High-Q Magnetic Levitation and Control of Superconducting Microspheres at Millikelvin Temperatures.

We report the levitation of a superconducting lead-tin sphere with 100 µm diameter (corresponding to a mass of 5.6 µg) in a static magnetic trap formed by two coils in an anti-Helmholtz configuration, with adjustable resonance frequencies up to 240 Hz. The center-of-mass motion of the sphere is monitored magnetically using a dc superconducting quantum interference device as well as optically and exhibits quality factors of up to 2.6×10^{7}. We also demonstrate 3D magnetic feedback control of the motion of the sphere. The setup is housed in a dilution refrigerator operating at 15 mK. By implementing a cryogenic vibration isolation system, we can attenuate environmental vibrations at 200 Hz by approximately 7 orders of magnitude. The combination of low temperature, large mass, and high quality factor provides a promising platform for testing quantum physics in previously unexplored regimes with high mass and long coherence times.

Experimental Determination of Irreversible Entropy Production in out-of-Equilibrium Mesoscopic Quantum Systems.

By making use of a recently proposed framework for the inference of thermodynamic irreversibility in bosonic quantum systems, we experimentally measure and characterize the entropy production rates in the nonequilibrium steady state of two different physical systems-a micromechanical resonator and a Bose-Einstein condensate-each coupled to a high finesse cavity and hence also subject to optical loss. Key features of our setups, such as the cooling of the mechanical resonator and signatures of a structural quantum phase transition in the condensate, are reflected in the entropy production rates. Our work demonstrates the possibility to explore irreversibility in driven mesoscopic quantum systems and paves the way to a systematic experimental assessment of entropy production beyond the microscopic limit.

New boron based salts for lithium-ion batteries using conjugated ligands.

A new anion design concept, based on combining a boron atom as the central atom and conjugated systems as ligands, is presented as a route for finding alternative Li-salts for lithium-ion batteries. The properties of a wide range of novel anions designed in this way have been evaluated by DFT calculations focusing on three different fundamental success factors/measures: the strength of the cation-anion interaction, ultimately determining both the solubility and the ionic conductivity, the oxidation limit, determining their possible use vs. high voltage cathodes, and the reduction stability, revealing a possible role of the anion in the SEI-formation at the anode. For a few anions superior properties vs. today's existing or suggested anions are predicted, especially the very low cation-anion interaction strengths are promising features. The design route itself is shown to be versatile in determining the correlation between different choices of ligands and the resulting overall properties - where the most striking feature is the decreased lithium cation interaction energy upon using the (1Z,3Z)-buta-1,3-diene-1,2,3,4-tetracarbonitrile ligands. This also opens avenues for the further design of novel anions beyond those with a boron central atom.

Interferometric autocorrelation in the ultraviolet utilizing spontaneous parametric down-conversion inside an enhancement cavity.

Autocorrelation is a common method to estimate the duration of ultrashort laser pulses. In the ultraviolet (UV) regime it is challenging to employ the process of second-harmonic generation, most prominently due to absorption in nonlinear crystals at very short wavelengths. Here we show how to utilize spontaneous parametric down-conversion (SPDC) to generate an autocorrelation signal in the infrared (IR) for UV pulses. Our method utilizes the nth-order emission of the SPDC process, which occurs for low pumping powers proportional to the nth power of the UV intensity. Thus, counting 2n down-converted photons directly yields the nth-order autocorrelation. The method, now with detection of near-IR photons, is applied to the first direct measurement of ultrashort UV pulses circulating inside a UV enhancement cavity.

Pulsed laser cooling for cavity optomechanical resonators.

A pulsed cooling scheme for optomechanical systems is presented that is capable of cooling at much faster rates, shorter overall cooling times, and for a wider set of experimental scenarios than is possible by conventional methods. The proposed scheme can be implemented for both strongly and weakly coupled optomechanical systems in both weakly and highly dissipative cavities. We study analytically its underlying working mechanism, which is based on interferometric control of optomechanical interactions, and we demonstrate its efficiency with pulse sequences that are obtained by using methods from optimal control. The short time in which our scheme approaches the optomechanical ground state allows for a significant relaxation of current experimental constraints. Finally, the framework presented here can be used to create a rich variety of optomechanical interactions and hence offers a novel, readily available toolbox for fast optomechanical quantum control.

