dimensional electron systems. The results open possibilities for all-electronic detection of the radiation polarization states by exciting the plasmonic photocurrents in two-dimensional electron systems.« less

Effect of prior performance on subsequent performance evaluation by field independent-dependent raters.

PubMed

Sisco, Howard; Leventhal, Gloria

2007-12-01

The importance of accurate performance appraisals is central to many aspects of personnel activities in organizations. This study examined threats due to past performance to accuracy of evaluation of subsequent performance by raters differing in scores on field dependence. 162 college students were classified as Field-dependent (n = 81) or Field-independent (n = 81), using a median split on the Group Embedded Figures Test. Past performance (a lecture) was good or poor, presented directly via a videotape or indirectly via a written evaluation to the Field-independent or Field-dependent groups. Analysis indicated the hypothesized contrast effect (ratings in the opposite direction from that of prior ratings) in the Direct condition and an unexpected, albeit smaller, contrast effect in the Indirect condition. There were also differential effects of performance, presentation, and field dependency on rating of lecturer's style and ability.

Impact of an Individual Mandate and Other Health Reforms on Dependent Coverage for Adolescents and Young Adults.

PubMed

Wisk, Lauren E; Finkelstein, Jonathan A; Toomey, Sara L; Sawicki, Gregory S; Schuster, Mark A; Galbraith, Alison A

2018-06-01

To determine the effect of state-level dependent coverage expansion (DCE) with and without other state health reforms on exit from dependent coverage for adolescents and young adults (AYA). Administrative longitudinal data for 131,542 privately insured AYA in Massachusetts (DCE with other reforms) versus Maine and New Hampshire (DCE without other reforms) across three periods: prereform (1/00-12/06), poststate reform (1/07-9/10), and postfederal reform (10/10-12/12). A difference-in-differences estimator was used to determine the rate of exit from dependent coverage, age at exit from dependent coverage, and re-uptake of dependent coverage among AYA in states with comprehensive reforms versus DCE only. Implementation of DCE with other reforms was significantly associated with a 23 percent reduction in exit from dependent coverage among AYA compared to the reduction observed for DCE alone. Additionally, comprehensive reforms were associated with over two additional years of dependent coverage for the average AYA and a 33 percent increase in the odds of regaining dependent coverage after a prior loss. Findings suggest that an individual mandate and other reforms may enhance the effect of DCE in preventing loss of coverage among AYA. © Health Research and Educational Trust.

Reggi-Leduc and Maggi-Reggi-Leduc effects in conducting films with an anisotropic dispersion law

NASA Astrophysics Data System (ADS)

Askerov, B. M.; Guseinov, G. I.; Kuliev, B. I.; Figarova, S. R.

1989-06-01

The influence of the spectrum and bulk scattering anisotropies on the Reggi-Leduc and Maggi-Reggi-Leduc effects is investigated in semiconducting films of the electronic silicon type under classical dimensional effect conditions. It is shown that in contrast to a massive specimen these effects depend not only on a single parameter, the ratio between the anisotropy coefficients of the effective mass and the relaxation time but also on each of them separately, which permit their direct determination. It is also established that the Reggi-Leduc coefficient depends differently on the film thickness, depending on the relationship between the electron and phonon parts of the crystal heat conductivity.

Field Dependence-Independence Cognitive Style and Academic Achievement: A Review of Research and Theory.

ERIC Educational Resources Information Center

Tinajero, Carolina; Paramo, M. Fernanda

1998-01-01

Reviews research into the possible effects of field dependence/independence on achievement at school. Finds that field-independent subjects perform better than field-dependent subjects, whether in a specific discipline or across all subjects. Discusses possible explanations for this difference in performance. Includes a chart summarizing the…

Institutional Regimes and Induced Dependency in Homes for the Aged.

ERIC Educational Resources Information Center

Booth, Tim

1986-01-01

Reports effects of institutional regimes on levels of dependency among residents of public homes for the elderly in England. Differences in management practices and caring routines did not affect the creation or reduction of dependency among residents. Questions the rationale that informs some current notions of good practice in residential work.…

Nuclear symmetry energy in terms of single-nucleon potential and its effect on the proton fraction of β-stable npeμ matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sahoo, Babita, E-mail: patra-babita@rediffmail.com; Chakraborty, Suparna, E-mail: banerjee.suparna@hotmail.com; Sahoo, Sukadev, E-mail: sukadevsahoo@yahoo.com

2016-01-15

Momentum and density dependence of single-nucleon potential u{sub τ} (k, ρ, β) is analyzed using a density dependent finite range effective interaction of the Yukawa form. Depending on the choice of the strength parameters of exchange interaction, two different trends of the momentum dependence of nuclear symmetry potential are noticed which lead to two opposite types of neutron and proton effective mass splitting. The 2nd-order and 4th-order symmetry energy of isospin asymmetric nuclear matter are expressed analytically in terms of the single-nucleon potential. Two distinct behavior of the density dependence of 2nd-order and 4th-order symmetry energy are observed depending onmore » neutron and proton effective mass splitting. It is also found that the 4th-order symmetry energy has a significant contribution towards the proton fraction of β-stable npeμ matter at high densities.« less

Effect of dexamethasone on expression of glucocorticoid receptor in human monocyte cell line THP-1.

PubMed

Li, Bo; Bai, Xiangjun; Wanh, Haiping

2006-01-01

The effect of dexamethasone with different concentrations and different stimulating periods on the expression of glucocorticoid receptors (GRalpha, GRbeta) protein was investigated in human monocyte cell line THP-1. The cultured human monocyte line THP-1 cells were stimulated by dexamethasone with different concentrations and different periods. The expression of GRalpha and GRbeta protein was detected by Western blotting. The results showed that the expression of GRalpha and GRbeta was detected in the THP-1 cells. The quantity of GRalpha expression was reduced by dexamethasone under the same concentration with the prolongation of the stimulating periods. The quantity of GRbeta expression was increased by dexamethasone treatment in a time- and dose-dependent manner. It was concluded that dexamethasone stimulation time-dependently reduced the GRalpha expression in THP-1 cells. Dexamethasone stimulation time- and dose-dependently increased the GRbeta expression in THP-1 cells. The expression of GRalpha and GRbeta was regulated by glucocorticoid.

Drag reduction in homogeneous turbulence by scale-dependent effective viscosity.

PubMed

Benzi, Roberto; Ching, Emily S C; Procaccia, Itamar

2004-08-01

We demonstrate, by using suitable shell models, that drag reduction in homogeneous turbulence is usefully discussed in terms of a scale-dependent effective viscosity. The essence of the phenomenon of drag reduction found in models that couple the velocity field to the polymers can be recaptured by an "equivalent" equation of motion for the velocity field alone, with a judiciously chosen scale-dependent effective viscosity that succinctly summarizes the important aspects of the interaction between the velocity and the polymer fields. Finally, we clarify the differences between drag reduction in homogeneous and in wall bounded flows.

Noise exposure-response relationships established from repeated binary observations: Modeling approaches and applications.

PubMed

Schäffer, Beat; Pieren, Reto; Mendolia, Franco; Basner, Mathias; Brink, Mark

2017-05-01

Noise exposure-response relationships are used to estimate the effects of noise on individuals or a population. Such relationships may be derived from independent or repeated binary observations, and modeled by different statistical methods. Depending on the method by which they were established, their application in population risk assessment or estimation of individual responses may yield different results, i.e., predict "weaker" or "stronger" effects. As far as the present body of literature on noise effect studies is concerned, however, the underlying statistical methodology to establish exposure-response relationships has not always been paid sufficient attention. This paper gives an overview on two statistical approaches (subject-specific and population-averaged logistic regression analysis) to establish noise exposure-response relationships from repeated binary observations, and their appropriate applications. The considerations are illustrated with data from three noise effect studies, estimating also the magnitude of differences in results when applying exposure-response relationships derived from the two statistical approaches. Depending on the underlying data set and the probability range of the binary variable it covers, the two approaches yield similar to very different results. The adequate choice of a specific statistical approach and its application in subsequent studies, both depending on the research question, are therefore crucial.

Age-dependent and -independent changes in attention-deficit/hyperactivity disorder (ADHD) during spatial working memory performance.

PubMed

Bollmann, Steffen; Ghisleni, Carmen; Poil, Simon-Shlomo; Martin, Ernst; Ball, Juliane; Eich-Höchli, Dominique; Klaver, Peter; O'Gorman, Ruth L; Michels, Lars; Brandeis, Daniel

2017-06-01

Attention-deficit/hyperactivity disorder (ADHD) has been associated with spatial working memory as well as frontostriatal core deficits. However, it is still unclear how the link between these frontostriatal deficits and working memory function in ADHD differs in children and adults. This study examined spatial working memory in adults and children with ADHD, focussing on identifying regions demonstrating age-invariant or age-dependent abnormalities. We used functional magnetic resonance imaging to examine a group of 26 children and 35 adults to study load manipulated spatial working memory in patients and controls. In comparison to healthy controls, patients demonstrated reduced positive parietal and frontostriatal load effects, i.e., less increase in brain activity from low to high load, despite similar task performance. In addition, younger patients showed negative load effects, i.e., a decrease in brain activity from low to high load, in medial prefrontal regions. Load effect differences between ADHD and controls that differed between age groups were found predominantly in prefrontal regions. Age-invariant load effect differences occurred predominantly in frontostriatal regions. The age-dependent deviations support the role of prefrontal maturation and compensation in ADHD, while the age-invariant alterations observed in frontostriatal regions provide further evidence that these regions reflect a core pathophysiology in ADHD.

Antihypertensive properties of lactoferricin B-derived peptides.

PubMed

Ruiz-Giménez, Pedro; Ibáñez, Aida; Salom, Juan B; Marcos, Jose F; López-Díez, Jose Javier; Vallés, Salvador; Torregrosa, Germán; Alborch, Enrique; Manzanares, Paloma

2010-06-09

A set of eight lactoferricin B (LfcinB)-derived peptides was examined for inhibitory effects on angiotensin I-converting enzyme (ACE) activity and ACE-dependent vasoconstriction, and their hypotensive effect in spontaneously hypertensive rats (SHR). Peptides were derived from different elongations both at the C-terminal and N-terminal ends of the representative peptide LfcinB(20-25), which is known as the LfcinB antimicrobial core. All of the eight LfcinB-derived peptides showed in vitro inhibitory effects on ACE activity with different IC(50) values. Moreover, seven of them showed ex vivo inhibitory effects on ACE-dependent vasoconstriction. No clear correlation between in vitro and ex vivo inhibitory effects was found. Only LfcinB(20-25) and one of its fragments, F1, generated after a simulated gastrointestinal digestion, showed significant antihypertensive effects in SHR after oral administration. Remarkably, F1 did not show any effect on ACE-dependent vasoconstriction in contrast to the inhibitory effect showed by LfcinB(20-25). In conclusion, two LfcinB-derived peptides lower blood pressure and exhibit potential as orally effective antihypertensive compounds, yet a complete elucidation of the mechanism(s) involved deserves further ongoing research.

Serial dependence in the perception of attractiveness.

PubMed

Xia, Ye; Leib, Allison Yamanashi; Whitney, David

2016-12-01

The perception of attractiveness is essential for choices of food, object, and mate preference. Like perception of other visual features, perception of attractiveness is stable despite constant changes of image properties due to factors like occlusion, visual noise, and eye movements. Recent results demonstrate that perception of low-level stimulus features and even more complex attributes like human identity are biased towards recent percepts. This effect is often called serial dependence. Some recent studies have suggested that serial dependence also exists for perceived facial attractiveness, though there is also concern that the reported effects are due to response bias. Here we used an attractiveness-rating task to test the existence of serial dependence in perceived facial attractiveness. Our results demonstrate that perceived face attractiveness was pulled by the attractiveness level of facial images encountered up to 6 s prior. This effect was not due to response bias and did not rely on the previous motor response. This perceptual pull increased as the difference in attractiveness between previous and current stimuli increased. Our results reconcile previously conflicting findings and extend previous work, demonstrating that sequential dependence in perception operates across different levels of visual analysis, even at the highest levels of perceptual interpretation.

Responsiveness of the Care Dependency Scale for Rehabilitation (CDS-R).

PubMed

Eichhorn-Kissel, Juliane; Dassen, Theo; Lohrmann, Christa

2012-03-01

Around 10% of Western Europe's population suffer from a disability which can entail a decrease of independency and quality of life. However, the lives of these people can be improved by rehabilitative treatment and care. Changing the degree of dependency from dependent to independent is essential in rehabilitation, as is the assessment of these changes. To perform such kind of measurements, assessment instruments have to be responsive. In spite of this concern, responsiveness of assessment instruments is studied to a small extent only. This also applies to the Care Dependency Scale for Rehabilitation (CDS-R), a short assessment instrument measuring the care dependency of patients regarding physical and psychosocial aspects. In this longitudinal-study, the responsiveness of the CDS-R, in general and related to different disease-groups, should be determined. Therefore, a convenience sample of 1564 patients was assessed in an Austrian rehabilitation centre with the scale after admission and before discharge. Responsiveness was determined by descriptive analysis, calculation of effect-sizes and significance tests. Differences between admission and discharge occurred on a statistically significant level for patients who changed. Kazis' effect-sizes can be considered as of small/medium effect for patients who changed (0.24/0.49), and as of large effect according to Liang (0.86/1.46). Eta squared was 0.10/0.19 which can be interpreted as of moderate/large effect for patients who changed. Responsiveness-analyses related to different disease-groups showed constantly large effect-sizes for patients with musculoskeletal-disorders. These results indicate that the CDS-R can detect patient-changes over time and discriminate between patients who change under rehabilitation or not. These aspects argue for the responsiveness of the scale, wherefore the CDS-R seems to be appropriate for the assessment of treatment/health-care effectiveness and the evaluation of individual patient-changes. Nevertheless further research is recommended to confirm the level of responsiveness of the scale in general and for different disease-groups. © 2011 The Authors. Scandinavian Journal of Caring Sciences © 2011 Nordic College of Caring Science.

The effect of loading time on flexible pavement dynamic response: a finite element analysis

NASA Astrophysics Data System (ADS)

Yin, Hao; Solaimanian, Mansour; Kumar, Tanmay; Stoffels, Shelley

2007-12-01

Dynamic response of asphalt concrete (AC) pavements under moving load is a key component for accurate prediction of flexible pavement performance. The time and temperature dependency of AC materials calls for utilizing advanced material characterization and mechanistic theories, such as viscoelasticity and stress/strain analysis. In layered elastic analysis, as implemented in the new Mechanistic-Empirical Pavement Design Guide (MEPDG), the time dependency is accounted for by calculating the loading times at different AC layer depths. In this study, the time effect on pavement response was evaluated by means of the concept of “pseudo temperature.” With the pavement temperature measured from instrumented thermocouples, the time and temperature dependency of AC materials was integrated into one single factor, termed “effective temperature.” Via this effective temperature, pavement responses under a transient load were predicted through finite element analysis. In the finite element model, viscoelastic behavior of AC materials was characterized through relaxation moduli, while the layers with unbound granular material were assumed to be in an elastic mode. The analysis was conducted for two different AC mixtures in a simplified flexible pavement structure at two different seasons. Finite element analysis results reveal that the loading time has a more pronounced impact on pavement response in the summer for both asphalt types. The results indicate that for reasonable prediction of dynamic response in flexible pavements, the effect of the depth-dependent loading time on pavement temperature should be considered.

Uncertainty analysis in fault tree models with dependent basic events.

PubMed

Pedroni, Nicola; Zio, Enrico

2013-06-01

In general, two types of dependence need to be considered when estimating the probability of the top event (TE) of a fault tree (FT): "objective" dependence between the (random) occurrences of different basic events (BEs) in the FT and "state-of-knowledge" (epistemic) dependence between estimates of the epistemically uncertain probabilities of some BEs of the FT model. In this article, we study the effects on the TE probability of objective and epistemic dependences. The well-known Frèchet bounds and the distribution envelope determination (DEnv) method are used to model all kinds of (possibly unknown) objective and epistemic dependences, respectively. For exemplification, the analyses are carried out on a FT with six BEs. Results show that both types of dependence significantly affect the TE probability; however, the effects of epistemic dependence are likely to be overwhelmed by those of objective dependence (if present). © 2012 Society for Risk Analysis.

Pregabalin role in inhibition of morphine analgesic tolerance and physical dependency in rats.

PubMed

Hasanein, Parisa; Shakeri, Saeed

2014-11-05

Pregabalin is recently proposed as analgesic or adjuvant in pain management. While previous preclinical investigations have evaluated pregabalin-opioid interactions, the effect of pregabalin on opioid tolerance and dependency has not yet been studied. Here we evaluated the effects of different doses of pregabalin (50, 100 and 200mg/kg, s.c.) on morphine-induced tolerance and dependency in rats. Adult male Wistar rats were rendered tolerant to analgesic effect of morphine by injection of morphine (10mg/kg, s.c.) twice daily for 7 days. To develop morphine dependence, rats were given escalating doses of morphine. To determine the effect of pregabalin on the development of morphine tolerance and dependence, different doses of pregabalin were administrated before morphine. The tail-flick and naloxone precipitation withdrawal tests were used to evaluate the degree of tolerance and dependence, respectively. Chronic morphine-injected rats showed significant decrements in the percentage maximum possible effect (%MPE) of morphine on the days 5 and 7 (32.5%±3.5, 21.5%±4, respectively) compared to the first day (100%) which showed morphine tolerance. Pregabalin 200mg/kg completely prevented the development of morphine tolerance. In addition, concomitant treatment of morphine with pregabalin attenuated almost all of the naloxone-induced withdrawal signs which include weight loss, jumping, penis licking, teeth chattering, wet dog shakes, rearing, standing, sniffing, face grooming and paw tremor. These data show that pregabaline has a potential anti-tolerant/anti-dependence property against chronic usage of morphine. Therefore, pregabalin appears to be a promising candidate for the treatment of opioid addiction after confirming by future clinical studies. Copyright © 2014 Elsevier B.V. All rights reserved.

Gender Differences in the Effect of Tobacco Use on Brain Phosphocreatine Levels in Methamphetamine Dependent Subjects

PubMed Central

Sung, Young-Hoon; Yurgelun-Todd, Deborah A.; Kondo, Douglas G.; Shi, Xian-Feng; Lundberg, Kelly J.; Hellem, Tracy L.; Huber, Rebekah S.; McGlade, Erin C.; Jeong, Eun-Kee; Renshaw, Perry F.

2015-01-01

Background A high prevalence of tobacco smoking has been observed in methamphetamine users, but there have been no in vivo brain neurochemistry studies addressing gender effects of tobacco smoking in methamphetamine users. Methamphetamine addiction is associated with increased risk of depression and anxiety in females. There is increasing evidence that selective analogues of nicotine, a principal active component of tobacco smoking, may improve depression and cognitive performance in animals and humans. Objectives To investigate the effects of tobacco smoking and gender on brain phosphocreatine (PCr) levels, a marker of brain energy metabolism reported to be reduced in methamphetamine-dependent subjects. Methods Thirty female and twenty-seven male methamphetamine-dependent subjects were evaluated with phosphorus-31 magnetic resonance spectroscopy (31P-MRS) to measure PCr levels within the pregenual anterior cingulate, which has been implicated in methamphetamine neurotoxicity. Results Analysis of covariance revealed that there were statistically significant slope (PCr versus lifetime amount of tobacco smoking) differences between female and male methamphetamine-dependent subjects (p=0.03). In females, there was also a statistically significant interaction between lifetime amounts of tobacco smoking and methamphetamine in regard to PCr levels (p=0.01), which suggests that tobacco smoking may have a more significant positive impact on brain PCr levels in heavy, as opposed to light to moderate, methamphetamine-dependent females. Conclusion These results indicate that tobacco smoking has gender-specific effects in terms of increased anterior cingulate high energy PCr levels in methamphetamine-dependent subjects. Cigarette smoking in methamphetamine-dependent women, particularly those with heavy methamphetamine use, may have a potentially protective effect upon neuronal metabolism. PMID:25871447

Differential effects of ibogaine on local cerebral glucose utilization in drug-naive and morphine-dependent rats.

PubMed

Levant, Beth; Pazdernik, Thomas L

2004-04-02

Ibogaine, a hallucinogenic indole alkaloid, has been proposed as a treatment for addiction to opioids and other drugs of abuse. The mechanism for its putative anti-addictive effects is unknown. In this study, the effects of ibogaine on local cerebral glucose utilization (LCGU) were determined in freely moving, drug-naive, or morphine-dependent adult, male, Sprague-Dawley rats using the [(14)C]2-deoxyglucose (2-DG) method. Morphine-dependent rats were treated with increasing doses of morphine (5-25 mg/kg, s.c., b.i.d.) and then maintained at 25 mg/kg (b.i.d.) for 4-7 days. For the 2-DG procedure, rats were injected with saline or ibogaine (40 mg/kg, i.p.). 2-DG was administered 1 h after administration of ibogaine. The rate of LCGU was determined by quantitative autoradiography in 46 brain regions. In drug-naive animals, ibogaine produced significant increases in LCGU in the parietal, cingulate, and occipital cortices and cerebellum compared to controls consistent with its activity as a hallucinogen and a tremorogen. Morphine-dependent rats had only minor alterations in LCGU at the time assessed in this experiment. However, in morphine-dependent animals, ibogaine produced a global decrease in LCGU that was greatest in brain regions such as the lateral and medial preoptic areas, nucleus of the diagonal band, nucleus accumbens shell, inferior colliculus, locus coeruleus, and flocculus compared to morphine-dependent animals treated with saline. These findings indicate that ibogaine produces distinctly different effects on LCGU in drug-naive and morphine-dependent rats. This suggests that different mechanisms may underlie ibogaine's hallucinogenic and anti-addictive effects.

Who benefits from family support? Work schedule and family differences.

PubMed

Jennings, Kristen S; Sinclair, Robert R; Mohr, Cynthia D

2016-01-01

Prior research has demonstrated the benefits of family-supportive organization perceptions (FSOP) for reducing stress, increasing satisfaction, and increasing worker commitment; however, less research has studied health outcomes or possible differences in the effects of FSOP based on worker characteristics. The present study examined relationships between FSOP and health outcomes, as well as how those relationships may depend on work schedule and family differences. Using a sample of 330 acute care nurses, the findings indicated that FSOP predicted several health and well-being outcomes obtained 9 months later. Further, the relationships between FSOP and the outcome variables depended on some work schedule and family differences. In terms of family differences, FSOP was most strongly related to life satisfaction for those who cared for dependent adults. The relationship between FSOP and health outcomes of depression, musculoskeletal pain, and physical health symptoms were generally significant for workers with dependent children, but not significant for workers with no children. Regarding schedule differences, the relationship between FSOP and life satisfaction was significant for those on nonstandard (evening/night) shifts but not significant for standard day shift workers; however, there were no differences in FSOP relationships by number of hours worked per week. The findings demonstrate that FSOP may benefit some employees more than others. Such differences need to be incorporated into both future work-family theory development and into efforts to document the effectiveness of family-supportive policies, programs, and practices. (c) 2016 APA, all rights reserved).

Defensive effects of extrafloral nectaries in quaking aspen differ with scale

Treesearch

Brent Mortensen; Diane Wagner; Patricia Doak

2010-01-01

The effects of plant defenses on herbivory can differ among spatial scales. This may be particularly common with indirect defenses, such as extrafloral nectarines (EFNs), that attract predatory arthropods and are dependent on predator distribution, abundance, and behavior. We tested the defensive effects of EFNs in quaking aspen (Populus tremuloides...

[Spatial scale effect of land use landscape pattern in Yongdeng County, Gansu Province, China.

PubMed

Liu, Yuan Yuan; Liu, Xue Lu

2016-04-22

Based on "patch-corridor-matrix" pattern, spatial scale effect of landscape pattern was studied in Yongdeng County of Lanzhou City, Gansu Province, China. The results showed that the grassland was the matrix of landscape structure in the studied area, road and river played the corridor role, and the other landscape elements (cultivated land, forest land, garden land, residential land, industrial and mineral land, public management and service land, and the other land) acted as patches. The patch level index and the landscape level index all showed obvious dependence on spatial extent. The scale effect of patch index of different landscape elements existed differently in different extent intervals, so did the scale effect of the landscape level index. Within the extent of 1-20 km, the scale effect showed the most obvious difference between the element types and the index types, while it became smaller in 21-90 km, and disappeared beyond 90 km. 90 km×90 km might be the effective extent to study the dependence of spatial extent of landscape structure.

WITHDRAWN: Carbamazepine for cocaine dependence.

PubMed

Lima Reisser, Anelise A R L; Silva de Lima, Mauricio; Soares, Bernardo Garcia de Oliveira; Farrell, Michael

2009-01-21

Cocaine dependence has become a public health problem, developing a significant number of medical, psychological and social problems. Although there is no consensus regarding how to treat cocaine dependence, effective pharmacotherapy has a potentially major role to play as part of a broader treatment milieu. The anti-convulsant carbamazepine, a tricyclic medication that is widely used to treat a variety of neurological and psychiatric disorders, has been used for treatment of cocaine dependence, although its effectiveness has not been established. To determine whether carbamazepine is effective for the treatment of cocaine dependence. We searched: Cochrane Controlled Trials Register (Cochrane Library issue 1, 1999), MEDLINE (f1966 - October 1997), EMBASE (1980 - October 1997), PsycLIT (1974 - July 1997), Biological Abstracts and LILACS (1982 - 1997); scan of reference list of relevant articles; personal communication; conference abstracts; unpublished trials from pharmaceutical industry; book chapters on treatment of cocaine dependence. The specialised register of trials of Cochrane Group on Drugs and Alcohol until February 2003. All randomised controlled trials focused on the use of carbamazepine versus placebo on the treatment of cocaine dependence. Trials including patients with additional diagnosis such as opiate dependence were also eligible. The reviewers extracted the data independently, Odds Ratios, weighted mean difference and number needed to treat were estimated. Qualitative assessments of the methodology of eligible studies were carried out using validated checklists. The reviewers assumed that people who died or dropped out had no improvement and tested the sensitivity of the final results to this assumption. Where possible analysis was carried out according to the "intention to treat" principles. 5 studies were included (455 participants). No differences regarding positive urine sample for cocaine metabolites. Scores on Spielberg State Anxiety Inventory slightly favoured carbamazepine, but not statistical significance. Dropouts were high in both groups, less dropout occurred in the carbamazepine group (RR 0.87 95%CI 0.71-1.06). When no retention in treatment was due to side effects no differences were found. The number of participants presenting at least one side effect, was higher in the carbamazepine group (RR 4.33 95% CI 1.45-12.91). There is no current evidence supporting the clinical use of Carbamazepine in the treatment of cocaine dependence. Larger randomised investigation must be considered taking into account that these time-consuming efforts should be reserved for medications showing more relevant and promising evidence.

Apoptotic effects on cultured cells of atmospheric-pressure plasma produced using various gases

NASA Astrophysics Data System (ADS)

Tominami, Kanako; Kanetaka, Hiroyasu; Kudo, Tada-aki; Sasaki, Shota; Kaneko, Toshiro

2016-01-01

This study investigated the effects of low-temperature atmospheric-pressure plasma on various cells such as rat fibroblastic Rat-1 cell line, rat neuroblastoma-like PC12 cell line, and rat macrophage-like NR8383 cell line. The plasma was irradiated directly to a culture medium containing plated cells for 0-20 s. The applied voltage, excitation frequency, and argon or helium gas flow were, respectively, 3-6 kV, 10 kHz, and 3 L/min. Cell viability and apoptotic activity were evaluated using annexin-V/propidium iodide staining. Results showed that the low-temperature atmospheric-pressure plasma irradiation promoted cell death in a discharge-voltage-dependent and irradiation-time-dependent manner. Furthermore, different effects are produced depending on the cell type. Moreover, entirely different mechanisms might be responsible for the induction of apoptosis in cells by helium and argon plasma.

Organic Matter Composition, Recycling Susceptibility, and the Effectiveness of the Biological Pump – An Evaluation Using NMR Spectra of Marine Plankton

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paytan, Adina

Carbon (C) sequestration through fertilization of phytoplankton with micronutrients and enhancement of the absorption and retention of atmospheric C by ocean biota heavily depends on the efficiency of the “biological pump”. The long-term effectiveness of this strategy depends on a net transfer of C from the upper ocean-atmosphere system to the deep ocean where the C is removed from contact with the atmosphere for an extended period of time. This C removal can be equated to the amount of C fixation by phytoplankton minus the C cycling and regeneration in the euphotic zone. If the regeneration efficiency is increased, thenmore » despite increased C fixation, no net loss (sequestration) of C will result. A reduction in cycling efficiency in the euphotic zone, on the other hand, will increase the effectiveness of the “biological pump” and thus C sequestration. The degree of organic matter biodegradation and recycling depends on the “reactivity” of compounds synthesized by the biota, which in turn, is controlled by the structural characteristic of these compounds. There is considerable evidence that different phytoplankton taxa differ substantially in their biogeochemical characteristics and it is likely that the relative abundance of different compounds synthesized by these distinct taxa, and even within each group at different growth conditions, will differ too. This variability in biosynthesis and thus abundance of a wide range of organic compounds in the water column would lend itself to different susceptibility for biodegradation and regeneration. Knowledge of the distribution of various organic matter structural groups synthesized by distinct taxa, the dependence of the organic matter compound classes on different growth conditions (temperature, light, nutrients) and the selective susceptibility of these compound to regeneration is crucial for estimating the potential for rapid regeneration in the euphotic zone, and thus the effectiveness of the “biological pump”.« less

Neurocognitive performance in drug-dependent males and females with posttraumatic stress disorder symptoms.

PubMed

Paxton, Jessica L; Vassileva, Jasmin; Gonzalez, Raul; Maki, Pauline M; Martin, Eileen M

2012-01-01

Sex differences in neurobiological mechanisms of substance dependence are well documented but studies of sex differences in associated neurocognitive deficits have produced inconsistent results. Posttraumatic stress disorder (PTSD) is comorbid with substance dependence and frequently affects neurocognition. Thus, we investigated the effects of sex and PTSD symptoms on sustained attention and inhibition abilities among 126 female and 297 male substance-dependent individuals (SDIs) using the Immediate Memory Test (IMT). Females with significant PTSD (PTSD+) symptoms demonstrated significantly impaired IMT performance relative to other participants. These results represent progress in efforts to delineate sex-specific risk factors for neurocognitive deficits among SDIs.

Cost-effectiveness of adjuvant treatment with acamprosate in maintaining abstinence in alcohol dependent patients.

PubMed

Rychlik, R; Siedentop, H; Pfeil, T; Daniel, D

2003-04-01

An open prospective cohort study was performed in Germany in order to evaluate the costs of treating alcohol dependence under real-world conditions. Eight hundred and fourteen recently detoxified alcohol-dependent patients were provided with psychosocial rehabilitation support. In addition, 540 alcohol-dependent patients treated with adjuvant acamprosate therapy were compared with 274 patients without pharmacotherapy. Real costs were assessed over a period of one year. Of the patients who were treated with acamprosate, 33.6% remained abstinent compared to only 21.1% in the standard cohort. The mean total costs per patient treated with acamprosate were EUR 1,631.49 per year. In the standard cohort, total costs were EUR 2,068.83. This difference is highly significant (p = 0.012). Direct costs amounted to 76.9% of the total costs, with a 27% difference between the cohorts (p < 0.001). There was no difference in indirect costs between the two groups (p = 0.324). This real-cost study confirms the favourable cost-effectiveness of acamprosate previously suggested by pharmaco-economic modelling studies. Copyright 2003 S. Karger AG, Basel

Task-dependency and structure-dependency in number interference effects in sentence comprehension

PubMed Central

Franck, Julie; Colonna, Saveria; Rizzi, Luigi

2015-01-01

We report three experiments on French that explore number mismatch effects in intervention configurations in the comprehension of object A’-dependencies, relative clauses and questions. The study capitalizes on the finding of object attraction in sentence production, in which speakers sometimes erroneously produce a verb that agrees in number with a plural object in object relative clauses. Evidence points to the role of three critical constructs from formal syntax: intervention, intermediate traces and c-command (Franck et al., 2010). Experiment 1, using a self-paced reading procedure on these grammatical structures with an agreement error on the verb, shows an enhancing effect of number mismatch in intervention configurations, with faster reading times with plural (mismatching) objects. Experiment 2, using an on-line grammaticality judgment task on the ungrammatical versions of these structures, shows an interference effect in the form of attraction, with slower response times with plural objects. Experiment 3 with a similar grammaticality judgment task shows stronger attraction from c-commanding than from preceding interveners. Overall, the data suggest that syntactic computations in performance refer to the same syntactic representations in production and comprehension, but that different tasks tap into different processes involved in parsing: whereas performance in self-paced reading reflects the intervention of the subject in the process of building an object A’-dependency, performance in grammaticality judgment reflects intervention of the object on the computation of the subject-verb agreement dependency. The latter shows the hallmarks of structure-dependent attraction effects in sentence production, in particular, a sensitivity to specific characteristics of hierarchical representations. PMID:25914652

The Effects of Formalism on Teacher Trainees' Algebraic and Geometric Interpretation of the Notions of Linear Dependency/Independency

ERIC Educational Resources Information Center

Ertekin, E.; Solak, S.; Yazici, E.

2010-01-01

The aim of this study is to identify the effects of formalism in teaching on primary and secondary school mathematics teacher trainees' algebraic and geometric interpretations of the notions of linear dependency/independency. Quantitative research methods are drawn in order to determine differences in success levels between algebraic and geometric…

Electrophoretic mobilities of erythrocytes in various buffers

NASA Technical Reports Server (NTRS)

Plank, L. D.; Kunze, M. E.; Todd, P. W.

1985-01-01

The calibration of space flight equipment depends on a source of standard test particles, this test particle of choice is the fixed erythrocyte. Erythrocytes from different species have different electrophoretic mobilities. Electrophoretic mobility depends upon zeta potential, which, in turn depends upon ionic strength. Zeta potential decreases with increasing ionic strength, so cells have high electrophoretic mobility in space electrophoresis buffers than in typical physiological buffers. The electrophoretic mobilities of fixed human, rat, and rabbit erythrocytes in 0.145 M salt and buffers of varying ionic strength, temperature, and composition, to assess the effects of some of the unique combinations used in space buffers were characterized. Several effects were assessed: glycerol or DMSO (dimethylsulfoxide) were considered for use as cryoprotectants. The effect of these substances on erythrocyte electrophoretic mobility was examined. The choice of buffer depended upon cell mobility. Primary experiments with kidney cells established the choice of buffer and cryoprotectant. A nonstandard temperature of EPM in the suitable buffer was determined. A loss of ionic strength control occurs in the course of preparing columns for flight, the effects of small increases in ionic strength over the expected low values need to be evaluated.

Quasi-stationary states of an electron with linearly dependent effective mass in an open nanostructure within transmission coefficient and S-matrix methods

NASA Astrophysics Data System (ADS)

Seti, Julia; Tkach, Mykola; Voitsekhivska, Oxana

2018-03-01

The exact solutions of the Schrödinger equation for a double-barrier open semiconductor plane nanostructure are obtained by using two different approaches, within the model of the rectangular potential profile and the continuous position-dependent effective mass of the electron. The transmission coefficient and scattering matrix are calculated for the double-barrier nanostructure. The resonance energies and resonance widths of the electron quasi-stationary states are analyzed as a function of the size of the near-interface region between wells and barriers, where the effective mass linearly depends on the coordinate. It is established that, in both methods, the increasing size affects in a qualitatively similar way the spectral characteristics of the states, shifting the resonance energies into the low- or high-energy region and increasing the resonance widths. It is shown that the relative difference of resonance energies and widths of a certain state, obtained in the model of position-dependent effective mass and in the widespread abrupt model in physically correct range of near-interface sizes, does not exceed 0.5% and 5%, respectively, independently of the other geometrical characteristics of the structure.

Implications in studies of environmental risk assessments: Does culture medium influence the results of toxicity tests of marine bacteria?

PubMed

Díaz-García, Alejandra; Borrero-Santiago, Ana R; Riba, Inmaculada

2018-04-14

Two marine bacterial populations (Roseobacter sp. and Pseudomonas litoralis) were exposed to different concentrations of zinc (300, 625, 1250, 2000, 2500 and 5000 mg L -1 ) and cadmium (75, 250, 340, 500 and 1000 mg L -1 ) using two culture media (full nutrient Marine Broth 2216 "MB" and 1:10 (vol/vol) dilution with seawater of Marine Broth 2216 "MB SW "), in order to assess population responses depending on the culture medium and also potential adverse effects associated with these two metals. Different responses were found depending on the culture medium (Bacterial abundance (cells·mL -1 ), growth rates (μ, hours -1 ), and production of Extracellular Polysaccharides Substances (EPS) (μg glucose·cells -1 ). Results showed negative effects in both strains after the exposure to Zn treatments. Both strains showed highest metal sensitivity at low concentrations using both culture media. However, different results were found when exposing the bacterial populations to Cd treatments depending on the culture medium. Highest toxicity was observed using MB at low levels of Cd concentrations, whereas MB SW showed toxicity to bacteria at higher concentrations of Cd. Results not only showed adverse effects on Roseobacter sp. and Pseudomonas litoralis associated with the concentration of Zn and Cd, but also confirm that depending on the culture medium results can differ. This work suggests MB SW as an adequate culture medium to study metal toxicity bioassays in order to predict realistic effects on marine bacterial populations. Copyright © 2018 Elsevier Ltd. All rights reserved.

The Effects of Literacy and Education on the Income of America's Young Adults.

ERIC Educational Resources Information Center

Mok, Yan Fung

1996-01-01

Effects of prose, document, and quantitative literacy and education on the wages of 1,456 young adults who worked full time were analyzed. Literacy and education did not have the same effects on income for all groups; not all groups depended on literacy and education to increase income. Different types of literacy had different effects on gender…

Corrugated grating on organic multilayer Bragg reflector

NASA Astrophysics Data System (ADS)

Jaquet, Sylvain; Scharf, Toralf; Herzig, Hans Peter

2007-08-01

Polymeric multilayer Bragg structures are combined with diffractive gratings to produce artificial visual color effects. A particular effect is expected due to the angular reflection dependence of the multilayer Bragg structure and the dispersion caused by the grating. The combined effects can also be used to design particular filter functions and various resonant structures. The multilayer Bragg structure is fabricated by spin-coating of two different low-cost polymer materials in solution on a cleaned glass substrate. These polymers have a refractive index difference of about 0.15 and permit multilayer coatings without interlayer problems. Master gratings of different periods are realized by laser beam interference and replicated gratings are superimposed on the multilayer structure by soft embossing in a UV curing glue. The fabrication process requires only polymer materials. The obtained devices are stable and robust. Angular dependent reflection spectrums for the visible are measured. These results show that it is possible to obtain unexpected reflection effects. A rich variety of color spectra can be generated, which is not possible with a single grating. This can be explained by the coupling of transmission of grating orders and the Bragg reflection band. A simple model permits to explain some of the spectral vs angular dependence of reflected light.

Investigating the Impact of Internet Dependency on Student-Teachers' Loneliness of Adiyaman University

ERIC Educational Resources Information Center

Aytaç, Kürsat Yusuf

2018-01-01

This research was conducted to investigate the effect of internet dependency on student- teachers' loneliness of Admiyaman University. The study also examined the differences in internet dependency and loneliness among students and teachers of Adiyaman University of Turkey. The standard questionnaire of Jung (1996) was used to measure the internet…

Polygenic variation maintained by balancing selection: pleiotropy, sex-dependent allelic effects and G x E interactions.

PubMed Central

Turelli, Michael; Barton, N H

2004-01-01

We investigate three alternative selection-based scenarios proposed to maintain polygenic variation: pleiotropic balancing selection, G x E interactions (with spatial or temporal variation in allelic effects), and sex-dependent allelic effects. Each analysis assumes an additive polygenic trait with n diallelic loci under stabilizing selection. We allow loci to have different effects and consider equilibria at which the population mean departs from the stabilizing-selection optimum. Under weak selection, each model produces essentially identical, approximate allele-frequency dynamics. Variation is maintained under pleiotropic balancing selection only at loci for which the strength of balancing selection exceeds the effective strength of stabilizing selection. In addition, for all models, polymorphism requires that the population mean be close enough to the optimum that directional selection does not overwhelm balancing selection. This balance allows many simultaneously stable equilibria, and we explore their properties numerically. Both spatial and temporal G x E can maintain variation at loci for which the coefficient of variation (across environments) of the effect of a substitution exceeds a critical value greater than one. The critical value depends on the correlation between substitution effects at different loci. For large positive correlations (e.g., rho(ij)2>3/4), even extreme fluctuations in allelic effects cannot maintain variation. Surprisingly, this constraint on correlations implies that sex-dependent allelic effects cannot maintain polygenic variation. We present numerical results that support our analytical approximations and discuss our results in connection to relevant data and alternative variance-maintaining mechanisms. PMID:15020487

Effect of soil texture on the microwave emission from soils

NASA Technical Reports Server (NTRS)

Schmugge, T. J.

1980-01-01

The intensity brightness temperature of the microwave emission from the soil is determined primarily by its dielectric properties. The large difference between the dielectric constant of water and that of dry soil produces a strong dependence of the soil's dielectric constant on its moisture content. This dependence is effected by the texture of the soil because the water molecules close to the particle surface are tightly bound and do not contribute significantly to the dielectric properties. Since this surface area is a function of the particle size distribution (soil texture), being larger for clay soils with small particles, and smaller for sandy soils with larger particles; the dielectric properties will depend on soil texture. Laboratory measurements of the dielectric constant for soils are summarized. The dependence of the microwave emission on texture is demonstrated by measurements of brightness temperature from an aircraft platform for a wide range of soil textures. It is concluded that the effect of soil texture differences on the observed values can be normalized by expressing the soil moisture values as a percent field capacity for the soil.

Response to varying the nicotine content of cigarettes in vulnerable populations: an initial experimental examination of acute effects.

PubMed

Higgins, Stephen T; Heil, Sarah H; Sigmon, Stacey C; Tidey, Jennifer W; Gaalema, Diann E; Stitzer, Maxine L; Durand, Hanna; Bunn, Janice Y; Priest, Jeff S; Arger, Christopher A; Miller, Mollie E; Bergeria, Cecilia L; Davis, Danielle R; Streck, Joanna M; Zvorsky, Ivori; Redner, Ryan; Vandrey, Ryan; Pacek, Lauren R

2017-01-01

The purpose of this study was to begin researching the effects of very low nicotine content cigarettes in smokers especially vulnerable to dependence to assess their potential as a less dependence-producing alternative to current commercial cigarettes. Participants were 26 adult, daily cigarette smokers from one of three populations: economically disadvantaged women of reproductive age (n = 9), opioid-dependent individuals (n = 11), and individuals with affective disorders (n = 6). Participants completed fourteen 2-4-h experimental sessions in a within-subjects research design. Sessions were conducted following brief smoking abstinence. Four research cigarettes varying in nicotine content (0.4, 2.4, 5.2, and 15.8 mg/g) were studied under double-blind conditions, assessing smoking topography, subjective effects, and relative reinforcing effects of varying doses in concurrent choice tests. Results were collapsed across vulnerable populations and analyzed using repeated measures ANOVA. No significant differences between doses were discernible in smoking topography. All doses were equi-effective at reducing nicotine withdrawal. Ratings of satisfaction from smoking were lower at the 0.4 compared to 15.8 mg/g dose. Participants preferred the 15.8 mg/g dose over the 0.4 and 2.4 but not the 5.2 mg/g doses in concurrent choice testing; no differences between the two lowest doses were noted. All cigarettes effectively reduced nicotine withdrawal with no differences in smoking topography, suggesting minimal compensatory smoking. Dependence potential was lowest at the 0.4 mg/g dose. These initial results are promising regarding the feasibility of lowering nicotine content in cigarettes to very low levels in vulnerable populations without untoward effects.

Apolipoprotein E4 Causes Age- and Sex-Dependent Impairments of Hilar GABAergic Interneurons and Learning and Memory Deficits in Mice

PubMed Central

Leung, Laura; Andrews-Zwilling, Yaisa; Yoon, Seo Yeon; Jain, Sachi; Ring, Karen; Dai, Jessica; Wang, Max Mu; Tong, Leslie; Walker, David; Huang, Yadong

2012-01-01

Apolipoprotein (apo) E4 is the major genetic risk factor for Alzheimer's disease (AD). ApoE4 has sex-dependent effects, whereby the risk of developing AD is higher in apoE4-expressing females than males. However, the mechanism underlying the sex difference, in relation to apoE4, is unknown. Previous findings indicate that apoE4 causes age-dependent impairments of hilar GABAergic interneurons in female mice, leading to learning and memory deficits. Here, we investigate whether the detrimental effects of apoE4 on hilar GABAergic interneurons are sex-dependent using apoE knock-in (KI) mice across different ages. We found that in female apoE-KI mice, there was an age-dependent depletion of hilar GABAergic interneurons, whereby GAD67- or somatostatin-positive–but not NPY- or parvalbumin-positive–interneuron loss was exacerbated by apoE4. Loss of these neuronal populations was correlated with the severity of spatial learning deficits at 16 months of age in female apoE4-KI mice; however, this effect was not observed in female apoE3-KI mice. In contrast, we found an increase in the numbers of hilar GABAergic interneurons with advancing age in male apoE-KI mice, regardless of apoE genotype. Moreover, male apoE-KI mice showed a consistent ratio of hilar inhibitory GABAergic interneurons to excitatory mossy cells approximating 1.5 that is independent of apoE genotype and age, whereas female apoE-KI mice exhibited an age-dependent decrease in this ratio, which was exacerbated by apoE4. Interestingly, there are no apoE genotype effects on GABAergic interneurons in the CA1 and CA3 subregions of the hippocampus as well as the entorhinal and auditory cortexes. These findings suggest that the sex-dependent effects of apoE4 on developing AD is in part attributable to inherent sex-based differences in the numbers of hilar GABAergic interneurons, which is further modulated by apoE genotype. PMID:23300939

Analysis of opioid efficacy, tolerance, addiction and dependence from cell culture to human.

PubMed

Morgan, Michael M; Christie, MacDonald J

2011-10-01

Opioid agonists are the most effective treatment for pain, but their use is limited by side effects, tolerance and fears of addiction and dependence. A major goal of opioid research is to develop agonists that have high analgesic efficacy and a low profile for side effects, tolerance, addiction and dependence. Unfortunately, there is a serious lack of experimental data comparing the degree to which different opioids produce these effects in humans. In contrast, a wide range of experimental techniques from heterologous expression systems to behaviour assessment in whole animals have been developed to study these problems. The objective of this review is to describe and evaluate these techniques as they are used to study opioid efficacy, tolerance, addiction and dependence. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society.

Quantum interference effects on the intensity of the G modes in double-walled carbon nanotubes

DOE PAGES

Tran, Huy Nam; Blancon, Jean-Christophe Robert; Arenal, Raul; ...

2017-05-08

The effects of quantum interferences on the excitation dependence of the intensity of G modes have been investigated on single-walled carbon nanotubes [Duque et al., Phys. Rev. Lett.108, 117404 (2012)]. In this work, by combining optical absorption spectroscopy and Raman scattering on individual index identified double-walled carbon nanotubes, we examine the experimental excitation dependence of the intensity of longitudinal optical and transverse optical G modes of the constituent inner and outer single-walled carbon nanotubes. The observed striking dependencies are understood in terms of quantum interference effects. Considering such effects, the excitation dependence of the different components of the G modesmore » permit to unambiguously assign each of them as originating from the longitudinal or transverse G modes of inner and outer tubes.« less

Quantum interference effects on the intensity of the G modes in double-walled carbon nanotubes

NASA Astrophysics Data System (ADS)

Tran, H. N.; Blancon, J.-C.; Arenal, R.; Parret, R.; Zahab, A. A.; Ayari, A.; Vallée, F.; Del Fatti, N.; Sauvajol, J.-L.; Paillet, M.

2017-05-01

The effects of quantum interferences on the excitation dependence of the intensity of G modes have been investigated on single-walled carbon nanotubes [Duque et al., Phys. Rev. Lett. 108, 117404 (2012), 10.1103/PhysRevLett.108.117404]. In this work, by combining optical absorption spectroscopy and Raman scattering on individual index identified double-walled carbon nanotubes, we examine the experimental excitation dependence of the intensity of longitudinal optical and transverse optical G modes of the constituent inner and outer single-walled carbon nanotubes. The observed striking dependencies are understood in terms of quantum interference effects. Considering such effects, the excitation dependence of the different components of the G modes permits us to unambiguously assign each of them as originating from the longitudinal or transverse G modes of inner and outer tubes.

Quantum interference effects on the intensity of the G modes in double-walled carbon nanotubes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tran, Huy Nam; Blancon, Jean-Christophe Robert; Arenal, Raul

The effects of quantum interferences on the excitation dependence of the intensity of G modes have been investigated on single-walled carbon nanotubes [Duque et al., Phys. Rev. Lett.108, 117404 (2012)]. In this work, by combining optical absorption spectroscopy and Raman scattering on individual index identified double-walled carbon nanotubes, we examine the experimental excitation dependence of the intensity of longitudinal optical and transverse optical G modes of the constituent inner and outer single-walled carbon nanotubes. The observed striking dependencies are understood in terms of quantum interference effects. Considering such effects, the excitation dependence of the different components of the G modesmore » permit to unambiguously assign each of them as originating from the longitudinal or transverse G modes of inner and outer tubes.« less

Effects of different dosages of propylene glycol in dry cows and cows in early lactation.

PubMed

Maurer, Michaela; Peinhopf, Walter; Gottschalk, Jutta; Einspanier, Almut; Koeller, Gabor; Wittek, Thomas

2017-11-01

In this Research Paper we hypothesised that the temporary insulin resistance seen during the transition period in dairy cows may cause significant differences in the efficacy of PG at different sampling periods and that in some cases this effect will be dose dependent. Eighty four sampling sets were generated by studying 7 multiparous Holstein cows repeatedly at 4 sampling periods of 3 d length (dry cows: days 40, 39 and 38 antepartum; close up cows: days 10, 9 and 8 antepartum; fresh cows: days 3, 4 and 5 post-partum; lactating cows: days 38, 39 and 40 post-partum). On each of these days 3 h after morning feeding propylene glycol was drenched in different dosages of 100, 300 or 500 ml once per day (cross over study). The different doses were applied in an alternating order (Latin square). Blood samples were taken before, every 30 min up to 4 h, after 6 and 12 h after PG application. Following parameters have been measured: insulin, non-esterified fatty acids (NEFA), betahydroxybutyrate (BHB), bilirubin, cholesterol, potassium, aspartate aminotransferase (AST) and glutamate dehydrogenase (GLDH). Revised Quantitative Insulin Sensitivity Check Index (RQUICKI) was calculated. It was found that glucose, insulin, NEFA, BHB, bilirubin and potassium concentrations were influenced differently by the three defined dosages of propylene glycol at four different sampling periods. Whereas RQUICKI, cholesterol, AST and GLDH did not differ between the sampling periods and treatments. The major results of the study are that the effect of PG is dose-dependent and that the effect of PG is depending on the time of application according to calving. It can be concluded that in fresh cows higher dosages are necessary to provoke similar effects in comparison to dry, close up and lactating cows. Although the study did not compare to topdressing of PG from the results it is reasonable to believe that bolus application of a specific PG volume is necessary to provoke the effect.

My starting point: the discovery of an NMR method for measuring blood oxygenation using the transverse relaxation time of blood water.

PubMed

Thulborn, Keith R

2012-08-15

This invited personal story, covering the period from 1979 to 2010, describes the discovery of the dependence of the transverse relaxation time of water in blood on the oxygenation state of hemoglobin in the erythrocytes. The underlying mechanism of the compartmentation of the different magnetic susceptibilities of hemoglobin in its different oxygenation states also explains the mechanism that underlies blood oxygenation level dependent contrast used in fMRI. The story begins with the initial observation of line broadening during ischemia in small rodents detected by in vivo 31P NMR spectroscopy at high field. This spectroscopic line broadening or T2* relaxation effect was demonstrated to be related to the oxygenation state of blood. The effect was quantified more accurately using T2 values measured by the Carr-Purcell-Meiboom-Gill method. The effect was dependent on the integrity of the erythrocytes to compartmentalize the different magnetic susceptibilities produced by the changing spin state of the ferrous iron of hemoglobin in its different oxygenation states between the erythrocytes and the suspending solution. The hematocrit and magnetic field dependence, the requirement for erythrocyte integrity and lack of T1 dependence confirmed that the magnetic susceptibility effect explained the oxygenation state dependence of T2* and T2. This T2/T2* effect was combined with T1 based measurements of blood flow to measure oxygen consumption in animals. This blood oxygenation assay and its underlying magnetic susceptibility gradient mechanism was published in the biochemistry literature in 1982 and largely forgotten. The observation was revived to explain evolving imaging features of cerebral hematoma as MR imaging of humans increased in field strength to 1.5 T by the mid 1980s. Although the imaging version of this assay was used to measure a global metabolic rate of cerebral oxygen consumption in humans at 1.5-T by 1991, the global measurement had little clinical value. By contrast, a decade after the spectroscopic observation, imaging experiments performed on rodents at 7 T by Ogawa and colleagues identified the extravascular T2* imaging characteristics of the blood oxygenation effect and, most importantly, associated that change with brain functional states. Ogawa appropriately branded this blood oxygenation level dependent mechanism as BOLD contrast. This mechanism was subsequently shown to be the basis of localized MR signal changes associated with local brain function. This connection led to the fMRI revolution in human brain mapping. Copyright © 2012. Published by Elsevier Inc.

On the Nature of Clitics and Their Sensitivity to Number Attraction Effects

PubMed Central

Santesteban, Mikel; Zawiszewski, Adam; Erdocia, Kepa; Laka, Itziar

2017-01-01

Pronominal dependencies have been shown to be more resilient to attraction effects than subject-verb agreement. We use this phenomenon to investigate whether antecedent-clitic dependencies in Spanish are computed like agreement or like pronominal dependencies. In Experiment 1, an acceptability judgment self-paced reading task was used. Accuracy data yielded reliable attraction effects in both grammatical and ungrammatical sentences, only in singular (but not plural) clitics. Reading times did not show reliable attraction effects. In Experiment 2, we measured electrophysiological responses to violations, which elicited a biphasic frontal negativity-P600 pattern. Number attraction modulated the frontal negativity but not the amplitude of the P600 component. This differs from ERP findings on subject-verb agreement, since when the baseline matching condition obtained a biphasic pattern, attraction effects only modulated the P600, not the preceding negativity. We argue that these findings support cue-retrieval accounts of dependency resolution and further suggest that the sensitivity to attraction effects shown by clitics resembles more the computation of pronominal dependencies than that of agreement. PMID:28928686

On the Nature of Clitics and Their Sensitivity to Number Attraction Effects.

PubMed

Santesteban, Mikel; Zawiszewski, Adam; Erdocia, Kepa; Laka, Itziar

2017-01-01

Pronominal dependencies have been shown to be more resilient to attraction effects than subject-verb agreement. We use this phenomenon to investigate whether antecedent-clitic dependencies in Spanish are computed like agreement or like pronominal dependencies. In Experiment 1, an acceptability judgment self-paced reading task was used. Accuracy data yielded reliable attraction effects in both grammatical and ungrammatical sentences, only in singular (but not plural) clitics. Reading times did not show reliable attraction effects. In Experiment 2, we measured electrophysiological responses to violations, which elicited a biphasic frontal negativity-P600 pattern. Number attraction modulated the frontal negativity but not the amplitude of the P600 component. This differs from ERP findings on subject-verb agreement, since when the baseline matching condition obtained a biphasic pattern, attraction effects only modulated the P600, not the preceding negativity. We argue that these findings support cue-retrieval accounts of dependency resolution and further suggest that the sensitivity to attraction effects shown by clitics resembles more the computation of pronominal dependencies than that of agreement.

Soil-borne pathogens restrict the recruitment of a subtropical tree: a distance-dependent effect.

PubMed

Xu, Meng; Wang, Yongfan; Liu, Yu; Zhang, Zhiming; Yu, Shixiao

2015-03-01

The Janzen-Connell hypothesis suggests that density- and/or distance-dependent juvenile mortality driven by host-specific natural enemies can explain high species diversity in tropical forests. However, such density and distance effects may not occur simultaneously and may not be driven by the same mechanism. Also, reports of attempts to identify and quantify the differences between these processes in tropical forests are scarce. In a primary subtropical forest in China, we (1) experimentally examined the relative influence of the distance to parent trees vs. conspecific seedling density on mortality patterns in Engelhardia fenzelii, (2) tested the role of soil-borne pathogens in driving density- or distance-dependent processes that cause seedling mortality, and (3) inspected the susceptibilities of different tree species to soil biota of E. fenzelii and the effects of soil biota from different tree species on E. fenzelii. The results from these field experiments showed that distance- rather than density-dependent processes driven by soil pathogens strongly affect the seedling survival of this species in its first year. We also observed increased survival of a fungicide treatment for E. fenzelii seedlings in the parent soil but not for the seedlings of the other three species in the E. fenzelii parent soil, or for E. fenzelii seedlings in the parent soil of three other species. This study illustrates how the distance-dependent pattern of seedling recruitment for this species is driven by soil pathogens, a mechanism that likely restricts the dominance of this abundant species.

Treatment of opioid dependence with buprenorphine: current update

PubMed Central

Soyka, Michael

2017-01-01

Opioid maintenance treatment is the first-line approach in opioid dependence. Both the full opioid agonist methadone (MET) and the partial agonist buprenorphine (BUP) are licensed for the treatment of opioid dependence. BUP differs significantly from MET in its pharmacology, side effects, and safety issues. For example, the risk of respiratory depression is lower than with MET. The risk of diversion and injection of BUP have been reduced by also making it available as a tablet containing the opioid antagonist naloxone. This review summarizes the clinical effects of BUP and examines possible factors that can support decisions regarding the use of BUP or MET in opioid-dependent people. PMID:29302227

The effects of nicotine dependence and acute abstinence on the processing of drug and non-drug rewards.

PubMed

Lawn, W; Freeman, T P; Hindocha, C; Mokrysz, C; Das, R K; Morgan, C J A; Curran, H V

2015-07-01

Drug addiction may be characterised by a hypersensitivity to drug rewards and a hyposensitivity to non-drug rewards. This imbalance may become further polarised during acute abstinence. (i) Examine the differences between dependent and occasional smokers in choices for, motivation for and self-reported wanting and liking of cigarette and non-drug rewards. (ii) Examine the effects of 12-h nicotine abstinence on these metrics. Dependent (n = 20) and occasional, non-dependent smokers (n = 20) were tested after ad libitum smoking and ≥12-h of nicotine abstinence. A novel task was developed (Drug, Reward and Motivation-Choice (DReaM-Choice)) in which different rewards (cigarettes, music and chocolate) could be won. In each trial, participants chose between two rewards and then could earn the chosen reward via repeated button-pressing. Participants subsequently 'consumed' and rated subjective liking of the rewards they had won. Compared with occasional smokers, dependent smokers made more choices for (p < 0.001), pressed more for (p = 0.046) and reported more wanting (p = 0.007) and liking (p < 0.001) of cigarettes, and also made fewer choices for chocolate (p = 0.005). There were no differences between the groups on button-pressing for chocolate or music. However, the balance between drug and non-drug reward processing was different between the groups across all metrics. Twelve-hour nicotine abstinence led to more cigarette choices (p < 0.001) and fewer music choices (p = 0.042) in both groups. Nicotine dependence was associated with a hypersensitivity to cigarette rewards, but we found little evidence indicating a hyposensitivity to non-drug rewards. Our findings question the moderating influence of dependence on how acute nicotine abstinence affects reward processing.

Effects of carotenoids on lipid bilayers.

PubMed

Johnson, Quentin R; Mostofian, Barmak; Fuente Gomez, Gabriel; Smith, Jeremy C; Cheng, Xiaolin

2018-01-31

Carotenoids have been found to be important in improving the integrity of biomembranes in eukaryotes. However, the molecular details of how carotenoids modulate the physical properties of biomembranes are unknown. To this end, we have conducted a series of molecular dynamics simulations of different biologically-relevant membranes in the presence of carotenoids. The carotenoid effect on the membrane was found to be specific to the identity of the carotenoid and the composition of the membrane itself. Therefore, different classes of carotenoids produce a different effect on the membrane, and different membrane phases are affected differently by carotenoids. It is apparent from our data that carotenoids do trigger the bilayer to become thinner. The mechanism by which this occurs depends on two competing factors, the ability of the lipid tails of opposing monolayers to either (1) compress or (2) interdigitate as the bilayer condenses. Indeed, carotenoids directly influence the physical properties via these two mechanisms, thus compacting the bilayer. However, the degree to which these competing mechanisms are utilized depends on the bilayer phase and the carotenoid identity.

