20 research outputs found
An efficient source localization method in presence of multipath using smart antenna system
In this paper, a MATLAB based smart antenna testbed that efficiently localizes the line-of-sight (LOS) source in the presence of multipath signals is developed. By exploiting the consistent amplitude nature of the LOS signal, a variant of Constant Modulus Algorithm, namely Multitarget-Least Square Constant Modulus Algorithm is employed to adapt and update the weights of the smart antenna for estimation of the direction-of-arrival (DOA) of the of the LOS and multipath interference signals. Performance is compared with the conventional and recently proposed algorithms in the same testbed with alike considerations. Simulation result shows that the proposed method of DOA estimation performs better in terms of probability of resolution and root mean square error
An Efficient Source Localization Method in Presence of Multipath using Smart Antenna System
1069-1073In this paper, a MATLAB based smart antenna testbed that efficiently localizes the line-of-sight (LOS) source in the presence of multipath signals is developed. By exploiting the consistent amplitude nature of the LOS signal, a variant of Constant Modulus Algorithm, namely Multitarget-Least Square Constant Modulus Algorithm is employed to adapt and update the weights of the smart antenna for estimation of the direction-of-arrival (DOA) of the of the LOS and multipath interference signals. Performance is compared with the conventional and recently proposed algorithms in the same testbed with alike considerations. Simulation result shows that the proposed method of DOA estimation performs better in terms of probability of resolution and root mean square error
Improvement in hot corrosion resistance of dissimilar alloy 825 and AISI 321 CO2-laser weldment by HVOF coating in aggressive salt environment at 900°C
This study investigated the hot corrosion performance of a dissimilar weldment of Ni-based superalloy and stainless steel joined by CO2-laser welding and improved by high-velocity oxy-fuel (HVOF) coating in a Na2SO4-60wt%V2O5 environment at 900°C. A dissimilar butt joint of AISI 321 and alloy 825 was fabricated by CO2-laser welding with low heat input after obtaining the optimum welding parameters by bead-on-plate trials. The metallurgical and mechanical properties of the laser weldment were evaluated. The tensile test results indicated the occurrence of fracture in the base metal AISI 321 side. The HVOF process was employed to coat Ni-20wt%Cr on the weldment. To evaluate the surface morphology of the corrosion products formed on the uncoated and Ni-20wt%Cr-coated weldments, scanning electron microscopy (SEM) analysis was performed. Energy-dispersive spectroscopy (EDS) was used to determine the different elements present on the surface scales. The existence of oxide phases on the weldments was determined by X-ray diffraction (XRD). The cross sections of the weldments were characterized by SEM with EDS line mapping analysis. The results indicated that the Ni-20wt%Cr-coated weldment exhibited superior hot corrosion resistance due to the development of Cr2O3 and NiCr2O4 protective oxide scales
High monocytic MDSC signature predicts multi-drug resistance and cancer relapse in non-Hodgkin lymphoma patients treated with R-CHOP
IntroductionNon-Hodgkin Lymphoma (NHL) is a heterogeneous lymphoproliferative malignancy with B cell origin. Combinatorial treatment of rituximab, cyclophsphamide, hydroxydaunorubicin, oncovin, prednisone (R-CHOP) is the standard treatment regimen for NHL, yielding a complete remission (CR) rate of 40-50%. Unfortunately, considerable patients undergo relapse after CR or initial treatment, resulting in poor clinical implications. Patient’s response to chemotherapy varies widely from static disease to cancer recurrence and later is primarily associated with the development of multi-drug resistance (MDR). The immunosuppressive cells within the tumor microenvironment (TME) have become a crucial target for improving the therapy efficacy. However, a better understanding of their involvement is needed for distinctive response of NHL patients after receiving chemotherapy to design more effective front-line treatment algorithms based on reliable predictive biomarkers.MethodsPeripheral blood from 61 CD20+ NHL patients before and after chemotherapy was utilized for immunophenotyping by flow-cytometry at different phases of treatment. In-vivo and in-vitro doxorubicin (Dox) resistance models were developed with murine Dalton’s lymphoma and Jurkat/Raji cell-lines respectively and impact of responsible