High Efficiency Video Coding (HEVC) is designed to deliver a video communication with better quality at reduced bit rate. For intra coding, HEVC employs an effective hierarchical quad tree ...partitioning and an exhaustive optimal mode search which increases the time complexity. Aiming this issue, we propose a Support Vector Machine (SVM)-based method to effectively predict the intra mode. Compared to the standard HEVC encoder HM-15.0, the proposed method could reduce 57.6% of encoding time at a bit-rate penalty of 3.3% at an average PSNR decline of only around 0.09 dB.
We investigate the stellar masses of strongly barred spiral galaxies. Our analysis is based on a sample of {approx}14,000 visually classified nearby galaxies given by Nair and Abraham. The fraction ...of barred spiral galaxies is found to be a strong function of stellar mass and star formation history, with a minimum near the characteristic mass at which bimodality is seen in the stellar populations of galaxies. We also find that bar fractions are very sensitive to the central concentration of galaxies below the transition mass but not above it. This suggests that whatever process is causing the creation of the red and blue sequences is either influencing, or being influenced by, structural changes which manifest themselves in the absence of bars. As a consequence of strong bar fractions being sensitive to the mass range probed, our analysis helps resolve discrepant results on the reported evolution of bar fractions with redshift.
Introduction
Rhinosinusitis disability index (RSDI) questionnaire is used to assess the severity of chronic rhinosinusitis (CRS) from the patient’s perspective. The severity of CRS can be measured ...objectively with the endoscope and computed tomogram (CT) using the Lund-Kennedy endoscopic score and Mackay-Lund scores respectively. The objective of the study is to evaluate whether baseline RSDI and Lund-Kennedy (LK) endoscopy scoring can help predict the Mackay-Lund CT (MKLCT) scores after medical treatment in patients with CRS.
Methodology
This is a prospective, observational study, carried out from 1st October 2017 to 30th September 2019 in the ENT out- patient department at a tertiary hospital in Northern India. 90 patients diagnosed with CRS were enrolled consecutively in the study. RSDI questionnaire was filled out for all the participants. They all underwent a diagnostic endoscopy and CRS was graded according to the Lund-Kennedy endoscopic scores. All participants were given medical treatment. Patients underwent CT of the paranasal sinuses after medical treatment and the MLKCT scores were calculated. The baseline RSDI and Lund-Kennedy scores were correlated with the MKLCT scores using Spearman’s Rank correlation tests. The diagnostic ability of the RSDI and LK endoscopy scores to predict the least MKLCT scores was compared using the receiver operator characteristics curves (ROC).
Results
A statistically significant correlation was seen with LK endoscopy scores and MKLCT scores (
r
= 0.396,
p
< 0.001) Among the individual parameters of the LK endoscopy scores only the polyp score had a statistically significant correlation with MKLCT scores (
r
= 0.593,
p
< 0.001). A weak negative correlation (
r
= − 0.058,
p
= 0.586) was seen between the RSDI scores and MKLCT scores. AUC in ROC curves for a LK endoscopy scores and RSDI scores were 0.690 and 0.462 respectively. Cut-off for predicting a MKLCT score of one or more for RSDI score was 25, with a sensitivity of 61% and specificity of 38.5%. Similarly, the cut-off for LK endoscopic score was 4.5, with a sensitivity of 68.8% and specificity of 61.5%.
Conclusion
Statistically significant (
p
< 0.001) association was found between baseline Lund-Kennedy endoscopic scores and Mackay-Lund CT scores post medical treatment. No significant association was found between RSDI scores and Mackay-Lund CT scores. ROC analysis indicated that Lund- Kennedy endoscopy score is a more accurate tool than RSDI score to predict a Mackay-Lund CT scores after medical treatment.