[Pharmacokinetics and the clinical effect of bemitil after a single administration].

PubMed

Boĭko, S S; Bobkov, Iu G; Neznamov, G G; Serebriakova, T V

1986-01-01

It was found on studying a novel psychotropic drug bemitil that after its single administration kinetic curves significantly differed depending on a clinical effect of the test dose in patients with asthenic states. At predomination of the psychoactivating component of action one could note a larger area under the concentration-time relationship curve and a shorter period of half-excretion than in patients with the tranquilizing action. The obtained data on the difference in the drug test dose effect depending on the drug pharmacokinetics should be taken into consideration at determination of bemitil course therapy duration in patients with neuroses and neurosis-like states with predominance of asthenic disturbances in the clinical picture.

Decision-Making Under Risk, but Not Under Ambiguity, Predicts Pathological Gambling in Discrete Types of Abstinent Substance Users.

PubMed

Wilson, Michael J; Vassileva, Jasmin

2018-01-01

This study explored how different forms of reward-based decision-making are associated with pathological gambling (PG) among abstinent individuals with prior dependence on different classes of drugs. Participants had lifetime histories of either "pure" heroin dependence ( n = 64), "pure" amphetamine dependence ( n = 51), or polysubstance dependence ( n = 89), or had no history of substance dependence ( n = 133). Decision-making was assessed via two neurocognitive tasks: (1) the Iowa Gambling Task (IGT), a measure of decision-making under ambiguity (i.e., uncertain risk contingencies); and (2) the Cambridge Gambling task (CGT), a measure of decision-making under risk (i.e., explicit risk contingencies). The main effects of neurocognitive performance and drug class on PG (defined as ≥3 DSM-IV PG symptoms) as well as their interactional effects were assessed via multiple linear regression. Two CGT indices of decision-making under risk demonstrated positive main effects on PG. Interaction effects indicated that the effects of decision-making under risk on PG were largely consistent across participant groups. Notably, a linear relationship between greater CGT Risk-Taking and PG symptoms was not observed among amphetamine users, whereas IGT performance was selectively and positively associated with PG in polysubstance users. Overall, results indicate that reward-based decision-making under risk may represent a risk factor for PG across substance users, with some variations in these relationships influenced by specific class of substance of abuse.

The dependence of the sporicidal effects on the power and pressure of RF-generated plasma processes.

PubMed

Lassen, Klaus S; Nordby, Bolette; Grün, Reinar

2005-07-01

The sporicidal effect of 20 different radio-frequency plasma processes produced by combining five different gas mixtures [O(2), Ar/H(2) (50/50%), Ar/H(2) (5/95%), O(2)/H(2) (50/50%), O(2)/H(2) (95/5%)] with four power/pressure settings were tested. Sporicidal effects of oxygen-containing plasmas were dependent on power at low pressure settings but not at high pressure settings. In the absence of oxygen no power dependency was observed at either high or low pressure settings. Survivor curves obtained with the use of nonoxygen plasmas typically had a tailing tendency. Only a mixture-optimized Ar/H(2) (15/85%) plasma process was not encumbered by tailing, and produced a decimal reduction time (D value) below 2 min for Bacillus stearothermophilus spores. Scanning electron microscopy showed that a CF(4)/O(2) plasma did more damage to the substrate than the 15/85% Ar/H(2) plasma. The present results indicate that UV irradiation inactivation is swift and power and pressure independent. Additionally, it is produced at low energy. However, it is not complete. Inactivation through etching is highly power and pressure dependent; finally, inactivation by photodesorption is moderately power and pressure dependent. A sterilization process relying on this mechanism is very advantageous because it combines a highly sporicidal effect with low substrate damage. Copyright 2005 Wiley Periodicals, Inc.

Economic evaluation of interventions for problem drinking and alcohol dependence: do within-family external effects make a difference?

PubMed

Mortimer, Duncan; Segal, Leonie

2006-01-01

To propose methods for the inclusion of within-family external effects in clinical and economic evaluations. To demonstrate the extent of bias due to the exclusion of within-family external effects when measuring the relative performance of interventions for problem drinking and alcohol dependence. The timing and magnitude of treatment effects are modified to accommodate the external health-related quality of life impact of having a problem or dependent drinker in the family home. The inclusion of within-family external effects reduces cost per QALY estimates of interventions for problem drinking and alcohol dependence thereby improving the performance of all evaluated interventions. In addition, the inclusion of within-family external effects improves the relative performance of interventions targeted at those with moderate-to-severe alcohol dependence as compared to interventions targeted at less severe alcohol problems. Failure to take account of external effects in clinical and economic evaluations results in an uneven playing field. Interventions with readily quantifiable health benefits (where social costs and benefits are predominantly comprised of private costs and benefits) are at a distinct advantage when competing for public funding against interventions with quantitatively important external effects.

Predation and fragmentation portrayed in the statistical structure of prey time series

PubMed Central

Hendrichsen, Ditte K; Topping, Chris J; Forchhammer, Mads C

2009-01-01

Background Statistical autoregressive analyses of direct and delayed density dependence are widespread in ecological research. The models suggest that changes in ecological factors affecting density dependence, like predation and landscape heterogeneity are directly portrayed in the first and second order autoregressive parameters, and the models are therefore used to decipher complex biological patterns. However, independent tests of model predictions are complicated by the inherent variability of natural populations, where differences in landscape structure, climate or species composition prevent controlled repeated analyses. To circumvent this problem, we applied second-order autoregressive time series analyses to data generated by a realistic agent-based computer model. The model simulated life history decisions of individual field voles under controlled variations in predator pressure and landscape fragmentation. Analyses were made on three levels: comparisons between predated and non-predated populations, between populations exposed to different types of predators and between populations experiencing different degrees of habitat fragmentation. Results The results are unambiguous: Changes in landscape fragmentation and the numerical response of predators are clearly portrayed in the statistical time series structure as predicted by the autoregressive model. Populations without predators displayed significantly stronger negative direct density dependence than did those exposed to predators, where direct density dependence was only moderately negative. The effects of predation versus no predation had an even stronger effect on the delayed density dependence of the simulated prey populations. In non-predated prey populations, the coefficients of delayed density dependence were distinctly positive, whereas they were negative in predated populations. Similarly, increasing the degree of fragmentation of optimal habitat available to the prey was accompanied with a shift in the delayed density dependence, from strongly negative to gradually becoming less negative. Conclusion We conclude that statistical second-order autoregressive time series analyses are capable of deciphering interactions within and across trophic levels and their effect on direct and delayed density dependence. PMID:19419539

The wavelength dependent model of extinction in fog and haze for free space optical communication.

PubMed

Grabner, Martin; Kvicera, Vaclav

2011-02-14

The wavelength dependence of the extinction coefficient in fog and haze is investigated using Mie single scattering theory. It is shown that the effective radius of drop size distribution determines the slope of the log-log dependence of the extinction on wavelengths in the interval between 0.2 and 2 microns. The relation between the atmospheric visibility and the effective radius is derived from the empirical relationship of liquid water content and extinction. Based on these results, the model of the relationship between visibility and the extinction coefficient with different effective radii for fog and for haze conditions is proposed.

Temperature dependence of frequency response characteristics in organic field-effect transistors

NASA Astrophysics Data System (ADS)

Lu, Xubing; Minari, Takeo; Liu, Chuan; Kumatani, Akichika; Liu, J.-M.; Tsukagoshi, Kazuhito

2012-04-01

The frequency response characteristics of semiconductor devices play an essential role in the high-speed operation of electronic devices. We investigated the temperature dependence of dynamic characteristics in pentacene-based organic field-effect transistors and metal-insulator-semiconductor capacitors. As the temperature decreased, the capacitance-voltage characteristics showed large frequency dispersion and a negative shift in the flat-band voltage at high frequencies. The cutoff frequency shows Arrhenius-type temperature dependence with different activation energy values for various gate voltages. These phenomena demonstrate the effects of charge trapping on the frequency response characteristics, since decreased mobility prevents a fast charge response for alternating current signals at low temperatures.

The effect of zero-point energy differences on the isotope dependence of the formation of ozone: a classical trajectory study.

PubMed

Schinke, Reinhard; Fleurat-Lessard, Paul

2005-03-01

The effect of zero-point energy differences (DeltaZPE) between the possible fragmentation channels of highly excited O(3) complexes on the isotope dependence of the formation of ozone is investigated by means of classical trajectory calculations and a strong-collision model. DeltaZPE is incorporated in the calculations in a phenomenological way by adjusting the potential energy surface in the product channels so that the correct exothermicities and endothermicities are matched. The model contains two parameters, the frequency of stabilizing collisions omega and an energy dependent parameter Delta(damp), which favors the lower energies in the Maxwell-Boltzmann distribution. The stabilization frequency is used to adjust the pressure dependence of the absolute formation rate while Delta(damp) is utilized to control its isotope dependence. The calculations for several isotope combinations of oxygen atoms show a clear dependence of relative formation rates on DeltaZPE. The results are similar to those of Gao and Marcus [J. Chem. Phys. 116, 137 (2002)] obtained within a statistical model. In particular, like in the statistical approach an ad hoc parameter eta approximately 1.14, which effectively reduces the formation rates of the symmetric ABA ozone molecules, has to be introduced in order to obtain good agreement with the measured relative rates of Janssen et al. [Phys. Chem. Chem. Phys. 3, 4718 (2001)]. The temperature dependence of the recombination rate is also addressed.

Femtosecond Raman-Induced Kerr Effect Study of Temperature-Dependent Intermolecular Dynamics in Imidazolium-Based Ionic Liquids: Effects of Anion Species and Cation Alkyl Groups.

PubMed

Kakinuma, Shohei; Ishida, Tateki; Shirota, Hideaki

2017-01-12

The temperature dependence of the intermolecular vibrational dynamics in imidazolium-based ionic liquids (ILs) with 10 different anions was studied by femtosecond Raman-induced Kerr effect spectroscopy. For all ILs investigated in this study, the intensity in the low-frequency region below 50 cm -1 increases, and the spectral density in the high-frequency region above 80 cm -1 decreases (and shows a redshift) with increasing temperature. The first phenomenon would be attributed to the activation of the translational vibrational motions, whereas the second one is ascribed to the slowing librational motion of the imidazolium ring with increasing temperature. Calculated spectra of the density of states for the intermolecular vibrations of 1-butyl-3-methylimidazolium hexafluorophosphate, which is one of the experiment samples studied here, obtained by molecular dynamics simulation agreed well with the experimental results and confirmed the spectral assignments. When we compared the difference spectra between spectra measured at various temperatures and the spectrum measured at 293 K, a clear difference was found in the ∼50 cm -1 region of the Kerr spectra of 1-butyl-3-methylimidazolium thiocyanate and 1-butyl-3-methylimidazolium dicyanamide from those of the other ILs. The difference might have originated from the librational motions of the corresponding anions. We also compared the temperature-dependent Kerr spectra of hexafluorophosphate salts of 1-butyl-3-methylimidazolium, 1-hexyl-3-methylimidazolium, and 1-heptyl-3-methylimidazolium cations. These ILs showed a similar temperature dependence, which was not affected by the alkyl group length. The temperature-dependent viscosities and glass transition temperatures of the ILs were also estimated to determine their fragilities.

Optimized effective potential in real time: Problems and prospects in time-dependent density-functional theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mundt, Michael; Kuemmel, Stephan

2006-08-15

The integral equation for the time-dependent optimized effective potential (TDOEP) in time-dependent density-functional theory is transformed into a set of partial-differential equations. These equations only involve occupied Kohn-Sham orbitals and orbital shifts resulting from the difference between the exchange-correlation potential and the orbital-dependent potential. Due to the success of an analog scheme in the static case, a scheme that propagates orbitals and orbital shifts in real time is a natural candidate for an exact solution of the TDOEP equation. We investigate the numerical stability of such a scheme. An approximation beyond the Krieger-Li-Iafrate approximation for the time-dependent exchange-correlation potential ismore » analyzed.« less

Effects of nicotine on ethanol-induced locomotor sensitization: A model of neuroadaptation.

PubMed

Gubner, Noah R; Phillips, Tamara J

2015-07-15

Co-morbid use of nicotine-containing tobacco products and alcohol (ethanol) is prevalent in young adults initiating use and in alcohol dependent adults, suggesting that these drugs in combination may increase risk to develop dependence on one or both drugs. Neuroadaptations caused by repeated drug exposure are related to the development of drug dependence and vulnerability to relapse. Locomotor sensitization has been used as a behavioral measure used to detect changes in neural drug sensitivity that are thought to contribute to drug dependence and relapse. Locomotor sensitization was measured in the current studies to examine potential differences in the effects of nicotine and ethanol given alone and in combination. Baseline activity levels of DBA/2J mice were assessed on 2 days, then mice were treated for 10 days with saline, nicotine (1 or 2mg/kg of nicotine tartrate), ethanol (1 or 2g/kg), or nicotine plus ethanol and locomotor activity was assessed every third day. On the following day, all mice were challenged with ethanol to measure the expression of sensitization. Mice treated with both nicotine and ethanol exhibited greater stimulation than predicted from the combined independent effects of these drugs, consistent with our previously published results. The combined effects of nicotine and ethanol on locomotor sensitization were dependent on the dose of ethanol and whether testing was performed after the drugs were given together, or after challenge with ethanol alone. These results suggest that nicotine and ethanol in combination can have neuroadaptive effects that differ from the independent effects of these drugs. Published by Elsevier B.V.

Anxiety, affect, self-esteem, and stress: mediation and moderation effects on depression.

PubMed

Nima, Ali Al; Rosenberg, Patricia; Archer, Trevor; Garcia, Danilo

2013-01-01

Mediation analysis investigates whether a variable (i.e., mediator) changes in regard to an independent variable, in turn, affecting a dependent variable. Moderation analysis, on the other hand, investigates whether the statistical interaction between independent variables predict a dependent variable. Although this difference between these two types of analysis is explicit in current literature, there is still confusion with regard to the mediating and moderating effects of different variables on depression. The purpose of this study was to assess the mediating and moderating effects of anxiety, stress, positive affect, and negative affect on depression. Two hundred and two university students (males  = 93, females  = 113) completed questionnaires assessing anxiety, stress, self-esteem, positive and negative affect, and depression. Mediation and moderation analyses were conducted using techniques based on standard multiple regression and hierarchical regression analyses. The results indicated that (i) anxiety partially mediated the effects of both stress and self-esteem upon depression, (ii) that stress partially mediated the effects of anxiety and positive affect upon depression, (iii) that stress completely mediated the effects of self-esteem on depression, and (iv) that there was a significant interaction between stress and negative affect, and between positive affect and negative affect upon depression. The study highlights different research questions that can be investigated depending on whether researchers decide to use the same variables as mediators and/or moderators.

LAURISTON S. TAYLOR LECTURE ON RADIATION PROTECTION AND MEASURMENTS: WHAT MAKES PARTICLE RADIATION SO EFFECTIVE?

PubMed Central

Blakely, Eleanor A.

2012-01-01

The scientific basis for the physical and biological effectiveness of particle radiations has emerged from many decades of meticulous basic research. A diverse array of biologically relevant consequences at the molecular, cellular, tissue, and organism level have been reported, but what are the key processes and mechanisms that make particle radiation so effective, and what competing processes define dose dependences? Recent studies have shown that individual genotypes control radiation-regulated genes and pathways in response to radiations of varying ionization density. The fact that densely ionizing radiations can affect different gene families than sparsely ionizing radiations, and that the effects are dose- and time-dependent has opened up new areas of future research. The complex microenvironment of the stroma, and the significant contributions of the immune response have added to our understanding of tissue-specific differences across the linear energy transfer (LET) spectrum. The importance of targeted vs. nontargeted effects remain a thorny, but elusive and important contributor to chronic low dose radiation effects of variable LET that still needs further research. The induction of cancer is also LET-dependent, suggesting different mechanisms of action across the gradient of ionization density. The focus of this 35th Lauriston S. Taylor Lecture is to chronicle the step-by-step acquisition of experimental clues that have refined our understanding of what makes particle radiation so effective, with emphasis on the example of radiation effects on the crystalline lens of the human eye. PMID:23032880

Nicotine anxiogenic and rewarding effects are decreased in mice lacking beta-endorphin.

PubMed

Trigo, José M; Zimmer, Andreas; Maldonado, Rafael

2009-06-01

The endogenous opioid system plays an important role in the behavioral effects of nicotine. Thus, micro-opioid receptor and the endogenous opioids derived from proenkephalin are involved in the central effects of nicotine. However, the role played by the different endogenous opioid peptides in the acute and chronic effects of nicotine remains to be fully established. Mice lacking beta-endorphin were acutely injected with nicotine at different doses to evaluate locomotor, anxiogenic and antinociceptive responses. The rewarding properties of nicotine were evaluated by using the conditioned place-preference paradigm. Mice chronically treated with nicotine were acutely injected with mecamylamine to study the behavioral expression of nicotine withdrawal. Mice lacking beta-endorphin exhibited a spontaneous hypoalgesia and hyperlocomotion and a reduction on the anxiogenic and rewarding effects induced by nicotine. Nicotine induced similar antinociception and hypolocomotion in both genotypes and no differences were found in the development of physical dependence. The dissociation between nicotine rewarding properties and physical dependence suggests a differential implication of beta-endorphin in these addictive related responses.

Different coding strategies for the perception of stable and changeable facial attributes.

PubMed

Taubert, Jessica; Alais, David; Burr, David

2016-09-01

Perceptual systems face competing requirements: improving signal-to-noise ratios of noisy images, by integration; and maximising sensitivity to change, by differentiation. Both processes occur in human vision, under different circumstances: they have been termed priming, or serial dependencies, leading to positive sequential effects; and adaptation or habituation, which leads to negative sequential effects. We reasoned that for stable attributes, such as the identity and gender of faces, the system should integrate: while for changeable attributes like facial expression, it should also engage contrast mechanisms to maximise sensitivity to change. Subjects viewed a sequence of images varying simultaneously in gender and expression, and scored each as male or female, and happy or sad. We found strong and consistent positive serial dependencies for gender, and negative dependency for expression, showing that both processes can operate at the same time, on the same stimuli, depending on the attribute being judged. The results point to highly sophisticated mechanisms for optimizing use of past information, either by integration or differentiation, depending on the permanence of that attribute.

The N-terminal strand modulates immunoglobulin light chain fibrillogenesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pozo-Yauner, Luis del, E-mail: ldelpozo@inmegen.gob.mx; Wall, Jonathan S.; González Andrade, Martín

2014-01-10

Highlights: •We evaluated the impact of mutations in the N-terminal strand of 6aJL2 protein. •Mutations destabilized the protein in a position-dependent manner. •Destabilizing mutations accelerated the fibrillogenesis by shortening the lag time. •The effect on the kinetic of fibril elongation by seeding was of different nature. •The N-terminal strand is buried in the fibrillar state of 6aJL2 protein. -- Abstract: It has been suggested that the N-terminal strand of the light chain variable domain (V{sub L}) protects the molecule from aggregation by hindering spurious intermolecular contacts. We evaluated the impact of mutations in the N-terminal strand on the thermodynamic stabilitymore » and kinetic of fibrillogenesis of the V{sub L} protein 6aJL2. Mutations in this strand destabilized the protein in a position-dependent manner, accelerating the fibrillogenesis by shortening the lag time; an effect that correlated with the extent of destabilization. In contrast, the effect on the kinetics of fibril elongation, as assessed in seeding experiments was of different nature, as it was not directly dependant on the degree of destabilization. This finding suggests different factors drive the nucleation-dependent and elongation phases of light chain fibrillogenesis. Finally, taking advantage of the dependence of the Trp fluorescence upon environment, four single Trp substitutions were made in the N-terminal strand, and changes in solvent exposure during aggregation were evaluated by acrylamide-quenching. The results suggest that the N-terminal strand is buried in the fibrillar state of 6aJL2 protein. This finding suggest a possible explanation for the modulating effect exerted by the mutations in this strand on the aggregation behavior of 6aJL2 protein.« less

Apple Pollination: Demand Depends on Variety and Supply Depends on Pollinator Identity

PubMed Central

Garratt, M. P. D.; Breeze, T. D.; Boreux, V.; Coston, D. J.; Jenner, N.; Dean, R.; Westbury, D. B.; Biesmeijer, J. C.; Potts, S. G.

2016-01-01

Insect pollination underpins apple production but the extent to which different pollinator guilds supply this service, particularly across different apple varieties, is unknown. Such information is essential if appropriate orchard management practices are to be targeted and proportional to the potential benefits pollinator species may provide. Here we use a novel combination of pollinator effectiveness assays (floral visit effectiveness), orchard field surveys (flower visitation rate) and pollinator dependence manipulations (pollinator exclusion experiments) to quantify the supply of pollination services provided by four different pollinator guilds to the production of four commercial varieties of apple. We show that not all pollinators are equally effective at pollinating apples, with hoverflies being less effective than solitary bees and bumblebees, and the relative abundance of different pollinator guilds visiting apple flowers of different varieties varies significantly. Based on this, the taxa specific economic benefits to UK apple production have been established. The contribution of insect pollinators to the economic output in all varieties was estimated to be £92.1M across the UK, with contributions varying widely across taxa: solitary bees (£51.4M), honeybees (£21.4M), bumblebees (£18.6M) and hoverflies (£0.7M). This research highlights the differences in the economic benefits of four insect pollinator guilds to four major apple varieties in the UK. This information is essential to underpin appropriate investment in pollination services management and provides a model that can be used in other entomolophilous crops to improve our understanding of crop pollination ecology. PMID:27152628

Apple Pollination: Demand Depends on Variety and Supply Depends on Pollinator Identity.

PubMed

Garratt, M P D; Breeze, T D; Boreux, V; Fountain, M T; McKerchar, M; Webber, S M; Coston, D J; Jenner, N; Dean, R; Westbury, D B; Biesmeijer, J C; Potts, S G

2016-01-01

Insect pollination underpins apple production but the extent to which different pollinator guilds supply this service, particularly across different apple varieties, is unknown. Such information is essential if appropriate orchard management practices are to be targeted and proportional to the potential benefits pollinator species may provide. Here we use a novel combination of pollinator effectiveness assays (floral visit effectiveness), orchard field surveys (flower visitation rate) and pollinator dependence manipulations (pollinator exclusion experiments) to quantify the supply of pollination services provided by four different pollinator guilds to the production of four commercial varieties of apple. We show that not all pollinators are equally effective at pollinating apples, with hoverflies being less effective than solitary bees and bumblebees, and the relative abundance of different pollinator guilds visiting apple flowers of different varieties varies significantly. Based on this, the taxa specific economic benefits to UK apple production have been established. The contribution of insect pollinators to the economic output in all varieties was estimated to be £92.1M across the UK, with contributions varying widely across taxa: solitary bees (£51.4M), honeybees (£21.4M), bumblebees (£18.6M) and hoverflies (£0.7M). This research highlights the differences in the economic benefits of four insect pollinator guilds to four major apple varieties in the UK. This information is essential to underpin appropriate investment in pollination services management and provides a model that can be used in other entomolophilous crops to improve our understanding of crop pollination ecology.

THE EFFECT OF A DYNAMIC INNER HELIOSHEATH THICKNESS ON COSMIC-RAY MODULATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Manuel, R.; Ferreira, S. E. S.; Potgieter, M. S., E-mail: rexmanuel@live.com

2015-02-01

The time-dependent modulation of galactic cosmic rays in the heliosphere is studied over different polarity cycles by computing 2.5 GV proton intensities using a two-dimensional, time-dependent modulation model. By incorporating recent theoretical advances in the relevant transport parameters in the model, we showed in previous work that this approach gave realistic computed intensities over a solar cycle. New in this work is that a time dependence of the solar wind termination shock (TS) position is implemented in our model to study the effect of a dynamic inner heliosheath thickness (the region between the TS and heliopause) on the solar modulationmore » of galactic cosmic rays. The study reveals that changes in the inner heliosheath thickness, arising from a time-dependent shock position, does affect cosmic-ray intensities everywhere in the heliosphere over a solar cycle, with the smallest effect in the innermost heliosphere. A time-dependent TS position causes a phase difference between the solar activity periods and the corresponding intensity periods. The maximum intensities in response to a solar minimum activity period are found to be dependent on the time-dependent TS profile. It is found that changing the width of the inner heliosheath with time over a solar cycle can shift the time of when the maximum or minimum cosmic-ray intensities occur at various distances throughout the heliosphere, but more significantly in the outer heliosphere. The time-dependent extent of the inner heliosheath, as affected by solar activity conditions, is thus an additional time-dependent factor to be considered in the long-term modulation of cosmic rays.« less

Attentional Distractor Interference May Be Diminished by Concurrent Working Memory Load in Normal Participants and Traumatic Brain Injury Patients

ERIC Educational Resources Information Center

de Liano, Beatriz Gil-Gomez; Umilta, Carlo; Stablum, Franca; Tebaldi, Francesca; Cantagallo, Anna

2010-01-01

A reduction in congruency effects under working memory (WM) load has been previously described using different attentional paradigms (e.g., Kim, Kim, & Chun, 2005; Smilek, Enns, Eastwood, & Merikle, 2006). One hypothesis is that different types of WM load have different effects on attentional selection, depending on whether a specific memory load…

The effect of thermal processing on microstructure and mechanical properties in a nickel-iron alloy

NASA Astrophysics Data System (ADS)

Yang, Ling

The correlation between processing conditions, resulted microstructure and mechanical properties is of interest in the field of metallurgy for centuries. In this work, we investigated the effect of thermal processing parameters on microstructure, and key mechanical properties to turbine rotor design: tensile yield strength and crack growth resistance, for a nickel-iron based superalloy Inconel 706. The first step of the designing of experiments is to find parameter ranges for thermal processing. Physical metallurgy on superalloys was combined with finite element analysis to estimate variations in thermal histories for a large Alloy 706 forging, and the results were adopted for designing of experiments. Through the systematic study, correlation was found between the processing parameters and the microstructure. Five different types of grain boundaries were identified by optical metallography, fractography, and transmission electron microscopy, and they were found to be associated with eta precipitation at the grain boundaries. Proportions of types of boundaries, eta size, spacing and angle respect to the grain boundary were found to be dependent on processing parameters. Differences in grain interior precipitates were also identified, and correlated with processing conditions. Further, a strong correlation between microstructure and mechanical properties was identified. The grain boundary precipitates affect the time dependent crack propagation resistance, and different types of boundaries have different levels of resistance. Grain interior precipitates were correlated with tensile yield strength. It was also found that there is a strong environmental effect on time dependent crack propagation resistance, and the sensitivity to environmental damage is microstructure dependent. The microstructure with eta decorated on grain boundaries by controlled processing parameters is more resistant to environmental damage through oxygen embrittlement than material without eta phase on grain boundaries. Effort was made to explore the mechanisms of improving the time dependent crack propagation resistance through thermal processing, several mechanisms were identified in both environment dependent and environment independent category, and they were ranked based on their contributions in affecting crack propagation.

The Photorefractive Effect and its Application in Optical Computing

NASA Astrophysics Data System (ADS)

Li, Guo

This Ph.D dissertation includes the fanning effect and the temperature dependence of the diffraction efficiency and response time using different addressing configurations, and evaluation of the limitations and capacity of a holographic storage in BaTiO_3 crystals. Also, we designed a digital holographic optical disk and made an associate memory. The beam fanning effect in a BaTiO_3 crystal was investigated in detail. The effect depends on the crystal faces illuminated. In particular, for the +c face of illumination we found that the fanning effect strongly depends on angle of incidence, polarization and wavelength of the incident light, crystal temperature, laser beam profile, but only weakly depends on input laser power. In the case of the -c face and a-face illumination dependence of the ring angle on wavelength and input power was observed. We found that the intensity of the reflected beam in NDFWM, the intensity of self phase conjugate beam and the response time of the fanning effect decrease with temperature exponentially and there being a major change around 60 ^circ-80^circ C. A random bistability and oscillation of the SPPC occur around 80^circC. We also present a theoretical analysis for the dependence of the photorefractive effect on temperature. We experimentally evaluate the capacity and limitation of optical storage in BaTiO_3 crystals using self-pumped phase conjugation (SPPC) and two-wave mixing. The storage capacity is different with different face of illumination, polarization, beam profile and input power. We demonstrate that using two wave mixing, three dimensional volume holograms can be stored. The information -bearing beam diameter for storage and recall can be about 0.25mm or less. By these techniques we demonstrate that at least 10^5 holograms can be stored in a 3.5 inch photorefractive disk. We evaluate an optimal optical architecture for exploiting the photorefractive effect for digital holographic disk storage. An image with many pixels was used for this experimental evaluation. By using a raytracing program, we traced a beam with a Gaussian profile through our optical system. We also estimated the Seidel aberration of our optical system in order to determine the quality of the stored digital data.

Effect of laser irradiation on the functional activity of enzymes with different structural complexity

NASA Astrophysics Data System (ADS)

Ostrovtsova, Svetlana A.; Volodenkov, Alexander P.; Maskevich, Alexander A.; Artsukevich, Irina M.; Anufrik, Slavomir S.; Makarchikov, Alexander F.; Chernikevich, Ivan P.; Stepuro, Vitali I.

1998-05-01

Three enzymes differing in their structural composition were irradiated by UV lasers to study the effect of temperature, protein concentration and addition of small molecules on their sensitivity to radiation exposure. The laser-induced effects were due to the structural complexity of the protein molecules and depended on the dose applied, the wavelength and the density of irradiation. The multi-enzyme 2- oxoglutarate dehydrogenase complex was subjected to pronounced irradiation-induced changes whereas the response of the two other enzymes was less significant. Reduction of the protein levels in irradiated samples was important under the XeCl laser coercion and the effects depended on the doses applied. The laser irradiation effects are suggested to be realized by means of conformational changes in the protein molecules and intermolecular association- dissociation processes.

Effects of working memory load, a history of conduct disorder, and sex on decision making in substance dependent individuals.

PubMed

Fridberg, Daniel J; Gerst, Kyle R; Finn, Peter R

2013-12-01

Substance dependence and antisocial psychopathology, such as a history of childhood conduct disorder (HCCD), are associated with impulsive or disadvantageous decision making and reduced working memory capacity (WMC). Reducing WMC via a working memory load increases disadvantageous decision making in healthy adults, but no previous studies have examined this effect in young adults with substance dependence and HCCD. Young adults with substance dependence (SubDep; n=158, 71 female), substance dependence and HCCD (SubDep+HCCD; n=72, 24 female), and control participants (n=152, 84 female) completed a test of decision making (the Iowa Gambling Task; IGT) with or without a concurrent working memory load intended to tax WMC. Outcomes were (i) net advantageous decisions on the IGT, and (ii) preferences for infrequent- versus frequent-punishment decks. SubDep+HCCD men made fewer advantageous decisions on the IGT than control men without a load, but there were no group differences among women in that condition. Load was associated with fewer advantageous decisions for SubDep+HCCD women and control men, but not for men or women in the other groups. Participants showed greater preference for infrequent-punishment, advantageous decks under load as well. There are gender differences in the effects of substance dependence, HCCD, and working memory load on decision making on the IGT. Decision making by control men and SubDep+HCCD women suffered the most under load. Load increases preferences for less-frequent punishments, similar to a delay discounting effect. Future research should clarify the cognitive and neural mechanisms underlying these effects. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Effect of in-medium nucleon-nucleon cross section on proton-proton momentum correlation in intermediate-energy heavy-ion collisions

NASA Astrophysics Data System (ADS)

Wang, Ting-Ting; Ma, Yu-Gang; Zhang, Chun-Jian; Zhang, Zheng-Qiao

2018-03-01

The proton-proton momentum correlation function from different rapidity regions is systematically investigated for the Au + Au collisions at different impact parameters and different energies from 400 A MeV to 1500 A MeV in the framework of the isospin-dependent quantum molecular dynamics model complemented by the Lednický-Lyuboshitz analytical method. In particular, the in-medium nucleon-nucleon cross-section dependence of the correlation function is brought into focus, while the impact parameter and energy dependence of the momentum correlation function are also explored. The sizes of the emission source are extracted by fitting the momentum correlation functions using the Gaussian source method. We find that the in-medium nucleon-nucleon cross section obviously influences the proton-proton momentum correlation function, which is from the whole-rapidity or projectile or target rapidity region at smaller impact parameters, but there is no effect on the mid-rapidity proton-proton momentum correlation function, which indicates that the emission mechanism differs between projectile or target rapidity and mid-rapidity protons.

Prey diversity effects on ecosystem functioning depend on consumer identity and prey composition.

PubMed

Wohlgemuth, Daniel; Filip, Joanna; Hillebrand, Helmut; Moorthi, Stefanie D

2017-07-01

Consumer diversity effects on ecosystem functioning are highly context dependent and are determined by consumer specialization and other consumer and prey specific traits such as growth and grazing rates. Despite complex reciprocal interactions between consumers and their prey, few experimental studies have focused on prey diversity effects on consumer dynamics and trophic transfer. In microbial microcosms, we investigated effects of algal prey diversity (one, two and four species) on the production, evenness and grazing rates of 4 ciliate consumers, differing in grazing preferences and rates. Prey diversity increased prey biovolume in the absence of consumers and had opposing effects on different consumers, depending on their specialization and their preferred prey. Consumers profited from prey mixtures compared to monocultures of non-preferred prey, but responded negatively if preferred prey species were offered together with other species. Prey diversity increased consumer evenness by preventing dominance of specific consumers, demonstrating that the loss of prey species may have cascading effects resulting in reduced consumer diversity. Our study emphasizes that not only the degree of specialization but also the selectivity for certain prey species within the dietary niche may alter the consequences of changing prey diversity in a food web context.

Dependency distance distribution - from the perspective of genre variation. Comment on "Dependency distance: a new perspective on syntactic patterns in natural languages" by Haitao Liu et al.

NASA Astrophysics Data System (ADS)

Wang, Yaqin

2017-07-01

Language can be regarded as a system where different components fit together, according to Saussure [1]. Likewise, the central axiom of synergetic linguistic is that language is a self-organized and self-adapting system. One of its main concerns is to view language as ;a psycho-social phenomenon and a biological-cognitive one at the same time; [2, 760]. Based on this assumption, Liu, Xu and Liang propose a novel approach, i.e., dependency distance, to study the general tendency hidden beneath diverse human languages [3]. As the authors describe in sections 1-3, variations within and between human languages all show the similar tendency towards dependency distance minimization (DDM). In sections 4-5, they introduce certain syntactic patterns related to both short and long dependency distances. However, the effect of genre seems to be given less sufficient attention by the authors. A study suggests that different distributions of closeness and degree centralities across genres can broaden the understanding of dependency distance distribution [4]. Another one shows that different genres have different parameters in terms of modeling dependency distance distribution [5]. Further research on the genre variation, therefore, can provide additional support for this issue.

Microbial effects on two tropical soils amended with different types of biochar

NASA Astrophysics Data System (ADS)

Paz, Jorge; Méndez, Ana; Fun, Shenglei; Gascó, Gabriel

2013-04-01

There is an increasing interest in using biochar as soil amendment due to its potential to reduce greenhouse gas emissions from soils and to mitigate heavy metal pollution. In addition, sometimes biochar has been found to increase soil productivity due to its favourable effect on soil aggregation and water holding capacity. However, results obtained can differ greatly depending on the type of biochar utilised. On the other hand, the response of the microbial community to biochar addition is not so well understood. In our experiment we have sampled two soils, differing in their fertility status. A greenhouse pot experiment was established to see the effect of adding four different biochars, differing on their feedstock (Miscanthus, sewage sludge, paper mill waste and pinewood). Additionally, half of the samples excluded soil earthworms, while the other half had 3 individuals of the earthworm Pontoscolex corethrurus. Pots, containing 400 g of soil, were planted with proso millet. Assessed parameters included millet height, soil microbial biomass and soil enzymatic activity related to different biogeochemical cycles (invertase, B-glucosaminidase, B-glucosidase, urease, phosphomonoesterase, arylsulphatase) The effects of biochar on soil biological properties depended on the type of feedstock used for biochar production and pre-existent soil parameters such as soil fertility status. Earthworm presence generally had a positive effect on soil microbial properties.

The Effects of L2 Proficiency Differences in Pairs on Idea Units in a Collaborative Text Reconstruction Task

ERIC Educational Resources Information Center

Shin, Sun-Young; Lidster, Ryan; Sabraw, Stacy; Yeager, Rebecca

2016-01-01

Collaborative text reconstruction tasks such as dictogloss have been suggested as effective second language (L2) learning tasks that promote meaningful interaction between learners and their awareness of L2 target grammatical structures. However, it should be noted that the effect of pair interaction on the final product may differ depending on…

Radiobiological effects of heavy ions and protons. [on cells of mammals, bacteria and viruses

NASA Technical Reports Server (NTRS)

Ryzhov, N. I.; Vorozhtsova, S. V.; Krasavin, Y. A.; Mashinskaya, T. Y.; Savchenko, N. Y.; Fedorov, B. S.; Khlaponina, V. F.; Shelegedin, V. N.; Gut, L.; Sabo, L.

1974-01-01

Radiobiological effects of heavy ions and protons are studied on cells of mammals, bacteria, viruses and DNA of bacteria. Results show that the dose effect dependence bears an exponential character; the reduction of RBE as LET of particle increases reflects the different character of microdistribution of absorbed energy in biological objects with different levels of biological organization.

A Finite-Difference Time-Domain Model of Artificial Ionospheric Modification

NASA Astrophysics Data System (ADS)

Cannon, Patrick; Honary, Farideh; Borisov, Nikolay

Experiments in the artificial modification of the ionosphere via a radio frequency pump wave have observed a wide range of non-linear phenomena near the reflection height of an O-mode wave. These effects exhibit a strong aspect-angle dependence thought to be associated with the process by which, for a narrow range of off-vertical launch angles, the O-mode pump wave can propagate beyond the standard reflection height at X=1 as a Z-mode wave and excite additional plasma activity. A numerical model based on Finite-Difference Time-Domain method has been developed to simulate the interaction of the pump wave with an ionospheric plasma and investigate different non-linear processes involved in modification experiments. The effects on wave propagation due to plasma inhomogeneity and anisotropy are introduced through coupling of the Lorentz equation of motion for electrons and ions to Maxwell’s wave equations in the FDTD formulation, leading to a model that is capable of exciting a variety of plasma waves including Langmuir and upper-hybrid waves. Additionally, discretized equations describing the time-dependent evolution of the plasma fluid temperature and density are included in the FDTD update scheme. This model is used to calculate the aspect angle dependence and angular size of the radio window for which Z-mode excitation occurs, and the results compared favourably with both theoretical predictions and experimental observations. The simulation results are found to reproduce the angular dependence on electron density and temperature enhancement observed experimentally. The model is used to investigate the effect of different initial plasma density conditions on the evolution of non-linear effects, and demonstrates that the inclusion of features such as small field-aligned density perturbations can have a significant influence on wave propagation and the magnitude of temperature and density enhancements.

Introduction to chemistry and applications in nature of mass independent isotope effects special feature.

PubMed

Thiemens, Mark H

2013-10-29

Stable isotope ratio variations are regulated by physical and chemical laws. These rules depend on a relation with mass differences between isotopes. New classes of isotope variation effects that deviate from mass dependent laws, termed mass independent isotope effects, were discovered in 1983 and have a wide range of applications in basic chemistry and nature. In this special edition, new applications of these effects to physical chemistry, solar system origin models, terrestrial atmospheric and biogenic evolution, polar paleo climatology, snowball earth geology, and present day atmospheric sciences are presented.

Fractal Tomlinson model for mesoscopic friction: from microscopic velocity-dependent damping to macroscopic Coulomb friction.

PubMed

Filippov, A E; Popov, V L

2007-02-01

A modified Tomlinson equation with fractal potential is studied. The effective potential is numerically generated and its mesoscopic structure is gradually adjusted to different scales by a number of Fourier modes. It is shown that with the change of scale the intensity of velocity-dependent damping in an effective Langevin equation can be gradually substituted by an equivalent constant "dry friction." For smooth macrosopic surfaces the effective equation completely reduces to the well known Coulomb law.

Solvent dependent photophysical properties of dimethoxy curcumin

NASA Astrophysics Data System (ADS)

Barik, Atanu; Indira Priyadarsini, K.

2013-03-01

Dimethoxy curcumin (DMC) is a methylated derivative of curcumin. In order to know the effect of ring substitution on photophysical properties of curcumin, steady state absorption and fluorescence spectra of DMC were recorded in organic solvents with different polarity and compared with those of curcumin. The absorption and fluorescence spectra of DMC, like curcumin, are strongly dependent on solvent polarity and the maxima of DMC showed red shift with increase in solvent polarity function (Δf), but the above effect is prominently observed in case of fluorescence maxima. From the dependence of Stokes' shift on solvent polarity function the difference between the excited state and ground state dipole moment was estimated as 4.9 D. Fluorescence quantum yield (ϕf) and fluorescence lifetime (τf) of DMC were also measured in different solvents at room temperature. The results indicated that with increasing solvent polarity, ϕf increased linearly, which has been accounted for the decrease in non-radiative rate by intersystem crossing (ISC) processes.

Chiral aldehydes in hydrocarbons: diastereoselective nucleophilic addition, NMR, and CD spectroscopy reveal dynamic solvation effects.

PubMed

Cainelli, Gianfranco; Galletti, Paola; Pieraccini, Silvia; Quintavalla, Arianna; Giacomini, Daria; Piero Spada, Gian

2004-01-01

Temperature-dependent studies on the diastereoselective nucleophilic addition of n- BuLi to alpha-chiral aldehydes as (S)-O-(t-butyl-dimethylsilyl)lactal, (S)-O-(t-butyl-dimethylsilyl) mandelic aldehyde, and (R)-2-phenylpropanal in n-decane and n-dodecane reveal dynamic solvation phenomena with the presence of inversion temperatures (T(inv)) in the Eyring plots of ln (anti/syn) vs. 1/ T. These dynamic solvent effects were disclosed by temperature-dependent studies of the (13)C NMR, CD, and UV spectra of the starting aldehydes in solution of n-decane and n-dodecane. The concomitant presence of three peculiar temperatures T(CD), T(UV), and T(NMR), whose values are identical and match T(inv), clearly confirms our earlier interpretation of the solvent-dependent nature of T(inv). The inversion temperature, as well as T(CD), T(UV), and T(NMR) represents the interconversion temperature of two different solvation clusters which act as two different supramolecules with different stereoselectivities. Copyright 2003 Wiley-Liss, Inc.

Tilt-effect of holograms and images displayed on a spatial light modulator.

PubMed

Harm, Walter; Roider, Clemens; Bernet, Stefan; Ritsch-Marte, Monika

2015-11-16

We show that a liquid crystal spatial light modulator (LCOS-SLM) can be used to display amplitude images, or phase holograms, which change in a pre-determined way when the display is tilted, i.e. observed under different angles. This is similar to the tilt-effect (also called "latent image effect") known from various security elements ("kinegrams") on credit cards or bank notes. The effect is achieved without any specialized optical components, simply by using the large phase shifting capability of a "thick" SLM, which extends over several multiples of 2π, in combination with the angular dependence of the phase shift. For hologram projection one can use the fact that the phase of a monochromatic wave is only defined modulo 2π. Thus one can design a phase pattern extending over several multiples of 2π, which transforms at different readout angles into different 2π-wrapped phase structures, due to the angular dependence of the modulo 2π operation. These different beams then project different holograms at the respective readout angles. In amplitude modulation mode (with inserted polarizer) the intensity of each SLM pixel oscillates over several periods when tuning its control voltage. Since the oscillation period depends on the readout angle, it is possible to find a certain control voltage which produces two (or more) selectable gray levels at a corresponding number of pre-determined readout angles. This is done with all SLM pixels individually, thus constructing different images for the selected angles. We experimentally demonstrate the reconstruction of multiple (Fourier- and Fresnel-) holograms, and of different amplitude images, by readout of static diffractive patterns in a variable angular range between 0° and 60°.

Spin- and Valley-Dependent Electronic Structure in Silicene Under Periodic Potentials

NASA Astrophysics Data System (ADS)

Lu, Wei-Tao; Li, Yun-Fang; Tian, Hong-Yu

2018-03-01

We study the spin- and valley-dependent energy band and transport property of silicene under a periodic potential, where both spin and valley degeneracies are lifted. It is found that the Dirac point, miniband, band gap, anisotropic velocity, and conductance strongly depend on the spin and valley indices. The extra Dirac points appear as the voltage potential increases, the critical values of which are different for electron with different spins and valleys. Interestingly, the velocity is greatly suppressed due to the electric field and exchange field, other than the gapless graphene. It is possible to achieve an excellent collimation effect for a specific spin near a specific valley. The spin- and valley-dependent band structure can be used to adjust the transport, and perfect transmissions are observed at Dirac points. Therefore, a remarkable spin and valley polarization is achieved which can be switched effectively by the structural parameters. Importantly, the spin and valley polarizations are greatly enhanced by the disorder of the periodic potential.

beta. -adrenergic relaxation of smooth muscle: differences between cells and tissues

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scheid, C.R.

1987-09-01

The present studies were carried out in an attempt to resolve the controversy about the Na/sup +/ dependence of ..beta..-adrenergic relaxation in smooth muscle. Previous studies on isolated smooth muscle cells from the toad stomach had suggested that at least some of the actions of ..beta..-adrenergic agents, including a stimulatory effect on /sup 45/Ca efflux, were dependent on the presence of a normal transmembrane Na/sup +/ gradient. Studies by other investigators using tissues derived from mammalian sources had suggested that the relaxing effect of ..beta..-adrenergic agents was Na/sup +/ independent. Uncertainty remained as to whether these discrepancies reflected differences betweenmore » cells and tissues or differences between species. Thus, in the present studies, the authors utilized both tissues and cells from the same source, the stomach muscle of the toad Bufo marinus, and assessed the Na/sup +/ dependence of ..beta..-adrenergic relaxation. They found that elimination of a normal Na/sup +/ gradient abolished ..beta..-adrenergic relaxation of isolated cells. In tissues, however, similar manipulations had no effect on relaxation. The reasons for this discrepancy are unclear but do not appear to be attributable to changes in smooth muscle function following enzymatic dispersion. Thus the controversy concerning the mechanisms of ..beta..-adrenergic relaxation may reflect inherent differences between tissues and cells.« less

Comparison of Statistical Approaches Dealing with Time-dependent Confounding in Drug Effectiveness Studies

PubMed Central

Karim, Mohammad Ehsanul; Petkau, John; Gustafson, Paul; Platt, Robert W.; Tremlett, Helen

2017-01-01

In longitudinal studies, if the time-dependent covariates are affected by the past treatment, time-dependent confounding may be present. For a time-to-event response, marginal structural Cox models (MSCMs) are frequently used to deal with such confounding. To avoid some of the problems of fitting MSCM, the sequential Cox approach has been suggested as an alternative. Although the estimation mechanisms are different, both approaches claim to estimate the causal effect of treatment by appropriately adjusting for time-dependent confounding. We carry out simulation studies to assess the suitability of the sequential Cox approach for analyzing time-to-event data in the presence of a time-dependent covariate that may or may not be a time-dependent confounder. Results from these simulations revealed that the sequential Cox approach is not as effective as MSCM in addressing the time-dependent confounding. The sequential Cox approach was also found to be inadequate in the presence of a time-dependent covariate. We propose a modified version of the sequential Cox approach that correctly estimates the treatment effect in both of the above scenarios. All approaches are applied to investigate the impact of beta-interferon treatment in delaying disability progression in the British Columbia Multiple Sclerosis cohort (1995 – 2008). PMID:27659168

Comparison of statistical approaches dealing with time-dependent confounding in drug effectiveness studies.

PubMed

Karim, Mohammad Ehsanul; Petkau, John; Gustafson, Paul; Platt, Robert W; Tremlett, Helen

2018-06-01

In longitudinal studies, if the time-dependent covariates are affected by the past treatment, time-dependent confounding may be present. For a time-to-event response, marginal structural Cox models are frequently used to deal with such confounding. To avoid some of the problems of fitting marginal structural Cox model, the sequential Cox approach has been suggested as an alternative. Although the estimation mechanisms are different, both approaches claim to estimate the causal effect of treatment by appropriately adjusting for time-dependent confounding. We carry out simulation studies to assess the suitability of the sequential Cox approach for analyzing time-to-event data in the presence of a time-dependent covariate that may or may not be a time-dependent confounder. Results from these simulations revealed that the sequential Cox approach is not as effective as marginal structural Cox model in addressing the time-dependent confounding. The sequential Cox approach was also found to be inadequate in the presence of a time-dependent covariate. We propose a modified version of the sequential Cox approach that correctly estimates the treatment effect in both of the above scenarios. All approaches are applied to investigate the impact of beta-interferon treatment in delaying disability progression in the British Columbia Multiple Sclerosis cohort (1995-2008).

Range compensation for backscattering measurements in the difference-frequency nearfield of a parametric sonar.

PubMed

Foote, Kenneth G

2012-05-01

Measurement of acoustic backscattering properties of targets requires removal of the range dependence of echoes. This process is called range compensation. For conventional sonars making measurements in the transducer farfield, the compensation removes effects of geometrical spreading and absorption. For parametric sonars consisting of a parametric acoustic transmitter and a conventional-sonar receiver, two additional range dependences require compensation when making measurements in the nonlinearly generated difference-frequency nearfield: an apparently increasing source level and a changing beamwidth. General expressions are derived for range compensation functions in the difference-frequency nearfield of parametric sonars. These are evaluated numerically for a parametric sonar whose difference-frequency band, effectively 1-6 kHz, is being used to observe Atlantic herring (Clupea harengus) in situ. Range compensation functions for this sonar are compared with corresponding functions for conventional sonars for the cases of single and multiple scatterers. Dependences of these range compensation functions on the parametric sonar transducer shape, size, acoustic power density, and hydrography are investigated. Parametric range compensation functions, when applied with calibration data, will enable difference-frequency echoes to be expressed in physical units of volume backscattering, and backscattering spectra, including fish-swimbladder-resonances, to be analyzed.

Double inverse-weighted estimation of cumulative treatment effects under nonproportional hazards and dependent censoring.

PubMed

Schaubel, Douglas E; Wei, Guanghui

2011-03-01

In medical studies of time-to-event data, nonproportional hazards and dependent censoring are very common issues when estimating the treatment effect. A traditional method for dealing with time-dependent treatment effects is to model the time-dependence parametrically. Limitations of this approach include the difficulty to verify the correctness of the specified functional form and the fact that, in the presence of a treatment effect that varies over time, investigators are usually interested in the cumulative as opposed to instantaneous treatment effect. In many applications, censoring time is not independent of event time. Therefore, we propose methods for estimating the cumulative treatment effect in the presence of nonproportional hazards and dependent censoring. Three measures are proposed, including the ratio of cumulative hazards, relative risk, and difference in restricted mean lifetime. For each measure, we propose a double inverse-weighted estimator, constructed by first using inverse probability of treatment weighting (IPTW) to balance the treatment-specific covariate distributions, then using inverse probability of censoring weighting (IPCW) to overcome the dependent censoring. The proposed estimators are shown to be consistent and asymptotically normal. We study their finite-sample properties through simulation. The proposed methods are used to compare kidney wait-list mortality by race. © 2010, The International Biometric Society.

Direct observation of temperature-driven magnetic symmetry transitions by vectorial resolved MOKE magnetometry

NASA Astrophysics Data System (ADS)

Cuñado, Jose Luis F.; Pedrosa, Javier; Ajejas, Fernando; Perna, Paolo; Miranda, Rodolfo; Camarero, Julio

2017-10-01

Angle- and temperature-dependent vectorial magnetometry measurements are necessary to disentangle the effective magnetic symmetry in magnetic nanostructures. Here we present a detailed study on an Fe(1 0 0) thin film system with competing collinear biaxial (four-fold symmetry) and uniaxial (two-fold) magnetic anisotropies, carried out with our recently developed full angular/broad temperature range/vectorial-resolved magneto-optical Kerr effect magnetometer, named TRISTAN. The data give direct views on the angular and temperature dependence of the magnetization reversal pathways, from which characteristic axes, remanences, critical fields, domain wall types, and effective magnetic symmetry are obtained. In particular, although the remanence shows four-fold angular symmetry for all investigated temperatures (15 K-400 K), the critical fields show strong temperature and angular dependencies and the reversal mechanism changes for specific angles at a given (angle-dependent) critical temperature, showing signatures of an additional collinear two-fold symmetry. This symmetry-breaking is more relevant as temperature increases to room temperature. It originates from the competition between two anisotropy contributions with different symmetry and temperature evolution. The results highlight the importance of combining temperature and angular studies, and the need to look at different magnetic parameters to unravel the underlying magnetic symmetries and temperature evolutions of the symmetry-breaking effects in magnetic nanostructures.

Cooperative effect of pH-dependent ion transport within two symmetric-structured nanochannels.

PubMed

Meng, Zheyi; Chen, Yang; Li, Xiulin; Xu, Yanglei; Zhai, Jin

2015-04-15

A novel and simple design is introduced to construct bichannel nanofluid diodes by combining two poly(ethylene terephthalate) (PET) films with columnar nanochannel arrays varying in size or in surface charge. This type of bichannel device performs obvious ion current rectification, and the pH-dependent tunability and degree of rectification can be improved by histidine modification. The origin of the ion current rectification and its pH-dependent tunability are attributed to the cooperative effect of the two columnar half-channels and the applied bias on the mobile ions. As a result of surface groups on the bichannel being charged with different polarities or degrees at different pH values, the function of the bichannel device can be converted from a nanofluid diode to a normal nanochannel or to a reverse diode.

Developmentally-regulated sodium channel subunits are differentially sensitive to {alpha}-cyano containing pyrethroids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meacham, Connie A.; Brodfuehrer, Peter D.; Watkins, Jennifer A.

2008-09-15

Juvenile rats have been reported to be more sensitive to the acute neurotoxic effects of the pyrethroid deltamethrin than adults. While toxicokinetic differences between juveniles and adults are documented, toxicodynamic differences have not been examined. Voltage-gated sodium channels, the primary targets of pyrethroids, are comprised of {alpha} and {beta} subunits, each of which have multiple isoforms that are expressed in a developmentally-regulated manner. To begin to test whether toxicodynamic differences could contribute to age-dependent deltamethrin toxicity, deltamethrin effects were examined on sodium currents in Xenopus laevis oocytes injected with different combinations of rat {alpha} (Na{sub v}1.2 or Na{sub v}1.3) andmore » {beta} ({beta}{sub 1} or {beta}{sub 3}) subunits. Deltamethrin induced tail currents in all isoform combinations and increased the percent of modified channels in a concentration-dependent manner. Effects of deltamethrin were dependent on subunit combination; Na{sub v}1.3-containing channels were modified to a greater extent than were Na{sub v}1.2-containing channels. In the presence of a {beta} subunit, deltamethrin effects were significantly greater, an effect most pronounced for Na{sub v}1.3 channels; Na{sub v}1.3/{beta}{sub 3} channels were more sensitive to deltamethrin than Na{sub v}1.2/{beta}{sub 1} channels. Na{sub v}1.3/{beta}{sub 3} channels are expressed embryonically, while the Na{sub v}1.2 and {beta}{sub 1} subunits predominate in adults, supporting the hypothesis for age-dependent toxicodynamic differences. Structure-activity relationships for sensitivity of these subunit combinations were examined for other pyrethroids. Permethrin and tetramethrin did not modify currents mediated by either subunit combination. Cypermethrin, {beta}-cyfluthrin, esfenvalerate and fenpropathrin all modified sodium channel function; effects were significantly greater on Na{sub v}1.3/{beta}{sub 3} than on Na{sub v}1.2/{beta}{sub 1} channels. These data demonstrate a greater sensitivity of Na{sub v}1.3 vs Na{sub v}1.2 channels to deltamethrin and other cyano-containing pyrethroids, particularly in the presence of a {beta} subunit.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

MIchael A. Pope

Six early cores of the MASURCA R-Z program were modeled using ERANOS 2.1. These cores were designed such that their neutron spectra would be similar to that of an oxide-fueled sodium-cooled fast reactor, some containing enriched uranium and others containing depleted uranium and plutonium. Effects of modeling assumptions and solution methods both in ECCO lattice calculations and in BISTRO Sn flux solutions were evaluated using JEFF-3.1 cross-section libraries. Reactivity effects of differences between JEFF-3.1 and ENDF/B-VI.8 were also quantified using perturbation theory analysis. The most important nuclide with respect to reactivity differences between cross-section libraries was 23Na, primarily a resultmore » of differences in the angular dependence of elastic scattering which is more forward-peaked in ENDF/B-VI.8 than in JEFF-3.1. Differences in 23Na inelastic scattering cross-sections between libraries also generated significant differences in reactivity, more due to the differences in magnitude of the cross-sections than the angular dependence. The nuclide 238U was also found to be important with regard to reactivity differences between the two libraries mostly due to a large effect of inelastic scattering differences and two smaller effects of elastic scattering and fission cross-sections. In the cores which contained plutonium, 239Pu fission cross-section differences contributed significantly to the reactivity differences between libraries.« less

Localization and delocalization of a one-dimensional system coupled with the environment

NASA Astrophysics Data System (ADS)

Zhu, Hong-Jun; Xiong, Shi-Jie

2010-03-01

We investigate several models of a one-dimensional chain coupling with surrounding atoms to elucidate disorder-induced delocalization in quantum wires, a peculiar behaviour against common wisdom. We show that the localization length is enhanced by disorder of side sites in the case of strong disorder, but in the case of weak disorder there is a plateau in this dependence. The above behaviour is the conjunct influence of the coupling to the surrounding atoms and the antiresonant effect. We also discuss different effects and their physical origin of different types of disorder in such systems. The numerical results show that coupling with the surrounding atoms can induce either the localization or delocalization effect depending on the values of parameters.

Doppler-resolved kinetics of saturation recovery

DOE PAGES

Forthomme, Damien; Hause, Michael L.; Yu, Hua -Gen; ...

2015-04-08

Frequency modulated laser transient absorption has been used to monitor the ground state rotational energy transfer rates of CN radicals in a double-resonance, depletion recovery experiment. When a pulsed laser is used to burn a hole in the equilibrium ground state population of one rotational state without velocity selection, the population recovery rate is found to depend strongly on the Doppler detuning of a narrow-band probe laser. Similar effects should be apparent for any relaxation rate process that competes effectively with velocity randomization. Alternative methods of extracting thermal rate constants in the presence of these non-thermal conditions are evaluated. Totalmore » recovery rate constants, analogous to total removal rate constants in an experiment preparing a single initial rotational level, are in good agreement with quantum scattering calculations, but are slower than previously reported experiments and show qualitatively different rotational state dependence between Ar and He collision partners. As a result, quasi-classical trajectory studies confirm that the differing rotational state dependence is primarily a kinematic effect.« less

Effects of nuclear structure in the spin-dependent scattering of weakly interacting massive particles

NASA Astrophysics Data System (ADS)

Nikolaev, M. A.; Klapdor-Kleingrothaus, H. V.

1993-06-01

We present calculations of the nuclear from factors for spin-dependent elastic scattering of dark matter WIMPs from123Te and131Xe isotopes, proposed to be used for dark matter detection. A method based on the theory of finite Fermi systems was used to describe the reduction of the single-particle spin-dependent matrix elements in the nuclear medium. Nucleon single-particle states were calculated in a realistic shell model potential; pairing effects were treated within the BCS model. The coupling of the lowest single-particle levels in123Te to collective 2+ excitations of the core was taken into account phenomenologically. The calculated nuclear form factors are considerably less then the single-particle ones for low momentum transfer. At high momentum transfer some dynamical amplification takes place due to the pion exchange term in the effective nuclear interaction. But as the momentum transfer increases, the difference disappears, the momentum transfer increases and the quenching effect disappears. The shape of the nuclear form factor for the131Xe isotope differs from the one obtained using an oscillator basis.

The effects and measures of auricular acupressure and interactive multimedia for smoking cessation in college students.

PubMed

Yeh, Mei-Ling; Wang, Pei-Lan; Lin, Jaung-Geng; Chung, Mei-Ling

2014-01-01

The earlier one starts to smoke, the more likely it is that one's tobacco use will increase. Either auricular acupressure or multimedia education could improve physiological health status and reduce smoking for young smokers. This study aimed to evaluate the effects of a 10-week auricular acupressure (AA) and interactive multimedia (IM) on smoking cessation in college smokers. A pre- and posttest control research design with two experiments (AA and IM) and one control was used. Thirty-two participants were in each of three groups. A significant difference from pretest to posttest among three groups was exhibited on carbon monoxide (CO), cotinine, and nicotine dependence. Scheffe's post hoc test found significances on CO in the AA between the IM and the control and cotinine and nicotine dependence between the AA and the control. After controlling the covariates, the main effect of the group was no difference in all outcomes. The interventions, especially AA, may contribute to a decrease of CO, cotinine, and nicotine dependence along with the time change. An analysis without controlling influences may overestimate interventional effects.

