208 research outputs found
A nonlinear M-estimation approach to robust asynchronous multiuser detection in Non-gaussian noise
A nonlinear M-estimation approach is proposed to solve the multiuser detection problem in asynchronous code-division multiple-access (CDMA) systems where the ambient noise is impulsive and the delays are not known. We treat the unknown delays as nuisance parameters and the transmitted symbols as parameters of interest. We also analyze the asymptotic performance of the proposed estimator and propose suboptimal but computationally efficient procedures for solving the nonlinear optimization function. Simulation results show considerable improvements over the conventional approaches
An optimisation approach to robust estimation of mulitcomponent polynomial phase signals in non-Gaussian noise
In this paper, we address the problem of estimating the parameters of multicomponent polynomial phase signals in impulsive noise which arises in many practical situations. In the presence of this non-standard noise, existing techniques perform can poorly. We propose a nonlinear M-estimation approach to improve the existing techniques. The phase parameters are obtained by solving a nonlinear optimisation problem. A procedure is proposed to find the global minimum at low computational cost. Simulation examples show the proposed method performs better than existing method
Morbidity after surgical management of cervical cancer in low and middle income countries: A systematic review and meta-analysis
Objective: To investigate morbidity for patients after the primary surgical management of cervical cancer in low and middle-income countries (LMIC).
Methods: The Pubmed, Cochrane, the Cochrane Central Register of Controlled Trials, Embase, LILACS and CINAHL were searched for published studies from 1st Jan 2000 to 30th June 2017 reporting outcomes of surgical management of cervical cancer in LMIC. Randomeffects meta-analytical models were used to calculate pooled estimates of surgical complications including blood transfusions, ureteric, bladder, bowel, vascular and nerve injury, fistulae and thromboembolic events. Secondary outcomes included five-year progression free (PFS) and overall survival (OS).
Findings: Data were available for 46 studies, including 10,847 patients from 11 middle income countries. Pooled estimates were: blood transfusion 29% (95%CI 0.19–0.41, P = 0.00, I 2 = 97.81), nerve injury 1% (95%CI 0.00–0.03, I 2 77.80, P = 0.00), bowel injury, 0.5% (95%CI 0.01–0.01, I 2 = 0.00, P = 0.77), bladder injury 1% (95%CI 0.01–0.02, P = 0.10, I 2 = 32.2), ureteric injury 1% (95%CI 0.01–0.01, I 2 0.00, P = 0.64), vascular injury 2% (95% CI 0.01– 0.03, I 2 60.22, P = 0.00), fistula 2% (95%CI 0.01–0.03, I 2 = 77.32, P = 0.00,), pulmonary embolism 0.4% (95%CI 0.00–0.01, I 2 26.69, P = 0.25), and infection 8% (95%CI 0.04–0.12, 2 95.72, P = 0.00). 5-year PFS was 83% for laparotomy, 84% for laparoscopy and OS was 85% for laparotomy cases and 80% for laparoscopy.
Conclusion: This is the first systematic review and meta-analysis of surgical morbidity in cervical cancer in LMIC, which highlights the limitations of the current data and provides a benchmark for future health services research and policy implementation
Roles of Tumor Suppressor Signaling on Reprogramming and Stemness Transition in Somatic Cells
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Single-trial event-related potential extraction through one-unit ICA-with-reference.