Permutationally invariant quantum tomography.

We present a scalable method for the tomography of large multiqubit quantum registers. It acquires information about the permutationally invariant part of the density operator, which is a good approximation to the true state in many relevant cases. Our method gives the best measurement strategy to minimize the experimental effort as well as the uncertainties of the reconstructed density matrix. We apply our method to the experimental tomography of a photonic four-qubit symmetric Dicke state.

Characteristics of young rural Chinese suicides: a psychological autopsy study.

BACKGROUND: Patterns of suicide rates in China differ in many ways from those in the West. This study aimed to identify the risk factors characteristic for young rural Chinese suicides. METHOD: This was a case-control psychological autopsy (PA) study. The samples were suicides and living controls (both aged 15-34 years) from 16 rural counties of China. We interviewed two informants for each suicide and each control with pretested and validated instruments to estimate psychosocial, psychiatric and other risk factors for suicides. RESULTS: The prevalence of mental disorders was higher among the young Chinese who died by suicide than among the living controls, but was lower than among suicides in the West. Marriage was not a protecting factor for suicide among young rural Chinese women, and never-married women who were involved in relationships were about three times more likely to commit suicide than single women who were unattached. Religion/religiosity was not a protecting factor in Chinese suicide, as it tended to be stronger for suicides than for controls. Impulsivity was significantly higher for suicides than for controls. Psychological strain, resulting from conflicting social values between communist gender equalitarianism and Confucian gender discrimination, was associated significantly with suicide in young rural Chinese women, even after accounting for the role of psychiatric illness. CONCLUSIONS: Risk factors for suicide in rural China are different from those in the West. Psychological strain plays a role in suicide. Suicide prevention programs in China should incorporate culture-specific considerations.

Ternary mixtures of ionic liquids for better salt solubility, conductivity and cation transference number improvement.

We hereby present the new class of ionic liquid systems in which lithium salt is introduced into the solution as a lithium cation-glyme solvate. This modification leads to the reorganisation of solution structure, which entails release of free mobile lithium cation solvate and hence leads to the significant enhancement of ionic conductivity and lithium cation transference numbers. This new approach in composing electrolytes also enables even three-fold increase of salt concentration in ionic liquids.

Differential action of (+)-amphetamine on electrically evoked dopamine overflow in rat brain slices containing corpus striatum and nucleus accumbens.

1. The effects of (+)-amphetamine on electrically evoked dopamine overflow were examined in the rat brain slice containing either anterior caudate putamen (aCPu) or nucleus accumbens (NAc), by fast cyclic voltammetry. 2. (+)-Amphetamine (1 microM) caused a time-dependent increase in the extracellular concentration of dopamine ([dopamine]ex) due to displacement of dopamine from terminal sites. After a 40 min superfusion, [dopamine]ex in the aCPu was 0.617 +/- 0.117 microM and in the NAc was 0.270 +/- 0.04 microM. Pretreatment with (-)-sulpiride (1 microM) did not affect this action of (+)-amphetamine. 3. (+)-Amphetamine (1 microM) exhibited a complex and time-dependent effect on electrically stimulated dopamine overflow, evoked by 1p, 4p/10 Hz and 20p/20 Hz. 4. In the aCPu, (+)-amphetamine (1 microM) resulted in attenuation of dopamine overflow due to 1p and 4p/10 Hz but potentiation of dopamine overflow to 20p/20 Hz. (-)-Sulpiride (1 microM) prior to (+)-amphetamine (1 microM) reversed the attenuation of dopamine overflow evoked by 1p and 4p/10 Hz but had no significant effect on dopamine overflow evoked by 20p/20 Hz. 5. (+)-Amphetamine (1 microM) potentiated dopamine overflow in the NAc to all three stimuli. (-)-Sulpiride (1 microM) prior to (+)-amphetamine (1 microM), resulted initially, in a further potentiation of overflow, followed by a time-dependent attenuation of dopamine overflow to all three stimuli. 6. t1/2, the rate of removal of [dopamine]ex following electrical stimulation was not significantly different in the aCPu and NAc for any of the stimulation conditions. After a 40 min superfusion with (+)-amphetamine (1 MicroM), t1/2 for ip, 4p/10 Hz and 20p/20 Hz was significantly increased in both the aCPuand NAc, the increase in t1/2 being significantly greater in the aCPu than in the NAc.7. In conclusion, this study indicates that the dopamine displacement and uptake inhibitory actions of(+ )-amphetamine result in complex and differential effects on electrically evoked dopamine overflow in the aCPu and NAc.

