Scaling of the Kondo zero bias peak in a hole quantum dot at finite temperatures

We have measured the zero bias peak in differential conductance in a hole quantum dot. We have scaled the experimental data with applied bias and compared to real time renormalization group calculations of the differential conductance as a function of source-drain bias in the limit of zero temperature and at finite temperatures. The experimental data show deviations from the T=0 calculations at low bias, but are in very good agreement with the finite T calculations. The Kondo temperature T_K extracted from the data using T=0 calculations, and from the peak width at 2/3 maximum, is significantly higher than that obtained from finite T calculations.Comment: Accepted to Phys. Rev. B (Rapid

The challenging optics of XtremeD – a neutron diffractometer for high pressures and magnetic fields at ILL developed by Spain

6 páginas, 3 figuras.The Spanish community of neutron scatterers and the ILL are considering the construction of a CRG "extreme conditions Diffractometer (XtremeD)" for both single crystals and powders, operating at high pressures (up to 50 GPa) and high magnetic fields (up to 15 Tesla). High pressure studies require reduced sample volumes. This makes the focusing optics a crucial part of the instrument, in order to have increased flux and to avoid the scattering from the sample environment. The different solutions at different levels of the instrument, which are being studied, will be discussed in this paper.Peer reviewe

Sex Specific Changes in Tryptophan Breakdown Over a 6 Week Treatment Period

Introduction: Despite the knowledge of sex differences concerning neurobiological parameters as well as clinical course of illness in individuals with mood disorders, the literature concerning tryptophan (Trp) breakdown, specific for women and men, is sparse to date. The current study aimed to evaluate sex differences in Trp, kynurenine (Kyn) and Kyn/Trp concentrations in general, as well as differences in changes of those concentrations over the course of a 6-week rehabilitation program in individuals with life-time unipolar affective disorder. For this purpose changes in Trp and Kyn as well as the Kyn/Trp concentrations between the time of admission (t1) and discharge (t2) were analyzed in dependence of sex. Furthermore, correlations between Trp and Kyn levels and clinical parameters were performed separately for male and female participants.Material and Methods:Results: For the current analysis 426 individuals with lifetime affective disorder completing a 6-week rehabilitation program were included. In both sexes, psychiatric symptoms decreased significantly over time. There was a significant difference between women (n = 242) and men (n = 184) regarding the changes in Trp, Kyn, and Kyn/Trp over time even if controlled for relevant covariates [multivariate: F(3, 380) = 2.663, η2 = 0.021, p = 0.048]. Kyn as well as Kyn/Trp concentrations increased significantly in men over time (Kyn F = 4.809, η2 = 0.012, p = 0.029; Kyn/Trp F = 7.923, η2 = 0.020, p = 0.005). Results remained the same when controlled for psychiatric symptoms.Discussion: The main finding of the present study is the significant difference between women and men regarding the change in Trp, Kyn, and Kyn/Trp over a 6-week psychiatric treatment period, while the depression severity scores as well as general psychiatric symptoms decreased. Sex specific changes in Trp-Kyn pathways have only been explored to a very small extent to date in the literature but are of high clinical relevance in the context of personalized medicine

Psychopathic personality traits stress immunity and social potency moderate the relationship between emotional competence and cognitive functions in depression

BackgroundPsychopathic personality traits (PPT) and depression have both been shown to worsen emotional and cognitive functions. Moreover, PPT and depression share similar underlying neuronal circuits tapping into the emotional and cognitive domains. However, little is known about the influence of PPT on emotion and cognition in individuals with depression.ObjectivesThis study aimed to examine the correlative relationships and moderating role of PPT in the association between emotional competence and cognitive functions in individuals with depression.MethodsData from 373 individuals diagnosed with depression (158 males, 215 females) were examined within a cohort study. Subjects filled out validated questionnaires surveying PPT and emotional competences. Furthermore, a comprehensive neuropsychological test battery was administered.ResultsCorrelation analyses revealed a significant positive association between emotional competence and cognitive functions. Further, negative associations between emotional competence and the PPT “Blame Externalisation” and “Careless Nonplanfulness,” as well as positive associations with psychopathic “Social Potency” and “Stress Immunity” were found. Moderation analyses indicated a significant positive influence of psychopathic “Stress Immunity” and “Social Influence” on the relationship between emotional competence and cognitive functions.ConclusionThe findings highlight the importance of integrating PPT in depression research. Considering PPT in depression treatment could also facilitate the therapeutic process by identifying individual traits as resilience-strengthening or potentially harmful factors for depressive symptomatology. This study represents a stepping stone for further research regarding the role of personality traits in psychiatric disorders and their treatment

