70 research outputs found

    A Novel Role for the NLRC4 Inflammasome in Mucosal Defenses against the Fungal Pathogen Candida albicans

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    Candida sp. are opportunistic fungal pathogens that colonize the skin and oral cavity and, when overgrown under permissive conditions, cause inflammation and disease. Previously, we identified a central role for the NLRP3 inflammasome in regulating IL-1β production and resistance to dissemination from oral infection with Candida albicans. Here we show that mucosal expression of NLRP3 and NLRC4 is induced by Candida infection, and up-regulation of these molecules is impaired in NLRP3 and NLRC4 deficient mice. Additionally, we reveal a role for the NLRC4 inflammasome in anti-fungal defenses. NLRC4 is important for control of mucosal Candida infection and impacts inflammatory cell recruitment to infected tissues, as well as protects against systemic dissemination of infection. Deficiency in either NLRC4 or NLRP3 results in severely attenuated pro-inflammatory and antimicrobial peptide responses in the oral cavity. Using bone marrow chimeric mouse models, we show that, in contrast to NLRP3 which limits the severity of infection when present in either the hematopoietic or stromal compartments, NLRC4 plays an important role in limiting mucosal candidiasis when functioning at the level of the mucosal stroma. Collectively, these studies reveal the tissue specific roles of the NLRP3 and NLRC4 inflammasome in innate immune responses against mucosal Candida infection

    Spectral Modelling on the Characteristics of High Frequency Tail in Shallow Water Wave Spectra at Coastal Puducherry, East Coast of India

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    About 8 years of measured wave spectra (June 2007–December 2014) off coastal Puducherry located in the east coast of India and bordering the Bay of Bengal were analyzed with an objective to understand the slope of the high frequency tail of the wave spectrum and to determine the occurrence of single peaked, double-peaked and multi-peaked spectra in varying sea states. The temporal and inter-annual variation of the spectral energy density over the years indicates marked variability and the study signifies that wave spectra were multi-peaked from June to October and predominantly double peaked during the rest of the year. Swell and wind sea components have been estimated from the wave spectra by separation frequency method. The analysis shows that swells dominate Puducherry coastal region not only during southwest monsoon (95%), but also during the post-monsoon (100%) and northeast monsoon season. The measured wave spectra were compared with numerical wave model outputs to attain a level of confidence with the buoy data. In addition, analysis on the slope of the high frequency tail of the wave energy spectra shows that its slope varied seasonally in the range of − 1.96 to − 3.27 at the coastal location. Further, the JONSWAP model fitted into measured wave spectra showed high discrepancy between the two, especially in the high frequency tail with Scatter Index ranging between 0.79 and 3.98. The correct slope for the high frequency or even whether a unique slope exists remains elusive for the ocean wave communit

    Carbamazepine - The commonest cause of toxic epidermal necrolysis and Stevens-Johnson syndrome: A study of 7 years

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    Background : Toxic epidermal necrolysis (TEN) and Stevens-Johnson syndrome (SJS) are a group of severe life threatening drug reactions. The drugs commonly implicated as the cause of these drug reactions vary depending on host factors and the prescription pattern of drugs in that particular area. Aim : The aim of the study was to find the drugs implicated as the cause of SJS/TEN in the patients admitted in the dermatology ward at the Medical College, Thrissur and to find the clinical outcome. Methods : It was a retrospective study of 7 years from 1997 to 2004. The case records of all patients with a clinical diagnosis of TEN or SJS were studied in detail regarding the drugs implicated as the cause, the management and the clinical outcome. Results : During the study period, 41 patients in the age group ranging from 12 to 72 years were treated as inpatients, of which 20 were males and 21 were females. The commonest drug implicated as the cause of SJS/TEN was carbamazepine (44%). The indication for carbamazepine was control of pain in more than 50% of the cases. Presence of a major systemic disease before the onset of SJS/TEN was associated with a bad prognosis. Conclusion : The increased use of carbamazepine, especially for control of pain, may be the reason for the increased incidence of SJS/TEN due to the same drug. Awareness about the drugs implicated in life threatening drug reactions will help physicians in preventing them by judicious use of the drugs

    Neural-Network-Based Data Assimilation to Improve Numerical Ocean Wave Forecast

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    This paper demonstrates the skill level of a wavelet neural network in improving numerical ocean wave predictions of significant wave height (H-s) and peak wave period (T-p) having practical applications in operational centers. The study uses data of H-s and T-p for a coastal region off Puducherry located in the east coast of India, and obtained from a high-resolution wave model resulting from nesting of the SWAN model with the WW3 model. A wave rider buoy located off Puducherry provided data for a period of 25 months during the period from June 2007 until July 2009 used in this study. The time series of error between numerical and corresponding measured values was first constructed, and using a wavelet neural network, the errors were predicted for future time steps. The predicted errors when incorporated into the model values provided the updated prediction of H-s and T-p. The study signifies that numerical estimations could be significantly improved using this procedure. The results provide quite satisfactory predictions with a lead time varying from 3 to 24 h. The study points out that adequate training of the neural network is an essential prerequisite to obtain good performance and skill levels. A comparison between the suggested prediction method with the standalone neural network model trained with measured data off Puducherry showed that the former approach is preferred over the latter in obtaining a sustained prediction performance

    Wave forecasting system for operational use and its validation at coastal Puducherry, east coast of India

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    An incredible demand for coastal sea-state forecast in recent years has led to development and implementation of wave forecasting system in operational centers, having wide practical applications relevant to marine industry. The wave forecasting system takes advantage of parametric techniques, by nesting global ocean wave models to coastal and near-shore high-resolution wave models. The Indian National Centre for Ocean Information Services (INCOIS) at Hyderabad has a mandate for operational marine weather forecast services that envisages integration and coupling state-of-the-art weather models for operational oceanographic needs. In the present study, two state-of-art wave models viz; WAVEWATCH III (WW3) and Simulating WAves Nearshore (SWAN) are nested and forced with French Research Institute for Exploitation of the Sea/Laboratory of Oceanography From Space (IFREMER/CERSAT) blended surface winds. The objective is to investigate wave evolution at a coastal location off Puducherry in the east coast of India. To evaluate model performance, a detailed validation study is performed by comparing model-simulated wave parameters and wave spectra with corresponding in-situ wave rider buoy observations for four prominent seasons viz; northeast monsoon, southwest monsoon, pre- and post-monsoon. The study signifies applicability of nested wave model for operational use during normal weather condition at coastal Puducherry

    Reliability of single and dual layer Pt Nanocrystal devices for NAND flash applications : a 2-region model for endurance defect generation

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    Nanocrystal (NC) based memory devices are considered a possible alternative for floating gate (FG) replacement below 30nm node. In this work, endurance reliability of Pt NC devices is investigated for single layer (SL) and dual layer (DL) structures. The degradation in the devices due to Program/Erase (P/E) stress is investigated. Relative improvement in reliability of DL structure over SL structure is shown. A physical model for defect generation in the gate stack is proposed which is able to explain endurance and post-cycling characteristics. Dual layer structure is shown to have better inherent reliability over single layer structure

    Recent advances in charge trap flash memories

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    This paper reviews recent advances in Charge Trap Flash (CTF) memories. CTFs are predicted to replace the traditional floating-gate flash devices beyond the 32 nm node. The paper focuses on work done at IIT Bombay in the areas of both nitride-based SONOS devices as well as nanocrystal (NC)-based devices. For SONOS devices, results are presented for optimization of the nitride layer to obtain the best characteristics, and the simulation of the program/erase transients. For NC devices, experimental characteristics of single and dual layer cells, as well as simulation results are presented
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