Rizwan Ahmad - Academia.edu (original) (raw)

Papers by Rizwan Ahmad

Blood, 2008

Among the patients with bone marrow hypoplasia, differentiating aplastic anemia (AA) from hypopla... more Among the patients with bone marrow hypoplasia, differentiating aplastic anemia (AA) from hypoplastic myelodysplastic syndrome (HMDS) can be a difficult and challenging task because of the considerable clinical, cytological and histological similarities between these two disorders. The distinction between AA and HMDS is important because the clinical course and management of these two entities differ. There is a higher risk of progression to acute leukemia in patients with HMDS compared with AA. Various attempts have been made in the past to differentiate these entities. Different patterns of proliferation of bone marrow cells in AA and HMDS have been reported in past using proliferating cell nuclear antigens (PCNA). S-Phase Fraction (SPF) reflects the cellular proliferation and has been proven to be a useful diagnostic and prognostic marker in various hematological malignancies and solid tumors. In the present study, we examined whether flow cytometric analysis of SPF could be used...

2009 4th International Symposium on Wireless Pervasive Computing, 2009

Abstract Due to their popularity, dense deployments of wireless local area networks (WLANs) are b... more Abstract Due to their popularity, dense deployments of wireless local area networks (WLANs) are becoming a common feature of many cities around the world. However, with only a limited number of channels available, the problem of increased interference can severely degrade the performance of WLANs if an effective channel assignment scheme is not employed. Previous studies on channel assignment in WLANs almost always assume that all access points (AP) employ the same channel assignment scheme which is clearly ...

Gastroenterology, 2013

CDC5L expression was found in the nuclei of normal murine intestinal epithelial cells. Areas of t... more CDC5L expression was found in the nuclei of normal murine intestinal epithelial cells. Areas of the colonic epithelium in AhCre + Apc fl/fl and Apc Min/+ mice which showed evidence of Wnt signalling by nuclear localisation of beta catenin showed increased nuclear expression of SFRS2 and cytoplasmic localisation of CDC5L. CDC5L knockdown in HCT116 and HT29 cells resulted in significant inhibition of cell proliferation by both SRB and clonogenic assays (p,0.05). SFRS2 knockdown also resulted in increased nuclear expression of CDC5L in these cell lines. The malignant colonic lesions that developed in Apc Min/+ Pten-/mice showed loss of nuclear beta catenin expression and reversal of the phenotype observed in Apc Min/+ mice, with nuclear CDC5L localisation once again. Conclusion Apc inactivation results in increased nuclear expression of SFRS2 in colonic epithelial cells in vivo. This coincides with translocation of CDC5L from the nucleus into the cytoplasm, which limits its ability to regulate the cell cycle and splice pre-mRNA. Acquisition of an additional mutation in Pten alters Wnt signalling further, causing reduced nuclear accumulation of beta catenin and allowing CDC5L to translocate back into the nucleus, where it possibly stabilises the tumor phenotype.

The Journal of Physical Chemistry, 1982

layered intercalation compounds are in progress and the results will be reported in the near futu... more layered intercalation compounds are in progress and the results will be reported in the near future. rate constant for OH-is 5 times larger than that for C1-, while the value of the deintercalation rate constant for OHis 3 times smaller than that for C1-. This indicates that OH-may interact strongly with the solid host lattice in the layers of the Ni-HT(C1). Similar kinetic investigations in aqueous suspensions of Acknowledgment. We thank Kyowa Chemical Co. for the supply of the synthetic hydrotalcite-like compound and thank Mr. Shigeo Miyata for his useful suggestions. Mechanism of Reduction of Bis(2-hydroxyethyl) Trisulfide by eaq-and CO,-. Spectrum and Scavenglng of RSS. Radicals

Magnetic Resonance in Medicine, 2014

Purpose-For the application of compressive sensing to parallel MRI, Poisson disk sampling (PDS) h... more Purpose-For the application of compressive sensing to parallel MRI, Poisson disk sampling (PDS) has been shown to generate superior results compared with random sampling methods. However, due to its limited flexibility to incorporate additional constraints, PDS is not readily extendible to dynamic applications. Here, we propose and validate a pseudo-random sampling technique that allows incorporating constraints specific to dynamic imaging. Methods-The proposed sampling scheme, called variable density incoherent spatiotemporal acquisition (VISTA), is based on constrained minimization of Riesz energy on a spatiotemporal grid. Data from both a digital phantom and real-time cine were used to compare VISTA with uniform interleaved sampling (UIS) and variable density random sampling (VRS). The image quality was assessed qualitatively and quantitatively.

