Rohan Lal - Profile on Academia.edu (original) (raw)
Papers by Rohan Lal
Novel Image and Its Compressed Image Based on VVC Standard, Pair Data Set for Deep Learning Image and Video Compression Applications
ELFI 2019 Poster
Existing light-field cameras are susceptible to produce low-quality results as sensor noise can d... more Existing light-field cameras are susceptible to produce low-quality results as sensor noise can dominate measurements. Thus, denoising is a critical step in the light-field (LF) subsequent analysis and processing. This paper presents a novel LF denoising framework based on an adaptive parallax and auto-regressive model analysis. The novel procedure first creates a view-dependent LF stack by compensating parallax variation employing an extended variational flow technique on a set of LF intensity and depth features. Further, it takes advantage of the spatial similarity across the registered LFs stack and reduce the noisy observations. The output is, further, improved by formulating the denoising as a novel adaptive autoregressive (AR) stochastic problem. The proposed convex AR model averaged view-specific spatial energies of stacked LF images on Riemannian manifolds by a depth-directed maximum likelihood AR parameter estimation process. Lastly, scale intensity of refined AR LF predicted view by the average intensity of the superpixel in each LF stacked image. The experiments show that proposed AR LF denoiser outperforms standard algorithms in terms of visual quality and in the preservation of parallax details.
A Novel Convex Autoregressive Model for Light Field Denoising on Riemannian Space
Existing light field cameras are susceptible to produce low-quality results as sensor noise can d... more Existing light field cameras are susceptible to produce low-quality results as sensor noise can dominate measurements. Thus, denoising is a critical step in the light field (LF) subsequent analysis and processing. This paper presents a novel LF denoising framework based on an adaptive parallax and auto-regressive model analysis. The novel procedure first creates a view-dependent LF stack by compensating parallax variation employing an extended variational flow technique on a set of LF intensity and depth features. Further, it takes advantage of the spatial similarity across the registered LF stack and reduce the noisy observations. The output is, further, improved by formulating the denoising as a novel adaptive autoregressive (AR) stochastic problem. The proposed convex AR model averaged view-specific spatial energies of stacked LF images on Riemannian manifolds by a depth-directed maximum likelihood AR parameter estimation process. Lastly, scale intensity of refined AR LF predicted view by the average intensity of the superpixel in each LF stacked image. The experiments show that proposed AR LF denoiser outperforms standard algorithms in terms of visual quality and in preservation of parallax details.
A Rich Stereoscopic 3D High Dynamic Range Image & Video Database of Natural Scenes
2019 International Conference on 3D Immersion (IC3D), 2019
The consumer market of High Dynamic Range (HDR) displays and cameras is blooming rapidly with the... more The consumer market of High Dynamic Range (HDR) displays and cameras is blooming rapidly with the advent of 3D video and display technologies. Specialised agencies like Moving Picture Experts Group and International Telecommunication Union are demanding the standardization of latest display advancements. Lack of sufficient experimental data is a major bottleneck for the development of preliminary research efforts in 3D HDR video technology. We propose to make publicly available to the research community, a diversified database of Stereoscopic 3D HDR images and videos, captured within the beautiful campus of Indian Institute of Technology, Madras, which is blessed with rich flora and fauna, and is home to several rare wildlife species. Further, we have described the procedure of capturing, aligning, calibrating and post-processing of 3D images and videos. We have discussed research opportunities and challenges, and the potential use cases of HDR stereo 3D applications and depth-from-HDR aspects.
Scorpion Kaliotoxin Reverses Hyperkalemia, High Serum [K+ ], in Skeletal Muscle
Cell Biology: Research & Therapy, 2018
Scorpion toxin causes symptoms such as nausea, muscle twitching, and tachycardia. Kaliotoxin, a s... more Scorpion toxin causes symptoms such as nausea, muscle twitching, and tachycardia. Kaliotoxin, a scorpion toxin, inhibits voltagegated and leak potassium channels, making cells less excitable. Excess potassium ions increase cell excitability and allow an action potential to occur at a lower threshold voltage. To determine the effects of high [K+] and kaliotoxin, action potential thresholds were measured. Under hyperkalemic conditions, threshold voltage was reduced significantly (p<<0.01) from mean control values. When exposed to high [K+], muscle contraction force showed a significant increase (p=0.03) from control, 1.60g (+/- 0.877; n=5), to 2.56g (+/-1.82; n=5). In the presence of kaliotoxin and hyperkalemic solution, muscle contraction force showed a significant increase (p<<0.01) from 2.07g (+/- 2.07; n=10) to 7.82g (+/- 5.11; n=10) and the latent period showed a significant decrease (p=0.28) from a control value of 0.04s (+/- 0.04; n=10) to 0.03 (+/- 0.03; n=10). Hyperkalemic solutions decreased the threshold level significantly (p<<0.01) while scorpion kaliotoxin, diluted in hyperkalemic solution, allowed the threshold voltage to significantly surpass (p<0.01) normal levels. Scorpion kaliotoxins reduced K+ channel activation and can return cell excitability, under hyperkalemic conditions, to normal. Scorpion kaliotoxin is a potential treatment to reverse the effects of hyperkalemia.
