Showing papers by "Rajesh Kumar published in 2003"

A divisive information theoretic feature clustering algorithm for text classification

Abstract: High dimensionality of text can be a deterrent in applying complex learners such as Support Vector Machines to the task of text classification. Feature clustering is a powerful alternative to feature selection for reducing the dimensionality of text data. In this paper we propose a new information-theoretic divisive algorithm for feature/word clustering and apply it to text classification. Existing techniques for such "distributional clustering" of words are agglomerative in nature and result in (i) sub-optimal word clusters and (ii) high computational cost. In order to explicitly capture the optimality of word clusters in an information theoretic framework, we first derive a global criterion for feature clustering. We then present a fast, divisive algorithm that monotonically decreases this objective function value. We show that our algorithm minimizes the "within-cluster Jensen-Shannon divergence" while simultaneously maximizing the "between-cluster Jensen-Shannon divergence". In comparison to the previously proposed agglomerative strategies our divisive algorithm is much faster and achieves comparable or higher classification accuracies. We further show that feature clustering is an effective technique for building smaller class models in hierarchical classification. We present detailed experimental results using Naive Bayes and Support Vector Machines on the 20Newsgroups data set and a 3-level hierarchy of HTML documents collected from the Open Directory project (www.dmoz.org).

Polymorphisms in DNA repair and metabolic genes in bladder cancer

Abstract: We investigated the association of urinary bladder cancer with genetic polymorphisms in the xeroderma pigmentosum complementation group C (XPC), group D (XPD) and group G (XPG), X-ray repair cross-complementing group 1 (XRCC1) and group 3 (XRCC3), Nijmegen breakage syndrome 1 (NBS1), cyclin D1, methylene-tetrahydrofolate reductase (MTHFR), NAD(P)H dehydrogenase quinone 1 (NQO1), H-ras and glutathione S-transferase theta 1 (GSTT1) genes. Bladder cancer patients from the different hospitals in Stockholm County Council area and matching controls were genotyped for different polymorphisms. The frequency of the variant allele for A/C polymorphism in exon 15 of the XPC gene was significantly higher in the bladder cancer cases than in the controls (OR 1.49, 95% CI 1.16-- 1.92, Pa 0.001). The variant allele homozygote genotype for the T/C polymorphism in exon 1 of the H-ras gene was associated with a decreased risk for bladder cancer (OR 0.12, 95% CI 0.02-- 0.67, Pa 0.006). The variant allele genotypes for the single nucleotide polymorphisms (SNPs) in DNA repair genes, XPG and NBS1, showed a marginal association with the occurrence of bladder cancer (OR 0.38, 95% CI 0.15-- 0.94, Pa 0.03 and OR 1.64, 95% CI 0.92-- 2.90, Pa 0.09, respectively). We also report a positive correlation between the null homozygote of GSTT1 with the risk of bladder cancer (OR 2.54, 95% CI 1.32-- 4.98, Pa 0.003). For other polymorphisms included in this study, NBS1 Glu185Gln, XPD Lys751Gln, XPG Asp1104His, XRCC1 Arg399Gln, XRCC3 Thr241Met, cyclin D1 Pro242Pro, MTHFR Ala222Val and Glu429Ala, NQO1 Arg139Trp and Pro187Ser, no significant differences for genotype distributions and allele frequencies between the bladder cancer cases and the controls were observed in the present study.

Morbidity profile and its relationship with disability and psychological distress among elderly people in Northern India

