1,185 research outputs found

    Chronic Stress during Adolescence Alters Alcohol-Induced Conditioned Place Preference in Mice Selectively Bred for High Alcohol Preference but no Low Alcohol Preference

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    Chronic stress exposure during adolescence is associated with more long-lasting negative consequences than exposure during adulthood. Adolescent chronic stress exposure has long-lasting effects on physiology and behavior, including an increased risk of developing an alcohol use disorder (AUD) later in life. This relationship is particularly true in individuals with a familial history of AUDs. Recent research has shown that chronic stress in adolescent mice increased voluntary alcohol consumption in adulthood, but did not do so in adult mice. However, little is known about the mechanism of the relationship between adolescent chronic stress and increased alcohol consumption in adulthood. Evidence suggests that chronic stress exposure during adolescence has long-term effects on the developing brain, including areas important for sensitivity to the rewarding effects of alcohol. The over-arching aim of the current study was to explore the effects of adolescent chronic stress on sensitivity to the motivational effects of alcohol in adulthood. Three stress treatment groups were used, including subjects exposed to stress during adolescence, subjects exposed to stress during adulthood, and subjects not exposed to stress. Within each stress treatment group, high-alcohol preferring (HAP2) and low-alcohol preferring (LAP2) mice were represented, to mimic differences in familial AUD history. Thirty days after stress exposure, all subjects began a conditioned place preference (CPP) paradigm, a behavioral task that measures the sensitivity to alcohol\u27s rewarding effects. Since re-exposure to a stressor has been associated with an increased risk in relapse and other drug-seeking behaviors, half of the subjects in each stress treatment group were re-exposed to the original stressor (RS) before the CPP posttest. Overall, LAP2 mice showed greater CPP than HAP2 mice, which supports more recent literature suggesting that an inverse relationship between alcohol consumption and CPP expression may exist. In contrast to what was hypothesized, adolescent stress exposure decreased CPP expression in the HAP2 subjects during the first portion of testing. This finding may support an inverse relationship between alcohol consumption and CPP expression, when interpreted such that subjects exposed to stress during adolescence may drink more during adulthood because they are less sensitive to the rewarding effects of alcohol. In LAP2 subjects, there were no differences in CPP expression between the stress treatment groups, supporting past research suggesting that HAP2 mice are more sensitive to alterations in drug-related behaviors following stress exposure. RS did not produce alterations in CPP in either line. Overall, the findings of the current study suggest that one explanation for why individuals exposed to stress during adolescence may increase alcohol consumption during adulthood might be because more alcohol is required in order to reach the desired perceived rewarding effects of the drug, especially in those with a familial history of AUDs

    A new method of quantization of classical solutions

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    Using stochastic quantization method we derive equations for correlators of quantum fluctuations around the classical solution in the massless phi^4 theory. The obtained equations are then solved in the lowest orders of perturbation theory, and the first correction to the free propagator of a quantum fluctuation is calculated.Comment: 8 page

    Prenatal alcohol and tetrahydrocannabinol exposure: Effects on spatial and working memory

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    IntroductionAlcohol and cannabis are widely used recreational drugs that can negatively impact fetal development, leading to cognitive impairments. However, these drugs may be used simultaneously and the effects of combined exposure during the prenatal period are not well understood. Thus, this study used an animal model to investigate the effects of prenatal exposure to ethanol (EtOH), Δ-9-tetrahydrocannabinol (THC), or the combination on spatial and working memory.MethodsPregnant Sprague–Dawley rats were exposed to vaporized ethanol (EtOH; 68 ml/h), THC (100 mg/ml), the combination, or vehicle control during gestational days 5–20. Adolescent male and female offspring were evaluated using the Morris water maze task to assess spatial and working memory.ResultsPrenatal THC exposure impaired spatial learning and memory in female offspring, whereas prenatal EtOH exposure impaired working memory. The combination of THC and EtOH did not exacerbate the effects of either EtOH or THC, although subjects exposed to the combination were less thigmotaxic, which might represent an increase in risk-taking behavior.DiscussionOur results highlight the differential effects of prenatal exposure to THC and EtOH on cognitive and emotional development, with substance- and sex-specific patterns. These findings highlight the potential harm of THC and EtOH on fetal development and support public health policies aimed at reducing cannabis and alcohol use during pregnancy

