Data Mining - Concepts and Techniques.

International Journal of Computer and Applications

Several enabling technologies are being explored for the fifth-generation (5G) mobile system era. The aim is to evolve a cellular network that remarkably pushes forward the limits of legacy mobile systems across all dimensions of performance metrics. One dominant technology that consistently features in the list of the 5G enablers is the millimeter-wave (mmWave) massive multiple-input-multiple-output (massive MIMO) system. It shows potentials to significantly raise user throughput, enhance spectral and energy efficiencies and increase the capacity of mobile networks using the joint capabilities of the huge available bandwidth in the mmWave frequency bands and high multiplexing gains achievable with massive antenna arrays. In this survey, we present the preliminary outcomes of extensive research on mmWave massive MIMO (as research on this subject is still in the exploratory phase) and highlight emerging trends together with their respective benefits, challenges, and proposed solutions. The survey spans broad areas in the field of wireless communications, and the objective is to point out current trends, evolving research issues and future directions on mmWave massive MIMO as a technology that will open up new frontiers of services and applications for next-generation cellular networks.

Millimeter-Wave Massive MIMO Communication for Future Wireless Systems: A Survey

Kidney stone disease is a crystal concretion formed usually within the kidneys It is an increasing urological disorder of human health, affecting about 12% of the world population It has been associated with an increased risk of end-stage renal failure The etiology of kidney stone is multifactorial The most common type of kidney stone is calcium oxalate formed at Randall's plaque on the renal papillary surfaces The mechanism of stone formation is a complex process which results from several physicochemical events including supersaturation, nucleation, growth, aggregation, and retention of urinary stone constituents within tubular cells These steps are modulated by an imbalance between factors that promote or inhibit urinary crystallization It is also noted that cellular injury promotes retention of particles on renal papillary surfaces The exposure of renal epithelial cells to oxalate causes a signaling cascade which leads to apoptosis by p38 mitogen-activated protein kinase pathways Currently, there is no satisfactory drug to cure and/or prevent kidney stone recurrences Thus, further understanding of the pathophysiology of kidney stone formation is a research area to manage urolithiasis using new drugs Therefore, this review has intended to provide a compiled up-to-date information on kidney stone etiology, pathogenesis, and prevention approaches

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Kidney Stone Disease: An Update on Current Concepts

The endothelium is essential for the maintenance of vascular homeostasis. Central to this role is the production of endothelium-derived nitric oxide (EDNO), synthesized by the endothelial isoform of nitric oxide synthase (eNOS). Endothelial dysfunction, manifested as impaired EDNO bioactivity, is an important early event in the development of various vascular diseases, including hypertension, diabetes, and atherosclerosis. The degree of impairment of EDNO bioactivity is a determinant of future vascular complications. Accordingly, growing interest exists in defining the pathologic mechanisms involved. Considerable evidence supports a causal role for the enhanced production of reactive oxygen species (ROS) by vascular cells. ROS directly inactivate EDNO, act as cell-signaling molecules, and promote protein dysfunction, events that contribute to the initiation and progression of endothelial dysfunction. Increasing data indicate that strategies designed to limit vascular ROS production can restore endothelial function in humans with vascular complications. The purpose of this review is to outline the various ways in which ROS can influence endothelial function and dysfunction, describe the redox mechanisms involved, and discuss approaches for preventing endothelial dysfunction that may highlight future therapeutic opportunities in the treatment of cardiovascular disease.

Redox control of endothelial function and dysfunction: Molecular mechanisms and therapeutic opportunities

Activation of the NLRP3 Inflammasome in association with Calcium Oxalate crystal-induced Reactive Oxygen Species in kidneys

A major role of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase family of enzymes is to catalyze the production of superoxides and other reactive oxygen species (ROS). These ROS, in turn, play a key role as messengers in cell signal transduction and cell cycling, but when they are produced in excess they can lead to oxidative stress (OS). Oxidative stress in the kidneys is now considered a major cause of renal injury and inflammation, giving rise to a variety of pathological disorders. In this review, we discuss the putative role of oxalate in producing oxidative stress via the production of reactive oxygen species by isoforms of NADPH oxidases expressed in different cellular locations of the kidneys. Most renal cells produce ROS, and recent data indicate a direct correlation between upregulated gene expressions of NADPH oxidase, ROS, and inflammation. Renal tissue expression of multiple NADPH oxidase isoforms most likely will impact the future use of different antioxidants and NADPH oxidase inhibitors to minimize OS and renal tissue injury in hyperoxaluria-induced kidney stone disease.