Abstract: Background Morbidity among elderly people has an important influence on their physical functioning and psychological well-being. Evaluation of the morbidity profile and its determinants, which have implications for elderly people, are not available. The objective of this study is to assess morbidity, co-morbidity, and patterns of treatment seeking, and to determine relationship of morbidity with disability, psychological distress, and socio-demographic variables among the elderly population in northern India. Methods A cross-sectional survey of 200 subjects over 60 years old (100 each from the urban population of Chandigarh City and the rural population of Haryana State of India) was carried out using a cluster sampling technique. The study period was July 1999‐April 2000. Various socio-demographic characteristics were recorded at baseline. A clinical diagnosis was made by a physician based on reported illness, clinical examination, and cross-checking of medical records and medications held by the subjects. Psychological distress and disability was assessed using the PGI-Health Questionnaire-N-1 and the Rapid Disability Rating Scale-2, respectively. ANOVA, Kruskal‐Wallis H test, correlation coefficient, and multivariate analysis were used to assess the relationship and association of morbidity with other variables. Results Of the total sample, 88.9% reported illness based on their perception, and of these 43.5% were seeking treatment and actually taking medicines, and 42.5% were diagnosed as having 4‐6 morbidities. The mean number of morbidities among elderly people was 6.1 (SD 2.9). A total of 87.5% had minimal to severe disabilities and 66% of elderly people were distressed physically, psychologically, or both. The most prevalent morbidity was anaemia, followed by dental problems, hypertension, chronic obstructive airway disease (COAD), cataract, and osteoarthritis. Morbidities like asthma, COAD, hypertension, osteoarthritis, gastrointestinal disorders, anaemia, and eye and neurological problems were significantly associated with disability and distress. Higher number of morbidities was associated with greater disability and distress. In univariate analysis, socio-demographic variables like age, locality, caste, education, occupation, and income were important determinants of morbidity. Multivariate analysis was undertaken to find out the independent relationship of socio-demographic variables with morbidity. Morbidity was significantly associated with age (b value 0.06, 95% CI: 0.01, 0.12), sex (b value 1.03, 95% CI: 0.02, 2.05), and occupation (b value 0.20, 95% CI: 0.07, 0.33). Conclusions A high mean number of morbidities (6.1, SD 2.9) was observed. Elderly subjects with higher morbidity had increasing disability and distress. Age, sex, and occupation were important determinants of morbidity. Assessment of the morbidity profile and its determinants will help in the application of interventions, both

Secreted frizzled-related protein 4 is a potent tumor-derived phosphaturic agent

Abstract: Tumors associated with osteomalacia elaborate the novel factor(s), phosphatonin(s), which causes phosphaturia and hypophosphatemia by cAMP-independent pathways. We show that secreted frizzled-related protein-4 (sFRP-4), a protein highly expressed in such tumors, is a circulating phosphaturic factor that antagonizes renal Wnt-signaling. In cultured opossum renal epithelial cells, sFRP-4 specifically inhibited sodium-dependent phosphate transport. Infusions of sFRP-4 in normal rats over 2 hours specifically increased renal fractional excretion of inorganic phosphate (FEPi) from 14% ± 2% to 34% ± 5% (mean ± SEM, P < 0.01). Urinary cAMP and calcium excretion were unchanged. In thyroparathyroidectomized rats, sFRP-4 increased FEPi from 0.7% ± 0.2% to 3.8% ± 1.2% (P < 0.05), demonstrating that sFRP-4 inhibits renal inorganic phosphate reabsorption by PTH-independent mechanisms. Administration of sFRP-4 to intact rats over 8 hours increased FEPi, decreased serum phosphate (1.95 ± 0.1 to 1.53 ± 0.09 mmol/l, P < 0.05) but did not alter serum 1α, 25-dihydroxyvitamin D, renal 25-hydroxyvitamin D 1α-hydroxylase cytochrome P450, and sodium-phosphate cotransporter mRNA concentrations. Infusion of sFRP-4 antagonizes Wnt action as demonstrated by reduced renal β-catenin and increased phosphorylated β-catenin concentrations. The sFRP-4 is detectable in normal human serum and in the serum of a patient with tumor-induced osteomalacia. Thus, sFRP-4 displays phosphatonin-like properties, because it is a circulating protein that promotes phosphaturia and hypophosphatemia and blunts compensatory increases in 1α, 25-dihydroxyvitamin D.