This paper analyzes the performance of Enhanced relay-enabled Distributed Coordination Function (... more This paper analyzes the performance of Enhanced relay-enabled Distributed Coordination Function (ErDCF) for wireless ad hoc networks under transmission errors. The idea of ErDCF is to use high data rate nodes to work as relays for the low data rate nodes. ErDCF achieves higher throughput and reduces energy consumption compared to IEEE 802.11 Distributed Coordination Function (DCF) in an ideal

2007 6th International Conference on Information, Communications & Signal Processing, 2007

Abstract The popularity of wireless local area networks (WLANs) has resulted in their dense deplo... more Abstract The popularity of wireless local area networks (WLANs) has resulted in their dense deployment in many cities around the world. The increased interference among different WLANs severely degrades the throughput achievable. This problem has been further exacerbated by the limited number of frequency channels available. An improved distributed and dynamic channel assignment scheme that is simple to implement and does not depend on the knowledge of the throughput function is proposed in this work. It also allows each ...

Health Physics, 2015

A miniature electron spin resonance (ESR) probehead that includes a static field source and a mic... more A miniature electron spin resonance (ESR) probehead that includes a static field source and a microwave resonator for in vivo measurement of paramagnetic defects in tooth enamel was developed. These defects are known to be a good marker for quantifying the ionizing radiation dose absorbed in teeth. The probehead has a typical length of just 30 mm and total weight of 220 g. The patient "bites" into the probehead while the measurement procedure is being carried out. The probehead operates in pulsed mode at a frequency of ∼11.2 GHz and supplies a static magnetic field of ∼400 mT. A detailed design of the probehead is provided together with its specifications in terms of measurement volume and signal-to-noise ratio for a typical sample. A specially developed simulation program was used to predict the spatial distribution of the acquired signal under conditions of grossly inhomogeneous static and RF fields. Experimental results with irradiated incisor teeth validated the probehead's sensitivity, being able to detect signals in tooth irradiated by only 2 Gy. Subject to additional improvements and tests, this type of probehead can potentially have significant clinical applications ranging from mass triage following major nuclear events to routine occupational evaluation of ionizing radiation absorbed over long periods of time.

2011 IEEE 4th International Conference on Cloud Computing, 2011

... servers, storage, applications,) that can be rapidly provisioned and released with minimal ma... more ... servers, storage, applications,) that can be rapidly provisioned and released with minimal management effort or service provider interaction. This cloud model promotes availability and is comprised of five key characteristics, three delivery models, and four deployment models”. ...

2009 IEEE 70th Vehicular Technology Conference Fall, 2009

Abstract-This paper analyzes the performance of Enhanced relay-enabled Distributed Coordination F... more Abstract-This paper analyzes the performance of Enhanced relay-enabled Distributed Coordination Function (ErDCF) for wireless ad hoc networks under transmission errors. The idea of ErDCF is to use high data rate nodes to work as relays for the low data rate nodes. ErDCF ...

VTC Spring 2008 - IEEE Vehicular Technology Conference, 2008

Abstract Due to its popularity, dense deployments of wireless local area networks (WLANs) are bec... more Abstract Due to its popularity, dense deployments of wireless local area networks (WLANs) are becoming a common feature of many cities around the world. However, with only a limited number of channels available, the problem of increased interference can severely degrade the performance of WLANs if an effective channel assignment scheme is not employed. In an earlier work, we proposed an improved asynchronous distributed and dynamic channel assignment scheme that (1) is simple to implement,(2) does not require ...

Agronomy for Sustainable Development, 2008

Composting provides an excellent way to manage the huge volume of organic waste and convert it in... more Composting provides an excellent way to manage the huge volume of organic waste and convert it into a useful soil amendment. The effectiveness of composted organic waste can be further improved by enriching and blending it with nutrients and biologically active substances. The resulting value-added composts can be used at substantially low rates such as a few hundred kg per ha compared with conventional use of organic wastes in tons per ha. This approach could have practical significance in reducing the use of chemical fertilizer for sustainable agriculture and the environment. L-tryptophan is a precursor of the growth hormone indole acetic acid and is known to stimulate plant growth at extremely low concentrations. Here, we studied the effect of composted fruit and vegetable wastes, enriched with N at 133 g kg −1 compost, with or without L-tryptophan at 10 mg kg −1 compost, on soil and maize crops. The enriched compost was applied at 300 kg ha −1 to a sandy clay loam soil either by mixing with the top 15-cm soil layer in pots or as a band placement along the maize plants grown in the field. The compost was applied alone and in combination with 40 or 80 kg ha −1 urea N and compared with a treatment containing 160 kg N ha −1 , a full dose of N fertilizer alone, while P and K fertilizers were applied in all the treatments. Our results show that application of the enriched compost to soil increased aggregate stability by up to 24.8% and water retention by up to 43.1% compared with untreated control. A gradual increase in the concentration of indole acetic acid in compost, ranging from 1.02 to 3.34 mg kg −1 , was observed when compost was treated with its precursor L-tryptophan. The results of pot and field experiments revealed that compost enriched with N and L-tryptophan in the presence of 80 kg N fertilizer significantly increased cob and grain yields, by up to 19.8 and 21.4%, respectively, compared with a full dose of N fertilizer. These findings suggest that enrichment of composted organic wastes with N and L-tryptophan can change them into a value-added organic product that could be used as a soil amendment at rates as low as 300 kg ha −1 to increase crop production on a sustainable basis.