Introduction: International frontal sinus anatomy classification (IFAC) was introduced in 2016 to standardize the nomenclature of the cells in the frontal recess region, facilitate better ...communication between surgeons and precision in surgical planning, and improve surgical teaching. This study aims to estimate the radiological prevalence of the different frontal recess cells according to the IFAC and to evaluate the relationship of these cells with the frontal sinus opacification in patients with chronic rhinosinusitis. Methods: In this study, 90 participants diagnosed with chronic rhinosinusitis (CRS) who underwent computed tomogram (CT) of the para nasal sinuses were enrolled consecutively. The CT images were were studied in detail using RadiAnt DICOM viewer. The frontal recess cells were grouped as per the IFAC guidelines and their respective prevalence was calculated. The frontal recess cells were grouped as per the Opacification or mucosal thickening within these cells and the frontal sinuses were noted. A multivariate logistic regression analysis was done to evaluate the association between frontal sinus opacification and presence of various IFAC cells. Results: A total of 640 IFAC cells were documented in 180 sides, of which 326 were anterior cells, 263 were posterior cells and 51 were medial cells. The most prevalent cell was the agger nasi cells(ANC), present in 91.7% of 180 sides, the supra agger nasi cells(SANC), Supra agger nasi frontal cells(SAFC), supra bulla cells(SBC), supra bulla frontal cells(SBFC), supra orbital ethmoidal cells(SOEC) and frontal septal cells(FSC) were present in 47.8%,37.8%, 65.6%,28.9%, 51.1% and 28.3% respectively. There was no significant association of presence of IFAC cells and frontal sinus opacification except for SBFC(
p
= 0.038). A significantly higher number of diseased frontal recess cells were seen with involved frontal sinuses when compared with non-involved frontal sinuses across all types of IFAC cells. Conclusion: The ANC were the most prevalent among all the IFAC cells and the FSC were the least prevalent. There was no significant association with the presence of different types of IFAC cells and frontal sinus opacification except for SBFC. However, there was a significantly higher number of diseased IFAC cells associated with frontal sinus opacification than in those without frontal sinus opacification.
Abstract
We investigate the role of galaxy mergers in triggering active galactic nuclei (AGN) in the nearby universe. Our analysis is based on a sample of 79 post-merger remnant galaxies with deep ...X-ray observations from Chandra/XMM-Newton capable of detecting a low-luminosity AGN of ≥10
40.5
erg s
−1
. This sample is derived from a visually classified, volume-limited sample of 807 post-mergers identified in the Sloan Digital Sky Survey Data Release 14 with log
M
*
/
M
⊙
≥ 10.5 and 0.02 ≤
z
≤ 0.06. We find that the X-ray AGN fraction in this sample is 55.7% ± 5.6% compared to 23.6% ± 2.8% for a mass- and redshift-matched noninteracting control sample. The multiwavelength AGN fraction (identified as an AGN in one of X-ray, IR, radio or optical diagnostics) for post-mergers is 76.6% ± 4.8% compared to 39.1% ± 3.2% for controls. Thus post-mergers exhibit a high overall AGN fraction with an excess between 2 and 4 depending on the AGN diagnostics used. In addition, we find most optical, IR, and radio AGN are also identified as X-ray AGN while a large fraction of X-ray AGN are not identified in any other diagnostic. This highlights the importance of deep X-ray imaging to identify AGN. We find that the X-ray AGN fraction of post-mergers is independent of the stellar mass above log
M
*
/
M
⊙
≥ 10.5 unlike the trend seen in control galaxies. Overall, our results show that post-merger galaxies are a good tracer of the merger–AGN connection and strongly support the theoretical expectations that mergers trigger AGN.
The existence of high- z overmassive supermassive black holes represents a major conundrum in our understanding of black hole evolution. In this Letter, we probe from the observational point of view ...how early Universe environmental conditions could have acted as an evolutionary mechanism for the accelerated growth of the first black holes. Under the assumption that the early Universe is dominated by dwarf galaxies, we investigate the hypothesis that dwarf–dwarf galaxy interactions trigger black hole accretion. We present the discovery of 82 dwarf–dwarf galaxy pairs and 11 dwarf galaxy groups using the Hubble Space Telescope, doubling existing samples. The dwarf systems span a redshift range of 0.13 < z < 1.5, and a stellar mass range of 7.24 < log( M _* / M _⊙ ) < 9.73. We performed an X-ray study of a subset of these dwarf systems with Chandra and detected six new active galactic nuclei (AGN), increasing the number of known dwarf–dwarf-merger-related AGN from one to seven. We then compared the frequency of these AGN in grouped/paired dwarfs to that of isolated dwarfs and found a statistically significant enhancement (4 σ –6 σ ) in the interacting sample. This study, the first of its kind at the lowest mass scales, implies that the presence of a nearby dwarf neighbor is efficient in triggering black hole accretion. These results open new avenues for indirect studies of the emergence of the first supermassive black holes.