The Effects and Measures of Auricular Acupressure and Interactive Multimedia for Smoking Cessation in College Students

PubMed Central

Yeh, Mei-Ling; Wang, Pei-Lan; Lin, Jaung-Geng; Chung, Mei-Ling

2014-01-01

The earlier one starts to smoke, the more likely it is that one's tobacco use will increase. Either auricular acupressure or multimedia education could improve physiological health status and reduce smoking for young smokers. This study aimed to evaluate the effects of a 10-week auricular acupressure (AA) and interactive multimedia (IM) on smoking cessation in college smokers. A pre- and posttest control research design with two experiments (AA and IM) and one control was used. Thirty-two participants were in each of three groups. A significant difference from pretest to posttest among three groups was exhibited on carbon monoxide (CO), cotinine, and nicotine dependence. Scheffe's post hoc test found significances on CO in the AA between the IM and the control and cotinine and nicotine dependence between the AA and the control. After controlling the covariates, the main effect of the group was no difference in all outcomes. The interventions, especially AA, may contribute to a decrease of CO, cotinine, and nicotine dependence along with the time change. An analysis without controlling influences may overestimate interventional effects. PMID:24987436

Effects of long-term voluntary exercise on learning and memory processes: dependency of the task and level of exercise.

PubMed

García-Capdevila, Sílvia; Portell-Cortés, Isabel; Torras-Garcia, Meritxell; Coll-Andreu, Margalida; Costa-Miserachs, David

2009-09-14

The effect of long-term voluntary exercise (running wheel) on anxiety-like behaviour (plus maze and open field) and learning and memory processes (object recognition and two-way active avoidance) was examined on Wistar rats. Because major individual differences in running wheel behaviour were observed, the data were analysed considering the exercising animals both as a whole and grouped according to the time spent in the running wheel (low, high, and very-high running). Although some variables related to anxiety-like behaviour seem to reflect an anxiogenic compatible effect, the view of the complete set of variables could be interpreted as an enhancement of defensive and risk assessment behaviours in exercised animals, without major differences depending on the exercise level. Effects on learning and memory processes were dependent on task and level of exercise. Two-way avoidance was not affected either in the acquisition or in the retention session, while the retention of object recognition task was affected. In this latter task, an enhancement in low running subjects and impairment in high and very-high running animals were observed.

Negative Temperature Dependence of Recrystallized Grain Size: Formulation and Experimental Confirmation on Copper

PubMed Central

Elmasry, Mohamed; Liu, Fan; Jiang, Yao; Mao, Ze Ning; Liu, Ying; Wang, Jing Tao

2017-01-01

The catalyzing effect on nucleation of recrystallization from existing grains resulting from previous lower temperature deformation is analyzed, analogous to the size effect of foreign nucleus in heterogeneous nucleation. Analytical formulation of the effective nucleation site for recrystallization leads to a negative temperature dependence of recrystallized grain size of metals. Non-isochronal annealing—where annealing time is set just enough for the completion of recrystallization at different temperatures—is conducted on pure copper after severe plastic deformation. More homogeneous and smaller grains are obtained at higher annealing temperature. The good fit between analytical and experimental results unveils the intrinsic feature of this negative temperature dependence of recrystallized grain size. PMID:28772676

Meta-Analysis of Effect Sizes Reported at Multiple Time Points Using General Linear Mixed Model.

PubMed

Musekiwa, Alfred; Manda, Samuel O M; Mwambi, Henry G; Chen, Ding-Geng

2016-01-01

Meta-analysis of longitudinal studies combines effect sizes measured at pre-determined time points. The most common approach involves performing separate univariate meta-analyses at individual time points. This simplistic approach ignores dependence between longitudinal effect sizes, which might result in less precise parameter estimates. In this paper, we show how to conduct a meta-analysis of longitudinal effect sizes where we contrast different covariance structures for dependence between effect sizes, both within and between studies. We propose new combinations of covariance structures for the dependence between effect size and utilize a practical example involving meta-analysis of 17 trials comparing postoperative treatments for a type of cancer, where survival is measured at 6, 12, 18 and 24 months post randomization. Although the results from this particular data set show the benefit of accounting for within-study serial correlation between effect sizes, simulations are required to confirm these results.

Experiential Learning Methods, Simulation Complexity and Their Effects on Different Target Groups

ERIC Educational Resources Information Center

Kluge, Annette

2007-01-01

This article empirically supports the thesis that there is no clear and unequivocal argument in favor of simulations and experiential learning. Instead the effectiveness of simulation-based learning methods depends strongly on the target group's characteristics. Two methods of supporting experiential learning are compared in two different complex…

Measurement Error Calibration in Mixed-Mode Sample Surveys

ERIC Educational Resources Information Center

Buelens, Bart; van den Brakel, Jan A.

2015-01-01

Mixed-mode surveys are known to be susceptible to mode-dependent selection and measurement effects, collectively referred to as mode effects. The use of different data collection modes within the same survey may reduce selectivity of the overall response but is characterized by measurement errors differing across modes. Inference in sample surveys…

The Effects of Pictorial Complexity and Cognitive Style on Visual Recall Memory.

ERIC Educational Resources Information Center

Jesky, Romaine R.; Berry, Louis H.

The effect of the interaction between cognitive style differences (field dependence/field independence) and various degrees of visual complexity on pictorial recall memory was explored using three sets of visuals in three different formats--line drawing, black and white, and color. The subjects were 86 undergraduate students enrolled in two core…

Evolution of bacterial life-history traits is sensitive to community structure.

PubMed

Ketola, Tarmo; Mikonranta, Lauri; Mappes, Johanna

2016-06-01

Very few studies have experimentally assessed the evolutionary effects of species interactions within the same trophic level. Here we show that when Serratia marcescens evolve in multispecies communities, their growth rate exceeds the growth rate of the bacteria that evolved alone, whereas the biomass yield gets lower. In addition to the community effects per se, we found that few species in the communities caused strong effects on S. marcescens evolution. The results indicate that evolutionary responses (of a focal species) are different in communities, compared to species evolving alone. Moreover, selection can lead to very different outcomes depending on the community structure. Such context dependencies cast doubt on our ability to predict the course of evolution in the wild, where species often inhabit very different kinds of communities. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

The effect of picosecond laser pulses on redox-dependent processes in mice red blood cells studied in vivo

NASA Astrophysics Data System (ADS)

Voronova, Olga; Gening, Tatyana; Abakumova, Tatyana; Sysolyatin, Aleksey; Zolotovskiy, Igor; Antoneeva, Inna; Ostatochnikov, Vladimir; Gening, Snezhanna

2014-02-01

The study highlights the effect of different modes of in vivo laser irradiation of mice using a PFL8LA laser with λ = 1560 nm, pulse duration of 1,4•10-12 s, peak power of 3,72•103 W and average output power of 20•10-3 W on the lipid peroxidation parameters: conjugated dienes, ketodienes and conjugated trienes, malondialdehyde, Schiff bases and the activity of antioxidant enzymes - catalase, glutathione -S-transferase and superoxide dismutase in erythrocytes and plasma of mice. Two groups of mice received a total dose of 3.8 J/cm2 per group, but the 1st group was irradiated only once, while the 2nd - four times. Significant differences in the parameters of the 1st and 2nd groups indicate different effects of the irradiation modes on redox-dependent processes in red blood cells of mice.

The effect of temperature on pinning mechanisms in HTS composites

NASA Astrophysics Data System (ADS)

Sotnikova, A. P.; Rudnev, I. A.

2016-09-01

Pinning mechanism in samples of second generation tapes (2G) of high-temperature superconductors (HTS) was studied The critical current and the pinning force were calculated from the magnetization curves measured in the temperature range of 4.2 - 77 K in magnetic fields up to 14 Tesla using vibration sample magnetometer. To determine the pinning mechanism the dependences of pinning force on magnetic field were constructed according to the Dew-Hughes model and Kramer's rule. The obtained dependences revealed a significant influence of the temperature on effectiveness of different types of pinning. At low temperatures the 2G HTS tapes of different manufacturers demonstrated an equal efficiency of the pinning centers but with temperature increase the differences in pinning mechanisms as well as in properties and effectiveness of the pinning centers become obvious. The influence of the pinning mechanism on the energy losses in HTS tapes was shown.

Photon number dependent group velocity in vacuum induced transparency

NASA Astrophysics Data System (ADS)

Lauk, Nikolai; Fleischhauer, Michael

2015-05-01

Vacuum induced transparency (VIT) is an effect which occurs in an ensemble of three level atoms in a Λ configuration that interact with two quantized fields. Coupling of one transition to a cavity mode induces transparency for the second field on the otherwise opaque transition similar to the well known EIT effect. In the strong coupling regime even an empty cavity leads to transparency, in contrast to EIT where the presence of a strong control field is required. This transparency is accompanied by a reduction of the group velocity for the propagating field. However, unlike in EIT the group velocity in VIT depends on the number of incoming photons, i.e. different photon number components propagate with different velocities. Here we investigate the possibility of using this effect to spatially separate different photon number components of an initially coherent pulse. We present the results of our calculations and discuss a possible experimental realization.

Disruptive effects of light pollution on sleep in free-living birds: Season and/or light intensity-dependent?

PubMed

Raap, Thomas; Sun, Jiachen; Pinxten, Rianne; Eens, Marcel

2017-11-01

Light pollution or artificial light at night (ALAN) is an increasing anthropogenic environmental pollutant posing an important potential threat for wildlife. Evidence of its effects on animal physiology and behaviour is accumulating. However, in order to effectively mitigate light pollution it is important to determine which factors contribute to the severity of effects of ALAN. In this experimental study we explored whether there are seasonal-dependent effects of ALAN on sleep in free-living great tits (Parus major), an important model species. Additionally, we looked at whether light intensity determined the severity of effects of ALAN on sleep. We therefore exposed animals to artificial light inside the nest box (3lx) in December (winter) and February (pre-breeding season). Results from February were compared with the results from a previous study in February, using a lower light intensity (1.6lx). We found little evidence for a season-dependent response. Effects of ALAN hardly differed between high and low light intensity. ALAN disrupted sleep with as main effect a decrease in sleep duration (≈-40min) as animals woke up earlier (≈-24min). However, compared to a natural dark situation sleep onset was delayed by high but not by low light intensity of ALAN. Our study underlines earlier found disruptive effects of ALAN on sleep of free-living animals. While we found no conclusive evidence for seasonal or light intensity-dependent effects of ALAN, additional experimental work using lower light intensities might show such differences. Examining potential management options is crucial in mitigating disruptive effects of light pollution, which will be an important focus for future studies. Copyright © 2017 Elsevier B.V. All rights reserved.

Prediction of pH dependent absorption using in vitro, in silico, and in vivo rat models: Early liability assessment during lead optimization.

PubMed

Saxena, Ajay; Shah, Devang; Padmanabhan, Shweta; Gautam, Shashyendra Singh; Chowan, Gajendra Singh; Mandlekar, Sandhya; Desikan, Sridhar

2015-08-30

Weakly basic compounds which have pH dependent solubility are liable to exhibit pH dependent absorption. In some cases, a subtle change in gastric pH can significantly modulate the plasma concentration of the drug and can lead to sub-therapeutic exposure of the drug. Evaluating the risk of pH dependent absorption and potential drug-drug interaction with pH modulators are important aspects of drug discovery and development. In order to assess the risk around the extent of decrease in the systemic exposure of drugs co-administered with pH modulators in the clinic, a pH effect study is carried out, typically in higher species, mostly dog. The major limitation of a higher species pH effect study is the resource and material requirement to assess this risk. Hence, these studies are mostly restricted to promising or advanced leads. In our current work, we have used in vitro aqueous solubility, in silico simulations using GastroPlus™ and an in vivo rat pH effect model to provide a qualitative assessment of the pH dependent absorption liability. Here, we evaluate ketoconazole and atazanavir with different pH dependent solubility profiles and based on in vitro, in silico and in vivo results, a different extent of gastric pH effect on absorption is predicted. The prediction is in alignment with higher species and human pH effect study results. This in vitro, in silico and in vivo (IVISIV) correlation is then extended to assess pH absorption mitigation strategy. The IVISIV predicts pH dependent absorption for BMS-582949 whereas its solubility enhancing prodrug, BMS-751324 is predicted to mitigate this liability. Overall, the material requirement for this assessment is substantially low which makes this approach more practical to screen multiple compounds during lead optimization. Copyright © 2015 Elsevier B.V. All rights reserved.

Modeling seasonal behavior changes and disease transmission with application to chronic wasting disease.

PubMed

Oraby, Tamer; Vasilyeva, Olga; Krewski, Daniel; Lutscher, Frithjof

2014-01-07

Behavior and habitat of wildlife animals change seasonally according to environmental conditions. Mathematical models need to represent this seasonality to be able to make realistic predictions about the future of a population and the effectiveness of human interventions. Managing and modeling disease in wild animal populations requires particular care in that disease transmission dynamics is a critical consideration in the etiology of both human and animal diseases, with different transmission paradigms requiring different disease risk management strategies. Since transmission of infectious diseases among wildlife depends strongly on social behavior, mechanisms of disease transmission could also change seasonally. A specific consideration in this regard confronted by modellers is whether the contact rate between individuals is density-dependent or frequency-dependent. We argue that seasonal behavior changes could lead to a seasonal shift between density and frequency dependence. This hypothesis is explored in the case of chronic wasting disease (CWD), a fatal disease that affects deer, elk and moose in many areas of North America. Specifically, we introduce a strategic CWD risk model based on direct disease transmission that accounts for the seasonal change in the transmission dynamics and habitats occupied, guided by information derived from cervid ecology. The model is composed of summer and winter susceptible-infected (SI) equations, with frequency-dependent and density-dependent transmission dynamics, respectively. The model includes impulsive birth events with density-dependent birth rate. We determine the basic reproduction number as a weighted average of two seasonal reproduction numbers. We parameterize the model from data derived from the scientific literature on CWD and deer ecology, and conduct global and local sensitivity analyses of the basic reproduction number. We explore the effectiveness of different culling strategies for the management of CWD: although summer culling seems to be an effective disease eradication strategy, the total culling rate is limited by the requirement to preserve the herd. © 2013 Elsevier Ltd. All rights reserved.

Temperature dependence of carrier transport and resistance switching in Pt/SrTi1-xNbxO3 Schottky junctions

NASA Astrophysics Data System (ADS)

Li, Jianyong; Ohashi, Naoki; Okushi, Hideyo; Haneda, Hajime

2011-03-01

We investigated the temperature dependence of carrier transport and resistance switching of Pt/SrTi1-xNbxO3 Schottky junctions in the temperature range 80-400 K by measuring the current-voltage (I-V) characteristics and the frequency dependence of the capacitance-voltage (C-V) characteristics. The I-V curves displayed a high degree of hysteresis, known as the colossal electroresistance (CER) effect, and their temperature dependence showed an anomalous behavior, i.e., the magnitude of the hysteresis increased with decreasing T. The experimental results were analyzed by taking into account the temperature and electric-field dependence of the relative permittivity of SrTi1-xNbxO3 as well as the inhomogeneity of the Schottky barrier height (SBH) (a model in which two parallel current paths coexist in the Schottky barrier). It was confirmed that the observed I-V and C-V curves were well simulated by this model, thus indicating that the CER effects originated in the field emission current through different SBHs and at different locations of the Schottky junctions. Based on these results, we explain the mechanism of the CER effect qualitatively in terms of this model. For this purpose, we take into account the pinched-off effect caused by the small-scale inhomogeneity of SBH and the existence of deep levels as a result of defects and unintentional impurities in the depletion layer of the Pt/SrTi1-xNbxO3 Schottky junctions.

Photon energy dependence of photo-induced inverse spin-Hall effect in Pt/GaAs and Pt/Ge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Isella, Giovanni, E-mail: giovanni.isella@polimi.it; Bottegoni, Federico; Ferrari, Alberto

2015-06-08

We report the photon energy dependence of photo-induced inverse spin Hall effect (ISHE) in Pt/GaAs and Pt/Ge Schottky junctions. The experimental results are compared with a spin drift-diffusion model, which highlights the role played by the different spin lifetime in the two semiconductors, in determining the energy dependence of the ISHE signal detected in the Pt layer. The good qualitative agreement between experiments and modelling indicates that photo-induced ISHE can be used as a tool to characterize spin lifetime in semiconductors.

Effect of the environment on wear ranking and corrosion of biomedical CoCrMo alloys.

PubMed

Muñoz, A Igual; Mischler, S

2011-03-01

The corrosion behaviour and the wear ranking of biomedical high carbon (HC) and low carbon (LC) CoCrMo alloys sliding against an alumina ball in four different simulated body fluids [NaCl and phosphate buffered solutions (PBS) with and without albumin] has been analyzed by tribocorrosion and electrochemical techniques. The effects of alloy and of albumin on corrosion depend on the base electrolyte: differences between LC and HC alloy were only observed in NaCl solutions but not in PBS. Albumin increased significantly corrosion of both alloys in PBS solutions while its effect in NaCl was smaller. The wear ranking of the HC and LC alloys also depends on the environment. In the present study, HC CoCrMo alloy had lower wear resistance in NaCl and PBS + albumin than the LC alloy, while no differences between both alloys were found in the other solutions. This was attributed to surface chemical effects affecting third body behaviour.

Damage and protection of the photosynthetic apparatus from UV-B radiation. II. Effect of quercetin at different pH.

PubMed

Dobrikova, Anelia G; Apostolova, Emilia L

2015-07-20

The effect of the exogenously added quercetin against the UV-B inhibition of the photosystem II (PSII) functions in isolated pea thylakoid membranes suspended at different pH of the medium (6.5, 7.6 and 8.4) was investigated. The data revealed that the interaction of this flavonoid with the membranes depends on the pH and influences the initial S0-S1 state distribution of PSII in the dark, the energy transfer between pigment-protein complexes of the photosynthetic apparatus and the membrane fluidity. Quercetin also displays a different UV-protective effect depending on its location in the membranes, as the effect is more pronounced at pH 8.4 when it is located at the membrane surface. The results suggest that quercetin induces structural changes in thylakoid membranes, one of the possible reasons for its protection of the photosynthetic apparatus. Copyright © 2015 Elsevier GmbH. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, H., E-mail: li-huanglong@mail.tsinghua.edu.cn; Gillen, R.; Robertson, J., E-mail: jr214@cam.ac.uk

The screened exchange (sX) hybrid functional has been widely used in computational material science. Although it has widely been studied in bulk systems, less is known about its functional behavior in surface systems which are crucial to many technologies such as materials synthesis and nano-electronic devices. Assessing the screening dependent functional behaviors in the surface systems is therefore important for its application in such systems. In this work, we investigate the screening effects of the sX in CO adsorption on Pt(111) surface. The differences between the sX and Heyd-Scuseria-Ernzerhof (HSE06) hybrid functionals, and the effects of screening parameters are studied.more » The screening has two effects: first, the HOMO-LUMO gap is screening dependent. This affects the site preference most significantly. In this work, atop adsorption of CO/Pt(111) is predicted by the hybrid functionals with screened exchange potential. The sX(1.44) gives the largest HOMO-LUMO gap for the isolated CO molecule. The adsorption energy difference between the atop and fcc site is also the largest by the sX(1.44) which is explained by the reduced metal d states to the CO 2π* state back-donation, with stronger effect for the fcc adsorption than for the atop adsorption; second, the adsorption energy is screening dependent. This can be seen by comparing the sX(2.38) and HSE06 which have different screening strengths. They show similar surface band structures for the CO adsorption but different adsorption energies, which is explained by the stronger CO 5σ state to the metal d states donation or the effectively screened Pauli repulsion. This work underlines the screening strength as a main difference between sX and HSE06, as well as an important hybrid functional parameter for surface calculation.« less

Dose- and time-dependence of the host-mediated response to paclitaxel therapy: a mathematical modeling approach.

PubMed

Benguigui, Madeleine; Alishekevitz, Dror; Timaner, Michael; Shechter, Dvir; Raviv, Ziv; Benzekry, Sebastien; Shaked, Yuval

2018-01-05

It has recently been suggested that pro-tumorigenic host-mediated processes induced in response to chemotherapy counteract the anti-tumor activity of therapy, and thereby decrease net therapeutic outcome. Here we use experimental data to formulate a mathematical model describing the host response to different doses of paclitaxel (PTX) chemotherapy as well as the duration of the response. Three previously described host-mediated effects are used as readouts for the host response to therapy. These include the levels of circulating endothelial progenitor cells in peripheral blood and the effect of plasma derived from PTX-treated mice on migratory and invasive properties of tumor cells in vitro . A first set of mathematical models, based on basic principles of pharmacokinetics/pharmacodynamics, did not appropriately describe the dose-dependence and duration of the host response regarding the effects on invasion. We therefore provide an alternative mathematical model with a dose-dependent threshold, instead of a concentration-dependent one, that describes better the data. This model is integrated into a global model defining all three host-mediated effects. It not only precisely describes the data, but also correctly predicts host-mediated effects at different doses as well as the duration of the host response. This mathematical model may serve as a tool to predict the host response to chemotherapy in cancer patients, and therefore may be used to design chemotherapy regimens with improved therapeutic outcome by minimizing host mediated effects.

Carrier Propagation Dependence on Applied Potentials in Pentacene Organic Field Effect Transistors Investigated by Impedance Spectroscopy and Electrical Time-of-Flight Techniques

NASA Astrophysics Data System (ADS)

Lin, Jack; Weis, Martin; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa

2011-04-01

Transient measurements of impedance spectroscopy and electrical time-of-flight (TOF) techniques were used for the evaluation of carrier propagation dependence on applied potentials in a pentacene organic field effect transistor (OFET). These techniques are based on carrier propagation, thus isolates the effect of charge density. The intrinsic mobility which is free from contact resistance effects was obtained by measurement of various channel lengths. The obtained intrinsic mobility shows good correspondence with steady-state current-voltage measurement's saturation mobility. However, their power law relations on mobility vs applied potential resulted in different exponents, suggesting different carrier propagation mechanisms, which is attributable to filling of traps or space charge field in the channel region. The hypothesis was verified by a modified electrical TOF experiment which demonstrated how the accumulated charges in the channel influence the effective mobility.

Effects of interaction between temperature conditions and copper exposure on immune defense and other life-history traits of the blow fly Protophormia terraenovae.

PubMed

Pölkki, Mari; Kangassalo, Katariina; Rantala, Markus J

2014-01-01

Environmental pollution is considered one of the major threats to organisms. Direct effects of heavy metal pollution on various life-history traits are well recognized, while the effects of potential interactions between two distinct environmental conditions on different traits are poorly understood. Here, we have tested the effects of interactions between temperature conditions and heavy metal exposure on innate immunity and other life-history traits. Maggots of the blow fly Protophormia terraenovae were reared on either copper-contaminated or uncontaminated food, under three different temperature environments. Encapsulation response, body mass, and development time were measured for adult flies that were not directly exposed to copper. We found that the effects of copper exposure on immunity and other traits are temperature-dependent, suggesting that the ability to regulate toxic compounds in body tissues might depend on temperature conditions. Furthermore, we found that temperature has an effect on sex differences in immune defense. Males had an encapsulation response at higher temperatures stronger than that of females. Our results indicate that the effects of environmental conditions on different traits are much more intricate than what can be predicted. This is something that should be considered when conducting immunological experiments or comparing results of previous studies.

Propagation of Love waves with surface effects in an electrically-shorted piezoelectric nanofilm on a half-space elastic substrate.

PubMed

Zhang, Sijia; Gu, Bin; Zhang, Hongbin; Feng, Xi-Qiao; Pan, Rongying; Alamusi; Hu, Ning

2016-03-01

The propagation of Love waves in the structure consisting of a nanosized piezoelectric film and a semi-infinite elastic substrate is investigated in the present paper with the consideration of surface effects. In our analysis, surface effects are taken into account in terms of the surface elasticity theory and the electrically-shorted conditions are adopted on the free surface of the piezoelectric film and the interface between the film and the substrate. This work focuses on the new features in the dispersion relations of different modes due to surface effects. It is found that with the existence of surface effects, the frequency dispersion of Love waves shows the distinct dependence on the thickness and the surface constants when the film thickness reduces to nanometers. In general, phase velocities of all dispersion modes increase with the decrease of the film thickness and the increase of the surface constants. However, surface effects play different functions in the frequency dispersions of different modes, especially for the first mode dispersion. Moreover, different forms of Love waves are observed in the first mode dispersion, depending on the presence of the surface effects on the surface and the interface. Copyright © 2015 Elsevier B.V. All rights reserved.

Identifying Key Features of Effective Active Learning: The Effects of Writing and Peer Discussion

PubMed Central

Pangle, Wiline M.; Wyatt, Kevin H.; Powell, Karli N.; Sherwood, Rachel E.

2014-01-01

We investigated some of the key features of effective active learning by comparing the outcomes of three different methods of implementing active-learning exercises in a majors introductory biology course. Students completed activities in one of three treatments: discussion, writing, and discussion + writing. Treatments were rotated weekly between three sections taught by three different instructors in a full factorial design. The data set was analyzed by generalized linear mixed-effect models with three independent variables: student aptitude, treatment, and instructor, and three dependent (assessment) variables: change in score on pre- and postactivity clicker questions, and coding scores on in-class writing and exam essays. All independent variables had significant effects on student performance for at least one of the dependent variables. Students with higher aptitude scored higher on all assessments. Student scores were higher on exam essay questions when the activity was implemented with a writing component compared with peer discussion only. There was a significant effect of instructor, with instructors showing different degrees of effectiveness with active-learning techniques. We suggest that individual writing should be implemented as part of active learning whenever possible and that instructors may need training and practice to become effective with active learning. PMID:25185230

Dose-Dependent and Lasting Influences of Intranasal Vasopressin on Face Processing in Men

PubMed Central

Price, Daniel; Burris, Debra; Cloutier, Anna; Thompson, Carol B.; Rilling, James K.; Thompson, Richmond R.

2017-01-01

Arginine vasopressin (AVP) and related peptides have diverse effects on social behaviors in vertebrates, sometimes promoting affiliative interactions and sometimes aggressive or antisocial responses. The type of influence, in at least some species, depends on social contexts, including the sex of the individuals in the interaction and/or on the levels of peptide within brain circuits that control the behaviors. To determine if AVP promotes different responses to same- and other-sex faces in men, and if those effects are dose dependent, we measured the effects of two doses of AVP on subjective ratings of male and female faces. We also tested if any influences persist beyond the time of drug delivery. When AVP was administered intranasally on an initial test day, 20 IU was associated with decreased social assessments relative to placebo and 40 IU, and some of the effects persisted beyond the initial drug delivery and appeared to generalize to novel faces on subsequent test days. In single men, those influences were most pronounced, but not exclusive, for male faces, whereas in coupled men they were primarily associated with responses to female faces. Similar influences were not observed if AVP was delivered after placebo on a second test day. In a preliminary analysis, the differences in social assessments observed between men who received 20 and 40 IU, which we suggest primarily reflect lowered social assessments induced by the lower dose, appeared most pronounced in subjects who carry what has been identified as a risk allele for the V1a receptor gene. Together, these results suggest that AVP’s effects on face processing, and possibly other social responses, differ according to dose, depend on relationship status, and may be more prolonged than previously recognized. PMID:29018407

Effect of difference of cupula and endolymph densities on the dynamics of semicircular canal.

PubMed

Kondrachuk, A V; Sirenko, S P; Boyle, R

2008-01-01

The effect of different densities of a cupula and endolymph on the dynamics of the semicircular canals is considered within the framework of a simplified one-dimensional mathematical model where the canal is approximated by a torus. If the densities are equal, the model is represented by Steinhausen's phenomenological equation. The difference of densities results in the complex dynamics of the cupulo-endolymphatic system, and leads to a dependence on the orientation of both the gravity vector relative to the canal plane and the axis of rotation, as well as on the distance between the axis of rotation and the center of the semicircular canal. Our analysis focused on two cases of canal stimulation: rotation with a constant velocity and a time-dependent (harmonically oscillating) angular velocity. Two types of spatial orientation of the axis of rotation, the axis of canal symmetry, and the vector of gravity were considered: i) the gravity vector and axis of rotation lie in the canal plane, and ii) the axis of rotation and gravity vector are normal to the canal plane. The difference of the cupula and endolymph densities reveals new features of cupula dynamics, for instance--a shift of the cupula to a new position of equilibrium that depends on the gravity vector and the parameters of head rotation, and the onset of cupula oscillations with multiple frequencies that results in the distortion of cupula dynamics relative to harmonic stimulation. Factors that might influence the density difference effects and the conditions under which these effects occur are discussed.

Contrasting gender differences on two measures of exercise dependence.

PubMed

Weik, M; Hale, B D

2009-03-01

Recent studies using multidimensional measures have shown that men (Exercise Dependence Scale; EDS-R) are more exercise-dependent than women, whereas others have found that women (Exercise Dependence Questionnaire; EDQ) are more exercise-dependent than men. This study investigated whether there may be sex differences in exercise dependence or whether the questionnaires may be measuring different dimensions of exercise dependence. Regular exercisers voluntarily completed the EDS-R, EDQ and Drive for Thinness (DFT) subscale before or after a workout. A local health club in the eastern USA. Male (n = 102) and female (n = 102) exercisers completed the three questionnaires, but 11 participants (1 man, 10 women) were excluded from further analysis because scores indicated possible secondary exercise dependence (eating disorder). Eight subscales of the EDQ, seven subscales of the EDS, the DFT subscale, and several demographic variables served as dependent measures. A multivariate analysis of variance (MANOVA) on the EDS-R showed that men were significantly higher than women on the Withdrawal, Continuance, Tolerance, Lack of Control, Time, and Intention Effect subscales. Another MANOVA on the EDQ indicated that women scored significantly higher than did men on the Interference, Positive Rewards, Withdrawal, and Social Reasons subscales. Statistical analysis using t tests revealed that men had significantly higher total EDS-R scores than women, but women had significantly higher EDQ and DFT scores. These results suggest that both questionnaires measure different aspects of exercise dependence that favour either gender. It remains for further research to determine whether these instruments are equally viable for measurement of ED in both men and women.

Presynaptic control of dopamine release by BETA-phenylethylamine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zharikova, A.D.; Godukhin, O.V.

The authors study the effect of extracellular ions (Ca/sup 2 +/, Na/sup 2 +/) on the beta-phenylethylamine (beta-PEA) releasing effect, dependence of this effect on the membrane potential of dopaminergic endings, and the participation of dopamine presynaptic autoreceptors in the realization of the effects of beta-PEA on dopamine (DA) release. Experi ments were carried out on noninbred male albino rats. By means of a microsyringe, (/sup 3/H)-DA hydrochloride was injected. The significance of the difference in levels of (/sup 3/H)-DA release during analogous periods of perfusion in the groups of animals compared was estimated by Student's test. These experiments inmore » vivo thus demonstrated the ability of beta-PEA to regulate DA release in different directions depending on the functional state of the dopaminergic neuron.« less

Anxiety, Affect, Self-Esteem, and Stress: Mediation and Moderation Effects on Depression

PubMed Central

Nima, Ali Al; Rosenberg, Patricia; Archer, Trevor; Garcia, Danilo

2013-01-01

Background Mediation analysis investigates whether a variable (i.e., mediator) changes in regard to an independent variable, in turn, affecting a dependent variable. Moderation analysis, on the other hand, investigates whether the statistical interaction between independent variables predict a dependent variable. Although this difference between these two types of analysis is explicit in current literature, there is still confusion with regard to the mediating and moderating effects of different variables on depression. The purpose of this study was to assess the mediating and moderating effects of anxiety, stress, positive affect, and negative affect on depression. Methods Two hundred and two university students (males  = 93, females  = 113) completed questionnaires assessing anxiety, stress, self-esteem, positive and negative affect, and depression. Mediation and moderation analyses were conducted using techniques based on standard multiple regression and hierarchical regression analyses. Main Findings The results indicated that (i) anxiety partially mediated the effects of both stress and self-esteem upon depression, (ii) that stress partially mediated the effects of anxiety and positive affect upon depression, (iii) that stress completely mediated the effects of self-esteem on depression, and (iv) that there was a significant interaction between stress and negative affect, and between positive affect and negative affect upon depression. Conclusion The study highlights different research questions that can be investigated depending on whether researchers decide to use the same variables as mediators and/or moderators. PMID:24039896

Silica nanoparticles and biological dispersants: genotoxic effects on A549 lung epithelial cells

NASA Astrophysics Data System (ADS)

Brown, David M.; Varet, Julia; Johnston, Helinor; Chrystie, Alison; Stone, Vicki

2015-10-01

Silica nanoparticle exposure could be intentional (e.g. medical application or food) or accidental (e.g. occupational inhalation). On entering the body, particles become coated with specific proteins depending on the route of entry. The ability of silica particles of different size and charge (non-functionalized 50 and 200 nm and aminated 50 and 200 nm) to cause genotoxic effects in A549 lung epithelial cells was investigated. Using the modified comet assay and the micronucleus assay, we examined the effect of suspending the particles in different dispersion media [RPMI or Hanks' balanced salt solution (HBSS), supplemented with bovine serum albumin (BSA), lung lining fluid (LLF) or serum] to determine if this influenced the particle's activity. Particle characterisation suggested that the particles were reasonably well dispersed in the different media, with the exception of aminated 50 nm particles which showed evidence of agglomeration. Plain 50, 200 nm and aminated 50 nm particles caused significant genotoxic effects in the presence of formamidopyrimidine-DNA glycosylase when dispersed in HBSS or LLF. These effects were reduced when the particles were dispersed in BSA and serum. There was no significant micronucleus formation produced by any of the particles when suspended in any of the dispersants. The data suggest that silica particles can produce a significant genotoxic effect according to the comet assay in A549 cells, possibly driven by an oxidative stress-dependent mechanism which may be modified depending on the choice of dispersant employed.

Dependence of CdTe response of bias history

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sites, J.R.; Sasala, R.A.; Eisgruber, I.L.

1995-11-01

Several time-dependent effect have been observed in CdTe cells and modules in recent years. Some appear to be related to degradation at the back contact, some to changes in temperature at the thin-film junction, and some to the bias history of the cell or module. Back-contact difficulties only occur in some cases, and the other two effects are reversible. Nevertheless, confusion in data interpretation can arise when these effects are not characterized. This confusion can be particularly acute when more than one time-dependent effect occurs during the same measurement cycle. The purpose of this presentation is to help categorize time-dependentmore » effects in CdTe and other thin-film cells to elucidate those related to bias history, and to note differences between cell and module analysis.« less

Time-Driven Effects on Processing Relative Clauses

ERIC Educational Resources Information Center

Schremm, Andrea; Horne, Merle; Roll, Mikael

2016-01-01

The present response time study investigated how a hypothesized time-based working memory constraint of 2-3 s affects the resolution of grammatical and semantic dependencies. Congruent and incongruent object relative (OR) and subject relative sentences were read at different presentation rates so that the distance between dependent words was…

Study of the effect of electron irradiation on the density of the activated sludge in aqueous solution

NASA Astrophysics Data System (ADS)

Kupchishin, A. I.; Niyazov, M. N.; Taipova, B. G.; Voronova, N. A.; Khodarina, N. N.

2018-01-01

Complex experimental studies on the effect of electron irradiation on the deposition rate of active sludge in aqueous systems by the optical method have been carried out. The obtained dependences of density (ρ) on time (t) are of the same nature for different radiation sources. The experimental curves of the dependence of the active sludge density on time are satisfactorily described by an exponential model.

Impact of divalent metal ions on regulation of adenylyl cyclase isoforms by forskolin analogs.

PubMed

Erdorf, Miriam; Mou, Tung-Chung; Seifert, Roland

2011-12-01

Mammalian membranous adenylyl cyclases (mACs) play an important role in transmembrane signalling events in almost every cell and represent an interesting drug target. Forskolin (FS) is an invaluable research tool, activating AC isoforms 1-8. However, there is a paucity of AC isoform-selective FS analogs. Therefore, we examined the effects of FS and six FS derivatives on recombinant ACs 1, 2 and 5, representing members of different mAC families. Correlations of the pharmacological properties of the different AC isoforms revealed pronounced differences between ACs 1, 2 and 5. Additionally, potencies and efficacies of FS derivatives changed for any given AC isoform, depending on the metal ion, Mg(2+) or Mn(2+). The most striking effects of Mg(2+) and Mn(2+) on the diterpene profile were observed for AC2 where the large inhibitory effect of BODIPY-FS in the presence of Mg(2+) was considerably reduced in the presence of Mn(2+). Sequence alignment and docking experiments confirmed an exceptional position of AC2 compared to ACs 1 and 5 with respect to the structural environment of the catalytic core and cation-dependent diterpene effects. In conclusion, mAC isoforms 1, 2 and 5 exhibit a distinct pharmacological diterpene profile, depending on the divalent cation present. mAC crystal structures and modelling/docking studies provided an explanation for the pharmacological differences between the AC isoforms. Our study constitutes an important step towards the development of isoform-specific diterpenes exhibiting stimulatory or inhibitory effects. Copyright © 2011 Elsevier Inc. All rights reserved.

Sex differences in the subjective effects of oral Δ9-THC in cannabis users.

PubMed

Fogel, Jessica S; Kelly, Thomas H; Westgate, Philip M; Lile, Joshua A

2017-01-01

Previous studies suggest that there are sex differences in endocannabinoid function and the response to exogenous cannabinoids, though data from clinical studies comparing acute cannabinoid effects in men and women under controlled laboratory conditions are limited. To further explore these potential differences, data from 30 cannabis users (N=18 M, 12 F) who completed previous Δ 9 -tetrahydrocannabinol (Δ 9 -THC) discrimination studies were combined for this retrospective analysis. In each study, subjects learned to discriminate between oral Δ 9 -THC and placebo and then received a range of Δ 9 -THC doses (0, 5, 15 and a "high" dose of either 25 or 30mg). Responses on a drug-discrimination task, subjective effects questionnaire, psychomotor performance tasks, and physiological measures were assessed. Δ 9 -THC dose-dependently increased drug-appropriate responding, ratings on "positive" Visual Analog Scale (VAS) items (e.g., good effects, like drug, take again), and items related to intoxication (e.g., high, stoned). Δ 9 -THC also dose-dependently impaired performance on psychomotor tasks and elevated heart rate. Sex differences on VAS items emerged as a function of dose. Women exhibited significantly greater subjective responses to oral drug administration than men at the 5mg Δ 9 -THC dose, whereas men were more sensitive to the subjective effects of the 15mg dose of Δ 9 -THC than women. These results demonstrate dose-dependent separation in the subjective response to oral Δ 9 -THC administration by sex, which might contribute to the differential development of problematic cannabis use. Copyright © 2015 Elsevier Inc. All rights reserved.

Wood smoke particles from different combustion phases induce similar pro-inflammatory effects in a co-culture of monocyte and pneumocyte cell lines

PubMed Central

2012-01-01

Background Exposure to particulate matter (PM) has been linked to several adverse cardiopulmonary effects, probably via biological mechanisms involving inflammation. The pro-inflammatory potential of PM depends on the particles’ physical and chemical characteristics, which again depend on the emitting source. Wood combustion is a major source of ambient air pollution in Northern countries during the winter season. The overall aim of this study was therefore to investigate cellular responses to wood smoke particles (WSPs) collected from different phases of the combustion cycle, and from combustion at different temperatures. Results WSPs from different phases of the combustion cycle induced very similar effects on pro-inflammatory mediator release, cytotoxicity and cell number, whereas WSPs from medium-temperature combustion were more cytotoxic than WSPs from high-temperature incomplete combustion. Furthermore, comparisons of effects induced by native WSPs with the corresponding organic extracts and washed particles revealed that the organic fraction was the most important determinant for the WSP-induced effects. However, the responses induced by the organic fraction could generally not be linked to the content of the measured polycyclic aromatic hydrocarbons (PAHs), suggesting that also other organic compounds were involved. Conclusion The toxicity of WSPs seems to a large extent to be determined by stove type and combustion conditions, rather than the phase of the combustion cycle. Notably, this toxicity seems to strongly depend on the organic fraction, and it is probably associated with organic components other than the commonly measured unsubstituted PAHs. PMID:23176191

Indistinguishable Synaptic Pharmacodynamics of the N-Methyl-d-Aspartate Receptor Channel Blockers Memantine and Ketamine

PubMed Central

Emnett, Christine M.; Eisenman, Lawrence N.; Taylor, Amanda M.; Izumi, Yukitoshi; Zorumski, Charles F.

2013-01-01

Memantine and ketamine, voltage- and activation-dependent channel blockers of N-methyl-d-aspartate (NMDA) receptors (NMDARs), have enjoyed a recent resurgence in clinical interest. Steady-state pharmacodynamic differences between these blockers have been reported, but it is unclear whether the compounds differentially affect dynamic physiologic signaling. In this study, we explored nonequilibrium conditions relevant to synaptic transmission in hippocampal networks in dissociated culture and hippocampal slices. Equimolar memantine and ketamine had indistinguishable effects on the following measures: steady-state NMDA currents, NMDAR excitatory postsynaptic current (EPSC) decay kinetics, progressive EPSC inhibition during repetitive stimulation, and extrasynaptic NMDAR inhibition. Therapeutic drug efficacy and tolerability of memantine have been attributed to fast kinetics and strong voltage dependence. However, pulse depolarization in drug presence revealed a surprisingly slow and similar time course of equilibration for the two compounds, although memantine produced a more prominent fast component (62% versus 48%) of re-equilibration. Simulations predicted that low gating efficacy underlies the slow voltage–dependent relief from block. This prediction was empirically supported by faster voltage-dependent blocker re-equilibration with several experimental manipulations of gating efficacy. Excitatory postsynaptic potential–like voltage commands produced drug differences only with large, prolonged depolarizations unlikely to be attained physiologically. In fact, we found no difference between drugs on measures of spontaneous network activity or acute effects on plasticity in hippocampal slices. Despite indistinguishable synaptic pharmacodynamics, ketamine provided significantly greater neuroprotection from damage induced by oxygen glucose deprivation, consistent with the idea that under extreme depolarizing conditions, the biophysical difference between drugs becomes detectable. We conclude that despite subtle differences in voltage dependence, during physiologic activity, blocker pharmacodynamics are largely indistinguishable and largely voltage independent. PMID:24101301

Quantitative characterization of spin-orbit torques in Pt/Co/Pt/Co/Ta/BTO heterostructures due to the magnetization azimuthal angle dependence

NASA Astrophysics Data System (ADS)

Engel, Christian; Goolaup, Sarjoosing; Luo, Feilong; Lew, Wen Siang

2017-08-01

Substantial understanding of spin-orbit interactions in heavy-metal (HM)/ferromagnet (FM) heterostructures is crucial in developing spin-orbit torque (SOT) spintronics devices utilizing spin Hall and Rashba effects. Though the study of SOT effective field dependence on the out-of-plane magnetization angle has been relatively extensive, the understanding of in-plane magnetization angle dependence remains unknown. Here, we analytically propose a method to compute the SOT effective fields as a function of the in-plane magnetization angle using the harmonic Hall technique in perpendicular magnetic anisotropy (PMA) structures. Two different samples with PMA, a Pt /Co /Pt /Co /Ta /BaTi O3 (BTO) test sample and a Pt/Co/Pt/Co/Ta reference sample, are studied using the derived formula. Our measurements reveal that only the dampinglike field of the test sample with a BTO capping layer exhibits an in-plane magnetization angle dependence, while no angular dependence is found in the reference sample. The presence of the BTO layer in the test sample, which gives rise to a Rashba effect at the interface, is ascribed as the source of the angular dependence of the dampinglike field.

Effect of amiodarone and dronedarone administration in rats on thyroid hormone-dependent gene expression in different cardiac components.

PubMed

Stoykov, I; van Beeren, H C; Moorman, A F M; Christoffels, V M; Wiersinga, W M; Bakker, O

2007-06-01

In view of their different actions on thyroid hormone receptor (TR) isoforms we set out to investigate whether amiodarone (AM) and dronedarone (Dron) have different and/or component-specific effects on cardiac gene expression. Rats were treated with AM or Dron and the expression of TRalpha 1, TRalpha 2, TRbeta 1 and several tri-iodothyronine (T3)-regulated genes was studied in different parts of the heart, namely the right atrium (RA), left ventricular wall (LVW) and apex. Rats were treated for 14 days with 100 mg/kg body weight AM or Dron. The expression of TRalpha 1, TRalpha 2, TRbeta 1 and T3-regulated genes was studied using real-time PCR and non-radioactive in situ hybridisation. AM and Dron affected TR expression in the RA similarly by decreasing TRalpha 1 and beta 1 expression by about 50%. In the LVW, AM and Dron decreased TRbeta 1 and, interestingly, AM increased TRalpha 1. In the apex, AM also increased TRalpha 2. The changes seen in T3-dependent gene expression are reminiscent of foetal reprogramming. Taken together, our results indicate that AM and Dron have similar effects on the expression of TR isoforms in the RA, which could partly contribute to their ability to decrease heart rate. On the other hand, the more profound effect of AM appears on TR- and T3-dependent gene expression in the left ventricle suggests foetal reprogramming.

Organ and tissue-dependent effect of resveratrol and exercise on antioxidant defenses of old mice.

PubMed

Tung, Bui Thanh; Rodriguez-Bies, Elisabet; Thanh, Hai Nguyen; Le-Thi-Thu, Huong; Navas, Plácido; Sanchez, Virginia Motilva; López-Lluch, Guillermo

2015-12-01

Oxidative stress has been considered one of the causes of aging. For this reason, treatments based on antioxidants or those capable of increasing endogenous antioxidant activity have been taken into consideration to delay aging or age-related disease progression. In this paper, we determine if resveratrol and exercise have similar effect on the antioxidant capacity of different organs in old mice. Resveratrol (6 months) and/or exercise (1.5 months) was administered to old mice. Markers of oxidative stress (lipid peroxidation and glutathione) and activities and levels of antioxidant enzymes (SOD, catalase, glutathione peroxidase, glutathione reductase and transferase and thioredoxin reductases, NADH cytochrome B5-reductase and NAD(P)H-quinone acceptor oxidoreductase) were determined by spectrophotometry and Western blotting in different organs: liver, kidney, skeletal muscle, heart and brain. Both interventions improved antioxidant activity in the major organs of the mice. This induction was accompanied by a decrease in the level of lipid peroxidation in the liver, heart and muscle of mice. Both resveratrol and exercise modulated several antioxidant activities and protein levels. However, the effect of resveratrol, exercise or their combination was organ dependent, indicating that different organs respond in different ways to the same stimulus. Our data suggest that physical activity and resveratrol may be of great importance for the prevention of age-related diseases, but that their organ-dependent effect must be taken into consideration to design a better intervention.

Psychological treatments for stimulant misuse, comparing and contrasting those for amphetamine dependence and those for cocaine dependence.

PubMed

Vocci, Frank J; Montoya, Iván D

2009-05-01

The aim is to compare and contrast psychological treatments for amphetamine and cocaine dependence. Stimulant dependence, in the form of cocaine or amphetamine/methamphetamine dependence, is prevalent worldwide, and their ratio may vary across different countries and regions of countries. The treatment of stimulant disorders has greatly advanced in recent years, and scientific evaluation of behavioral therapies, using randomized clinical trials designs and a stage-wise approach, have demonstrated the safety and efficacy of interventions. Psychological interventions such as cognitive behavioral therapy and contingency management for cocaine and methamphetamines use disorders are well tolerated and moderately effective in achieving drug abstinence. There is evidence that contingency management interventions can help to improve retention in treatment and, in turn, other treatment outcomes. Although there are important differences in the neuropsychiatric and medical consequences of cocaine and amphetamine use disorders, there is currently no evidence for a differential treatment effect of any psychosocial treatment in the management of these disorders. As there are no Food and Drug Administration-approved medications for the treatment of these disorders, psychological interventions form the basis of their treatment. More research is needed to address the specific psychosocial needs of cocaine and amphetamine-dependent individuals in order to improve their treatment outcomes.

Dependent scattering and absorption by densely packed discrete spherical particles: Effects of complex refractive index

NASA Astrophysics Data System (ADS)

Ma, L. X.; Tan, J. Y.; Zhao, J. M.; Wang, F. Q.; Wang, C. A.; Wang, Y. Y.

2017-07-01

Due to the dependent scattering and absorption effects, the radiative transfer equation (RTE) may not be suitable for dealing with radiative transfer in dense discrete random media. This paper continues previous research on multiple and dependent scattering in densely packed discrete particle systems, and puts emphasis on the effects of particle complex refractive index. The Mueller matrix elements of the scattering system with different complex refractive indexes are obtained by both electromagnetic method and radiative transfer method. The Maxwell equations are directly solved based on the superposition T-matrix method, while the RTE is solved by the Monte Carlo method combined with the hard sphere model in the Percus-Yevick approximation (HSPYA) to consider the dependent scattering effects. The results show that for densely packed discrete random media composed of medium size parameter particles (equals 6.964 in this study), the demarcation line between independent and dependent scattering has remarkable connections with the particle complex refractive index. With the particle volume fraction increase to a certain value, densely packed discrete particles with higher refractive index contrasts between the particles and host medium and higher particle absorption indexes are more likely to show stronger dependent characteristics. Due to the failure of the extended Rayleigh-Debye scattering condition, the HSPYA has weak effect on the dependent scattering correction at large phase shift parameters.

Convective Heat Transfer in Internal Gas Flows with Temperature-Dependent Properties.

DTIC Science & Technology

1982-06-30

and carbon dioxide in order to examine the effects of physica’, properties differing from those of air. Helium was chosen to reore- sent the behavior of...monatomic gases and carbon dioxide because the temper- azure dependencies of its transoort oroperties differs mar’ ed-v frorn those of air. He...conditions cor- responding to pure forced convection and to significant buoyancy forces in the thermal entry region. For carbon dioxide only temperatures

Size- and dose-dependent toxicity of cellulose nanocrystals (CNC) on human fibroblasts and colon adenocarcinoma.

PubMed

Hanif, Zahid; Ahmed, Farrukh R; Shin, Seung Won; Kim, Young-Kee; Um, Soong Ho

2014-07-01

A controlled preparation of cellulose nanocrystals of different sizes and shapes has been carried out by acid hydrolysis of microcrystalline cellulose. The size- and concentration-dependent toxicity effects of the resulting cellulose nanocrystals were evaluated against two different cell lines, NIH3T3 murine embryo fibroblasts and HCT116 colon adenocarcinoma. It could serve as a therapeutic platform for cancer treatment. Copyright © 2014 Elsevier B.V. All rights reserved.

Influence of Thickness and Interface on the Low-Temperature Enhancement of the Spin Seebeck Effect in YIG Films

DOE PAGES

Guo, Er-Jia; Cramer, Joel; Kehlberger, Andreas; ...

2016-07-27

The temperature-dependent longitudinal spin Seebeck effect (LSSE) in heavy metal (HM)/Y 3Fe 5O 12 (YIG) hybrid structures is investigated as a function of YIG film thickness, magnetic field strength, and different HM detection materials. The LSSE signal shows a large enhancement with reductions in temperature, leading to a pronounced peak at low temperatures. Here we find that the LSSE peak temperature strongly depends on the film thickness as well as on the magnetic field. Our result can be well explained in the framework of magnon-driven LSSE by taking into account the temperature-dependent effective propagation length of thermally excited magnons inmore » the bulk of the material. We further demonstrate that the LSSE peak is significantly shifted by changing the interface coupling to an adjacent detection layer, revealing a more complex behavior beyond the currently discussed bulk effect. By direct microscopic imaging of the interface, we correlate the observed temperature dependence with the interface structure between the YIG and the adjacent metal layer. Finally, our results highlight the role of interface effects on the temperature-dependent LSSE in HM/YIG system, suggesting that the temperature-dependent spin current transparency strikingly relies on the interface conditions.« less

The Two Faces of Social Interaction Reward in Animal Models of Drug Dependence.

PubMed

El Rawas, Rana; Saria, Alois

2016-03-01

Drug dependence is a serious health and social problem. Social factors can modify vulnerability to developing drug dependence, acting as risk factors or protective factors. Whereas stress and peer environment that encourage substance use may increase drug taking, strong attachments between family members and peer environment that do not experience drug use may protect against drug taking and, ultimately, drug dependence. The rewarding effects of drug abuse and social interaction can be evaluated using animal models. In this review we focus on evaluating social interaction reward in the conditioned place preference paradigm. We give an overview of how social interaction, if made available within the drug context, may facilitate, promote and interact with the drug's effects. However, social interaction, if offered alternatively outside the drug context, may have pronounced protective effects against drug abuse and relapse. We also address the importance of the weight difference parameter between the social partners in determining the positive or "agonistic" versus the hostile or "antagonistic" social interaction. We conclude that understanding social interaction reward and its subsequent effects on drug reward is sorely needed for therapeutic interventions against drug dependence.

Effect of defect imbalance on void swelling distributions produced in pure iron irradiated with 3.5 MeV self-ions

DOE PAGES

Shao, Lin; Wei, C. -C.; Gigax, J.; ...

2014-06-10

Ion irradiation has been widely used to simulate radiation damage induced by neutrons. However, there are a number of features of ion-induced damage that differ from neutron-induced damage, and these differences require investigation before behavior arising from neutron bombardment can be confidently predicted from ion data. In this study 3.5 MeV self-ion irradiation of pure iron was used to study the influence on void swelling of the depth-dependent defect imbalance between vacancies and interstitials that arises from various surface effects, forward scattering of displaced atoms, and especially the injected interstitial effect. The depth dependence of void swelling was observed notmore » to follow the behavior anticipated from the depth dependence of the damage rate. Void nucleation and growth develop first in the lower-dose, near-surface region, and then, during continued irradiation, move to progressively deeper and higher-damage depths. This indicates a strong initial suppression of void nucleation in the peak damage region that continued irradiation eventually overcomes. This phenomenon is shown by the Boltzmann transport equation method to be due to depth-dependent defect imbalances created under ion irradiation. These findings thus demonstrate that void swelling does not depend solely on the local dose level and that this sensitivity of swelling to depth must be considered in extracting and interpreting ion-induced swelling data.« less

Sex-dependent neural effect of oxytocin during subliminal processing of negative emotion faces.

PubMed

Luo, Lizhu; Becker, Benjamin; Geng, Yayuan; Zhao, Zhiying; Gao, Shan; Zhao, Weihua; Yao, Shuxia; Zheng, Xiaoxiao; Ma, Xiaole; Gao, Zhao; Hu, Jiehui; Kendrick, Keith M

2017-11-15

In line with animal models indicating sexually dimorphic effects of oxytocin (OXT) on social-emotional processing, a growing number of OXT-administration studies in humans have also reported sex-dependent effects during social information processing. To explore whether sex-dependent effects already occur during early, subliminal, processing stages the present pharmacological fMRI-study combined the intranasal-application of either OXT or placebo (n = 86-43 males) with a backward-masking emotional face paradigm. Results showed that while OXT suppressed inferior frontal gyrus, dorsal anterior cingulate and anterior insula responses to threatening face stimuli in men it increased them in women. In women increased anterior cingulate reactivity during subliminal threat processing was also positively associated with trait anxiety. On the network level, sex-dependent effects were observed on amygdala, anterior cingulate and inferior frontal gyrus functional connectivity that were mainly driven by reduced coupling in women following OXT. Our findings demonstrate that OXT produces sex-dependent effects even at the early stages of social-emotional processing, and suggest that while it attenuates neural responses to threatening social stimuli in men it increases them in women. Thus in a therapeutic context OXT may potentially produce different effects on anxiety disorders in men and women. Copyright © 2017 Elsevier Inc. All rights reserved.

Concentration rather than dose defines the local brain toxicity of agents that are effectively distributed by convection-enhanced delivery.

PubMed

Zhang, Rong; Saito, Ryuta; Mano, Yui; Kanamori, Masayuki; Sonoda, Yukihiko; Kumabe, Toshihiro; Tominaga, Teiji

2014-01-30

Convection-enhanced delivery (CED) has been developed as a potentially effective drug-delivery strategy into the central nervous system. In contrast to systemic intravenous administration, local delivery achieves high concentration and prolonged retention in the local tissue, with increased chance of local toxicity, especially with toxic agents such as chemotherapeutic agents. Therefore, the factors that affect local toxicity should be extensively studied. With the assumption that concentration-oriented evaluation of toxicity is important for local CED, we evaluated the appearance of local toxicity among different agents after delivery with CED and studied if it is dose dependent or concentration dependent. Local toxicity profile of chemotherapeutic agents delivered via CED indicates BCNU was dose-dependent, whereas that of ACNU was concentration-dependent. On the other hand, local toxicity for doxorubicin, which is not distributed effectively by CED, was dose-dependent. Local toxicity for PLD, which is extensively distributed by CED, was concentration-dependent. Traditional evaluation of drug induced toxicity was dose-oriented. This is true for systemic intravascular delivery. However, with local CED, toxicity of several drugs exacerbated in concentration-dependent manner. From our study, local toxicity of drugs that are likely to distribute effectively tended to be concentration-dependent. Concentration rather than dose may be more important for the toxicity of agents that are effectively distributed by CED. Concentration-oriented evaluation of toxicity is more important for CED. Copyright © 2013 Elsevier B.V. All rights reserved.

A time-dependent probabilistic seismic-hazard model for California

USGS Publications Warehouse

Cramer, C.H.; Petersen, M.D.; Cao, T.; Toppozada, Tousson R.; Reichle, M.

2000-01-01

For the purpose of sensitivity testing and illuminating nonconsensus components of time-dependent models, the California Department of Conservation, Division of Mines and Geology (CDMG) has assembled a time-dependent version of its statewide probabilistic seismic hazard (PSH) model for California. The model incorporates available consensus information from within the earth-science community, except for a few faults or fault segments where consensus information is not available. For these latter faults, published information has been incorporated into the model. As in the 1996 CDMG/U.S. Geological Survey (USGS) model, the time-dependent models incorporate three multisegment ruptures: a 1906, an 1857, and a southern San Andreas earthquake. Sensitivity tests are presented to show the effect on hazard and expected damage estimates of (1) intrinsic (aleatory) sigma, (2) multisegment (cascade) vs. independent segment (no cascade) ruptures, and (3) time-dependence vs. time-independence. Results indicate that (1) differences in hazard and expected damage estimates between time-dependent and independent models increase with decreasing intrinsic sigma, (2) differences in hazard and expected damage estimates between full cascading and not cascading are insensitive to intrinsic sigma, (3) differences in hazard increase with increasing return period (decreasing probability of occurrence), and (4) differences in moment-rate budgets increase with decreasing intrinsic sigma and with the degree of cascading, but are within the expected uncertainty in PSH time-dependent modeling and do not always significantly affect hazard and expected damage estimates.

Differential Effects of HRAS Mutation on LTP-Like Activity Induced by Different Protocols of Repetitive Transcranial Magnetic Stimulation.

PubMed

Dileone, Michele; Ranieri, Federico; Florio, Lucia; Capone, Fioravante; Musumeci, Gabriella; Leoni, Chiara; Mordillo-Mateos, Laura; Tartaglia, Marco; Zampino, Giuseppe; Di Lazzaro, Vincenzo

2016-01-01

Costello syndrome (CS) is a rare congenital disorder due to a G12S amino acid substitution in HRAS protoncogene. Previous studies have shown that Paired Associative Stimulation (PAS), a repetitive brain stimulation protocol inducing motor cortex plasticity by coupling peripheral nerve stimulation with brain stimulation, leads to an extremely pronounced motor cortex excitability increase in CS patients. Intermittent Theta Burst Stimulation (iTBS) represents a protocol able to induce motor cortex plasticity by trains of stimuli at 50 Hz. In healthy subjects PAS and iTBS produce similar after-effects in motor cortex excitability. Experimental models showed that HRAS-dependent signalling pathways differently affect LTP induced by different patterns of repetitive synaptic stimulation. We aimed to compare iTBS-induced after-effects on motor cortex excitability with those produced by PAS in CS patients and to observe whether HRAS mutation differentially affects two different forms of neuromodulation protocols. We evaluated in vivo after-effects induced by PAS and iTBS applied over the right motor cortex in 4 CS patients and in 21 healthy age-matched controls. Our findings confirmed HRAS-dependent extremely pronounced PAS-induced after-effects and showed for the first time that iTBS induces no change in MEP amplitude in CS patients whereas both protocols lead to an increase of about 50% in controls. CS patients are characterized by an impairment of iTBS-related LTP-like phenomena besides enhanced PAS-induced after-effects, suggesting that HRAS-dependent signalling pathways have a differential influence on PAS- and iTBS-induced plasticity in humans. Copyright © 2015 Elsevier Inc. All rights reserved.

Introduction to Chemistry and Applications in Nature of Mass Independent Isotope Effects Special Feature

PubMed Central

Thiemens, Mark H.