    Induced two-photon decay of the 2s level and the rate of cosmological hydrogen recombination

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    Induced emission due to the presence of soft CMB photons slightly increases the two-photon decay rate of the 2s level of hydrogen defining the rate of cosmological recombination. This correspondingly changes the degree of ionization, the visibility function and the resulting primordial temperature anisotropies and polarization of the CMB on the percent level. These changes exceed the precision of the widely used CMBFAST and CAMB codes by more than one order of magnitude and can be easily taken into account.Comment: 5 pages, 5 figure, accepted by Astronomy and Astrophysic

    Irreversible quantum graphs

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    Irreversibility is introduced to quantum graphs by coupling the graphs to a bath of harmonic oscillators. The interaction which is linear in the harmonic oscillator amplitudes is localized at the vertices. It is shown that for sufficiently strong coupling, the spectrum of the system admits a new continuum mode which exists even if the graph is compact, and a {\it single} harmonic oscillator is coupled to it. This mechanism is shown to imply that the quantum dynamics is irreversible. Moreover, it demonstrates the surprising result that irreversibility can be introduced by a "bath" which consists of a {\it single} harmonic oscillator

    Deep subsurface drip irrigation using coal-bed sodic water: Part II. Geochemistry

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    Waters with low salinity and high sodium adsorption ratios (SARs) present a challenge to irrigation because they degrade soil structure and infiltration capacity. In the Powder River Basin of Wyoming, such low salinity (electrical conductivity, EC 2.1 mS cm−1) and high-SAR (54) waters are co-produced with coal-bed methane and some are used for subsurface drip irrigation (SDI). The SDI system studied mixes sulfuric acid with irrigation water and applies water year-round via drip tubing buried 92 cm deep. After six years of irrigation, SAR values between 0 and 30 cm depth (0.5–1.2) are only slightly increased over non-irrigated soils (0.1–0.5). Only 8–15% of added Na has accumulated above the drip tubing. Sodicity has increased in soil surrounding the drip tubing, and geochemical simulations show that two pathways can generate sodic conditions. In soil between 45-cm depth and the drip tubing, Na from the irrigation water accumulates as evapotranspiration concentrates solutes. SAR values \u3e12, measured by 1:1 water–soil extracts, are caused by concentration of solutes by factors up to 13. Low-EC (\u3c0.7 mS cm−1) is caused by rain and snowmelt flushing the soil and displacing ions in soil solution. Soil below the drip tubing experiences lower solute concentration factors (1–1.65) due to excess irrigation water and also contains relatively abundant native gypsum (2.4 ± 1.7 wt.%). Geochemical simulations show gypsum dissolution decreases soil-water SAR to \u3c7 and increases the EC to around 4.1 mS cm−1, thus limiting negative impacts from sodicity. With sustained irrigation, however, downward flow of excess irrigation water depletes gypsum, increasing soil-water SAR to \u3e14 and decreasing EC in soil water to 3.2 mS cm−1. Increased sodicity in the subsurface, rather than the surface, indicates that deep SDI can be a viable means of irrigating with sodic waters

    Deep subsurface drip irrigation using coal-bed sodic water: Part II. Geochemistry

