Localization of cold atoms in state-dependent optical lattices via a Rabi pulse

We propose a novel realization of Anderson localization in non-equilibrium states of ultracold atoms trapped in state-dependent optical lattices. The disorder potential leading to localization is generated with a Rabi pulse transfering a fraction of the atoms into a different internal state for which tunneling between lattice sites is suppressed. Atoms with zero tunneling create a quantum superposition of different random potentials, localizing the mobile atoms. We investigate the dynamics of the mobile atoms after the Rabi pulse for non-interacting and weakly interacting bosons, and we show that the evolved wavefunction attains a quasi-stationary profile with exponentially decaying tails, characteristic of Anderson localization. The localization length is seen to increase with increasing disorder and interaction strength, oppositely to what is expected for equilibrium localization.Comment: 4 pages, 4 figure

Underground bio-methanation: Concept and potential

As a major part of the energy turn around, the European Union and other countries are supporting the development of renewable energy technologies to decrease nuclear and fossil energy production. Therefore, efficient use of renewable energy resources is one challenge, as they are influenced by environmental conditions and hence, the intensity of resources such as wind or solar power fluctuates. To secure constant energy supply, suitable energy storage and conversion techniques are required. An upcoming solution is the utilization and storage of hydrogen or hydrogen-rich natural gas in porous formations in the underground. In the past, microbial methanation was observed as a side effect during these gas storage operations. The concept of underground bio-methanation arised, which uses the microbial metabolism to convert hydrogen and carbon dioxide into methane. The concept consists of injecting gaseous hydrogen and carbon dioxide into an underground structure during energy production peaks which are subsequently partly converted into methane. The resulting methane-rich gas mixture is withdrawn during high energy demand. The concept is comparable to engineered bio-reactors which are already locally integrated into the gas infrastructure. In both technologies, the conversion process of hydrogen into methane is driven by hydrogenotrophic methanogenic archaea present in the aqueous phase of the natural underground or above-ground engineered reactor. Nevertheless, the porous medium in the underground provides, compared to the engineered bio-reactors, a larger interface between the gas and aqueous phase caused by the enormous volume in the underground porous media. The following article summarizes the potential and concept of underground methanation and the current state of the art in terms of laboratory investigations and pilot tests. A short system potential analysis shows that an underground bio-reactor with a storage capacity of 850 Mio. Sm could deliver methane to more than 600,000 households, based on a hydrogen production from renewable energies

The regulation of cytokine networks in hippocampal CA1 differentiates extinction from those required for the maintenance of contextual fear memory after recall

We investigated the distinctiveness of gene regulatory networks in CA1 associated with the extinction of contextual fear memory (CFM) after recall using Affymetrix GeneChip Rat Genome 230 2.0 Arrays. These data were compared to previously published retrieval and reconsolidation-attributed, and consolidation datasets. A stringent dual normalization and pareto-scaled orthogonal partial least-square discriminant multivariate analysis together with a jack-knifing-based cross-validation approach was used on all datasets to reduce false positives. Consolidation, retrieval and extinction were correlated with distinct patterns of gene expression 2 hours later. Extinction-related gene expression was most distinct from the profile accompanying consolidation. A highly specific feature was the discrete regulation of neuroimmunological gene expression associated with retrieval and extinction. Immunity–associated genes of the tyrosine kinase receptor TGFβ and PDGF, and TNF families’ characterized extinction. Cytokines and proinflammatory interleukins of the IL-1 and IL-6 families were enriched with the no-extinction retrieval condition. We used comparative genomics to predict transcription factor binding sites in proximal promoter regions of the retrieval-regulated genes. Retrieval that does not lead to extinction was associated with NF-κB-mediated gene expression. We confirmed differential NF-κBp65 expression, and activity in all of a representative sample of our candidate genes in the no-extinction condition. The differential regulation of cytokine networks after the acquisition and retrieval of CFM identifies the important contribution that neuroimmune signalling plays in normal hippocampal function. Further, targeting cytokine signalling upon retrieval offers a therapeutic strategy to promote extinction mechanisms in human disorders characterised by dysregulation of associative memory