Materials Letters, 2015

Fire-retarding materials are essential in order to fulfill the various requirements in our daily ... more Fire-retarding materials are essential in order to fulfill the various requirements in our daily life. Here we present the macro-porous self-setting aluminum trihydroxide (ATH) foams which were fabricated by a direct-foaming technique. Sodium dodecyl sulfate (SDS) was used as a surfactant. The microstructure of the foam was set immediately by the addition of ordinary Portland cement. The ATH foams obtained by this technique have cell size in the range of 50 to 180 mm and porosity in the range of 88 to 92%. Finally, the fire retarding capability of self-setting ATH foam was characterized by TGA/DSC.

Indian Journal of Clinical Biochemistry, 2013

Reactive oxygen species, as singlet oxygen (1 O 2), is continuously being generated by aerobic or... more Reactive oxygen species, as singlet oxygen (1 O 2), is continuously being generated by aerobic organisms, and react actively with biomolecules. At excessive amounts, 1 O 2 induces oxidative stress and shows carcinogenic and toxic effects due to oxidation of lipids, proteins and nucleic acids. In our study, immunoglobulin G (IgG) was modified by 1 O 2 generated by the ultraviolet (UV) irradiation of methylene blue. The modified IgG was characterized by UV spectroscopy, carbonyl content determination, thermal denaturation and electrophoretic study. Oxidation induced by modification of IgG by 1 O 2 also analyzed by scavenging studies. It was found that ultraviolet absorption spectra of modified IgG shows marked hyperchromicity. The carbonyl content was found to be high in modified IgG as compared to native IgG which confirms its oxidation. Thermal denaturation of modified protein sample shows decrease in Tm value by 3°C and less intensity banding pattern on polyacrylamide gel electrophoresis. The quenching effect of sodium azide provides clue for modification of IgG by methylene blue, as it is known 1 O 2 scavenger. Hence, the IgG modified with 1 O 2 may be one of the etiological pathogenic factors for rheumatoid arthritis and diabetes.

Communications in Computer and Information Science, 2010

Quality is an important consideration in the development of today's large complex software system... more Quality is an important consideration in the development of today's large complex software systems. Software architecture and quality play a vital role in the success or failure of any software system. Similarly to maintain the qualities of a software system during development and to adapt the quality attributes as the software requirements changes, software architecture is necessary. This paper discusses software quality attributes and the support provided by software architecture to achieve the desired quality. A novel Software Architecture Reuse and Evaluation framework is proposed on the basis of existing software architecture evaluation methods with respect to quality requirements. A case study is used for experimental validation of the ISARE. The results show that ISARE ensures the required level of quality requirements in the software architecture and automatable.

VTC Spring 2008 - IEEE Vehicular Technology Conference, 2008

Unlike the terrestrial wireless networks that utilize the radio channel, underwater networks use ... more Unlike the terrestrial wireless networks that utilize the radio channel, underwater networks use the acoustic channel, which poses research challenges in the medium access control (MAC) protocol design due to its low bandwidth and high propagation delay characteristics. Since most of the MAC protocols for wireless terrestrial networks have been designed with negligible propagation delay in mind, they generally perform poorly when applied directly in underwater acoustic networks, especially for the case of handshaking-based protocols. In this paper, we propose a MACA-based MAC protocol with packet train to multiple neighbors (MACA-MN). It improves the channel utilization by forming a train of packets destined for multiple neighbors during each round of handshake, which greatly reduces the relative proportion of time wasted due to the propagation delays of control packets. This approach also reduces the hidden terminal problem. Our simulations show that the MACA-MN is able to achieve much higher throughput than the MACA protocol.