Critical Ultrasound Journal, 2010
IntroductionPoint of care (POC) ultrasound brings another powerful dimension to the physical exam... more IntroductionPoint of care (POC) ultrasound brings another powerful dimension to the physical examination of the critically ill. A contemporary challenge for all care providers, however, is how to best incorporate ultrasound into contemporary algorithms of care. When POC ultrasound corroborates pre-examination clinical suspicion, incorporation of the findings into decision-making is easier. When POC ultrasound generates new or unexpected findings, decision-making may be more difficult, especially with conditions that were previously not appreciated with older diagnostic technologies. Pneumothoraces (PTXs), previously seen only on computed tomography and not on supine chest radiographs known as occult pneumothoraces (OPTXs), which are now increasingly appreciated on POC ultrasound, are such an example.MethodsThe relevant literature concerning POC ultrasound and PTXs was reviewed after an electronic search using PubMed supplemented by ongoing research by the Canadian Trauma Trials Coll...
The Journal of Trauma: Injury, Infection, and Critical Care, 2006
Background: Conventional fluid resuscitation with Ringer's lactated (RL) activates neutrophils an... more Background: Conventional fluid resuscitation with Ringer's lactated (RL) activates neutrophils and causes end-organ damage. We have previously shown that HSPTX, a combination of small volume hypertonic saline (HS) and pentoxifylline (PTX), a phosphodiesterase-inhibitor, downregulates in vitro neutrophil activation and proinflammatory mediator synthesis. Herein, we hypothesized that HSPTX decreases end-organ injury when compared with RL in an animal model of hemorrhagic shock. Methods: Sprague-Dawley rats were bled to a mean arterial pressure of 35 mm Hg for 1 hour. Animals were divided into 3 groups: sham (no shock, no resuscitation, n ؍ 7), RL (32 mL/kg, n ؍ 7), and HSPTX (7.5% NaCl 4 mL/kg ؉ PTX 25 mg/kg; n ؍ 7). Shed blood was infused after fluid resuscitation. Blood pressure was monitored until the end of resuscita-tion. Animals were sacrificed at 24 hour after resuscitation. Bronchoalveolar lavage fluid (BALF) was obtained for white cell count (total and differential) and TNF-␣ and IL-1 levels were measured by ELISA. Lung and intestinal injury at 24 hour were evaluated by histopathology. Organ damage was graded by a pathologist and a score was created (0 ؍ no injury; 3 ؍ severe). Lung neutrophil infiltration was evaluated by MPO immune staining. Results: There were no differences in mean arterial pressure between groups. At 24 hours, BALF leukocyte count was decreased by 30% in HSPTX animals (p < 0.01). TNF-␣ and IL-1 levels were markedly decreased in HSPTX-resuscitated animals compared with their RL counterparts (p < 0.01). HSPTX-resuscitated animals (lung injury score ؍ 1.0 ؎ 0.4) had markedly decreased acute lung injury compared with RL-treated animals (2.5 ؎ 0.3) (p < 0.01). RL resuscitation led to a two-fold increase in lung neutrophil infiltration whereas in HSPTX-treated animals, the number of MPO ؉ cells was similar to sham animals (p < 0.001). Intestinal injury was markedly attenuated by HSPTX (1.1 ؎ 0.3) compared with RL animals (2.6 ؎ 0.4) (p < 0.001). Conclusions: HSPTX, a small volume resuscitation strategy with marked immunomodulatory potential led to a marked decrease in end-organ damage. HSPTX is an attractive alternative to RL in hemorrhagic shock resuscitation.