Emotion regulation in patients with rheumatic diseases: validity and responsiveness of the Emotional Approach Coping Scale (EAC)

Background Chronic rheumatic diseases are painful conditions which are not entirely controllable and can place high emotional demands on individuals. Increasing evidence has shown that emotion regulation in terms of actively processing and expressing disease-related emotions are likely to promote positive adjustment in patients with chronic diseases. The Emotional Approach Coping Scale (EAC) measures active attempts to acknowledge, understand, and express emotions. Although tested in other clinical samples, the EAC has not been validated for patients with rheumatic diseases. This study evaluated the data quality, internal consistency reliability, validity and responsiveness of the Norwegian version of the EAC for this group of patients. Methods 220 patients with different rheumatic diseases were included in a cross-sectional study in which data quality and internal consistency were assessed. Construct validity was assessed through comparisons with the Brief Approach/Avoidance Coping Questionnaire (BACQ) and the General Health Questionnaire (GHQ-20). Responsiveness was tested in a longitudinal pretest-posttest study of two different coping interventions, the Vitality Training Program (VTP) and a Self-Management Program (SMP). Results The EAC had low levels of missing data. Results from principal component analysis supported two subscales, Emotional Expression and Emotional Processing, which had high Cronbach's alphas of 0.90 and 0.92, respectively. The EAC had correlations with approach-oriented items in the BACQ in the range 0.17-0.50. The EAC Expression scale had a significant negative correlation with the GHQ-20 of -0.13. As hypothesized, participation in the VTP significantly improved EAC scores, indicating responsiveness to change. Conclusion The EAC is an acceptable and valid instrument for measuring emotional processing and expression in patients with rheumatic diseases. The EAC scales were responsive to change in an intervention designed to promote emotion regulation. The instrument has not yet been tested for test-retest reliability, which is recommended in future studies

Improved vanillin production in baker's yeast through in silico design

<p>Abstract</p> <p>Background</p> <p>Vanillin is one of the most widely used flavouring agents, originally obtained from cured seed pods of the vanilla orchid <it>Vanilla planifolia</it>. Currently vanillin is mostly produced <it>via </it>chemical synthesis. A <it>de novo </it>synthetic pathway for heterologous vanillin production from glucose has recently been implemented in baker's yeast, <it>Saccharamyces cerevisiae</it>. In this study we aimed at engineering this vanillin cell factory towards improved productivity and thereby at developing an attractive alternative to chemical synthesis.</p> <p>Results</p> <p>Expression of a glycosyltransferase from <it>Arabidopsis thaliana </it>in the vanillin producing <it>S. cerevisiae </it>strain served to decrease product toxicity. An <it>in silico </it>metabolic engineering strategy of this vanillin glucoside producing strain was designed using a set of stoichiometric modelling tools applied to the yeast genome-scale metabolic network. Two targets (<it>PDC1 </it>and <it>GDH1</it>) were selected for experimental verification resulting in four engineered strains. Three of the mutants showed up to 1.5 fold higher vanillin β-D-glucoside yield in batch mode, while continuous culture of the <it>Δpdc1 </it>mutant showed a 2-fold productivity improvement. This mutant presented a 5-fold improvement in free vanillin production compared to the previous work on <it>de novo </it>vanillin biosynthesis in baker's yeast.</p> <p>Conclusion</p> <p>Use of constraints corresponding to different physiological states was found to greatly influence the target predictions given minimization of metabolic adjustment (MOMA) as biological objective function. <it>In vivo </it>verification of the targets, selected based on their predicted metabolic adjustment, successfully led to overproducing strains. Overall, we propose and demonstrate a framework for <it>in silico </it>design and target selection for improving microbial cell factories.</p