    Get PDF
    Waters with low salinity and high sodium adsorption ratios (SARs) present a challenge to irrigation because they degrade soil structure and infiltration capacity. In the Powder River Basin of Wyoming, such low salinity (electrical conductivity, EC 2.1 mS cm−1) and high-SAR (54) waters are co-produced with coal-bed methane and some are used for subsurface drip irrigation (SDI). The SDI system studied mixes sulfuric acid with irrigation water and applies water year-round via drip tubing buried 92 cm deep. After six years of irrigation, SAR values between 0 and 30 cm depth (0.5–1.2) are only slightly increased over non-irrigated soils (0.1–0.5). Only 8–15% of added Na has accumulated above the drip tubing. Sodicity has increased in soil surrounding the drip tubing, and geochemical simulations show that two pathways can generate sodic conditions. In soil between 45-cm depth and the drip tubing, Na from the irrigation water accumulates as evapotranspiration concentrates solutes. SAR values \u3e12, measured by 1:1 water–soil extracts, are caused by concentration of solutes by factors up to 13. Low-EC (\u3c0.7 mS cm−1) is caused by rain and snowmelt flushing the soil and displacing ions in soil solution. Soil below the drip tubing experiences lower solute concentration factors (1–1.65) due to excess irrigation water and also contains relatively abundant native gypsum (2.4 ± 1.7 wt.%). Geochemical simulations show gypsum dissolution decreases soil-water SAR to \u3c7 and increases the EC to around 4.1 mS cm−1, thus limiting negative impacts from sodicity. With sustained irrigation, however, downward flow of excess irrigation water depletes gypsum, increasing soil-water SAR to \u3e14 and decreasing EC in soil water to 3.2 mS cm−1. Increased sodicity in the subsurface, rather than the surface, indicates that deep SDI can be a viable means of irrigating with sodic waters

    One- and two-proton transfer reactions with vibrational Nuclei

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    We extend a semiclassical model of transfer reactions to the case in which one of the collision partners is a vibrational nucleus. The model is applied to one- and two-proton stripping reactions in the 37Cl + 98Mo system, for which a rapid transition from normal to anomalous slope in the two proton transfer reaction at energies around the Coulomb barrier is experimentally observed. This behavior is satisfactorily reproduced by the present extension of the model.Comment: LaTeX, 10 pages, 1 figure (PostScript

    Simulated Microgravity Increases Cutaneous Blood Flow in the Head and Leg of Humans

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    The cutaneous micro-circulation vasodilates during acute 6 deg. head-down tilt (HDT, simulated microgravity) relative to upright conditions, more in the lower body than in the upper body. We expected that relative magnitudes of and differences between upper and lower body cutaneous blood flow elevation would be sustained during initial acclimation to simulated microgravity. We measured cutaneous micro-vascular blood flow with laser-Doppler flowmetry at the leg (over the distal tibia) and cheek (over the zygomatic arch) of eight healthy men before, during, and after 24 h of HDT. Results were calculated as a percentage of baseline value (100% measured during pre-tilt upright sitting). Cutaneous blood flow in the cheek increased significantly to 165 +/- 37% (mean + SE, p less than 0.05) at 9-12 h HDT, then returned to near baseline values by 24 h HDT (114 +/- 29%, NSD), despite increased local arterial pressure. Microvascular flow in the leg remained significantly elevated above baseline throughout 24 h HDT (427 +/- 85% at 3 h HDT and 215 +/- 142% at 24 h HDT, p less than 0.05). During the 6-h upright sitting recovery period, cheek and leg blood flow levels returned to near pre-tilt baseline values. Because hydrostatic effects of HDT increase local arterial pressure at the carotid sinus, baroreflex-mediated withdrawal of sympathetic tone probably contributed to increased microvascular flows at the head and leg during HDT. In the leg, baroreflex effects combined with minimal stimulation of local veno-arteriolar and myogenic autoregulatory vasoconstriction to elicit relatively larger and more sustained increases in cutaneous flow during HDT. In the cheek, delayed myogenic vasoconstriction and/or humoral effects apparently compensated for flow elevation by 24 h of HDT. Therefore, localized vascular adaptations to gravity probably explain differences in acclimation of lower and upper body blood flow to HDT and actual microgravity
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