Absorption-line spectroscopy of multiply-lensed QSOs near a known foreground galaxy provides a unique opportunity to go beyond the traditional one-dimensional application of QSO probes and establish ...a crude three-dimensional map of halo gas around the galaxy that records the line-of-sight velocity field at different locations in the gaseous halo. Two intermediate-redshift galaxies are targeted in the field around the quadruply-lensed QSO HE 0435−1223 at redshift z = 1.689, and absorption spectroscopy along each of the lensed QSOs is carried out in the vicinities of these galaxies. One galaxy is a typical, star-forming L
* galaxy at z = 0.4188 and projected distance of ρ = 50 kpc from the lensing galaxy. The other is a super-L
* barred spiral at z = 0.7818 and ρ = 33 kpc. Combining known orientations of the quadruply-lensed QSO to the two foreground galaxies with the observed Mg ii λλ2796, 2803 absorption profiles along individual QSO sightlines has for the first time led to spatially resolved kinematics of tenuous halo gas on scales of 5–10 kpc at z > 0.2. A Mg ii absorber is detected in every sightline observed through the haloes of the two galaxies, and the recorded absorber strength is typical of what is seen in previous close QSO–galaxy pair studies. While the multisightline study confirms the unity covering fraction of Mg ii absorbing gas at ρ < 50 kpc from star-forming discs, the galaxies also present two contrasting examples of complex halo gas kinematics. Different models, including a rotating disc, collimated outflows and gaseous streams from either accretion or tidal/ram-pressure stripping, are considered for comparisons with the absorption-line observations, and infalling streams/stripped gas of width ≳10 kpc are found to best describe the observed gas kinematics across multiple sightlines. In addition, the observed velocity dispersion between different sightlines offers a crude estimate of turbulence in the Mg ii absorbing halo gas. The observations presented here demonstrate that multiple-QSO probes enable studies of spatially resolved gas kinematics around distant galaxies, which provide key insights into the physical nature of circumgalactic gas beyond the nearby Universe.
A biocompatible natural polysaccharide (PSP001) isolated from the fruit rind of
Punica granatum
was conjugated with L-cysteine (Y) to be used as a skeleton for the fabrication of fluorescent gold ...nanoclusters (AuNCs) represented as PSP-Y-AuNCs. With an average size of ~ 6 nm, PSP-Y-AuNCs demonstrated high quantum yield (31%), with a pH-sensitive fluorescence emission behavior. An emission maximum of 520 nm was obtained at acidic pH, which was blue shifted with increasing pH. This feature provides the possibilities for accurate ratiometric pH imaging. The PSP-Y-AuNCs not only demonstrated excellent biocompatibility with cancer cells and isolated peripheral lymphocytes and red blood cells but also demonstrated to be an active molecular imaging probe with appealing cellular uptake efficiency. The investigations with BALB/c mice further confirmed the non-toxic nature and in vivo imaging potential of the AuNCs. Estimation of the bio-distribution on solid tumor bearing syngeneic murine models revealed a tumor-targeted enhanced fluorescence emission pattern which is attributed to the pH responsive fluorescence behavior and the acidic microenvironment of the tumor. These findings were further confirmed with an impressive tumor accumulation pattern displayed in a xenograft of human cancer bearing nude mice. On account of their impressive biocompatibility and photophysical features, PSP-Y-AuNCs can exploited for the real-time fluorescence imaging of cancer tissues.
Graphical abstract
Fluorescent gold nanoclusters (PSP-Y-AuNCs) fabricated using a non-toxic natural polysaccharide (PSP001) demonstrated pH sensitive fluorescence emission pattern. The increased fluorescence readouts at acidic conditions and excellent biocompatibility made the PSP-Y-AuNCs an appealing candidate for in vivo tumor imaging applications.
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