72 research outputs found

    Triple leads with longitudinal guarded cathodes in spinal cord stimulation-effect of transversal lead separation

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    In spinal cord stimulation (SCS) clinical practice, longitudinal guarded cathode stimulation by a single lead, placed on the spinal cord midline provides the broadest parasthesia coverage. This study uses a triple lead longitudinal tripole with the center lead placed on the midline. The transversal spacing between the leads is varied to study its effect on the usage range (UR) and the recruited area (both depth and width) of dorsal colums activation

    Resources of Ribbon Fish and Cat Fish off the South West Coast of lndia

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    The acoustic surveys and fishing experiments conducted by the research vessels RASTRELLIGER and SARDINELLA of the Pelagic Fishery Project from Ratnagiri to the Gulf of Mannar for the past four years have considerably enhanced our knowledge of the pelagic fishery resources, their abundance and seasonal distribution and possible methods of exploitation (Anonymous 1974, 1975 & 1976). The average annual landings of ribbon fish and cat fish for the past ten years with 78,000tonnes form only 7.7% of the total marine fish production in India

    High Resolution Observations using Adaptive Optics: Achievements and Future Needs

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    Over the last few years, several interesting observations were obtained with the help of solar Adaptive Optics (AO). In this paper, few observations made using the solar AO are enlightened and briefly discussed. A list of disadvantages with the current AO system are presented. With telescopes larger than 1.5m are expected during the next decade, there is a need to develop the existing AO technologies for large aperture telescopes. Some aspects of this development are highlighted. Finally, the recent AO developments in India are also presented

    Characterization of horizontal flows around solar pores from high-resolution time series of images

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    Though there is increasing evidence linking the moat flow and the Evershed flow along the penumbral filaments, there is not a clear consensus regarding the existence of a moat flow around umbral cores and pores, and the debate is still open. Solar pores appear to be a suitable scenario to test the moat-penumbra relation as evidencing the direct interaction between the umbra and the convective plasma in the surrounding photosphere, without any intermediate structure in between. The present work studies solar pores based on high resolution ground-based and satellite observations. Local correlation tracking techniques have been applied to different-duration time series to analyze the horizontal flows around several solar pores. Our results establish that the flows calculated from different solar pore observations are coherent among each other and show the determinant and overall influence of exploding events in the granulation around the pores. We do not find any sign of moat-like flows surrounding solar pores but a clearly defined region of inflows surrounding them. The connection between moat flows and flows associated to penumbral filaments is hereby reinforced by this work.Comment: 10 pages, 10 figures, Accepted for publication in Astronomy and Astrophysics

    Identification of YWHAH as a Novel Brain-Derived Extracellular Vesicle Marker Post Long-Term Midazolam Exposure during Early Development

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    Recently, the long-term use of sedative agents in the neonatal intensive care unit (NICU) has raised concerns about neurodevelopmental outcomes in exposed neonates. Midazolam (MDZ), a common neonatal sedative in the NICU, has been suggested to increase learning disturbances and cognitive impairment in children. However, molecular mechanisms contributing to such outcomes with long-term MDZ use during the early stages of life remain unclear. In this study, we for the first time elucidate the role of brain-derived extracellular vesicles (BDEVs), including mining the BDEV proteome post long-term MDZ exposure during early development. Employing our previously established rodent model system that mimics the exposure of MDZ in the NICU using an increasing dosage regimen, we isolated BDEVs from postnatal 21-days-old control and MDZ groups using a differential sucrose density gradient. BDEVs from the control and MDZ groups were then characterized using a ZetaView nanoparticle tracking analyzer and transmission electron microscopy analysis. Next, using RT-qPCR, we examined the expression of key ESCRT-related genes involved in EV biogenesis. Lastly, using quantitative mass spectrometry-based proteomics, we mined the BDEV protein cargo that revealed key differentially expressed proteins and associated molecular pathways to be altered post long-term MDZ exposure. Our study characterized the proteome in BDEV cargo from long-term MDZ exposure at early development. Importantly, we identified and validated the expression of YWHAH as a potential target for further characterization of its downstream mechanism and a potential biomarker for the early onset of neurodevelopment and neurodegenerative diseases. Overall, the present study demonstrated long-term exposure to MDZ at early development stages could influence BDEV protein cargo, which potentially impact neural functions and behavior at later stages of development