immune cells on generation of drug resistance was studied by RT-PCR, flow-cytometry and colorimetric assays. Gene silencing, ChIP and western blot were performed to explore the involved signaling pathways.ResultsWe observed a strong positive correlation between elevated level of CD33+CD11b+CD14+CD15- monocytic MDSCs (M-MDSC) and MDR in NHL relapse cohorts. We executed the role of M-MDSCs in fostering drug resistance phenomenon in doxorubicin-resistant cancer cells in both in-vitro, in-vivo models. Moreover, in-vitro supplementation of MDSCs in murine and human lymphoma culture augments early expression of MDR phenotypes than culture without MDSCs, correlated well with in-vitro drug efflux and tumor progression. We found that MDSC secreted cytokines IL-6, IL-10, IL-1β are the dominant factors elevating MDR expression in cancer cells, neutralization of MDSC secreted IL-6, IL-10, IL-1β reversed the MDR trait. Moreover, we identified MDSC secreted IL-6/IL-10/IL-1β induced STAT1/STAT3/NF-κβ signaling axis as a targeted cascade to promote early drug resistance in cancer cells.ConclusionOur data suggests that screening patients for high titre of M-MDSCs might be considered as a new potential biomarker and treatment modality in overcoming chemo-resistance in NHL patients
Dopamine Regulates Angiogenesis in Normal Dermal Wound Tissues
Cutaneous wound healing is a normal physiological process and comprises different phases. Among these phases, angiogenesis or new blood vessel formation in wound tissue plays an important role. Skin is richly supplied by sympathetic nerves and evidences indicate the significant role of the sympathetic nervous system in cutaneous wound healing. Dopamine (DA) is an important catecholamine neurotransmitter released by the sympathetic nerve endings and recent studies have demonstrated the potent anti-angiogenic action of DA, which is mediated through its D2 DA receptors. We therefore postulate that this endogenous catecholamine neurotransmitter may have a role in the neovascularization of dermal wound tissues and subsequently in the process of wound healing. In the present study, the therapeutic efficacy of D2 DA receptor antagonist has been investigated for faster wound healing in a murine model of full thickness dermal wound. Our results indicate that treatment with specific D2 DA receptor antagonist significantly expedites the process of full thickness normal dermal wound healing in mice by inducing angiogenesis in wound tissues. The underlined mechanisms have been attributed to the up-regulation of homeobox transcription factor HoxD3 and its target α5β1 integrin, which play a pivotal role in wound angiogenesis. Since D2 DA receptor antagonists are already in clinical use for other disorders, these results have significant translational value from the bench to the bedside for efficient wound management along with other conventional treatment modalities
Dopamine Regulates Mobilization of Mesenchymal Stem Cells during Wound Angiogenesis
Angiogenesis is an important step in the complex biological and molecular events leading to successful healing of dermal wounds. Among the different cellular effectors of wound angiogenesis, the role of mesenchymal stem cells (MSCs) is of current interest due to their transdifferentiation and proangiogenic potentials. Skin is richly innervated by sympathetic nerves which secrete dopamine (DA) and we have recently shown that concentration of DA present in synaptic cleft can significantly inhibit wound tissue neovascularization. As recent reports indicate that MSCs by mobilizing into wound bed play an important role in promoting wound angiogenesis, we therefore investigated the effect of DA on the migration of MSCs in wound tissues. DA acted through its D2 receptors present in the MSCs to inhibit their mobilization to the wound beds by suppressing Akt phosphorylation and actin polymerization. In contrast, this inhibitory effect of DA was reversed after treatment with specific DA D2 receptor antagonist. Increased mobilization of MSCs was demonstrated in the wound site following blockade of DA D2 receptor mediated actions, and this in turn was associated with significantly more angiogenesis in wound tissues. This study is of translational value and indicates use of DA D2 receptor antagonists to stimulate mobilization of these stem cells for faster regeneration of damaged tissues
Association of common genetic polymorphisms with plasma lipid and coronary artery disease in West Bengal population