Vitamin d and its analogs as regulators of immune activation and antigen presentation

Abstract: It has been a little more than 20 years since the first appreciation that the biologically active hormonal form of the secosteroid vitamin D-classically categorized as a regulator of calcium/phosphorous metabolism and bone mineralization-can exert effects on cells of the immune system. Since then a substantial literature has accumulated to suggest that these effects are exerted on multiple immune cell types, are predominantly suppressive at pharmacologic levels, and are potent enough to have true therapeutic potential in the management or prevention of immune-mediated diseases. Less clear at present, however, are the physiological roles played by the vitamin D endocrine system in the regulation of normal and abnormal immune responses. In this review, an appraisal of the current understanding of vitamin D-mediated immune regulation is presented that emphasizes progress towards its clinical application as well as the manner in which emerging models of normal immune function may facilitate a more complete understanding of its physiologic significance.

Genetic polymorphisms in DNA repair genes and possible links with DNA repair rates, chromosomal aberrations and single-strand breaks in DNA

Abstract: We analysed the associations between genetic polymorphisms in genes coding for DNA repair enzymes XPD (exon 23 A --> C, K751Q), XPG (exon 15 G --> C, D1104H), XPC (exon 15 A --> C, K939Q), XRCC1 (exon 10 G --> A, R399Q) and XRCC3 (exon 7 C --> T, T241 M) and the levels of chromosomal aberrations (CAs) and single-strand breaks (SSBs) in peripheral lymphocytes in a central European population. We also measured the irradiation-specific DNA repair rates and the repair rates of 8-oxoguanines in these individuals. An elevated frequency of CAs was observed in individuals with the XPD exon 23 A allele (AA and AC) genotypes (F = 3.6, P = 0.028, ANOVA). In multifactorial analysis of variance, the XPD exon 23 polymorphism appeared as a major factor influencing CAs (F = 4.2, P = 0.017). SSBs in DNA, on the other hand, were modulated by XPD (F = 4.3, P = 0.023), XPG (F = 4.3, P = 0.024) and XRCC1 genotypes (F = 3.0, P = 0.064). Irradiation-specific DNA repair rates (reflecting mainly base excision repair activity) were affected by XRCC1 (F = 5.9, P = 0.010) and XPC polymorphisms (F = 4.2, P = 0.046, MANOVA). Our results from this study suggest that markers of genotoxicity are associated with polymorphisms in genes encoding DNA repair enzymes.

BRAF Mutations in Metastatic Melanoma: A Possible Association with Clinical Outcome

Abstract: Purpose: The RAS-RAF-mitogen-activated protein kinase pathways mediate the cellular response to growth signals. In melanocytes, BRAF is involved in cAMP-dependent growth signals. Recently, activating mutations in the BRAF gene, were reported in a large proportion of melanomas. We have studied mutations in the BRAF gene and their association with clinical parameters. Experimental Design: We analyzed exons 1, 11, and 15 of the BRAF gene and exons 1 and 2 of the N-ras gene for mutations in 38 metastatic melanomas by PCR-single-strand conformation polymorphism and direct sequencing. Kaplan-Meier survival and multivariate analyses were used to correlate mutations with various clinical parameters. Results: Mutations in exon 15 of the BRAF gene were detected in 26 (68%) melanomas. In 25 cases, mutation involved the “hot spot” codon 600 2 of the BRAF gene. Three melanomas without a BRAF mutation carried amino acid substituting base changes at codon 61 of the N-ras gene. In a multivariate proportional hazard (Cox) model, BRAF mutation, along with the stage of metastatic melanomas, showed a statistically significant hazard ratio of 2.16 (95% confidence interval 1.02–4.59; χ 2 for the model 6.94, degrees of freedom 2, P = 0.03) for diminished duration of response to the treatment. In a Kaplan-Meier survival model, cases with BRAF mutation showed longer disease-free survival (median of 12 months) than cases without mutation (median of 5 months), although this association was not statistically significant (Log-rank test P = 0.13). Conclusions: Our results, besides confirming the high frequency of BRAF mutations in metastatic melanomas, also underline the potential importance of these mutations in disease outcome.

Detecting homozygous deletions in the CDKN2A(p16(INK4a))/ARF(p14(ARF)) gene in urinary bladder cancer using real-time quantitative PCR.