Toxicology Mechanisms and Methods, 2008

ABSTRACT Peroxynitrite is a reactive oxidant produced from nitric oxide ((.)NO) and superoxide an... more ABSTRACT Peroxynitrite is a reactive oxidant produced from nitric oxide ((.)NO) and superoxide anion (O(2)(.-)). It is produced by the body in response to environmental toxins, stress, ultraviolet light, ischemia/reperfusion, inflammation, etc. In vivo, peroxynitrite is formed in macrophages, endothelial cells, platelets, leukocytes, and neurons. It reacts with a variety of biomolecules including proteins, lipids, and DNA. We have investigated the photochemical addition of lysine to native DNA in view of its potential importance in the photo-cross-linking of histones to DNA in chromatin. Lysine-and arginine-rich histone H1 in nucleosome on modification by physical, chemical, or environmental agents forms histone-DNA adducts. We have characterized the photoadducts by absorption, fluorescence, and chromatographic methods. The UV absorption spectra of the DNA-lysine photoadduct showed hyperchromism, indicating structural distortions in DNA either due to single-strand breaks or opening of the double helix at the site of lysine conjugation. On peroxynitrite treatment, the melting temperature (T(m)) of the DNA-lysine adduct increased by 15 degrees C compared to the native DNA-lysine adduct. A decrease in the fluorescence intensity of the DNA-lysine photoadduct with respect to the modified adduct was observed. The gel filtration profile of the peroxynitrite-modified adduct was also found to be different from that of the native DNA and DNA-lysine photoadduct. Hence, the peroxynitrite-modified photoadduct may have important implications in toxicology, mutagenesis, and carcinogenesis.

Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology, 2009

The oculocerebrorenal syndrome of Lowe (OCRL) is a rare X-linked recessive disorder, chiefly char... more The oculocerebrorenal syndrome of Lowe (OCRL) is a rare X-linked recessive disorder, chiefly characterized by ocular involvement, mental retardation, and kidney disease. A literature review is provided, detailing the diversity of oral anomalies associated with the OCRL syndrome. Reported abnormalities include delayed tooth eruption, odontogenic cyst formation, and constricted dental arches. In addition, we present an unusual case of an 18-year-old male affected with the OCRL syndrome and fetal alcohol syndrome. The oral radiographic examination was significant for multiple impacted permanent teeth, many with pericoronal radiolucencies, and an underdeveloped mandible.

Nucleosides, Nucleotides and Nucleic Acids, 2012

The aim of the study is the biochemical characterization of human DNA modified with arginine and ... more The aim of the study is the biochemical characterization of human DNA modified with arginine and peroxynitrite. In the present study, DNA was isolated from human blood cells and its adduct was formed with one of the amino acid, arginine. The DNA-arginine adduct was then modified with peroxynitrite, a reactive nitrogen species. The modified DNA adduct was characterized by ultraviolet (UV) absorption spectroscopy, thermal melting profile, and electrophoresis studies. UV spectroscopic analysis of the photoadduct showed hyperchromicity, indicating the formation of single-strand breaks and photomodification. Thermal denaturation studies of DNA-arginine adduct and peroxynitrite-modified adduct showed a decrease in the temperature (T(m)) value by 4.5°C and an increase in the T(m) of 8°C, respectively. Peroxynitrite modification is evident by an increase in the T(m) value and a change in the migration pattern of native and modified photoadducts on agarose gel electrophoresis. The DNA-arginine and peroxynitrite-modified photoadducts could have important implications in various pathophysiological and immunopathological conditions.

Language in Society, 2011

This book is an empirical study of Indian English (IndE) conducted in a corpus-based framework. T... more This book is an empirical study of Indian English (IndE) conducted in a corpus-based framework. The book is divided into six chapters. In Ch. 1, Sedlatschek discusses the sociolinguistic significance of English in India. He argues that despite the fact that English is firmly entrenched in India, there is little empirical research on the structure of IndE. Ch. 2 provides the theoretical and methodological framework of the study. Placing IndE in the Outer Circle of Kachru's model of World Englishes, Sedlatschek provides a historical account of the transplantation, expansion, and institutionalization of English in India. Given the enormous variation within IndE, Sedlatschek clarifies that his study focuses on the "educated variety of contemporary South Asian English" (27). Sedlatschek also shows that the existing studies are based on impressionistic accounts, containing a list of features that are believed to be characteristic of IndE. He argues that an advantage of a corpus study is that it allows for a qualitative analysis of language use in context. His study is based on an analysis of the Kolhapur Corpus and the International Corpus of English-India, combined with his own microcorpus. These closed corpora were supplemented with online newspapers. In Ch. 3, Sedlatschek examines the lexical features of IndE. He makes the discussion rich by including the sociolinguistic contexts within which loanwords from Indian languages tend to occur. He shows that the use of loanwords is more common in texts that deal with socio-cultural realities of India than those that deal with general issues. He further points out that many loanwords show regional variation. For example, the loanword vidhan sabha is more frequent in the Hindi-speaking region than others. In Ch. 4, Sedlatschek examines the lexico-syntactic features of IndE and demonstrates that, contrary to the impressionistic accounts, his corpus study shows that only a tiny percentage of features show variation from Standard English norms. For example, he shows that in the category of particle verbs such as throw away, verbs that show variation from Standard English norms constitute only three percent. This suggests that any claims about the uniqueness of IndE based on the verb-particle feature are misleading. On a qualitative level, however, he shows that IndE has developed innovative uses of verb-particle combinations such as stress on, discuss about, and urge for. In Ch. 5, Sedlatschek studies many morphosyntactic features of IndE, such as the use of articles, count and mass nouns, and the past perfect tense. He argues that, in