Voltammetric evidence that subsensitivity to reward following chronic mild stress is associated with increased release of mesolimbic dopamine.

Chronic exposure to mild unpredictable stress caused a decrease in rats' consumption of a palatable weak sucrose solution, which was reversed by chronic (5 weeks) administration of imipramine (5 mg/kg/day). Dopamine (DA) release in the nucleus accumbens (NAc) and caudate putamen (CPu) was measured in vivo using fast cyclic voltammetry, following electrical stimulation of the medial forebrain bundle. Experiments were performed under chloral hydrate anaesthesia 48 h after the termination of stress and the final imipramine injection. DA release was increased in the NAc of both stressed and imipramine-treated animals; imipramine did not normalize the increased DA release in stressed animals. In a further experiment, brain slices from stressed animals tended to be subsensitive to the inhibition of DA release in the NAc by quinpirole. No changes were observed in the CPu in any experiment. We discuss the relationship of these effects to stress-induced anhedonia.

A quantitative comparison on the effects of benztropine, cocaine and nomifensine on electrically evoked dopamine overflow and rate of re-uptake in the caudate putamen and nucleus accumbens in the rat brain slice.

Fast cyclic voltammetry has been used to study the relative importance of neuronal dopamine (DA) uptake and D2 autoreceptor stimulation on the control of the extracellular concentration of electrically evoked DA in rat brain slices containing aCPu and NAc. The degree of potentiation of DA overflow by benztropine, cocaine and nomifensine was always greater in the aCPu than in the NAc. Although EC50 values for the uptake blockers in the NAc were lower than in the aCPu, they were only significantly lower for 1 p with benztropine. One microM (-)-sulpiride, significantly potentiated DA overflow evoked by 20 p/20 Hz in both regions. In the presence of either 1 microM cocaine or 1 microM nomifensine, sulpiride further potentiated DA overflow in the NAc but not in the aCPu. The results indicate that in brain slices containing the aCPu, neuronal uptake is the main mechanism of controlling extracellular concentrations of DA due to electrical stimulation. Whilst in the NAc both uptake and D2 autoreceptor activation are important control mechanisms. The rate of removal of DA from the extracellular medium was not significantly different in the two regions but was decreased in the presence of (-)-sulpiride. This indicates that D2 receptors have a modulating effect on the DA neuronal uptake mechanism.

Influences of neuronal uptake and D2 autoreceptors on regulation of extracellular dopamine in the core, shell and rostral pole of the rat nucleus accumbens.

Fast cyclic voltammetry in rat brain slices containing the nucleus accumbens, was used to examine the regulation of the extracellular concentration of electrically stimulated dopamine overflow in the core, shell and rostral pole. One microM (-)-sulpiride, significantly increased dopamine overflow in all 3 regions but only when the duration of stimulation was greater than 500 ms. One microM cocaine, significantly potentiated dopamine overflow in all 3 regions following all patterns of stimulation. In the presence of 1 microM cocaine, superfusion with 1 microM (-)-sulpiride did not result in a further increase in dopamine overflow at any frequency of stimulation in the rostral pole, but significant increases in dopamine overflow were observed after stimulation with 20 pulses at 10 or 20 Hz in the core or shell; the degree of potentiation was greater in the shell than core. Quinpirole inhibited single pulse stimulated dopamine overflow in a concentration dependent manner (maximum inhibition (100%) in all regions) but was significantly less potent in the rostral pole than in the core or shell. Increasing the number of pulses to 2 or 4 pulses at 50 Hz resulted in a shift of the quinpirole dose-response curve to the right in all regions and in the rostral pole, a significant reduction in the maximum inhibition of dopamine overflow to both stimulation parameters. In the shell a significant reduction in maximum inhibition was only seen with 4 pulses at 50 Hz stimulation, whereas in the core there was no change in the maximum inhibitory effect of quinpirole. Neuronal uptake and D2 autoreceptor activity contribute to regulation of the extracellular concentration of dopamine in core, shell and rostral pole. The relative importance of either uptake or autoreceptor control is region and stimulus dependent.