Abstract: Purpose: 9p21 is a major target in the pathogenesis of human urinary bladder cancer. The locus harbors the CDKN2A/ARF tumor suppressor gene, which encodes two cell cycle regulatory proteins cyclin dependent kinase 2A (p16 INK4a ) and alternate reading frame (p14 ARF ). We have designed a real-time quantitative PCR (QPCR) application to study homozygous deletion (HD) of CDKN2A/ARF in 186 urinary bladder cancer patients. Experimental Design: Real-time QPCR, based on simultaneous amplification of ARF and a reference gene, GAPDH , was developed and evaluated in three melanoma cell lines with HDs at the CDKN2A/ARF locus (IGR-1, SK-MEL-5, and WM-266-4). In addition, loss of heterozygosity was analyzed at the D9S942, D9S1748 , and D12S99 markers. Mutation analysis of the CDKN2A/ARF gene was performed using single-strand conformational polymorphism and sequencing. Results from the present investigation were combined with previous p53 analysis of the same urinary bladder neoplasms. Results: Real-time QPCR analysis showed 26 (14%) HDs, 22 (12%) hemizygous deletions, and 3 (2%) multiple duplications. Loss of heterozygosity was determined in 30 (22%) cases at the D9S942 locus, which is located between E1α and E1β of the CDKN2A/ARF gene. No association was established between occurrence of genetic aberrations at 9p21 and tumor stage or grade, supporting previous suggestions that CDKN2A/ARF inactivation is an early event in bladder carcinogenesis. Conclusions: We have established a fast and efficient method for detection of HDs. Our data support the notion that inactivation, including HDs, of CDKN2A/ARF is an early event in transitional cell carcinoma. We observed separate and specific targeting of the CDKN2A and ARF genes, respectively, and that simultaneous inactivation of ARF and p53 occurs.

CuO-doped SnO2 thin films as hydrogen sulfide gas sensor

Abstract: CuO-loaded SnO2 element was earlier identified as a highly sensitive and selective H2S gas sensor. A number of techniques have been used by different authors for preparing thick and thin films of SnO2 doped with CuO, which among various metal oxides has outstanding promoter action for the sensitive detection of H2S by SnO2. Here we report the growth and characterization of CuO-doped SnO2 thin films by a thermal evaporation technique. These thin films show an extremely high sensitivity of ∼106 to few parts per million levels of H2S gas in air. The gas sensor is characterized at four operating temperatures and its long-term stability in response to H2S gas is tested over a period of 3 years.

Single nucleotide polymorphisms in the XPG gene: determination of role in DNA repair and breast cancer risk.

Abstract: In this study we determined the effect of single nucleotide polymorphisms in the XPG gene on DNA repair and breast cancer susceptibility. Ninety individuals, with previously studied DNA repair rate at 24 hr of 2 types of UV-specific cyclobutane pyrimidines dimers (CPDs) in skin were genotyped for XPG polymorphism at codon 1104 (exon 15 G>C; Asp > His). The repair rate of TT=C dimer was similar in both wild-type GG homozygotes and GC heterozygotes, whereas, for TT=T, dimer repair was non-significantly (Student's t-test, p = 0.34) lower in GC heterozygotes than wild-type GG homozygotes. Genotyping of 220 breast cancer cases and 308 controls for the same single nucleotide polymorphism in exon 15 of the XPG gene exhibited marginally significant increased frequency of the variant allele (chi(2) 3.84, p = 0.05; OR 1.33, 95% CI 1.0-1.8) in cases (C-allele 0.29) compared to controls (C-allele 0.24). Combined heterozygote and variant homozygote genotype frequency was also higher in cases than controls (chi(2) 4.79, p = 0.03; OR 1.50, 95%CI 1.04-2.16).