Journal of Surgical Research, 2006
Background. Neutrophils play a major role as the first line in host defense after exposure to bac... more Background. Neutrophils play a major role as the first line in host defense after exposure to bacterial products. However, an exaggerated inflammatory response characterized by overwhelming neutrophil activation can be injurious to the host. Pentoxifylline (PTX), a nonspecific phosphodiesterase inhibitor, has been shown to attenuate neutrophil oxidative burst and decrease proinflammatory mediator synthesis. We hypothesized that PTX down-regulates neutrophil activation by decreasing the surface expression of both CD35 and CD66b, two markers of neutrophil degranulation. Materials and methods. Venous blood was obtained from three healthy volunteers. Whole blood was incubated with HBSS (control), f-methionyl-leucyl-phenylalanine (fMLP, 1 M/L), PTX (2 mM/L), or fMLP ؉ PTX. CD35 and CD66b expression were measured by flow cytometry. Results. fMLP treatment caused a significant increase in CD35 and CD66b expression of when compared to controls (P < 0.01). PTX treatment revealed expression of both markers comparable to the control group. A 38% decrease in CD35 (64 ؎ 12 versus 100; P < 0.01) and a 52% decrease in CD66b (48 ؎ 7 versus 100; P < 0.01) expression were demonstrated in the fMLP ؉ PTX group when compared to fMLP alone. Conclusion. In addition to the known effects of PTX on neutrophil oxidative burst, PTX also affects neutrophil degranulation, an essential step in enzyme release and subsequent tissue injury. These findings may have clinical relevance in the treatment of disease processes due to inflammation in which primed neutrophils play a role.
Surgery, 2006
Background.-Blood transfusion is a risk factor for many inflammatory processes. Its supernatant f... more Background.-Blood transfusion is a risk factor for many inflammatory processes. Its supernatant fraction has been proven to activate neutrophils. We hypothesized that pentoxifylline (PTX) would attenuate stored bloodinduced neutrophil activation and pro-inflammatory mediator production. Methods.-Whole blood was incubated with HBSS, LPS (100 µg/mL), leukoreduced PRBC supernatant ϩ LPS, or supernatant ϩ LPS ϩ PTX (2 mmol/L). TNF-␣ levels were measured by ELISA. MMP-9 was evaluated with zymography. Neutrophil CD66b expression was determined by flow cytometry in blood treated with HBSS, fMLP (1 µmol/L), supernatant ϩ fMLP, or supernatant ϩ fMLP ϩ PTX. Results.-TNF-␣ levels were elevated in both the LPS and supernatant ϩ LPS groups (100%; P < 0.01 and 120%; P < 0.01, respectively). PTX administration resulted in a 106% decrease in TNF-␣ (P < 0.0001). MMP-9 levels were increased in all groups. Administration of PTX to the supernatant ϩ LPS group generated a 33% decrease in MMP-9 levels, which was not statistically significant (P < 0.4). Upregulation of CD66b expression was seen in LPS and supernatant ϩ LPS groups. Significant attenuation was seen with PTX (47%; P < 0.01). Conclusions.-PTX downregulates CD66b and TNF-␣ expression in supernatant-induced whole blood. Because blood transfusion can contribute to inflammatory injury, the adjunctive use of PTX may have therapeutic potential. ᭤ The transfusion of allogeneic packed red blood cells (PBRCs) is well-known to be associated with systemic inflammatory responses, including transfusion-related acute lung injury and other remote organ-related reactions. These reactions are associated with neutrophil activation and TNF-␣ increases. The authors have shown that treatment of leukoreduced PBRC units in vitro with the methylxanthine-derivative phosphodiesterase inhibitor PTX significantly reduced both TNF-␣ levels and CD66b expression, which is related to neutrophil degranulation activity. MMP-9 activity was not significantly affected. How in vitro PTX pretreatment compares with either pretransfusion washing of PBRCs or concomitant PTX infusion remains as a question. The authors noted an unexpected lack of a priming effect on neutrophil degranulation in these experiments, which may be attributable to the fact that they utilized 5% 50% 90% 100% 5% 50% 90% 100% Chapter 22-Transfusion Medicine and Coagulation Ͳ 377
A Novel Approach for Multi-View 3D HDR Content Generation via Depth Adaptive Cross Trilateral Tone Mapping
2019 International Conference on 3D Immersion (IC3D), 2019
In this work, we proposed a novel depth adaptive tone mapping scheme for stereo HDR imaging and 3... more In this work, we proposed a novel depth adaptive tone mapping scheme for stereo HDR imaging and 3D display. We are interested in the case where different exposures are taken from different viewpoints. The scheme employed a new depth-adaptive cross-trilateral filter (DA-CTF) for recovering High Dynamic Range (HDR) images from multiple Low Dynamic Range (LDR) images captured at different exposure levels. Explicitly leveraging additional depth information in the tone mapping operation correctly identify global contrast change and detail visibility change by preserving the edges and reducing halo artifacts in the synthesized 3D views by depth-image-based rendering (DIBR) procedure. The experiments show that the proposed DA-CTF and DIBR scheme outperforms state-of-the-art operators in the enhanced depiction of tone mapped HDR stereo images on LDR displays.