Parametric analysis of the effects of cocaine and cocaine pretreatment on dopamine release in the nucleus accumbens measured by fast cyclic voltammetry.

Fast cyclic voltammetry was used to measure dopamine (DA) release in the nucleus accumbens of anaesthetized rats, in response to electrical sine-wave stimulation of the ventral tegmental area. Voltammetric signals followed increases in either frequency (50-100 Hz), intensity (50-100 microA) or duration (0.5-5.0 s) of the stimulus. Cocaine administration (10 mg/kg) preferentially increased DA release by weak electrical stimuli. Cocaine pretreatment (3 x 10 mg/kg, two weeks earlier) preferentially increased DA release by stronger stimuli, and the effects of acute cocaine were potentiated in these animals. The effects of increasing stimulus duration conformed to first order kinetics. Cocaine pretreatment selectively increased the kinetic parameter representing maximal release, while acute cocaine administration preferentially decreased the parameter representing the stimulus duration eliciting half maximal release. The lack of statistical interaction between these two effects suggests that sensitization of the response to acute cocaine by cocaine pretreatment may simply reflect an increase in the size of the releasable pool of DA.

Preliminary typology designed for treatment matching of driving-while-intoxicated offenders.

A typology of 156 convicted driving-while-intoxicated (DWI) offenders was developed using cluster analysis and external validation procedures. The typology was derived from 4 variables (alcohol dependence severity, psychiatric severity, bad-driving index, and social instability) selected to maximize the feasibility of performing treatment matching with DWI offenders. Five clusters that suggested specific treatment matching opportunities were identified. The largest, Cluster 4 (31% of cases), showed a low problem profile. However, a moderate-severity group (Cluster 1), a high-risk driver group (Cluster 2), and two high problem-severity groups (Clusters 3 and 5) were also found. Clusters 3 and 5 had high levels of alcohol dependence and psychiatric symptoms but differed significantly on social instability.

Transferrin and mitochondrial aspartate aminotransferase in young adult alcoholics.

Two recently proposed biochemical markers of alcoholism, namely, quantitation of plasma transferrin variant (Tf5.7) and the ratio of plasma mitochondrial aspartate aminotransferase (m-AspAT) to total AspAT (t-AspAT), were tested for their ability to detect young adult alcoholics. Another commonly used biochemical test, namely, activity of plasma gamma glutamyltransferase (GGT) was included as a comparison. Although mean values of GGT, TF5.7, total transferrin (Tftot), m-AspAT and t-AspAT in alcoholics were significantly higher than those in controls, there were too many overlapping values in each test between alcoholics and controls to render any of these tests suitable as a marker for young adult alcoholics. Depending on cut-off limits, the sensitivity of each test ranged from 0-52% and the specificity ranged from 80-97%. Moreover, the m-AspAT/t-AspAT and Tf5.7/Tftot ratios were not significantly different between alcoholics and controls. A stepwise linear discriminant function analysis of all the variables resulted in a slight increase in classification sensitivity (66%) but a decrease in specificity (77%). The relatively short duration (mean = 5.6 years) of heavy alcohol intake and the time elapsed (mean = 5.8 days) since the alcoholics last consumed alcohol very likely contributed to the low sensitivity. Young adults might also be more resilient with regard to the damaging biochemical effects of ethanol. Abnormal biochemical values might reverse to normal values much more quickly in young adult alcoholics than in those who are older and have more years of alcohol abuse.

Dissociation of the effects of amphetamine and quinpirole on dopamine release in the nucleus accumbens following behavioural sensitization: an ex vivo voltammetric study.