Is reversible posterior leukoencephalopathy with severe hypertension completely reversible in all patients

Abstract: Leukoencephalopathy with severe hypertension is a recently described entity in nephrology, with only a few case reports to date in children. We prospectively studied 18 children with severe hypertension to evaluate the clinical features, severity, reversibility, and prognosis. All were subjected to clinical and biochemical tests, magnetic resonance imaging (MRI), and magnetic resonance angiography (MRA). Headache was reported in 16 children, 13 had confusion and drowsiness, 12 had nausea and vomiting, and 9 had visual disturbances, seizure, and dyspnea. Only 2 had focal neurological deficit (1 with right facial palsy and another with right lateral rectus palsy). Of these 18 children, 14 patients had hypertensive retinopathy and 4 had normal fundus. MRI revealed leukoencephalopathic changes in 16 of 18 patients. These changes were bilateral occipito-parietal in 9 patients, diffuse white/gray matter lesion in 2, brain stem hyperintensity in 2, and hemorrhagic lesion in 3. On MRA, 11 of 18 patients had attenuation of cerebral arteries of different degree. On follow-up, MRI findings resolved in all except 3 patients and all patients had normal MRA, except for 1 with persistent minimal attenuation and another with spasm in all vessels. We conclude that leukoencephalopathy with severe hypertension is reversible both clinically and radiologically in the majority of children after the control of hypertension. However, a few patients may have residual damage and may need psychometric analysis and follow-up for neurodevelopmental sequelae.

Activating BRAF and N-Ras mutations in sporadic primary melanomas: an inverse association with allelic loss on chromosome 9.

Abstract: We searched and report mutations in the BRAF and N-ras genes in 22 out of 35 (63 percent) primary sporadic melanomas. In three melanomas, mutations were concomitantly present in both genes. In all, 10 out of 12 mutations in the BRAF gene involved the ‘hot spot’ codon 600 (In all communications on mutations in the BRAF gene, the nucleotide and codon numbers have been based on the NCBI gene bank nucleotide sequence NM_004333. However, according to NCBI gene bank sequence with accession number NT_007914, there is a discrepancy of one codon (three nucleotides) in exon 1 in the sequence with accession number NM_004333. The sequence analysis of exon 1 of the BRAF gene in our laboratory has shown that the sequence derived from NT_007914 is correct (Kumar et al., 2003). Due to the correctness of the latter, sequence numbering of codons and nucleotides after exon 1 are changed by +1 and +3, respectively.), one tandem CT1789-90TC base change represented a novel mutation and another mutation caused a G466R amino-acid change within the glycine-rich loop in the kinase domain. Mutations in the N-ras gene in 11 melanomas were at codon 61 whereas two melanomas carried mutations in codon 12 including a tandem mutation GG>AA. We observed an inverse association between BRAF/N-ras mutations and the frequency of loss of heterozygosity (LOH) on chromosome 9 at 10 different loci. Melanomas with BRAF/N-ras mutations showed a statistically significant decreased frequency of LOH on chromosome 9 compared with cases without mutations (mean fractional allelic loss (FAL)=0.29±0.23 vs 0.72±0.33; t-test, P=0.0001). Difference in the FAL value between tumours with and without BRAF/N-ras mutations on 33 loci on five other chromosomes was not statistically significant (mean FAL 0.17±0.19 vs 0.25±0.22; t-test, P=0.24). Melanoma cases with BRAF/N-ras mutations were also associated with lower age at diagnosis than cases without mutations (mean age 80.38±7.24 vs 65.77±19.79 years; t-test, P=0.02). Our data suggest that the occurrence of BRAF/N-ras mutations compensate the requirement for the allelic loss at chromosome 9, which is one of the key events in melanoma.

