Net Influence of an Internally Generated Guasi-biennial Oscillation on Modelled Stratospheric Climate and Chemistry

A Goddard Earth Observing System Chemistry- Climate Model (GEOSCCM) simulation with strong tropical non-orographic gravity wave drag (GWD) is compared to an otherwise identical simulation with near-zero tropical non-orographic GWD. The GEOSCCM generates a quasibiennial oscillation (QBO) zonal wind signal in response to a tropical peak in GWD that resembles the zonal and climatological mean precipitation field. The modelled QBO has a frequency and amplitude that closely resembles observations. As expected, the modelled QBO improves the simulation of tropical zonal winds and enhances tropical and subtropical stratospheric variability. Also, inclusion of the QBO slows the meridional overturning circulation, resulting in a generally older stratospheric mean age of air. Slowing of the overturning circulation, changes in stratospheric temperature and enhanced subtropical mixing all affect the annual mean distributions of ozone, methane and nitrous oxide. Furthermore, the modelled QBO enhances polar stratospheric variability in winter. Because tropical zonal winds are easterly in the simulation without a QBO, there is a relative increase in tropical zonal winds in the simulation with a QBO. Extratropical differences between the simulations with and without a QBO thus reflect the westerly shift in tropical zonal winds: a relative strengthening of the polar stratospheric jet, polar stratospheric cooling and a weak reduction in Arctic lower stratospheric ozone

Peutz-Jeghers Syndrome with Multiple Genital Tract Tumors and Breast Cancer: A Case Report with a Review of Literatures

We report here on the multiple genital tract neoplasms in a 41-yr-old Korean woman with Peutz-Jeghers Syndrome (PJS). The patient presented with lower abdominal pain. Her previous medical history was PJS and breast cancer. Pelvic ultrasound showed a multilocular cyst at the right adnexal region, diagnosed as bilateral ovarian mucinous borderline tumors. An ovarian sex cord tumor with annular tubules was incidentally diagnosed together with a minimal deviation adenocarcinoma of the uterine cervix and mucinous metaplasia of both the Fallopian tubal mucosa and the endometrium. Although the cases of multiple genital tract tumors with PJS has rarely been reported, the present case appears to be the first in Korea in which the PJS syndrome was complicated by multiple genital tract tumors and infiltrating carcinoma of the breast. The clinical significance of the multiple genital tract tumors and breast cancer associated with PJS is reviewed

Release of mineral-bound water prior to subduction tied to shallow seismogenic slip off Sumatra

Plate-boundary fault rupture during the 2004 Sumatra-Andaman subduction earthquake extended closer to the trench than expected, increasing earthquake and tsunami size. International Ocean Discovery Program Expedition 362 sampled incoming sediments offshore northern Sumatra, revealing recent release of fresh water within the deep sediments. Thermal modeling links this freshening to amorphous silica dehydration driven by rapid burial-induced temperature increases in the past 9 million years. Complete dehydration of silicates is expected before plate subduction, contrasting with prevailing models for subduction seismogenesis calling for fluid production during subduction. Shallow slip offshore Sumatra appears driven by diagenetic strengthening of deeply buried fault-forming sediments, contrasting with weakening proposed for the shallow Tohoku-Oki 2011 rupture, but our results are applicable to other thickly sedimented subduction zones including those with limited earthquake records

A variable step-size affine projection algorithm with a step-size scaler against impulsive measurement noise

This letter proposes a variable step-size (VSS) affine projection algorithm (APA) associated with a step-size scaler to improve the APA's robustness against impulsive measurement noise. In the proposed VSS APA, the step-size scaler is applied to the equations for updating the step size, which are developed by interpreting the behavior of the mean square deviation (MSD) of the conventional APA. To reduce the computational complexity, we also propose a simplified version of the step-size scaler, which is suitable for application in the APA. Simulations show that the proposed algorithm leads to an excellent transient and steady-state behavior with colored inputs in impulsive-noise environments. (C) 2013 Elsevier B.V. All rights reserved.X116sciescopu

A variable step-size normalized subband adaptive filter with a step-size scaler against impulsive measurement noise