2013-01-01

Stable isotope ratio variations are regulated by physical and chemical laws. These rules depend on a relation with mass differences between isotopes. New classes of isotope variation effects that deviate from mass dependent laws, termed mass independent isotope effects, were discovered in 1983 and have a wide range of applications in basic chemistry and nature. In this special edition, new applications of these effects to physical chemistry, solar system origin models, terrestrial atmospheric and biogenic evolution, polar paleo climatology, snowball earth geology, and present day atmospheric sciences are presented. PMID:24167299

The difference in LET and ion species dependence for induction of initially measured and non-rejoined chromatin breaks in normal human fibroblasts.

PubMed

Tsuruoka, Chizuru; Suzuki, Masao; Hande, M Prakash; Furusawa, Yoshiya; Anzai, Kazunori; Okayasu, Ryuichi

2008-08-01

We studied the LET and ion species dependence of the induction of chromatin breaks measured immediately after irradiation as initially measured breaks and after 24 h postirradiation incubation (37 degrees C) as non-rejoined breaks in normal human fibroblasts with different heavy ions, such as carbon, neon, silicon and iron, generated by the Heavy Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Science (NIRS). Chromatin breaks were measured as an excess number of fragments of prematurely condensed chromosomes using premature chromosome condensation (PCC). The results showed that the number of excess fragments per cell per Gy for initially measured chromatin breaks was dependent on LET in the range from 13.3 to 113.1 keV/mum but was not dependent on ion species. On the other hand, the number of non-rejoined chromatin breaks detected after 24 h postirradiation incubation was clearly dependent on both LET and ion species. No significant difference was observed in the cross section for initially measured breaks, but a statistically significant difference was observed in the cross section for non-rejoined breaks among carbon, neon, silicon and iron ions. This suggests that the LET-dependent structure in the biological effects is reflected in biological consequences of repair processes.

Nicotine anxiogenic and rewarding effects are decreased in mice lacking β-endorphin

PubMed Central

Trigo, José M.; Zimmer, Andreas; Maldonado, Rafael

2009-01-01

The endogenous opioid system plays an important role in the behavioral effects of nicotine. Thus, μ-opioid receptor and the endogenous opioids derived from proenkephalin are involved in the central effects of nicotine. However, the role played by the different endogenous opioid peptides in the acute and chronic effects of nicotine remains to be fully established. Mice lacking β-endorphin were acutely injected with nicotine at different doses to evaluate locomotor, anxiogenic and antinociceptive responses. The rewarding properties of nicotine were evaluated by using the conditioned place-preference paradigm. Mice chronically treated with nicotine were acutely injected with mecamylamine to study the behavioral expression of nicotine withdrawal. Mice lacking β-endorphin exhibited a spontaneous hypoalgesia and hyperlocomotion and a reduction on the anxiogenic and rewarding effects induced by nicotine. Nicotine induced similar antinociception and hypolocomotion in both genotypes and no differences were found in the development of physical dependence. The dissociation between nicotine rewarding properties and physical dependence suggests a differential implication of β-endorphin in these addictive related responses. PMID:19376143

Depth-dependent positron annihilation in different polymers

NASA Astrophysics Data System (ADS)

Yang, J.; Zhang, P.; Cheng, G. D.; Li, D. X.; Wu, H. B.; Li, Z. X.; Cao, X. Z.; Jia, Q. J.; Yu, R. S.; Wang, B. Y.

2013-09-01

Depth-dependent positron annihilation Doppler broadening measurements were conducted for polymers with different chemical compositions. Variations of the S parameter with respect to incident positron energy were observed. For pure hydrocarbons PP, HDPE and oxygen-containing polymer PC, S parameter rises with increasing positron implantation depth. While for PI and fluoropolymers like PTFE, ETFE and PVF, S parameter decreases with higher positron energy. For chlorine-containing polymer PVDC, S parameter remains nearly constant at all incident positron energies. It is suggested that these three variation trends are resulted from a competitive effect between the depth-dependent positronium formation and the influence of highly electronegative atoms on positron annihilation characteristics.

The Effects of Size, Shape, and Surface Functional Group of Gold Nanostructures on Their Adsorption and Internalization by Cells

PubMed Central

Cho, Eun Chul; Au, Leslie; Zhang, Qiang; Xia, Younan

2010-01-01

In this study, we examined the effects of size, shape, and surface chemistry of gold nanostructures on their uptake (including both adsorption and internalization) by SK-BR-3 breast cancer cells. We used both spherical and cubic Au nanostructures (nanospheres and nanocages, respectively) of two different sizes, and their surface was modified with poly(ethylene glycol) (PEG), antibody anti-HER2, or poly(allyamine hydrochloride) (PAA). Our results showed that the size of the Au nanostructures influenced their uptake by the cells in a similar way regardless of the surface chemistry, while the shape dependency could vary depending on the surface functional group. In addition, the cells preferred to take up the Au nanostructures covered by different surface groups in the following order: PAA>> anti-HER2> PEG. The fraction of Au nanostructures attached to the cell surface was also dependent on the aforementioned parameters. PMID:20029850

Cognitive Abilities That Mediate SES's Effect on Elementary Mathematics Learning: The Uruguayan Tablet-Based Intervention

ERIC Educational Resources Information Center

Valle-Lisboa, Juan; Cabana, Álvaro; Eisinger, Robert; Mailhos, Álvaro; Luzardo, Mario; Halberda, Justin; Maiche, Alejandro

2016-01-01

In unequal societies the effectiveness of formal education depends on the socioeconomic status (SES) of students. Studies have shown that poverty affects the development of the brain in ways that might compromise future learning, thus increasing the differences between groups with different SES. Interest is growing in the development of tools that…

Parental Choice and School Quality when Peer and Scale Effects Matter

ERIC Educational Resources Information Center

O'Shaughnessy, Terry

2007-01-01

This paper presents a model of school choice with peer effects and scale economies within schools. Parents' perception of school quality depends on resources and on the characteristics of the student body. A network of local schools of uniform quality will be optimal, even though different households prefer different qualities. Whether schools of…

Are Tobacco Dependence and Withdrawal Related Amongst Heavy Smokers? Relevance to Conceptualizations of Dependence

PubMed Central

Baker, Timothy B.; Piper, Megan E.; Schlam, Tanya R.; Cook, Jessica W.; Smith, Stevens S.; Loh, Wei-Yin; Bolt, Daniel

2013-01-01

Measured tobacco dependence is typically only modestly related to tobacco withdrawal severity amongst regular smokers making a quit attempt. The weak association between dependence and withdrawal is notable because it conflicts with core theories of dependence and because both measures predict cessation outcomes, suggesting they both index a common dependence construct. This study used data from a smoking cessation comparative effectiveness trial (N = 1504) to characterize relations of tobacco dependence with craving and negative affect withdrawal symptoms using multiple dependence measures and analytic methods to detect both additive and interactive effects and to determine whether withdrawal meaningfully mediates the influence of dependence on smoking cessation. We conclude: (1) while univariate analyses suggest dependence and withdrawal measures are only modestly interrelated, more powerful analytic techniques show they are, in fact, meaningfully related and their shared variance is associated with cessation likelihood; (2) there are clear differences between craving and negative affective withdrawal symptoms, with the former more related to smoking heaviness and the latter related to trait measures of negative affect; moreover, craving more strongly mediates dependence effects on cessation; (3) both craving and negative affect withdrawal symptoms are strongly related to a pattern of regular smoking that is sensitive to the passage of time and powerfully affected by smoking cues. These findings support models that accord an important role for associative processes and withdrawal symptoms, especially craving, in drug dependence. The findings also support the use of withdrawal variables as criteria for the evaluation of dependence measures. PMID:22642839

Phloretin-induced reduction in dipole potential of sterol-containing bilayers.

PubMed

Ostroumova, Olga S; Efimova, Svetlana S; Schagina, Ludmila V

2013-12-01

The phloretin-induced reduction in the dipole potential of planar lipid bilayers containing cholesterol, ergosterol, stigmasterol, 7-dehydrocholesterol and 5α-androstan-3β-ol was investigated. It is shown that effects depend on the type and concentration of membrane sterol. It is supposed that the effectiveness of phloretin in reducing the dipole potential of the bilayers that contain cholesterol, ergosterol and 7-dehydrocholesterol correlates with the ordering and condensing effects. The role of the concentration-dependent ability of different sterols to promote lateral heterogeneity in membranes is also discussed.

Age and sex differences in ranges of motion and motion patterns.

PubMed

Hwang, Jaejin; Jung, Myung-Chul

2015-01-01

This study investigated the effects of age and sex on joint ranges of motion (ROMs) and motion patterns. Forty participants performed 18 motions using eight body segments at self-selected speeds. Older subjects showed smaller ROMs than younger subjects for 11 motions; the greatest difference in ROM was 44.9% for eversion/inversion of the foot. Older subjects also required more time than younger subjects to approach the peak angular velocity for six motions. In contrast, sex significantly affected ROMs but not motion patterns. Male subjects exhibited smaller ROMs than female subjects for four motions; the greatest sex-dependent difference in ROM was 29.7% for ulnar/radial deviation of the hand. The age and sex effects depended on the specific segments used and motions performed, possibly because of differences in anatomical structures and frequencies of use of the joints in habitual physical activities between the groups.

Effect of natural fibers on mechanical properties of green cement mortar

NASA Astrophysics Data System (ADS)

AL-Zubaidi, Aseel B.

2018-05-01

Natural fibers of banana, reed, palm and coconut were used to reinforce cement composite. Optical microscopy showed that the prepared fibers are different in size and morphology. Nearly equiaxed, ribbon-like and nearly cylindrical morphologies were observed. Each of the utilized natural fibers was incorporated in the cement matrix at 0, 0.25, 0.5, 0.75 and 1.0 wt% and cured for 28 days. The scanning electron micrographs for the 1.0 wt% -reinforced composite showed differences in porosity, grain size and shape. Each of the utilized fibers has different effect on the microstructure of the cement composite that depends on the fiber size and morphology. Water absorption, thermal conductivity, bending strength, hardness and compression strengths were measured for the reinforced cement composite. It is found that the final physical and mechanical properties of the set cement composite depend on the fiber content and fiber type through the differences in their sizes and morphologies.

Sex-dependent effects of cannabis-induced analgesia.

PubMed

Cooper, Ziva D; Haney, Margaret

2016-10-01

Preclinical studies demonstrate that cannabinoid-mediated antinociceptive effects vary according to sex; it is unknown if these findings extend to humans. This retrospective analysis compared the analgesic, subjective and physiological effects of active cannabis (3.56-5.60% THC) and inactive cannabis (0.00% THC) in male (N=21) and female (N=21) cannabis smokers under double-blind, placebo-controlled conditions. Pain response was measured using the Cold-Pressor Test (CPT). Participants immersed their hand in cold water (4°C); times to report pain (pain sensitivity) and withdraw the hand (pain tolerance) were recorded. Subjective drug ratings were also measured. Among men, active cannabis significantly decreased pain sensitivity relative to inactive cannabis (p<0.01). In women, active cannabis failed to decrease pain sensitivity relative to inactive. Active cannabis increased pain tolerance in both men women immediately after smoking (p<0.001); a trend was observed for differences between men and women (p<0.10). Active cannabis also increased subjective ratings of cannabis associated with abuse liability ('Take again,' 'Liking,' 'Good drug effect'), drug strength, and 'High' relative to inactive in both men and women (p<0.01). These results indicate that in cannabis smokers, men exhibit greater cannabis-induced analgesia relative to women. These sex-dependent differences are independent of cannabis-elicited subjective effects associated with abuse-liability, which were consistent between men and women. As such, sex-dependent differences in cannabis's analgesic effects are an important consideration that warrants further investigation when considering the potential therapeutic effects of cannabinoids for pain relief. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Effects of acids on forest trees as measured by titration in vitro, inheritance of buffer capacity in Picea abies

Treesearch

F. Scholz; S. Reck

1976-01-01

The effect of acidic precipitation on vegetation is the result of an interaction between the acid and the plant. The metabolism of plants is dependent on optimal pH-values, which are maintained by regulation. There are differences in the effectiveness of regulation under such exogenous influences as acidic precipitation. These differences can be related to the...

Raman spectroscopy detection of biomolecules in biocrusts from differing environmental conditions

NASA Astrophysics Data System (ADS)

Miralles, I.; Jorge-Villar, S. E.; van Wesemael, B.; Lázaro, R.

2017-01-01

Lichens and cyanobacteria colonize inhospitable places covering a wide climate range due to their different survival strategies, such as the synthesis of protective biomolecules. The effect of ecological factors on the synthesis of biomolecules has not been widely analysed. This study aimed to assess the effects of four factors (species, microclimate, seasonality and hydration state) and their interactions on the biomolecule frequency detected by Raman Spectroscopy. We included cyanobacterial biocrusts, and the lichens Diploschistes diacapsis, Squamarina lentigera, and Lepraria isidiata; two contrasted microclimates (typical and marginal), two contrasted seasons (hot and dry vs cool and wet) and two hydration states (dry and wet). ;Species; was the most influential factor in the identity and frequency of the main biomolecules. Microclimatic differences in the range of the local specific habitats only influenced the biomolecules in cyanobacteria. There was a quadruple interaction among the factors, the effects being different mainly depending on the species. At D. diacapsis, the production of their main biomolecules depended on microclimate, although it also depended on seasonality. Nevertheless, in L. isidiata and S. lentigera microclimatic differences did not significantly affect the production of biomolecules. In the lichen species, the microhabitats exposed to relatively larger incident radiation did not show significantly larger relative frequency of photoprotective biomolecules. No clear connection between higher production of oxalates and drier microhabitats was found, suggesting that the synthesis of oxalates is not related to water reserve strategy. The pros and cons of monitor biomolecules in biocrust by Raman spectrometry were also discussed.

Money Affects Theory of Mind Differently by Gender

PubMed Central

Ridinger, Garret; McBride, Michael

2015-01-01

Theory of Mind (ToM) ─ the ability to understand other’s thoughts, intentions, and emotions ─ is important for navigating interpersonal relationships, avoiding conflict, and empathizing. Prior research has identified many factors that affect one’s ToM ability, but little work has examined how different kinds of monetary incentives affect ToM ability. We ask: Does money affect ToM ability? If so, how does the effect depend on the structure of monetary incentives? How do the differences depend on gender? We hypothesize that money will affect ToM ability differently by gender: monetary rewards increase males’ motivation to express ToM ability while simultaneously crowding out females’ motivation. This prediction is confirmed in an experiment that varies the structure of monetary rewards for correct answers in the Reading the Mind in the Eyes Test (RMET). RMET scores decrease for females and increase for males with individual payments, and this effect is stronger with competitively-structured payments. RMET scores do not significantly change when monetary earnings go to a charity. Whether money improves or hinders ToM ability, and, hence, success in social interactions, thus depends on the interaction of gender and monetary incentive structure. PMID:26633171

Money Affects Theory of Mind Differently by Gender.

PubMed

Ridinger, Garret; McBride, Michael

2015-01-01

Theory of Mind (ToM)--the ability to understand other's thoughts, intentions, and emotions--is important for navigating interpersonal relationships, avoiding conflict, and empathizing. Prior research has identified many factors that affect one's ToM ability, but little work has examined how different kinds of monetary incentives affect ToM ability. We ask: Does money affect ToM ability? If so, how does the effect depend on the structure of monetary incentives? How do the differences depend on gender? We hypothesize that money will affect ToM ability differently by gender: monetary rewards increase males' motivation to express ToM ability while simultaneously crowding out females' motivation. This prediction is confirmed in an experiment that varies the structure of monetary rewards for correct answers in the Reading the Mind in the Eyes Test (RMET). RMET scores decrease for females and increase for males with individual payments, and this effect is stronger with competitively-structured payments. RMET scores do not significantly change when monetary earnings go to a charity. Whether money improves or hinders ToM ability, and, hence, success in social interactions, thus depends on the interaction of gender and monetary incentive structure.

Tyrosine hydroxylase is activated and phosphorylated at different sites in rat pheochromocytoma PC 12 cells treated with phorbol ester and forskolin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tachikawa, E.; Tank, A.W.; Weiner, D.H.

1986-03-01

The effects of phorbol ester (4..beta..-phorbol, 12..beta..-myristate, 13..cap alpha..-acetate; TPA), an activator of Ca/sup + +//phospholipid-dependent protein kinase (PK-C), and forskolin, which stimulates adenylate cyclase and cyclic AMP-dependent protein kinase (cAMP-PK), on the activation and phosphorylation of tyrosine hydroxylase (TH) in rat pheochromocytoma (PC 12) cells were examined. Incubation of the cells with TPA (0.01-1 ..mu..M) or forskolin (0.01-0.1 ..mu..M) produces increases in activation and phosphorylation of TH in a concentration-dependent manner. The stimulatory effects of TPA are dependent on extracellular Ca/sup + +/ and are inhibited by pretreatment of the cells with trifluoperazine (TFP). The effects of forskolin aremore » independent of Ca/sup + +/ and are not inhibited by TFP. In cells treated with forskolin, the time course of the increase in cAMP correlates with the increases in TH activity and phosphorylation. cAMP levels do not increase in cells treated with TPA. There is an increase in the phosphorylation of only one tryptic phosphopeptide derived from TH in cells treated with either forskolin or TPA. The peptide phosphorylated in TPA-treated cells exhibits different elution characteristics on HPLC from that in forskolin-treated cells. The authors conclude that TH in PC 12 cells is phosphorylated on different sites by cAMP-PK and PK-C. Phosphorylation of either of these sites is associated with enzyme activation.« less

Angular dependence of EWS time delay for photoionization of @Xe

NASA Astrophysics Data System (ADS)

Mandal, Ankur; Deshmukh, Pranawa; Kheifets, Anatoli; Dolmatov, Valeriy; Manson, Steven

2017-04-01

Interference between photoionization channels leads to angular dependence in photoionization time delay. Angular dependence is found to be a common effect for two-photon absorption experiments very recently. The effect of confinement on the time delay where each partial wave contributions to the ionization are studied. In this work we report angular dependence and confinement effects on Eisenbud-Wigner-Smith (EWS) time delay in atomic photoionization. Using and we computed the EWS time delay for free and confined Xe atom for photoionization from inner 4d3/2 and 4d5/2 and outer 5p1/2 and 5p3/2 subshells at various angles. The calculated EWS time delay is few tens to few hundreds of attoseconds (10-18 second). The photoionization time delay for @Xe follows that in the free Xe atom on which the confinement oscillations are built. The present work reveals the effect of confinement on the photoionization time delay at different angles between photoelectron ejection and the photon polarization.

Analysis of opioid efficacy, tolerance, addiction and dependence from cell culture to human

PubMed Central

Morgan, Michael M; Christie, MacDonald J

2011-01-01

Opioid agonists are the most effective treatment for pain, but their use is limited by side effects, tolerance and fears of addiction and dependence. A major goal of opioid research is to develop agonists that have high analgesic efficacy and a low profile for side effects, tolerance, addiction and dependence. Unfortunately, there is a serious lack of experimental data comparing the degree to which different opioids produce these effects in humans. In contrast, a wide range of experimental techniques from heterologous expression systems to behaviour assessment in whole animals have been developed to study these problems. The objective of this review is to describe and evaluate these techniques as they are used to study opioid efficacy, tolerance, addiction and dependence. LINKED ARTICLES This article is part of a themed issue on Translational Neuropharmacology. To view the other articles in this issue visit http://dx.doi.org/10.1111/bph.2011.164.issue-4 PMID:21434879

Vibration paradox in orthodontics: Anabolic and catabolic effects

PubMed Central

Alikhani, Mani; Alansari, Sarah; Hamidaddin, Mohammad A.; Sangsuwon, Chinapa; Alyami, Bandar; Thirumoorthy, Soumya N.; Oliveira, Serafim M.; Nervina, Jeanne M.

2018-01-01

Vibration in the form of High Frequency Acceleration (HFA) is anabolic on the craniofacial skeleton in the absence of inflammation. Orthodontic forces trigger an inflammation-dependent catabolic cascade that is crucial for tooth movement. It is unknown what effect HFA has on alveolar bone if applied during orthodontic treatment. The objectives of this study are to examine the effect of HFA on the rate of tooth movement and alveolar bone, and determine the mechanism by which HFA affects tooth movement. Adult Sprague Dawley rats were divided to control, orthodontic force alone (OTM), and different experimental groups that received the same orthodontic forces and different HFA regimens. Orthodontic tooth movement was assessed when HFA parameters, frequency, acceleration, duration of exposure, and direct or indirect application were varied. We found that HFA treatment significantly enhanced the inflammation-dependent catabolic cascade during orthodontic tooth movement. HFA treatment increased inflammatory mediators and osteoclastogenesis, and decreased alveolar bone density during orthodontic tooth movement. Each of the HFA variables produced significant changes in the rate of tooth movement and the effect was PDL-dependent. This is the first report that HFA enhances inflammation-dependent catabolic cascades in bone. The clinical implications of our study are highly significant, as HFA can be utilized to enhance the rate of orthodontic tooth movement during the catabolic phase of treatment and subsequently be utilized to enhance retention during the anabolic remodeling phase after orthodontic forces are removed. PMID:29734391

The Frequency Spectral Properties of Electrode-Skin Contact Impedance on Human Head and Its Frequency-Dependent Effects on Frequency-Difference EIT in Stroke Detection from 10Hz to 1MHz.

PubMed

Yang, Lin; Dai, Meng; Xu, Canhua; Zhang, Ge; Li, Weichen; Fu, Feng; Shi, Xuetao; Dong, Xiuzhen

2017-01-01

Frequency-difference electrical impedance tomography (fdEIT) reconstructs frequency-dependent changes of a complex impedance distribution. It has a potential application in acute stroke detection because there are significant differences in impedance spectra between stroke lesions and normal brain tissues. However, fdEIT suffers from the influences of electrode-skin contact impedance since contact impedance varies greatly with frequency. When using fdEIT to detect stroke, it is critical to know the degree of measurement errors or image artifacts caused by contact impedance. To our knowledge, no study has systematically investigated the frequency spectral properties of electrode-skin contact impedance on human head and its frequency-dependent effects on fdEIT used in stroke detection within a wide frequency band (10 Hz-1 MHz). In this study, we first measured and analyzed the frequency spectral properties of electrode-skin contact impedance on 47 human subjects' heads within 10 Hz-1 MHz. Then, we quantified the frequency-dependent effects of contact impedance on fdEIT in stroke detection in terms of the current distribution beneath the electrodes and the contact impedance imbalance between two measuring electrodes. The results showed that the contact impedance at high frequencies (>100 kHz) significantly changed the current distribution beneath the electrode, leading to nonnegligible errors in boundary voltages and artifacts in reconstructed images. The contact impedance imbalance at low frequencies (<1 kHz) also caused significant measurement errors. We conclude that the contact impedance has critical frequency-dependent influences on fdEIT and further studies on reducing such influences are necessary to improve the application of fdEIT in stroke detection.

The Frequency Spectral Properties of Electrode-Skin Contact Impedance on Human Head and Its Frequency-Dependent Effects on Frequency-Difference EIT in Stroke Detection from 10Hz to 1MHz

PubMed Central

Zhang, Ge; Li, Weichen; Fu, Feng; Shi, Xuetao; Dong, Xiuzhen

2017-01-01

Frequency-difference electrical impedance tomography (fdEIT) reconstructs frequency-dependent changes of a complex impedance distribution. It has a potential application in acute stroke detection because there are significant differences in impedance spectra between stroke lesions and normal brain tissues. However, fdEIT suffers from the influences of electrode-skin contact impedance since contact impedance varies greatly with frequency. When using fdEIT to detect stroke, it is critical to know the degree of measurement errors or image artifacts caused by contact impedance. To our knowledge, no study has systematically investigated the frequency spectral properties of electrode-skin contact impedance on human head and its frequency-dependent effects on fdEIT used in stroke detection within a wide frequency band (10 Hz-1 MHz). In this study, we first measured and analyzed the frequency spectral properties of electrode-skin contact impedance on 47 human subjects’ heads within 10 Hz-1 MHz. Then, we quantified the frequency-dependent effects of contact impedance on fdEIT in stroke detection in terms of the current distribution beneath the electrodes and the contact impedance imbalance between two measuring electrodes. The results showed that the contact impedance at high frequencies (>100 kHz) significantly changed the current distribution beneath the electrode, leading to nonnegligible errors in boundary voltages and artifacts in reconstructed images. The contact impedance imbalance at low frequencies (<1 kHz) also caused significant measurement errors. We conclude that the contact impedance has critical frequency-dependent influences on fdEIT and further studies on reducing such influences are necessary to improve the application of fdEIT in stroke detection. PMID:28107524

[Treatment side effects and compliance in patients with depression].

PubMed

Petrova, N N; Kucher, E O

2012-01-01

The impact of treatment side-effects on the compliance was studied in 85 depressive patients with different mental disorders - recurrent depressive disorder, postschizophrenic depression and organic affective disorder. The comparison of objective and subjective evaluations of compliance and a comparative analysis of the level of compliance, with its dependence on the treatment specifics, in different diseases were done. A significant role of efficacy and treatment side-effects was identified. The levels of "mental" and "autonomous" side-effects were highest in the treatment of depression: patients with postschizophrenic depression had the highest risk in respect of maintenance treatment; patients with recurrent depressive disorder and organic (affective) disorder were more tolerant to the treatment side-effects and their treatment, including the maintenance therapy, was rather effective. The compliance of all patients with depression was negatively correlated with the severity of side-effects of pharmacotherapy. The greatest side-effects and the lowest level of compliance were observed in the complex treatment with antidepressants and atypical neuroleptics. The effect of side-effects on the compliance was dependent on their severity and subjective tolerability and, to a lesser extent, on the amount of drugs.

Correlation of the neutron star crust-core properties with the slope of the symmetry energy and the lead skin thickness

NASA Astrophysics Data System (ADS)

Pais, H.; Sulaksono, A.; Agrawal, B. K.; Providência, C.

2016-04-01

The correlations of the crust-core transition density and pressure in neutron stars with the slope of the symmetry energy and the neutron skin thickness are investigated, using different families of relativistic mean-field parametrizations with constant couplings and nonlinear terms mixing the σ - , ω - , and ρ -meson fields. It is shown that the modification of the density dependence of the symmetry energy, involving the σ or the ω meson, gives rise to different behaviors: the effect of the ω meson may also be reproduced within nonrelativistic phenomenological models, while the effect of the σ meson is essentially relativistic. Depending on the parametrization with σ -ρ or ω -ρ mixing terms, different values of the slope of the symmetry energy at saturation must be considered in order to obtain a neutron matter equation of state compatible with results from chiral effective field theory. This difference leads to different pressures at the crust-core transition density. A linear correlation between the transition density and the symmetry energy slope or the neutron skin thickness of the 208Pb nucleus is obtained, only when the ω meson is used to describe the density dependence of the symmetry energy. A comparison is made between the crust-core transition properties of neutron stars obtained by three different methods, the relativistic random phase approximation (RRPA), the Vlasov equation, and thermodynamical method. It is shown that the RRPA and the Vlasov methods predict similar transition densities for p n e β -equilibrium stellar matter.

Modeling and performance metrics of MIMO-SDM systems with different amplification schemes in the presence of mode-dependent loss.

PubMed

Antonelli, Cristian; Mecozzi, Antonio; Shtaif, Mark; Winzer, Peter J

2015-02-09

Mode-dependent loss (MDL) is a major factor limiting the achievable information rate in multiple-input multiple-output space-division multiplexed systems. In this paper we show that its impact on system performance, which we quantify in terms of the capacity reduction relative to a reference MDL-free system, may depend strongly on the operation of the inline optical amplifiers. This dependency is particularly strong in low mode-count systems. In addition, we discuss ways in which the signal-to-noise ratio of the MDL-free reference system can be defined and quantify the differences in the predicted capacity loss. Finally, we stress the importance of correctly accounting for the effect of MDL on the accumulation of amplification noise.

Regulation of protein degradation in muscle by calcium

NASA Technical Reports Server (NTRS)

Zeman, Richard J.; Kameyama, Tsuneo; Matsumoto, Kazue; Bernstein, Paul; Etlinger, Joseph D.

1985-01-01

Calcium-dependent regulation of intracellular protein degradation was studied in isolated rat skeletal muscles incubated in vitro in the presence of a large variety of agents known to affect calcium movement and distribution. The effect of different classes of protease inhibitors was tested to determine the responsible proteolytic systems involved in calcium-dependent degradation. The results suggest that nonlysosomal leupetin- and E-64-c-sensitive proteases are resposible for calcium-dependent proteolysis in muscle.

Decreasing Irradiated Rat Lung Volume Changes Dose-Limiting Toxicity From Early to Late Effects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Veen, Sonja J. van der; Faber, Hette; Ghobadi, Ghazaleh

2016-01-01

Purpose: Technological developments in radiation therapy result in smaller irradiated volumes of normal tissue. Because the risk of radiation therapy-induced toxicity generally depends on irradiated volume, changing volume could change the dose-limiting toxicity of a treatment. Recently, in our rat model, we found that early radiation-induced lung dysfunction (RILD) was closely related to irradiated volume dependent vascular remodeling besides inflammation. The exact relationship between early and late RILD is still unknown. Therefore, in this preclinical study we investigated the dose-volume relationship of late RILD, assessed its dependence on early and late pathologies and studied if decreasing irradiated volume changed themore » dose-limiting toxicity. Methods and Materials: A volume of 25%, 32%, 50%, 63%, 88%, or 100% of the rat lung was irradiated using protons. Until 26 weeks after irradiation, respiratory rates were measured. Macrovascular remodeling, pulmonary inflammation, and fibrosis were assessed at 26 weeks after irradiation. For all endpoints dose-volume response curves were made. These results were compared to our previously published early lung effects. Results: Early vascular remodeling and inflammation correlated significantly with early RILD. Late RILD correlated with inflammation and fibrosis, but not with vascular remodeling. In contrast to the early effects, late vascular remodeling, inflammation and fibrosis showed a primarily dose but not volume dependence. Comparison of respiratory rate increases early and late after irradiation for the different dose-distributions indicated that with decreasing irradiated volumes, the dose-limiting toxicity changed from early to late RILD. Conclusions: In our rat model, different pathologies underlie early and late RILD with different dose-volume dependencies. Consequently, the dose-limiting toxicity changed from early to late dysfunction when the irradiated volume was reduced. In patients, early and late RILD are also due to different pathologies. As such, new radiation techniques reducing irradiated volume might change the dose-limiting toxicity of the radiation therapy treatment.« less

Relative role of different radii in the dynamics of 8B+58Ni reaction

NASA Astrophysics Data System (ADS)

Kaur, Amandeep; Sandhu, Kirandeep; Sharma, Manoj K.

2018-05-01

In the present work, we intend to analyze the significance of three different radius terms in the framework of dynamical cluster-decay model (DCM) based calculations. In the majority of DCM based calculations the impact of mass- dependent radius R(A) is extensively analyzed. The other two factors on which the radius term may depend are, the neutron- proton asymmetry and the charge of the decaying fragments. Hence, the asymmetry dependent radius term R(I) and charge dependent radius term R(Z) are incorporated in DCM based calculations to investigate their effect on the reaction dynamics involved. Here, we present an extension of an earlier work based on the decay of 66As* compound nucleus by including R(I) and R(Z) radii in addition to the R(A) term. The effect of replacement of R(A) with R(I) and R(Z) is analyzed via fragmentation structure, tunneling probabilities (P) and other barrier characteristics like barrier height (VB), barrier position (RB), barrier turning point Ra etc. The role of temperature, deformations and angular momentum is duly incorporated in the present calculations.

Executive control deficits in substance-dependent individuals: a comparison of alcohol, cocaine, and methamphetamine and of men and women.

PubMed

van der Plas, Ellen A A; Crone, Eveline A; van den Wildenberg, Wery P M; Tranel, Daniel; Bechara, Antoine

2009-08-01

Substance dependence is associated with executive function deficits, but the nature of these executive defects and the effect that different drugs and sex have on these defects have not been fully clarified. Therefore, we compared the performance of alcohol- (n = 33; 18 women), cocaine- (n = 27; 14 women), and methamphetamine-dependent individuals (n = 38; 25 women) with sex-matched healthy comparisons (n = 36; 17 women) on complex decision making as measured with the Iowa Gambling Task, working memory, cognitive flexibility, and response inhibition. Cocaine- and methamphetamine-dependent individuals were impaired on complex decision making, working memory, and cognitive flexibility, but not on response inhibition. The deficits in working memory and cognitive flexibility were milder than the decision-making deficits and did not change as a function of memory load or task switching. Interestingly, decision making was significantly more impaired in women addicted to cocaine or methamphetamine than in men addicted to these drugs. Together, these findings suggest that drug of choice and sex have different effects on executive functioning, which, if replicated, may help tailor intervention.

Evolution of the characteristics of Parametric X-ray Radiation from textured polycrystals under different observation angles

NASA Astrophysics Data System (ADS)

Alekseev, V. I.; Eliseyev, A. N.; Irribarra, E.; Kishin, I. A.; Klyuev, A. S.; Kubankin, A. S.; Nazhmudinov, R. M.; Zhukova, P. N.

2018-02-01

The Parametric X-Ray radiation (PXR) spectra and yield dependencies on the orientation angle are measured during the interaction of 7 MeV electrons with a tungsten textured polycrystalline foil for different observation angles. The effects of PXR spectral density increase and PXR yield orientation dependence broadening in the backward direction is shown experimentally for the first time. The experimental results are compared with PXR kinematical theories for both mosaic crystals and polycrystals.

Direct effects dominate responses to climate perturbations in grassland plant communities

USDA-ARS?s Scientific Manuscript database

Theory predicts that strong indirect effects of environmental change will impact communities when niche differences between competitors are small and variation in the direct effects experienced by competitors is large, but empirical tests are lacking. Here we estimate negative frequency dependence, ...

Visual cues that are effective for contextual saccade adaptation

PubMed Central

Azadi, Reza

2014-01-01

The accuracy of saccades, as maintained by saccade adaptation, has been shown to be context dependent: able to have different amplitude movements to the same retinal displacement dependent on motor contexts such as orbital starting location. There is conflicting evidence as to whether purely visual cues also effect contextual saccade adaptation and, if so, what function this might serve. We tested what visual cues might evoke contextual adaptation. Over 5 experiments, 78 naive subjects made saccades to circularly moving targets, which stepped outward or inward during the saccade depending on target movement direction, speed, or color and shape. To test if the movement or context postsaccade were critical, we stopped the postsaccade target motion (experiment 4) or neutralized the contexts by equating postsaccade target speed to an intermediate value (experiment 5). We found contextual adaptation in all conditions except those defined by color and shape. We conclude that some, but not all, visual cues before the saccade are sufficient for contextual adaptation. We conjecture that this visual contextuality functions to allow for different motor states for different coordinated movement patterns, such as coordinated saccade and pursuit motor planning. PMID:24647429

Compensation of Verdet Constant Temperature Dependence by Crystal Core Temperature Measurement

PubMed Central

Petricevic, Slobodan J.; Mihailovic, Pedja M.

2016-01-01

Compensation of the temperature dependence of the Verdet constant in a polarimetric extrinsic Faraday sensor is of major importance for applying the magneto-optical effect to AC current measurements and magnetic field sensing. This paper presents a method for compensating the temperature effect on the Faraday rotation in a Bi12GeO20 crystal by sensing its optical activity effect on the polarization of a light beam. The method measures the temperature of the same volume of crystal that effects the beam polarization in a magnetic field or current sensing process. This eliminates the effect of temperature difference found in other indirect temperature compensation methods, thus allowing more accurate temperature compensation for the temperature dependence of the Verdet constant. The method does not require additional changes to an existing Δ/Σ configuration and is thus applicable for improving the performance of existing sensing devices. PMID:27706043

Meaning of the field dependence of the renormalization scale in Higgs inflation

NASA Astrophysics Data System (ADS)

Hamada, Yuta; Kawai, Hikaru; Nakanishi, Yukari; Oda, Kin-ya

2017-05-01

We consider the prescription dependence of the Higgs effective potential under the presence of general nonminimal couplings. We evaluate the fermion loop correction to the effective action in a simplified Higgs-Yukawa model whose path integral measure takes simple form either in the Jordan or Einstein frame. The resultant effective action becomes identical in both cases when we properly take into account the quartically divergent term coming from the change of measure. Working in the counterterm formalism, we clarify that the difference between the prescriptions I and II comes from the counter term to cancel the logarithmic divergence. This difference can be absorbed into the choice of tree-level potential from the infinitely many possibilities, including all the higher-dimensional terms. We also present another mechanism to obtain a flat potential by freezing the running of the effective quartic coupling for large field values, using the nonminimal coupling in the gauge kinetic function.

Carrier mobility in organic field-effect transistors

NASA Astrophysics Data System (ADS)

Xu, Yong; Benwadih, Mohamed; Gwoziecki, Romain; Coppard, Romain; Minari, Takeo; Liu, Chuan; Tsukagoshi, Kazuhito; Chroboczek, Jan; Balestra, Francis; Ghibaudo, Gerard

2011-11-01

A study of carrier transport in top-gate and bottom-contact TIPS-pentacene organic field-effect transistors (OFETs) based on mobility is presented. Among three mobilities extracted by different methods, the low-field mobility obtained by the Y function exhibits the best reliability and ease for use, whereas the widely applied field-effect mobility is not reliable, particularly in short-channel transistors and at low temperatures. A detailed study of contact transport reveals its strong impact on short-channel transistors, suggesting that a more intrinsic transport analysis is better implemented in relatively longer-channel devices. The observed temperature dependences of mobility are well explained by a transport model with Gaussian-like diffusivity band tails, different from diffusion in localized states band tails. This model explicitly interprets the non-zero constant mobility at low temperatures and clearly demonstrates the effects of disorder and hopping transport on temperature and carrier density dependences of mobility in organic transistors.

Generalized Doppler and aberration kernel for frequency-dependent cosmological observables

NASA Astrophysics Data System (ADS)

Yasini, Siavash; Pierpaoli, Elena

2017-11-01

We introduce a frequency-dependent Doppler and aberration transformation kernel for the harmonic multipoles of a general cosmological observable with spin weight s , Doppler weight d and arbitrary frequency spectrum. In the context of cosmic microwave background (CMB) studies, the frequency-dependent formalism allows to correct for the motion-induced aberration and Doppler effects on individual frequency maps with different masks. It also permits to deboost background radiations with non-blackbody frequency spectra, like extragalactic foregrounds and CMB spectra with primordial spectral distortions. The formalism can also be used to correct individual E and B polarization modes and account for motion-induced E/B mixing of polarized observables with d ≠1 at different frequencies. We apply the generalized aberration kernel on polarized and unpolarized specific intensity at 100 and 217 GHz and show that the motion-induced effects typically increase with the frequency of observation. In all-sky CMB experiments, the frequency-dependence of the motion-induced effects for a blackbody spectrum are overall negligible. However in a cut-sky analysis, ignoring the frequency dependence can lead to percent level error in the polarized and unpolarized power spectra over all angular scales. In the specific cut-sky used in our analysis (b >4 5 ° ,fsky≃14 % ), and for the dipole-inferred velocity β =0.00123 typically attributed to our peculiar motion, the Doppler and aberration effects can change polarized and unpolarized power spectra of specific intensity in the CMB rest frame by 1 - 2 % , but we find the polarization cross-leakage between E and B modes to be negligible.

Time-dependent efficiency measurements of polymer solar cells with dye additives: unexpected initial increase of efficiency

NASA Astrophysics Data System (ADS)

Bandaccari, Kyle J.; Chesmore, Grace E.; Bugaj, Mitchel; Valverde, Parisa Tajalli-Tehrani; Barber, Richard P.; McNelis, Brian J.

2018-04-01

We report the effects of the addition of two azo-dye additives on the time-dependent efficiency of polymer solar cells. Although the maximum efficiencies of devices containing different amounts of dye do not vary greatly over the selected concentration range, the time dependence results reveal a surprising initial increase in efficiency in some samples. We observe this effect to be correlated with a leakage current, although a specific mechanism is not yet identified. We also present the measured lifetimes of these solar cells, and find that variations in dye concentrations produce a small effect at most. Characterization of the bulk heterojunction layer (active layer) morphology using atomic-force microscope (AFM) imaging reveals reordering patterns which suggest that the primary effects of the dyes arise via structural, not absorptive, characteristics.

A new LDMI decomposition approach to explain emission development in the EU: individual and set contribution.

PubMed

Madaleno, Mara; Moutinho, Victor

2017-04-01

This study breaks down carbon emissions into six effects within the current 28 European Union (EU) countries group, thereafter, they are divided into two different groups (the first 15 countries (EU-15) and the last 13 entering the EU (EU13)). Country-specific highlights are also examined. It analyses the evolution of the effects using a data span that runs from 1990 to 2014, to determine which of them had more impact on the intensity of emissions, while also breaking down the complete period into two distinct periods (before the Kyoto protocol (1990-2004) and after Kyoto (2005-2014)). In order to add more knowledge to the current literature, both the additive and multiplicative decomposition techniques were used to examine carbon dioxide (CO 2 ) emissions and the selected six components: carbon intensity, fossil fuel consumption, energy intensity, oil imports intensity, oil dependence, and population effect. Results point to different adapting velocities for Kyoto targets and necessary compromises. The different velocities were translated into different positive and negative impacts in the change of behavior of CO 2 emissions throughout Europe. A stress in the fluctuations in CO 2 variations before and after Kyoto and between the two different groups of EU countries could be noticed. Moreover, energy intensity and per capita dependence of oil products were identified as the major responsible components for the total and negative changes of emissions in recent years. A decrease in total changes of emissions is observed due to the fossil fuel energy consumption effect and total petroleum products effects. It is possible to infer from here that increased renewable capacity is contributing in a positive way to eco-efficiency, and should therefore be accounted for in national policymakers' decisions in the strongest way possible. Results also seem to indicate that per capita dependence of oil products has decreased, despite oil imports intensity constancy and increased renewable capacity, however, with clear heterogeneous effects, worthy of consideration when defining policies.

Solvent effects on the fluorescence and effective three-photon absorption of a Zn(II)-[meso-tetrakis(4-octyloxyphenyl)porphyrin

NASA Astrophysics Data System (ADS)

Wan, Yong; Xue, Yuxiong; Sheng, Ning; Rui, Guanghao; Lv, Changgui; He, Jun; Gu, Bing; Cui, Yiping

2018-06-01

The fluorescence and effective three-photon absorption (3PA) properties of Zn(II)-[meso-tetrakis(4-octyloxyphenyl)porphyrin] (labeled Zn(II)-porphyrin) dissolved in three different polar solvents were systematically investigated. The electrochemical and photophysical properties of Zn(II)-porphyrin were investigated by 1H NMR spectra, IR spectra, mass spectroscopy, and electronic absorption spectra. The fluorescence emission of Zn(II)-porphyrin in three different solvents excited at the wavelengths of 420 nm (Soret band) and 550 nm (Q-band) were analyzed. By performing Z-scan experiments with femtosecond laser pulses at a wavelength of 800 nm, the effective 3PA process of Zn(II)-porphyrin in three different solvents was observed and the underlying mechanism was discussed in detail. It is found that the fluorescence spectra slightly depend on the polarity of the solvent. Interestingly, the effective 3PA properties of Zn(II)-porphyrin strongly depend on the solvent polarity. The lower the solvent polarity is, the larger effective 3PA cross-section is. Low polar solvents are beneficial to applications of Zn(II)-porphyrin in optical limiting, photodynamic therapy, etc.

[Differences of bi-directional regulative effects between acu-moxibustion and Chinese materia medica interventions].

PubMed

Cao, Xin; Yu, Zhi; Xu, Bin

2012-10-01

Bi-directional regulation is referred to a balancing effect of both acu-moxibustion and Chinese materia medica interventions when the human body is experiencing a hyperactivity or hypoactivity due to abnormal intrinsic or external factors. In the present paper, the authors analyze their identical and different characteristics from: 1) definition; 2) characters of regulative effects of acu-moxibustion therapy: A) differentiation of meridian and zangfu-organs being the basis of treatment, B) four factors (acupoint-location, body's functional state, acupoint-formula and needle-manipulation techniques) dependant, C) entirety regulation, and D) centrotaxis modulation; 3) characters of Chinese materia medica intervention: including a) correspondence between the drug property and the syndrome being the basis of the regulative effect, b) multi-factors [components (antagonist and agonist), combination, dosages and processing quality of Chinese materia medica, and functional state of the human body] dependant, c) entirety regulation, and d) both centrotaxis and deviation adjustment. In one word, the bi-directional regulation effect is one of the basic characteristics of both acu-moxibustion and Chinese materia medica in clinical practice, but their basis and modes for inducing effects are different.

[Site of prelingual cochlear stimulation and its effect on electrically evoked compound action potentials and refractory using the Nucleus 24 standard].

PubMed

Ma, R Y; Li, W; Jiang, X J

2016-12-01

Objective: To investigate the correlation between the site of prelingual cochlear stimulation and its effect on electrically evoked compound action potentials. Method: Recordings of auditory nerve responses were conducted in 32 prelingual subjects to demonstrate the feasibility of ECAP recordings using the nerve response telemetry(NRT) feature of the Nucleus CI24R(CA) system software. These recordings were then analyzed based on the site of cochlear stimulation defined as basal, middle and apical to determine if the amplitude, threshold and slope of the amplitude growth function and the refractory time differs depending on the region of stimulation. Result: Findings of our prelingual children showed significant differences in the ECAP recordings depending on the stimulation site. Comparing the apical with the basal region, on average higher amplitudes, lower thresholds and steeper slopes of the amplitude growth function hadbeen observed. The refractory time showed an overall dependence on cochlear region; however post-hoc tests showed no significant effect between individual regions. Conclusion: Obtaining ECAP recordings is also possible in the most apical region of the cochlea. However, differences can be observed depending on the region of the cochlea stimulated. Specifically, significant higher ECAP amplitude, lower thresholds and steeper amplitude growth function slopes have been observed in the apical region. These differences between prelingual children and adults could be explained by the location of the stimulating electrode with respect to the neural tissue in the cochlea, a higher density, or an increased neural survival rate of neural tissue in the apex. Copyright© by the Editorial Department of Journal of Clinical Otorhinolaryngology Head and Neck Surgery.

A new parameterization of the UV irradiance altitude dependence for clear-sky conditions and its application in the on-line UV tool over Northern Eurasia

NASA Astrophysics Data System (ADS)

Chubarova, Nataly; Zhdanova, Yekaterina; Nezval, Yelena

2016-09-01

A new method for calculating the altitude UV dependence is proposed for different types of biologically active UV radiation (erythemally weighted, vitamin-D-weighted and cataract-weighted types). We show that for the specified groups of parameters the altitude UV amplification (AUV) can be presented as a composite of independent contributions of UV amplification from different factors within a wide range of their changes with mean uncertainty of 1 % and standard deviation of 3 % compared with the exact model simulations with the same input parameters. The parameterization takes into account for the altitude dependence of molecular number density, ozone content, aerosol and spatial surface albedo. We also provide generalized altitude dependencies of the parameters for evaluating the AUV. The resulting comparison of the altitude UV effects using the proposed method shows a good agreement with the accurate 8-stream DISORT model simulations with correlation coefficient r > 0.996. A satisfactory agreement was also obtained with the experimental UV data in mountain regions. Using this parameterization we analyzed the role of different geophysical parameters in UV variations with altitude. The decrease in molecular number density, especially at high altitudes, and the increase in surface albedo play the most significant role in the UV growth. Typical aerosol and ozone altitude UV effects do not exceed 10-20 %. Using the proposed parameterization implemented in the on-line UV tool (http://momsu.ru/uv/) for Northern Eurasia over the PEEX domain we analyzed the altitude UV increase and its possible effects on human health considering different skin types and various open body fraction for January and April conditions in the Alpine region.

Hybrid Pareto artificial bee colony algorithm for multi-objective single machine group scheduling problem with sequence-dependent setup times and learning effects.

PubMed

Yue, Lei; Guan, Zailin; Saif, Ullah; Zhang, Fei; Wang, Hao

2016-01-01

Group scheduling is significant for efficient and cost effective production system. However, there exist setup times between the groups, which require to decrease it by sequencing groups in an efficient way. Current research is focused on a sequence dependent group scheduling problem with an aim to minimize the makespan in addition to minimize the total weighted tardiness simultaneously. In most of the production scheduling problems, the processing time of jobs is assumed as fixed. However, the actual processing time of jobs may be reduced due to "learning effect". The integration of sequence dependent group scheduling problem with learning effects has been rarely considered in literature. Therefore, current research considers a single machine group scheduling problem with sequence dependent setup times and learning effects simultaneously. A novel hybrid Pareto artificial bee colony algorithm (HPABC) with some steps of genetic algorithm is proposed for current problem to get Pareto solutions. Furthermore, five different sizes of test problems (small, small medium, medium, large medium, large) are tested using proposed HPABC. Taguchi method is used to tune the effective parameters of the proposed HPABC for each problem category. The performance of HPABC is compared with three famous multi objective optimization algorithms, improved strength Pareto evolutionary algorithm (SPEA2), non-dominated sorting genetic algorithm II (NSGAII) and particle swarm optimization algorithm (PSO). Results indicate that HPABC outperforms SPEA2, NSGAII and PSO and gives better Pareto optimal solutions in terms of diversity and quality for almost all the instances of the different sizes of problems.

Dependency and Self-Criticism in Treatments for Depression

PubMed Central

Chui, Harold; Zilcha-Mano, Sigal; Dinger, Ulrike; Barrett, Marna S.; Barber, Jacques P.

2016-01-01

Dependency and self-criticism are vulnerability factors for depression. How these personality factors change with treatment for depression, and how they relate to symptom change across different types of treatment require further research. In addition, cultural differences that interact with the dependency/self-criticism-depression relation remain under-investigated. One hundred and forty-nine adults with major depression were randomly assigned to receive active medication (MED; n = 50), supportive-expressive therapy (SET; n = 49), or placebo pill (PBO; n = 50). Participants completed the Depressive Experiences Questionnaire (DEQ; Blatt, D'Afflitti, & Quinlan, 1976) before and after treatment, and were administered the Hamilton Rating Scale for Depression (Hamilton, 1967) throughout the course of treatment. Self-criticism as measured on the DEQ decreased with treatment similarly across conditions. DEQ Dependency decreased in MED but remained unchanged in SET and PBO. Higher initial dependency, but not higher initial self-criticism, predicted poor treatment response across conditions. Greater reduction in self-criticism was associated with greater reduction in depressive symptoms, but the effect was weaker for racial minorities (vs. White). Increase in connectedness, an adaptive form of dependency, was associated with symptom improvement in SET but not MED. Hence, different pathways of change seem to be implicated in the treatment of depression depending on culture and type of intervention. Implications for future research are discussed. PMID:26866638

The Arg389Gly beta1-adrenoceptor polymorphism does not affect cardiac effects of exercise after parasympathetic inhibition by atropine.

PubMed

Leineweber, Kirsten; Bruck, Heike; Temme, Thomas; Heusch, Gerd; Philipp, Thomas; Brodde, Otto-Erich

2006-01-01

In vitro, Arg389Gly beta1-adrenoceptor (AR) polymorphism exhibits decreased beta-AR signalling. In vivo, beta1-AR-mediated cardiac effects of exercise showed no genotype-dependent differences in Arg389 vs. Gly389 beta1-AR subjects. We studied in 16 male subjects homozygous Arg389 or Gly389 beta1-AR, whether blockade of parasympathetic activity might unmask genotype-dependence of exercise effects. Subjects were infused with atropine (10 microg/kg i.v. loading dose followed by continuous i.v. infusion of 0.15 microg/kg/min throughout exercise-time); 20 min after start of atropine bicycle-exercise in supine position (25, 50, 75 and 100 W for 5 min each) was performed and heart rate, contractility, blood pressure, plasma noradrenaline and plasma-renin activity were assessed. Exercise-evoked increases in all but one parameters were not different between Arg389 and Gly389 beta1-AR subjects; only plasma noradrenaline increased slightly more in Gly389 vs. Arg389 beta1-AR subjects. It appears to be unlikely that lack of Arg389Gly beta1-AR genotype-dependence of exercise-effects can be explained by influences of parasympathetic activity.

[C57BL/6 mice open field behaviour qualitatively depends on arena size].

PubMed

Lebedev, I V; Pleskacheva, M G; Anokhin, K V

2012-01-01

Open field behavior is well known to depend on physical characteristics of the apparatus. However many of such effects are poorly described especially with using of modern methods of behavioral registration and analysis. The previous results of experiments on the effect of arena size on behavior are not numerous and contradictory. We compared the behavioral scores of four groups of C57BL/6 mice in round open field arenas of four different sizes (diameter 35, 75, 150 and 220 cm). The behavior was registered and analyzed using Noldus EthoVision, WinTrack and SegmentAnalyzer software. A significant effect of arena size was found. Traveled distance and velocity increased, but not in proportion to increase of arena size. Moreover a significant effect on segment characteristics of the trajectory was revealed. Detailed behavior analysis revealed drastic differences in trajectory structure and number of rears between smaller (35 and 75 cm) and bigger (150 and 220 cm) arenas. We conclude, that the character of exploration in smaller and bigger arenas depends on relative size of central open zone in arena. Apparently its extension increases the motivational heterogeneity of space, that requires another than in smaller arenas, strategy of exploration.

Modulation of morphine antinociceptive tolerance and physical dependence by co-administration of simvastatin.

PubMed

Mansouri, Mohammad Taghi; Khodayar, Mohammad Javad; Tabatabaee, Amirhossein; Ghorbanzadeh, Behnam; Naghizadeh, Bahareh

2015-10-01

Statins, 3-hydroxy-3-methylglutaryl co-enzyme A (HMG-CoA) reductase inhibitors, are widely used in the management of different diseases beyond their primary indication for lowering cholesterol. Previous studies have demonstrated the neuroprotective effects of simvastatin in different animal models. In the present study, we examined the effects of simvastatin (30, 60, 100 and 300mg/kg, p.o.) on the development and expression of morphine-induced tolerance and dependence in mice. For the induction of morphine tolerance and dependence, mice were twice daily treated with morphine (10mg/kg, s.c.) for 5 consecutive days. Tolerance was evaluated by the hot-plate test and physical dependence by naloxone challenge, on the sixth day. The results showed that oral administration of simvastatin produced antinociceptive activity in a dose-dependent way. Co-administration of simvastatin with morphine did not affect the acute morphine-induced analgesia (10mg/kg, s.c.). However, repeated co-administration of simvastatin with morphine significantly attenuated the development of tolerance to the analgesic effect of morphine and inhibited the naloxone (5mg/kg, s.c.)-precipitated withdrawal signs (jumping and body weight loss). Also, simvastatin at doses of 100 and 300mg/kg attenuated the expression of morphine-induced tolerance and dependence. These data indicated that, while simvastatin can alleviate both development and expression of morphine-induced tolerance, it cannot enhance morphine-induced antinociception. Taken together, simvastatin may be used as an adjutant therapeutic agent in combination with morphine and or other opioids in patients with severe chronic pain. Copyright © 2015 Elsevier Inc. All rights reserved.

The N-terminal strand modulates immunoglobulin light chain fibrillogenesis.

PubMed

del Pozo-Yauner, Luis; Wall, Jonathan S; González Andrade, Martín; Sánchez-López, Rosana; Rodríguez-Ambriz, Sandra L; Pérez Carreón, Julio I; Ochoa-Leyva, Adrián; Fernández-Velasco, D Alejandro

2014-01-10

It has been suggested that the N-terminal strand of the light chain variable domain (V(L)) protects the molecule from aggregation by hindering spurious intermolecular contacts. We evaluated the impact of mutations in the N-terminal strand on the thermodynamic stability and kinetic of fibrillogenesis of the V(L) protein 6aJL2. Mutations in this strand destabilized the protein in a position-dependent manner, accelerating the fibrillogenesis by shortening the lag time; an effect that correlated with the extent of destabilization. In contrast, the effect on the kinetics of fibril elongation, as assessed in seeding experiments was of different nature, as it was not directly dependant on the degree of destabilization. This finding suggests different factors drive the nucleation-dependent and elongation phases of light chain fibrillogenesis. Finally, taking advantage of the dependence of the Trp fluorescence upon environment, four single Trp substitutions were made in the N-terminal strand, and changes in solvent exposure during aggregation were evaluated by acrylamide-quenching. The results suggest that the N-terminal strand is buried in the fibrillar state of 6aJL2 protein. This finding suggest a possible explanation for the modulating effect exerted by the mutations in this strand on the aggregation behavior of 6aJL2 protein. Copyright © 2013 Elsevier Inc. All rights reserved.

Heart Rate Dependency of Large Artery Stiffness.

PubMed

Tan, Isabella; Spronck, Bart; Kiat, Hosen; Barin, Edward; Reesink, Koen D; Delhaas, Tammo; Avolio, Alberto P; Butlin, Mark

2016-07-01

Carotid-femoral pulse wave velocity (cfPWV) quantifies large artery stiffness, it is used in hemodynamic research and is considered a useful cardiovascular clinical marker. cfPWV is blood pressure (BP) dependent. Intrinsic heart rate (HR) dependency of cfPWV is unknown because increasing HR is commonly accompanied by increasing BP. This study aims to quantify cfPWV dependency on acute, sympathovagal-independent changes in HR, independent of BP. Individuals (n=52, age 40-93 years, 11 female) with in situ cardiac pacemakers or cardioverter defibrillators were paced at 60, 70, 80, 90, and 100 bpm. BP and cfPWV were measured at each HR. Both cfPWV (mean [95% CI], 0.31 [0.26-0.37] m/s per 10 bpm; P<0.001) and central aortic diastolic pressure (3.78 [3.40-4.17] mm Hg/10 bpm; P<0.001) increased with HR. The HR effect on cfPWV was isolated by correcting the BP effects by 3 different methods: (1) statistically, by a linear mixed model; (2) mathematically, using an exponential relationship between BP and cross-sectional lumen area; and (3) using measured BP dependency of cfPWV derived from changes in BP induced by orthostatic changes (seated and supine) in a subset of subjects (n=17). The BP-independent effects of HR on cfPWV were quantified as 0.20 [0.11-0.28] m/s per 10 bpm (P<0.001, method 1), 0.16 [0.11-0.22] m/s per 10 bpm (P<0.001, method 2), and 0.16 [0.11-0.21] m/s per 10 bpm (P<0.001, method 3). With a mean HR dependency in the range of 0.16 to 0.20 m/s per 10 bpm, cfPWV may be considered to have minimal physiologically relevant changes for small changes in HR, but larger differences in HR must be considered as contributing to significant differences in cfPWV. © 2016 American Heart Association, Inc.

A Comparison of Two Mathematical Modeling Frameworks for Evaluating Sexually Transmitted Infection Epidemiology.

PubMed

Johnson, Leigh F; Geffen, Nathan

2016-03-01

Different models of sexually transmitted infections (STIs) can yield substantially different conclusions about STI epidemiology, and it is important to understand how and why models differ. Frequency-dependent models make the simplifying assumption that STI incidence is proportional to STI prevalence in the population, whereas network models calculate STI incidence more realistically by classifying individuals according to their partners' STI status. We assessed a deterministic frequency-dependent model approximation to a microsimulation network model of STIs in South Africa. Sexual behavior and demographic parameters were identical in the 2 models. Six STIs were simulated using each model: HIV, herpes, syphilis, gonorrhea, chlamydia, and trichomoniasis. For all 6 STIs, the frequency-dependent model estimated a higher STI prevalence than the network model, with the difference between the 2 models being relatively large for the curable STIs. When the 2 models were fitted to the same STI prevalence data, the best-fitting parameters differed substantially between models, with the frequency-dependent model suggesting more immunity and lower transmission probabilities. The fitted frequency-dependent model estimated that the effects of a hypothetical elimination of concurrent partnerships and a reduction in commercial sex were both smaller than estimated by the fitted network model, whereas the latter model estimated a smaller impact of a reduction in unprotected sex in spousal relationships. The frequency-dependent assumption is problematic when modeling short-term STIs. Frequency-dependent models tend to underestimate the importance of high-risk groups in sustaining STI epidemics, while overestimating the importance of long-term partnerships and low-risk groups.

Learning at different satiation levels reveals parallel functions for the cAMP-protein kinase A cascade in formation of long-term memory.