European Light Field Imaging Workshop (ELFI 2019), Borovets, Bulgaria, In European Signal Processing Conference (EUSIPCO) Proceedings, 2019
Existing light field cameras are susceptible to produce low-quality results as sensor noise can d... more Existing light field cameras are susceptible to produce low-quality
results as sensor noise can dominate measurements. Thus, denoising
is a critical step in the light field (LF) subsequent analysis and
processing. This paper presents a novel LF denoising framework
based on an adaptive parallax and auto-regressive model analysis.
The novel procedure first creates a view-dependent LF stack
by compensating parallax variation employing an extended variational
flow technique on a set of LF intensity and depth features.
Further, it takes advantage of the spatial similarity across the registered
LF stack and reduce the noisy observations. The output is,
further, improved by formulating the denoising as a novel adaptive
autoregressive (AR) stochastic problem. The proposed convex
AR model averaged view-specific spatial energies of stacked LF
images on Riemannian manifolds by a depth-directed maximum
likelihood AR parameter estimation process. Lastly, scale intensity
of refined AR LF predicted view by the average intensity of
the superpixel in each LF stacked image. The experiments show
that proposed AR LF denoiser outperforms standard algorithms in
terms of visual quality and in preservation of parallax details.
9th International Conference on 3D Immersion (IC3D 2019), Brussels, Belgium, 2019
The consumer market of High Dynamic Range (HDR) displays and cameras is blooming rapidly with the... more The consumer market of High Dynamic Range (HDR) displays
and cameras is blooming rapidly with the advent of
3D video and display technologies. Specialised agencies like
Moving Picture Experts Group and International Telecommunication
Union are demanding the standardization of latest
display advancements. Lack of sufficient experimental
data is a major bottleneck for the development of preliminary
research efforts in 3D HDR video technology. We propose
to make publicly available to the research community,
a diversified database of Stereoscopic 3D HDR images and
videos, captured within the beautiful campus of Indian Institute
of Technology, Madras, which is blessed with rich flora
and fauna, and is home to several rare wildlife species. Further,
we have described the procedure of capturing, aligning,
calibrating and post-processing of 3D images and videos. We
have discussed research opportunities and challenges, and the
potential use cases of HDR stereo 3D applications and depthfrom-
HDR aspects.
Conference Presentations by Rohan Lal
European Light Field Imaging Workshop, Borovets, Bulgaria (European Association for Signal Processing, EURASIP), 2019
Existing light-field cameras are susceptible to produce low-quality results as sensor noise can d... more Existing light-field cameras are susceptible to produce low-quality results as sensor noise can dominate measurements. Thus, denoising is a critical step in the light-field (LF) subsequent analysis and processing. This paper presents a novel LF denoising framework based on an adaptive parallax and auto-regressive model analysis. The novel procedure first creates a view-dependent LF stack by compensating parallax variation employing an extended variational flow technique on a set of LF intensity and depth features. Further, it takes advantage of the spatial similarity across the registered LFs stack and reduce the noisy observations. The output is, further, improved by formulating the denoising as a novel adaptive autoregressive (AR) stochastic problem. The proposed convex AR model averaged view-specific spatial energies of stacked LF images on Riemannian manifolds by a depth-directed maximum likelihood AR parameter estimation process. Lastly, scale intensity of refined AR LF predicted view by the average intensity of the superpixel in each LF stacked image. The experiments show that proposed AR LF denoiser outperforms standard algorithms in terms of visual quality and in the preservation of parallax details.
