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1

Digitale Medien

Trends in structural compositional attributes of dune-interdune vegetation and their edaphic relations in the Indian desert (1996)

Kumar, Suresh

Springer

Plant ecology 124 (1996), S. 73-93

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ISSN: 1573-5052

Schlagwort(e): Classification ; Ordination ; Soil moisture ; Soil reaction ; Spiny & browse plants ; diversity ; degradation

Quelle: Springer Online Journal Archives 1860-2000

Thema: Biologie

Notizen: Abstract Vegetation of 127 sites on different aspects of dune-interdunes in the Indian Thar Desert was classified using TWINSPAN. TWINSPAN groupings of sites separated better vegetated dunes of the northeast form the poorly vegetated dunes of the northwest and the southwest. Of the different ordinations using noncentred, centred and centred and standardized principal component analysis, reciprocal averaging and detrended correspondence analysis (DCA), the site and species classes in DCA correlated well with ten edaphic and ten vegetational attributes of each site. Strong correlation of vegetation groupings with soil texture, moisture holding capacity and low correlation with pH and electrical conductivity revealed the possible importance of soil physical properties in affecting vegetation composition. The 11 species classes in TWINSPAN were regrouped into 18 species classes in DCA, which separated highly frequent species from those of less and least frequent species. Based on dominance-diversity attributes, Calligonum polygonoides-Lasiurus sindicus was brought out as bioedaphic climax stage. Correlation of ordination scores in different site groupings with vegetational attributes showed specific trends: From the zero of x, y and z axes to their maximum, the ordination scores of grasses and browse species declined while score of spinous species increased. The sites near the origin of the x, y and z axes were therefore least degraded and those at or near the maximum of x, y & z axes were most disturbed as was confirmed by the dominance diversity trends. Thus trends of compositional and functional attributes of vegetation of sites in different groupings helped in inferring a site's degradation status.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00045146

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2

Digitale Medien

Impact of overgrazing on seed predation by rodents in the Thar desert, northwestern India (1995)

Wada, Naoya ; Narita, Kenji ; Kumar, Suresh ; [weitere]

Springer

Ecological research 10 (1995), S. 217-221

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ISSN: 1440-1703

Schlagwort(e): desert rodents ; overgrazing ; seed predation ; succession ; Thar desert

Quelle: Springer Online Journal Archives 1860-2000

Thema: Biologie

Notizen: Abstract We compared the vegetation structure, rodent density and seed loss rate between protected and disturbed sites affected from grazing by cattle, goats and sheep, in the Thar desert of India. A perennial tussocky grassLasiurus sindicus Hent. was largely dominant in the protected site, whileL. sindicus was rare and replaced by undershrub speciesAerva pseudotomentosa Blatt. & Halb. andCrotalaria burbira Buch.-Ham. in the overgrazed site. In the grazed site, plant coverage was low, but the density of rodent burrows and the frequency of rodent captures were significantly high as compared to the protected site. Corresponding with the density of desert rodents, seed predation was significantly higher in the grazed site than in the protected site. These results suggest that overgrazing by large mammals has strong effects on plant succession by altering not only the species composition and abundance of plant community, but also the habitat suitability for seed-eating rodents.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF02347944

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3

Digitale Medien

Growth of world and Indian physics literature (1999)

Gupta, B. M. ; Sharma, Praveen ; Kumar, Suresh

Springer

Scientometrics 44 (1999), S. 5-16

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ISSN: 1588-2861

Quelle: Springer Online Journal Archives 1860-2000

Thema: Buch- und Bibliothekswesen, Informationswissenschaft , Wissenschaftskunde und Wissenschaftsorganisation, Hochschul- und Universitätswesen, Museumswissenschaft

Notizen: Abstract The paper deals with the nature of growth models currently used in the literature for modeling the growth of publications. It introduces briefly three growth models and explores the applicability of these models in the growth of world and Indian physics literature. The analysis suggests that the growth of Indian physics literature follows a logistic model, while the growth of world physics literature is explained by a combination of logistic and power models. The criteria for selection of growth models based on the new growth rate functions suggested by Egghe and Ravichandra Rao are given. The methodology suggested by Egghe and Ravichandra Rao is shown to work satisfactorily, except for longer time series growth data, when we may have to restore to data splitting approach, if suggested by the plots of new growth rate functions. This approach helped us to use a combination of two growth models instead of one, to explain the growth of world physics literature.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF02458474

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4

Digitale Medien

A comparision of productivity of male and female scientists of CSIR (1999)

Gupta, B. M. ; Kumar, Suresh ; Aggarwal, B. S.

Springer

Scientometrics 45 (1999), S. 269-289

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ISSN: 1588-2861

Quelle: Springer Online Journal Archives 1860-2000

Thema: Buch- und Bibliothekswesen, Informationswissenschaft , Wissenschaftskunde und Wissenschaftsorganisation, Hochschul- und Universitätswesen, Museumswissenschaft

Notizen: Abstract The paper examines the scientific productivity of male and female scientistts working in the Council of Scientific and Industrial Research (CSIR), India at the overall agency level and at the group of laboratories level, characterized by three broad subjects of physical, biological, and engineering sciences. The productivity of scientists is evaluated on the basis of three parameters: the extent of scientists not publishing any paper, the average number of papers per scientist, and using Lotka's approach. In order to find out whether there is any significant difference between male and female productivity distributions, a Chi-square test is used. Studies the applicability of Lotka's inverse power law and some other statistical models in the distribution of scientific productivity of male and female scientists. Concludes that no significant difference exists between productivity distributions of male and female scientists.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF02458437

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5

Digitale Medien

Applicability of selected probability distributions to the number of authors per article in theoretical population genetics (1998)

Gupta, B. M. ; Kumar, Suresh ; Rousseau, R.