PubMed

Friedrich, Anke; Thomas, Ulf; Müller, Uli

2004-05-05

Learning and memory formation in intact animals is generally studied under defined parameters, including the control of feeding. We used associative olfactory conditioning of the proboscis extension response in honeybees to address effects of feeding status on processes of learning and memory formation. Comparing groups of animals with different but defined feeding status at the time of conditioning reveals new and characteristic features in memory formation. In animals fed 18 hr earlier, three-trial conditioning induces a stable memory that consists of different phases: a mid-term memory (MTM), translation-dependent early long-term memory (eLTM; 1-2 d), and a transcription-dependent late LTM (lLTM; > or =3 d). Additional feeding of a small amount of sucrose 4 hr before conditioning leads to a loss of all of these memory phases. Interestingly, the basal activity of the cAMP-dependent protein kinase A (PKA), a key player in LTM formation, differs in animals with different satiation levels. Pharmacological rescue of the low basal PKA activity in animals fed 4 hr before conditioning points to a specific function of cAMP-PKA cascade in mediating satiation-dependent memory formation. An increase in PKA activity during conditioning rescues only transcription-dependent lLTM; acquisition, MTM, and eLTM are still impaired. Thus, during conditioning, the cAMP-PKA cascade mediates the induction of the transcription-dependent lLTM, depending on the satiation level. This result provides the first evidence for a central and distinct function of the cAMP-PKA cascade connecting satiation level with learning.

Breaking Habits: The Effect of The French Vending Machine Ban on School Snacking and Sugar Intakes

ERIC Educational Resources Information Center

Capacci, Sara; Mazzocchi, Mario; Shankar, Bhavani

2018-01-01

This paper estimates the effect of the 2005 vending machine ban in French secondary schools on nutrient intakes and on the frequency of morning snacking at school. Using data before and after the ban, and exploiting the discontinuity associated with the age-dependent exposure to the ban, we specify a difference-in-differences regression…

Radiation Environment Effects on Spacecraft

NASA Technical Reports Server (NTRS)

Ladbury, Ray.

2017-01-01

Space poses a variety of radiation hazards. These hazards pose different risks for different missions depending on the mission environment, duration and requirements. This presentation presents a brief look at several radiation related hazards, including destructive and nondestructive Single-Event Effect, Total Ionizing Dose, Displacement Damage and Spacecraft Charging. The temporal and spatial characteristics for the environments of concern for each are considered.

Aggression among male alcohol-dependent inpatients who smoke cigarettes.

PubMed

Saatcioglu, Omer; Erim, Rahsan

2009-12-01

The authors aimed to explore the relation between nicotine dependence and the severity of aggression among Turkish male alcohol-dependent inpatients who smoked cigarettes, as well as the effect of aggression in these groups. Participants were 126 male alcohol-dependent inpatients who were given the Structured Clinical Interview for DSM-IV, Substance Use Disorder Module (A. Corapcioglu, O. Aydemir, & M. Yildiz, 1999; M. B. First, R. L. Spitzer, & J. B. W. Williams, 1997), the Fagerstrom Test for Nicotine Dependence (K. O. Fagerstrom, 1978), and the Overt Aggression Scale (OAS; S. C. Yudofsky, J. M. Silver, W. Jackson, J. Endicott, & D. Williams, 1986). The authors found differences between male alcohol-dependent inpatients with nicotine dependence (n = 94) and those with nondependence (n = 32) in OAS subtypes. The authors' findings showed that smoking cigarettes-an addiction frequently observed with alcoholism-was positively correlated with aggressive behaviors. The authors suggest that smoking cigarettes may cause aggression or aggression may cause smoking. Observing and evaluating how aggression and smoking cigarettes are associated with alcohol dependence may help relapse prevention and improve effectiveness of treatment interventions in alcoholism.

Effect of the soil type on the microbiome in the rhizosphere of field-grown lettuce.

PubMed

Schreiter, Susanne; Ding, Guo-Chun; Heuer, Holger; Neumann, Günter; Sandmann, Martin; Grosch, Rita; Kropf, Siegfried; Smalla, Kornelia

2014-01-01

The complex and enormous diversity of microorganisms associated with plant roots is important for plant health and growth and is shaped by numerous factors. This study aimed to unravel the effects of the soil type on bacterial communities in the rhizosphere of field-grown lettuce. We used an experimental plot system with three different soil types that were stored at the same site for 10 years under the same agricultural management to reveal differences directly linked to the soil type and not influenced by other factors such as climate or cropping history. Bulk soil and rhizosphere samples were collected 3 and 7 weeks after planting. The analysis of 16S rRNA gene fragments amplified from total community DNA by denaturing gradient gel electrophoresis and pyrosequencing revealed soil type dependent differences in the bacterial community structure of the bulk soils and the corresponding rhizospheres. The rhizosphere effect differed depending on the soil type and the plant growth developmental stage. Despite the soil type dependent differences in the bacterial community composition several genera such as Sphingomonas, Rhizobium, Pseudomonas, and Variovorax were significantly increased in the rhizosphere of lettuce grown in all three soils. The number of rhizosphere responders was highest 3 weeks after planting. Interestingly, in the soil with the highest numbers of responders the highest shoot dry weights were observed. Heatmap analysis revealed that many dominant operational taxonomic units were shared among rhizosphere samples of lettuce grown in diluvial sand, alluvial loam, and loess loam and that only a subset was increased in relative abundance in the rhizosphere compared to the corresponding bulk soil. The findings of the study provide insights into the effect of soil types on the rhizosphere microbiome of lettuce.

Effect of the soil type on the microbiome in the rhizosphere of field-grown lettuce

PubMed Central

Schreiter, Susanne; Ding, Guo-Chun; Heuer, Holger; Neumann, Günter; Sandmann, Martin; Grosch, Rita; Kropf, Siegfried; Smalla, Kornelia

2014-01-01

The complex and enormous diversity of microorganisms associated with plant roots is important for plant health and growth and is shaped by numerous factors. This study aimed to unravel the effects of the soil type on bacterial communities in the rhizosphere of field-grown lettuce. We used an experimental plot system with three different soil types that were stored at the same site for 10 years under the same agricultural management to reveal differences directly linked to the soil type and not influenced by other factors such as climate or cropping history. Bulk soil and rhizosphere samples were collected 3 and 7 weeks after planting. The analysis of 16S rRNA gene fragments amplified from total community DNA by denaturing gradient gel electrophoresis and pyrosequencing revealed soil type dependent differences in the bacterial community structure of the bulk soils and the corresponding rhizospheres. The rhizosphere effect differed depending on the soil type and the plant growth developmental stage. Despite the soil type dependent differences in the bacterial community composition several genera such as Sphingomonas, Rhizobium, Pseudomonas, and Variovorax were significantly increased in the rhizosphere of lettuce grown in all three soils. The number of rhizosphere responders was highest 3 weeks after planting. Interestingly, in the soil with the highest numbers of responders the highest shoot dry weights were observed. Heatmap analysis revealed that many dominant operational taxonomic units were shared among rhizosphere samples of lettuce grown in diluvial sand, alluvial loam, and loess loam and that only a subset was increased in relative abundance in the rhizosphere compared to the corresponding bulk soil. The findings of the study provide insights into the effect of soil types on the rhizosphere microbiome of lettuce. PMID:24782839

Plant traits determine the phylogenetic structure of arbuscular mycorrhizal fungal communities.

PubMed

López-García, Álvaro; Varela-Cervero, Sara; Vasar, Martti; Öpik, Maarja; Barea, José M; Azcón-Aguilar, Concepción

2017-12-01

Functional diversity in ecosystems has traditionally been studied using aboveground plant traits. Despite the known effect of plant traits on the microbial community composition, their effects on the microbial functional diversity are only starting to be assessed. In this study, the phylogenetic structure of arbuscular mycorrhizal (AM) fungal communities associated with plant species differing in life cycle and growth form, that is, plant life forms, was determined to unravel the effect of plant traits on the functional diversity of this fungal group. The results of the 454 pyrosequencing showed that the AM fungal community composition differed across plant life forms and this effect was dependent on the soil collection date. Plants with ruderal characteristics tended to associate with phylogenetically clustered AM fungal communities. By contrast, plants with resource-conservative traits associated with phylogenetically overdispersed AM fungal communities. Additionally, the soil collected in different seasons yielded AM fungal communities with different phylogenetic dispersion. In summary, we found that the phylogenetic structure, and hence the functional diversity, of AM fungal communities is dependent on plant traits. This finding adds value to the use of plant traits for the evaluation of belowground ecosystem diversity, functions and processes. © 2017 John Wiley & Sons Ltd.

Antioxidant properties of Mediterranean food plant extracts: geographical differences.

PubMed

Schaffer, S; Schmitt-Schillig, S; Müller, W E; Eckert, G P

2005-03-01

Locally grown, wild food plants seasonally contribute a considerable portion of the daily diet in certain Mediterranean areas and it has been suggested that the beneficial effects of the Mediterranean diet on human health partly originate from the antioxidant effect of flavonoid-rich food plants. The nutrient content of most wild plants is higher than that of cultivated ones and may vary depending on the prevailing environmental conditions. Accordingly, three local Mediterranean plant foods (i.e. Cichorium intybus, Sonchus oleraceus, Papaver rhoeas) were collected in Greece (Crete), southern Italy, and southern Spain in order to assess possible differences in their in vitro antioxidant potential. The biological assays revealed diverse intra-plant specific antioxidant effects for the tested extracts ranging from no activity to almost complete protection. Furthermore, substantial differences in the polyphenol content were found for the nutritionally used part of the same plant originating from different locations. However, no clear correlations between the polyphenol content and the extracts' antioxidant activities were found. Taken together, the data suggest that certain local Mediterranean plant foods possess promising antioxidant activity and that the observed biological effects are possibly influenced by the geographically-dependent environmental conditions prevailing during plant growth.

Discontinuities in effective permeability due to fracture percolation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hyman, Jeffrey De'Haven; Karra, Satish; Carey, James William

Motivated by a triaxial coreflood experiment with a sample of Utica shale where an abrupt jump in permeability was observed, possibly due to the creation of a percolating fracture network through the sample, we perform numerical simulations based on the experiment to characterize how the effective permeability of otherwise low-permeability porous media depends on fracture formation, connectivity, and the contrast between the fracture and matrix permeabilities. While a change in effective permeability due to fracture formation is expected, the dependence of its magnitude upon the contrast between the matrix permeability and fracture permeability and the fracture network structure is poorlymore » characterized. We use two different high-fidelity fracture network models to characterize how effective permeability changes as percolation occurs. The first is a dynamic two-dimensional fracture propagation model designed to mimic the laboratory settings of the experiment. The second is a static three-dimensional discrete fracture network (DFN) model, whose fracture and network statistics are based on the fractured sample of Utica shale. Once the network connects the inflow and outflow boundaries, the effective permeability increases non-linearly with network density. In most networks considered, a jump in the effective permeability was observed when the embedded fracture network percolated. We characterize how the magnitude of the jump, should it occur, depends on the contrast between the fracture and matrix permeabilities. For small contrasts between the matrix and fracture permeabilities the change is insignificant. However, for larger contrasts, there is a substantial jump whose magnitude depends non-linearly on the difference between matrix and fracture permeabilities. A power-law relationship between the size of the jump and the difference between the matrix and fracture permeabilities is observed. In conclusion, the presented results underscore the importance of fracture network topology on the upscaled properties of the porous medium in which it is embedded.« less

Discontinuities in effective permeability due to fracture percolation

DOE PAGES

Hyman, Jeffrey De'Haven; Karra, Satish; Carey, James William; ...

2018-01-31

Motivated by a triaxial coreflood experiment with a sample of Utica shale where an abrupt jump in permeability was observed, possibly due to the creation of a percolating fracture network through the sample, we perform numerical simulations based on the experiment to characterize how the effective permeability of otherwise low-permeability porous media depends on fracture formation, connectivity, and the contrast between the fracture and matrix permeabilities. While a change in effective permeability due to fracture formation is expected, the dependence of its magnitude upon the contrast between the matrix permeability and fracture permeability and the fracture network structure is poorlymore » characterized. We use two different high-fidelity fracture network models to characterize how effective permeability changes as percolation occurs. The first is a dynamic two-dimensional fracture propagation model designed to mimic the laboratory settings of the experiment. The second is a static three-dimensional discrete fracture network (DFN) model, whose fracture and network statistics are based on the fractured sample of Utica shale. Once the network connects the inflow and outflow boundaries, the effective permeability increases non-linearly with network density. In most networks considered, a jump in the effective permeability was observed when the embedded fracture network percolated. We characterize how the magnitude of the jump, should it occur, depends on the contrast between the fracture and matrix permeabilities. For small contrasts between the matrix and fracture permeabilities the change is insignificant. However, for larger contrasts, there is a substantial jump whose magnitude depends non-linearly on the difference between matrix and fracture permeabilities. A power-law relationship between the size of the jump and the difference between the matrix and fracture permeabilities is observed. In conclusion, the presented results underscore the importance of fracture network topology on the upscaled properties of the porous medium in which it is embedded.« less

Charging in the ac Conductance of a Double Barrier Resonant Tunneling Structure

NASA Technical Reports Server (NTRS)

Anantram, M. P.; Saini, Subhash (Technical Monitor)

1998-01-01

There have been many studies of the linear response ac conductance of a double barrier resonant tunneling structure (DBRTS), both at zero and finite dc biases. While these studies are important, they fail to self consistently include the effect of the time dependent charge density in the well. In this paper, we calculate the ac conductance at both zero and finite do biases by including the effect of the time dependent charge density in the well in a self consistent manner. The charge density in the well contributes to both the flow of displacement currents in the contacts and the time dependent potential in the well. We find that including these effects can make a significant difference to the ac conductance and the total ac current is not equal to the simple average of the non-selfconsistently calculated conduction currents in the two contacts. This is illustrated by comparing the results obtained with and without the effect of the time dependent charge density included correctly. Some possible experimental scenarios to observe these effects are suggested.

Combined effects of space charge and energetic disorder on photocurrent efficiency loss of field-dependent organic photovoltaic devices

NASA Astrophysics Data System (ADS)

Yoon, Sangcheol; Park, Byoungchoo; Hwang, Inchan

2015-11-01

The loss of photocurrent efficiency by space-charge effects in organic solar cells with energetic disorder was investigated to account for how energetic disorder incorporates space-charge effects, utilizing a drift-diffusion model with field-dependent charge-pair dissociation and suppressed bimolecular recombination. Energetic disorder, which induces the Poole-Frenkel behavior of charge carrier mobility, is known to decrease the mobility of charge carriers and thus reduces photovoltaic performance. We found that even if the mobilities are the same in the absence of space-charge effects, the degree of energetic disorder can be an additional parameter affecting photocurrent efficiency when space-charge effects occur. Introducing the field-dependence parameter that reflects the energetic disorder, the behavior of efficiency loss with energetic disorder can differ depending on which charge carrier is subject to energetic disorder. While the energetic disorder that is applied to higher-mobility charge carriers decreases photocurrent efficiency further, the efficiency loss can be suppressed when energetic disorder is applied to lower-mobility charge carriers.

Effects of temperature-dependent molecular absorption coefficients on the thermal infrared remote sensing of the earth surface

NASA Technical Reports Server (NTRS)

Wan, Zhengming; Dozier, Jeff

1992-01-01

The effect of temperature-dependent molecular absorption coefficients on thermal infrared spectral signatures measured from satellite sensors is investigated by comparing results from the atmospheric transmission and radiance codes LOWTRAN and MODTRAN and the accurate multiple scattering radiative transfer model ATRAD for different atmospheric profiles. The sensors considered include the operational NOAA AVHRR and two research instruments planned for NASA's Earth Observing System (EOS): MODIS-N (Moderate Resolution Imaging Spectrometer-Nadir-Mode) and ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer). The difference in band transmittance is as large as 6 percent for some thermal bands within atmospheric windows and more than 30 percent near the edges of these atmospheric windows. The effect of temperature-dependent molecular absorption coefficients on satellite measurements of sea-surface temperature can exceed 0.6 K. Quantitative comparison and factor analysis indicate that more accurate measurements of molecular absorption coefficients and better radiative transfer simulation methods are needed to achieve SST accuracy of 0.3 K, as required for global numerical models of climate, and to develop land-surface temperature algorithms at the 1-K accuracy level.

Potentiation of lymphocyte proliferative responses by nickel sulfide

NASA Technical Reports Server (NTRS)

Jaramillo, A.; Sonnenfeld, G.

1992-01-01

Crystalline nickel sulfide (NiS) induced a spleen cell proliferation that resembles a mixed lymphocyte reaction (MLR). It depended on cell-cell interaction, induced high levels of interleukin-1 (IL-1) and interleukin-2 (IL-2) and the responding cell subpopulation was composed of CD4+ T lymphocytes. Furthermore, the proliferation was inhibited in a dose-dependent manner by magnesium. Crystalline NiS also increased significantly the spleen cell proliferative response to concanavalin A (Con A) and lipopolysaccharide (LPS) with magnesium potentiating the combined effects of crystalline NiS and mitogens. Interestingly, crystalline NiS did not show any effect on the induction of IL-2 by Con A. The results described herein suggest that crystalline NiS can potentiate both antigenic (MLR) and mitogenic (Con A and LPS) proliferative responses in vitro. Crystalline NiS appears to potentiate these responses by acting in the form of ionic nickel on several intracellular targets for which magnesium ions have different noncompetitive interactions. The effects of magnesium on the potentiating action of crystalline NiS are different depending upon the type of primary stimulatory signal for proliferation (mitogenic or antigenic).

Assessing the effects of cocaine dependence and pathological gambling using group-wise sparse representation of natural stimulus FMRI data.

PubMed

Ren, Yudan; Fang, Jun; Lv, Jinglei; Hu, Xintao; Guo, Cong Christine; Guo, Lei; Xu, Jiansong; Potenza, Marc N; Liu, Tianming

2017-08-01

Assessing functional brain activation patterns in neuropsychiatric disorders such as cocaine dependence (CD) or pathological gambling (PG) under naturalistic stimuli has received rising interest in recent years. In this paper, we propose and apply a novel group-wise sparse representation framework to assess differences in neural responses to naturalistic stimuli across multiple groups of participants (healthy control, cocaine dependence, pathological gambling). Specifically, natural stimulus fMRI (N-fMRI) signals from all three groups of subjects are aggregated into a big data matrix, which is then decomposed into a common signal basis dictionary and associated weight coefficient matrices via an effective online dictionary learning and sparse coding method. The coefficient matrices associated with each common dictionary atom are statistically assessed for each group separately. With the inter-group comparisons based on the group-wise correspondence established by the common dictionary, our experimental results demonstrated that the group-wise sparse coding and representation strategy can effectively and specifically detect brain networks/regions affected by different pathological conditions of the brain under naturalistic stimuli.

Effect of corneal inhomogeneity on the mechanical behavior of the eye

NASA Astrophysics Data System (ADS)

Stein, A. A.; Moiseeva, I. N.

2018-05-01

The effect of spatial inhomogeneity of the effective cornea stiffness distribution on the mechanical properties of the eye is investigated on the basis of the two-component model of the eyeball, in which the cornea is represented by a momentless deformable, linearly elastic surface and the scleral region by an elastic element that responds to changes in intraocular pressure by changes in volume. The approach used makes it possible to consider within the same model both the natural corneal inhomogeneity and mechanical consequences of local cornea weakening owing to surgical procedures. The dependences on changes in intraocular pressure of parameters that characterize deformation properties of both the cornea (apex displacement) and the eyeball as a whole (change in intraocular volume) are obtained. For moderate inhomogeneity they differ from the same dependences for the homogenous cornea with effective stiffness equal to the average value for the corresponding inhomogeneous distribution only slightly. However, if the effective stiffness amplitude is very high, corneal inhomogeneity discernibly affects the integral response of the cornea and the eyeball as a whole to changes in pressure. The effect of inhomogeneity on the data of tonometry also mainly depends on the average effective corneal stiffness. The difference between the tonometric and true pressures increases with surgical cornea weakening in the apical region for both Schiøtz and Maklakoff tonometers.

Modeling of Metal-Ferroelectric-Semiconductor Field Effect Transistors

NASA Technical Reports Server (NTRS)

Duen Ho, Fat; Macleod, Todd C.

1998-01-01

The characteristics for a MFSFET (metal-ferroelectric-semiconductor field effect transistor) is very different than a conventional MOSFET and must be modeled differently. The drain current has a hysteresis shape with respect to the gate voltage. The position along the hysteresis curve is dependent on the last positive or negative polling of the ferroelectric material. The drain current also has a logarithmic decay after the last polling. A model has been developed to describe the MFSFET drain current for both gate voltage on and gate voltage off conditions. This model takes into account the hysteresis nature of the MFSFET and the time dependent decay. The model is based on the shape of the Fermi-Dirac function which has been modified to describe the MFSFET's drain current. This is different from the model proposed by Chen et. al. and that by Wu.

Sex-Dependent Effects Of Cannabis-Induced Analgesia

PubMed Central

Cooper, Ziva D.; Haney, Margaret

2016-01-01

Background Preclinical studies demonstrate that cannabinoid-mediated antinociceptive effects vary according to sex; it is unknown if these findings extend to humans. Methods This retrospective analysis compared the analgesic, subjective and physiological effects of active cannabis (3.56 - 5.60% THC) and inactive cannabis (0.00% THC) in male (N = 21) and female (N = 21) cannabis smokers under double-blind, placebo-controlled conditions. Pain response was measured using the Cold-Pressor Test (CPT). Participants immersed their hand in cold water (4°C); times to report pain (pain sensitivity) and withdraw the hand (pain tolerance) were recorded. Subjective drug ratings were also measured. Results Among men, active cannabis significantly decreased pain sensitivity relative to inactive cannabis (p < 0.01). In women, active cannabis failed to decrease pain sensitivity relative to inactive. Active cannabis increased pain tolerance in both men women immediately after smoking (p < 0.001); a trend was observed for differences between men and women (p < 0.10). Active cannabis also increased subjective ratings of cannabis associated with abuse liability (‘Take again,’ ‘Liking,’ ‘Good drug effect’), drug strength, and ‘High’ relative to inactive in both men and women (p < 0.01). Conclusions These results indicate that in cannabis smokers, men exhibit greater cannabis-induced analgesia relative to women. These sex-dependent differences are independent of cannabis-elicited subjective effects associated with abuse-liability, which were consistent between men and women. As such, sex-dependent differences in cannabis's analgesic effects are an important consideration that warrants further investigation when considering the potential therapeutic effects of cannabinoids for pain relief. PMID:27522535

Sex-specific effects of cardiovascular risk factors on endothelium-dependent dilation and endothelin activity in middle-aged women and men.

PubMed

Brar, Vijaywant; Gill, Sartaj; Cardillo, Carmine; Tesauro, Manfredi; Panza, Julio A; Campia, Umberto

2015-01-01

Healthy middle-aged postmenopausal women have higher endothelium-dependent dilation and lower vasoconstrictor activity of endothelin-1 than men. Whether these sex-specific differences extend to patients with cardiovascular risk factors has not been investigated. The current study aimed to determine whether, in patients with cardiovascular risk factors, sex-specific differences exist in endothelium-dependent dilation and endothelin-1 activity. Forearm blood flow responses were measured by strain-gauge plethysmography during the intra-arterial infusion of acetylcholine, sodium nitroprusside, and the selective endothelin type A receptor blocker BQ-123 in 50 women and 64 men with cardiovascular risk factors. Acetylcholine and sodium nitroprusside induced a significant vasodilation in women and men alike (p < 0.01 for both). Also BQ-123 caused a significant vasodilation (p < 0.001) in both groups. The vasodilator response to acetylcholine was greater in women compared to men; however there were no differences in the response to sodium nitroprusside and BQ-123 (p = NS for both) between the two sex groups. Middle-aged women with cardiovascular risk factors have significantly higher endothelium-dependent dilation than middle-aged men; however, vascular endothelin 1 activity is similar in the two groups. These findings suggest that the presence of cardiovascular risk factors is associated with sex-specific effects on endothelium-dependent dilation but not on endothelin 1 activity. Further study is needed to confirm our findings and to characterize the mechanisms underlying this sex-specific regulation of endothelial function.

Active Brownian agents with concentration-dependent chemotactic sensitivity.

PubMed

Meyer, Marcel; Schimansky-Geier, Lutz; Romanczuk, Pawel

2014-02-01

We study a biologically motivated model of overdamped, autochemotactic Brownian agents with concentration-dependent chemotactic sensitivity. The agents in our model move stochastically and produce a chemical ligand at their current position. The ligand concentration obeys a reaction-diffusion equation and acts as a chemoattractant for the agents, which bias their motion towards higher concentrations of the dynamically altered chemical field. We explore the impact of concentration-dependent response to chemoattractant gradients on large-scale pattern formation, by deriving a coarse-grained macroscopic description of the individual-based model, and compare the conditions for emergence of inhomogeneous solutions for different variants of the chemotactic sensitivity. We focus primarily on the so-called receptor-law sensitivity, which models a nonlinear decrease of chemotactic sensitivity with increasing ligand concentration. Our results reveal qualitative differences between the receptor law, the constant chemotactic response, and the so-called log law, with respect to stability of the homogeneous solution, as well as the emergence of different patterns (labyrinthine structures, clusters, and bubbles) via spinodal decomposition or nucleation. We discuss two limiting cases, where the model can be reduced to the dynamics of single species: (I) the agent density governed by a density-dependent effective diffusion coefficient and (II) the ligand field with an effective bistable, time-dependent reaction rate. In the end, we turn to single clusters of agents, studying domain growth and determining mean characteristics of the stationary inhomogeneous state. Analytical results are confirmed and extended by large-scale GPU simulations of the individual based model.

Dissociating object-based from egocentric transformations in mental body rotation: effect of stimuli size.

PubMed

Habacha, Hamdi; Moreau, David; Jarraya, Mohamed; Lejeune-Poutrain, Laure; Molinaro, Corinne

2018-01-01

The effect of stimuli size on the mental rotation of abstract objects has been extensively investigated, yet its effect on the mental rotation of bodily stimuli remains largely unexplored. Depending on the experimental design, mentally rotating bodily stimuli can elicit object-based transformations, relying mainly on visual processes, or egocentric transformations, which typically involve embodied motor processes. The present study included two mental body rotation tasks requiring either a same-different or a laterality judgment, designed to elicit object-based or egocentric transformations, respectively. Our findings revealed shorter response times for large-sized stimuli than for small-sized stimuli only for greater angular disparities, suggesting that the more unfamiliar the orientations of the bodily stimuli, the more stimuli size affected mental processing. Importantly, when comparing size transformation times, results revealed different patterns of size transformation times as a function of angular disparity between object-based and egocentric transformations. This indicates that mental size transformation and mental rotation proceed differently depending on the mental rotation strategy used. These findings are discussed with respect to the different spatial manipulations involved during object-based and egocentric transformations.

Phylogenetic context determines the role of competition in adaptive radiation

PubMed Central

Tan, Jiaqi; Slattery, Matthew R.; Yang, Xian; Jiang, Lin

2016-01-01

Understanding ecological mechanisms regulating the evolution of biodiversity is of much interest to ecologists and evolutionary biologists. Adaptive radiation constitutes an important evolutionary process that generates biodiversity. Competition has long been thought to influence adaptive radiation, but the directionality of its effect and associated mechanisms remain ambiguous. Here, we report a rigorous experimental test of the role of competition on adaptive radiation using the rapidly evolving bacterium Pseudomonas fluorescens SBW25 interacting with multiple bacterial species that differed in their phylogenetic distance to the diversifying bacterium. We showed that the inhibitive effect of competitors on the adaptive radiation of P. fluorescens decreased as their phylogenetic distance increased. To explain this phylogenetic dependency of adaptive radiation, we linked the phylogenetic distance between P. fluorescens and its competitors to their niche and competitive fitness differences. Competitive fitness differences, which showed weak phylogenetic signal, reduced P. fluorescens abundance and thus diversification, whereas phylogenetically conserved niche differences promoted diversification. These results demonstrate the context dependency of competitive effects on adaptive radiation, and highlight the importance of past evolutionary history for ongoing evolutionary processes. PMID:27335414

Size dependence effect of carbon-based anode material on intercalation characteristics of Li-ion battery

NASA Astrophysics Data System (ADS)

Anwar, Miftahul; Jupri, Dwi Rahmat; Saraswati, Teguh Endah

2017-01-01

This work aims to study the effect of the different size of Li-ion battery anode during charging state. Carbon-Based nanomaterial using arc-discharge in a liquid which is much simpler and cheaper compared to other techniques, i.e., CVD, laser vaporization, etc. The experiment was performed using intermediate DC power supply (1300 W) to produce an arc, and commercial graphite pencils (with 5 mm diameter) as negative and positive electrodes. Deionized water mixed with ethanol was used as a heat absorber. The result shows that arc discharge in deionized water could effectively produce carbon nanomaterial (i.e., nano-onions). In addition, finite element method-based simulation of the different intercalating process of Li-ion to the different shape of the anode, i.e., bulk semi-porous and porous anode materials for battery application is also presented. The results show that intercalation of Li ions depends on the anode structure due to the different potential density at anode region. This finding will provide support for design of Li-ion battery based on carbon nanomaterial

Chronic stress and neural function: accounting for sex and age.

PubMed

Luine, V N; Beck, K D; Bowman, R E; Frankfurt, M; Maclusky, N J

2007-10-01

Cognitive responses to stress follow the temporally dependent pattern originally established by Selye (1) wherein short-term stressors elicit adaptive responses whereas continued stress (chronic) results in maladaptive changes--deleterious effects on physiological systems and impaired cognition. However, this pattern for cognitive effects appears to apply to only half the population (males) and, more specifically, to young, adult males. Females show different cognitive responses to stress. In contrast to impaired cognition in males after chronic stress, female rodents show enhanced performance on the same memory tasks after the same stress. Not only cognition, but anxiety, shows sex-dependent changes following chronic stress--stress is anxiolytic in males and anxiogenic in females. Moreover, behavioral responses to chronic stress are different in developing as well as aging subjects (both sexes) as compared to adults. In aged rats, chronic stress enhances recognition memory in both sexes, does not alter spatial memory, and anxiety effects are opposite to young adults. When pregnant dams are exposed to chronic stress, at adulthood the offspring display yet different consequences of stress on anxiety and cognition, and, in contrast to adulthood when the behavioral effects of stress are reversible, prenatal stress effects appear enduring. Changing levels of estradiol in the sexes over the lifespan appear to contribute to the differences in response to stress. Thus, theories of stress dependent modulations in CNS function--developed solely in male models, focused on peripheral physiological processes and tested in adults--may require revision when applied to a more diverse population (age- and sex-wise) at least in relation to the neural functions of cognition and anxiety. Moreover, these results suggest that other stressors and neural functions should be investigated to determine whether age, sex and gonadal hormones also have an impact.

Genetic moderators and psychiatric mediators of the link between sexual abuse and alcohol dependence.

PubMed

Copeland, William E; Magnusson, Asa; Göransson, Mona; Heilig, Markus A

2011-06-01

This study used a case-control female sample to test psychiatric mediators and genetic moderators of the effect of sexual abuse on later alcohol dependence. The study also tested differences between alcohol dependent women with or without a history of sexual abuse on variables that might affect treatment planning. A case-control design compared 192 treatment-seeking alcohol dependent women with 177 healthy population controls. All participants were assessed for alcohol-related behaviors, sexual abuse history, psychiatric problems, and personality functioning. Markers were genotyped in the CRHR1, MAO-A and OPRM1 genes. The association of sexual abuse with alcohol dependence was limited to the most severe category of sexual abuse involving anal or vaginal penetration. Of the five psychiatric disorders tested, anxiety, anorexia nervosa, and bulimia met criteria as potential mediators of the abuse-alcohol dependence association. Severe sexual abuse continued to have an independent effect on alcohol dependence status even after accounting for these potential mediators. None of the candidate genetic markers moderated the association between sexual abuse and alcohol dependence. Of alcohol dependent participants, those with a history of severe abuse rated higher on alcoholism severity, and psychiatric comorbidities. Sexual abuse is associated with later alcohol problems directly as well as through its effect on psychiatric problems. Treatment-seeking alcohol dependent women with a history of abuse have distinct features as compared to other alcohol dependent women. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Genetic Moderators and Psychiatric Mediators of the link between Sexual Abuse and Alcohol Dependence

PubMed Central

Copeland, William E.; Magnusson, Åsa; Göransson, Mona; Heilig, Markus A.

2011-01-01

Background/Objective This study used a case-control female sample to test psychiatric mediators and genetic moderators of the effect of sexual abuse on later alcohol dependence. The study also tested differences between alcohol dependent women with or without a history of sexual abuse on variables that that might affect treatment planning. Methods A case-control design compared 192 treatment-seeking alcohol dependent women with 177 healthy population controls. All participants were assessed for alcohol-related behaviors, sexual abuse history, psychiatric problems, and personality functioning. Markers were genotyped in the CRHR1, MAO-A and OPRM1 genes. Results The association of sexual abuse with alcohol dependence was limited to the most severe category of sexual abuse involving anal or vaginal penetration. Of the five psychiatric disorders tested, anxiety, anorexia nervosa, and bulimia met criteria as potential mediators of the abuse-alcohol dependence association. Severe sexual abuse continued to have an independent effect on alcohol dependence status even after accounting for these potential mediators. None of the candidate genetic markers moderated the association between sexual abuse and alcohol dependence. Of alcohol dependent participants, those with a history of severe abuse rated higher on alcoholism severity, and psychiatric comorbidities. Conclusion Sexual abuse is associated with later alcohol problems directly as well as through its effect on psychiatric problems. Treatment-seeking alcohol dependent women with a history of abuse have distinct features as compared to other alcohol dependent women. PMID:21193270

Single Machine Scheduling and Due Date Assignment with Past-Sequence-Dependent Setup Time and Position-Dependent Processing Time

PubMed Central

Zhao, Chuan-Li; Hsu, Hua-Feng

2014-01-01

This paper considers single machine scheduling and due date assignment with setup time. The setup time is proportional to the length of the already processed jobs; that is, the setup time is past-sequence-dependent (p-s-d). It is assumed that a job's processing time depends on its position in a sequence. The objective functions include total earliness, the weighted number of tardy jobs, and the cost of due date assignment. We analyze these problems with two different due date assignment methods. We first consider the model with job-dependent position effects. For each case, by converting the problem to a series of assignment problems, we proved that the problems can be solved in O(n 4) time. For the model with job-independent position effects, we proved that the problems can be solved in O(n 3) time by providing a dynamic programming algorithm. PMID:25258727

Analysis of the labor productivity of enterprises via quantile regression

NASA Astrophysics Data System (ADS)

Türkan, Semra

2017-07-01

In this study, we have analyzed the factors that affect the performance of Turkey's Top 500 Industrial Enterprises using quantile regression. The variable about labor productivity of enterprises is considered as dependent variable, the variableabout assets is considered as independent variable. The distribution of labor productivity of enterprises is right-skewed. If the dependent distribution is skewed, linear regression could not catch important aspects of the relationships between the dependent variable and its predictors due to modeling only the conditional mean. Hence, the quantile regression, which allows modelingany quantilesof the dependent distribution, including the median,appears to be useful. It examines whether relationships between dependent and independent variables are different for low, medium, and high percentiles. As a result of analyzing data, the effect of total assets is relatively constant over the entire distribution, except the upper tail. It hasa moderately stronger effect in the upper tail.

Single machine scheduling and due date assignment with past-sequence-dependent setup time and position-dependent processing time.

PubMed

Zhao, Chuan-Li; Hsu, Chou-Jung; Hsu, Hua-Feng

2014-01-01

This paper considers single machine scheduling and due date assignment with setup time. The setup time is proportional to the length of the already processed jobs; that is, the setup time is past-sequence-dependent (p-s-d). It is assumed that a job's processing time depends on its position in a sequence. The objective functions include total earliness, the weighted number of tardy jobs, and the cost of due date assignment. We analyze these problems with two different due date assignment methods. We first consider the model with job-dependent position effects. For each case, by converting the problem to a series of assignment problems, we proved that the problems can be solved in O(n(4)) time. For the model with job-independent position effects, we proved that the problems can be solved in O(n(3)) time by providing a dynamic programming algorithm.

Non-Dependent and Dependent Daily Cannabis Users Differ in Mental Health but Not Prospective Memory Ability

PubMed Central

Braidwood, Ruth; Mansell, Samantha; Waldron, Jon; Rendell, Peter G.; Kamboj, Sunjeev K.; Curran, H. Valerie

2018-01-01

Research suggests that daily cannabis users have impaired memory for past events, but it is not clear whether they are also impaired in prospective memory (PM) for future events. The present study examined PM in daily cannabis users who were either dependent (n = 18) or non-dependent (n = 18), and compared them with non-using controls (n = 18). The effect of future event simulation (FES) on PM performance was also examined. Participants were matched across groups on age, gender, and highest level of education. The virtual week (VW) was used to objectively assess PM abilities, both at baseline and following FES. Other measures used were: cannabis use variables, immediate and delayed prose recall, phonemic and category fluency, spot-the-word test (premorbid intelligence), Beck Depression Inventory, Beck Anxiety Inventory, and a measure of schizotypy (Oxford-Liverpool Inventory of Feelings and Experiences: unusual experiences subscale). No group differences were found in PM performance on the VW, and FES did not improve PM performance in any group. Dependent cannabis users scored higher on depression, anxiety, and schizotypy than both other groups with non-dependent cannabis users scoring at a similar level to controls. There were no group differences in alcohol use. Findings suggest that when carefully matched on baseline variables, and not differing in premorbid IQ or alcohol use, young, near-daily cannabis users do not differ from non-using controls in PM performance. PMID:29636705

Effects of eye-glasses, hair, headgear, and clothing on measured head-related transfer functions Part Ib

NASA Astrophysics Data System (ADS)

Riederer, Klaus A. J.

2003-10-01

Extensive head-related transfer function (HRTF) measurements show high HRTF repeatability, consequences of different measurement methods, and conditions covering the whole three-dimensional space [Riederer, J. Audio Eng. Soc. (Abstracts) 46, 1036 (1998), preprint 4846]. This study concentrates on specific effects on HRTFs carefully re-measured on the same Cortex dummy head applying Sennheiser KE4-211-2 microphones at its silicone putty blocked ear-canal entrances, employing 252 sound incidents including seven elevations. The effects of five different wigs (synthetic, natural, thick, thin, long and short hair) with varied hairstyles, four hats (cap, bicycle helmet, mens and womens trilby), clothes (alpaca pullover, bicycling drymax-jacket) and spectacles were investigated under 28 combinations. The influences are highly dependent on direction, frequency, and case. Clothes and eye-glasses affect minimally HRTF; hair has a stronger effect, depending on the actual hairdo (typically above 7 kHz). Hats alter intensively HRTFs (typically above 5 kHz), depending on the model. The measurements give deeper insight to the development of idiosyncratic features in binaural localization cues. The second part of the study addresses their perceptual effects [Riederer, J. Acoust. Soc. Am., this issue]. [Work supported by Graduate School of Electronics, Telecommunication and Automation; thanks to Finnish Broadcasting Company, Mr. Hellstrom; Mrs. Chen.

Effect of humic acid (HA) on sulfonamide sorption by biochars.

PubMed

Lian, Fei; Sun, Binbin; Chen, Xi; Zhu, Lingyan; Liu, Zhongqi; Xing, Baoshan

2015-09-01

Effect of quantity and fractionation of loaded humic acid (HA) on biochar sorption for sulfonamides was investigated. The HA was applied in two different modes, i.e. pre-coating and co-introduction with sorbate. In pre-coating mode, the polar fractions of HA tended to interact with low-temperature biochars via H-bonding, while the hydrophobic fractions were likely to be adsorbed by high-temperature biochars through hydrophobic and π-π interactions, leading to different composition and structure of the HA adlayers. The influences of HA fractionation on biochar sorption for sulfonamides varied significantly, depending on the nature of interaction between HA fraction and sorbate. Meanwhile, co-introduction of HA with sulfonamides revealed that the effect of HA on sulfonamide sorption was also dependent on HA concentration. These findings suggest that the amount and fractionation of adsorbed HA are tailored by the surface properties of underlying biochars, which differently affect the sorption for organic contaminants. Copyright © 2015 Elsevier Ltd. All rights reserved.

Environmental and biological factors influencing Culex pipiens quinquefasciatus (Diptera: Culicidae) vector competence for West Nile Virus.

PubMed

Richards, Stephanie L; Lord, Cynthia C; Pesko, Kendra N; Tabachnick, Walter J

2010-07-01

Interactions between environmental and biological factors affect the vector competence of Culex pipiens quinquefasciatus for West Nile virus. Three age cohorts from two Cx. p. quinquefasciatus colonies were fed blood containing a low- or high-virus dose, and each group was held at two different extrinsic incubation temperatures (EIT) for 13 days. The colonies differed in the way that they responded to the effects of the environment on vector competence. The effects of mosquito age on aspects of vector competence were dependent on the EIT and dose, and they changed depending on the colony. Complex interactions must be considered in laboratory studies of vector competence, because the extent of the genetic and environmental variation controlling vector competence in nature is largely unknown. Differences in the environmental (EIT and dose) and biological (mosquito age and colony) effects from previous studies of Cx. p. quinquefasciatus vector competence for St. Louis encephalitis virus are discussed.

Size and shape dependent optical properties of InAs quantum dots

NASA Astrophysics Data System (ADS)

Imran, Ali; Jiang, Jianliang; Eric, Deborah; Yousaf, Muhammad

2018-01-01

In this study Electronic states and optical properties of self assembled InAs quantum dots embedded in GaAs matrix have been investigated. Their carrier confinement energies for single quantum dot are calculated by time-independent Schrödinger equation in which hamiltonianian of the system is based on effective mass approximation and position dependent electron momentum. Transition energy, absorption coefficient, refractive index and high frequency dielectric constant for spherical, cylindrical and conical quantum dots with different sizes in different dimensions are calculated. Comparative studies have revealed that size and shape greatly affect the electronic transition energies and absorption coefficient. Peaks of absorption coefficients have been found to be highly shape dependent.

Synchrony dynamics underlying effective connectivity reconstruction of neuronal circuits

NASA Astrophysics Data System (ADS)

Yu, Haitao; Guo, Xinmeng; Qin, Qing; Deng, Yun; Wang, Jiang; Liu, Jing; Cao, Yibin

2017-04-01

Reconstruction of effective connectivity between neurons is essential for neural systems with function-related significance, characterizing directionally causal influences among neurons. In this work, causal interactions between neurons in spinal dorsal root ganglion, activated by manual acupuncture at Zusanli acupoint of experimental rats, are estimated using Granger causality (GC) method. Different patterns of effective connectivity are obtained for different frequencies and types of acupuncture. Combined with synchrony analysis between neurons, we show a dependence of effective connection on the synchronization dynamics. Based on the experimental findings, a neuronal circuit model with synaptic connections is constructed. The variation of neuronal effective connectivity with respect to its structural connectivity and synchronization dynamics is further explored. Simulation results show that reciprocally causal interactions with statistically significant are formed between well-synchronized neurons. The effective connectivity may be not necessarily equivalent to synaptic connections, but rather depend on the synchrony relationship. Furthermore, transitions of effective interaction between neurons are observed following the synchronization transitions induced by conduction delay and synaptic conductance. These findings are helpful to further investigate the dynamical mechanisms underlying the reconstruction of effective connectivity of neuronal population.

SYSTEMATIC CENTER-TO-LIMB VARIATION IN MEASURED HELIOSEISMIC TRAVEL TIMES AND ITS EFFECT ON INFERENCES OF SOLAR INTERIOR MERIDIONAL FLOWS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao Junwei; Nagashima, Kaori; Bogart, R. S.

We report on a systematic center-to-limb variation in measured helioseismic travel times, which must be taken into account for an accurate determination of solar interior meridional flows. The systematic variation, found in time-distance helioseismology analysis using SDO/HMI and SDO/AIA observations, is different in both travel-time magnitude and variation trend for different observables. It is not clear what causes this systematic effect. Subtracting the longitude-dependent east-west travel times, obtained along the equatorial area, from the latitude-dependent north-south travel times, obtained along the central meridian area, gives remarkably similar results for different observables. We suggest this as an effective procedure for removingmore » the systematic center-to-limb variation. The subsurface meridional flows obtained from inversion of the corrected travel times are approximately 10 m s{sup -1} slower than those obtained without removing the systematic effect. The detected center-to-limb variation may have important implications in the derivation of meridional flows in the deep interior and needs to be better understood.« less

Systematic Center-To-Limb Variation in Measured Helioseismic Travel Times and Its Effect on Inferences of Solar Interior Meridional Flows

NASA Technical Reports Server (NTRS)

Zhao, Junwei; Nagashima, Kaori; Bogart, R. S.; Kosovichev, Alexander; Duvall, T. L., Jr.

2012-01-01

We report on a systematic center-to-limb variation in measured helioseismic travel times, which must be taken into account for an accurate determination of solar interior meridional flows. The systematic variation, found in time-distance helioseismology analysis using SDO/HMI and SDO/AIA observations, is different in both travel-time magnitude and variation trend for different observables. It is not clear what causes this systematic effect. Subtracting the longitude-dependent east-west travel times, obtained along the equatorial area, from the latitude-dependent north-south travel times, obtained along the central meridian area, gives remarkably similar results for different observables. We suggest this as an effective procedure for removing the systematic center-to-limb variation. The subsurface meridional flows obtained from inversion of the corrected travel times are approximately 10 m s-1 slower than those obtained without removing the systematic effect. The detected center-to-limb variation may have important implications in the derivation of meridional flows in the deep interior and needs to be better understood.

Slow changing postural cues cancel visual field dependence on self-tilt detection.

PubMed

Scotto Di Cesare, C; Macaluso, T; Mestre, D R; Bringoux, L

2015-01-01

Interindividual differences influence the multisensory integration process involved in spatial perception. Here, we assessed the effect of visual field dependence on self-tilt detection relative to upright, as a function of static vs. slow changing visual or postural cues. To that aim, we manipulated slow rotations (i.e., 0.05° s(-1)) of the body and/or the visual scene in pitch. Participants had to indicate whether they felt being tilted forward at successive angles. Results show that thresholds for self-tilt detection substantially differed between visual field dependent/independent subjects, when only the visual scene was rotated. This difference was no longer present when the body was actually rotated, whatever the visual scene condition (i.e., absent, static or rotated relative to the observer). These results suggest that the cancellation of visual field dependence by dynamic postural cues may rely on a multisensory reweighting process, where slow changing vestibular/somatosensory inputs may prevail over visual inputs. Copyright © 2014 Elsevier B.V. All rights reserved.

Ethanol-Associated Changes in Glutamate Reward Neurocircuitry: A Minireview of Clinical and Preclinical Genetic Findings

PubMed Central

Bell, Richard L.; Hauser, Sheketha R.; McClintick, Jeanette; Rahman, Shafiqur; Edenberg, Howard J.; Szumlinski, Karen K.; McBride, William J.

2016-01-01

Herein, we have reviewed the role of glutamate, the major excitatory neurotransmitter in the brain, in a number of neurochemical, -physiological, and -behavioral processes mediating the development of alcohol dependence. The findings discussed include results from both preclinical as well as neuroimaging and postmortem clinical studies. Expression levels for a number of glutamate-associated genes and/or proteins are modulated by alcohol abuse and dependence. These changes in expression include metabotropic receptors and ionotropic receptor subunits as well as different glutamate transporters. Moreover, these changes in gene expression parallel the pharmacologic manipulation of these same receptors and transporters. Some of these gene expression changes may have predated alcohol abuse and dependence because a number of glutamate-associated polymorphisms are related to a genetic predisposition to develop alcohol dependence. Other glutamate-associated polymorphisms are linked to age at the onset of alcohol-dependence and initial level of response/sensitivity to alcohol. Finally, findings of innate and/or ethanol-induced glutamate-associated gene expression differences/changes observed in a genetic animal model of alcoholism, the P rat, are summarized. Overall, the existing literature indicates that changes in glutamate receptors, transporters, enzymes, and scaffolding proteins are crucial for the development of alcohol dependence and there is a substantial genetic component to these effects. This indicates that continued research into the genetic underpinnings of these glutamate-associated effects will provide important novel molecular targets for treating alcohol abuse and dependence. PMID:26809998

GeneiASE: Detection of condition-dependent and static allele-specific expression from RNA-seq data without haplotype information

PubMed Central

Edsgärd, Daniel; Iglesias, Maria Jesus; Reilly, Sarah-Jayne; Hamsten, Anders; Tornvall, Per; Odeberg, Jacob; Emanuelsson, Olof

2016-01-01

Allele-specific expression (ASE) is the imbalance in transcription between maternal and paternal alleles at a locus and can be probed in single individuals using massively parallel DNA sequencing technology. Assessing ASE within a single sample provides a static picture of the ASE, but the magnitude of ASE for a given transcript may vary between different biological conditions in an individual. Such condition-dependent ASE could indicate a genetic variation with a functional role in the phenotypic difference. We investigated ASE through RNA-sequencing of primary white blood cells from eight human individuals before and after the controlled induction of an inflammatory response, and detected condition-dependent and static ASE at 211 and 13021 variants, respectively. We developed a method, GeneiASE, to detect genes exhibiting static or condition-dependent ASE in single individuals. GeneiASE performed consistently over a range of read depths and ASE effect sizes, and did not require phasing of variants to estimate haplotypes. We observed condition-dependent ASE related to the inflammatory response in 19 genes, and static ASE in 1389 genes. Allele-specific expression was confirmed by validation of variants through real-time quantitative RT-PCR, with RNA-seq and RT-PCR ASE effect-size correlations r = 0.67 and r = 0.94 for static and condition-dependent ASE, respectively. PMID:26887787

Lack of renewal effect in extinction of naturally acquired conditioned eyeblink responses, but possible dependency on physical context.

PubMed

Claassen, J; Mazilescu, L; Thieme, A; Bracha, V; Timmann, D

2016-01-01

Context dependency of extinction is well known and has extensively been studied in fear conditioning, but has rarely been assessed in eyeblink conditioning. One way to demonstrate context dependency of extinction is the renewal effect. ABA paradigms are most commonly used to show the renewal effect of extinguished learned fear: if acquisition takes place in context A, and extinction takes place in context B (extinction phase), learned responses will recover in subsequent extinction trials presented in context A (renewal phase). The renewal effect of the visual threat eyeblink response (VTER), a conditioned eyeblink response, which is naturally acquired in early infancy, was examined in a total of 48 young and healthy participants with two experiments using an ABA paradigm. Twenty paired trials were performed in context A (baseline trials), followed by 50 extinction trials in context B (extinction phase) and 50 extinction trials in context A (renewal phase). In 24 participants, contexts A and B were two different rooms, and in the other 24 participants, two different background colors (orange and blue) and noises were used. To rule out spontaneous recovery, an AAA design was used for comparison. There were significant effects of extinction in both experiments. No significant renewal effects were observed. In experiment 2, however, extinction was significantly less using orange background during extinction compared to the blue background. The present findings suggest that extinction of conditioned eyeblinks depends on the physical context. Findings add to the animal literature that context can play a role in the acquisition of classically conditioned eyeblink responses. Future studies, however, need to be performed to confirm the present findings. Lack of renewal effect may be explained by the highly overlearned character of the VTER.

Empirical study of the dependence of the results of multivariable flexible survival analyses on model selection strategy.

PubMed

Binquet, C; Abrahamowicz, M; Mahboubi, A; Jooste, V; Faivre, J; Bonithon-Kopp, C; Quantin, C

2008-12-30

Flexible survival models, which avoid assumptions about hazards proportionality (PH) or linearity of continuous covariates effects, bring the issues of model selection to a new level of complexity. Each 'candidate covariate' requires inter-dependent decisions regarding (i) its inclusion in the model, and representation of its effects on the log hazard as (ii) either constant over time or time-dependent (TD) and, for continuous covariates, (iii) either loglinear or non-loglinear (NL). Moreover, 'optimal' decisions for one covariate depend on the decisions regarding others. Thus, some efficient model-building strategy is necessary.We carried out an empirical study of the impact of the model selection strategy on the estimates obtained in flexible multivariable survival analyses of prognostic factors for mortality in 273 gastric cancer patients. We used 10 different strategies to select alternative multivariable parametric as well as spline-based models, allowing flexible modeling of non-parametric (TD and/or NL) effects. We employed 5-fold cross-validation to compare the predictive ability of alternative models.All flexible models indicated significant non-linearity and changes over time in the effect of age at diagnosis. Conventional 'parametric' models suggested the lack of period effect, whereas more flexible strategies indicated a significant NL effect. Cross-validation confirmed that flexible models predicted better mortality. The resulting differences in the 'final model' selected by various strategies had also impact on the risk prediction for individual subjects.Overall, our analyses underline (a) the importance of accounting for significant non-parametric effects of covariates and (b) the need for developing accurate model selection strategies for flexible survival analyses. Copyright 2008 John Wiley & Sons, Ltd.

Pavlovian-to-instrumental transfer in alcohol dependence: a pilot study.

PubMed

Garbusow, Maria; Schad, Daniel J; Sommer, Christian; Jünger, Elisabeth; Sebold, Miriam; Friedel, Eva; Wendt, Jean; Kathmann, Norbert; Schlagenhauf, Florian; Zimmermann, Ulrich S; Heinz, Andreas; Huys, Quentin J M; Rapp, Michael A

2014-01-01

Pavlovian processes are thought to play an important role in the development, maintenance and relapse of alcohol dependence, possibly by influencing and usurping ongoing thought and behavior. The influence of pavlovian stimuli on ongoing behavior is paradigmatically measured by pavlovian-to-instrumental transfer (PIT) tasks. These involve multiple stages and are complex. Whether increased PIT is involved in human alcohol dependence is uncertain. We therefore aimed to establish and validate a modified PIT paradigm that would be robust, consistent and tolerated by healthy controls as well as by patients suffering from alcohol dependence, and to explore whether alcohol dependence is associated with enhanced PIT. Thirty-two recently detoxified alcohol-dependent patients and 32 age- and gender-matched healthy controls performed a PIT task with instrumental go/no-go approach behaviors. The task involved both pavlovian stimuli associated with monetary rewards and losses, and images of drinks. Both patients and healthy controls showed a robust and temporally stable PIT effect. Strengths of PIT effects to drug-related and monetary conditioned stimuli were highly correlated. Patients more frequently showed a PIT effect, and the effect was stronger in response to aversively conditioned CSs (conditioned suppression), but there was no group difference in response to appetitive CSs. The implementation of PIT has favorably robust properties in chronic alcohol-dependent patients and in healthy controls. It shows internal consistency between monetary and drug-related cues. The findings support an association of alcohol dependence with an increased propensity towards PIT. © 2014 S. Karger AG, Basel.

Precise calculation of neutron-capture reactions contribution in energy release for different types of VVER-1000 fuel assemblies

NASA Astrophysics Data System (ADS)

Tikhomirov, Georgy; Bahdanovich, Rynat; Pham, Phu

2017-09-01

Precise calculation of energy release in a nuclear reactor is necessary to obtain the correct spatial power distribution and predict characteristics of burned nuclear fuel. In this work, previously developed method for calculation neutron-capture reactions - capture component - contribution in effective energy release in a fuel core of nuclear reactor is discussed. The method was improved and implemented to the different models of VVER-1000 reactor developed for MCU 5 and MCNP 4 computer codes. Different models of equivalent cell and fuel assembly in the beginning of fuel cycle were calculated. These models differ by the geometry, fuel enrichment and presence of burnable absorbers. It is shown, that capture component depends on fuel enrichment and presence of burnable absorbers. Its value varies for different types of hot fuel assemblies from 3.35% to 3.85% of effective energy release. Average capture component contribution in effective energy release for typical serial fresh fuel of VVER-1000 is 3.5%, which is 7 MeV/fission. The method will be used in future to estimate the dependency of capture energy on fuel density, burn-up, etc.

Effects of seasonal change and experimental warming on the temperature dependence of photosynthesis in the canopy leaves of Quercus serrata.

PubMed

Yamaguchi, Daisuke P; Nakaji, Tatsuro; Hiura, Tsutom; Hikosaka, Kouki

2016-10-01

The effects of warming on the temperature response of leaf photosynthesis have become an area of major concern in recent decades. Although growth temperature (GT) and day length (DL) affect leaf gas exchange characteristics, the way in which these factors influence the temperature dependence of photosynthesis remains uncertain. We established open-top canopy chambers at the canopy top of a deciduous forest, in which average daytime leaf temperature was increased by 1.0 °C. We conducted gas exchange measurements for the canopy leaves of deciduous trees exposed to artificial warming during different seasons. The carbon dioxide assimilation rate at 20 °C (A 20 ) was not affected by warming, whereas that at 25 °C (A 25 ) tended to be higher in leaves exposed to warming. Warming increased the optimal temperature of photosynthesis by increasing the activation energy for the maximum rate of carboxylation. Regression analysis indicated that both GT and DL strongly influenced gas exchange characteristics. Sensitivity analysis revealed that DL affected A without obvious effects on the temperature dependence of A, whereas GT almost maintained constant A 20 and strongly influenced the temperature dependence. These results indicate that GT and DL have different influences on photosynthesis; GT and DL affect the 'slope' and intercept' of the temperature dependence of photosynthesis, respectively. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Age-dependent differences in nicotine reward and withdrawal in female mice.

PubMed

Kota, D; Martin, B R; Damaj, M I

2008-06-01

Adolescent smoking is an increasing epidemic in the US. Research has shown that the commencement of smoking at a young age increases addiction and decreases the probability of successful cessation; however, limited work has focused on nicotine dependence in the female. The goal of the present study was to identify the biological and behavioral factors that may contribute to nicotine's increased abuse liability in female adolescents using animal models of nicotine dependence. Early adolescent (PND 28) and adult (PND 70) female mice were compared in various aspects of nicotine dependence using reward and withdrawal models following sub-chronic nicotine exposure. Furthermore, in vivo acute sensitivity and tolerance to nicotine were examined. In the conditioned place preference model, adolescents demonstrated a significant preference at 0.5 mg/kg nicotine, an inactive dose in adults. Adults found higher doses (0.7 and 1.0 mg/kg) of nicotine to elicit rewarding effects. Furthermore, adolescents displayed increased physical, but not affective, withdrawal signs in three models. Upon acute exposure to nicotine, adolescent mice showed increased sensitivity in an analgesic measure as well as hypothermia. After chronic nicotine exposure, both adults and adolescents displayed tolerance to nicotine with adolescents having a lower degree of tolerance to changes in body temperature. These data indicate that differences in nicotine's rewarding and aversive effects may contribute to variations in certain components of nicotine dependence between adult and adolescent female mice. Furthermore, this implies that smoking cessation therapies may not be equally effective across all ages.

Characterisation of an ion source on the Helix MC Plus noble gas mass spectrometer - pressure dependent mass discrimination

NASA Astrophysics Data System (ADS)

Zhang, X.

2017-12-01

Characterisation of an ion source on the Helix MC Plusnoble gas mass spectrometer - pressure dependent mass discrimination Xiaodong Zhang* dong.zhang@anu.edu.au Masahiko Honda Masahiko.honda@anu.edu.au Research School of Earth Sciences, The Australian National University, Canberra, Australia To obtain reliable measurements of noble gas elemental and isotopic abundances in a geological sample it is essential that the mass discrimination (instrument-induced isotope fractionation) of the mass spectrometer remain constant over the working range of noble gas partial pressures. It is known, however, that there are pressure-dependent variations in sensitivity and mass discrimination in conventional noble gas mass spectrometers [1, 2, 3]. In this study, we discuss a practical approach to ensuring that the pressure effect in the Helix MC Plus high resolution, multi-collector noble gas mass spectrometer is minimised. The isotopic composition of atmospheric Ar was measured under a range of operating conditions to test the effects of different parameters on Ar mass discrimination. It was found that the optimised ion source conditions for pressure independent mass discrimination for Ar were different from those for maximised Ar sensitivity. The optimisation can be achieved by mainly adjusting the repeller voltage. It is likely that different ion source settings will be required to minimise pressure-dependent mass discrimination for different noble gases. A recommended procedure for tuning an ion source to reduce pressure dependent mass discrimination will be presented. References: Honda M., et al., Geochim. Cosmochim. Acta, 57, 859 -874, 1993. Burnard P. G., and Farley K. A., Geochemistry Geophysics Geosystems, Volume 1, 2000GC00038, 2000. Mabry J., et al., Journal of Analytical Atomic Spectrometry, 27, 1012 - 1017, 2012.

Material dependence of 2H(d,p)3H cross section at the very low energies

NASA Astrophysics Data System (ADS)

Kılıç, Ali İhsan; Czerski, Konrad; Kuştan-Kılıç, Fadime; Targosz-Sleczka, Natalia; Weissbach, Daniel; Huke, Armin; Ruprecht, Götz

2017-09-01

Calculations of the material dependence of 2H(d,p)3H cross section and neutron-to-proton branching ratio of d+d reactions have been performed including a concept of the 0+ threshold single particle resonance. The resonance has been assumed to explain the enhanced electron screening effect observed in the d+d reaction for different metallic targets. Here, we have included interference effects between the flat and resonance part of the cross section, which allowed us to enlighten observed suppression of the neutron channel in some metals such as Sr and Li. Since the position of the resonance depends on the screening energy that strongly depends on the local electron density. The resonance width, observed for the d+d reactions in the very hygroscopic metals (Sr and Li) and therefore probably contaminated by oxides, should be much larger than for other metals. Thus, the interference term of the cross section depending on the total resonance width provides the material dependences.