529-535Both apolipoprotein B (APOB) and low-density lipoprotein receptor (LDL-R) play crucial role in LDL uptake by cells. The association of apob MspI polymorphism and ldl-r AvaII polymorphism with coronary artery disease (CAD) has already been reported in other populations. Genetic variations in these two gene locus is associated with CAD in West Bengal population was investigated here. Blood samples were collected from angiographically proven 254 CAD patients and age matched 246 healthy people (controls) from different districts of West Bengal, India. Serum lipids including total cholesterol (TC), triglycerides (TG), high density lipid-cholesterol (HDL-C), low density lipid-cholesterol (LDL-C) and very low density lipid-cholesterol (VLDL-C) were evaluated in all the subjects. Genotyping was performed by PCR-RFLP combined with gel electrophoresis. The lipid-profile analysis revealed that TC, TG, LDL-C and VLDL-C were significantly high (p ) in patients than controls. Genotyping study showed that homozygous A+A+ genotype was significantly more prevalent (22% vs 10%, p = 0.0011) among patient group in this population than control. This genotype was also associated with higher LDL-C and TC levels. But there was no significant association of genotypes with serum lipid concentration was evident in APOB gene. The A+A+ genotype could be a genetic marker for CAD
PeopleSansPeople: A Synthetic Data Generator for Human-Centric Computer Vision
In recent years, person detection and human pose estimation have made great
strides, helped by large-scale labeled datasets. However, these datasets had no
guarantees or analysis of human activities, poses, or context diversity.
Additionally, privacy, legal, safety, and ethical concerns may limit the
ability to collect more human data. An emerging alternative to real-world data
that alleviates some of these issues is synthetic data. However, creation of
synthetic data generators is incredibly challenging and prevents researchers
from exploring their usefulness. Therefore, we release a human-centric
synthetic data generator PeopleSansPeople which contains simulation-ready 3D
human assets, a parameterized lighting and camera system, and generates 2D and
3D bounding box, instance and semantic segmentation, and COCO pose labels.
Using PeopleSansPeople, we performed benchmark synthetic data training using a
Detectron2 Keypoint R-CNN variant [1]. We found that pre-training a network
using synthetic data and fine-tuning on various sizes of real-world data
resulted in a keypoint AP increase of ( vs. )
for few-shot transfer (limited subsets of COCO-person train [2]), and an
increase of ( vs. ) for abundant real data
regimes, outperforming models trained with the same real data alone. We also
found that our models outperformed those pre-trained with ImageNet with a
keypoint AP increase of ( vs. ) for few-shot
transfer and ( vs. ) for abundant real data
regimes. This freely-available data generator should enable a wide range of
research into the emerging field of simulation to real transfer learning in the
critical area of human-centric computer vision.Comment: PeopleSansPeople template Unity environment, benchmark binaries, and
source code is available at:
https://github.com/Unity-Technologies/PeopleSansPeopl
Familial aggregation of autoimmune thyroiditis in first-degree relatives of patients with juvenile autoimmune thyroid disease
Several studies have shown aggregation of autoimmune thyroiditis in families by estimation of thyroid antibodies. However, the prevalence by concurrent estimation with Fine-needle Aspiration Cytology (FNAC) and thyroid antibodies has not been previously reported. We therefore studied 222 first-degree relatives (group 1) of 71 index cases diagnosed as lymphocytic thyroiditis on FNAC and 81 family members (group 2) of 23 goitrous children diagnosed as colloid goiter on FNAC for comparison. Successful FNAC conducted in 122 group 1 subjects revealed lymphocytic thyroiditis in 51 (42%), whereas lymphocytic thyroiditis was diagnosed in only 5 goitrous subjects (13%) in group 2. Among group 1 subjects with FNAC-proven lymphocytic thyroiditis, antithyroid peroxidase (TPO) antibodies were found in 35 (67%), while in anti-TPO antibody positive goitrous relatives of group 1, lymphocytic thyroiditis was found in 36 (78%). Eight new cases of overt hypothyroidism and 45 new cases of subclinical hypothyroidism were diagnosed among group 1 subjects. Our study suggests: (1) familial clustering of autoimmune thyroiditis; (2) if only FNAC or thyroid antibodies is used for diagnosis of autoimmune thyroiditis in children, 22%–33% of cases are likely to be missed; and (3) serum thyrotropin (TSH) should be offered to all first-degree relatives of patients with juvenile autoimmune thyroiditis