Objective: In recent years, ICA has been one of the more popular methods for extracting event-related potential (ERP) at the single-trial level. It is a blind source separation technique that allows the extraction of an ERP without making strong assumptions on the temporal and spatial characteristics of an ERP. However, the problem with traditional ICA is that the extraction is not direct and is time-consuming due to the need for source selection processing. In this paper, the application of an one-unit ICA-with-Reference (ICA-R), a constrained ICA method, is proposed. Approach: In cases where the time-region of the desired ERP is known a priori, this time information is utilized to generate a reference signal, which is then used for guiding the one-unit ICA-R to extract the source signal of the desired ERP directly. Main results: Our results showed that, as compared to traditional ICA, ICA-R is a more effective method for analysing ERP because it avoids manual source selection and it requires less computation thus resulting in faster ERP extraction. Significance: In addition to that, since the method is automated, it reduces the risks of any subjective bias in the ERP analysis. It is also a potential tool for extracting the ERP in online application
Transformations for non-ideal uniform circular arrays operating in correlated signal environments
The Davies transformation is a method to transform the steering vector of a uniform circular array (UCA) to one with Vandermonde form. As such, it allows techniques such as spatial smoothing for direction-of-arrival (DOA) estimation in a correlated signal environment, developed originally for uniform linear arrays, to be applied to UCAs. However, the Davies transformation can be highly sensitive to perturbations of the underlying array model. This paper presents a method for deriving a more robust transformation using optimization techniques. The effectiveness of the method is illustrated through a number of DOA estimation examples
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Repurposing hyperpolarization-activated cyclic nucleotide-gated channels as a novel therapy for breast cancer.
Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are members of the voltage-gated cation channel family known to be expressed in the heart and central nervous system. Ivabradine, a small molecule HCN channel-blocker, is FDA-approved for clinical use as a heart rate-reducing agent. We found that HCN2 and HCN3 are overexpressed in breast cancer cells compared with normal breast epithelia, and the high expression of HCN2 and HCN3 is associated with poorer survival in breast cancer patients. Inhibition of HCN by Ivabradine or by RNAi, aborted breast cancer cell proliferation in vitro and suppressed tumour growth in patient-derived tumour xenograft models established from triple-negative breast cancer (TNBC) tissues, with no evident side-effects on the mice. Transcriptome-wide analysis showed enrichment for cholesterol metabolism and biosynthesis as well as lipid metabolism pathways associated with ER-stress following Ivabradine treatment. Mechanistic studies confirmed that HCN inhibition leads to ER-stress, in part due to disturbed Ca2+ homeostasis, which subsequently triggered the apoptosis cascade. More importantly, we investigated the synergistic effect of Ivabradine and paclitaxel on TNBC and confirmed that both drugs acted synergistically in vitro through ER-stress to amplify signals for caspase activation. Combination therapy could suppress tumour growth of xenografts at much lower doses for both drugs. In summary, our study identified a new molecular target with potential for being developed into targeted therapy, providing scientific grounds for initiating clinical trials for a new treatment regimen of combining HCN inhibition with chemotherapy
Dietary compound Isoliquiritigenin prevents mammary carcinogenesis by inhibiting breast cancer stem cells through WIF1 demethylation
Breast cancer stem cells (CSCs) are considered as the root of mammary tumorigenesis. Previous studies have demonstrated that ISL efficiently limited the activities of breast CSCs. However, the cancer prevention activities of ISL and its precise molecular mechanisms remain largely unknown. Here, we report a novel function of ISL as a natural demethylation agent targeting WIF1 to prevent breast cancer. ISL administration suppressed in vivo breast cancer initiation and progression, accompanied by reduced CSC-like populations. A global gene expression profile assay further identified WIF1 as the main response gene of ISL treatment, accompanied by the simultaneous downregulation of β-catenin signaling and G0/G1 phase arrest in breast CSCs. In addition, WIF1 inhibition significantly relieved the CSC-limiting effects of ISL and methylation analysis further revealed that ISL enhanced WIF1 gene expression via promoting the demethylation of its promoter, which was closely correlated with the inhibition of DNMT1 methyltransferase. Molecular docking analysis finally revealed that ISL could stably dock into the catalytic domain of DNMT1. Taken together, our findings not only provide preclinical evidence to demonstrate the use of ISL as a dietary supplement to inhibit mammary carcinogenesis but also shed novel light on WIF1 as an epigenetic target for breast cancer prevention.published_or_final_versio
Genetic Associations of Type 2 Diabetes with Islet Amyloid Polypeptide Processing and Degrading Pathways in Asian Populations
10.1371/journal.pone.0062378PLoS ONE86
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