Results on asymptotic behaviour for discrete, two-patch metapopulations with density-dependent selection

Treesearch

James F. Selgrade; James H. Roberds

2005-01-01

A 4-dimensional system of nonlinear difference equations tracking allele frequencies and population sizes for a two-patch metapopulation model is studied. This system describes intergenerational changes brought about by density-dependent selection within patches and moderated by the effects of migration between patches. To determine conditions which result in similar...

An Exploratory Study of the Role of Task Dependence on Team Captains' Leadership Development

ERIC Educational Resources Information Center

Grandzol, Christian J.

2011-01-01

While there is evidence that team captainship in intercollegiate sports can lead to leadership development, there is little evidence about the role that task dependence may play on that effect. The individual or team nature of sports may offer different leadership experiences for team captains, leading to differential outcomes. In this exploratory…

The Two Faces of Social Interaction Reward in Animal Models of Drug Dependence

PubMed Central

Rawas, Rana El

2016-01-01

Drug dependence is a serious health and social problem. Social factors can modify vulnerability to developing drug dependence, acting as risk factors or protective factors. Whereas stress and peer environment that encourage substance use may increase drug taking, strong attachments between family members and peer environment that do not experience drug use may protect against drug taking and, ultimately, drug dependence. The rewarding effects of drug abuse and social interaction can be evaluated using animal models. In this review we focus on evaluating social interaction reward in the conditioned place preference paradigm. We give an overview of how social interaction, if made available within the drug context, may facilitate, promote and interact with the drug’s effects. However, social interaction, if offered alternatively outside the drug context, may have pronounced protective effects against drug abuse and relapse. We also address the importance of the weight difference parameter between the social partners in determining the positive or “agonistic” versus the hostile or “antagonistic” social interaction. We conclude that understanding social interaction reward and its subsequent effects on drug reward is sorely needed for therapeutic interventions against drug dependence. PMID:26088685

Constraints on the near-Earth asteroid obliquity distribution from the Yarkovsky effect

NASA Astrophysics Data System (ADS)

Tardioli, C.; Farnocchia, D.; Rozitis, B.; Cotto-Figueroa, D.; Chesley, S. R.; Statler, T. S.; Vasile, M.

2017-12-01

Aims: From light curve and radar data we know the spin axis of only 43 near-Earth asteroids. In this paper we attempt to constrain the spin axis obliquity distribution of near-Earth asteroids by leveraging the Yarkovsky effect and its dependence on an asteroid's obliquity. Methods: By modeling the physical parameters driving the Yarkovsky effect, we solve an inverse problem where we test different simple parametric obliquity distributions. Each distribution results in a predicted Yarkovsky effect distribution that we compare with a χ2 test to a dataset of 125 Yarkovsky estimates. Results: We find different obliquity distributions that are statistically satisfactory. In particular, among the considered models, the best-fit solution is a quadratic function, which only depends on two parameters, favors extreme obliquities consistent with the expected outcomes from the YORP effect, has a 2:1 ratio between retrograde and direct rotators, which is in agreement with theoretical predictions, and is statistically consistent with the distribution of known spin axes of near-Earth asteroids.

Excitation power dependence of photoluminescence spectra of GaSb type-II quantum dots in GaAs grown by droplet epitaxy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kawazu, T., E-mail: KAWAZU.Takuya@nims.go.jp; Noda, T.; Sakuma, Y.

2016-04-15

We investigated the excitation power P dependence of photoluminescence (PL) spectra of GaSb type-II quantum dots (QDs) in GaAs grown by droplet epitaxy. We prepared two QD samples annealed at slightly different temperatures (380 {sup o}C and 400 {sup o}C) and carried out PL measurements. The 20 {sup o}C increase of the annealing temperature leads to (1) about 140 and 60 times stronger wetting layer (WL) luminescence at low and high P, (2) about 45% large energy shift of QD luminescence with P, and (3) the different P dependence of the PL intensity ratio between the QD and the WL. These differences ofmore » the PL characteristics are explained by the effects of the WL.« less

Effects of the source of social comparison information on former cancer patients' quality of life.

PubMed

Brakel, Thecla M; Dijkstra, Arie; Buunk, Abraham P

2012-11-01

Life, following curative treatment, can be a struggle for former cancer patients. In this phase of their illness, social comparison information may help to improve a patient's quality of life (QOL). The objective of this study was to determine whether the effects of this information depend on the following two variables: (1) the individual's physical health and (2) the individual's sensitivity to social comparison. In the current study, the effects on a patient's QOL were tested that occur when they are listening to a psychological oncological expert talking about cancer patients' experiences. Three different recorded interviews with experts were compared (on negative emotions, effective coping, or both), and individual differences were tested as moderators. In addition, the expert source conditions were compared with a condition in which the source was not an expert but a former patient. In a randomized field experiment, 154 Dutch former cancer patients (M(age) = 55 years; 68% women) were assigned to one of the four conditions (three expert source and one former patient source condition). QOL was assessed after 2 months. The effects of the expert source conditions on QOL depended on the participants' physical health (good vs. poor) and on the participants' sensitivity to social comparison (whether the recipient reacts with contrast or identification), as indicated by significant three-way interactions (p < .001). Depending on these two variables, one of the three expert source conditions was at least as effective as the former patient source condition. The results show that desired and undesired effects are found when individual differences relevant to the processing of intervention information are examined. ©2012 The British Psychological Society.

Genetics of Amino Acid Taste and Appetite.

PubMed

Bachmanov, Alexander A; Bosak, Natalia P; Glendinning, John I; Inoue, Masashi; Li, Xia; Manita, Satoshi; McCaughey, Stuart A; Murata, Yuko; Reed, Danielle R; Tordoff, Michael G; Beauchamp, Gary K

2016-07-01

The consumption of amino acids by animals is controlled by both oral and postoral mechanisms. We used a genetic approach to investigate these mechanisms. Our studies have shown that inbred mouse strains differ in voluntary amino acid consumption, and these differences depend on sensory and nutritive properties of amino acids. Like humans, mice perceive some amino acids as having a sweet (sucrose-like) taste and others as having an umami (glutamate-like) taste. Mouse strain differences in the consumption of some sweet-tasting amino acids (d-phenylalanine, d-tryptophan, and l-proline) are associated with polymorphisms of a taste receptor, type 1, member 3 gene (Tas1r3), and involve differential peripheral taste responsiveness. Strain differences in the consumption of some other sweet-tasting amino acids (glycine, l-alanine, l-glutamine, and l-threonine) do not depend on Tas1r3 polymorphisms and so must be due to allelic variation in other, as yet unknown, genes involved in sweet taste. Strain differences in the consumption of l-glutamate may depend on postingestive rather than taste mechanisms. Thus, genes and physiologic mechanisms responsible for strain differences in the consumption of each amino acid depend on the nature of its taste and postingestive properties. Overall, mouse strain differences in amino acid taste and appetite have a complex genetic architecture. In addition to the Tas1r3 gene, these differences depend on other genes likely involved in determining the taste and postingestive effects of amino acids. The identification of these genes may lead to the discovery of novel mechanisms that regulate amino acid taste and appetite. © 2016 American Society for Nutrition.

Genetics of Amino Acid Taste and Appetite123

PubMed Central

Bosak, Natalia P; Glendinning, John I; Inoue, Masashi; Li, Xia; Manita, Satoshi; McCaughey, Stuart A; Murata, Yuko; Beauchamp, Gary K

2016-01-01

The consumption of amino acids by animals is controlled by both oral and postoral mechanisms. We used a genetic approach to investigate these mechanisms. Our studies have shown that inbred mouse strains differ in voluntary amino acid consumption, and these differences depend on sensory and nutritive properties of amino acids. Like humans, mice perceive some amino acids as having a sweet (sucrose-like) taste and others as having an umami (glutamate-like) taste. Mouse strain differences in the consumption of some sweet-tasting amino acids (d-phenylalanine, d-tryptophan, and l-proline) are associated with polymorphisms of a taste receptor, type 1, member 3 gene (Tas1r3), and involve differential peripheral taste responsiveness. Strain differences in the consumption of some other sweet-tasting amino acids (glycine, l-alanine, l-glutamine, and l-threonine) do not depend on Tas1r3 polymorphisms and so must be due to allelic variation in other, as yet unknown, genes involved in sweet taste. Strain differences in the consumption of l-glutamate may depend on postingestive rather than taste mechanisms. Thus, genes and physiologic mechanisms responsible for strain differences in the consumption of each amino acid depend on the nature of its taste and postingestive properties. Overall, mouse strain differences in amino acid taste and appetite have a complex genetic architecture. In addition to the Tas1r3 gene, these differences depend on other genes likely involved in determining the taste and postingestive effects of amino acids. The identification of these genes may lead to the discovery of novel mechanisms that regulate amino acid taste and appetite. PMID:27422518

Genetic Interactions with Prenatal Social Environment: Effects on Academic and Behavioral Outcomes

ERIC Educational Resources Information Center

Conley, Dalton; Rauscher, Emily

2013-01-01

Numerous studies report gene-environment interactions, suggesting that specific alleles have different effects on social outcomes depending on environment. In all these studies, however, environmental conditions are potentially endogenous to unmeasured genetic characteristics. That is, it could be that the observed interaction effects actually…

Links of gut microbiota composition with alcohol dependence syndrome and alcoholic liver disease.

PubMed

Dubinkina, Veronika B; Tyakht, Alexander V; Odintsova, Vera Y; Yarygin, Konstantin S; Kovarsky, Boris A; Pavlenko, Alexander V; Ischenko, Dmitry S; Popenko, Anna S; Alexeev, Dmitry G; Taraskina, Anastasiya Y; Nasyrova, Regina F; Krupitsky, Evgeny M; Shalikiani, Nino V; Bakulin, Igor G; Shcherbakov, Petr L; Skorodumova, Lyubov O; Larin, Andrei K; Kostryukova, Elena S; Abdulkhakov, Rustam A; Abdulkhakov, Sayar R; Malanin, Sergey Y; Ismagilova, Ruzilya K; Grigoryeva, Tatiana V; Ilina, Elena N; Govorun, Vadim M

2017-10-17

Alcohol abuse has deleterious effects on human health by disrupting the functions of many organs and systems. Gut microbiota has been implicated in the pathogenesis of alcohol-related liver diseases, with its composition manifesting expressed dysbiosis in patients suffering from alcoholic dependence. Due to its inherent plasticity, gut microbiota is an important target for prevention and treatment of these diseases. Identification of the impact of alcohol abuse with associated psychiatric symptoms on the gut community structure is confounded by the liver dysfunction. In order to differentiate the effects of these two factors, we conducted a comparative "shotgun" metagenomic survey of 99 patients with the alcohol dependence syndrome represented by two cohorts-with and without liver cirrhosis. The taxonomic and functional composition of the gut microbiota was subjected to a multifactor analysis including comparison with the external control group. Alcoholic dependence and liver cirrhosis were associated with profound shifts in gut community structures and metabolic potential across the patients. The specific effects on species-level community composition were remarkably different between cohorts with and without liver cirrhosis. In both cases, the commensal microbiota was found to be depleted. Alcoholic dependence was inversely associated with the levels of butyrate-producing species from the Clostridiales order, while the cirrhosis-with multiple members of the Bacteroidales order. The opportunist pathogens linked to alcoholic dependence included pro-inflammatory Enterobacteriaceae, while the hallmarks of cirrhosis included an increase of oral microbes in the gut and more frequent occurrence of abnormal community structures. Interestingly, each of the two factors was associated with the expressed enrichment in many Bifidobacterium and Lactobacillus-but the exact set of the species was different between alcoholic dependence and liver cirrhosis. At the level of functional potential, the patients showed different patterns of increase in functions related to alcohol metabolism and virulence factors, as well as pathways related to inflammation. Multiple shifts in the community structure and metabolic potential suggest strong negative influence of alcohol dependence and associated liver dysfunction on gut microbiota. The identified differences in patterns of impact between these two factors are important for planning of personalized treatment and prevention of these pathologies via microbiota modulation. Particularly, the expansion of Bifidobacterium and Lactobacillus suggests that probiotic interventions for patients with alcohol-related disorders using representatives of the same taxa should be considered with caution. Taxonomic and functional analysis shows an increased propensity of the gut microbiota to synthesis of the toxic acetaldehyde, suggesting higher risk of colorectal cancer and other pathologies in alcoholics.

Support for context effects on segmentation and segments depends on the context.

PubMed

Heffner, Christopher C; Newman, Rochelle S; Idsardi, William J

2017-04-01

Listeners must adapt to differences in speech rate across talkers and situations. Speech rate adaptation effects are strong for adjacent syllables (i.e., proximal syllables). For studies that have assessed adaptation effects on speech rate information more than one syllable removed from a point of ambiguity in speech (i.e., distal syllables), the difference in strength between different types of ambiguity is stark. Studies of word segmentation have shown large shifts in perception as a result of distal rate manipulations, while studies of segmental perception have shown only weak, or even nonexistent, effects. However, no study has standardized methods and materials to study context effects for both types of ambiguity simultaneously. Here, a set of sentences was created that differed as minimally as possible except for whether the sentences were ambiguous to the voicing of a consonant or ambiguous to the location of a word boundary. The sentences were then rate-modified to slow down the distal context speech rate to various extents, dependent on three different definitions of distal context that were adapted from previous experiments, along with a manipulation of proximal context to assess whether proximal effects were comparable across ambiguity types. The results indicate that the definition of distal influenced the extent of distal rate effects strongly for both segments and segmentation. They also establish the presence of distal rate effects on word-final segments for the first time. These results were replicated, with some caveats regarding the perception of individual segments, in an Internet-based sample recruited from Mechanical Turk.

Raman spectroscopy detection of biomolecules in biocrusts from differing environmental conditions.

PubMed

Miralles, I; Jorge-Villar, S E; van Wesemael, B; Lázaro, R

2017-01-15

Lichens and cyanobacteria colonize inhospitable places covering a wide climate range due to their different survival strategies, such as the synthesis of protective biomolecules. The effect of ecological factors on the synthesis of biomolecules has not been widely analysed. This study aimed to assess the effects of four factors (species, microclimate, seasonality and hydration state) and their interactions on the biomolecule frequency detected by Raman Spectroscopy. We included cyanobacterial biocrusts, and the lichens Diploschistes diacapsis, Squamarina lentigera, and Lepraria isidiata; two contrasted microclimates (typical and marginal), two contrasted seasons (hot and dry vs cool and wet) and two hydration states (dry and wet). "Species" was the most influential factor in the identity and frequency of the main biomolecules. Microclimatic differences in the range of the local specific habitats only influenced the biomolecules in cyanobacteria. There was a quadruple interaction among the factors, the effects being different mainly depending on the species. At D. diacapsis, the production of their main biomolecules depended on microclimate, although it also depended on seasonality. Nevertheless, in L. isidiata and S. lentigera microclimatic differences did not significantly affect the production of biomolecules. In the lichen species, the microhabitats exposed to relatively larger incident radiation did not show significantly larger relative frequency of photoprotective biomolecules. No clear connection between higher production of oxalates and drier microhabitats was found, suggesting that the synthesis of oxalates is not related to water reserve strategy. The pros and cons of monitor biomolecules in biocrust by Raman spectrometry were also discussed. Copyright © 2016. Published by Elsevier B.V.

Stress indicator gene expression profiles, colony dynamics and tissue development of honey bees exposed to sub-lethal doses of imidacloprid in laboratory and field experiments.

PubMed

De Smet, Lina; Hatjina, Fani; Ioannidis, Pavlos; Hamamtzoglou, Anna; Schoonvaere, Karel; Francis, Frédéric; Meeus, Ivan; Smagghe, Guy; de Graaf, Dirk C

2017-01-01

In this study, different context-dependent effects of imidacloprid exposure on the honey bee response were studied. Honey bees were exposed to different concentrations of imidacloprid during a time period of 40 days. Next to these variables, a laboratory-field comparison was conducted. The influence of the chronic exposure on gene expression levels was determined using an in-house developed microarray targeting different immunity-related and detoxification genes to determine stress-related gene expression changes. Increased levels of the detoxification genes encoding, CYP9Q3 and CYT P450, were detected in imidacloprid-exposed honey bees. The different context-dependent effects of imidacloprid exposure on honey bees were confirmed physiologically by decreased hypopharyngeal gland sizes. Honey bees exposed to imidacloprid in laboratory cages showed a general immunosuppression and no detoxification mechanisms were triggered significantly, while honey bees in-field showed a resilient response with an immune stimulation at later time points. However, the treated colonies had a brood and population decline tendency after the first brood cycle in the field. In conclusion, this study highlighted the different context-dependent effects of imidacloprid exposure on the honey bee response. These findings warn for possible pitfalls concerning the generalization of results based on specific experiments with short exposure times. The increased levels of CYT P450 and CYP9Q3 combined with an immune response reaction can be used as markers for bees which are exposed to pesticides in the field.

Stress indicator gene expression profiles, colony dynamics and tissue development of honey bees exposed to sub-lethal doses of imidacloprid in laboratory and field experiments

PubMed Central

Ioannidis, Pavlos; Hamamtzoglou, Anna; Schoonvaere, Karel; Francis, Frédéric; Meeus, Ivan; Smagghe, Guy; de Graaf, Dirk C.

2017-01-01

In this study, different context-dependent effects of imidacloprid exposure on the honey bee response were studied. Honey bees were exposed to different concentrations of imidacloprid during a time period of 40 days. Next to these variables, a laboratory-field comparison was conducted. The influence of the chronic exposure on gene expression levels was determined using an in-house developed microarray targeting different immunity-related and detoxification genes to determine stress-related gene expression changes. Increased levels of the detoxification genes encoding, CYP9Q3 and CYT P450, were detected in imidacloprid-exposed honey bees. The different context-dependent effects of imidacloprid exposure on honey bees were confirmed physiologically by decreased hypopharyngeal gland sizes. Honey bees exposed to imidacloprid in laboratory cages showed a general immunosuppression and no detoxification mechanisms were triggered significantly, while honey bees in-field showed a resilient response with an immune stimulation at later time points. However, the treated colonies had a brood and population decline tendency after the first brood cycle in the field. In conclusion, this study highlighted the different context-dependent effects of imidacloprid exposure on the honey bee response. These findings warn for possible pitfalls concerning the generalization of results based on specific experiments with short exposure times. The increased levels of CYT P450 and CYP9Q3 combined with an immune response reaction can be used as markers for bees which are exposed to pesticides in the field. PMID:28182641

A redox-based mechanism for the contractile and relaxing effects of NO in the guinea-pig gall bladder

PubMed Central

Alcón, Soledad; Morales, Sara; Camello, Pedro J; Hemming, Jason M; Jennings, Lee; Mawe, Gary M; Pozo, María J

2001-01-01

The purpose of this study was to determine the effects of sodium nitroprusside (SNP), 2,2′-(hydroxynitrosohydrazino)bis-ethanamine (DETA/NO) and 3-morpholinosydnonimine (SIN-1), NO donors which yield different NO reactive species (NO+, NO. and peroxynitrite, respectively), as well as exogenous peroxynitrite, on gall bladder contractility. Under resting tone conditions, SNP induced a dose-dependent contraction with a maximal effect (10.3 ± 0.7 mN, s.e.m.) at 1 mm. Consistent with these findings, SNP caused a concentration-dependent depolarization of gall bladder smooth muscle. The excitatory effects of SNP were dependent on extracellular calcium entry through L-type Ca2+ channels. Furthermore, the contraction and depolarization were sensitive to tyrosine kinase blockade, and an associated increase in tyrosine phosphorylation was detected in Western blot studies. DETA/NO induced dose-dependent relaxing effects. These relaxations were sensitive to the guanylyl cyclase inhibitor 1H-[1,2,4]oxidiazolo[4,3-a]quinoxaline-1-one (ODQ, 2 μm) but they were not altered by treatment with the potassium channel blockers tetraethylammoniun (TEA, 5 mm) and 4-aminopyridine (4-AP, 5 mm). When tested in a reducing environment (created by 2.5 mm 1,4-dithiothreitol, DTT), SNP caused a relaxation of gall bladder muscle strips. Similarly, the SNP-induced contraction was converted to a relaxation, and associated hyperpolarization, when DTT was added during the steady state of an SNP-induced response. SIN-1 (0.1 mm), which has been shown to release peroxynitrite, induced relaxing effects that were enhanced by superoxide dismutase (SOD, 50 U ml−1). The relaxations induced by either SIN-1 alone or SIN-1 in the presence of SOD were strengthened by catalase (1000 U ml−1) and abolished by ODQ pretreatment. However, exogenous peroxynitrite induced a concentration-dependent contraction, which was dependent on activation of leukotriene (LT) metabolism and extracellular calcium. The peroxynitrite-induced contraction was abolished in the presence of the peroxynitrite scavenger melatonin. These results suggest that SIN-1 behaves as an NO. rather than a peroxynitrite source. We conclude that, depending on the redox state, NO has opposing effects on the motility of the gall bladder, being a relaxing agent when in NO. form and a contracting agent when in NO+ or peroxynitrite redox species form. Knowledge of the contrasting effects of the different redox forms of NO can clarify our understanding of the effects of NO donors on gall bladder and other smooth muscle cell types. PMID:11313447

Distinct effects of pollinator dependence and self-incompatibility on pollen limitation in South African biodiversity hotspots.

PubMed

Rodger, James G; Ellis, Allan G

2016-06-01

Global synthesis indicates that limitation of plant fecundity by pollen receipt (pollen limitation) is positively related to regional plant diversity and is higher for self-incompatible than self-compatible species. While self-incompatible species are always dependent on pollinating agents, self-compatible species may be pollinator-dependent or autofertile. This should cause variation in pollen limitation among self-compatible species, with lower pollen limitation in autofertile species because they do not depend on pollinators. We hypothesized that the intensity of pollen limitation in self-incompatible compared with pollinator-dependent self-compatible species should depend on whether pollen limitation is determined more by quantity than quality of pollen received. We compared pollen limitation between these three groups using a dataset of 70 biotically pollinated species from biodiverse regions of South Africa. Comparison with a global dataset indicated that pollen limitation in the South African biodiversity hotspots was generally comparable to other regions, despite expectations of higher pollen limitation based on the global plant diversity-pollen limitation relationship. Pollen limitation was lowest for autofertile species, as expected. It was also higher for pollinator-dependent self-compatible species than self-incompatible species, consistent with increased pollen-quality limitation in the former group due to negative consequences of pollinator-mediated self-pollination. However, there was a higher frequency of plants with zygomorphic flowers, which were also more pollen-limited, among pollinator-dependent self-compatible species. Thus, we could not attribute this difference in pollen limitation exclusively to a difference in pollen quality. Nevertheless, our results indicate that comparative studies should control for both pollinator dependence and self-incompatiblity when evaluating effects of other factors on pollen limitation. © 2016 The Author(s).

Five-Factor Model Personality Profiles: The Differences between Alcohol and Opiate Addiction among Females.

PubMed

Raketic, Diana; Barisic, Jasmina V; Svetozarevic, Snezana M; Gazibara, Tatjana; Tepavcevic, Darija Kisic; Milovanovic, Srdjan D

2017-03-01

The prevalence of female alcohol and substance abusers has markedly increased. The main objective of this research was to explore personality profiles among females who had alcohol and opiate dependence. The aim of the study is to analyse if there is differences in personality profiles of females addicted to alcohol and opiates. We hypothesized that there might be significant differences in personality profiles among subgroups of women who present with alcohol and opiate use disorders. Of 157 consecutive women with diagnosis of alcohol/opiate addiction, 62 fulfilled following inclusion criteria: age 19-45 years, abstinence from alcohol and opiates for at least 10 days prior to enrollment. Alcohol-dependent group consisted of 30 females, while opiate-dependent group consisted of 32 females. The control group involved 30 age-matched randomly chosen healthy women. The data were collected using the Revised NEO Personality Inventory (NEO-PI-R). The multiple stepwise discriminant analysis was used to determine relations between personality traits and the probability of belonging to one of the study groups. Significant differences in the NEO-PI-R scores were observed between groups for all main personality traits except for Openness to Experience. Compared with controls, substance-dependent women scored significantly higher on Neuroticism and lower on Conscientiousness. Opiate-dependent females scored the highest on Neuroticism and on Extraversion and lowest on Agreeableness and on Conscientiousness. Alcohol-dependent females scored higher on Conscientiousness and lower on Neuroticism compared to opiate-dependent women. The results of our study confirmed significant characteristics in personality profiles among females with alcohol and opiate dependence, as well as the difference between these two groups of substance abusers and their healthy controls. The distinct personality characteristics among different groups of substance addicted women should be taken into account when creating the most effective program of prevention and therapeutic approaches in this specific cohort.

Enhanced Sensitivity to Attenuation of Conditioned Reinstatement by the mGluR2/3 Agonist LY379268 and Increased Functional Activity of mGluR2/3 in Rats with a History of Ethanol Dependence

PubMed Central

Kufahl, Peter R; Martin-Fardon, Rémi; Weiss, Friedbert

2011-01-01

Recent findings implicate group II metabotropic glutamate receptors (mGluR2/3) in the reinforcing and dependence-inducing actions of ethanol and identify these receptors as treatment targets for alcoholism. Here, we investigated the effects of mGLuR2/3 activation on conditioned reinstatement in rats with different ethanol-dependence histories and examined dependence-associated changes in the functional activity of mGluR2/3. Following ethanol self-administration training and conditioning procedures, rats were made ethanol dependent, using ethanol vapor inhalation, under three conditions: a single intoxication and withdrawal episode (SW), repeated cycles of intoxication and withdrawal (RW), or no intoxication (CTRL). At 1 week after removal from ethanol vapor, self-administration resumed until stable baseline performance was reached, followed by extinction of operant responding and reinstatement tests. Post-withdrawal self-administration was increased in the RW group, but all groups showed conditioned reinstatement. The mGluR2/3 agonist LY379268 dose -dependently reduced reinstatement in all groups, but was more effective at low doses in the SW and RW groups. The highest dose of LY379268 tested reduced spontaneous locomotor activity and operant responding maintained by a non-drug reinforcer, without differences among groups. The heightened sensitivity to the effects of LY379268 in rats with an ethanol-dependence history was therefore specific to behavior motivated by ethanol-related stimuli. Both the SW and RW groups showed elevated [35S]GTPγS binding in the central nucleus of the amygdala (CeA) and bed nucleus of stria terminalis (BNST), relative to the CTRL group. The findings implicate changes in mGluR2/3 functional activity as a factor in ethanol dependence and support treatment target potential of mGlu2/3 receptors for craving and relapse prevention. PMID:21881571

In Vitro Activity of Glucosinolates and Their Degradation Products against Brassica-Pathogenic Bacteria and Fungi

PubMed Central

Sotelo, T.; Lema, M.; Soengas, P.; Cartea, M. E.

2014-01-01

Glucosinolates (GSLs) are secondary metabolites found in Brassica vegetables that confer on them resistance against pests and diseases. Both GSLs and glucosinolate hydrolysis products (GHPs) have shown positive effects in reducing soil pathogens. Information about their in vitro biocide effects is scarce, but previous studies have shown sinigrin GSLs and their associated allyl isothiocyanate (AITC) to be soil biocides. The objective of this work was to evaluate the biocide effects of 17 GSLs and GHPs and of leaf methanolic extracts of different GSL-enriched Brassica crops on suppressing in vitro growth of two bacterial (Xanthomonas campestris pv. campestris and Pseudomonas syringae pv. maculicola) and two fungal (Alternaria brassicae and Sclerotinia scletoriorum) Brassica pathogens. GSLs, GHPs, and methanolic leaf extracts inhibited the development of the pathogens tested compared to the control, and the effect was dose dependent. Furthermore, the biocide effects of the different compounds studied were dependent on the species and race of the pathogen. These results indicate that GSLs and their GHPs, as well as extracts of different Brassica species, have potential to inhibit pathogen growth and offer new opportunities to study the use of Brassica crops in biofumigation for the control of multiple diseases. PMID:25362058

Edge-defect induced spin-dependent Seebeck effect and spin figure of merit in graphene nanoribbons.

PubMed

Liu, Qing-Bo; Wu, Dan-Dan; Fu, Hua-Hua

2017-10-11

By using the first-principle calculations combined with the non-equilibrium Green's function approach, we have studied spin caloritronic properties of graphene nanoribbons (GNRs) with different edge defects. The theoretical results show that the edge-defected GNRs with sawtooth shapes can exhibit spin-dependent currents with opposite flowing directions by applying temperature gradients, indicating the occurrence of the spin-dependent Seebeck effect (SDSE). The edge defects bring about two opposite effects on the thermal spin currents: the enhancement of the symmetry of thermal spin-dependent currents, which contributes to the realization of pure thermal spin currents, and the decreasing of the spin thermoelectric conversion efficiency of the devices. It is fortunate that applying a gate voltage is an efficient route to optimize these two opposite spin thermoelectric properties towards realistic device applications. Moreover, due to the existence of spin-splitting band gaps, the edge-defected GNRs can be designed as spin-dependent Seebeck diodes and rectifiers, indicating that the edge-defected GNRs are potential candidates for room-temperature spin caloritronic devices.

Modelling & Simulation Support to the Effects Based Approach to Operations - Observations from Using GAMMA in MNE 4

DTIC Science & Technology

2006-09-01

The aim of the two parts of the experiment was identical: To explore concepts and supporting tools for Effects Based Approach to Operations (EBAO...feedback on the PMESII factors over time and the degree of achievement of the Operational Endstate. Modelling & Simulation Support to the Effects ...specific situation depends also on his interests. GAMMA provides two different methods: 1. The importance for different PMESII factors (ie potential

Energy-dependent effects of resveratrol in Saccharomyces cerevisiae.

PubMed

Madrigal-Perez, Luis Alberto; Canizal-Garcia, Melina; González-Hernández, Juan Carlos; Reynoso-Camacho, Rosalia; Nava, Gerardo M; Ramos-Gomez, Minerva

2016-06-01

The metabolic effects induced by resveratrol have been associated mainly with the consumption of high-calorie diets; however, its effects with standard or low-calorie diets remain unclear. To better understand the interactions between resveratrol and cellular energy levels, we used Saccharomyces cerevisiae as a model. Herein it is shown that resveratrol: (a) decreased cell viability in an energy-dependent manner; (b) lessening of cell viability occurred specifically when cells were under cellular respiration; and (c) inhibition of oxygen consumption in state 4 occurred at low and standard energy levels, whereas at high energy levels oxygen consumption was promoted. These findings indicate that the effects of resveratrol are dependent on the cellular energy status and linked to metabolic respiration. Importantly, our study also revealed that S. cerevisiae is a suitable and useful model to elucidate the molecular targets of resveratrol under different nutritional statuses. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Speech variability effects on recognition accuracy associated with concurrent task performance by pilots

NASA Technical Reports Server (NTRS)

Simpson, C. A.

1985-01-01

In the present study of the responses of pairs of pilots to aircraft warning classification tasks using an isolated word, speaker-dependent speech recognition system, the induced stress was manipulated by means of different scoring procedures for the classification task and by the inclusion of a competitive manual control task. Both speech patterns and recognition accuracy were analyzed, and recognition errors were recorded by type for an isolated word speaker-dependent system and by an offline technique for a connected word speaker-dependent system. While errors increased with task loading for the isolated word system, there was no such effect for task loading in the case of the connected word system.

Effect of Different Stressors on Voluntary Ethanol Intake in Ethanol-Dependent and Nondependent C57BL/6J Mice

PubMed Central

Lopez, Marcelo F.; Anderson, Rachel I.; Becker, Howard C.

2016-01-01

Several animal models have evaluated the effect of stress on voluntary ethanol intake with mixed results. The experiments reported here examined the effects of different stressors on voluntary ethanol consumption in dependent and nondependent adult male C57BL/6J mice. In Experiment 1, restraint, forced swim, and social defeat stress procedures all tended to reduce ethanol intake in nondependent mice regardless of whether the stress experience occurred 1 h or 4 h prior to ethanol access. The reduction in ethanol consumption was most robust following restraint stress. Experiment 2 examined the effects of forced swim stress and social defeat stress on drinking in a dependence model that involved repeated cycles of chronic intermittent ethanol (CIE) exposure. Repeated exposure to forced swim stress prior to intervening test drinking periods that followed repeated cycles of CIE exposure further increased ethanol consumption in CIE-exposed mice while not altering intake in nondependent mice. In contrast, repeated exposure to the social defeat stressor in a similar manner reduced ethanol consumption in CIE-exposed mice while not altering drinking in nondependent mice. Results from Experiment 3 confirmed this selective effect of forced swim stress increasing ethanol consumption in mice with a history of CIE exposure, and also demonstrated that enhanced drinking is only observed when the forced swim stressor is administered during each test drinking week, but not if it is applied only during the final test week. Collectively, these studies point to a unique interaction between repeated stress experience and CIE exposure, and also suggest that such an effect depends on the nature of the stressor. Future studies will need to further explore the generalizability of these results, as well as mechanisms underlying the ability of forced swim stress to selectively further enhance ethanol consumption in dependent (CIE-exposed) mice but not alter intake in nondependent animals. PMID:26992696

Effect of different stressors on voluntary ethanol intake in ethanol-dependent and nondependent C57BL/6J mice.

PubMed

Lopez, Marcelo F; Anderson, Rachel I; Becker, Howard C

2016-03-01

Several animal models have evaluated the effect of stress on voluntary ethanol intake with mixed results. The experiments reported here examined the effects of different stressors on voluntary ethanol consumption in dependent and nondependent adult male C57BL/6J mice. In Experiment 1, restraint, forced swim, and social defeat stress procedures all tended to reduce ethanol intake in nondependent mice regardless of whether the stress experience occurred 1 h or 4 h prior to ethanol access. The reduction in ethanol consumption was most robust following restraint stress. Experiment 2 examined the effects of forced swim stress and social defeat stress on drinking in a dependence model that involved repeated cycles of chronic intermittent ethanol (CIE) exposure. Repeated exposure to forced swim stress prior to intervening test drinking periods that followed repeated cycles of CIE exposure further increased ethanol consumption in CIE-exposed mice while not altering intake in nondependent mice. In contrast, repeated exposure to the social defeat stressor in a similar manner reduced ethanol consumption in CIE-exposed mice while not altering drinking in nondependent mice. Results from Experiment 3 confirmed this selective effect of forced swim stress increasing ethanol consumption in mice with a history of CIE exposure, and also demonstrated that enhanced drinking is only observed when the forced swim stressor is administered during each test drinking week, but not if it is applied only during the final test week. Collectively, these studies point to a unique interaction between repeated stress experience and CIE exposure, and also suggest that such an effect depends on the nature of the stressor. Future studies will need to further explore the generalizability of these results, as well as mechanisms underlying the ability of forced swim stress to selectively further enhance ethanol consumption in dependent (CIE-exposed) mice but not alter intake in nondependent animals. Copyright © 2016 Elsevier Inc. All rights reserved.

Experimental Investigation of Hysteretic Dynamic Capillarity Effect in Unsaturated Flow

PubMed Central

Zhuang, Luwen; Qin, Chao‐Zhong; de Waal, Arjen

2017-01-01

Abstract The difference between average pressures of two immiscible fluids is commonly assumed to be the same as macroscopic capillary pressure, which is considered to be a function of saturation only. However, under transient conditions, a dependence of this pressure difference on the time rate of saturation change has been observed by many researchers. This is commonly referred to as dynamic capillarity effect. As a first‐order approximation, the dynamic term is assumed to be linearly dependent on the time rate of change of saturation, through a material coefficient denoted by τ. In this study, a series of laboratory experiments were carried out to quantify the dynamic capillarity effect in an unsaturated sandy soil. Primary, main, and scanning drainage experiments, under both static and dynamic conditions, were performed on a sandy soil in a small cell. The value of the dynamic capillarity coefficient τ was calculated from the air‐water pressure differences and average saturation values during static and dynamic drainage experiments. We found a dependence of τ on saturation, which showed a similar trend for all drainage conditions. However, at any given saturation, the value of τ for primary drainage was larger than the value for main drainage and that was in turn larger than the value for scanning drainage. Each data set was fit a simple log‐linear equation, with different values of fitting parameters. This nonuniqueness of the relationship between τ and saturation and possible causes is discussed. PMID:29398729

Experimental Investigation of Hysteretic Dynamic Capillarity Effect in Unsaturated Flow

NASA Astrophysics Data System (ADS)

Zhuang, Luwen; Hassanizadeh, S. Majid; Qin, Chao-Zhong; de Waal, Arjen

2017-11-01

The difference between average pressures of two immiscible fluids is commonly assumed to be the same as macroscopic capillary pressure, which is considered to be a function of saturation only. However, under transient conditions, a dependence of this pressure difference on the time rate of saturation change has been observed by many researchers. This is commonly referred to as dynamic capillarity effect. As a first-order approximation, the dynamic term is assumed to be linearly dependent on the time rate of change of saturation, through a material coefficient denoted by τ. In this study, a series of laboratory experiments were carried out to quantify the dynamic capillarity effect in an unsaturated sandy soil. Primary, main, and scanning drainage experiments, under both static and dynamic conditions, were performed on a sandy soil in a small cell. The value of the dynamic capillarity coefficient τ was calculated from the air-water pressure differences and average saturation values during static and dynamic drainage experiments. We found a dependence of τ on saturation, which showed a similar trend for all drainage conditions. However, at any given saturation, the value of τ for primary drainage was larger than the value for main drainage and that was in turn larger than the value for scanning drainage. Each data set was fit a simple log-linear equation, with different values of fitting parameters. This nonuniqueness of the relationship between τ and saturation and possible causes is discussed.

Parameter Optimization Analysis of Prolonged Analgesia Effect of tDCS on Neuropathic Pain Rats

PubMed Central

Wen, Hui-Zhong; Gao, Shi-Hao; Zhao, Yan-Dong; He, Wen-Juan; Tian, Xue-Long; Ruan, Huai-Zhen

2017-01-01

Background: Transcranial direct current stimulation (tDCS) is widely used to treat human nerve disorders and neuropathic pain by modulating the excitability of cortex. The effectiveness of tDCS is influenced by its stimulation parameters, but there have been no systematic studies to help guide the selection of different parameters. Objective: This study aims to assess the effects of tDCS of primary motor cortex (M1) on chronic neuropathic pain in rats and to test for the optimal parameter combinations for analgesia. Methods: Using the chronic neuropathic pain models of chronic constriction injury (CCI), we measured pain thresholds before and after anodal-tDCS (A-tDCS) using different parameter conditions, including stimulation intensity, stimulation time, intervention time and electrode located (ipsilateral or contralateral M1 of the ligated paw on male/female CCI models). Results: Following the application of A-tDCS over M1, we observed that the antinociceptive effects were depended on different parameters. First, we found that repetitive A-tDCS had a longer analgesic effect than single stimulus, and both ipsilateral-tDCS (ip-tDCS) and contralateral-tDCS (con-tDCS) produce a long-lasting analgesic effect on neuropathic pain. Second, the antinociceptive effects were intensity-dependent and time-dependent, high intensities worked better than low intensities and long stimulus durations worked better than short stimulus durations. Third, timing of the intervention after injury affected the stimulation outcome, early use of tDCS was an effective method to prevent the development of pain, and more frequent intervention induced more analgesia in CCI rats, finally, similar antinociceptive effects of con- and ip-tDCS were observed in both sexes of CCI rats. Conclusion: Optimized protocols of tDCS for treating antinociceptive effects were developed. These findings should be taken into consideration when using tDCS to produce analgesic effects in clinical applications. PMID:28659772

Spatial variation and density-dependent dispersal in competitive coexistence.

PubMed Central

Amarasekare, Priyanga

2004-01-01

It is well known that dispersal from localities favourable to a species' growth and reproduction (sources) can prevent competitive exclusion in unfavourable localities (sinks). What is perhaps less well known is that too much emigration can undermine the viability of sources and cause regional competitive exclusion. Here, I investigate two biological mechanisms that reduce the cost of dispersal to source communities. The first involves increasing the spatial variation in the strength of competition such that sources can withstand high rates of emigration; the second involves reducing emigration from sources via density-dependent dispersal. I compare how different forms of spatial variation and modes of dispersal influence source viability, and hence source-sink coexistence, under dominance and pre-emptive competition. A key finding is that, while spatial variation substantially reduces dispersal costs under both types of competition, density-dependent dispersal does so only under dominance competition. For instance, when spatial variation in the strength of competition is high, coexistence is possible (regardless of the type of competition) even when sources experience high emigration rates; when spatial variation is low, coexistence is restricted even under low emigration rates. Under dominance competition, density-dependent dispersal has a strong effect on coexistence. For instance, when the emigration rate increases with density at an accelerating rate (Type III density-dependent dispersal), coexistence is possible even when spatial variation is quite low; when the emigration rate increases with density at a decelerating rate (Type II density-dependent dispersal), coexistence is restricted even when spatial variation is quite high. Under pre-emptive competition, density-dependent dispersal has only a marginal effect on coexistence. Thus, the diversity-reducing effects of high dispersal rates persist under pre-emptive competition even when dispersal is density dependent, but can be significantly mitigated under dominance competition if density-dependent dispersal is Type III rather than Type II. These results lead to testable predictions about source-sink coexistence under different regimes of competition, spatial variation and dispersal. They identify situations in which density-independent dispersal provides a reasonable approximation to species' dispersal patterns, and those under which consideration of density-dependent dispersal is crucial to predicting long-term coexistence. PMID:15306322

The Effect of Motivational Interviewing on Craving and Dependence on Hookah in Suburban Pregnant Women in South East of Iran.

PubMed

Mojahed, Kheirolnesa; Navidian, Ali

2018-05-30

Hookah smoking during pregnancy is a health concern which requires effective interventions. Thus, the authors have aimed to evaluate the effect of motivational interviewing on craving and dependence on hookah in pregnant women (n = 140) addicted to hookah who reside in the outskirts of Zahedan, a city in southeast of Iran. The subjects were selected using the convenience sampling and randomly divided into either the control or intervention group. The intervention group received five motivational interviewing group sessions about hookah smoking withdrawal, whereas the control group was given the conventional recommendations for quitting hookah. Data were collected after eight weeks during the post intervention period using Hookah Craving Test and Hookah Addiction Severity Index. Next, they were analyzed using independent t-test, paired t-test, and analysis of covariance (ANCOVA). After the motivational interviewing intervention, the independent t-test indicated a significant difference between the intervention and control groups in terms of the mean score of hookah craving (P = 0.0001). Moreover, ANCOVA, with control of the effect of pretest and duration of hookah addiction, demonstrated a significant difference between the two groups regarding the mean score of hookah dependence after the intervention (P = 0.0001). Motivational interviewing had a significant positive impact on decreased hookah craving and dependence (two indices of withdrawal). Therefore, healthcare providers are recommended to incorporate motivational interviewing-based education into prenatal care programs to promote the chance of hookah smoking withdrawal.

Loading mode dependent effective properties of octet-truss lattice structures using 3D-printing

NASA Astrophysics Data System (ADS)

Challapalli, Adithya

Cellular materials, often called lattice materials, are increasingly receiving attention for their ultralight structures with high specific strength, excellent impact absorption, acoustic insulation, heat dissipation media and compact heat exchangers. In alignment with emerging additive manufacturing (AM) technology, realization of the structural applications of the lattice materials appears to be becoming faster. Considering the direction dependent material properties of the products with AM, by directionally dependent printing resolution, effective moduli of lattice structures appear to be directionally dependent. In this paper, a constitutive model of a lattice structure, which is an octet-truss with a base material having an orthotropic material property considering AM is developed. In a case study, polyjet based 3D printing material having an orthotropic property with a 9% difference in the principal direction provides difference in the axial and shear moduli in the octet-truss by 2.3 and 4.6%. Experimental validation for the effective properties of a 3D printed octet-truss is done for uniaxial tension and compression test. The theoretical value based on the micro-buckling of truss member are used to estimate the failure strength. Modulus value appears a little overestimate compared with the experiment. Finite element (FE) simulations for uniaxial compression and tension of octettruss lattice materials are conducted. New effective properties for the octet-truss lattice structure are developed considering the observed behavior of the octet-truss structure under macroscopic compression and tension trough simulations.

Consumer effects on the vital rates of their resource can determine the outcome of competition between consumers.

PubMed

Lee, Charlotte T; Miller, Tom E X; Inouye, Brian D

2011-10-01

Current competition theory does not adequately address the fact that competitors may affect the survival, growth, and reproductive rates of their resources. Ecologically important interactions in which consumers affect resource vital rates range from parasitism and herbivory to mutualism. We present a general model of competition that explicitly includes consumer-dependent resource vital rates. We build on the classic MacArthur model of competition for multiple resources, allowing direct comparison with expectations from established concepts of resource-use overlap. Consumers share a stage-structured resource population but may use the different stages to different extents, as they do the different independent resources in the classic model. Here, however, the stages are dynamically linked via consumer-dependent vital rates. We show that consumers' effects on resource vital rates result in two important departures from classic results. First, consumers can coexist despite identical use of resource stages, provided each competitor shifts the resource stage distribution toward stages that benefit other species. Second, consumers specializing on different resource stages can compete strongly, possibly resulting in competitive exclusion despite a lack of resource stage-use overlap. Our model framework demonstrates the critical role that consumer-dependent resource vital rates can play in competitive dynamics in a wide range of biological systems.

In-medium effects via nuclear stopping in asymmetric colliding nuclei

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaur, Mandeep

2016-05-06

The nuclear stopping is studied using isospin-dependent quantum molecular dynamics (IQMD) model in asymmetric colliding nuclei by varying mass asymmetry. The calculations have been done at incident energies varying between 50 and 400 MeV/nucleon for different impact parameters. We investigate the relative role of constant scaled and density-dependent scaled cross-sections. Our study reveals that nuclear stopping depends on the mass asymmetry, incident energy and impact parameter, however, it is independent of the way of scaling the cross-section.

The effect of impurity on temperature variations in the refractive indices and thickness of TGS crystals

NASA Astrophysics Data System (ADS)

Stadnyk, V. Yo.; Andriyevsky, B. V.; Gaba, V. M.; Kogut, Z. A.

2016-06-01

Temperature dependences of optical path difference δΔi and the relative changes in thickness δ l i/ l of TGS crystals doped with L-valine are studied. Temperature dependences of the relative changes in refractive indices δ n i/( n-1) are calculated. The anisotropy coefficients of refractive indices An-1(T) and linear expansion Aα(T) are calculated, and a characteristic minimum of these dependences is found near the phase transition temperature.

Effects of Assuming Independent Component Failure Times, if They Actually Dependent, in a Series System.

DTIC Science & Technology

1984-10-26

test for independence; ons i ser, -, of the poduct life estimator; dependent risks; 119 ASRACT Coniinue on ’wme-se f nereiary-~and iaen r~f> by Worst...the failure times associated with different failure - modes when we really should use a bivariate (or multivariate) distribution, then what is the...dependencies may be present, then what is the magnitude of the estimation error? S The third specific aim will attempt to obtain bounds on the

Statistical test for ΔρDCCA cross-correlation coefficient

NASA Astrophysics Data System (ADS)

Guedes, E. F.; Brito, A. A.; Oliveira Filho, F. M.; Fernandez, B. F.; de Castro, A. P. N.; da Silva Filho, A. M.; Zebende, G. F.

2018-07-01

In this paper we propose a new statistical test for ΔρDCCA, Detrended Cross-Correlation Coefficient Difference, a tool to measure contagion/interdependence effect in time series of size N at different time scale n. For this proposition we analyzed simulated and real time series. The results showed that the statistical significance of ΔρDCCA depends on the size N and the time scale n, and we can define a critical value for this dependency in 90%, 95%, and 99% of confidence level, as will be shown in this paper.

Detailed validation of the bidirectional effect in various Case 1 waters for application to Ocean Color imagery

NASA Astrophysics Data System (ADS)

Voss, K. J.; Morel, A.; Antoine, D.

2007-06-01

The radiance viewed from the ocean depends on the illumination and viewing geometry along with the water properties and this variation is called the bidirectional effect, or BRDF of the water. This BRDF depends on the inherent optical properties of the water, including the volume scattering function, and is important when comparing data from different satellite sensors. The current model by Morel et al. (2002) depends on modeled water parameters, thus must be carefully validated. In this paper we combined upwelling radiance distribution data from several cruises, in varied water types and with a wide range of solar zenith angles. We found that the average error of the model, when compared to the data was less than 1%, while the RMS difference between the model and data was on the order of 0.02-0.03. This is well within the statistical noise of the data, which was on the order of 0.04-0.05, due to environmental noise sources such as wave focusing.

Changing crops in response to climate: virtual Nang Rong, Thailand in an agent based simulation

PubMed Central

Malanson, George P.; Verdery, Ashton M.; Walsh, Stephen J.; Sawangdee, Yothin; Heumann, Benjamin W.; McDaniel, Philip M.; Frizzelle, Brian G.; Williams, Nathalie E.; Yao, Xiaozheng; Entwisle, Barbara; Rindfuss, Ronald R.

2014-01-01

The effects of extended climatic variability on agricultural land use were explored for the type of system found in villages of northeastern Thailand. An agent based model developed for the Nang Rong district was used to simulate land allotted to jasmine rice, heavy rice, cassava, and sugar cane. The land use choices in the model depended on likely economic outcomes, but included elements of bounded rationality in dependence on household demography. The socioeconomic dynamics are endogenous in the system, and climate changes were added as exogenous drivers. Villages changed their agricultural effort in many different ways. Most villages reduced the amount of land under cultivation, primarily with reduction in jasmine rice, but others did not. The variation in responses to climate change indicates potential sensitivity to initial conditions and path dependence for this type of system. The differences between our virtual villages and the real villages of the region indicate effects of bounded rationality and limits on model applications. PMID:25061240

Effect of Loading Rate and Surface Conditions on Flexural Strength of Borosilicate Glass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nie, X; Chen, Wayne; Wereszczak, Andrew A

2009-01-01

This study evaluates the loading rate and surface condition dependence of the flexural strength of a borosilicate glass. The glass specimens are subjected to three different surface treatments before four-point bending tests to study the effect of surface flaws. Quasistatic (Material Test System 810) and dynamic (Kolsky bar) experiments are performed at loading rates ranging from 0.7 to 4 x 10{sup 6} MPa/s. The results show that the flexural strength of the borosilicate glass has a strong dependence on the loading rate. A chemically etched surface produces an enhanced flexural strength by about an order of magnitude. Scanning electron microscopymore » images on fracture surfaces indicate that the failure is governed by different types of flaws under different surface treatment conditions. Edge failure is also identified for samples possessing high flexural strength.« less

Effect of inductive and capacitive coupling on the current–voltage characteristic and electromagnetic radiation from a system of Josephson junctions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rahmonov, I. R., E-mail: rahmonov@theor.jinr.ru, E-mail: ilhom-tj@inbox.ru; Shukrinov, Yu. M.; Atanasova, P. Kh.

We have studied the current–voltage characteristic of a system of long Josephson junctions taking into account the inductive and capacitive coupling. The dependence of the average time derivative of the phase difference on the bias current and spatiotemporal dependences of the phase difference and magnetic field in each junction are considered. The possibility of branching of the current–voltage characteristic in the region of zero field step, which is associated with different numbers of fluxons in individual Josephson junctions, is demonstrated. The current–voltage characteristic of the system of Josephson junctions is compared with the case of a single junction, and itmore » is shown that the observed branching is due to coupling between the junctions. The intensity of electromagnetic radiation associated with motion of fluxons is calculated, and the effect of coupling between junctions on the radiation power is analyzed.« less

Effects of Moist Convection on Hurricane Predictability

NASA Technical Reports Server (NTRS)

Zhang, Fuqing; Sippel, Jason A.

2008-01-01

This study exemplifies inherent uncertainties in deterministic prediction of hurricane formation and intensity. Such uncertainties could ultimately limit the predictability of hurricanes at all time scales. In particular, this study highlights the predictability limit due to the effects on moist convection of initial-condition errors with amplitudes far smaller than those of any observation or analysis system. Not only can small and arguably unobservable differences in the initial conditions result in different routes to tropical cyclogenesis, but they can also determine whether or not a tropical disturbance will significantly develop. The details of how the initial vortex is built can depend on chaotic interactions of mesoscale features, such as cold pools from moist convection, whose timing and placement may significantly vary with minute initial differences. Inherent uncertainties in hurricane forecasts illustrate the need for developing advanced ensemble prediction systems to provide event-dependent probabilistic forecasts and risk assessment.

Influence of hyaluronic acid on bacterial and fungal species, including clinically relevant opportunistic pathogens.

PubMed

Ardizzoni, Andrea; Neglia, Rachele G; Baschieri, Maria C; Cermelli, Claudio; Caratozzolo, Manuela; Righi, Elena; Palmieri, Beniamino; Blasi, Elisabetta

2011-10-01

Hyaluronic acid (HA) has several clinical applications (aesthetic surgery, dermatology, orthopaedics and ophtalmology). Following recent evidence, suggesting antimicrobial and antiviral properties for HA, we investigated its effects on 15 ATCC strains, representative of clinically relevant bacterial and fungal species. The in vitro system employed allowed to assess optical density of broth cultures as a measure of microbial load in a time-dependent manner. The results showed that different microbial species and, sometimes, different strains belonging to the same species, are differently affected by HA. In particular, staphylococci, enterococci, Streptococcus mutans, two Escherichia coli strains, Pseudomonas aeruginosa, Candida glabrata and C. parapsilosis displayed a HA dose-dependent growth inhibition; no HA effects were detected in E. coli ATCC 13768 and C. albicans; S. sanguinis was favoured by the highest HA dose. Therefore, the influence of HA on bacteria and fungi warrants further studies aimed at better establishing its relevance in clinical applications.

Wavelength dependence of biological damage induced by UV radiation on bacteria.

PubMed

Santos, Ana L; Oliveira, Vanessa; Baptista, Inês; Henriques, Isabel; Gomes, Newton C M; Almeida, Adelaide; Correia, António; Cunha, Ângela

2013-01-01

The biological effects of UV radiation of different wavelengths (UVA, UVB and UVC) were assessed in nine bacterial isolates displaying different UV sensitivities. Biological effects (survival and activity) and molecular markers of oxidative stress [DNA strand breakage (DSB), generation of reactive oxygen species (ROS), oxidative damage to proteins and lipids, and the activity of antioxidant enzymes catalase and superoxide dismutase] were quantified and statistically analyzed in order to identify the major determinants of cell inactivation under the different spectral regions. Survival and activity followed a clear wavelength dependence, being highest under UVA and lowest under UVC. The generation of ROS, as well as protein and lipid oxidation, followed the same pattern. DNA damage (DSB) showed the inverse trend. Multiple stepwise regression analysis revealed that survival under UVA, UVB and UVC wavelengths was best explained by DSB, oxidative damage to lipids, and intracellular ROS levels, respectively.

Cannabis, Cigarettes, and Their Co-Occurring Use: Disentangling Differences in Gray Matter Volume

PubMed Central

Jagannathan, Kanchana; Hager, Nathan; Childress, Anna Rose; Rao, Hengyi; Franklin, Teresa R.

2015-01-01

Background: Structural magnetic resonance imaging techniques are powerful tools for examining the effects of drug use on the brain. The nicotine and cannabis literature has demonstrated differences between nicotine cigarette smokers and cannabis users compared to controls in brain structure; however, less is known about the effects of co-occurring cannabis and tobacco use. Methods: We used voxel-based morphometry to examine gray matter volume differences between four groups: (1) cannabis-dependent individuals who do not smoke tobacco (Cs); (2) cannabis-dependent individuals who smoke tobacco (CTs); (3) cannabis-naïve, nicotine-dependent individuals who smoke tobacco (Ts); and (4) healthy controls (HCs). We also explored associations between gray matter volume and measures of cannabis and tobacco use. Results: A significant group effect was observed in the left putamen, thalamus, right precentral gyrus, and left cerebellum. Compared to HCs, the Cs, CTs, and Ts exhibited larger gray matter volumes in the left putamen. Cs also had larger gray matter volume than HCs in the right precentral gyrus. Cs and CTs exhibited smaller gray matter volume than HCs in the thalamus, and CTs and Ts had smaller left cerebellar gray matter volume than HCs. Conclusions: This study extends previous research that independently examined the effects of cannabis or tobacco use on brain structure by including an examination of co-occurring cannabis and tobacco use, and provides evidence that cannabis and tobacco exposure are associated with alterations in brain regions associated with addiction. PMID:26045474

Improvement of attention with amphetamine in low- and high-performing rats.

PubMed

Turner, Karly M; Burne, Thomas H J

2016-09-01

Attentional deficits occur in a range of neuropsychiatric disorders, such as schizophrenia and attention deficit hyperactivity disorder. Psychostimulants are one of the main treatments for attentional deficits, yet there are limited reports of procognitive effects of amphetamine in preclinical studies. Therefore, task development may be needed to improve predictive validity when measuring attention in rodents. This study aimed to use a modified signal detection task (SDT) to determine if and at what doses amphetamine could improve attention in rats. Sprague-Dawley rats were trained on the SDT prior to amphetamine challenge (0.1, 0.25, 0.75 and 1.25 mg/kg). This dose range was predicted to enhance and disrupt cognition with the effect differing between individuals depending on baseline performance. Acute low dose amphetamine (0.1 and 0.25 mg/kg) improved accuracy, while the highest dose (1.25 mg/kg) significantly disrupted performance. The effects differed for low- and high-performing groups across these doses. The effect of amphetamine on accuracy was found to significantly correlate with baseline performance in rats. This study demonstrates that improvement in attentional performance with systemic amphetamine is dependent on baseline accuracy in rats. Indicative of the inverted U-shaped relationship between dopamine and cognition, there was a baseline-dependent shift in performance with increasing doses of amphetamine. The SDT may be a useful tool for investigating individual differences in attention and response to psychostimulants in rodents.

The dissimilar effect of diacylglycerols on Ca(2+)-induced phosphatidylserine vesicle fusion.

PubMed Central

Sánchez-Migallón, M P; Aranda, F J; Gómez-Fernández, J C

1995-01-01

We have studied the effect of physiological concentrations of different diacylglycerols on Ca(2+)-induced fusion between phosphatidylserine vesicles. We monitored vesicle fusion as mixing of membrane lipids under conditions where the limiting factor was the aggregation and also in conditions where this aggregation was not the limiting factor. We found that diacylglycerols have a different modulating effect on the Ca(2+)-induced fusion: i) depending on their interfacial conformation, so that 1,2-isomers of diacylglycerols containing unsaturated or short saturated acyl chains stimulated fusion and their 1,3-isomers did not, and ii) depending on their specific type of bilayer interior perturbation, so that diacylglycerols containing unsaturated or short chain saturated acyl chains stimulated fusion but those containing long-chain saturated acyl chains did not. These requirements resembled those required for the diacylglycerol activation of protein kinase C, suggesting that diacylglycerol acts in both the specific activation of this enzyme and the induction of membrane fusion through the same perturbation of lipid structure. We found that polylysine affected the stimulatory role of 1,2-dioleoylglycerol differently, depending on whether aggregation was the limiting factor of fusion. When we studied the effect of very low concentrations of diacylglycerols on the bulk structural properties of phosphatidylserine, we found that they neither significantly perturbed the thermotropic transitions of phosphatidylserine nor affected the interaction of Ca2+ with the phosphate group of phosphatidylserine. The underlying mechanism of fusion between phosphatidylserine vesicles is discussed. PMID:7696508

Temperature Dependence Of Single-Event Effects

NASA Technical Reports Server (NTRS)

Coss, James R.; Nichols, Donald K.; Smith, Lawrence S.; Huebner, Mark A.; Soli, George A.

1990-01-01

Report describes experimental study of effects of temperature on vulnerability of integrated-circuit memories and other electronic logic devices to single-event effects - spurious bit flips or latch-up in logic state caused by impacts of energetic ions. Involved analysis of data on 14 different device types. In most cases examined, vulnerability to these effects increased or remain constant with temperature.

Delay discounting of oral morphine and sweetened juice rewards in dependent and non-dependent rats.