Novel Image and Its Compressed Image Based on VVC Standard, Pair Data Set for Deep Learning Image and Video Compression Applications
ELFI 2019 Poster
Existing light-field cameras are susceptible to produce low-quality results as sensor noise can d... more Existing light-field cameras are susceptible to produce low-quality results as sensor noise can dominate measurements. Thus, denoising is a critical step in the light-field (LF) subsequent analysis and processing. This paper presents a novel LF denoising framework based on an adaptive parallax and auto-regressive model analysis. The novel procedure first creates a view-dependent LF stack by compensating parallax variation employing an extended variational flow technique on a set of LF intensity and depth features. Further, it takes advantage of the spatial similarity across the registered LFs stack and reduce the noisy observations. The output is, further, improved by formulating the denoising as a novel adaptive autoregressive (AR) stochastic problem. The proposed convex AR model averaged view-specific spatial energies of stacked LF images on Riemannian manifolds by a depth-directed maximum likelihood AR parameter estimation process. Lastly, scale intensity of refined AR LF predicted view by the average intensity of the superpixel in each LF stacked image. The experiments show that proposed AR LF denoiser outperforms standard algorithms in terms of visual quality and in the preservation of parallax details.
A Novel Convex Autoregressive Model for Light Field Denoising on Riemannian Space
Existing light field cameras are susceptible to produce low-quality results as sensor noise can d... more Existing light field cameras are susceptible to produce low-quality results as sensor noise can dominate measurements. Thus, denoising is a critical step in the light field (LF) subsequent analysis and processing. This paper presents a novel LF denoising framework based on an adaptive parallax and auto-regressive model analysis. The novel procedure first creates a view-dependent LF stack by compensating parallax variation employing an extended variational flow technique on a set of LF intensity and depth features. Further, it takes advantage of the spatial similarity across the registered LF stack and reduce the noisy observations. The output is, further, improved by formulating the denoising as a novel adaptive autoregressive (AR) stochastic problem. The proposed convex AR model averaged view-specific spatial energies of stacked LF images on Riemannian manifolds by a depth-directed maximum likelihood AR parameter estimation process. Lastly, scale intensity of refined AR LF predicted view by the average intensity of the superpixel in each LF stacked image. The experiments show that proposed AR LF denoiser outperforms standard algorithms in terms of visual quality and in preservation of parallax details.
A Rich Stereoscopic 3D High Dynamic Range Image & Video Database of Natural Scenes
2019 International Conference on 3D Immersion (IC3D), 2019
The consumer market of High Dynamic Range (HDR) displays and cameras is blooming rapidly with the... more The consumer market of High Dynamic Range (HDR) displays and cameras is blooming rapidly with the advent of 3D video and display technologies. Specialised agencies like Moving Picture Experts Group and International Telecommunication Union are demanding the standardization of latest display advancements. Lack of sufficient experimental data is a major bottleneck for the development of preliminary research efforts in 3D HDR video technology. We propose to make publicly available to the research community, a diversified database of Stereoscopic 3D HDR images and videos, captured within the beautiful campus of Indian Institute of Technology, Madras, which is blessed with rich flora and fauna, and is home to several rare wildlife species. Further, we have described the procedure of capturing, aligning, calibrating and post-processing of 3D images and videos. We have discussed research opportunities and challenges, and the potential use cases of HDR stereo 3D applications and depth-from-HDR aspects.
Scorpion Kaliotoxin Reverses Hyperkalemia, High Serum [K+ ], in Skeletal Muscle
Cell Biology: Research & Therapy, 2018
Scorpion toxin causes symptoms such as nausea, muscle twitching, and tachycardia. Kaliotoxin, a s... more Scorpion toxin causes symptoms such as nausea, muscle twitching, and tachycardia. Kaliotoxin, a scorpion toxin, inhibits voltagegated and leak potassium channels, making cells less excitable. Excess potassium ions increase cell excitability and allow an action potential to occur at a lower threshold voltage. To determine the effects of high [K+] and kaliotoxin, action potential thresholds were measured. Under hyperkalemic conditions, threshold voltage was reduced significantly (p<<0.01) from mean control values. When exposed to high [K+], muscle contraction force showed a significant increase (p=0.03) from control, 1.60g (+/- 0.877; n=5), to 2.56g (+/-1.82; n=5). In the presence of kaliotoxin and hyperkalemic solution, muscle contraction force showed a significant increase (p<<0.01) from 2.07g (+/- 2.07; n=10) to 7.82g (+/- 5.11; n=10) and the latent period showed a significant decrease (p=0.28) from a control value of 0.04s (+/- 0.04; n=10) to 0.03 (+/- 0.03; n=10). Hyperkalemic solutions decreased the threshold level significantly (p<<0.01) while scorpion kaliotoxin, diluted in hyperkalemic solution, allowed the threshold voltage to significantly surpass (p<0.01) normal levels. Scorpion kaliotoxins reduced K+ channel activation and can return cell excitability, under hyperkalemic conditions, to normal. Scorpion kaliotoxin is a potential treatment to reverse the effects of hyperkalemia.