Cluster decay of hot 56 Ni * formed in the 32 S+ 24 Mg reaction

Abstract: The decay of ${}^{56}{\mathrm{Ni}}^{*},$ formed in ${}^{32}\mathrm{S}{+}^{24}\mathrm{Mg}$ reaction at the incident energies ${E}_{\mathrm{c}.\mathrm{m}.}=51.6$ and 60.5 MeV (where c.m. is the center of mass), is calculated as a cluster decay process within the preformed cluster-decay model of Gupta et al. [Phys. Rev. C 65, 024601 (2002)] reformulated for hot compound systems. Interestingly enough, the cluster decay process is shown to contain the complete structure of both the measured fragment cross sections and total kinetic energies (TKEs). The observed deformed shapes of the exit channel fragments are simulated by introducing the neck-length parameter at the scission configuration, which nearly coincides with the ${}^{56}\mathrm{Ni}$ saddle configuration. This is the only parameter of the model, which, though, is also defined in terms of the binding energy of the hot compound system and the ground-state binding energies of the various emitted fragments. For the temperature effects included in shell corrections only, the normalized $\ensuremath{\alpha}$-nucleus s-wave cross sections calculated for nuclear shapes with outgoing fragments separated within nuclear proximity limit (here $\ensuremath{\sim}0.3\mathrm{fm})$ can be compared with the experimental data, and the TKEs are found to be in reasonably good agreement with experiments for the angular momentum effects added in the sticking limit for the moment of inertia. The incident energy effects are also shown in predicting different separation distances and angular momentum values for the best fit. Also, some light particle production (other than the evaporation residue, not treated here) is predicted at these energies and, interestingly, ${}^{4}\mathrm{He},$ which belongs to evaporation residue, is found missing as a dynamical cluster-decay fragment. Similar results are obtained for temperature effects included in all the terms of the potential energy. The non-$\ensuremath{\alpha}$ fragments are now equally important, and hence present a more realistic situation with respect to experiments.

Preliminary experiments in robot/human cooperative microinjection

Abstract: This paper reports preliminary experiments with a cooperative robot system to augment single cell manipulation tasks. The JHU "Steady-Hand" robot configuration for cell manipulation is reported. Stable force control laws for the "Steady Hand" are revisited. Preliminary experiments validating stable insertion of a micropipette in a mouse embryo are detailed along with formulation of vision based tracking and augmentation. These preliminary experiments demonstrate promise of cooperative augmentation in single cell manipulation tasks.

Simple Biomanipulation Tasks with “Steady Hand” Cooperative Manipulator

Abstract: This paper reports preliminary experiments in the development of our Augmented Micromanipulation System using the JHU “Steady Hand” cooperative robot system to augment single cell manipulation tasks. The need for robotic augmentation of biomanipulatuon tasks is discussed. The JHU “Steady-Hand” robot configuration for cell manipulation is reported. Augmentation strategies for stable cooperative insertion of a micropipette in a mouse embryo are developed and preliminary experiments validating these strategies are presented. These preliminary experiments demonstrate promise of cooperative robotic augmentation in single cell manipulation tasks.

Intent-driven functional verification of digital designs

Abstract: A method and apparatus are provided that facilitate analysis of the intended flow of logical signals between key points in a design. According to one aspect of the present invention, hardware design defects can be detected using a novel Intent-Driven Verification process. First, a representation of a hardware design and information regarding the intended flow of logical signals among variables in the representation are received. Then, the existence of potential errors in the hardware design may be inferred based upon the information regarding the intended flow of logical signals by (1) translating the information regarding the intended flow of logical signals into a comprehensive set of checks that must hold true in order for the hardware design to operate in accordance with the intended flow of logical signals, and (2) determining if any of the checks can be violated during operation of circuitry represented by the hardware design.

Clinical course of bladder neoplasms and single nucleotide polymorphisms in the CDKN2A gene.

Abstract: Point mutations and single nucleotide polymorphisms (SNPs) in the CDKN2A gene in bladder cancer patients have been resolved only to a limited extent. The exact frequency of mutations remains uncertain and reports on SNPs are lacking. In this population-based study we investigated mutations and polymorphisms in the CDKN2A gene in bladder cancer patients from all hospitals within the Stockholm County. Mutations were determined in 4 exons of the CDKN2A gene in tumor-tissues from 172 bladder cancer patients and 2 single nucleotide polymorphisms in the 3′ UTR of the CDKN2A gene were studied in 309 cases. Missense mutations were identified in only 4 of 172 (2.3%) cases, including 1 in the germ-line. Frequencies of the 500 CG and 540 CT polymorphisms in the 3′ UTR of the CDKN2A in bladder cancer cases were not statistically significantly different compared to an ethnically matched control population. The tumor-specific survival was significantly shorter in patients with either the 500 CG or 540 CT polymorphism than those with wild-type CDKN2A gene (P = 0.02). Our results corroborate the earlier findings that single base mutation is not the prime mode of inactivation of the CDKN2A gene in bladder cancer. Further, the results indicate, a role for the 3′ UTR polymorphisms in the CDKN2A gene in tumor invasiveness. © 2002 Wiley-Liss, Inc.