Correlations in Ising chains with non-integrable interactions

Two-spin correlations generated by interactions which decay with distance r as r^{-1-sigma} with -1 <sigma <0 are calculated for periodic Ising chains of length L. Mean-field theory indicates that the correlations, C(r,L), diminish in the thermodynamic limit L -> \infty, but they contain a singular structure for r/L -> 0 which can be observed by introducing magnified correlations, LC(r,L)-\sum_r C(r,L). The magnified correlations are shown to have a scaling form F(r/L) and the singular structure of F(x) for x->0 is found to be the same at all temperatures including the critical point. These conclusions are supported by the results of Monte Carlo simulations for systems with sigma =-0.50 and -0.25 both at the critical temperature T=Tc and at T=2Tc.Comment: 13 pages, latex, 5 eps figures in a separate uuencoded file, to appear in Phys.Rev.

Delphi Study to Reach International Consensus Among Vascular Surgeons on Major Arterial Vascular Surgical Complications

Background: The complications discussed with patients by surgeons prior to surgery vary, because no consensus on major complications exists. Such consensus may improve informed consent and shared decision-making. This study aimed to achieve consensus among vascular surgeons on which complications are considered ‘major’ and which ‘minor,’ following surgery for abdominal aortic aneurysm (AAA), carotid artery disease (CAD) and peripheral artery disease (PAD). Methods: Complications following vascular surgery were extracted from Cochrane reviews, national guidelines, and reporting standards. Vascular surgeons from Europe and North America rated complications as major or minor on five-point Likert scales via an electronic Delphi method. Consensus was reached if ≥ 80% of participants scored 1 or 2 (minor) or 4 or 5 (major). Results: Participants reached consensus on 9–12 major and 6–10 minor complications per disease. Myocardial infarction, stroke, renal failure and allergic reactions were considered to be major complications of all three diseases. All other major complications were treatment specific or dependent on disease severity, e.g., spinal cord ischemia, rupture following AAA repair, stroke for CAD or deep wound infection for PAD. Conclusion: Vascular surgeons reached international consensus on major and minor complications following AAA, CAD and PAD treatment. This consensus may be helpful in harmonizing the information patients receive and improving standardization of the informed consent procedure. Since major complications differed between diseases, consensus on disease-specific complications to be discussed with patients is necessary

Specialised tools are needed when searching the web for rare disease diagnoses

In our recent paper, we study web search as an aid in the process of diagnosing rare diseases. To answer the question of how well Google Search and PubMed perform, we created an evaluation framework with 56 diagnostic cases and made our own specialized search engine, FindZebra (findzebra.com). FindZebra uses a set of publicly available curated sources on rare diseases and an open-source information retrieval system, Indri. Our evaluation and the feedback received after the publication of our paper both show that FindZebra outperforms Google Search and PubMed. In this paper, we summarize the original findings and the response to FindZebra, discuss why Google Search is not designed for specialized tasks and outline some of the current trends in using web resources and social media for medical diagnosis

FindZebra:a search engine for rare diseases

BACKGROUND: The web has become a primary information resource about illnesses and treatments for both medical and non-medical users. Standard web search is by far the most common interface to this information. It is therefore of interest to find out how well web search engines work for diagnostic queries and what factors contribute to successes and failures. Among diseases, rare (or orphan) diseases represent an especially challenging and thus interesting class to diagnose as each is rare, diverse in symptoms and usually has scattered resources associated with it. METHODS: We design an evaluation approach for web search engines for rare disease diagnosis which includes 56 real life diagnostic cases, performance measures, information resources and guidelines for customising Google Search to this task. In addition, we introduce FindZebra, a specialized (vertical) rare disease search engine. FindZebra is powered by open source search technology and uses curated freely available online medical information. RESULTS: FindZebra outperforms Google Search in both default set-up and customised to the resources used by FindZebra. We extend FindZebra with specialized functionalities exploiting medical ontological information and UMLS medical concepts to demonstrate different ways of displaying the retrieved results to medical experts. CONCLUSIONS: Our results indicate that a specialized search engine can improve the diagnostic quality without compromising the ease of use of the currently widely popular standard web search. The proposed evaluation approach can be valuable for future development and benchmarking. The FindZebra search engine is available at http://www.findzebra.com/