406 research outputs found
Nonlinear Filtering of Classical and Quantum Spin Systems
In this paper we consider classical and quantum spin systems on discrete
lattices and in Euclidean spaces, modeled by infinite dimensional stochastic
diffusions in Hilbert spaces. Existence and uniqueness of various notions of
solutions, existence and uniqueness of invariant measures as well as
exponential convergence to equilibrium are known for these models. We formulate
nonlinear filtering problem for these classes of models, derive nonlinear
filtering equations of Fujisaki-Kallianpur-Kunita and Zakai tye, and prove
existence and uniqueness of measure-valued solutions to these filtering
equations. We then establish the Feller property and Markov property of the
semigroups associated with the filtering equations and also prove existence and
uniqueness of invariant measures. Evolution of error covariance equation for
the nonlinear filter is derived. We also derive the nonlinear filtering
equations associated with finitely-additive white noise formulation due to
Kallianpur and Karandikar for the classical and quantum spin systems, and study
existence and uniqueness of measure-valued solution
Androgen-responsive non-coding small RNAs extend the potential of HCG stimulation to act as a bioassay of androgen sufficiency
Background: It is unclear whether a short-term change in circulating androgens is associated with changes in the transcriptome of the peripheral blood mononuclear cells (PBMC).
Aims & Methods: To explore the effect of hCG-stimulation on the PBMC-transcriptome, 12 boys with a median age (range) of 0.7yrs (0.3, 11.2) who received intramuscular hCG 1500u on 3 consecutive days as part of their investigations underwent transcriptomic array analysis on RNA extracted from peripheral blood mononuclear cells before and after hCG stimulation.
Results: Median pre and post hCG testosterone for the overall group was 0.7nmol/l (<0.5,6) and 7.9nmol/l (<0.5, 31.5), respectively. Of the 12 boys, 3 (25%) did not respond to hCG stimulation with a pre and post median serum testosterone of <0.5nmol/l and <0.5nmol/l, respectively. When corrected for gene expression changes in the non-responders to exclude hCG effects, all 9 of the hCG responders consistently demonstrated a 20% or greater increase in the expression of piR-37153 and piR-39248, non-coding PIWI-interacting RNAs (piRNAs). In addition, of the 9 responders, 8, 6 and 4 demonstrated a 30%, 40% and 50% rise, respectively in a total of 2 further piRNAs. In addition, 3 of the responders showed a 50% or greater rise in the expression of another small RNA, SNORD5. On comparing fold change in serum testosterone with fold change in the above transcripts, a positive correlation was detected for SNORD5 (p=0.01).
Conclusions: The identification of a dynamic and androgen-responsive PBMC-transcriptome extends the potential value of the hCG test for assessment of androgen sufficiency
Quantitative proteomics in resected renal cancer tissue for biomarker discovery and profiling
<b>Background:</b>Â Â Proteomics-based approaches for biomarker discovery are promising strategies used in cancer research. We present state-of-art label-free quantitative proteomics method to assess proteome of renal cell carcinoma (RCC) compared with noncancer renal tissues.<p></p>
<b>Methods:</b>Â Â Fresh frozen tissue samples from eight primary RCC lesions and autologous adjacent normal renal tissues were obtained from surgically resected tumour-bearing kidneys. Proteins were extracted by complete solubilisation of tissues using filter-aided sample preparation (FASP) method. Trypsin digested proteins were analysed using quantitative label-free proteomics approach followed by data interpretation and pathways analysis.<p></p>
<b>Results:</b>Â Â A total of 1761 proteins were identified and quantified with high confidence (MASCOT ion score threshold of 35 and P-value <0.05). Of these, 596 proteins were identified as differentially expressed between cancer and noncancer tissues. Two upregulated proteins in tumour samples (adipose differentiation-related protein and Coronin 1A) were further validated by immunohistochemistry. Pathway analysis using IPA, KOBAS 2.0, DAVID functional annotation and FLink tools showed enrichment of many cancer-related biological processes and pathways such as oxidative phosphorylation, glycolysis and amino acid synthetic pathways.<p></p>
<b>Conclusions:<b>Â Â Our study identified a number of differentially expressed proteins and pathways using label-free proteomics approach in RCC compared with normal tissue samples. Two proteins validated in this study are the focus of on-going research in a large cohort of patients.<p></p>
Kinetics and spectral properties of electron and <SUP>•</SUP>OH adducts of dimethylpyridines: a pulse radiolysis study
The reactions of e-aq, •OH•-, O•- and SO•-4 with 2,4-, 2,6- and 3,5-dimethylpyridines have been investigated in aqueous solution by pulse radiolysis with optical detection. Both e-aq and •OH radicals have high reactivity toward these compounds with k = 4-8×109 dm3 mol-1 s-1. The rates of O• and SO•-4 reactions (1-3 × 109 dm3 mol-1 s-1 were lower compared to the rate observed with the •OH radical. The transient absorption spectra obtained in the reaction of e-aq with three isomers exhibited a weak broad band around 340-410 nm. The absorption maxima of the intermediates formed in the •OH and SO•-4 reactions were centred around 320-330 nm (ε= 2450- 3500 dm3 mol-1 cm-1/ with an additional broad peak in the range 460-520 nm which are attributed to the corresponding •OH adducts. The spectra in the O•- reaction have absorption maxima between 300 and 320 nm and it reacts both by addition and H-abstraction from the CH3 group. A reaction mechanism consistent with the observed results is proposed