Behavioural sensitization to the locomotor stimulant effect of (+)-amphetamine or quinpirole was induced in rats by intermittent drug administration. Once established, endogenous dopamine release (DA) was measured in slices containing nucleus accumbens using fast cyclic voltammetry. DA release induced by single pulse electrical stimulation did not differ between vehicle-, (+)-amphetamine-or quinpirole-treated groups. Multiple pulse stimulation resulted in enhanced DA release in quinpirole-sensitized rats and an attenuation of DA release in (+)-amphetamine-sensitized rats. In the presence of sulpiride, DA release was increased, at low stimulation frequencies, in vehicle- and quinpirole-treated animals, but not in amphetamine-treated animals. The sensitivity of axon terminal D2 DA receptors was assessed in vitro by measuring the concentration of quinpirole required to inhibit single pulse release of DA by 50% (EC(50)). Quinpirole EC(50) was significantly increased in the quinpirole-treated animals and significantly attenuated in the (+)-amphetamine-treated animals. The results suggest that the increase in DA release following quinpirole may arise from the desensitization of release-regulating D2 autoreceptors in the nucleus accumbens. The sensitization of axon terminal D2 autoreceptors and the decrease in DA release following behavioural sensitization with (+)-amphetamine is difficult to reconcile with a unitary explanation of behavioural sensitization to both quinpirole and (+)-amphetamine. It is suggested that the effects following (+)-amphetamine may be secondary to decreased axon traffic caused by DA displacement in the ventral tegmental area, and that the drugs examined in this study may induce behavioural sensitization by different mechanisms at different sites.

New modeling methods: geographic information systems and spatial analysis.

Geographic factors, such as the location of alcohol outlets or of neighborhoods with different socioeconomic status within an area, can influence the patterns of alcohol use and alcohol-related problems in that area. Geographic information systems (GIS)--computer-based systems to capture, store, retrieve, analyze, and display spatial data--are increasingly used to investigate the effects of such geographic factors. GIS offer several key capabilities that facilitate alcohol-related geographic analyses, including geocoding (the linking of descriptive data, such as driving-while-intoxicated [DWI] events, to a location on a map), informative visual displays, and calculation of distance and adjacency. Using GIS-based data, researchers can perform complex spatial analyses of alcohol-related behaviors and problems, such as determining the correlation between DWI rates and geographic locations. These types of analyses may help investigators to understand environmental influences on alcohol-related problems and to plan and target appropriate prevention and intervention approaches.

The role of alcohol in suicides in Erie County, NY, 1972-84.

A discriminant analysis of the 806 suicide victims in Erie County, NY, from 1972-84, compared those with alcohol in the blood to those without. Thirty-three percent of the victims had alcohol in their blood. Those with blood alcohol present were more likely to demonstrate such characteristics as being male, leaving no note, being found in a vehicle, having no prior attempt, using a gun, killing themselves in the evening or at night, and not being under psychiatric treatment. The results are interpreted to mean that alcohol is a contributory cause of impulsive suicides. Suicides related to long-standing conditions, such as chronic depression or physical illness, which are less spontaneous and more predictable, are less likely to involve alcohol. The alcohol-related suicide is more likely to be impulsive. Alcohol-involved suicides reflect general drinking patterns, with men drinking more than women, and most drinking being done in the evening.

The influence of parental drinking and closeness on adolescent drinking.

OBJECTIVE: This study examines the relationship of parental drinking and adolescent's closeness to parents to adolescent drinking behavior by focusing on three related issues: (1) the independent effects of parental drinking and closeness to parents on adolescent drinking, (2) the mediating role of closeness to parents for the effect of parental drinking, and (3) their interactive effects. METHOD: The issues were addressed with use of data from 378 respondents in a random-digit dialing sample of 625 male adolescents at age range 16 to 19 in the Buffalo area. Mother's and father's drinking and adolescent's closeness to mother and father were measured separately. Regression analyses were used to assess the effects of these measures on adolescent drinking regarding the three related issues. RESULTS: Only father's drinking has a direct effect on adolescent drinking. Although closeness to mother is a significant protection against adolescent drinking, mother's drinking has no effect on closeness to mother. In contrast, father's drinking has a significant effect on closeness to father, but closeness to father has no direct effect on adolescent drinking. Therefore, there is no mediating role of closeness to parents for the effect of parental drinking. Finally, there is an interaction between mother's drinking and closeness to mother, which indicates that adolescents whose mothers are heavy drinkers and who have low closeness to their mothers drink more heavily. CONCLUSIONS: Findings suggest that for the mother and the father there are different patterns of the relationship between parental drinking and closeness at work in explaining adolescent drinking.