This brief introduces a variable step-size (VSS) normalized subband adaptive filter (NSAF) using a step-size scaler to improve the robustness against impulsive measurement noise. When impulsive measurement noise appears, the step size of the proposed VSS NSAF is scaled down by the step-size scaler, which is suitable for application in the NSAF. This removes a possibility of updating weight estimates based on defective information of the subband output errors due to impulsive measurement noise. In the proposed VSS NSAF, the equations for updating the step size are constructed by interpreting the behavior of the mean square deviation of the conventional NSAF and applying the step-size scaler. The step-size scaler utilizes the sum of the subband output errors, which can be influenced by impulsive measurement noise. Simulations using the proposed VSS NSAF show an excellent transient and steady-state behavior with colored input in impulsive-noise environments.116Nsciescopu

A Normalized Least Mean Squares Algorithm With a Step-Size Scaler Against Impulsive Measurement Noise

This brief introduces the concept of a step-size scaler by investigating and modifying the tanh cost function for adaptive filtering with impulsive measurement noise. The step-size scaler instantly scales down the step size of gradient-based adaptive algorithms whenever impulsive measurement noise appears, which eliminates a possibility of updating weight vector estimates based on wrong information due to impulsive noise. The most attractive feature of the step-size scaler is that this is easily applicable to various gradient-based adaptive algorithms. Several representative gradient-based adaptive algorithms are performed without or with the step-size scaler in impulsive-noise environments, which shows the improvement of robustness against impulsive noise.X112220sciescopu

Glycogen Synthase Kinase 3 Inactivation Induces Cell Senescence through Sterol Regulatory Element Binding Protein 1-Mediated Lipogenesis in Chang Cells

BackgroundEnhanced lipogenesis plays a critical role in cell senescence via induction of expression of the mature form of sterol regulatory element binding protein 1 (SREBP1), which contributes to an increase in organellar mass, one of the indicators of senescence. We investigated the molecular mechanisms by which signaling molecules control SREBP1-mediated lipogenesis and senescence.MethodsWe developed cellular models for stress-induced senescence, by exposing Chang cells, which are immortalized human liver cells, to subcytotoxic concentrations (200 µM) of deferoxamine (DFO) and H2O2.ResultsIn this model of stress-induced cell senescence using DFO and H2O2, the phosphorylation profile of glycogen synthase kinase 3α (GSK3α) and β corresponded closely to the expression profile of the mature form of SREBP-1 protein. Inhibition of GSK3 with a subcytotoxic concentration of the selective GSK3 inhibitor SB415286 significantly increased mature SREBP1 expression, as well as lipogenesis and organellar mass. In addition, GSK3 inhibition was sufficient to induce senescence in Chang cells. Suppression of GSK3 expression with siRNAs specific to GSK3α and β also increased mature SREBP1 expression and induced senescence. Finally, blocking lipogenesis with fatty acid synthase inhibitors (cerulenin and C75) and siRNA-mediated silencing of SREBP1 and ATP citrate lyase (ACL) significantly attenuated GSK3 inhibition-induced senescence.ConclusionGSK3 inactivation is an important upstream event that induces SREBP1-mediated lipogenesis and consequent cell senescence

Therapeutic Potential of Human Fetal Mesenchymal Stem Cells in Musculoskeletal Disorders: A Narrative Review

Mesenchymal stem cells (MSCs) have emerged as a promising therapeutic approach for diverse diseases and injuries. The biological and clinical advantages of human fetal MSCs (hfMSCs) have recently been reported. In terms of promising therapeutic approaches for diverse diseases and injuries, hfMSCs have gained prominence as healing tools for clinical therapies. Therefore, this review assesses not the only biological advantages of hfMSCs for healing human diseases and regeneration, but also the research evidence for the engraftment and immunomodulation of hfMSCs based on their sources and biological components. Of particular clinical relevance, the present review also suggests the potential therapeutic feasibilities of hfMSCs for musculoskeletal disorders, including osteoporosis, osteoarthritis, and osteogenesis imperfecta