    In-orbit Performance of UVIT on ASTROSAT

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    We present the in-orbit performance and the first results from the ultra-violet Imaging telescope (UVIT) on ASTROSAT. UVIT consists of two identical 38cm coaligned telescopes, one for the FUV channel (130-180nm) and the other for the NUV (200-300nm) and VIS (320-550nm) channels, with a field of view of 28 arcminarcmin. The FUV and the NUV detectors are operated in the high gain photon counting mode whereas the VIS detector is operated in the low gain integration mode. The FUV and NUV channels have filters and gratings, whereas the VIS channel has filters. The ASTROSAT was launched on 28th September 2015. The performance verification of UVIT was carried out after the opening of the UVIT doors on 30th November 2015, till the end of March 2016 within the allotted time of 50 days for calibration. All the on-board systems were found to be working satisfactorily. During the PV phase, the UVIT observed several calibration sources to characterise the instrument and a few objects to demonstrate the capability of the UVIT. The resolution of the UVIT was found to be about 1.4 - 1.7 arcsecarcsec in the FUV and NUV. The sensitivity in various filters were calibrated using standard stars (white dwarfs), to estimate the zero-point magnitudes as well as the flux conversion factor. The gratings were also calibrated to estimate their resolution as well as effective area. The sensitivity of the filters were found to be reduced up to 15\% with respect to the ground calibrations. The sensitivity variation is monitored on a monthly basis. UVIT is all set to roll out science results with its imaging capability with good resolution and large field of view, capability to sample the UV spectral region using different filters and capability to perform variability studies in the UV.Comment: 10 pages, To appear in SPIE conference proceedings, SPIE conference paper, 201

    Two-Dimensional Spectroscopy of Photospheric Shear Flows in a Small delta Spot

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    In recent high-resolution observations of complex active regions, long-lasting and well-defined regions of strong flows were identified in major flares and associated with bright kernels of visible, near-infrared, and X-ray radiation. These flows, which occurred in the proximity of the magnetic neutral line, significantly contributed to the generation of magnetic shear. Signatures of these shear flows are strongly curved penumbral filaments, which are almost tangential to sunspot umbrae rather than exhibiting the typical radial filamentary structure. Solar active region NOAA 10756 was a moderately complex, beta-delta sunspot group, which provided an opportunity to extend previous studies of such shear flows to quieter settings. We conclude that shear flows are a common phenomenon in complex active regions and delta spots. However, they are not necessarily a prerequisite condition for flaring. Indeed, in the present observations, the photospheric shear flows along the magnetic neutral line are not related to any change of the local magnetic shear. We present high-resolution observations of NOAA 10756 obtained with the 65-cm vacuum reflector at Big Bear Solar Observatory (BBSO). Time series of speckle-reconstructed white-light images and two-dimensional spectroscopic data were combined to study the temporal evolution of the three-dimensional vector flow field in the beta-delta sunspot group. An hour-long data set of consistent high quality was obtained, which had a cadence of better than 30 seconds and sub-arcsecond spatial resolution.Comment: 23 pages, 6 gray-scale figures, 4 color figures, 2 tables, submitted to Solar Physic

    A Holistic Systems Approach to Characterize the Impact of Pre- and Post-natal Oxycodone Exposure on Neurodevelopment and Behavior

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    Background: Increased risk of oxycodone (oxy) dependency during pregnancy has been associated with altered behaviors and cognitive deficits in exposed offspring. However, a significant knowledge gap remains regarding the effect of in utero and postnatal exposure on neurodevelopment and subsequent behavioral outcomes. Methods: Using a preclinical rodent model that mimics oxy exposure in utero (IUO) and postnatally (PNO), we employed an integrative holistic systems biology approach encompassing proton magnetic resonance spectroscopy (1H-MRS), electrophysiology, RNA-sequencing, and Von Frey pain testing to elucidate molecular and behavioral changes in the exposed offspring during early neurodevelopment as well as adulthood. Results: 1H-MRS studies revealed significant changes in key brain metabolites in the exposed offspring that were corroborated with changes in synaptic currents. Transcriptomic analysis employing RNA-sequencing identified alterations in the expression of pivotal genes associated with synaptic transmission, neurodevelopment, mood disorders, and addiction in the treatment groups. Furthermore, Von Frey analysis revealed lower pain thresholds in both exposed groups. Conclusions: Given the increased use of opiates, understanding the persistent developmental effects of these drugs on children will delineate potential risks associated with opiate use beyond the direct effects in pregnant women

    Microstructural and Compositional Characterisation of Electronic Materials

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    Microstructural and compositional characterisation of electronic materials in support of the development of GaAs, GaN and GaSb based multilayer device structures is described. Electron microscopy techniques employing nanometer and sub-nanometer scale imaging capability of structure and chemistry have been widely used to characterise various aspects of electronic and optoelectronic device structures such as InGaAs quantum dots, InGaAs pseudomorphic (pHEMT) and metamorphic (mHEMT) layers and the ohmic metallisation of GaAs and GaN high electron mobility transistors, nichrome thin film resistors, GaN heteroepitaxy on sapphire and silicon substrates, as well as InAs and GaN nanowires. They also established convergent beam electron diffraction techniques for determination of lattice distortions in III-V compound semiconductors, EBSD for crystalline misorientation studies of GaN epilayers and high-angle annular dark field techniques coupled with digital image analysis for the mapping of composition and strain in the nanometric layered structures. Also, in-situ SEM experiments were performed on ohmic metallisation of pHEMT device structures. The established electron microscopy expertise for electronic materials with demonstrated examples is presented
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