PubMed

Harvey-Lewis, Colin; Perdrizet, Johnna; Franklin, Keith B J

2014-07-01

Opioid-dependent humans are reported to show accelerated delay discounting of opioid rewards when compared to monetary rewards. It has been suggested that this may reflect a difference in discounting of consumable and non-consumable goods not specific to dependent individuals. Here, we evaluate the discounting of similar morphine and non-morphine oral rewards in dependent and non-dependent rats We first tested the analgesic and rewarding effects of our morphine solution. In a second experiment, we assigned rats randomly to either dependent or non-dependent groups that, 30 min after daily testing, received 30 mg/kg subcutaneous dose of morphine, or saline, respectively. Delay discounting of drug-free reward was examined prior to initiation of the dosing regimen. We tested discounting of the morphine reward in half the rats and retested the discounting of the drug-free reward in the other half. All tests were run 22.5 h after the daily maintenance dose. Rats preferred the morphine cocktail to the drug-free solution and consumed enough to induce significant analgesia. The control quinine solution did not produce these effects. Dependent rats discounted morphine rewards more rapidly than before dependence and when compared to discounting drug-free rewards. In non-dependent rats both reward types were discounted similarly. These results show that morphine dependence increases impulsiveness specifically towards a drug reward while morphine experience without dependence does not.

Effects of aqueous, methanolic and chloroform extracts of rhizome and aerial parts of Valeriana officinalis L. on naloxone-induced jumping in morphine-dependent mice.

PubMed

Sharifzadeh, Mohammad; Hadjiakhoondi, Abbas; Khanavi, Mahnaz; Susanabadi, Maryam

2006-06-01

In the present study, the effects of rhizomes and aerial parts extracts of Valeriana officinalis L. on morphine dependence in mice have been investigated. Animals were treated subcutaneously with morphine (50, 50 and 75 mg/kg) three times daily (10 am, 1 pm and 4 pm) for 3 days, and a last dose of morphine (50 mg/kg) was administered on the fourth day. Withdrawal syndrome (jumping) was precipitated by naloxone (5 mg/kg) which was administered intraperitoneally 2 hours after the last dose of morphine. To study the effects of the aqueous, methanolic and chloroform extracts of both aerial parts and rhizome of the V. officinalis L. on naloxone-induced jumping in morphine-dependent animals, 10 injections of morphine (three administrations each day) for dependence and a dose of 5 mg/kg of naloxone for withdrawal induction were employed. Intraperitoneal injection of different doses (1, 5, 25 and 50 mg/kg) of aqueous, methanolic and chloroform extracts of the rhizome of V. officinalis L. 60 minutes before naloxone injection decreased the jumping response dose-dependently. Pre-treatment of animals with different doses (1, 5, 25, 50 and 100 mg/kg) of aqueous and methanolic extracts of aerial parts of V. officinalis L. 60 minutes before naloxone injection caused a significant decrease on naloxone-induced jumping. The chloroform extract of the aerial parts of V. officinalis L. did not show any significant changes on jumping response in morphine-dependent animals. It is concluded that the extracts of V. officinalis L. could affect morphine withdrawal syndrome via possible interactions with inhibitory neurotransmitters in nervous system.

The Effect of Two Benzodiazepine Receptor Agonist Hypnotics on Sleep-Dependent Memory Consolidation

PubMed Central

Hall-Porter, Janine M.; Schweitzer, Paula K.; Eisenstein, Rhody D.; Ahmed, Hasan Ali H.; Walsh, James K.

2014-01-01

Introduction: Numerous studies have demonstrated that sleep promotes memory consolidation, but there is little research on the effect of hypnotics on sleep-dependent memory consolidation. We compared bedtime administration of zolpidem-ER 12.5 mg (6- to 8-h duration of action), middle-of-the-night administration of zaleplon 10 mg (3- to 4-h duration of action), and placebo to examine the effect of different durations of hypnotic drug exposure on memory consolidation during sleep. Methods: Twenty-two participants with no sleep complaints underwent 3 conditions in a counterbalanced crossover study: (1) zolpidem-ER 12.5 mg (bedtime dosing), (2) zaleplon 10 mg (middle-of-the-night dosing), and (3) placebo. Memory testing was conducted before and after an 8-h sleep period, using a word pair association task (WPT; declarative memory) and a finger-tapping task (FTT; procedural memory). Results: ANOVA revealed a significant condition effect for the WPT (p = 0.025) and a trend for the FTT (p = 0.067), which was significant when sex was added to the model (p = 0.014). Improvement in memory performance following sleep was lower with bedtime dosing of zolpidem-ER compared to placebo and middle-of-the-night dosing of zaleplon. There were no differences between placebo and zaleplon. Conclusions: The results suggest that in some circumstances hypnotics may have the potential to reduce the degree of sleep-dependent memory consolidation and that drug-free sleep early in the night may ameliorate this effect. Citation: Hall-Porter JM; Schweitzer PK; Eisenstein RD; Ahmed HAH; Walsh JK. The effect of two benzodiazepine receptor agonist hypnotics on sleep-dependent memory consolidation. J Clin Sleep Med 2014;10(1):27-34. PMID:24426817

Theory of nitrogen doping of carbon nanoribbons: Edge effects

DOE PAGES

Jiang, Jie; Turnbull, Joseph; Lu, Wenchang; ...

2012-01-01

Nitrogen doping of a carbon nanoribbon is profoundly affected by its one-dimensional character, symmetry, and interaction with edge states. Using state-of-the-art ab initio calculations, including hybrid exact-exchange density functional theory, we find that, for N-doped zigzag ribbons, the electronic properties are strongly dependent upon sublattice effects due to the non-equivalence of the two sublattices. For armchair ribbons, N-doping effects are different depending upon the ribbon family: for families 2 and 0, the N-induced levels are in the conduction band, while for family 1 the N levels are in the gap. In zigzag nanoribbons, nitrogen close to the edge is amore » deep center, while in armchair nanoribbons its behavior is close to an effective-mass-like donor with the ionization energy dependent on the value of the band gap. In chiral nanoribbons, we find strong dependence of the impurity level and formation energy upon the edge position of the dopant, while such site-specificity is not manifested in the magnitude of the magnetization.« less

[Combined effects of arbekacin with other antibiotics against methicillin-resistant Staphylococcus aureus. IV. Combined effects of arbekacin with cefmetazole or flomoxef].

PubMed

Deguchi, K; Yokota, N; Koguchi, M; Nakane, Y; Suzuki, Y; Suzuki, K; Fukayama, S; Ishihara, R; Oda, S

1992-10-01

Antibacterial effects of combination use of arbekacin (ABK) with cefmetazole (CMZ) or flomoxef (FMOX) were evaluated against methicillin-resistant Staphylococcus aureus (MRSA) and the following results were obtained. 1. Antibacterial effects of combinations of ABK with CMZ and with FMOX were equally potent against MRSA at clinically expected 1 MIC of ABK in blood. However, at a sub MIC of ABK different effects were observed between the 2 combinations. The former combination was slightly less effective than the latter. 2. In either combination the potency of the antibacterial activity was less dependent on the concentration of CMZ or FMOX, but was strongly dependent on ABK concentrations. These results suggest that antibacterial effects of the combinations were highly dependent on antibacterial potency and concentration of ABK as previously reported for combinations of ABK with other drugs. 3. It appears that the antibacterial activity of the combination of the sub MIC of ABK with a beta-lactam is an important point in considering the effectiveness of a combination therapy.

Improving Planck calibration by including frequency-dependent relativistic corrections

NASA Astrophysics Data System (ADS)

Quartin, Miguel; Notari, Alessio

2015-09-01

The Planck satellite detectors are calibrated in the 2015 release using the "orbital dipole", which is the time-dependent dipole generated by the Doppler effect due to the motion of the satellite around the Sun. Such an effect has also relativistic time-dependent corrections of relative magnitude 10-3, due to coupling with the "solar dipole" (the motion of the Sun compared to the CMB rest frame), which are included in the data calibration by the Planck collaboration. We point out that such corrections are subject to a frequency-dependent multiplicative factor. This factor differs from unity especially at the highest frequencies, relevant for the HFI instrument. Since currently Planck calibration errors are dominated by systematics, to the point that polarization data is currently unreliable at large scales, such a correction can in principle be highly relevant for future data releases.

Dependency and self-criticism in treatments for depression.

PubMed

Chui, Harold; Zilcha-Mano, Sigal; Dinger, Ulrike; Barrett, Marna S; Barber, Jacques P

2016-07-01

Dependency and self-criticism are vulnerability factors for depression. How these personality factors change with treatment for depression and how they relate to symptom change across different types of treatment require further research. In addition, cultural differences that interact with the dependency/self-criticism-depression relation remain underinvestigated. We randomly assigned 149 adults with major depression to receive active medication (MED; n = 50), supportive-expressive therapy (SET; n = 49), or placebo pill (PBO; n = 50). Participants completed the Depressive Experiences Questionnaire (DEQ; Blatt, D'Afflitti, & Quinlan, 1976) before and after treatment and completed the Hamilton Rating Scale for Depression (Hamilton, 1967) throughout the course of treatment. Self-criticism as measured on the DEQ decreased with treatment similarly across conditions. DEQ Dependency decreased in MED but remained unchanged in SET and PBO. Higher initial dependency, but not higher initial self-criticism, predicted poor treatment response across conditions. Greater reduction in self-criticism was associated with greater reduction in depressive symptoms, but the effect was weaker for racial minorities (vs. White). Increase in connectedness, an adaptive form of dependency, was associated with symptom improvement in SET but not MED. Hence, different pathways of change seem to be implicated in the treatment of depression depending on culture and type of intervention. Implications for future research are discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Dynamical Analysis of Density-dependent Selection in a Discrete one-island Migration Model

Treesearch

James H. Roberds; James F. Selgrade

2000-01-01

A system of non-linear difference equations is used to model the effects of density-dependent selection and migration in a population characterized by two alleles at a single gene locus. Results for the existence and stability of polymorphic equilibria are established. Properties for a genetically important class of equilibria associated with complete dominance in...

Plastic scintillation detectors for dose monitoring in digital breast tomosynthesis

NASA Astrophysics Data System (ADS)

Antunes, J.; Machado, J.; Peralta, L.; Matela, N.

2018-01-01

Plastic scintillators detectors (PSDs) have been studied as dosimeters, since they provide a cost-effective alternative to conventional ionization chambers. Measurement and analysis of energy dependency were performed on a Siemens Mammomat tomograph for two different peak kilovoltages: 26 kV and 35 kV. Both PSD displayed good linearity for each energy considered and almost no energy dependence.

Repeated restraint stress enhances cue-elicited conditioned freezing and impairs acquisition of extinction in an age-dependent manner

PubMed Central

Zhang, Wei; Rosenkranz, J. Amiel

2013-01-01

Affective disorders are believed to involve dysfunction within the amygdala, a key structure for processing emotional information. Chronic stress may contribute to affective disorders such as depression and anxiety via its effects on the amygdala. Previous research has shown that chronic stress increases amygdala neuronal activity in an age-dependent manner. However, whether these distinct changes in amgydala neuronal activity are accompanied by age-dependent changes in amygdala-dependent affective behavior is unclear. In this study, we investigated how chronic stress impacts amgydala-dependent auditory fear conditioning in adolescent and adult rats in a repeated restraint model. We found that repeated restraint enhanced conditioned freezing in both adolescent and adult rats. But repeated restraint led to impaired acquisition of fear extinction only in adolescent rats. Along with previous findings, these results suggest that chronic stress may precipitate affective disorders via differential mechanisms, with different outcomes at different ages. PMID:23538069

Mucosal and systemic adjuvant effects of cholera toxin and Cry1Ac protoxin on the specific antibody response to HIV-1 C4/V3 peptides are different and depend on the antigen co-administered.

PubMed

Esquivel-Pérez, Rita; Moreno-Fierros, Leticia

2005-01-01

Evidence from several sources support the assertion that cholera toxin (CT) is a potent immunogen and mucosal adjuvant; however there are also reports showing its lack of adjuvanticity against some antigens. Cry1Ac protoxin also exerts adjuvant effects in the antibody responses to proteins and polysaccharides but its adjuvanticity with regard to peptide vaccines had not been tested. To probe whether the adjuvant effects of these proteins varied depending on the antigen co-administered, we evaluated antipeptide antibody responses in serum and mucosal samples (vaginal, intestinal, and pulmonary) of mice that were immunized by intranasal or intraperitoneal routes with one of two distinct hybrid C4/V3 HIV peptides, either alone or with CT or Cry1Ac. The tested HIV 1 peptides differed in two aminoacids, T1SP10MN(A) was modified at the SP10 region by the substitution of the isoleucines 12 and 14 for cysteines and was called modified (m)T1SP10MN(A). Our data indicate that the adjuvant effects of CT and Cry1Ac are different. In addition they vary depending on the antigen co-administered and the number of antigen doses, because after three doses moderate adjuvant effects of CT and Cry1Ac on anti-peptide serum and mucosal antibody responses were observed only against the mT1SP10MN(A). In contrast, to attain significant adjuvant effects against the T1SP10MN, four doses were required. Interestingly we found that modification of the HIV peptide increases its immunogenicity without altering the principal neutralizing determinant (SP10).

Rehabilitating sea otters: Feeling good versus being effective; Chapter 20

USGS Publications Warehouse

Estes, James A.; Tinker, M. Tim; Kareiva, Peter; Marvier, Michelle; Silliman, Brian

2017-01-01

This chapter examines the complexities of assessing the merits and drawbacks of wildlife rehabilitation. Wildlife rehabilitation is often costly, and the resulting benefits differ depending on whether one’s interest is in the welfare of individual animals or conserving populations. Two examples of this dilemma include the rehabilitation of oiled sea otters following the Exxon Valdez spill in Prince William Sound, Alaska, and the rehabilitation of stranded sea otter pups in central California. In the first example, substantial financial investment resulted in little or no benefits for population conservation. In the second example, the potential for population-level benefits is context dependent: in populations near carrying capacity the conservation impacts are negligible, whereas in isolated, low-density populations rehabilitation and release can be an effective conservation tool. Wildlife rehabilitation is valued by people for various reasons, but recognizing and acknowledging the difference between individual and population welfare is an important step toward effective wildlife conservation.

Long-range effect of a Zeeman field on the electric current through the helical metal-superconductor interface in an Andreev interferometer

NASA Astrophysics Data System (ADS)

Mal'shukov, A. G.

2018-02-01

It is shown that the spin-orbit and Zeeman interactions result in phase shifts of Andreev-reflected holes propagating at the surface of a topological insulator, or in Rashba spin-orbit-coupled two-dimensional normal metals, which are in contact with an s -wave superconductor. Due to interference of holes reflected through different paths of the Andreev interferometer the electric current through external contacts varies depending on the strength and direction of the Zeeman field. It also depends on mutual orientations of Zeeman fields in different shoulders of the interferometer. Such a nonlocal effect is a result of the long-range coherency caused by the superconducting proximity effect. This current has been calculated within the semiclassical theory for Green's functions in the diffusive regime, by assuming a strong disorder due to elastic scattering of electrons.

Wetting layer effect on impurity-related electronic properties of different (In,Ga)N QD-shapes

NASA Astrophysics Data System (ADS)

El Ghazi, Haddou; Jorio, Anouar; Zorkani, Izeddine; Feddi, El Mustapha; El Mouchtachi, Ahmed

2018-05-01

In this paper, we have investigated the electronic properties of (In,Ga)N/GaN coupled wetting layer-quantum dot system using the numerical approach. The finite element method code is used to solve the Schrödinger equation, in the presence of the impurity. In our model, parallelepiped-shape, circular and square based-pyramidal and their wetting layers embedded in GaN matrix were considered. Based on the single band parabolic and the effective mass approximations, the envelop function and its corresponding energy eigenvalue are obtained assuming a finite potential barrier. Our results reveal that: (1) the wetting layer has a great influence on the electronic properties especially for a small quantum dot and acts in the opposite sense of the geometrical confinement, (2) a wetting layer-dependent critical QD-size is obtained limiting two different behaviors and (3) its effect is strongly-dependent on the quantum dot-shape.

In vitro effects of 5-hydroxytryptophan, indoleamines and leptin on arylalkylamine N-acetyltransferase (AA-NAT) activity in pineal organ of the fish, Clarias gariepinus (Burchell, 1822) during different phases of the breeding cycle.

PubMed

Gupta, B B P; Yanthan, L; Singh, Ksh Manisana

2010-08-01

Arylalkylamine N-acetyltransferase (AA-NAT) is the rate-limiting enzyme of melatonin biosynthetic pathway. In vitro effects of 5-hydroxytryptophan (5-HTP) and indoleamines (serotonin, N-acetylserotonin and melatonin) were studied on AA-NAT activity in the pineal organ of the fish, C. gariepinus during different phases of its annual breeding cycle. Further, in vitro effects of leptin on AA-NAT activity in the pineal organ were studied in fed and fasted fishes during summer and winter seasons. Treatments with 5-HTP and indoleamines invariably stimulated pineal AA-NAT activity in a dose-dependent manner during all the phases. However, leptin increased AA-NAT activity in a dose-dependent manner only in the pineal organ of the fed fishes, but not of the fasted fishes irrespective of the seasons.

Large current modulation and spin-dependent tunneling of vertical graphene/MoS2 heterostructures.

PubMed

Myoung, Nojoon; Seo, Kyungchul; Lee, Seung Joo; Ihm, G

2013-08-27

Vertical graphene heterostructures have been introduced as an alternative architecture for electronic devices by using quantum tunneling. Here, we present that the current on/off ratio of vertical graphene field-effect transistors is enhanced by using an armchair graphene nanoribbon as an electrode. Moreover, we report spin-dependent tunneling current of the graphene/MoS2 heterostructures. When an atomically thin MoS2 layer sandwiched between graphene electrodes becomes magnetic, Dirac fermions with different spins feel different heights of the tunnel barrier, leading to spin-dependent tunneling. Our finding will develop the present graphene heterostructures for electronic devices by improving the device performance and by adding the possibility of spintronics based on graphene.

Visual cues that are effective for contextual saccade adaptation.

PubMed

Azadi, Reza; Harwood, Mark R

2014-06-01

The accuracy of saccades, as maintained by saccade adaptation, has been shown to be context dependent: able to have different amplitude movements to the same retinal displacement dependent on motor contexts such as orbital starting location. There is conflicting evidence as to whether purely visual cues also effect contextual saccade adaptation and, if so, what function this might serve. We tested what visual cues might evoke contextual adaptation. Over 5 experiments, 78 naive subjects made saccades to circularly moving targets, which stepped outward or inward during the saccade depending on target movement direction, speed, or color and shape. To test if the movement or context postsaccade were critical, we stopped the postsaccade target motion (experiment 4) or neutralized the contexts by equating postsaccade target speed to an intermediate value (experiment 5). We found contextual adaptation in all conditions except those defined by color and shape. We conclude that some, but not all, visual cues before the saccade are sufficient for contextual adaptation. We conjecture that this visual contextuality functions to allow for different motor states for different coordinated movement patterns, such as coordinated saccade and pursuit motor planning. Copyright © 2014 the American Physiological Society.

Influence of COMT Val158Met polymorphism on emotional decision-making: A sex-dependent relationship?

PubMed

Costa, Danielle de Souza; Bechara, Antoine; de Paula, Jonas Jardim; Romano-Silva, Marco Aurélio; Correa, Humberto; Lage, Guilherme Menezes; Miranda, Débora Marques de; Malloy-Diniz, Leandro Fernandes

2016-12-30

The biological underpinnings of sex-related differences in decision-making are still under-explored. The COMT gene is related to sexual dimorphism and with different choices made under uncertainty, albeit no study has specifically investigated a moderation effect of sex on the association between the COMT gene and the performance on decision-making paradigms. In this study, we investigated the influence of the COMT Val 158 Met polymorphism on Iowa Gambling Task (IGT) performance depending on sex in a healthy adult sample. Participants were 192 healthy adults (84 men and 108 women). The first 40 choices in the IGT were considered decisions under ambiguity and the last 60 choices decisions under risk. To test our moderation hypothesis we used a separate regressions approach. The results revealed a sex-dependent effect of COMT Va l 158 Met polymorphism on decision-making as measured by the IGT. Val/Val women showed the best performance in the last trials of the IGT. Therefore, the COMT Val 158 Met polymorphism may be considered a genetic marker underlying sex differences in decision-making. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Persistent inhibition of hippocampal long-term potentiation in vivo by learned helplessness stress.

PubMed

Ryan, Benedict K; Vollmayr, Barbara; Klyubin, Igor; Gass, Peter; Rowan, Michael J

2010-06-01

The persistent cognitive disruptive effects of stress have been strongly implicated in the pathophysiology of depression and post-traumatic stress disorder. Here we examined factors influencing the time course of recovery from the inhibitory effect of acute inescapable stressors on the ability to induce long-term potentiation (LTP) in the dorsal hippocampus in vivo. We tested different forms of LTP, different stressors and different inbred strains of rats. Acute elevated platform stress completely, but transiently (<3 h), inhibited induction of both NMDA receptor-dependent LTP induced by a standard high frequency (200 Hz) conditioning stimulus and an additional LTP that required voltage-dependent Ca(2+) channel activation triggered by strong (400 Hz) conditioning stimulation. In contrast, acute inescapable footshock stress, used to study learned helplessness, inhibited LTP for at least 4 weeks. Contrary to expectations, there was no clear relationship between the ability of the footshock to trigger helpless behavior, a model of stress-induced depression, and the magnitude of LTP inhibition. Moreover, LTP did not appear to be affected by genetic susceptibility to learned helplessness, a model of genetic vulnerability to depression. This long-lasting synaptic plasticity disruption may underlie persistent impairment of hippocampus-dependent cognition by excessive acute inescapable stress.

Non-equilibrium effects on the chemistry of nebular condensates - Implications for the planets and asteroids

NASA Technical Reports Server (NTRS)

Blander, M.

1979-01-01

Kinetic effects, for example nucleation constraints and slow reactions, should have been important in nebular condensation. Consideration of these effects leads to the prediction of pressure-dependent compositions and physical properties of nebular condensates which is consistent with (1) the differences between different classes of chondritic meteorites, (2) some of the differences between planets, and (3) the presence of oxidized iron on the moon and in the eucrite parent body (presumably an asteroid) despite the low abundance of volatiles. Diffusion effects appear to be important for understanding oxygen isotope anomalies in refractory inclusions in Allende. The consideration of kinetic effects leads to more information concerning nebular processes than if equilibrium is assumed.

Oral warfarin affects peripheral blood leukocyte IL-6 and TNFα production in rats.

PubMed

Popov, Aleksandra; Belij, Sandra; Subota, Vesna; Zolotarevski, Lidija; Mirkov, Ivana; Kataranovski, Dragan; Kataranovski, Milena

2013-01-01

Warfarin is a Vitamin K (VK) antagonist that affects Vitamin K-dependent (VKD) processes, including blood coagulation, as well as processes unrelated to hemostasis such as bone growth, calcification, and growth of some cell types. In addition, warfarin exerts influence on some non-VKD-related activities, including anti-tumor and immunomodulating activity. With respect to the latter, both immune stimulating and suppressive effects have been noted in different experimental systems. To explore the in vivo immunomodulatory potential of warfarin on one type of activity (i.e., cytokine production) in two different immune cell populations (i.e., mononuclear or polymorphonuclear cells), effects of subchronic oral warfarin intake in rats on pro-inflammatory cytokine (i.e., TNFα, IL-6) production by peripheral blood mononuclear and polymorphonuclear cells (granulocytes) was examined. Differential effects of warfarin intake on TNFα and IL-6 were noted, depending on the type of peripheral blood leukocytes and on the cytokine examined. Specifically, a lack of effect on TNFα and a priming of IL-6 production by mononuclear cells along with a decrease in TNFα and a lack of effect on IL-6 in polymorphonuclear cells were seen in warfarin-exposed hosts. The cell- and cytokine-dependent effects from subchronic oral warfarin intake on peripheral blood leukocytes demonstrated in this study could, possibly, differentially affect reactions mediated by these cells. Ultimately, the observed effects in rats might have implications for those humans who are on long-term/prolonged warfarin therapy.

Stimulatory effect of insulin on 5alpha-reductase type 1 (SRD5A1) expression through an Akt-dependent pathway in ovarian granulosa cells.

PubMed

Kayampilly, Pradeep P; Wanamaker, Brett L; Stewart, James A; Wagner, Carrie L; Menon, K M J

2010-10-01

Elevated levels of 5α-reduced androgens have been shown to be associated with hyperandrogenism and hyperinsulinemia, the leading causes of ovulatory dysfunction in women. 5α-Dihydrotestosterone reduces ovarian granulosa cell proliferation by inhibiting FSH-mediated mitogenic signaling pathways. The present study examined the effect of insulin on 5α-reductase, the enzyme that catalyses the conversion of androgens to their 5α-derivatives. Granulosa cells isolated from immature rat ovaries were cultured in serum-free, phenol red-free DMEM-F12 media and treated with different doses of insulin (0, 0.1, 1.0, and 10.0 μg/ml) for different time intervals up to 12 h. The expression of 5α-reductase type 1 mRNA, the predominant isoform found in granulosa cells, showed a significant (P<0.05) increase in response to the insulin treatment up to 12 h compared with control. The catalytic activity of 5α-reductase enzyme was also stimulated in a dose-depended manner (P<0.05). Inhibiting the Akt-dependent signaling pathway abolished the insulin-mediated increase in 5α-reductase mRNA expression, whereas inhibition of the ERK-dependent pathway had no effect. The dose-dependent increase in 5α-reductase mRNA expression as well as catalytic activity seen in response to insulin treatment was also demonstrated in the human granulosa cell line (KGN). In addition to increased mRNA expression, a dose-dependent increase in 5α-reductase protein expression in response to insulin was also seen in KGN cells, which corroborated well with that of mRNA expression. These results suggest that elevated levels of 5α-reduced androgens seen in hyperinsulinemic conditions might be explained on the basis of a stimulatory effect of insulin on 5α-reductase in granulosa cells. The elevated levels of these metabolites, in turn, might adversely affect growth and proliferation of granulosa cells, thereby impairing follicle growth and ovulation.

Effect of Position- and Velocity-Dependent Forces on Reaching Movements at Different Speeds

PubMed Central

Summa, Susanna; Casadio, Maura; Sanguineti, Vittorio

2016-01-01

The speed of voluntary movements is determined by the conflicting needs of maximizing accuracy and minimizing mechanical effort. Dynamic perturbations, e.g., force fields, may be used to manipulate movements in order to investigate these mechanisms. Here, we focus on how the presence of position- and velocity-dependent force fields affects the relation between speed and accuracy during hand reaching movements. Participants were instructed to perform reaching movements under visual control in two directions, corresponding to either low or high arm inertia. The subjects were required to maintain four different movement durations (very slow, slow, fast, very fast). The experimental protocol included three phases: (i) familiarization—the robot generated no force; (ii) force field—the robot generated a force; and (iii) after-effect—again, no force. Participants were randomly assigned to four groups, depending on the type of force that was applied during the “force field” phase. The robot was programmed to generate position-dependent forces—with positive (K+) or negative stiffness (K−)—or velocity-dependent forces, with either positive (B+) or negative viscosity (B−). We focused on path curvature, smoothness, and endpoint error; in the latter we distinguished between bias and variability components. Movements in the high-inertia direction are smoother and less curved; smoothness also increases with movement speed. Endpoint bias and variability are greater in, respectively, the high and low inertia directions. A robust dependence on movement speed was only observed in the longitudinal components of both bias and variability. The strongest and more consistent effects of perturbation were observed with negative viscosity (B−), which resulted in increased variability during force field adaptation and in a reduction of the endpoint bias, which was retained in the subsequent after-effect phase. These findings confirm that training with negative viscosity produces lasting effects in movement accuracy at all speeds. PMID:27965559

Effectiveness of Blog Response Strategies to Minimize Crisis Effects

ERIC Educational Resources Information Center

Tomsic, Louis P.

2010-01-01

This study examined the effects of four post-crisis responses on five different variables using a blog tool. The four post-crisis responses are information only, compensation, apology, and sympathy. The five dependent variables are reputation, anger (negative emotion), negative word-of-mouth, account acceptance and state of the publics based on…

Effective School Evaluation in Primary Schools from the Dimension of Parents

ERIC Educational Resources Information Center

Akan, Durdagi

2017-01-01

The aim of this study is to analyze the effectiveness of the primary schools depending on "parents" dimension according to the perceptions of administrator and teacher in terms of different variables. It employed descriptive survey model. Data was collected through effective school questionnaire with the aim of determining the…

Electrically Addressable Optical Devices Using A System Of Composite Layered Flakes Suspended In A Fluid Host To Obtain Angularly Depende

DOEpatents

Kosc, Tanya Z.; Marshall, Kenneth L.; Jacobs, Stephen D.

2004-12-07

Composite or layered flakes having a plurality of layers of different materials, which may be dielectric materials, conductive materials, or liquid crystalline materials suspended in a fluid host and subjected to an electric field, provide optical effects dependent upon the angle or orientation of the flakes in the applied electric field. The optical effects depend upon the composition and thickness of the layers, producing reflectance, interference, additive and/or subtractive color effects. The composition of layered flakes may also be selected to enhance and/or alter the dielectric properties of flakes, whereby flake motion in an electric field is also enhanced and/or altered. The devices are useful as active electro-optical displays, polarizers, filters, light modulators, and wherever controllable polarizing, reflecting and transmissive optical properties are desired.

Unexpected variations in the triple oxygen isotope composition of stratospheric carbon dioxide

NASA Astrophysics Data System (ADS)

Wiegel, Aaron A.; Cole, Amanda S.; Hoag, Katherine J.; Atlas, Elliot L.; Schauffler, Sue M.; Boering, Kristie A.

2013-10-01

We report observations of stratospheric CO2 that reveal surprisingly large anomalous enrichments in 17O that vary systematically with latitude, altitude, and season. The triple isotope slopes reached 1.95 ± 0.05(1σ) in the middle stratosphere and 2.22 ± 0.07 in the Arctic vortex versus 1.71 ± 0.03 from previous observations and a remarkable factor of 4 larger than the mass-dependent value of 0.52. Kinetics modeling of laboratory measurements of photochemical ozone-CO2 isotope exchange demonstrates that non-mass-dependent isotope effects in ozone formation alone quantitatively account for the 17O anomaly in CO2 in the laboratory, resolving long-standing discrepancies between models and laboratory measurements. Model sensitivities to hypothetical mass-dependent isotope effects in reactions involving O3, O(1D), or CO2 and to an empirically derived temperature dependence of the anomalous kinetic isotope effects in ozone formation then provide a conceptual framework for understanding the differences in the isotopic composition and the triple isotope slopes between the laboratory and the stratosphere and between different regions of the stratosphere. This understanding in turn provides a firmer foundation for the diverse biogeochemical and paleoclimate applications of 17O anomalies in tropospheric CO2, O2, mineral sulfates, and fossil bones and teeth, which all derive from stratospheric CO2.

Parental Legacy in Insects: Variation of Transgenerational Immune Priming during Offspring Development

PubMed Central

Trauer, Ute; Hilker, Monika

2013-01-01

In insects, a parental immune challenge can prepare and enhance offspring immune activity. Previous studies of such transgenerational immune priming (TGIP) mainly focused on a single offspring life stage. However, different developmental stages may be exposed to different risks and show different susceptibility to parental immune priming. Here we addressed the question (i) whether TGIP effects on the immunity of Manduca sexta offspring vary among the different developmental offspring stages. We differentiated between unchallenged and immunochallenged offspring; for the latter type of offspring, we further investigated (ii) whether TGIP has an impact on the time that enhanced immune levels persist after offspring immune challenge. Finally, we determined (iii) whether TGIP effects on offspring performance depend on the offspring stage. Our results show that TGIP effects on phenoloxidase (PO) activity, but not on antibacterial activity, vary among unchallenged offspring stages. In contrast, TGIP effects on PO and antibacterial activity did not vary among immunochallenged offspring stages. The persistence of enhanced immune levels in immunochallenged offspring was dependent on the parental immune state. Antibacterial (but not PO) activity in offspring of immunochallenged parents decreased over five days after pupal immune challenge, whereas no significant change over time was detectable in offspring of control parents. Finally, TGIP effects on the developmental time of unchallenged offspring varied among stages; young larvae of immunochallenged parents developed faster and gained more weight than larvae of control parents. However, offspring females of immunochallenged parents laid fewer eggs than females derived from control parents. These findings suggest that the benefits which the offspring gains from TGIP during juvenile development are paid by the adults with reduced reproductive power. Our study shows that TGIP effects vary among offspring stages and depend on the type of immunity (PO or antibacterial activity) as well as the time past offspring immune challenge. PMID:23700423

Different effects of high- and low-dose phenobarbital on post-stroke seizure suppression and recovery in immature CD1 mice

PubMed Central

Markowitz, Geoffrey J.; Kadam, Shilpa D.; Smith, Dani R.; Johnston, Michael V.; Comi, Anne M.

2011-01-01

Neonatal stroke presents with seizures that are usually treated with phenobarbital. We hypothesized that anticonvulsants would attenuate ischemic injury, but that the dose-dependent effects of standard anticonvulsants would impact important age-dependent and injury-dependent consequences. In this study, ischemia induced by unilateral carotid ligation in postnatal day 12 (P12) CD1 mice was immediately followed by an i.p. dose of vehicle, low-dose or high-dose phenobarbital. Severity of acute behavioral seizures was scored. 5-bromo-2’-deoxyuridine (BrdU) was administered from P18-P20, behavioral testing performed, and mice perfused at P40. Atrophy quantification and counts of BrdU/NeuN-labeled cells in the dentate gyrus were performed. Blood phenobarbital concentrations were measured. 30 mg/kg phenobarbital reduced acute seizures and chronic brain injury, and restored normal weight gain and exploratory behavior. By comparison, 60 mg/kg was a less efficacious anticonvulsant, was not neuroprotective, did not restore normal weight gain, and impaired behavioral and cognitive recovery. Hippocampal neurogenesis was not different between treatment groups. These results suggest a protective effect of lower-dose phenobarbital, but a lack of this effect at higher concentrations after stroke in P12 mice. PMID:21481568

Unfolding grain size effects in barium titanate ferroelectric ceramics

PubMed Central

Tan, Yongqiang; Zhang, Jialiang; Wu, Yanqing; Wang, Chunlei; Koval, Vladimir; Shi, Baogui; Ye, Haitao; McKinnon, Ruth; Viola, Giuseppe; Yan, Haixue

2015-01-01

Grain size effects on the physical properties of polycrystalline ferroelectrics have been extensively studied for decades; however there are still major controversies regarding the dependence of the piezoelectric and ferroelectric properties on the grain size. Dense BaTiO3 ceramics with different grain sizes were fabricated by either conventional sintering or spark plasma sintering using micro- and nano-sized powders. The results show that the grain size effect on the dielectric permittivity is nearly independent of the sintering method and starting powder used. A peak in the permittivity is observed in all the ceramics with a grain size near 1 μm and can be attributed to a maximum domain wall density and mobility. The piezoelectric coefficient d33 and remnant polarization Pr show diverse grain size effects depending on the particle size of the starting powder and sintering temperature. This suggests that besides domain wall density, other factors such as back fields and point defects, which influence the domain wall mobility, could be responsible for the different grain size dependence observed in the dielectric and piezoelectric/ferroelectric properties. In cases where point defects are not the dominant contributor, the piezoelectric constant d33 and the remnant polarization Pr increase with increasing grain size. PMID:25951408

Effect of annealing on magnetoresistance and microstructure of multilayered CoFe/Cu systems with different buffer layer

NASA Astrophysics Data System (ADS)

Bannikova, N. S.; Milyaev, M. A.; Naumova, L. I.; Proglyado, V. V.; Krinitsina, T. P.; Chernyshova, T. A.; Ustinov, V. V.

2015-02-01

The effects of annealing on the structure, magnetic hysteresis, and magnetoresistance of [Co90Fe10(15 Å)/Cu(23 Å)] n superlattices with Cr and Co90Fe10 buffer layers of different thicknesses have been studied. The optimum temperature and time of annealing that increase the magnetoresistance were shown to depend on the buffer layer thickness. The coefficients of effective interlayer diffusion due to the annealing have been determined.

Sex-Dependent Effects of Cannabis and Cannabinoids: A Translational Perspective.

PubMed

Cooper, Ziva D; Craft, Rebecca M

2018-01-01

Recent policy changes have led to significant increases in the use of cannabis for both medical and recreational purposes. Although men are more likely to endorse past month cannabis use and are more frequently diagnosed with Cannabis Use Disorder relative to women, a growing proportion of medical cannabis users are reported to be women. The increased popularity of cannabis for medical purposes and the narrowing gap in prevalence of use between men and women raises questions regarding sex-dependent effects related to therapeutic efficacy and negative health effects of cannabis and cannabinoids. The objective of this review is to provide a translational perspective on the sex-dependent effects of cannabis and cannabinoids by synthesizing findings from preclinical and clinical studies focused on sex comparisons of their therapeutic potential and abuse liability, two specific areas that are of significant public health relevance. Hormonal and pharmacological mechanisms that may underlie sex differences in the effects of cannabis and cannabinoids are highlighted.

YORP effect on real objects. I. Statistical properties

NASA Astrophysics Data System (ADS)

Micheli, M.; Paolicchi, P.

2008-10-01

Context: The intensity of the YORP (Yarkovsky, O'Keefe, Radzievskii, and Paddack) effect and its ability to affect the rotational properties of asteroids depend mainly on the size of the body and on its shape. At present, we have a database of about 30 well-defined shapes of real minor bodies (most of them asteroids, but also planetary satellites and cometary nuclei). Aims: In this paper we perform a statistical analysis of how the YORP effect depends on the shape. Methods: We used the Rubincam approximation (i.e. neglecting the effects of a finite thermal conductivity). Results: We show that, among real bodies, the distribution of the YORP types, according to the classification of Vokrouhlický and Čapek, is significantly different from the one obtained in the same paper from theoretical modeling of shapes. A new “type” also comes out. Moreover, we show that the types are strongly correlated with the intensity of the YORP effect (when normalized to eliminate the dependence on the size, and thus only related to the shape).

Naltrexone versus acamprosate in the treatment of alcohol dependence: A multi-centre, randomized, double-blind, placebo-controlled trial.

PubMed

Morley, Kirsten C; Teesson, Maree; Reid, Sophie C; Sannibale, Claudia; Thomson, Clare; Phung, Nghi; Weltman, Martin; Bell, James R; Richardson, Kylie; Haber, Paul S

2006-10-01

To compare the efficacy of acamprosate and naltrexone in the treatment of alcohol dependence. A double-blind, placebo-controlled trial. Three treatment centres in Australia. A total of 169 alcohol dependent subjects were given naltrexone (50 mg/day), acamprosate (1998 mg/day) or placebo for 12 weeks. All subjects were offered manualized compliance therapy, a brief intervention that targets problems that may affect treatment compliance such as ambivalence and misperceptions about medication. Time to the first drink, time to first relapse, drinks per drinking day and cumulative abstinence. In intention-to-treat analyses, there were no differences between groups on outcome measures of drinking, craving or biochemical markers. Similarly, analyses of the 94 subjects that completed the study in full and demonstrated 80% compliance, revealed no significant treatment effects. Differential treatment effects were identified after stratification according to scores on the Alcohol Dependence Scale (ADS) and Depression Anxiety and Stress Scale (DASS). A significant beneficial treatment effect on time to first relapse was revealed for subjects with 'no depression' allocated to naltrexone (n = 56; P < 0.01). In addition, a significant beneficial treatment effect was revealed in subjects with 'low dependence' allocated to naltrexone (n = 34; P < 0.05). The results of this study support the efficacy of naltrexone in the relapse prevention of alcoholism amongst those with low levels of clinical depression and alcohol dependence severity. No effect of acamprosate was found in our sample.

Environmental risk assessment of effluents as a whole emerging contaminant: Efficiency of alternative tertiary treatments for wastewater depuration.

PubMed

Díaz-Garduño, B; Pintado-Herrera, M G; Biel-Maeso, M; Rueda-Márquez, J J; Lara-Martín, P A; Perales, J A; Manzano, M A; Garrido-Pérez, C; Martín-Díaz, M L

2017-08-01

Emerging contaminants (ECs) and regulated compounds (RCs) from three different WWTP effluents were measured in the current study. The efficiency of two tertiary treatments, Photobiotreatment (PhtBio) and Multi-Barrier Treatment (MBT), for removing contaminants was determined. Results indicated different percentages of removal depending on the treatment and the origin of the effluent. Risk Quotients (RQs) were determined for different species of algae, Daphnia, and fish. RQ results revealed diverse risk values depending on the bioindicator species. Tonalide, galaxolide (fragrances), and ofloxacin (antibiotic) were the most persistent and harmful substances in tested effluents. "Negligible risk" category was reached since a wide diversity of ECs were removed by MBT with high removal percentages. Contrarily, PhtBio was effective only in the depuration of certain chemical compounds, and its efficiency depended on the composition of the raw effluent. Copyright © 2017 Elsevier Ltd. All rights reserved.

ANCOVA Versus CHANGE From Baseline in Nonrandomized Studies: The Difference.

PubMed

van Breukelen, Gerard J P

2013-11-01

The pretest-posttest control group design can be analyzed with the posttest as dependent variable and the pretest as covariate (ANCOVA) or with the difference between posttest and pretest as dependent variable (CHANGE). These 2 methods can give contradictory results if groups differ at pretest, a phenomenon that is known as Lord's paradox. Literature claims that ANCOVA is preferable if treatment assignment is based on randomization or on the pretest and questionable for preexisting groups. Some literature suggests that Lord's paradox has to do with measurement error in the pretest. This article shows two new things: First, the claims are confirmed by proving the mathematical equivalence of ANCOVA to a repeated measures model without group effect at pretest. Second, correction for measurement error in the pretest is shown to lead back to ANCOVA or to CHANGE, depending on the assumed absence or presence of a true group difference at pretest. These two new theoretical results are illustrated with multilevel (mixed) regression and structural equation modeling of data from two studies.

Visual Communications: Bridging Across Cultures. Selected Readings from the Annual Conference of the International Visual Literacy Association (23rd, Washington, D.C., October 1991).

ERIC Educational Resources Information Center

Baca, Judy Clark, Ed.; And Others

This book of readings consists of selected papers presented under five topics: (1) Research and Theory--18 papers including research on visual effects on attitude and cognition, students of different field dependence levels, modern and postmodern design on reader perceptions of news, effects of gray shades, short-term memory capacity differences,…

Changes in aspects of social functioning depend upon prior changes in neurodisability in people with acquired brain injury undergoing post-acute neurorehabilitation.

PubMed

Fortune, Dónal G; Walsh, R Stephen; Waldron, Brian; McGrath, Caroline; Harte, Maurice; Casey, Sarah; McClean, Brian

2015-01-01

Post-acute community-based rehabilitation is effective in reducing disability. However, while social participation and quality of life are valued as distal outcomes of neurorehabilitation, it is often not possible to observe improvements on these outcomes within the limited time-frames used in most investigations of rehabilitation. The aim of the current study was to examine differences in the sequence of attainments for people with acquired brain injury (ABI) undergoing longer term post-acute neurorehabilitation. Participants with ABI who were referred to comprehensive home and community-based neurorehabilitation were assessed at induction to service, at 6 months and again at 1.5 years while still in service on the Mayo-Portland Adaptability Index (MPAI-4), Community Integration Questionnaire, Hospital Anxiety and Depression Scale, and World Health Organisation Quality of Life measure. At 6 months post-induction to service, significant differences were evident in MPAI abilities, adjustment, and total neurodisability; and in anxiety and depression. By contrast, there was no significant effect at 6 months on more socially oriented features of experience namely quality of life (QoL), Community Integration and Participation. Eighteen month follow-up showed continuation of the significant positive effects with the addition of QoL-related to physical health, Psychological health, Social aspects of QoL and Participation at this later time point. Regression analyses demonstrated that change in QoL and Participation were dependent upon prior changes in aspects of neurodisability. Age, severity or type of brain injury did not significantly affect outcome. Results suggest that different constructs may respond to neurorehabilitation at different time points in a dose effect manner, and that change in social aspects of experience may be dependent upon the specific nature of prior neurorehabilitation attainments.

Evaluation of the dependence of the exposure dose on the attenuation correction in brain PET/CT scans using 18F-FDG

NASA Astrophysics Data System (ADS)

Choi, Eun-Jin; Jeong, Moon-Taeg; Jang, Seong-Joo; Choi, Nam-Gil; Han, Jae-Bok; Yang, Nam-Hee; Dong, Kyung-Rae; Chung, Woon-Kwan; Lee, Yun-Jong; Ryu, Young-Hwan; Choi, Sung-Hyun; Seong, Kyeong-Jeong

2014-01-01

This study examined whether scanning could be performed with minimum dose and minimum exposure to the patient after an attenuation correction. A Hoffman 3D Brain Phantom was used in BIO_40 and D_690 PET/CT scanners, and the CT dose for the equipment was classified as a low dose (minimum dose), medium dose (general dose for scanning) and high dose (dose with use of contrast medium) before obtaining the image at a fixed kilo-voltage-peak (kVp) and milliampere (mA) that were adjusted gradually in 17-20 stages. A PET image was then obtained to perform an attenuation correction based on an attenuation map before analyzing the dose difference. Depending on tube current in the range of 33-190 milliampere-second (mAs) when BIO_40 was used, a significant difference in the effective dose was observed between the minimum and the maximum mAs (p < 0.05). According to a Scheffe post-hoc test, the ratio of the minimum to the maximum of the effective dose was increased by approximately 5.26-fold. Depending on the change in the tube current in the range of 10-200 mA when D_690 was used, a significant difference in the effective dose was observed between the minimum and the maximum of mA (p < 0.05). The Scheffe posthoc test revealed a 20.5-fold difference. In conclusion, because effective exposure dose increases with increasing operating current, it is possible to reduce the exposure limit in a brain scan can be reduced if the CT dose can be minimized for a transmission scan.

Changes in aspects of social functioning depend upon prior changes in neurodisability in people with acquired brain injury undergoing post-acute neurorehabilitation

PubMed Central

Fortune, Dónal G.; Walsh, R. Stephen; Waldron, Brian; McGrath, Caroline; Harte, Maurice; Casey, Sarah; McClean, Brian

2015-01-01

Post-acute community-based rehabilitation is effective in reducing disability. However, while social participation and quality of life are valued as distal outcomes of neurorehabilitation, it is often not possible to observe improvements on these outcomes within the limited time-frames used in most investigations of rehabilitation. The aim of the current study was to examine differences in the sequence of attainments for people with acquired brain injury (ABI) undergoing longer term post-acute neurorehabilitation. Participants with ABI who were referred to comprehensive home and community-based neurorehabilitation were assessed at induction to service, at 6 months and again at 1.5 years while still in service on the Mayo-Portland Adaptability Index (MPAI-4), Community Integration Questionnaire, Hospital Anxiety and Depression Scale, and World Health Organisation Quality of Life measure. At 6 months post-induction to service, significant differences were evident in MPAI abilities, adjustment, and total neurodisability; and in anxiety and depression. By contrast, there was no significant effect at 6 months on more socially oriented features of experience namely quality of life (QoL), Community Integration and Participation. Eighteen month follow-up showed continuation of the significant positive effects with the addition of QoL-related to physical health, Psychological health, Social aspects of QoL and Participation at this later time point. Regression analyses demonstrated that change in QoL and Participation were dependent upon prior changes in aspects of neurodisability. Age, severity or type of brain injury did not significantly affect outcome. Results suggest that different constructs may respond to neurorehabilitation at different time points in a dose effect manner, and that change in social aspects of experience may be dependent upon the specific nature of prior neurorehabilitation attainments. PMID:26441744

Macroalgal Composition Determines the Structure of Benthic Assemblages Colonizing Fragmented Habitats.

PubMed

Matias, Miguel G; Arenas, Francisco; Rubal, Marcos; Pinto, Isabel S

2015-01-01

Understanding the consequences of fragmentation of coastal habitats is an important topic of discussion in marine ecology. Research on the effects of fragmentation has revealed complex and context-dependent biotic responses, which prevent generalizations across different habitats or study organisms. The effects of fragmentation in marine environments have been rarely investigated across heterogeneous habitats, since most studies have focused on a single type of habitat or patch. In this study, we assessed the effects of different levels of fragmentation (i.e. decreasing size of patches without overall habitat loss). We measured these effects using assemblages of macro-invertebrates colonizing representative morphological groups of intertidal macroalgae (e.g. encrusting, turf and canopy-forming algae). For this purpose, we constructed artificial assemblages with different combinations of morphological groups and increasing levels of fragmentation by manipulating the amount of bare rock or the spatial arrangement of different species in mixed assemblages. In general, our results showed that 1) fragmentation did not significantly affect the assemblages of macroinvertebrates; 2) at greater levels of fragmentation, there were greater numbers of species in mixed algal assemblages, suggesting that higher habitat complexity promotes species colonization. Our results suggest that predicting the consequences of fragmentation in heterogeneous habitats is dependent on the type and diversity of morphological groups making up those habitats.

Macroalgal Composition Determines the Structure of Benthic Assemblages Colonizing Fragmented Habitats

PubMed Central

Matias, Miguel G.; Arenas, Francisco; Rubal, Marcos; Pinto, Isabel S.

2015-01-01

Understanding the consequences of fragmentation of coastal habitats is an important topic of discussion in marine ecology. Research on the effects of fragmentation has revealed complex and context-dependent biotic responses, which prevent generalizations across different habitats or study organisms. The effects of fragmentation in marine environments have been rarely investigated across heterogeneous habitats, since most studies have focused on a single type of habitat or patch. In this study, we assessed the effects of different levels of fragmentation (i.e. decreasing size of patches without overall habitat loss). We measured these effects using assemblages of macro-invertebrates colonizing representative morphological groups of intertidal macroalgae (e.g. encrusting, turf and canopy-forming algae). For this purpose, we constructed artificial assemblages with different combinations of morphological groups and increasing levels of fragmentation by manipulating the amount of bare rock or the spatial arrangement of different species in mixed assemblages. In general, our results showed that 1) fragmentation did not significantly affect the assemblages of macroinvertebrates; 2) at greater levels of fragmentation, there were greater numbers of species in mixed algal assemblages, suggesting that higher habitat complexity promotes species colonization. Our results suggest that predicting the consequences of fragmentation in heterogeneous habitats is dependent on the type and diversity of morphological groups making up those habitats. PMID:26554924

Analysis of Histone Deacetylase-Dependent Effects on Cell Migration Using the Stripe Assay.

PubMed

Mertsch, Sonja; Thanos, Solon

2017-01-01

For normal embryonic development/morphogenesis, cell migration and homing are well-orchestrated and important events requiring specific cellular mechanisms. In diseases such as cancer deregulated cell migration represents a major problem. Therefore, numerous efforts are under way to understand the molecular mechanisms of tumor cell migration and to generate more efficient tumor therapies. Cell migration assays are one of the most commonly used functional assays. The wound-healing assay or the Boyden chamber assay are variations of these assays. Nearly all of them are two-dimensional assays and the cells can only migrate on one substrate at a time. This is in contrast to the in vivo situation where the cells are faced simultaneously with different surfaces and interact with different cell types. To approach this in vivo situation we used a modified version of the stripe assay designed by Bonhoeffer and colleagues to examine mechanisms of axonal guidance. The design of this assay allows cells to decide between two different substrates offered at the same time. Utilizing alternating neuronal substrates for migration analyses we can partially mimic the complex in vivo situation for brain tumor cells. Here we describe the detailed protocol to perform a modified version of the stripe assay in order to observe substrate-dependent migration effects in vitro, to analyze the effect of Rho-dependent kinases (ROCKS), of histone deacetylases (HDACs) and of other molecules on glioma cells.

The cognitive style of nursing students: educational implications for teaching and learning.

PubMed

Noble, Kim A; Miller, Susan M; Heckman, James

2008-06-01

As cognitive and kinesthetic demands on nursing students increase, so does the need for optimal learning environments. Witkin's empirically supported measure of field dependent/independent cognitive style assesses the manner in which students perceive and process information and classifies them along a continuum of field dependence to field independence. Witkin's Groups Embedded Figures Test (GEFT) was administered to 876 students enrolled in 10 health care programs. Statistically significant differences in the GEFT mean scores of students enrolled in the different programs were discovered. The effect size was moderate. Undergraduate nursing students scored higher on the GEFT than did graduate or RN-to-BSN nursing students. However, nursing students were classified as more field dependent than students in other health-related disciplines. Due to their cognitive processing requirements, field-dependent nursing students may be at risk for academic failure. Therefore, instructional strategies tailored to students' needs should be incorporated into the nursing curriculum.

The Faraday effect of natural and artificial ferritins.

PubMed

Koralewski, M; Kłos, J W; Baranowski, M; Mitróová, Z; Kopčanský, P; Melníková, L; Okuda, M; Schwarzacher, W

2012-09-07

Measurements of the Faraday rotation at room temperature over the light wavelength range of 300-680 nm for horse spleen ferritin (HSF), magnetoferritin with different loading factors (LFs) and nanoscale magnetite and Fe(2)O(3) suspensions are reported. The Faraday rotation and the magnetization of the materials studied present similar magnetic field dependences and are characteristic of a superparamagnetic system. The dependence of the Faraday rotation on the magnetic field is described, excluding HSF and Fe(2)O(3), by a Langevin function with a log-normal distribution of the particle size allowing the core diameters of the substances studied to be calculated. It was found that the specific Verdet constant depends linearly on the LF. Differences in the Faraday rotation spectra and their magnetic field dependences allow discrimination between magnetoferritin with maghemite and magnetite cores which can be very useful in biomedicine.

Effects of Sublethal Exposure to a Glyphosate-Based Herbicide Formulation on Metabolic Activities of Different Xenobiotic-Metabolizing Enzymes in Rats.

PubMed

Larsen, Karen; Najle, Roberto; Lifschitz, Adrián; Maté, María L; Lanusse, Carlos; Virkel, Guillermo L

2014-07-01

The activities of different xenobiotic-metabolizing enzymes in liver subcellular fractions from Wistar rats exposed to a glyphosate (GLP)-based herbicide (Roundup full II) were evaluated in this work. Exposure to the herbicide triggered protective mechanisms against oxidative stress (increased glutathione peroxidase activity and total glutathione levels). Liver microsomes from both male and female rats exposed to the herbicide had lower (45%-54%, P < 0.01) hepatic cytochrome P450 (CYP) levels compared to their respective control animals. In female rats, the hepatic 7-ethoxycoumarin O-deethylase (a general CYP-dependent enzyme activity) was 57% higher (P < 0.05) in herbicide-exposed compared to control animals. Conversely, this enzyme activity was 58% lower (P < 0.05) in male rats receiving the herbicide. Lower (P < 0.05) 7-ethoxyresorufin O-deethlyase (EROD, CYP1A1/2 dependent) and oleandomycin triacetate (TAO) N-demethylase (CYP3A dependent) enzyme activities were observed in liver microsomes from exposed male rats. Conversely, in females receiving the herbicide, EROD increased (123%-168%, P < 0.05), whereas TAO N-demethylase did not change. A higher (158%-179%, P < 0.01) benzyloxyresorufin O-debenzylase (a CYP2B-dependent enzyme activity) activity was only observed in herbicide-exposed female rats. In herbicide-exposed rats, the hepatic S-oxidation of methimazole (flavin monooxygenase dependent) was 49% to 62% lower (P < 0.001), whereas the carbonyl reduction of menadione (a cytosolic carbonyl reductase-dependent activity) was higher (P < 0.05). Exposure to the herbicide had no effects on enzymatic activities dependent on carboxylesterases, glutathione transferases, and uridinediphospho-glucuronosyltransferases. This research demonstrated certain biochemical modifications after exposure to a GLP-based herbicide. Such modifications may affect the metabolic fate of different endobiotic and xenobiotic substances. The pharmacotoxicological significance of these findings remains to be clarified. © The Author(s) 2014.

When Does Provision of Instruction Promote Learning?

ERIC Educational Resources Information Center

Lee, Hee Seung; Anderson, Abraham; Betts, Shawn; Anderson, John R.

2011-01-01

Contradictory evidence has been reported on the effects of discovery learning approach and the role of instructional explanations. By manipulating the presence of instruction (verbal explanation) and transparency of problem structures, we investigated how effects of instructional explanations differed depending on the transparency of problem…

Effects of problem-based learning by learning style in medical education.

PubMed

Chae, Su-Jin

2012-12-01

Although problem-based learning (PBL) has been popularized in many colleges, few studies have analyzed the relationship between individual differences and PBL. The purpose of this study was to analyze the relationship between learning style and the perception on the effects of PBL. Grasha-Riechmann Student Learning Style Scales was used to assess the learning styles of 38 students at Ajou University School of Medicine who were enrolled in a respiratory system course in 2011. The data were analyzed by regression analysis and Spearman correlation analysis. By regression analysis, dependent beta=0.478) and avoidant styles (beta=-0.815) influenced the learner's satisfaction with PBL. By Spearman correlation analysis, there was significant link between independent, dependent, and avoidant styles and the perception of the effect of PBL. There are few significant relationships between learning style and the perception of the effects of PBL. We must determine how to teach students with different learning styles and the factors that influence PBL.

The effects of habitat connectivity and regional heterogeneity on artificial pond metacommunities.

PubMed

Pedruski, Michael T; Arnott, Shelley E

2011-05-01

Habitat connectivity and regional heterogeneity represent two factors likely to affect biodiversity across different spatial scales. We performed a 3 × 2 factorial design experiment to investigate the effects of connectivity, heterogeneity, and their interaction on artificial pond communities of freshwater invertebrates at the local (α), among-community (β), and regional (γ) scales. Despite expectations that the effects of connectivity would depend on levels of regional heterogeneity, no significant interactions were found for any diversity index investigated at any spatial scale. While observed responses of biodiversity to connectivity and heterogeneity depended to some extent on the diversity index and spatial partitioning formula used, the general pattern shows that these factors largely act at the β scale, as opposed to the α or γ scales. We conclude that the major role of connectivity in aquatic invertebrate communities is to act as a homogenizing force with relatively little effect on diversity at the α or γ levels. Conversely, heterogeneity acts as a force maintaining differences between communities.

Comparison of striatal dopamine transporter levels in chronic heroin-dependent and methamphetamine-dependent subjects.

PubMed

Yuan, Jie; Liu, Xing Dang; Han, Mei; Lv, Rong Bin; Wang, Yuan Kai; Zhang, Guang Ming; Li, Yu

2017-01-01

To compare the effects of heroin and methamphetamine (METH) addiction on dopamine transporters (DATs) in the same dose and duration, we assessed DAT levels in the striatum by 99m Tc-TRODAT-1 single-photon emission computed tomography (SPECT) brain images in people with heroin and METH dependence. We recruited 21 healthy human controls, 23 heroin-dependent subjects and 25 METH abusers. The heroin- and METH-dependent subjects exhibited negative urine toxicology after undergoing physiological detoxification. All subjects underwent SPECT brain imaging, and specific tracer uptake ratios (SURs) were assessed bilaterally in the regions of interest. A significant SUR reduction in heroin-dependent subjects and METH-dependent subjects compared with healthy controls was found in the left striatum, right striatum, left caudate nucleus, right caudate nucleus, left putamen and right putamen. There were no significant differences in the heroin group and METH group for the left striatum, right striatum, left caudate nucleus, right caudate nucleus, left putamen and right putamen. The scores of craving, HAMA (Hamilton Anxiety Rating Scale), in heroin abusers were lower than in the METH abusers. Our results show that people with heroin and METH dependence who are currently abstinent had lower DAT levels in the striatum than healthy controls. There were no differences in striatal DAT in heroin and METH users. These results suggest that chronic heroin and METH abuse appears to produce similar effects in striatal DAT in humans. METH users may have more serious craving and anxiety symptoms than heroin users with prolonged abstinence. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Effects of heavy ion to the primary culture of mouse brain cells

NASA Technical Reports Server (NTRS)

Nojima, Kumie; Nakadai, Taeko; Kohno, Yukio; Vazquez, Marcelo E.; Yasuda, Nakahiro; Nagaoka, Shunji

2004-01-01

To investigate effects of low dose heavy particle radiation to CNS system, we adopted mouse neonatal brain cells in culture being exposed to heavy ions by HIMAC at NIRS and NSRL at BNL. The applied dose varied from 0.05 Gy up to 2.0 Gy. The subsequent biological effects were evaluated by an induction of apoptosis and neuron survival focusing on the dependencies of the animal strains, SCID, B6, B6C3F1, C3H, used for brain cell culture, SCID was the most sensitive and C3H the least sensitive to particle radiation as evaluated by 10% apoptotic criterion. The LET dependency was compared with using SCID and B6 cells exposing to different ions (H, C, Ne, Si, Ar, and Fe). Although no detectable LET dependency was observed in the high LET (55-200 keV/micrometers) and low dose (<0.5 Gy) regions. The survivability profiles of the neurons were different in the mouse strains and ions. In this report, a result of memory and learning function to adult mice after whole-body and brain local irradiation at carbon ion and iron ion.

