Creating mirror-mirror quantum correlations in optomechanics

We study the transfer of quantum correlations between two movable mirrors of two Fabry-P\'erot cavities separated via broadband squeezed light and coupled via photon hopping process. We investigate the transfer of quantum correlations from EPR entangled squeezed light to the movable mirrors. We show that Gaussian quantum steering remains lower than entanglement. We employ Gaussian quantum steering to characterize the steerability between the two mechanical modes. The logarithmic negativity is used as the witness of quantum entanglement and Gaussian quantum discord gives the measure of all non classical correlations including entanglement. We conclude that the transfer of quantum correlations is optimal for a strong optomechanical coupling and decreases with the thermal effects. We also conclude that steering, entanglement and discord are directly related to photon hopping coupling and the squeezing parameter

On the harmonic superspace language adapted to the Gelfand-Dickey algebra of differential operators

Methods developed for the analysis of non-linear integrable models are used in the harmonic superspace (HS) framework. These methods, when applied to the HS, can lead to extract more information about the meaning of integrability in non-linear physical problems. Among the results obtained, we give the basic ingredients towards building in the HS language the analogue of the G.D. algebra of pseudo-differential operators. Some useful convention notations and algebraic structures are also introduced to make the use of the harmonic superspace techniques more accessible.Comment: 14 page

On the Fairlie's Moyal formulation of M(atrix)- theory

Starting from the Moyal formulation of M-theory in the large N-limit, we propose to reexamine the associated membrane equations of motion in 10 dimensions formulated in terms of Poisson bracket. Among the results obtained, we rewrite the coupled first order Nahm's equations into a simple form leading in turn to their systematic relation with $SU(\infty)$ Yang Mills equations of motion. The former are interpreted as the vanishing condition of some conserved currents which we propose. We develop also an algebraic analysis in which an ansatz is considered and find an explicit form for the membrane solution of our problem. Typical solutions known in literature can also emerge as special cases of the proposed solutionComment: 16 page

MR defecography: A diagnostic test for the evaluation of pelvic floor motion in patients with dyssynergic defecation after biofeedback therapy

Background: Dyssynergic defecation is a major cause of chronic functional constipation as a common digestive complaint. We clinically evaluated the effects of biofeedback therapy on the pelvic floor motion indices through magnetic resonance (MR) defecography, quality of life and depression in patients with dyssynergic defecation. Methods: In this clinical trial study, among patients referring to the Colorectal Clinic of Hazrat Rasoul Hospital, 22 subjects were randomly assigned into two equal groups (n= 11) to receive either standard only or biofeedback and standard therapy. Dynamic changes of the pelvic floor were measured by MR defecography. During the simulated defecation, two MR defecography dynamic indices including abnormal anorectal angle change and perineal descent were measured before and after treatment. The effects of biofeedback therapy on patients' symptoms, quality of life and severity of depression were assessed and compared with the standard therapy. Statistical analysis was carried out using independent t-test and Mann-Whitney test. Results: Paradox index (p< 0.001), perineal descent index (p< 0.001), depression (p< 0.1), physical function (p< 0.001), vitality (p< 0.001) and role emotion (p< 0.001) significantly improved in the biofeedback therapy group in contrast to the standard therapy SDT group. Conclusion: Biofeedback therapy appears to be effective in improving symptoms of functional constipation and dysfunction of pelvic floor motion as well as patient's quality of life and depression state. MR defecography is able to show the changes in dynamic indices of the pelvic floor through biofeedback therapy

Robust RT-qPCR Data Normalization: Validation and Selection of Internal Reference Genes during Post-Experimental Data Analysis

Reverse transcription and real-time PCR (RT-qPCR) has been widely used for rapid quantification of relative gene expression. To offset technical confounding variations, stably-expressed internal reference genes are measured simultaneously along with target genes for data normalization. Statistic methods have been developed for reference validation; however normalization of RT-qPCR data still remains arbitrary due to pre-experimental determination of particular reference genes. To establish a method for determination of the most stable normalizing factor (NF) across samples for robust data normalization, we measured the expression of 20 candidate reference genes and 7 target genes in 15 Drosophila head cDNA samples using RT-qPCR. The 20 reference genes exhibit sample-specific variation in their expression stability. Unexpectedly the NF variation across samples does not exhibit a continuous decrease with pairwise inclusion of more reference genes, suggesting that either too few or too many reference genes may detriment the robustness of data normalization. The optimal number of reference genes predicted by the minimal and most stable NF variation differs greatly from 1 to more than 10 based on particular sample sets. We also found that GstD1, InR and Hsp70 expression exhibits an age-dependent increase in fly heads; however their relative expression levels are significantly affected by NF using different numbers of reference genes. Due to highly dependent on actual data, RT-qPCR reference genes thus have to be validated and selected at post-experimental data analysis stage rather than by pre-experimental determination

Evaluation of Candidate Reference Genes for Gene Expression Normalization in Brassica juncea Using Real Time Quantitative RT-PCR

The real time quantitative reverse transcription PCR (qRT-PCR) is becoming increasingly important to gain insight into function of genes. Given the increased sensitivity, ease and reproducibility of qRT-PCR, the requirement of suitable reference genes for normalization has become important and stringent. It is now known that the expression of internal control genes in living organism vary considerably during developmental stages and under different experimental conditions. For economically important Brassica crops, only a couple of reference genes are reported till date. In this study, expression stability of 12 candidate reference genes including ACT2, ELFA, GAPDH, TUA, UBQ9 (traditional housekeeping genes), ACP, CAC, SNF, TIPS-41, TMD, TSB and ZNF (new candidate reference genes), in a diverse set of 49 tissue samples representing different developmental stages, stress and hormone treated conditions and cultivars of Brassica juncea has been validated. For the normalization of vegetative stages the ELFA, ACT2, CAC and TIPS-41 combination would be appropriate whereas TIPS-41 along with CAC would be suitable for normalization of reproductive stages. A combination of GAPDH, TUA, TIPS-41 and CAC were identified as the most suitable reference genes for total developmental stages. In various stress and hormone treated samples, UBQ9 and TIPS-41 had the most stable expression. Across five cultivars of B. juncea, the expression of CAC and TIPS-41 did not vary significantly and were identified as the most stably expressed reference genes. This study provides comprehensive information that the new reference genes selected herein performed better than the traditional housekeeping genes. The selection of most suitable reference genes depends on the experimental conditions, and is tissue and cultivar-specific. Further, to attain accuracy in the results more than one reference genes are necessary for normalization