Critical Ultrasound Journal, 2010
IntroductionPoint of care (POC) ultrasound brings another powerful dimension to the physical exam... more IntroductionPoint of care (POC) ultrasound brings another powerful dimension to the physical examination of the critically ill. A contemporary challenge for all care providers, however, is how to best incorporate ultrasound into contemporary algorithms of care. When POC ultrasound corroborates pre-examination clinical suspicion, incorporation of the findings into decision-making is easier. When POC ultrasound generates new or unexpected findings, decision-making may be more difficult, especially with conditions that were previously not appreciated with older diagnostic technologies. Pneumothoraces (PTXs), previously seen only on computed tomography and not on supine chest radiographs known as occult pneumothoraces (OPTXs), which are now increasingly appreciated on POC ultrasound, are such an example.MethodsThe relevant literature concerning POC ultrasound and PTXs was reviewed after an electronic search using PubMed supplemented by ongoing research by the Canadian Trauma Trials Coll...
The Journal of Trauma: Injury, Infection, and Critical Care, 2006
Background: Conventional fluid resuscitation with Ringer's lactated (RL) activates neutrophils an... more Background: Conventional fluid resuscitation with Ringer's lactated (RL) activates neutrophils and causes end-organ damage. We have previously shown that HSPTX, a combination of small volume hypertonic saline (HS) and pentoxifylline (PTX), a phosphodiesterase-inhibitor, downregulates in vitro neutrophil activation and proinflammatory mediator synthesis. Herein, we hypothesized that HSPTX decreases end-organ injury when compared with RL in an animal model of hemorrhagic shock. Methods: Sprague-Dawley rats were bled to a mean arterial pressure of 35 mm Hg for 1 hour. Animals were divided into 3 groups: sham (no shock, no resuscitation, n ؍ 7), RL (32 mL/kg, n ؍ 7), and HSPTX (7.5% NaCl 4 mL/kg ؉ PTX 25 mg/kg; n ؍ 7). Shed blood was infused after fluid resuscitation. Blood pressure was monitored until the end of resuscita-tion. Animals were sacrificed at 24 hour after resuscitation. Bronchoalveolar lavage fluid (BALF) was obtained for white cell count (total and differential) and TNF-␣ and IL-1 levels were measured by ELISA. Lung and intestinal injury at 24 hour were evaluated by histopathology. Organ damage was graded by a pathologist and a score was created (0 ؍ no injury; 3 ؍ severe). Lung neutrophil infiltration was evaluated by MPO immune staining. Results: There were no differences in mean arterial pressure between groups. At 24 hours, BALF leukocyte count was decreased by 30% in HSPTX animals (p < 0.01). TNF-␣ and IL-1 levels were markedly decreased in HSPTX-resuscitated animals compared with their RL counterparts (p < 0.01). HSPTX-resuscitated animals (lung injury score ؍ 1.0 ؎ 0.4) had markedly decreased acute lung injury compared with RL-treated animals (2.5 ؎ 0.3) (p < 0.01). RL resuscitation led to a two-fold increase in lung neutrophil infiltration whereas in HSPTX-treated animals, the number of MPO ؉ cells was similar to sham animals (p < 0.001). Intestinal injury was markedly attenuated by HSPTX (1.1 ؎ 0.3) compared with RL animals (2.6 ؎ 0.4) (p < 0.001). Conclusions: HSPTX, a small volume resuscitation strategy with marked immunomodulatory potential led to a marked decrease in end-organ damage. HSPTX is an attractive alternative to RL in hemorrhagic shock resuscitation.
