32 research outputs found

    Brain Tumor Segmentation and Identification Using Particle Imperialist Deep Convolutional Neural Network in MRI Images

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    For the past few years, segmentation for medical applications using Magnetic Resonance (MR) images is concentrated. Segmentation of Brain tumors using MRIpaves an effective platform to plan the treatment and diagnosis of tumors. Thus, segmentation is necessary to be improved, for a novel framework. The Particle Imperialist Deep Convolutional Neural Network (PI-Deep CNN) suggested framework is intended to address the problems with segmenting and categorizing the brain tumor. Using the Density-Based Spatial Clustering of Applications with Noise (DBSCAN) Algorithm, the input MRI brain image is segmented, and then features are extracted using the Scatter Local Neighborhood Structure (SLNS) descriptor. Combining the scattering transform and the Local Neighborhood Structure (LNS) descriptor yields the proposed descriptor. A suggested Particle Imperialist algorithm-trained Deep CNN is then used to achieve the tumor-level classification. Different levels of the tumor are classified by the classifier, including Normal without tumor, Abnormal, Malignant tumor, and Non-malignant tumor. The cell is identified as a tumor cell and is subjected to additional diagnostics, with the exception of the normal cells that are tumor-free. The proposed method obtained a maximum accuracy of 0.965 during the experimentation utilizing the BRATS database and performance measures

    A study of feto-maternal outcome in case of premature rupture of membrane at a tertiary care center

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    Background: Premature rupture of membranes is the rupture of the fetal membranes in the absence of uterine contraction or before the onset of labor. When this occurs before 37 weeks of gestation, it is termed as preterm premature rupture of membranes. Management depends upon gestational age and the presence of complicating factors. An accurate assessment of gestational age and knowledge of the maternal, fetal and neonatal risks are essential to appropriate evaluation, counselling, and care of patients with PROM. The purpose of the study is timely diagnosis and appropriate management of the cases of PROM and PPROM to improve maternal and neonatal outcomes. Methods: A Prospective study was performed at the department of obstetrics and gynecology, at a tertiary care center from August 2020 to December 2021. A clinical data sheet was made for recording all information about the pregnant women after taking their consent. And their maternal and neonatal outcomes were recorded. Results: a total of 150 cases of PROM and PPROM were taken during our study out of which 53.33% belong to the younger age group, 43.33% were primi gravida, 66.66% belonged to the lower socioeconomic class, 25.33% had a previous history of abortion followed by dilatation and evacuation, rate of cesarean delivery was 34.66% and rate of NICU admission of neonates was 15.78% and 57.87% babies had low birth weight and rate of stillbirth was 1.97%. whereas 34.66% of cases had various complications related to PROM. Conclusions: Individualized management of PROM cases depending on the gestational age and risk of complications and antibiotic coverage is the best way to achieve a good fetomaternal outcome

    The Seoul National University AGN Monitoring Project. IV. Hα Reverberation Mapping of Six AGNs and the Hα Size–Luminosity Relation

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    The broad-line region (BLR) size–luminosity relation has paramount importance for estimating the mass of black holes in active galactic nuclei (AGNs). Traditionally, the size of the Hβ BLR is often estimated from the optical continuum luminosity at 5100 Å, while the size of the Hα BLR and its correlation with the luminosity is much less constrained. As a part of the Seoul National University AGN Monitoring Project, which provides 6 yr photometric and spectroscopic monitoring data, we present our measurements of the Hα lags of high-luminosity AGNs. Combined with the measurements for 42 AGNs from the literature, we derive the size–luminosity relations of the Hα BLR against the broad Hα and 5100 Å continuum luminosities. We find the slope of the relations to be 0.61 ± 0.04 and 0.59 ± 0.04, respectively, which are consistent with the Hβ size–luminosity relation. Moreover, we find a linear relation between the 5100 Å continuum luminosity and the broad Hα luminosity across 7 orders of magnitude. Using these results, we propose a new virial mass estimator based on the Hα broad emission line, finding that the previous mass estimates based on scaling relations in the literature are overestimated by up to 0.7 dex at masses lower than 107M⊙

    The Seoul National University AGN Monitoring Project III: Hβ\beta lag measurements of 32 luminous AGNs and the high-luminosity end of the size--luminosity relation

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    We present the main results from a long-term reverberation mapping campaign carried out for the Seoul National University Active Galactic Nuclei (AGN) Monitoring Project. High-quality data were obtained during 2015-2021 for 32 luminous AGNs (i.e., continuum luminosity in the range of 10444610^{44-46} erg s1^{-1}) at a regular cadence, of 20-30 days for spectroscopy and 3-5 days for photometry. We obtain time lag measurements between the variability in the Hβ\beta emission and the continuum for 32 AGNs; twenty-five of those have the best lag measurements based on our quality assessment, examining correlation strength, and the posterior lag distribution. Our study significantly increases the current sample of reverberation-mapped AGNs, particularly at the moderate to high luminosity end. Combining our results with literature measurements, we derive a Hβ\beta broad line region size--luminosity relation with a shallower slope than reported in the literature. For a given luminosity, most of our measured lags are shorter than the expectation, implying that single-epoch black hole mass estimators based on previous calibrations could suffer large systematic uncertainties.Comment: Accepted by ApJ; 39 pages, 22 figure