Blood, 2008

Among the patients with bone marrow hypoplasia, differentiating aplastic anemia (AA) from hypopla... more Among the patients with bone marrow hypoplasia, differentiating aplastic anemia (AA) from hypoplastic myelodysplastic syndrome (HMDS) can be a difficult and challenging task because of the considerable clinical, cytological and histological similarities between these two disorders. The distinction between AA and HMDS is important because the clinical course and management of these two entities differ. There is a higher risk of progression to acute leukemia in patients with HMDS compared with AA. Various attempts have been made in the past to differentiate these entities. Different patterns of proliferation of bone marrow cells in AA and HMDS have been reported in past using proliferating cell nuclear antigens (PCNA). S-Phase Fraction (SPF) reflects the cellular proliferation and has been proven to be a useful diagnostic and prognostic marker in various hematological malignancies and solid tumors. In the present study, we examined whether flow cytometric analysis of SPF could be used...

2009 4th International Symposium on Wireless Pervasive Computing, 2009

Abstract Due to their popularity, dense deployments of wireless local area networks (WLANs) are b... more Abstract Due to their popularity, dense deployments of wireless local area networks (WLANs) are becoming a common feature of many cities around the world. However, with only a limited number of channels available, the problem of increased interference can severely degrade the performance of WLANs if an effective channel assignment scheme is not employed. Previous studies on channel assignment in WLANs almost always assume that all access points (AP) employ the same channel assignment scheme which is clearly ...

Gastroenterology, 2013

CDC5L expression was found in the nuclei of normal murine intestinal epithelial cells. Areas of t... more CDC5L expression was found in the nuclei of normal murine intestinal epithelial cells. Areas of the colonic epithelium in AhCre + Apc fl/fl and Apc Min/+ mice which showed evidence of Wnt signalling by nuclear localisation of beta catenin showed increased nuclear expression of SFRS2 and cytoplasmic localisation of CDC5L. CDC5L knockdown in HCT116 and HT29 cells resulted in significant inhibition of cell proliferation by both SRB and clonogenic assays (p,0.05). SFRS2 knockdown also resulted in increased nuclear expression of CDC5L in these cell lines. The malignant colonic lesions that developed in Apc Min/+ Pten-/mice showed loss of nuclear beta catenin expression and reversal of the phenotype observed in Apc Min/+ mice, with nuclear CDC5L localisation once again. Conclusion Apc inactivation results in increased nuclear expression of SFRS2 in colonic epithelial cells in vivo. This coincides with translocation of CDC5L from the nucleus into the cytoplasm, which limits its ability to regulate the cell cycle and splice pre-mRNA. Acquisition of an additional mutation in Pten alters Wnt signalling further, causing reduced nuclear accumulation of beta catenin and allowing CDC5L to translocate back into the nucleus, where it possibly stabilises the tumor phenotype.

The Journal of Physical Chemistry, 1982

layered intercalation compounds are in progress and the results will be reported in the near futu... more layered intercalation compounds are in progress and the results will be reported in the near future. rate constant for OH-is 5 times larger than that for C1-, while the value of the deintercalation rate constant for OHis 3 times smaller than that for C1-. This indicates that OH-may interact strongly with the solid host lattice in the layers of the Ni-HT(C1). Similar kinetic investigations in aqueous suspensions of Acknowledgment. We thank Kyowa Chemical Co. for the supply of the synthetic hydrotalcite-like compound and thank Mr. Shigeo Miyata for his useful suggestions. Mechanism of Reduction of Bis(2-hydroxyethyl) Trisulfide by eaq-and CO,-. Spectrum and Scavenglng of RSS. Radicals

Magnetic Resonance in Medicine, 2014

Purpose-For the application of compressive sensing to parallel MRI, Poisson disk sampling (PDS) h... more Purpose-For the application of compressive sensing to parallel MRI, Poisson disk sampling (PDS) has been shown to generate superior results compared with random sampling methods. However, due to its limited flexibility to incorporate additional constraints, PDS is not readily extendible to dynamic applications. Here, we propose and validate a pseudo-random sampling technique that allows incorporating constraints specific to dynamic imaging. Methods-The proposed sampling scheme, called variable density incoherent spatiotemporal acquisition (VISTA), is based on constrained minimization of Riesz energy on a spatiotemporal grid. Data from both a digital phantom and real-time cine were used to compare VISTA with uniform interleaved sampling (UIS) and variable density random sampling (VRS). The image quality was assessed qualitatively and quantitatively.