Cuo–sno2 element as hydrogen sulfide gas sensor prepared by a sequential electron beam evaporation technique

Abstract: CuO–SnO2 thin film elements were prepared by sequential evaporation of Sn and Cu metals in high vacuum conditions by an electron beam evaporation technique and subsequent oxidation of the metallic bilayer under flowing oxygen conditions. The electrical properties of the thin film element were studied by a two probe method in the temperature range 110–220°C. On exposing the CuO–SnO2 thin films to a H2S–air mixture, it is observed that the resistance decreases by several thousand times. The H2S sensitivity of the thin film element was measured at three sensor operating temperatures. While the sensitivity decreased with an increase in temperature, both the response and recovery times improved with increasing temperature. The sensor element was selective to H2S gas and did not show any sensitivity to hydrogen and ethanol. The extraordinarily high sensitivity to H2S gas is attributed to the outstanding promoter action of CuO along with the unique porous structure of the thin film element as revealed by scanning electron microscopy studies.

Soil Organic Carbon Store in Different Forests of India

Abstract: Global warming and emission of CO 2 are of world wide concern because these are creating environmental imbalance and are a long term threat to the well being of all life on earth. Soil is a major sink of carbon. 9815.95 million tonnes of Soil Organic Carbon (SOC) store was estimated in total forest soils (as per 1994 forest stands) under 19 species spread over 27 States and Union territories in India. Spruce forest soil has maximum SOC store (386.0 t/ha) while Khair has minimum (51.93 t/ha). In India , miscellaneous forests are spread over an area of 40.7316 million ha , and their soils have maximum SOC store (6469.80 million tonnes) while in Hollong forest with an area of 0.0068 million ha , soils have the least SOC store (0.82 million million tonnes). Among the Indian States , Arunachal Pradesh has maximum SOC store (1702.08 million tonnes) while Dadra&Nagar Haveli has minimum (2.42 million tonnes) SOC store. Arunachal Pradesh ranks first in India having 248.11 t/ha SOC store in the soils of the State. Soil conservation practices should be strengthened to conserve these natural resources so that carbon store may not deplete especially from hilly terrain.

Magnetization Transfer MR Imaging in Patients with Posttraumatic Epilepsy

Abstract: BACKGROUND AND PURPOSE: Intractable epilepsy is a well-recognized complication following head trauma, and many factors have been implicated in its pathogenesis. This study was performed to determine the severity of tissue damage after severe head injury as assessed with magnetization transfer (MT) MR imaging and the relationship of this damage with seizure intractability. METHODS: Forty-four patients, 13 without seizures (disease controls) and 31 with seizures, underwent T1-weighted MT MR imaging 1–10 years after head trauma. Phase-corrected gradient-echo (GRE) imaging was also performed in all patients to look for the presence of hemosiderin. All patients were evaluated for the presence of an MT abnormality beyond an abnormality seen on T2-weighted images, an MT abnormality within a T2 abnormality, and hemosiderin deposition. RESULTS: Patients with an MT abnormality beyond a T2 abnormality had a significantly higher intractability of seizures compared with those with an MT abnormality within a T2 abnormality ( P CONCLUSIONS: T1-weighted MT imaging may be of value in predicting the intractability of the seizure in delayed posttraumatic epilepsy.

Plane strain deformation of an orthotropic elastic medium using an eigenvalue approach

Abstract: The analytic expressions for the displacements and stresses at any point of an infinite orthotropic elastic medium as a result of an inclined line load have been obtained. This plane strain problem has been solved by using eigenvalue approach and the use of matrix notation avoids unwieldy mathematical expressions. The technique developed in the present paper is simple, straightforward and convenient for numerical computation. The variations of the displacements and stresses with the horizontal distance have been shown graphically.

Gluteal abscess: a manifestation of Pott's spine.