Patient-reported outcome data generated in a clinical intervention in community mental health care - psychometric properties

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

Indoleamine 2,3-dioxygenase (IDO)-activity in severe psychiatric disorders: A systemic review

Indoleamine 2,3-dioxygenase (IDO) activity is induced by cellular immune activation and therefore associated to inflammatory diseases, among others psychiatric disorders. This review aims to elucidate IDO activity reflected by kynurenine (KYN) to tryptophan (TRP) ratio in severe mental disorders

Psychometric precision in phenotype definition is a useful step in molecular genetic investigation of psychiatric disorders

Affective disorders are highly heritable, but few genetic risk variants have been consistently replicated in molecular genetic association studies. The common method of defining psychiatric phenotypes in molecular genetic research is either a summation of symptom scores or binary threshold score representing the risk of diagnosis. Psychometric latent variable methods can improve the precision of psychiatric phenotypes, especially when the data structure is not straightforward. Using data from the British 1946 birth cohort, we compared summary scores with psychometric modeling based on the General Health Questionnaire (GHQ-28) scale for affective symptoms in an association analysis of 27 candidate genes (249 single-nucleotide polymorphisms (SNPs)). The psychometric method utilized a bi-factor model that partitioned the phenotype variances into five orthogonal latent variable factors, in accordance with the multidimensional data structure of the GHQ-28 involving somatic, social, anxiety and depression domains. Results showed that, compared with the summation approach, the affective symptoms defined by the bi-factor psychometric model had a higher number of associated SNPs of larger effect sizes. These results suggest that psychometrically defined mental health phenotypes can reflect the dimensions of complex phenotypes better than summation scores, and therefore offer a useful approach in genetic association investigations

Changes in tryptophan breakdown associated with response to multimodal treatment in depression

BackgroundResearch on depression showed that dysregulations in tryptophan (TRP), kynurenine (KYN), and its KYN pathway metabolites are key aspects in the development and maintenance of depressive symptoms. In our previous reports, we described sex-specific changes in TRP breakdown as well as changes in KYN and KYN/TRP in association with treatment response and inflammatory and metabolic parameters. However, results of treatment effects on KYN pathway metabolites as well as how pathway changes are related to treatment response remain sparse.ObjectiveWe investigated potential changes of KYN and KYN pathway metabolites in association with therapeutic response of individuals with depression during a six-week multimodal psychiatric rehabilitation program.Methods87 participants were divided into treatment responders and non-responders (48 responders, 39 non-responders; 38 male, 49 female; Mage = 51.09; SDage = 7.70) using scores of psychological questionnaires. KYN pathway metabolites serum concentrations as well as their ratios were collected using high performance liquid chromatography. Changes over time (time of admission (t1) vs. time of discharge (t2)) were calculated using repeated measure analyses of (co)variance.ResultsNon-responders exhibited higher levels of 3-Hydroxyanthralinic acid (3-HAA), nicotinic acid (NA), and 3-HAA/KYN, independently of measurement time. NA levels decreased, while 3-HAA levels increased over time in both groups, independently of treatment response. 3-HK/KYN levels decreased, while KYN levels increased in non-responders, but not in responders over time.DiscussionThe results indicate that some compounds of the KYN pathway metabolites can be altered through multimodal long-term interventions in association with treatment response. Especially the pathway degrading KYN further down to 3-HAA and 3-HK/KYN might be decisive for treatment response in depression