This paper analyzes the performance of Enhanced relay-enabled Distributed Coordination Function (... more This paper analyzes the performance of Enhanced relay-enabled Distributed Coordination Function (ErDCF) for wireless ad hoc networks under transmission errors. The idea of ErDCF is to use high data rate nodes to work as relays for the low data rate nodes. ErDCF achieves higher throughput and reduces energy consumption compared to IEEE 802.11 Distributed Coordination Function (DCF) in an ideal

2007 6th International Conference on Information, Communications & Signal Processing, 2007

Abstract The popularity of wireless local area networks (WLANs) has resulted in their dense deplo... more Abstract The popularity of wireless local area networks (WLANs) has resulted in their dense deployment in many cities around the world. The increased interference among different WLANs severely degrades the throughput achievable. This problem has been further exacerbated by the limited number of frequency channels available. An improved distributed and dynamic channel assignment scheme that is simple to implement and does not depend on the knowledge of the throughput function is proposed in this work. It also allows each ...

Health Physics, 2015

A miniature electron spin resonance (ESR) probehead that includes a static field source and a mic... more A miniature electron spin resonance (ESR) probehead that includes a static field source and a microwave resonator for in vivo measurement of paramagnetic defects in tooth enamel was developed. These defects are known to be a good marker for quantifying the ionizing radiation dose absorbed in teeth. The probehead has a typical length of just 30 mm and total weight of 220 g. The patient "bites" into the probehead while the measurement procedure is being carried out. The probehead operates in pulsed mode at a frequency of ∼11.2 GHz and supplies a static magnetic field of ∼400 mT. A detailed design of the probehead is provided together with its specifications in terms of measurement volume and signal-to-noise ratio for a typical sample. A specially developed simulation program was used to predict the spatial distribution of the acquired signal under conditions of grossly inhomogeneous static and RF fields. Experimental results with irradiated incisor teeth validated the probehead's sensitivity, being able to detect signals in tooth irradiated by only 2 Gy. Subject to additional improvements and tests, this type of probehead can potentially have significant clinical applications ranging from mass triage following major nuclear events to routine occupational evaluation of ionizing radiation absorbed over long periods of time.

2011 IEEE 4th International Conference on Cloud Computing, 2011

... servers, storage, applications,) that can be rapidly provisioned and released with minimal ma... more ... servers, storage, applications,) that can be rapidly provisioned and released with minimal management effort or service provider interaction. This cloud model promotes availability and is comprised of five key characteristics, three delivery models, and four deployment models”. ...

2009 IEEE 70th Vehicular Technology Conference Fall, 2009

Abstract-This paper analyzes the performance of Enhanced relay-enabled Distributed Coordination F... more Abstract-This paper analyzes the performance of Enhanced relay-enabled Distributed Coordination Function (ErDCF) for wireless ad hoc networks under transmission errors. The idea of ErDCF is to use high data rate nodes to work as relays for the low data rate nodes. ErDCF ...

VTC Spring 2008 - IEEE Vehicular Technology Conference, 2008

Abstract Due to its popularity, dense deployments of wireless local area networks (WLANs) are bec... more Abstract Due to its popularity, dense deployments of wireless local area networks (WLANs) are becoming a common feature of many cities around the world. However, with only a limited number of channels available, the problem of increased interference can severely degrade the performance of WLANs if an effective channel assignment scheme is not employed. In an earlier work, we proposed an improved asynchronous distributed and dynamic channel assignment scheme that (1) is simple to implement,(2) does not require ...

Agronomy for Sustainable Development, 2008

Composting provides an excellent way to manage the huge volume of organic waste and convert it in... more Composting provides an excellent way to manage the huge volume of organic waste and convert it into a useful soil amendment. The effectiveness of composted organic waste can be further improved by enriching and blending it with nutrients and biologically active substances. The resulting value-added composts can be used at substantially low rates such as a few hundred kg per ha compared with conventional use of organic wastes in tons per ha. This approach could have practical significance in reducing the use of chemical fertilizer for sustainable agriculture and the environment. L-tryptophan is a precursor of the growth hormone indole acetic acid and is known to stimulate plant growth at extremely low concentrations. Here, we studied the effect of composted fruit and vegetable wastes, enriched with N at 133 g kg −1 compost, with or without L-tryptophan at 10 mg kg −1 compost, on soil and maize crops. The enriched compost was applied at 300 kg ha −1 to a sandy clay loam soil either by mixing with the top 15-cm soil layer in pots or as a band placement along the maize plants grown in the field. The compost was applied alone and in combination with 40 or 80 kg ha −1 urea N and compared with a treatment containing 160 kg N ha −1 , a full dose of N fertilizer alone, while P and K fertilizers were applied in all the treatments. Our results show that application of the enriched compost to soil increased aggregate stability by up to 24.8% and water retention by up to 43.1% compared with untreated control. A gradual increase in the concentration of indole acetic acid in compost, ranging from 1.02 to 3.34 mg kg −1 , was observed when compost was treated with its precursor L-tryptophan. The results of pot and field experiments revealed that compost enriched with N and L-tryptophan in the presence of 80 kg N fertilizer significantly increased cob and grain yields, by up to 19.8 and 21.4%, respectively, compared with a full dose of N fertilizer. These findings suggest that enrichment of composted organic wastes with N and L-tryptophan can change them into a value-added organic product that could be used as a soil amendment at rates as low as 300 kg ha −1 to increase crop production on a sustainable basis.