Journal of Surgical Research, 2006
Background. Neutrophils play a major role as the first line in host defense after exposure to bac... more Background. Neutrophils play a major role as the first line in host defense after exposure to bacterial products. However, an exaggerated inflammatory response characterized by overwhelming neutrophil activation can be injurious to the host. Pentoxifylline (PTX), a nonspecific phosphodiesterase inhibitor, has been shown to attenuate neutrophil oxidative burst and decrease proinflammatory mediator synthesis. We hypothesized that PTX down-regulates neutrophil activation by decreasing the surface expression of both CD35 and CD66b, two markers of neutrophil degranulation. Materials and methods. Venous blood was obtained from three healthy volunteers. Whole blood was incubated with HBSS (control), f-methionyl-leucyl-phenylalanine (fMLP, 1 M/L), PTX (2 mM/L), or fMLP ؉ PTX. CD35 and CD66b expression were measured by flow cytometry. Results. fMLP treatment caused a significant increase in CD35 and CD66b expression of when compared to controls (P < 0.01). PTX treatment revealed expression of both markers comparable to the control group. A 38% decrease in CD35 (64 ؎ 12 versus 100; P < 0.01) and a 52% decrease in CD66b (48 ؎ 7 versus 100; P < 0.01) expression were demonstrated in the fMLP ؉ PTX group when compared to fMLP alone. Conclusion. In addition to the known effects of PTX on neutrophil oxidative burst, PTX also affects neutrophil degranulation, an essential step in enzyme release and subsequent tissue injury. These findings may have clinical relevance in the treatment of disease processes due to inflammation in which primed neutrophils play a role.
Surgery, 2006
Background.-Blood transfusion is a risk factor for many inflammatory processes. Its supernatant f... more Background.-Blood transfusion is a risk factor for many inflammatory processes. Its supernatant fraction has been proven to activate neutrophils. We hypothesized that pentoxifylline (PTX) would attenuate stored bloodinduced neutrophil activation and pro-inflammatory mediator production. Methods.-Whole blood was incubated with HBSS, LPS (100 µg/mL), leukoreduced PRBC supernatant ϩ LPS, or supernatant ϩ LPS ϩ PTX (2 mmol/L). TNF-␣ levels were measured by ELISA. MMP-9 was evaluated with zymography. Neutrophil CD66b expression was determined by flow cytometry in blood treated with HBSS, fMLP (1 µmol/L), supernatant ϩ fMLP, or supernatant ϩ fMLP ϩ PTX. Results.-TNF-␣ levels were elevated in both the LPS and supernatant ϩ LPS groups (100%; P < 0.01 and 120%; P < 0.01, respectively). PTX administration resulted in a 106% decrease in TNF-␣ (P < 0.0001). MMP-9 levels were increased in all groups. Administration of PTX to the supernatant ϩ LPS group generated a 33% decrease in MMP-9 levels, which was not statistically significant (P < 0.4). Upregulation of CD66b expression was seen in LPS and supernatant ϩ LPS groups. Significant attenuation was seen with PTX (47%; P < 0.01). Conclusions.-PTX downregulates CD66b and TNF-␣ expression in supernatant-induced whole blood. Because blood transfusion can contribute to inflammatory injury, the adjunctive use of PTX may have therapeutic potential. ᭤ The transfusion of allogeneic packed red blood cells (PBRCs) is well-known to be associated with systemic inflammatory responses, including transfusion-related acute lung injury and other remote organ-related reactions. These reactions are associated with neutrophil activation and TNF-␣ increases. The authors have shown that treatment of leukoreduced PBRC units in vitro with the methylxanthine-derivative phosphodiesterase inhibitor PTX significantly reduced both TNF-␣ levels and CD66b expression, which is related to neutrophil degranulation activity. MMP-9 activity was not significantly affected. How in vitro PTX pretreatment compares with either pretransfusion washing of PBRCs or concomitant PTX infusion remains as a question. The authors noted an unexpected lack of a priming effect on neutrophil degranulation in these experiments, which may be attributable to the fact that they utilized 5% 50% 90% 100% 5% 50% 90% 100% Chapter 22-Transfusion Medicine and Coagulation Ͳ 377
A Novel Approach for Multi-View 3D HDR Content Generation via Depth Adaptive Cross Trilateral Tone Mapping
2019 International Conference on 3D Immersion (IC3D), 2019
In this work, we proposed a novel depth adaptive tone mapping scheme for stereo HDR imaging and 3... more In this work, we proposed a novel depth adaptive tone mapping scheme for stereo HDR imaging and 3D display. We are interested in the case where different exposures are taken from different viewpoints. The scheme employed a new depth-adaptive cross-trilateral filter (DA-CTF) for recovering High Dynamic Range (HDR) images from multiple Low Dynamic Range (LDR) images captured at different exposure levels. Explicitly leveraging additional depth information in the tone mapping operation correctly identify global contrast change and detail visibility change by preserving the edges and reducing halo artifacts in the synthesized 3D views by depth-image-based rendering (DIBR) procedure. The experiments show that the proposed DA-CTF and DIBR scheme outperforms state-of-the-art operators in the enhanced depiction of tone mapped HDR stereo images on LDR displays.