Abstract: A 3-year-old girl presented with features suggestive of compression of cauda equina. In addition, she had soft, fluctuant gluteal swelling, which on aspiration yielded pus, positive for acid-fast bacilli on staining and culture. She showed significant clinicoradiological improvement following aspiration of pus and antitubercular treatment. Rare manifestations of cold abscess in the spine are discussed.

Reflection/refraction of sh-waves at a corrugated interface between two different anisotropic and vertically heterogeneous elastic solid half-spaces

Abstract: We investigate the reflection and transmission of SH-waves at a corrugated interface between two different anisotropic, heterogeneous elastic solid half-spaces. Both the media are assumed to be transversely isotropic and vertically heterogeneous. Rayleigh's method is followed and expressions for the reflection and transmission coefficients are obtained in closed form for the first-order approximation of the corrugation. It is found that these coefficients depend on corrugation and are affected by the anisotropy and heterogeneity of the media. Numerical computations for a particular model have been performed.

Pharmacokinetics of omeprazole in patients with liver cirrhosis and extrahepatic portal venous obstruction.

Abstract: Omeprazole is frequently used in patients with cirrhosis of the liver to treat peptic ulcer disease. It is also used for the healing of mucosal lesions after endoscopic sclerotherapy of esophageal varices in cirrhosis and extraheptic portal vein obstruction (EHPVO). This study was carried out with the aim of determining the pharmacokinetics of omeprazole in different degrees of liver cirrhosis and in patients with EHPVO, compared with healthy volunteers. Ten healthy volunteers, 30 patients with cirrhosis of the liver, divided into 3 groups of 10 depending on severity (according to Child-Pugh classification A, B and C) and ten patients with EHPVO participated in the study. The subjects received an omeprazole 20 mg capsule after an overnight fast. Blood samples were collected at 0, 0.5, 1, 1.5, 2, 2.5, 3, 6, 9 and 24 h after drug administration. Omeprazole level in plasma was estimated by reverse-phase high performance liquid chromatography (HPLC). The elimination half-life was significantly (p < 0.05) increased to 2.38 +/- 0.16, 3.26 +/- 0,12, 3.58 +/- 0.31 and 2.59 +/- 0.22 h in patients with different grades of cirrhosis (A, B and C) and also in patients with EHPVO, respectively, compared with 1.054 + 0.10 h in healthy volunteers. A similar significant increase (p < 0.05) was observed in the AUC(0alpha), while C(max) was significantly increased to 400.40 +/- 27.89 and 602 +/- 55.13 ng/ml in only grade C cirrhosis patients and EHPVO patients, compared with 303.5 +/- 36.42 ng/ml in healthy volunteers. No significant difference was observed in T(max). It was concluded that the metabolism of omeprazole was significantly impaired in both liver cirrhosis and EHPVO in comparison with healthy volunteers.

Intermittent symptoms in neurocysticercosis: could they be epileptic?

Abstract: Objectives – Some patients with neurocysticercosis (NCC) develop perilesional gliosis during the course of healing and carry poor prognosis for the seizure control. We evaluated the clinical status of these patients during complete control of their original seizures on anti-epileptic drugs (AED). Material and methods – We studied 172 patients with solitary NCC, 45 with perilesional gliosis as visible on magnetization transfer spin echo (MTSE) magnetic resonance imaging and 127 without gliosis, for any abnormal symptom during the course of their “seizure-free” period. All of them received optimum doses of AED to control the original seizures. Results – Patients with gliosis had high incidence of abnormal symptoms with or without corresponding abnormalities on surface electroencephalogram (EEG). These symptoms disappeared on increasing the dose or adding a new AED. The symptoms, which were transient episodic in nature, included heaviness, dystonic posturing, weightlessness, numbness and alien limb phenomenon on the side of the body contralateral to cerebral lesion, and headache. Conclusion – Patients with NCC who develop perilesional gliosis during the process of healing tend to suffer from disturbing intermittent symptoms during their apparent control of seizures. The symptoms are controllable with increased dosage of previously prescribed or addition of another AED. As these symptoms could possibly be epileptic in nature, their identification and treatment may have a bearing on long-term seizure control after stopping AED therapy.