Detection of 65 kD heat shock protein in cerebrospinal fluid of tuberculous meningitis patients
BACKGROUND: Diagnosis of tuberculous meningitis (TBM) is difficult. Rapid confirmatory diagnosis is essential to initiate required therapy. There are very few published reports about the diagnostic significance of 65 kD heat shock protein (hsp) in TBM patients, which is present in a wide range of Mycobacterium tuberculosis species and elicits a cellular and humoral immune response. In the present study we have conducted a prospective evaluation for the demonstration of 65 kD hsp antigen in cerebrospinal fluid (CSF) of TBM patients, by indirect ELISA method using monoclonal antibodies (mAb) against the 65 kD hsp antigen, for the diagnosis of TBM. METHODS: A total of 160 CSF samples of different groups of patients (confirmed TBM {n = 18}, clinically suspected TBM {n = 62}, non TBM infectious meningitis {n = 35} and non-infectious neurological diseases {n = 45}) were analyzed by indirect ELISA method using mAb to 65 kD hsp antigen. The Kruskal Wallis test (Non-Parametric ANOVA) with the Dunnett post test was used for statistical analysis. RESULTS: The indirect ELISA method yielded 84% sensitivity and 90% specificity for the diagnosis of TBM using mAb to 65 kD hsp antigen. The mean absorbance value of 65 kD hsp antigen in TBM patients was [0.70 ± 0.23 (0.23–1.29)], significantly higher than the non-TBM infectious meningitis group [0.32 ± 0.14 (0.12–0.78), P < 0.001] and also higher than the non-infectious neurological disorders group [0.32 ± 0.13 (0.20–0.78), P < 0.001]. A significant difference in the mean absorbance of 65 kD hsp antigen was noted in the CSF of culture-positive TBM patients [0.94 ± 0.18 (0.54–1.29)] when compared with clinically suspected TBM patients [0.64 ± 0.20 (0.23–0.98), P < 0.05]. CONCLUSION: The presence of 65 kD hsp antigen in the CSF of confirmed and suspected cases of TBM would indicate that the selected protein is specific to M. tuberculosis and could be considered as a diagnostic marker for TBM
Improving Power Delivery of Grid-Connected Induction Machine Based Wind Generators under Dynamic Conditions Using Feedforward Linear Neural Networks
In the conventional grid-connected Wind Energy Conversion System (WECS), the generator side inverter is typically controlled via Field Oriented Control (FOC), while Voltage Oriented Control (VOC) controls the grid side inverter. However, robust operation cannot be guaranteed during sudden changes in wind speeds and weak grid connections. This paper presents a novel method to improve the overall dynamic performance of on-grid induction machine-based wind generators. An online mechanical parameter estimation technique is devised using Recursive Least Squares (RLS) to compute the machine inertia and friction coefficient iteratively. An adaptive feedforward neural (AFN) controller is also proposed in the synchronous reference frame, which is constructed using the estimated parameters and the system's inverse. The output of the neural controller is added to the output of the speed PI controller in the outer loop of the FOC to enhance the speed response of the wind generator. A similar approach is taken to improve the classical VOC structure for the grid-side inverter. In this case, the RLS estimates the equivalent Thevenin's grid impedance in real-time. As for the adaptive action, two identical neural networks are integrated with the inner loop direct and quadrature axis current PI controllers. Under nominal operating conditions, it is observed that the PI+AFN provides a faster settling time for the generator's speed and torque response. Upon being subjected to variations in the wind speed, the PI+AFN outperforms the classical PI controller and attains a lower integral-time error. In addition, the proposed PI+AFN controller has a better ability to maintain the grid-side inverter stability during stochastic variations in grid impedance. One significant advantage of the proposed control approach is that no data for training or validation is required since the neural network weights are directly the output of the RLS estimator. Hardware verification for the improved FOC for wind generators using the adaptive controller is also made using the DSPACE 1007 AUTOBOX platform
Promising Practices From Fiji in Empowering Women Economically: Learnings From Talanoa Treks, Ra Naari Parishad, Rise Beyond the Reef, and the Fiji Womens Fund