Influence of buffer-layer construction and substrate orientation on the electron mobilities in metamorphic In{sup 0.70}Al{sup 0.30}As/In{sup 0.76}Ga{sup 0.24}As/In{sup 0.70}Al{sup 0.30}As structures on GaAs substrates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kulbachinskii, V. A., E-mail: kulb@mig.phys.msu.ru; Oveshnikov, L. N.; Lunin, R. A.

The influence of construction of the buffer layer and misorientation of the substrate on the electrical properties of In{sup 0.70}Al{sup 0.30}As/In{sup 0.76}Ga{sup 0.24}As/In{sup 0.70}Al{sup 0.30}As quantum wells on a GaAs substrate is studied. The temperature dependences (in the temperature range of 4.2 K < T < 300 K) and field dependences (in magnetic fields as high as 6 T) of the sample resistances are measured. Anisotropy of the resistances in different crystallographic directions is detected; this anisotropy depends on the substrate orientation and construction of the metamorphic buffer layer. In addition, the Hall effect and the Shubnikov–de Haas effect aremore » studied. The Shubnikov–de Haas effect is used to determine the mobilities of electrons separately in several occupied dimensionally quantized subbands in different crystallographic directions. The calculated anisotropy of mobilities is in agreement with experimental data on the anisotropy of the resistances.« less

Causal beliefs of the public and social acceptance of persons with mental illness: a comparative analysis of schizophrenia, depression and alcohol dependence.

PubMed

Schomerus, G; Matschinger, H; Angermeyer, M C

2014-01-01

There is an ongoing debate whether biological illness explanations improve tolerance towards persons with mental illness or not. Several theoretical models have been proposed to predict the relationship between causal beliefs and social acceptance. This study uses path models to compare different theoretical predictions regarding attitudes towards persons with schizophrenia, depression and alcohol dependence. In a representative population survey in Germany (n = 3642), we elicited agreement with belief in biogenetic causes, current stress and childhood adversities as causes of either disorder as described in an unlabelled case vignette. We further elicited potentially mediating attitudes related to different theories about the consequences of biogenetic causal beliefs (attribution theory: onset responsibility, offset responsibility; genetic essentialism: differentness, dangerousness; genetic optimism: treatability) and social acceptance. For each vignette condition, we calculated a multiple mediator path model containing all variables. Biogenetic beliefs were associated with lower social acceptance in schizophrenia and depression, and with higher acceptance in alcohol dependence. In schizophrenia and depression, perceived differentness and dangerousness mediated the largest indirect effects, the consequences of biogenetic causal explanations thus being in accordance with the predictions of genetic essentialism. Psychosocial causal beliefs had differential effects: belief in current stress as a cause was associated with higher acceptance in schizophrenia, while belief in childhood adversities resulted in lower acceptance of a person with depression. Biological causal explanations seem beneficial in alcohol dependence, but harmful in schizophrenia and depression. The negative correlates of believing in childhood adversities as a cause of depression merit further exploration.

Cisplatin-induced cytotoxicity in BSO-exposed renal proximal tubular epithelial cells: sex, age, and species.

PubMed

Lu, Yongke; Kawashima, Akira; Horii, Ikuo; Zhong, Laifu

2005-01-01

Cisplatin (CP)-induced kidney damage and effects of DL-buthionine-(S,R)-sulfoximine (BSO) on it are species- and age-different. It remains unclear whether CP-induced cytotoxicity in renal proximal tubular epithelial cells (RTEC), the main target cells of CP, is also species- and age-different; and whether CP-induced cytotoxicity varies with the difference in age and species, if any, is one of the questions. In the present study, the effects of BSO on CP-induced cytotoxicity in primary cultures of RTEC isolated from monkeys and different age and sex rats were studied. The RTEC were isolated from 3-week-old, 2-month-old, or 5-month-old rats, and 6-8 year-old monkeys. After subculturing, RTEC was inoculated into type I collagen-coated 96-well culture plates; after preincubation, 40 microM BSO was added, 16 hours later, varying concentrations of CP were added. At that time, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assays were performed to test cell viability. The concentrations of CP that inhibited 50% cell growth (IC50) of RTEC from rats and monkeys were 1.11 and 3.03 mM at 8 hours, and 0.51 and 1.24 mM at 24 hours, respectively. The BSO made the IC50s of RTEC from rats and monkeys lower, down to 0.07 and 0.48 mM at 8 hours, and 0.02 and 0.11 mM at 24 hours, respectively. The IC50s of RTEC from different sex and age rats were almost same. These results suggested that CP-induced cytotoxicity was concentration- and time-dependent, with species-dependent differences, rat RTEC were more susceptible to CP than monkey RTEC, rat RTEC were more dependent on glutathione (GSH) during the stress state were than monkey cells; CP-induced cytotoxicity was without sex- and age-dependent differences in rat RTEC.

Solvent effects in time-dependent self-consistent field methods. I. Optical response calculations

DOE PAGES

Bjorgaard, J. A.; Kuzmenko, V.; Velizhanin, K. A.; ...

2015-01-22

In this study, we implement and examine three excited state solvent models in time-dependent self-consistent field methods using a consistent formalism which unambiguously shows their relationship. These are the linear response, state specific, and vertical excitation solvent models. Their effects on energies calculated with the equivalent of COSMO/CIS/AM1 are given for a set of test molecules with varying excited state charge transfer character. The resulting solvent effects are explained qualitatively using a dipole approximation. It is shown that the fundamental differences between these solvent models are reflected by the character of the calculated excitations.

Height Dependency of Aerosol-Cloud Interaction Regimes: Height Dependency of ACI Regime

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Jingyi; Liu, Yangang; Zhang, Minghua

This study investigates the height dependency of aerosol-cloud interaction regimes in terms of the joint dependence of the key cloud microphysical properties (e.g. cloud droplet number concentration, cloud droplet relative dispersion, etc.) on aerosol number concentration (N a) and vertical velocity (w). The three distinct regimes with different microphysical features are the aerosol-limited regime, the updraft-limited regime, and the transitional regime. The results reveal two new phenomena in updraft-limited regime: 1) The “condensational broadening” of cloud droplet size distribution in contrast to the well-known “condensational narrowing” in the aerosol-limited regime; 2) Above the level of maximum supersaturation, some cloud dropletsmore » are deactivated into interstitial aerosols in the updraft-limited regime whereas all droplets remain activated in the aerosol-limited regime. Further analysis shows that the particle equilibrium supersaturation plays important role in understanding these unique features. Also examined is the height of warm rain initiation and its dependence on N a and w. The rain initiation height is found to depend primarily on either N a or w or both in different N a-w regimes, thus suggesting a strong regime dependence of the second aerosol indirect effect.« less

Height Dependency of Aerosol-Cloud Interaction Regimes: Height Dependency of ACI Regime

DOE PAGES

Chen, Jingyi; Liu, Yangang; Zhang, Minghua; ...

2018-01-10

This study investigates the height dependency of aerosol-cloud interaction regimes in terms of the joint dependence of the key cloud microphysical properties (e.g. cloud droplet number concentration, cloud droplet relative dispersion, etc.) on aerosol number concentration (N a) and vertical velocity (w). The three distinct regimes with different microphysical features are the aerosol-limited regime, the updraft-limited regime, and the transitional regime. The results reveal two new phenomena in updraft-limited regime: 1) The “condensational broadening” of cloud droplet size distribution in contrast to the well-known “condensational narrowing” in the aerosol-limited regime; 2) Above the level of maximum supersaturation, some cloud dropletsmore » are deactivated into interstitial aerosols in the updraft-limited regime whereas all droplets remain activated in the aerosol-limited regime. Further analysis shows that the particle equilibrium supersaturation plays important role in understanding these unique features. Also examined is the height of warm rain initiation and its dependence on N a and w. The rain initiation height is found to depend primarily on either N a or w or both in different N a-w regimes, thus suggesting a strong regime dependence of the second aerosol indirect effect.« less

Cross-Dependency Inference in Multi-Layered Networks: A Collaborative Filtering Perspective.

PubMed

Chen, Chen; Tong, Hanghang; Xie, Lei; Ying, Lei; He, Qing

2017-08-01

The increasingly connected world has catalyzed the fusion of networks from different domains, which facilitates the emergence of a new network model-multi-layered networks. Examples of such kind of network systems include critical infrastructure networks, biological systems, organization-level collaborations, cross-platform e-commerce, and so forth. One crucial structure that distances multi-layered network from other network models is its cross-layer dependency, which describes the associations between the nodes from different layers. Needless to say, the cross-layer dependency in the network plays an essential role in many data mining applications like system robustness analysis and complex network control. However, it remains a daunting task to know the exact dependency relationships due to noise, limited accessibility, and so forth. In this article, we tackle the cross-layer dependency inference problem by modeling it as a collective collaborative filtering problem. Based on this idea, we propose an effective algorithm Fascinate that can reveal unobserved dependencies with linear complexity. Moreover, we derive Fascinate-ZERO, an online variant of Fascinate that can respond to a newly added node timely by checking its neighborhood dependencies. We perform extensive evaluations on real datasets to substantiate the superiority of our proposed approaches.

Motives for using: a comparison of prescription opioid, marijuana and cocaine dependent individuals.

PubMed

Hartwell, Karen J; Back, Sudie E; McRae-Clark, Aimee L; Shaftman, Stephanie R; Brady, Kathleen T

2012-04-01

Identification of the motives for drug use is critical to the development of effective interventions. Furthermore, consideration of the differences in motives for drug use across substance dependent populations may assist in tailoring interventions. To date, few studies have systematically compared motives for substance use across drug classes. The current study examined motives for drug use between non-treatment seeking individuals with current prescription opioid, marijuana, or cocaine dependence. Participants (N=227) completed the Inventory of Drug-Taking Situations (IDTS; Annis, Turner & Sklar,1997), which contains eight subscales assessing motives for drug use. The findings revealed that prescription opioid dependent individuals scored significantly higher than all other groups on the Physical Discomfort, Testing Personal Control and Conflict with Others subscales. Both the prescription opioid and cocaine dependent groups scored significantly higher than the marijuana group on the Urges or a Temptation to Use subscale. In contrast, marijuana dependent individuals scored highest on the Pleasant Emotions and Pleasant Times with Others subscales. The marked differences revealed in motives for drug use could be used in the development and implementation of specific treatment interventions for prescription opioid, marijuana and cocaine dependent individuals. Published by Elsevier Ltd.

Emotional Intelligence Components in Alcohol Dependent and Mentally Healthy Individuals

PubMed Central

Mohagheghi, Arash; Amiri, Shahrokh; Mousavi Rizi, Seyedreza; Safikhanlou, Salman

2015-01-01

Objective. Emotional intelligence might play an important role in the onset and persistence of different psychopathologies. This study investigated the relationship between emotional intelligence and alcohol dependence. Methods. In this case-control study, participants included alcohol dependent individuals and mentally healthy inpatients. Each group consisted of 40 individuals (male/female: 1). The diagnosis was based on the criteria of the DSM-IV-TR using the Structured Clinical Interview for DSM-IV (SCID-IV). All the participants completed Bar-On emotional intelligence test. Results. 20 males and 20 females were included in each group. Mean age of alcohol dependent participants and controls was 31.28 ± 7.82 and 34.93 ± 9.83 years in that order. The analyses showed that the alcohol dependent individuals had a significant difference compared with the control group and received lower scores in empathy, responsibility, impulse control, self-esteem, optimism, emotional consciousness, stress tolerance, autonomy, problem-solving, and total score of emotional intelligence components. Conclusion. Patients with alcohol dependence have deficits in components of emotional intelligence. Identifying and targeted training of the individuals with lower scores in components of emotional intelligence may be effective in prevention of alcohol dependence. PMID:25893214

Emotional intelligence components in alcohol dependent and mentally healthy individuals.

PubMed

Mohagheghi, Arash; Amiri, Shahrokh; Mousavi Rizi, Seyedreza; Safikhanlou, Salman

2015-01-01

Emotional intelligence might play an important role in the onset and persistence of different psychopathologies. This study investigated the relationship between emotional intelligence and alcohol dependence. In this case-control study, participants included alcohol dependent individuals and mentally healthy inpatients. Each group consisted of 40 individuals (male/female: 1). The diagnosis was based on the criteria of the DSM-IV-TR using the Structured Clinical Interview for DSM-IV (SCID-IV). All the participants completed Bar-On emotional intelligence test. 20 males and 20 females were included in each group. Mean age of alcohol dependent participants and controls was 31.28±7.82 and 34.93±9.83 years in that order. The analyses showed that the alcohol dependent individuals had a significant difference compared with the control group and received lower scores in empathy, responsibility, impulse control, self-esteem, optimism, emotional consciousness, stress tolerance, autonomy, problem-solving, and total score of emotional intelligence components. Patients with alcohol dependence have deficits in components of emotional intelligence. Identifying and targeted training of the individuals with lower scores in components of emotional intelligence may be effective in prevention of alcohol dependence.

Motor impairment: a new ethanol withdrawal phenotype in mice

PubMed Central

Philibin, Scott D.; Cameron, Andy J.; Metten, Pamela; Crabbe, John C.

2015-01-01

Alcoholism is a complex disorder with genetic and environmental risk factors. The presence of withdrawal symptoms is one criterion for alcohol dependence. Genetic animal models have followed a reductionist approach by quantifying various effects of ethanol withdrawal separately. Different ethanol withdrawal symptoms may have distinct genetic etiologies, and therefore differentiating distinct neurobiological mechanisms related to separate signs of withdrawal would increase our understanding of various aspects of the complex phenotype. This study establishes motor incoordination as a new phenotype of alcohol withdrawal in mice. Mice were made physically dependent on ethanol by exposure to ethanol vapor for 72 h. The effects of ethanol withdrawal in mice from different genetic backgrounds were measured on the accelerating rotarod, a simple motor task. Ethanol withdrawal disrupted accelerating rotarod behavior in mice. The disruptive effects of withdrawal suggest a performance rather than a learning deficit. Inbred strain comparisons suggest genetic differences in magnitude of this withdrawal phenotype. The withdrawal-induced deficits were not correlated with the selection response difference in handling convulsion severity in selectively bred Withdrawal Seizure-Prone and Withdrawal Seizure-Resistant lines. The accelerating rotarod seems to be a simple behavioral measure of ethanol withdrawal that is suitable for comparing genotypes. PMID:18690115

Harmful impact on presynaptic glutamate and GABA transport by carbon dots synthesized from sulfur-containing carbohydrate precursor.

PubMed

Borisova, Tatiana; Dekaliuk, Mariia; Pozdnyakova, Natalia; Pastukhov, Artem; Dudarenko, Marina; Borysov, Arsenii; Vari, Sandor G; Demchenko, Alexander P

2017-07-01

Carbon nanoparticles that may be potent air pollutants with adverse effects on human health often contain heteroatoms including sulfur. In order to study in detail their effects on different physiological and biochemical processes, artificially produced carbon dots (CDs) with well-controlled composition that allows fluorescence detection may be of great use. Having been prepared from different types of organic precursors, CDs expose different atoms at their surface suggesting a broad variation of functional groups. Recently, we demonstrated neurotoxic properties of CDs synthesized from the amino acid β-alanine, and it is of importance to analyze whether CDs obtained from different precursors and particularly those exposing sulfur atoms induce similar neurotoxic effects. This study focused on synthesis of CDs from the sulfur-containing precursor thiourea-CDs (TU-CDs) with a size less than 10 nm, their characterization, and neuroactivity assessment. Neuroactive properties of TU-CDs were analyzed based on their effects on the key characteristics of glutamatergic and γ-aminobutyric acid (GABA) neurotransmission in isolated rat brain nerve terminals. It was observed that TU-CDs (0.5-1.0 mg/ml) attenuated the initial velocity of Na + -dependent transporter-mediated uptake and accumulation of L-[ 14 C]glutamate and [ 3 H]GABA by nerve terminals in a dose-dependent manner and increased the ambient level of the neurotransmitters. Starting from the concentration of 0.2 mg/ml, TU-CDs evoked a gradual dose-dependent depolarization of the plasma membrane of nerve terminals measured with the cationic potentiometric dye rhodamine 6G. Within the concentration range of 0.1-0.5 mg/ml, TU-CDs caused an "unphysiological" step-like increase in fluorescence intensity of the рН-sensitive fluorescent dye acridine orange accumulated by synaptic vesicles. Therefore, despite different surface properties and fluorescent features of CDs prepared from different starting materials (thiourea and β-alanine), their principal neurotoxic effects are analogous but displayed at a different level of efficiency. Sulfur-containing TU-CDs exhibit lower effects (by ~30%) on glutamate and GABA transport in the nerve terminals in comparison with sulfur-free β-alanine CDs. Our results suggest considering that an uncontrolled presence of carbon-containing particulate matter in the human environment may pose a toxicity risk for the central nervous system.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Siyao; Lazarian, A.; Yan, Huirong, E-mail: hryan@pku.edu.cn

We address the problem of the different line widths of coexistent neutrals and ions observed in molecular clouds and explore whether this difference can arise from the effects of magnetohydrodynamic (MHD) turbulence acting on partially ionized gas. Among the three fundamental modes of MHD turbulence, we find that fast and slow modes do not contribute to line width differences. We focus on the Alfvénic component, and consider the damping of Alfvén modes by taking into account both neutral-ion collisions and neutral viscosity. We confirm that the line width difference can be explained by the differential damping of the Alfvénic turbulencemore » in ions and the hydrodynamic turbulence in neutrals, and find it strongly depends on the properties of MHD turbulence. We consider various regimes of turbulence corresponding to different media magnetizations and turbulent drivings. In the case of super-Alfvénic turbulence, when the damping scale of Alfvénic turbulence is below the Alfvénic scale l{sub A}, the line width difference does not depend on magnetic field strength. In other turbulence regimes, however, the dependence is present and evaluation of magnetic field from the observed line width difference is possible.« less

Triggering collective oscillations by three-flavor effects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dasgupta, Basudeb; Raffelt, Georg G.; Tamborra, Irene

2010-04-01

Collective flavor transformations in supernovae, caused by neutrino-neutrino interactions, are essentially a two-flavor phenomenon driven by the atmospheric mass difference and the small mixing angle {theta}{sub 13}. In the two-flavor approximation, the initial evolution depends logarithmically on {theta}{sub 13} and the system remains trapped in an unstable fixed point for {theta}{sub 13}=0. However, any effect breaking exact {nu}{sub {mu}-{nu}{tau}}equivalence triggers the conversion. Such three-flavor perturbations include radiative corrections to weak interactions, small differences between the {nu}{sub {mu}}and {nu}{sub {tau}}fluxes, or nonstandard interactions. Therefore, extremely small values of {theta}{sub 13} are in practice equivalent, the fate of the system depending onlymore » on the neutrino spectra and their mass ordering.« less

Trapping photons on the line: controllable dynamics of a quantum walk

NASA Astrophysics Data System (ADS)

Xue, Peng; Qin, Hao; Tang, Bao

2014-04-01

Optical interferometers comprising birefringent-crystal beam displacers, wave plates, and phase shifters serve as stable devices for simulating quantum information processes such as heralded coined quantum walks. Quantum walks are important for quantum algorithms, universal quantum computing circuits, quantum transport in complex systems, and demonstrating intriguing nonlinear dynamical quantum phenomena. We introduce fully controllable polarization-independent phase shifters in optical pathes in order to realize site-dependent phase defects. The effectiveness of our interferometer is demonstrated through realizing single-photon quantum-walk dynamics in one dimension. By applying site-dependent phase defects, the translational symmetry of an ideal standard quantum walk is broken resulting in localization effect in a quantum walk architecture. The walk is realized for different site-dependent phase defects and coin settings, indicating the strength of localization signature depends on the level of phase due to site-dependent phase defects and coin settings and opening the way for the implementation of a quantum-walk-based algorithm.

Possible pore size effects on the state of tris(8-quinolinato)aluminum(III) (Alq3) adsorbed in mesoporous silicas and their temperature dependence.

PubMed

Tagaya, Motohiro; Ogawa, Makoto

2008-12-07

The states of tris(8-quinolinato)aluminum(III) (Alq3) adsorbed in mesoporous silicas with different pore sizes (2.5, 3.1 and 5.0 nm) were investigated. Alq3 was successfully occluded into the mesoporous silicas from solution and the adsorbed amount of Alq3 per BET surface area was effectively controlled by changing the added amount Alq3 to the solution. The state of Alq3 in the mesopore varied depending on the pore size as well as the adsorbed amount of Alq3 as revealed by variation of the photoluminescence spectra. The luminescence of the adsorbed Alq3 was found to be temperature-dependent, indicating the mobility of the adsorbed Alq3 to temperature variations. The temperature-dependence also depended on the pore size. The guest-guest interactions between Alq3 molecules as well as the host-guest interactions between Alq3 and the mesopore were controlled by the pore size.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vidal, Luciano N., E-mail: lnvidal@utfpr.edu.br; Cappelli, Chiara, E-mail: chiara.cappelli@unipi.it; Egidi, Franco

A theoretical investigation on the origin dependence of the vibronic polarizabilities, isotropic and anisotropic rotational invariants, and scattering cross sections in Resonance Raman Optical Activity (RROA) spectroscopy is presented. Expressions showing the origin dependence of these polarizabilities were written in the resonance regime using the Franck-Condon (FC) and Herzberg-Teller (HT) approximations for the electronic transition moments. Differently from the far-from-resonance scattering regime, where the origin dependent terms cancel out when the rotational invariants are calculated, RROA spectrum can exhibit some origin dependence even for eigenfunctions of the electronic Hamiltonian. At the FC level, the RROA spectrum is completely origin invariantmore » if the polarizabilities are calculated using a single excited state or for a set of degenerate states. Otherwise, some origin effects can be observed in the spectrum. At the HT level, RROA spectrum is origin dependent even when the polarizabilities are evaluated from a single excited state but the origin effect is expected to be small in this case. Numerical calculations performed for (S)-methyloxirane, (2R,3R)-dimethyloxirane, and (R)-4-F-2-azetidinone at both FC and HT levels using the velocity representation of the electric dipole and quadrupole transition moments confirm the predictions of the theory and show the extent of origin effects and the effectiveness of suggested ways to remove them.« less

Alcoholism risk moderation by a socio-religious dimension.

PubMed

Haber, Jon Randolph; Jacob, Theodore

2007-11-01

Religious affiliation is inversely associated with the development of alcohol-dependence symptoms in adolescents, but the mechanisms of this effect are unclear. The degree to which religious affiliations accommodate to or differentiate from cultural values may influence attitudes about alcohol use. We hypothesized that, given permissive cultural norms about alcohol in the United States, if a religious affiliation differentiates itself from cultural norms, then high-risk adolescents (those with parents having a history of alcoholism) would exhibit fewer alcohol-dependence symptoms compared with other affiliations and nonreligious adolescents. A sample of female adolescent offspring (N = 3,582) in Missouri was selected. Parental alcoholism and religious affiliation and their interaction were examined as predictors of offspring alcohol-dependence symptoms. Findings indicated that (1) parental alcohol history robustly predicted increased offspring alcohol-dependence symptoms, (2) religious rearing appeared protective (offspring exhibited fewer alcohol-dependence symptoms), (3) religious differentiation accounted for most of the protective effect, (4) other religious variables did not account for the differentiation effect, and (5) black religious adolescents were more frequently raised with differentiating affiliations and exhibited greater protective effects. Results demonstrate that religious differentiation accounts for most of the protective influence of religious affiliation. This may be because religious differences from cultural norms (that include permissive alcohol norms) counteract these social influences given alternative "higher" religious ideals.

Position and mode dependent optical detection back-action in cantilever beam resonators

NASA Astrophysics Data System (ADS)

Larsen, T.; Schmid, S.; Dohn, S.; Sader, J. E.; Boisen, A.; Villanueva, L. G.

2017-03-01

Optical detection back-action in cantilever resonant or static detection presents a challenge when striving for state-of-the-art performance. The origin and possible routes for minimizing optical back-action have received little attention in literature. Here, we investigate the position and mode dependent optical back-action on cantilever beam resonators. A high power heating laser (100 µW) is scanned across a silicon nitride cantilever while its effect on the first three resonance modes is detected via a low-power readout laser (1 µW) positioned at the cantilever tip. We find that the measured effect of back-action is not only dependent on position but also the shape of the resonance mode. Relevant silicon nitride material parameters are extracted by fitting finite element (FE) simulations to the temperature-dependent frequency response of the first three modes. In a second round of simulations, using the extracted parameters, we successfully fit the FEM results with the measured mode and position dependent back-action. From the simulations, we can conclude that the observed frequency tuning is due to temperature induced changes in stress. Effects of changes in material properties and dimensions are negligible. Finally, different routes for minimizing the effect of this optical detection back-action are described, allowing further improvements of cantilever-based sensing in general.

Sex differences in salt sensitivity to nitric oxide dependent vasodilation in healthy young adults

PubMed Central

Gullixson, Leah R.; Kost, Susan L.; Joyner, Michael J.; Turner, Stephen T.; Nicholson, Wayne T.

2012-01-01

Dietary sodium and blood pressure regulation differs between normotensive men and women, an effect which may involve endothelial production of nitric oxide (NO). Therefore, we tested the hypothesis that differences in the NO component of endothelium-dependent vasodilation between low and high dietary sodium intake depend on sex. For 5 days prior to study, healthy adults consumed a controlled low-sodium diet (10 mmol/day, n = 30, mean age ± SE: 30 ± 1 yr, 16 men) or high-sodium diet (400 mmol/day, n = 36, age 23 ± 1 yr, 13 men). Forearm blood flow (FBF, plethysmography) responses to brachial artery administration of acetylcholine (ACh, 4 μg·100 ml tissue−1·min−1) were measured before and after endothelial NO synthase inhibition with NG-monomethyl-l-arginine (l-NMMA, 50 mg bolus + 1 mg/min infusion). The NO component of endothelium-dependent dilation was calculated as the response to ACh before and after l-NMMA accounting for changes in baseline FBF: [(FBF ACh − FBF baseline) − (FBF AChL-NMMA − FBF baselineL-NMMA)]. This value was 5.7 ± 1.3 and 2.5 ± 0.8 ml·100 ml forearm tissue−1·min−1 for the low- and high-sodium diets, respectively (main effect of sodium, P = 0.019). The sodium effect was larger for the men, with values of 7.9 ± 2.0 and 2.2 ± 1.4 for men vs. 3.1 ± 1.3 and 2.7 ± 1.0 ml·100 ml forearm tissue−1·min−1 for the women (P = 0.034, sex-by-sodium interaction). We conclude that the NO component of endothelium-dependent vasodilation is altered by dietary sodium intake based on sex, suggesting that endothelial NO production is sensitive to dietary sodium in healthy young men but not women. PMID:22194324

Core-dependent and ligand-dependent relativistic corrections to the nuclear magnetic shieldings in MH4-n Y n (n = 0-4; M = Si, Ge, Sn, and Y = H, F, Cl, Br, I) model compounds.

PubMed

Maldonado, Alejandro F; Aucar, Gustavo A; Melo, Juan I

2014-09-01

The nuclear magnetic shieldings of Si, Ge, and Sn in MH(4-n) Y(n) (M = Si, Ge, Sn; Y = F, Cl, Br, I and n = 1-4) molecular systems are highly influenced by the substitution of one or more hydrogens by heavy-halogen atoms. We applied the linear response elimination of small components (LRESC) formalism to calculate those shieldings and learn whether including only a few of the leading relativistic correction terms is sufficient to be able to quantitatively reproduce the full relativistic value. It was observed that the nuclear magnetic shieldings change as the number of heavy halogen substituents and their weights vary, and the pattern of σ(M) generally does not exhibit the normal halogen dependence (NHD) behavior that can be seen in similar molecular systems containing carbon atoms. We also analyzed each relativistic correction afforded by the LRESC method and split them in two: core-dependent and ligand-dependent contributions; we then looked for the electronic mechanisms involved in the different relativistic effects and in the total relativistic value. Based on this analysis, we were able to study the electronic mechanism involved in a recently proposed relativistic effect, the "heavy atom effect on vicinal heavy atom" (HAVHA), in more detail. We found that the main electronic mechanism is the spin-orbit or σ p (T(3)) correction, although other corrections such as σ p (S(1)) and σ p (S(3)) are also important. Finally, we analyzed proton magnetic shieldings and found that, for molecules containing Sn as the central atom, σ(H) decreases as the number of heavy halogen substituents (of the same type: either F, Cl, or Br) increases, albeit at different rates for different halogens. σ(H) only increase as the number of halogen substituents increases if the halogen is iodine.

Plasma clot formation and clot lysis to compare effects of different anticoagulation treatments on hemostasis in patients with atrial fibrillation.

PubMed

Königsbrügge, Oliver; Weigel, Günter; Quehenberger, Peter; Pabinger, Ingrid; Ay, Cihan

2018-02-07

The effect of direct oral anticoagulants (DOACs) on turbidimetric measurements of plasma clot formation and susceptibility to fibrinolysis may facilitate a comparison between different classes of anticoagulants in plasma samples. We obtained 424 citrate plasma samples from 226 atrial fibrillation patients on anticoagulation and 24 samples without anticoagulation serving as controls. As comparators, we measured the international normalized ratio (INR) for phenprocoumon samples (N = 166), anti-Xa for low molecular weight heparin (LMWH) samples (N = 42), and DOAC levels with mass spectrometry (dabigatran N = 40, rivaroxaban N = 110, apixaban N = 42). Plasma clot formation and lysis were recorded continuously on a photometer after addition of an activation mix (tissue factor 2 pmol/l and tissue plasminogen activator 333 ng/ml). We used linear regression and ANCOVA for correlation analysis. Clot formation lag phase was prolonged in the presence of anticoagulants in a concentration-dependent manner for DOACs (dabigatran Spearman r = 0.74; rivaroxaban r = 0.78; apixaban r = 0.72, all p < 0.0001), INR dependent for phenprocoumon (r = 0.59, p < 0.0001), anti-Xa level dependent in LMWH samples (r = 0.90, p < 0.0001). Maximum rate of clot formation and peak clot turbidity were reduced in the presence of anticoagulants, but correlated only moderately with the comparator measures of anticoagulation. The clot lysis time was inversely correlated with DOAC concentrations in the presence of recombinant thrombomodulin. A direct ex vivo comparison between the effects of different classes of anticoagulants is possible with turbidimetric measurement of plasma clot formation and lysis. Anticoagulation inhibited clot formation in a plasma concentration manner for DOACs, INR dependent for phenprocoumon, and anti-Xa dependent for LMWH. Susceptibility to fibrinolysis increased with increasing DOAC concentrations.

Wavelength Dependence of Effective Pathlength Factor in Noninvasive Optical Measurements of Human Brain Functions

NASA Astrophysics Data System (ADS)

Sato, Hiroki; Kiguchi, Masashi; Maki, Atsushi

2006-04-01

In the noninvasive optical measurements of human brain functions, the dependence of pathlength factor in an activation area (effective pathlength factor: EPF) on wavelength was examined by simultaneously recording five wavelengths of 678, 692, 750, 782, and 830 nm, with three different source/detector distances of 20, 30, and 40 mm. We obtained an activation signal in the visual cortex using four wavelength pairs, where 830 nm was fixed as one wavelength. The dependence of EPF on the source/detector distance showed similar tendencies when the wavelengths of 692, 750, and 782 nm were considered. This suggests that it is feasible to use these wavelengths paired with an 830 nm wavelength to investigate the same region.

Phase-dependent above-barrier ionization of excited-state electrons.

PubMed

Yang, Weifeng; Song, Xiaohong; Chen, Zhangjin

2012-05-21

The carrier-envelope phase (CEP)-dependent above-barrier ionization (ABI) has been investigated in order to probe the bound-state electron dynamics. It is found that when the system is initially prepared in the excited state, the ionization yield asymmetry between left and right sides can occur both in low-energy and high-energy parts of the photoelectron spectra. Moreover, in electron momentum map, a new interference effect along the direction perpendicular to the laser polarization is found. We show that this interference is related to the competition among different excited states. The interference effect is dependent on CEPs of few-cycle probe pulses, which can be used to trace the superposition information and control the electron wave packet of low excited states.

Channel length dependence of field-effect mobility of c-axis-aligned crystalline In-Ga-Zn-O field-effect transistors

NASA Astrophysics Data System (ADS)

Matsuda, Shinpei; Kikuchi, Erumu; Yamane, Yasumasa; Okazaki, Yutaka; Yamazaki, Shunpei

2015-04-01

Field-effect transistors (FETs) with c-axis-aligned crystalline In-Ga-Zn-O (CAAC-IGZO) active layers have extremely low off-state leakage current. Exploiting this feature, we investigated the application of CAAC-IGZO FETs to LSI memories. A high on-state current is required for the high-speed operation of these LSI memories. The field-effect mobility μFE of a CAAC-IGZO FET is relatively low compared with the electron mobility of single-crystal Si (sc-Si). In this study, we measured and calculated the channel length L dependence of μFE for CAAC-IGZO and sc-Si FETs. For CAAC-IGZO FETs, μFE remains almost constant, particularly when L is longer than 0.3 µm, whereas that of sc-Si FETs decreases markedly as L shortens. Thus, the μFE difference between both FET types is reduced by miniaturization. This difference in μFE behavior is attributed to the different susceptibilities of electrons to phonon scattering. On the basis of this result and the extremely low off-state leakage current of CAAC-IGZO FETs, we expect high-speed LSI memories with low power consumption.

Sexual reproduction and population dynamics: the role of polygyny and demographic sex differences.

PubMed Central

Lindström, J; Kokko, H

1998-01-01

Most models of population dynamics do not take sexual reproduction into account (i.e., they do not consider the role of males). However, assumptions behind this practice--that no demographic sex differences exist and males are always abundant enough to fertilize all the females--are usually not justified in natural populations. On the contrary, demographic sex differences are common, especially in polygynous species. Previous models that consider sexual reproduction report a stabilizing effect through mixing of different genotypes, thus suggesting a decrease in the propensity for complex of dynamics in sexually reproducing populations. Here we show that considering the direct role of males in reproduction and density dependence leads to the conclusion that a two-sex model is not necessarily more stable compared with the corresponding one-sex model. Although solutions exist where sexual reproduction has a stabilizing effect even when no genotypic variability is included (primarily when associated with monogamy), factors like polygyny, sex differences in survival or density dependence, and possible alterations of the primary sex ratio (the Trivers-Willard mechanism), may enlarge the parametric region of complex dynamics. Sexual reproduction therefore does not necessarily increase the stability of population dynamics and can have destabilizing effects, at least in species with complicated mating systems and sexual dimorphism. PMID:9606132

Comparison of different cooling rates for fibroblast and keratinocyte cryopreservation.

PubMed

Naaldijk, Yahaira; Friedrich-Stöckigt, Annett; Sethe, Sebastian; Stolzing, Alexandra

2016-10-01

Easy, cost-effective and reliable cryopreservation protocols are crucial for the successful and effective application of tissue engineering. Several different protocols are in use, but no comprehensive comparisons across different machine-based and manual methods have been made. Here, we compare the effects of different cooling rates on the post-thaw survival and proliferative capacity of two basic cell lines for skin tissue engineering fibroblasts and keratinocytes, cultured and frozen in suspension or as a monolayer. We demonstrate that effectiveness of cryopreservation cannot be reliably determined immediately after thawing: the results at this stage were not indicative of cell growth in culture 3 days post-thaw. Cryopreservation of fibroblasts in an adherent state greatly diminishes their subsequent growth potential. This was not observed when freezing in suspension. In keratinocytes, however, adherent freezing is as effective as freezing in suspension, which could lead to significant cost and labour savings in a tissue-engineering environment. The 'optimal' cryopreservation protocol depends on cell type and intended use. Where time, ease and cost are dominant factors, the direct freezing into a nitrogen tank (straight freeze) approach remains a viable method. The most effective solution across the board, as measured by viability 3 days post-thaw, was the commonly used, freezing container method. Where machine-controlled cryopreservation is deemed important for tissue-engineering Good Manufacturing Practice, we present results using a portfolio of different cooling rates, identifying the 'optimal' protocol depending on cell type and culture method. Copyright © 2013 John Wiley & Sons, Ltd. Copyright © 2013 John Wiley & Sons, Ltd.

The differences in matrix effect between supercritical fluid chromatography and reversed phase liquid chromatography coupled to ESI/MS.

PubMed

Svan, Alfred; Hedeland, Mikael; Arvidsson, Torbjörn; Pettersson, Curt E

2018-02-13

For many sample matrices, matrix effects are a troublesome phenomenon using the electrospray ionization source. The increasing use of supercritical fluid chromatography with CO 2 in combination with the electrospray ionization source for MS detection is therefore raising questions: is the matrix effect behaving differently using SFC in comparison with reversed phase LC? This was investigated using urine, plasma, influent- and effluent-wastewater as sample matrices. The matrix effect was evaluated using the post-extraction addition method and through post-column infusions. Matrix effect profiles generated from the post-column infusions in combination with time of flight-MS detection provided the most valuable information for the study. The combination of both qualitative and semi-quantitative information with the ability to use HRMS-data for identifying interfering compounds from the same experiment was very useful, and has to the authors' knowledge not been used this way before. The results showed that both LC and SFC are affected by matrix effects, however differently depending on sample matrix. Generally, both suppressions and enhancements were seen, with a higher amount of enhancements for LC, where 65% of all compounds and all sample matrices were enhanced, compared to only 7% for SFC. Several interferences were tentatively identified, with phospholipids, creatinine, and metal ion clusters as examples of important interferences, with different impact depending on chromatographic technique. SFC needs a different strategy for limiting matrix interferences, owing to its almost reverse retention order compared to RPLC. Copyright © 2017 Elsevier B.V. All rights reserved.

Influence of grain orientation on the incipient oxidation behavior of Haynes 230 at 900 °C

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Xu, E-mail: xuw388@mail.usask.ca; Fan, Fan; Szpunar, Jerzy A.

Ni-based superalloy Haynes 230 is used in many applications such as very high temperature reactor (VHTR) or solid oxide fuel cells (SOFCs) where it is exposed to high temperature service environment. In order to improve the resistance for high temperature oxidation, the effect of crystallographic orientation on the early stage oxidation was investigated. It was demonstrated that different oxide thicknesses are formed on grains having different orientations. Comparison of electron backscatter diffraction (EBSD) orientation maps before and after oxidation at 900 °C indicates that grains near (111) orientation, especially with the deviation angle from <111> that is smaller than 20°,more » are more oxidation resistant than grains of other orientations. Correlation between the results of electron backscatter diffraction (EBSD) and atomic force microscopy (AFM) was used to compare the oxidation rate of grains having different crystallographic orientation. The oxidation rate was found to change with the crystallographic orientation as follows (111) < (110) < (100), also it was demonstrated that the oxidation rate changes are a nearly linear function of the angle of deviation from <111> direction. The morphology of surface oxide also depends on the orientation of grains. - Highlights: • Comparison of EBSD maps before and after oxidation allows to investigate the effect of orientation on oxidation in a more direct way; • Effect of crystallographic orientation on oxidation behavior of alloy 230 is studied by combination of EBSD and AFM; • Different thickness of oxide is formed on grain with different orientation and dependence of anisotropic oxidation behavior is discussed; • The morphology of grains is also orientation dependence.« less

Analysis of regional brain mitochondrial bioenergetics and susceptibility to mitochondrial inhibition utilizing a microplate based system

PubMed Central

Sauerbeck, Andrew; Pandya, Jignesh; Singh, Indrapal; Bittman, Kevin; Readnower, Ryan; Bing, Guoying; Sullivan, Patrick

2012-01-01

The analysis of mitochondrial bioenergetic function typically has required 50–100 μg of protein per sample and at least 15 min per run when utilizing a Clark-type oxygen electrode. In the present work we describe a method utilizing the Seahorse Biosciences XF24 Flux Analyzer for measuring mitochondrial oxygen consumption simultaneously from multiple samples and utilizing only 5 μg of protein per sample. Utilizing this method we have investigated whether regionally based differences exist in mitochondria isolated from the cortex, striatum, hippocampus, and cerebellum. Analysis of basal mitochondrial bioenergetics revealed that minimal differences exist between the cortex, striatum, and hippocampus. However, the cerebellum exhibited significantly slower basal rates of Complex I and Complex II dependent oxygen consumption (p < 0.05). Mitochondrial inhibitors affected enzyme activity proportionally across all samples tested and only small differences existed in the effect of inhibitors on oxygen consumption. Investigation of the effect of rotenone administration on Complex I dependent oxygen consumption revealed that exposure to 10 pM rotenone led to a clear time dependent decrease in oxygen consumption beginning 12 min after administration (p < 0.05). These studies show that the utilization of this microplate based method for analysis of mitochondrial bioenergetics is effective at quantifying oxygen consumption simultaneously from multiple samples. Additionally, these studies indicate that minimal regional differences exist in mitochondria isolated from the cortex, striatum, or hippocampus. Furthermore, utilization of the mitochondrial inhibitors suggests that previous work indicating regionally specific deficits following systemic mitochondrial toxin exposure may not be the result of differences in the individual mitochondria from the affected regions. PMID:21402103

EEJ and EIA variations during modeling substorms with different onset moments

NASA Astrophysics Data System (ADS)

Klimenko, V. V.; Klimenko, M. V.

2015-11-01

This paper presents the simulations of four modeling substorms with different moment of substorm onset at 00:00 UT, 06:00 UT, 12:00 UT, and 18:00 UT for spring equinoctial conditions in solar activity minimum. Such investigation provides opportunity to examine the longitudinal dependence of ionospheric response to geomagnetic substorms. Model runs were performed using modified Global Self-consistent Model of the Thermosphere, Ionosphere and Protonosphere (GSM TIP). We analyzed GSM TIP simulated global distributions of foF2, low latitude electric field and ionospheric currents at geomagnetic equator and their disturbances at different UT moments substorms. We considered in more detail the variations in equatorial ionization anomaly, equatorial electrojet and counter equatorial electrojet during substorms. It is shown that: (1) the effects in EIA, EEJ and CEJ strongly depend on the substorm onset moment; (2) disturbances in equatorial zonal current density during substorm has significant longitudinal dependence; (3) the observed controversy on the equatorial ionospheric electric field signature of substorms can depend on the substorm onset moments, i.e., on the longitudinal variability in parameters of the thermosphere-ionosphere system.

Correlational selection on personality and social plasticity: morphology and social context determine behavioural effects on mating success.

PubMed

Montiglio, Pierre-Olivier; Wey, Tina W; Chang, Ann T; Fogarty, Sean; Sih, Andrew

2017-03-01

Despite a central line of research aimed at quantifying relationships between mating success and sexually dimorphic traits (e.g., ornaments), individual variation in sexually selected traits often explains only a modest portion of the variation in mating success. Another line of research suggests that a significant portion of the variation in mating success observed in animal populations could be explained by correlational selection, where the fitness advantage of a given trait depends on other components of an individual's phenotype and/or its environment. We tested the hypothesis that interactions between multiple traits within an individual (phenotype dependence) or between an individual's phenotype and its social environment (context dependence) can select for individual differences in behaviour (i.e., personality) and social plasticity. To quantify the importance of phenotype- and context-dependent selection on mating success, we repeatedly measured the behaviour, social environment and mating success of about 300 male stream water striders, Aquarius remigis. Rather than explaining individual differences in long-term mating success, we instead quantified how the combination of a male's phenotype interacted with the immediate social context to explain variation in hour-by-hour mating decisions. We suggest that this analysis captures more of the mechanisms leading to differences in mating success. Males differed consistently in activity, aggressiveness and social plasticity. The mating advantage of these behavioural traits depended on male morphology and varied with the number of rival males in the pool, suggesting mechanisms selecting for consistent differences in behaviour and social plasticity. Accounting for phenotype and context dependence improved the amount of variation in male mating success we explained statistically by 30-274%. Our analysis of the determinants of male mating success provides important insights into the evolutionary forces that shape phenotypic variation. In particular, our results suggest that sexual selection is likely to favour individual differences in behaviour, social plasticity (i.e., individuals adjusting their behaviour), niche preference (i.e., individuals dispersing to particular social conditions) or social niche construction (i.e., individuals modifying the social environment). The true effect of sexual traits can only be understood in interaction with the individual's phenotype and environment. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

Intangible costs of alcohol dependence from the perspective of patients and their relatives: A contingent valuation study.

PubMed

Mosquera Nogueira, Jacinto; Rodríguez-Míguez, Eva

2018-04-15

Alcohol dependence causes multiple problems not only for the person suffering dependence but also for others. In this study, the contingent valuation method is proposed to measure the intangible effects of alcohol dependence from the perspective of the persons directly involved: the patients and their relatives. Interviews were conducted with 145 patients and 61 relatives. Intangible effects of alcohol dependence were determined based on willingness to pay for a hypothetical treatment for dependence, with different success scenarios (100% and 50%). The mean monthly willingness to pay among the alcohol-dependent population was €129 and €168, respectively, for the treatments with 100% and 50% success. The willingness to pay of relatives was greater in both scenarios (€307 and €420, respectively), which could be explained by their greater perception of the family, labour, and health problems resulting from alcohol dependence. Regression analysis showed that patients' willingness to pay is positively related to treatment efficacy, personal income and moderate health deterioration, and negatively related to feeling discouraged and depressed. The results from this study can be applied to economic valuation studies that aim to measure the benefits of programs intended to reduce the prevalence of alcohol dependence. The intangible costs estimated can be added to the direct and indirect costs commonly used.

Body size-dependent Cd accumulation in the zebra mussel Dreissena polymorpha from different routes.

PubMed

Tang, Wen-Li; Evans, Douglas; Kraemer, Lisa; Zhong, Huan

2017-02-01

Understanding body size-dependent metal accumulation in aquatic organisms (i.e., metal allometry) is critical in interpreting biomonitoring data. While growth has received the most attention, little is known about controls of metal exposure routes on metal allometry. Here, size-dependent Cd accumulation in zebra mussels (Dreissena polymorpha) from different routes were investigated by exposing mussels to A.( 111 Cd spiked algae+ 113 Cd spiked river water) or B.( 111 Cd spiked sediments+ 113 Cd spiked river water). After exposure, 111 Cd or 113 Cd levels in mussel tissue were found to be negatively correlated with tissue weight, while Cd allometry coefficients (b values) were dependent on Cd exposure routes: -0.664 for algae, -0.241 for sediments and -0.379 for river water, compared to -0.582 in un-exposed mussels. By comparing different Cd exposure routes, we found that size-dependent Cd bioaccumulation from algae or river water could be more responsible for the overall size-dependent Cd accumulation in mussels, and the relative importance of the two sources was dependent on mussel size ranges: Cadmium obtained from algae (algae-Cd) was more important in size-dependent Cd accumulation in smaller mussels (tissue dry weight < 5 mg), while river water-Cd became more important in larger individuals (tissue dry weight > 5 mg). In contrast, sediment-Cd contributed only a small amount to Cd accumulation in zebra mussels and may have little effect on size-dependent Cd bioaccumulation. Our results suggest that size-dependent Cd accumulation in mussels could be largely affected by exposure routes, which should be considered when trying to interpret Cd biomonitoring data of zebra mussels. Copyright © 2016 Elsevier Ltd. All rights reserved.

Atmospheric Moisture Budget and Spatial Resolution Dependence of Precipitation Extremes in Aquaplanet Simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Qing; Leung, Lai-Yung R.; Rauscher, Sara

This study investigates the resolution dependency of precipitation extremes in an aqua-planet framework. Strong resolution dependency of precipitation extremes is seen over both tropics and extra-tropics, and the magnitude of this dependency also varies with dynamical cores. Moisture budget analyses based on aqua-planet simulations with the Community Atmosphere Model (CAM) using the Model for Prediction Across Scales (MPAS) and High Order Method Modeling Environment (HOMME) dynamical cores but the same physics parameterizations suggest that during precipitation extremes moisture supply for surface precipitation is mainly derived from advective moisture convergence. The resolution dependency of precipitation extremes mainly originates from advective moisturemore » transport in the vertical direction. At most vertical levels over the tropics and in the lower atmosphere over the subtropics, the vertical eddy transport of mean moisture field dominates the contribution to precipitation extremes and its resolution dependency. Over the subtropics, the source of moisture, its associated energy, and the resolution dependency during extremes are dominated by eddy transport of eddies moisture at the mid- and upper-troposphere. With both MPAS and HOMME dynamical cores, the resolution dependency of the vertical advective moisture convergence is mainly explained by dynamical changes (related to vertical velocity or omega), although the vertical gradients of moisture act like averaging kernels to determine the sensitivity of the overall resolution dependency to the changes in omega at different vertical levels. The natural reduction of variability with coarser resolution, represented by areal data averaging (aggregation) effect, largely explains the resolution dependency in omega. The thermodynamic changes, which likely result from non-linear feedback in response to the large dynamical changes, are small compared to the overall changes in dynamics (omega). However, after excluding the data aggregation effect in omega, thermodynamic changes become relatively significant in offsetting the effect of dynamics leading to reduce differences between the simulated and aggregated results. Compared to MPAS, the simulated stronger vertical motion with HOMME also results in larger resolution dependency. Compared to the simulation at fine resolution, the vertical motion during extremes is insufficiently resolved/parameterized at the coarser resolution even after accounting for the natural reduction in variability with coarser resolution, and this is more distinct in the simulation with HOMME. To reduce uncertainties in simulated precipitation extremes, future development in cloud parameterizations must address their sensitivity to spatial resolution as well as dynamical cores.« less

Constraining Anisotropic Lorentz Violation via the Spectral-lag Transition of GRB 160625B

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wei, Jun-Jie; Wu, Xue-Feng; Shao, Lang

Violations of Lorentz invariance can lead to an energy-dependent vacuum dispersion of light, which results in arrival-time differences of photons with different energies arising from a given transient source. In this work, direction-dependent dispersion constraints are obtained on nonbirefringent Lorentz-violating effects using the observed spectral lags of the gamma-ray burst GRB 160625B. This burst has unusually large high-energy photon statistics, so we can obtain constraints from the true spectral time lags of bunches of high-energy photons rather than from the rough time lag of a single highest-energy photon. Also, GRB 160625B is the only burst to date having a well-definedmore » transition from positive lags to negative lags, providing a unique opportunity to distinguish Lorentz-violating effects from any source-intrinsic time lag in the emission of photons of different energy bands. Our results place comparatively robust two-sided constraints on a variety of isotropic and anisotropic coefficients for Lorentz violation, including the first bounds on Lorentz-violating effects from operators of mass dimension 10 in the photon sector.« less

Different effects of executive and visuospatial working memory on visual consciousness.

PubMed

De Loof, Esther; Poppe, Louise; Cleeremans, Axel; Gevers, Wim; Van Opstal, Filip

2015-11-01

Consciousness and working memory are two widely studied cognitive phenomena. Although they have been closely tied on a theoretical and neural level, empirical work that investigates their relation is largely lacking. In this study, the relationship between visual consciousness and different working memory components is investigated by using a dual-task paradigm. More specifically, while participants were performing a visual detection task to measure their visual awareness threshold, they had to concurrently perform either an executive or visuospatial working memory task. We hypothesized that visual consciousness would be hindered depending on the type and the size of the load in working memory. Results showed that maintaining visuospatial content in working memory hinders visual awareness, irrespective of the amount of information maintained. By contrast, the detection threshold was progressively affected under increasing executive load. Interestingly, increasing executive load had a generic effect on detection speed, calling into question whether its obstructing effect is specific to the visual awareness threshold. Together, these results indicate that visual consciousness depends differently on executive and visuospatial working memory.

Sample-size needs for forestry herbicide trials

Treesearch

S.M. Zedaker; T.G. Gregoire; James H. Miller

1994-01-01

Forest herbicide experiments are increasingly being designed to evaluate smaller treatment differences when comparing existing effective treatments, tank mix ratios, surfactants, and new low-rate products. The ability to detect small differences in efficacy is dependent upon the relationship among sample size. type I and II error probabilities, and the coefficients of...

Exciton-dominant Electroluminescence from a Diode of Monolayer MoS2

DTIC Science & Technology

2014-05-14

caused by a phonon-assisted nonradiative process, as the two peaks display different current dependencies. We pro- pose this is a different effect...monolayer MoS2. The Auger process opens up a nonradiative recombination channel for electron-hole pair recombination. If the Auger process is

Are Automatic Imitation and Spatial Compatibility Mediated by Different Processes?

ERIC Educational Resources Information Center

Cooper, Richard P.; Catmur, Caroline; Heyes, Cecilia

2013-01-01

Automatic imitation or "imitative compatibility" is thought to be mediated by the mirror neuron system and to be a laboratory model of the motor mimicry that occurs spontaneously in naturalistic social interaction. Imitative compatibility and spatial compatibility effects are known to depend on different stimulus dimensions--body…

Hormesis and Paradoxical Effects of Drooping Birch (Betula pendula Roth) Parameters Under Motor Traffic Pollution

PubMed Central

2015-01-01

Various plant indexes are used or recommended for bioindication. However, the nonmonotonic dose–response dependences (hormesis and paradoxical effects) of these indexes are insufficiently explored upon exposure to pollution. We studied the dependences of these Betula pendula indexes on the intensity of motor traffic pollution. Regression analysis did not reveal any dependence of chlorophyll and carotenoid content on traffic intensity (in 2008 and 2010-2013). Lipid peroxidation rate had different versions of paradoxical effects in 2008 and 2010 to 2012 and increased in comparison with control under an increase in pollution level in 2013. In 2010 to 2012, all dose–response dependences for total protein and thiol group content were biphasic and multiphasic paradoxical effects. In 2013, an increase in traffic intensity induced a linear reduction in protein content and an increase in thiol group level in comparison with the control. In most cases, the studied phenological indexes and seed production decreased monotonically in comparison with the control following an increase in traffic intensity. Only in 2010 and 2013, share of fallen leaves had hormesis and paradoxical effect accordingly. Fluctuating asymmetry had a paradoxical effect and hormesis in 2008 and 2012, accordingly, and increased in comparison with the control under an increase in the level of pollution in 2010 to 2011. PMID:26676071

Analysis of human hair by Raman microspectroscopy

NASA Astrophysics Data System (ADS)

Plascencia-Castro, A. S.; Cordova-Fraga, T.; Piña-Ruiz, A. L.; Hernández-Rayas, A.; Bernal, J. J.

2017-04-01

Raman microspectroscopy is an optical compound identification technique, which is widely used nowadays for different field applications. A crucial part of this technique is the focus given to the sample in the microscope because it depends on which part of the sample it will analyze. In this work, the effects of irradiating a natural hair samples, obtained from women aged 18 to 55, with a monochromatic light of the Raman spectrometer in two different focus is presented. Two different spectra were obtained with a peak in common. Depending on the information wanted, how the sample is focused plays a crucial role, either way the spectra is information-rich and may be used for biomedical applications.

Dynamics of electronic transitions and frequency dependence of negative capacitance in semiconductor diodes under high forward bias

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bansal, Kanika; Datta, Shouvik; Henini, Mohamed

2014-09-22

We observed qualitatively dissimilar frequency dependence of negative capacitance under high charge injection in two sets of functionally different junction diodes: III-V based light emitting and Si-based non-light emitting diodes. Using an advanced approach based on bias activated differential capacitance, we developed a generalized understanding of negative capacitance phenomenon which can be extended to any diode based device structure. We explained the observations as the mutual competition of fast and slow electronic transition rates which are different in different devices. This study can be useful in understanding the interfacial effects in semiconductor heterostructures and may lead to superior device functionality.

The influence of message framing, intention to quit smoking, and nicotine dependence on the persuasiveness of smoking cessation messages.

PubMed

Moorman, Marjolein; van den Putte, Bas

2008-10-01

This study explores the combined effect of message framing, intention to quit smoking, and nicotine dependence on the persuasiveness of smoking cessation messages. Pre- and post-message measures of quit intention, attitude toward smoking cessation, and perceived behavioral control were taken in two separate waves from current cigarette smokers with varying levels of nicotine dependence (N=151). In the second wave, participants were randomly assigned to one of two groups. In the first group, participants read a smoking cessation message which emphasized the benefits of quitting (positive frame). In the second group participants read a message which emphasized the costs of not quitting (negative frame). Results show that smokers' intentions to quit smoking and their level of nicotine dependence jointly influence the persuasiveness of positive and negative message frames. When nicotine dependence and quitting intention are both high, a negative frame works best. Conversely, a positive frame is preferable when nicotine dependence or quitting intention is low. Smokers' level of processing is proposed as the underlying mechanism explaining the different effects of message frames.

Fracture strength of the particulate-reinforced ultra-high temperature ceramics based on a temperature dependent fracture toughness model

NASA Astrophysics Data System (ADS)

Wang, Ruzhuan; Li, Weiguo; Ji, Baohua; Fang, Daining

2017-10-01

The particulate-reinforced ultra-high temperature ceramics (pUHTCs) have been particularly developed for fabricating the leading edge and nose cap of hypersonic vehicles. They have drawn intensive attention of scientific community for their superior fracture strength at high temperatures. However, there is no proper model for predicting the fracture strength of the ceramic composites and its dependency on temperature. In order to account for the effect of temperature on the fracture strength, we proposed a concept called energy storage capacity, by which we derived a new model for depicting the temperature dependent fracture toughness of the composites. This model gives a quantitative relationship between the fracture toughness and temperature. Based on this temperature dependent fracture toughness model and Griffith criterion, we developed a new fracture strength model for predicting the temperature dependent fracture strength of pUHTCs at different temperatures. The model takes into account the effects of temperature, flaw size and residual stress without any fitting parameters. The predictions of the fracture strength of pUHTCs in argon or air agreed well with the experimental measurements. Additionally, our model offers a mechanism of monitoring the strength of materials at different temperatures by testing the change of flaw size. This study provides a quantitative tool for design, evaluation and monitoring of the fracture properties of pUHTCs at high temperatures.

Vaccination against rubella: Analysis of the temporal evolution of the age-dependent force of infection and the effects of different contact patterns

NASA Astrophysics Data System (ADS)

Amaku, M.; Coutinho, F. A.; Azevedo, R. S.; Burattini, M. N.; Lopez, L. F.; Massad, E.

2003-05-01

In this paper, we analyze the temporal evolution of the age-dependent force of infection and incidence of rubella, after the introduction of a very specific vaccination program in a previously nonvaccinated population where rubella was in endemic steady state. We deduce an integral equation for the age-dependent force of infection, which depends on a number of parameters that can be estimated from the force of infection in a steady state prior to the vaccination program. We present the results of our simulations, which are compared with observed data. We also examine the influence of contact patterns among members of a community on the age-dependent intensity of transmission of rubella and on the results of vaccination strategies. As an example of the theory proposed, we calculate the effects of vaccination strategies for four communities from Caieiras (Brazil), Huixquilucan (Mexico), Finland, and the United Kingdom. The results for each community differ considerably according to the distinct intensity and pattern of transmission in the absence of vaccination. We conclude that this simple vaccination program is not very efficient (very slow) in the goal of eradicating the disease. This gives support to a mixed strategy, proposed by Massad et al., accepted and implemented by the government of the State of São Paulo, Brazil.

chroma: Chromatic effects for LSST weak lensing

NASA Astrophysics Data System (ADS)

Meyers, Joshua E.; Burchat, Patricia R.

2018-04-01

Chroma investigates biases originating from two chromatic effects in the atmosphere: differential chromatic refraction (DCR), and wavelength dependence of seeing. These biases arise when using the point spread function (PSF) measured with stars to estimate the shapes of galaxies with different spectral energy distributions (SEDs) than the stars.

Health inequalities by socioeconomic characteristics in Spain: the economic crisis effect.

PubMed

Barroso, Clara; Abásolo, Ignacio; Cáceres, José J

2016-04-11

An economic crisis can widen health inequalities between individuals. The aim of this paper is to explore differences in the effect of socioeconomic characteristics on Spaniards' self-assessed health status, depending on the Spanish economic situation. Data from the 2006-2007 and 2011-2012 National Health Surveys were used and binary logit and probit models were estimated to approximate the effects of socioeconomic characteristics on the likelihood to report good health. The difference between high and low education levels leads to differences in the likelihood to report good health of 16.00-16.25 and 18.15-18.22 percentage points in 2006-07 and 2011-12, respectively. In these two periods, the difference between employees and unemployed is 5.24-5.40 and 4.60-4.90 percentage points, respectively. Additionally, the difference between people who live in households with better socioeconomic conditions and those who are in worse situation reaches 5.37-5.46 and 3.63-3.74 percentage points for the same periods, respectively. The magnitude of the contribution of socioeconomic characteristics to health inequalities changes with the economic cycle; but this effect is different depending on the socioeconomic characteristics indicator that is being measured. In recessive periods, health inequalities due to education level increase, but those linked to individual professional status and household living conditions are attenuated. When the joint effects of individuals' characteristics are considered, the economic crisis brings about a slight increase in the inequalities in the probability of reporting good health between the two extreme profiles of individuals. The design of public policies aimed at preventing any worsening of health inequalities during recession periods should take into account these differential effects of socioeconomic characteristics indicators on health inequalities.