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NADPH Oxidase as a Therapeutic Target for Oxalate Induced Injury in Kidneys

Context. Rapid variations in optical flux are seen in many quasars and all blazars. The amount of variability in different classes of active galactic nuclei has been studied extensively but many questions remain unanswered. Aims. We present the results of a long-term programme to investigate the intra-night optical variability (INOV) of powerful flat spectrum radio core-dominated quasars (CDQs), with a focus on probing the relationship of INOV to the degree of optical polarization. Methods. We observed a sample of 16 bright CDQs showing strong broad optical emission lines and consisting of both high and low optical polarization quasars (HPCDQs and LPCDQs). In this first systematic study of its kind, we employed the 104-cm Sampurnanand telescope, the 201-cm Himalayan Chandra telescope and the 200-cm IUCAA-Girawali Observatory telescope, to carry out R-band monitoring on a total of 47 nights. Using the CCD as an N-star photometer to densely monitor each quasar for a minimum duration of about 4 h per night, INOV exceeding ∼1‐2 per cent could be reliably detected. Combining these INOV data with those taken from the literature, after ensuring conformity with the basic selection criteria we adopted for the 16 CDQs monitored by us, we were able to increase the sample size to 21 CDQs (12 LPCDQs and 9 HPCDQs) monitored on a total of 73 nights. Results. As the existence of a prominent flat-spectrum radio core signifies that strong relativistic beaming is present in all these CDQs, the definitions of the two sets differ primarily in fractional optical polarization, with the LPCDQs showing a very low median Pop � 0.4 per cent. Our study yields an INOV duty cycle (DC) of ∼28 per cent for the LPCDQs and ∼68 percent for HPCDQs. If only strong INOV with fractional amplitude above 3 per cent is considered, the corresponding DCs are ∼7 per cent and ∼40 per cent, respectively. Conclusions. From this strong contrast between the two classes of luminous, relativistically beamed quasars, it is apparent that relativistic beaming is normally not a sufficient condition for strong INOV and a high optical polarization is the other necessary condition. Moreover, the correlation is found to persist for many years after the polarization measurements were made. Some possible implications of this result are pointed out, particularly in the context of the recently detected rapid γ-ray variability of blazars.

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Intra-night optical variability of core dominated radio quasars: the role of optical polarization

Osteogenic changes in kidneys of hyperoxaluric rats

We used an unbiased approach of gene expression profiling to determine differential gene expression of all the macromolecular modulators (MMs) considered to be involved in stone formation, in hyperoxaluric rats, with and without treatment with the NADPH oxidase inhibitor apocynin. Male rats were fed rat chow or chow supplemented with 5% wt/wt hydroxy-l-proline (HLP) with or without apocynin-supplemented water. After 28 days, rats were euthanized and their kidneys explanted. Total RNA was isolated and microarray analysis was conducted using the Illumina bead array reader. Gene ontology analysis and the pathway analyses of the genes were done using Database for Annotation, Visualization of Integrated Discovery enrichment analysis tool. Quantitative RT-PCR of selected genes was carried out to verify the microarray results. Expression of selected gene products was confirmed using immunohistochemistry. Administration of HLP led to crystal deposition. Genes encoding for fibronectin, CD 44, fetuin B, osteopontin, and matrix-gla protein were upregulated while those encoding for heavy chains of inter-alpha-inhibitor 1, 3, and 4, calgranulin B, prothrombin, and Tamm-Horsfall protein were downregulated. HLP-fed rats receiving apocynin had a significant reversal in gene expression profiles: those that were upregulated came down while those that were downregulated stepped up. Apocynin treatment resulted in near complete absence of crystals. Clearly, there are two types of MMs; one is downregulated while the other is upregulated during hyperoxaluria and crystal deposition. Apparently gene and protein expressions of known macromolecular modulators of CaOx crystallization are likely regulated by ROS produced in part through the activation of NADPH oxidase.

Regulation of Macromolecular Modulators of Urinary Stone Formation by Reactive Oxygen Species: Transcriptional Study in an Animal Model of Hyperoxaluria

Sunil Joshi

Papers

Activation of the NLRP3 Inflammasome in association with Calcium Oxalate crystal-induced Reactive Oxygen Species in kidneys

NADPH Oxidase as a Therapeutic Target for Oxalate Induced Injury in Kidneys

Intra-night optical variability of core dominated radio quasars: the role of optical polarization

Osteogenic changes in kidneys of hyperoxaluric rats

Regulation of Macromolecular Modulators of Urinary Stone Formation by Reactive Oxygen Species: Transcriptional Study in an Animal Model of Hyperoxaluria