This paper is jointly authored by eight women who work with the Fiji Women's Fund and three of the Fund's partner organisations - Talanoa Treks, Ra Naari Parishad, and, Rise Beyond the Reef. The paper aims to contribute to improved women's economic empowerment programs by sharing the experiences of these three partners. The authors document the learnings of practitioners in Fiji and compare these with the existing literature for the audience of practitioners in the Pacific and abroad. The Fiji Women's Fund supports the documentation of research from practice, so that the expertise of practitioners is recognised, and, to increase the body of knowledge generated from the Global South.The paper examines the experiences and learnings of the three partners using the Gender at Work framework, developed by Rao and Kelleher, which highlights the inter-linked dimensions of change required to achieve sustainable progress on gender equality and women's empowerment. The paper documents the similar journey taken by all three partner organisations, through each of the four quadrants of this framework. All three entities supported the establishment of a formal, collective structure being established, to provide women access to training and income-generating opportunities. Women accessed these opportunities to improve their skills, capabilities, income and assets. These changes, in turn, had an influence on the way the women themselves, and the men in their lives, think about what it means to be a woman or a man and the possibilities available. For example, there is evidence of positive changes to what women and men are doing in their households. Husbands, sons and partners are helping women beneficiaries by taking on some of the care tasks that were previously left to the women. The greatest evidence of change is within households, as changes to exclusionary practices at the village level are less evident
Cerebrospinal fluid adenosine deaminase activity: A complimentary tool in the early diagnosis of tuberculous meningitis
BACKGROUND: Tuberculous meningitis (TBM) is the commonest form of neurotuberculosis caused by Mycobacterium tuberculosis bacilli (MTB). The diagnosis of TBM is often difficult. A reliable, cost-effective and rapid diagnostic test, which can be performed in any standard pathology laboratory, could be of help in the diagnosis of TBM. In the present study we measured the adenosine deaminase (ADA) activity in cerebrospinal fluid (CSF) of TBM and non-TBM patients. METHOD: ADA activity in CSF was determined according to a method based on the Berthlot reaction, which is the formation of a colored indophenol complex from ammonia liberated from adenosine, and quantified spectrophotometrically. RESULTS: The CSF ADA activity from TBM patients was compared with CSF ADA from non-TBM infectious meningitis patients, and from patients with non-infectious neurological disorders. The mean CSF ADA activity was found to be significantly higher in CSF of TBM patients, 14.31 ± 3.87 (2.99–26.94), mean ± SD with range, than in the CSF from non-TBM infectious meningitis, 9.25 ± 2.14 (4.99–13.96) and from the non-infectious neurological disorders group, 2.71 ± 1.96 (0.00–7.68), P < 0.0001 for both comparisons. A cut-off value of 11.39 U/L/min for the TBM patients was calculated from the mean + SD of the non-TBM patients. The ADA test gave a sensitivity of 82% and a specificity of 83% for infectious TBM when this cut-off value was used. CONCLUSION: This study demonstrated that ADA activity in the CSF of TBM patients, using a cut-off value 11.39 U/L/min, can be useful for the early differential diagnosis of TBM. This test can be performed in any pathology laboratory where more sophisticated methods are not available
(2E,6E)-2,6-Bis(2,4,5-trimethoxyÂbenzylÂidene)cycloÂhexaÂnone
In the title compound, C26H30O7, one atom in the cycloÂhexaÂnone ring is disordered over two positions with a site-occupancy ratio of 0.871 (6):0.129 (6). The dihedral angles formed between the mean plane through the six C atoms of the major component of the cycloÂhexaÂnone ring and two benzene rings are 35.09 (10) and 34.21 (10)°; the corresponding angles for the minor component are 20.1 (2) and 19.5 (2)°. Both the major and minor disordered components of the cycloÂhexaÂnone ring adopt half-boat conformations. In the crystal packing, interÂmolecular C—H⋯O hydrogen bonds connect the molÂecules into a three-dimensional network
Tumor-Derived Exosome and Immune Modulation
Tumor cells, like most other cells, release exosomes called tumor-derived exosomes (TEX) and are vital for intercellular communication. TEX are membrane-bound extracellular vesicles (EVs), containing unique cargo reminiscent of the parent tumor cells and possess immunomodulatory functions. TEX carries factors that directly promote immunosuppression in the tumor microenvironment and indirectly attract immunosuppressive T-regulatory (Treg) cells. The tumor-secreted exosomes can transfer their cargo by multiple mechanisms like fusion, phagocytosis, and receptor-mediated endocytosis, activating the recipient cells. TEX directly engages and releases cytokines, inactivating natural killer (NK) cells and T-cells and activating apoptosis. Tumor-derived exosomes also release soluble factors to suppress dendritic cell (DC) maturation while activating the expansion of immune-suppressive cells like Myeloid-derived suppressor cells (MDSCs) and Regulatory T (Treg) cells. Several studies have shown the relevance of TEX containing tumor-associated antigens (TAA) in reducing the efficacy of cancer immunotherapy and adoptive cell therapy. Hence understanding the basic biology and mechanism of TEX-mediated immunosuppression is critical in discovering cancer biomarkers and finding better immunotherapy and cell therapy approaches. In this chapter, we have discussed TEX biogenesis, TEX\u27s structural and molecular features, TEX-mediated immunosuppression, and its relation to immunotherapy
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