    The Seoul National University AGN Monitoring Project IV: Hα\alpha reverberation mapping of 6 AGNs and the Hα\alpha Size-Luminosity Relation

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    The broad line region (BLR) size-luminosity relation has paramount importance for estimating the mass of black holes in active galactic nuclei (AGNs). Traditionally, the size of the Hβ\beta BLR is often estimated from the optical continuum luminosity at 5100\angstrom{} , while the size of the Hα\alpha BLR and its correlation with the luminosity is much less constrained. As a part of the Seoul National University AGN Monitoring Project (SAMP) which provides six-year photometric and spectroscopic monitoring data, we present our measurements of the Hα\alpha lags of 6 high-luminosity AGNs. Combined with the measurements for 42 AGNs from the literature, we derive the size-luminosity relations of Hα\alpha BLR against broad Hα\alpha and 5100\angstrom{} continuum luminosities. We find the slope of the relations to be 0.61±0.040.61\pm0.04 and 0.59±0.040.59\pm0.04, respectively, which are consistent with the \hb{} size-luminosity relation. Moreover, we find a linear relation between the 5100\angstrom{} continuum luminosity and the broad Hα\alpha luminosity across 7 orders of magnitude. Using these results, we propose a new virial mass estimator based on the Hα\alpha broad emission line, finding that the previous mass estimates based on the scaling relations in the literature are overestimated by up to 0.7 dex at masses lower than 10710^7~M_{\odot}.Comment: Accepted for publication in ApJ (Jun. 25th, 2023). 21 pages, 12 figure

    Impact of an International Nosocomial Infection Control Consortium multidimensional approach on central line-associated bloodstream infection rates in adult intensive care units in eight cities in India

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    SummaryObjectiveTo evaluate the impact of the International Nosocomial Infection Control Consortium (INICC) multidimensional infection control approach on central line-associated bloodstream infection (CLABSI) rates in eight cities of India.MethodsThis was a prospective, before-and-after cohort study of 35650 patients hospitalized in 16 adult intensive care units of 11 hospitals. During the baseline period, outcome surveillance of CLABSI was performed, applying the definitions of the CDC/NHSN (US Centers for Disease Control and Prevention/National Healthcare Safety Network). During the intervention, the INICC approach was implemented, which included a bundle of interventions, education, outcome surveillance, process surveillance, feedback on CLABSI rates and consequences, and performance feedback. Random effects Poisson regression was used for clustering of CLABSI rates across time periods.ResultsDuring the baseline period, 9472 central line (CL)-days and 61 CLABSIs were recorded; during the intervention period, 80898 CL-days and 404 CLABSIs were recorded. The baseline rate was 6.4 CLABSIs per 1000 CL-days, which was reduced to 3.9 CLABSIs per 1000 CL-days in the second year and maintained for 36 months of follow-up, accounting for a 53% CLABSI rate reduction (incidence rate ratio 0.47, 95% confidence interval 0.31–0.70; p=0.0001).ConclusionsImplementing the six components of the INICC approach simultaneously was associated with a significant reduction in the CLABSI rate in India, which remained stable during 36 months of follow-up

    Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

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    Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

    Stabilization of ravines: case study of Sabarmati river, Gujarat State, India

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    by Prajakta Jadhav and Amit Prashan

    Permanent displacement based seismic design chart for cantilever retaining walls

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    We analyze and optimize the performance of coupled plasmonic nanoantennas for refractive index sensing. The investigated structure supports a sub- and a superradiant mode that originates in the weak coupling of a dipolar and a quadrupolar mode, resulting in a Fano-type spectral lineshape. In our study, we vary the near-field coupling of the two modes and particularly examine the influence of the spectral detuning between them on the sensing performance. Surprisingly, the case of matched resonance frequencies does not provide the best sensor. Instead, we find that the right amount of coupling strength and spectral detuning allows for achieving the ideal combination of narrow linewidth and sufficient excitation strength of the subradiant mode, and therefore results in an optimized sensor performance. Our findings are confirmed by experimental results and first-order perturbation theory. The latter is based on the resonant state expansion and provides direct access to resonance frequency shifts and linewidth changes as well as the excitation strength of the modes. Based on these parameters, we define a figure of merit that can be easily calculated for different sensing geometries and agrees well with the numerical and experimental results.by Prajakta Jadhav, Mohit Singh and Amit Prashan
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