Observation of subdiffusion of a disordered interacting system

We study the transport dynamics of matter-waves in the presence of disorder and nonlinearity. An atomic Bose-Einstein condensate that is localized in a quasiperiodic lattice in the absence of atom-atom interaction shows instead a slow expansion with a subdiffusive behavior when a controlled repulsive interaction is added. The measured features of the subdiffusion are compared to numerical simulations and a heuristic model. The observations confirm the nature of subdiffusion as interaction-assisted hopping between localized states and highlight a role of the spatial correlation of the disorder.Comment: 8 pages, to be published on Physical Review Letter

Relationships among classifications of ayurvedic medicine diagnostics for imbalances and western measures of psychological states: An exploratory study.

BackgroundAccording to Ayurveda, the traditional medical system of India, doshas are a combination of characteristics based on a five-element philosophy that drive our mental and physical tendencies. When the doshas, or functional principles, are out of balance in quality or quantity, wellbeing is adversely affected and symptoms manifest.ObjectiveThis study examined relationships among imbalances in the doshas (termed Vikruti) reported via questionnaire and Western measures of psychological states.Materials and methodsStudy participants were 101 women (n = 81) and men (n = 20), mean age 53.9 years (SD = 11.7; range 32-80). Participants completed questionnaires to categorize their Vikruti type and psychological states, which included depressed mood (CESD), anxiety (PROMIS), rumination & reflection (RRQ), mindfulness (MAAS), stress (PSS), and quality of life (Ryff).ResultsMultivariate general linear modeling, controlling for age, gender and body mass index (BMI), showed that Vata imbalance was associated with more anxiety (p ≤ 0.05), more rumination (p ≤ 0.01), less mindfulness (p ≤ 0.05), and lower overall quality of life (p ≤ 0.01). Pitta imbalance was associated with poorer mood (p ≤ 0.01) and less mindfulness (p ≤ 0.05), more anxiety (p ≤ 0.05) and stress (p ≤ 0.05). Kapha imbalance was associated with more stress (p ≤ 0.05), more rumination (p ≤ 0.05) and less reflection (p ≤ 0.05).ConclusionThese findings suggest that symptoms of mind-body imbalances in Ayurveda are differentially associated with western assessments of psychological states. Ayurvedic dosha assessment may be an effective way to assess physical as well as emotional wellbeing in research and clinical settings

A γ-secretase inhibitor, but not a γ-secretase modulator, induced defects in BDNF axonal trafficking and signaling: evidence for a role for APP.

Clues to Alzheimer disease (AD) pathogenesis come from a variety of different sources including studies of clinical and neuropathological features, biomarkers, genomics and animal and cellular models. An important role for amyloid precursor protein (APP) and its processing has emerged and considerable interest has been directed at the hypothesis that Aβ peptides induce changes central to pathogenesis. Accordingly, molecules that reduce the levels of Aβ peptides have been discovered such as γ-secretase inhibitors (GSIs) and modulators (GSMs). GSIs and GSMs reduce Aβ levels through very different mechanisms. However, GSIs, but not GSMs, markedly increase the levels of APP CTFs that are increasingly viewed as disrupting neuronal function. Here, we evaluated the effects of GSIs and GSMs on a number of neuronal phenotypes possibly relevant to their use in treatment of AD. We report that GSI disrupted retrograde axonal trafficking of brain-derived neurotrophic factor (BDNF), suppressed BDNF-induced downstream signaling pathways and induced changes in the distribution within neuronal processes of mitochondria and synaptic vesicles. In contrast, treatment with a novel class of GSMs had no significant effect on these measures. Since knockdown of APP by specific siRNA prevented GSI-induced changes in BDNF axonal trafficking and signaling, we concluded that GSI effects on APP processing were responsible, at least in part, for BDNF trafficking and signaling deficits. Our findings argue that with respect to anti-amyloid treatments, even an APP-specific GSI may have deleterious effects and GSMs may serve as a better alternative

Long-Range Correlations and Natural Time Series Analyses from Acoustic Emission Signals

This work focuses on analyzing acoustic emission (AE) signals as a means to predict failure in structures. There are two main approaches that are considered: (i) long-range correlation analysis using both the Hurst (H) and the detrended fluctuation analysis (DFA) exponents, and (ii) natural time domain (NT) analysis. These methodologies are applied to the data that were collected from two application examples: a glass fiber-reinforced polymeric plate and a spaghetti bridge model, where both structures were subjected to increasing loads until collapse. A traditional (AE) signal analysis was also performed to reference the study of the other methods. The results indicate that the proposed methods yield reliable indication of failure in the studied structures

CALCIUM RESPONSES IN FIBROBLASTS FROM ASYMPTOMATIC MEMBERS OF ALZHEIMER'S DISEASE FAMILIES

Abstract We have previously identified alterations of K + channel function, IP 3 -mediated calcium release, and Cp20 (a memory-associated GTP binding protein) in fibroblasts from Alzheimer's disease (AD) patients vs controls. Some of these alterations can be integrated into an index that distinguishes AD patients from controls with both high specificity and high sensitivity. We report here that alterations in IP 3 -mediated calcium responses are present in a large proportion of AD family members (i.e., individuals at high risk) before clinical symptoms of Alzheimer's disease are present. This was not the case if such members later "escaped" AD symptoms. This preclinical calcium signal correlate of later AD does not reflect, however, the presence of the PS1 familial AD gene

BeppoSAX Observations of the TeV Blazar Mkn 421

The blazar Mkn 421 has been observed, as part of the AO1 Core Program, five times from 2 to 7 May 1997. In the LECS+MECS energy band the spectrum shows convex curvature, well represented by a broken power--law. Flux variability (more than a factor 2) has been detected over the entire 0.1--10 keV range, accompanying which the spectrum steepens with the decrease in intensity. Mkn 421 has also been detected with the PDS instrument. Our preliminary analysis indicates that the PDS spectrum lies significantly above the extrapolation from the MECS, suggesting a contribution from a flatter high energy component.Comment: 4 pages, 4 Postscript figures, uses espcrc2.sty and psfig.sty (both included). To appear in "The Active X-ray Sky: Results from BeppoSAX and Rossi-XTE", Rome, Italy, 21-24 October, 1997. Eds.: L. Scarsi, H. Bradt, P. Giommi and F. Fior

Correlation function of weakly interacting bosons in a disordered lattice

One of the most important issues in disordered systems is the interplay of the disorder and repulsive interactions. Several recent experimental advances on this topic have been made with ultracold atoms, in particular the observation of Anderson localization, and the realization of the disordered Bose-Hubbard model. There are however still questions as to how to differentiate the complex insulating phases resulting from this interplay, and how to measure the size of the superfluid fragments that these phases entail. It has been suggested that the correlation function of such a system can give new insights, but so far little experimental investigation has been performed. Here, we show the first experimental analysis of the correlation function for a weakly interacting, bosonic system in a quasiperiodic lattice. We observe an increase in the correlation length as well as a change in shape of the correlation function in the delocalization crossover from Anderson glass to coherent, extended state. In between, the experiment indicates the formation of progressively larger coherent fragments, consistent with a fragmented BEC, or Bose glass.Comment: 16 pages, 8 figure