Materials Letters, 2015

Fire-retarding materials are essential in order to fulfill the various requirements in our daily ... more Fire-retarding materials are essential in order to fulfill the various requirements in our daily life. Here we present the macro-porous self-setting aluminum trihydroxide (ATH) foams which were fabricated by a direct-foaming technique. Sodium dodecyl sulfate (SDS) was used as a surfactant. The microstructure of the foam was set immediately by the addition of ordinary Portland cement. The ATH foams obtained by this technique have cell size in the range of 50 to 180 mm and porosity in the range of 88 to 92%. Finally, the fire retarding capability of self-setting ATH foam was characterized by TGA/DSC.

Indian Journal of Clinical Biochemistry, 2013

Reactive oxygen species, as singlet oxygen (1 O 2), is continuously being generated by aerobic or... more Reactive oxygen species, as singlet oxygen (1 O 2), is continuously being generated by aerobic organisms, and react actively with biomolecules. At excessive amounts, 1 O 2 induces oxidative stress and shows carcinogenic and toxic effects due to oxidation of lipids, proteins and nucleic acids. In our study, immunoglobulin G (IgG) was modified by 1 O 2 generated by the ultraviolet (UV) irradiation of methylene blue. The modified IgG was characterized by UV spectroscopy, carbonyl content determination, thermal denaturation and electrophoretic study. Oxidation induced by modification of IgG by 1 O 2 also analyzed by scavenging studies. It was found that ultraviolet absorption spectra of modified IgG shows marked hyperchromicity. The carbonyl content was found to be high in modified IgG as compared to native IgG which confirms its oxidation. Thermal denaturation of modified protein sample shows decrease in Tm value by 3°C and less intensity banding pattern on polyacrylamide gel electrophoresis. The quenching effect of sodium azide provides clue for modification of IgG by methylene blue, as it is known 1 O 2 scavenger. Hence, the IgG modified with 1 O 2 may be one of the etiological pathogenic factors for rheumatoid arthritis and diabetes.

Communications in Computer and Information Science, 2010

Quality is an important consideration in the development of today's large complex software system... more Quality is an important consideration in the development of today's large complex software systems. Software architecture and quality play a vital role in the success or failure of any software system. Similarly to maintain the qualities of a software system during development and to adapt the quality attributes as the software requirements changes, software architecture is necessary. This paper discusses software quality attributes and the support provided by software architecture to achieve the desired quality. A novel Software Architecture Reuse and Evaluation framework is proposed on the basis of existing software architecture evaluation methods with respect to quality requirements. A case study is used for experimental validation of the ISARE. The results show that ISARE ensures the required level of quality requirements in the software architecture and automatable.

VTC Spring 2008 - IEEE Vehicular Technology Conference, 2008

Unlike the terrestrial wireless networks that utilize the radio channel, underwater networks use ... more Unlike the terrestrial wireless networks that utilize the radio channel, underwater networks use the acoustic channel, which poses research challenges in the medium access control (MAC) protocol design due to its low bandwidth and high propagation delay characteristics. Since most of the MAC protocols for wireless terrestrial networks have been designed with negligible propagation delay in mind, they generally perform poorly when applied directly in underwater acoustic networks, especially for the case of handshaking-based protocols. In this paper, we propose a MACA-based MAC protocol with packet train to multiple neighbors (MACA-MN). It improves the channel utilization by forming a train of packets destined for multiple neighbors during each round of handshake, which greatly reduces the relative proportion of time wasted due to the propagation delays of control packets. This approach also reduces the hidden terminal problem. Our simulations show that the MACA-MN is able to achieve much higher throughput than the MACA protocol.

Toxicology Mechanisms and Methods, 2008

ABSTRACT Peroxynitrite is a reactive oxidant produced from nitric oxide ((.)NO) and superoxide an... more ABSTRACT Peroxynitrite is a reactive oxidant produced from nitric oxide ((.)NO) and superoxide anion (O(2)(.-)). It is produced by the body in response to environmental toxins, stress, ultraviolet light, ischemia/reperfusion, inflammation, etc. In vivo, peroxynitrite is formed in macrophages, endothelial cells, platelets, leukocytes, and neurons. It reacts with a variety of biomolecules including proteins, lipids, and DNA. We have investigated the photochemical addition of lysine to native DNA in view of its potential importance in the photo-cross-linking of histones to DNA in chromatin. Lysine-and arginine-rich histone H1 in nucleosome on modification by physical, chemical, or environmental agents forms histone-DNA adducts. We have characterized the photoadducts by absorption, fluorescence, and chromatographic methods. The UV absorption spectra of the DNA-lysine photoadduct showed hyperchromism, indicating structural distortions in DNA either due to single-strand breaks or opening of the double helix at the site of lysine conjugation. On peroxynitrite treatment, the melting temperature (T(m)) of the DNA-lysine adduct increased by 15 degrees C compared to the native DNA-lysine adduct. A decrease in the fluorescence intensity of the DNA-lysine photoadduct with respect to the modified adduct was observed. The gel filtration profile of the peroxynitrite-modified adduct was also found to be different from that of the native DNA and DNA-lysine photoadduct. Hence, the peroxynitrite-modified photoadduct may have important implications in toxicology, mutagenesis, and carcinogenesis.

Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology, 2009

The oculocerebrorenal syndrome of Lowe (OCRL) is a rare X-linked recessive disorder, chiefly char... more The oculocerebrorenal syndrome of Lowe (OCRL) is a rare X-linked recessive disorder, chiefly characterized by ocular involvement, mental retardation, and kidney disease. A literature review is provided, detailing the diversity of oral anomalies associated with the OCRL syndrome. Reported abnormalities include delayed tooth eruption, odontogenic cyst formation, and constricted dental arches. In addition, we present an unusual case of an 18-year-old male affected with the OCRL syndrome and fetal alcohol syndrome. The oral radiographic examination was significant for multiple impacted permanent teeth, many with pericoronal radiolucencies, and an underdeveloped mandible.

Nucleosides, Nucleotides and Nucleic Acids, 2012

The aim of the study is the biochemical characterization of human DNA modified with arginine and ... more The aim of the study is the biochemical characterization of human DNA modified with arginine and peroxynitrite. In the present study, DNA was isolated from human blood cells and its adduct was formed with one of the amino acid, arginine. The DNA-arginine adduct was then modified with peroxynitrite, a reactive nitrogen species. The modified DNA adduct was characterized by ultraviolet (UV) absorption spectroscopy, thermal melting profile, and electrophoresis studies. UV spectroscopic analysis of the photoadduct showed hyperchromicity, indicating the formation of single-strand breaks and photomodification. Thermal denaturation studies of DNA-arginine adduct and peroxynitrite-modified adduct showed a decrease in the temperature (T(m)) value by 4.5°C and an increase in the T(m) of 8°C, respectively. Peroxynitrite modification is evident by an increase in the T(m) value and a change in the migration pattern of native and modified photoadducts on agarose gel electrophoresis. The DNA-arginine and peroxynitrite-modified photoadducts could have important implications in various pathophysiological and immunopathological conditions.

Language in Society, 2011

This book is an empirical study of Indian English (IndE) conducted in a corpus-based framework. T... more This book is an empirical study of Indian English (IndE) conducted in a corpus-based framework. The book is divided into six chapters. In Ch. 1, Sedlatschek discusses the sociolinguistic significance of English in India. He argues that despite the fact that English is firmly entrenched in India, there is little empirical research on the structure of IndE. Ch. 2 provides the theoretical and methodological framework of the study. Placing IndE in the Outer Circle of Kachru's model of World Englishes, Sedlatschek provides a historical account of the transplantation, expansion, and institutionalization of English in India. Given the enormous variation within IndE, Sedlatschek clarifies that his study focuses on the "educated variety of contemporary South Asian English" (27). Sedlatschek also shows that the existing studies are based on impressionistic accounts, containing a list of features that are believed to be characteristic of IndE. He argues that an advantage of a corpus study is that it allows for a qualitative analysis of language use in context. His study is based on an analysis of the Kolhapur Corpus and the International Corpus of English-India, combined with his own microcorpus. These closed corpora were supplemented with online newspapers. In Ch. 3, Sedlatschek examines the lexical features of IndE. He makes the discussion rich by including the sociolinguistic contexts within which loanwords from Indian languages tend to occur. He shows that the use of loanwords is more common in texts that deal with socio-cultural realities of India than those that deal with general issues. He further points out that many loanwords show regional variation. For example, the loanword vidhan sabha is more frequent in the Hindi-speaking region than others. In Ch. 4, Sedlatschek examines the lexico-syntactic features of IndE and demonstrates that, contrary to the impressionistic accounts, his corpus study shows that only a tiny percentage of features show variation from Standard English norms. For example, he shows that in the category of particle verbs such as throw away, verbs that show variation from Standard English norms constitute only three percent. This suggests that any claims about the uniqueness of IndE based on the verb-particle feature are misleading. On a qualitative level, however, he shows that IndE has developed innovative uses of verb-particle combinations such as stress on, discuss about, and urge for. In Ch. 5, Sedlatschek studies many morphosyntactic features of IndE, such as the use of articles, count and mass nouns, and the past perfect tense. He argues that, in