European Light Field Imaging Workshop (ELFI 2019), Borovets, Bulgaria, In European Signal Processing Conference (EUSIPCO) Proceedings, 2019
Existing light field cameras are susceptible to produce low-quality results as sensor noise can d... more Existing light field cameras are susceptible to produce low-quality
results as sensor noise can dominate measurements. Thus, denoising
is a critical step in the light field (LF) subsequent analysis and
processing. This paper presents a novel LF denoising framework
based on an adaptive parallax and auto-regressive model analysis.
The novel procedure first creates a view-dependent LF stack
by compensating parallax variation employing an extended variational
flow technique on a set of LF intensity and depth features.
Further, it takes advantage of the spatial similarity across the registered
LF stack and reduce the noisy observations. The output is,
further, improved by formulating the denoising as a novel adaptive
autoregressive (AR) stochastic problem. The proposed convex
AR model averaged view-specific spatial energies of stacked LF
images on Riemannian manifolds by a depth-directed maximum
likelihood AR parameter estimation process. Lastly, scale intensity
of refined AR LF predicted view by the average intensity of
the superpixel in each LF stacked image. The experiments show
that proposed AR LF denoiser outperforms standard algorithms in
terms of visual quality and in preservation of parallax details.
9th International Conference on 3D Immersion (IC3D 2019), Brussels, Belgium, 2019
The consumer market of High Dynamic Range (HDR) displays and cameras is blooming rapidly with the... more The consumer market of High Dynamic Range (HDR) displays
and cameras is blooming rapidly with the advent of
3D video and display technologies. Specialised agencies like
Moving Picture Experts Group and International Telecommunication
Union are demanding the standardization of latest
display advancements. Lack of sufficient experimental
data is a major bottleneck for the development of preliminary
research efforts in 3D HDR video technology. We propose
to make publicly available to the research community,
a diversified database of Stereoscopic 3D HDR images and
videos, captured within the beautiful campus of Indian Institute
of Technology, Madras, which is blessed with rich flora
and fauna, and is home to several rare wildlife species. Further,
we have described the procedure of capturing, aligning,
calibrating and post-processing of 3D images and videos. We
have discussed research opportunities and challenges, and the
potential use cases of HDR stereo 3D applications and depthfrom-
HDR aspects.
European Light Field Imaging Workshop, Borovets, Bulgaria (European Association for Signal Processing, EURASIP), 2019
Existing light-field cameras are susceptible to produce low-quality results as sensor noise can d... more Existing light-field cameras are susceptible to produce low-quality results as sensor noise can dominate measurements. Thus, denoising is a critical step in the light-field (LF) subsequent analysis and processing. This paper presents a novel LF denoising framework based on an adaptive parallax and auto-regressive model analysis. The novel procedure first creates a view-dependent LF stack by compensating parallax variation employing an extended variational flow technique on a set of LF intensity and depth features. Further, it takes advantage of the spatial similarity across the registered LFs stack and reduce the noisy observations. The output is, further, improved by formulating the denoising as a novel adaptive autoregressive (AR) stochastic problem. The proposed convex AR model averaged view-specific spatial energies of stacked LF images on Riemannian manifolds by a depth-directed maximum likelihood AR parameter estimation process. Lastly, scale intensity of refined AR LF predicted view by the average intensity of the superpixel in each LF stacked image. The experiments show that proposed AR LF denoiser outperforms standard algorithms in terms of visual quality and in the preservation of parallax details.