Springer

Scientometrics 42 (1998), S. 325-334

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ISSN: 1588-2861

Quelle: Springer Online Journal Archives 1860-2000

Thema: Buch- und Bibliothekswesen, Informationswissenschaft , Wissenschaftskunde und Wissenschaftsorganisation, Hochschul- und Universitätswesen, Museumswissenschaft

Notizen: Abstract Recently scientists have investigated what statistical distributions can be used to describe the distribution of the number of authors per article.Ajiferuke has undertaken the most comprehensive study of this problem. He has found that by and large the Inverse Gaussian-Poisson distribution could describe most properly the observed authorship distributions. However, it is well known that this distribution is rather intricate, soRousseau tried to fit some simple one-parameter distributions to the number of authors of LIS articles. He has found that the geometric and the truncated Poisson distribution adequately describe these authorship data sets. The main purpose of the present paper is to continue these investigations and to analyse and test the viability of simple statistical distributions. As to (sub)fields where the single author dominates the results ofRousseau were corroborated: the truncated Poisson and the geometric distribution give often adequate fits to describe the number of authors. The Lotka distribution should be rejected. The truncated binomial distribution and the truncated negative binomial were investigated as well. However, it is not clear whether they are acceptable candidates.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF02458375

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6

Digitale Medien

Impact of SERC's funding on research in chemical sciences (1998)

Jain, Ashok ; Garg, K. C. ; Sharma, Praveen ; [weitere]

Springer

Scientometrics 41 (1998), S. 357-370

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ISSN: 1588-2861

Quelle: Springer Online Journal Archives 1860-2000

Thema: Buch- und Bibliothekswesen, Informationswissenschaft , Wissenschaftskunde und Wissenschaftsorganisation, Hochschul- und Universitätswesen, Museumswissenschaft

Notizen: Abstract The paper assesses impact of Science and Engineering Research Council (SERC) funding in chemical sciences during 1976–1989 using scientometric techniques. Other indicators like awards won, fellowship to prestigious academies, membership to editorial boards received by the project investigators, Ph.D. degrees awarded, collaborations established and new courses introduced due to SERC funding have also been analyzed. The study indicates that activity index of research out put in various frontier areas of chemical sciences have gone up despite a decrease in Indian activity index in these areas. The growth pattern of papers for “Organometallic and Organometalloidal Compounds” are similar for India and world. Contribution of SERC's project investigators in high impact factor (≥2) journals and the citations received by the papers published by them are higher than Indian contributions in chemical sciences. The SERC funding has resulted in a three fold increase in the number of Ph.D. degrees awarded in chemical sciences and SERC project investigators have won many prestigious awards, fellowship to academies and membership of the editorial board of the journals. The SERC funded research has also resulted in new courses at various universities.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF02459051

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7

Digitale Medien

Collaboration profile of theoretical population genetics speciality (1997)

Gupta, B. M. ; Kumar, Suresh ; Karisiddappa, C. R.

Springer

Scientometrics 39 (1997), S. 293-314

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ISSN: 1588-2861

Quelle: Springer Online Journal Archives 1860-2000

Thema: Buch- und Bibliothekswesen, Informationswissenschaft , Wissenschaftskunde und Wissenschaftsorganisation, Hochschul- und Universitätswesen, Museumswissenschaft

Notizen: Abstract Traces the growth of collaborated and funded research as reflected in research papers in theoretical population genetics research speciality from 1916–80 through a case study. Analyses the proportion and extent of collaborated papers, averge number of authorship per paper, and collaborative coefficient index of research papers thereby giving an overall perspective of the growth of professionalism in the field. Studies the relation between collaboration, productivity, and funding of research papers in theoretical population genetics. Classifies the total collaborative papers/authors by type of collaboration and studies the trends and shifts in the nature and type of collaborative research over the years.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF02458532

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8

Digitale Medien

Differential gene expression of extracellular matrix components in dilated cardiomyopathy (1996)

Tyagi, Suresh C. ; Kumar, Suresh ; Voelker, Donald J. ; [weitere]

New York, N.Y. : Wiley-Blackwell

Journal of Cellular Biochemistry 63 (1996), S. 185-198

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ISSN: 0730-2312

Schlagwort(e): extracellular matrix ; remodeling ; collagenase ; collagen ; dilated cardiomyopathy ; congestive heart disease ; end-stage heart failure ; matrix metalloproteinase ; tissue inhibitor of metalloproteinase ; differential display mRNA analysis ; gene expression ; Life and Medical Sciences ; Cell & Developmental Biology

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Biologie , Chemie und Pharmazie , Medizin

Notizen: Extracellular matrix metalloproteinases (MMPs) are activated in dilated cardiomyopathic (DCM) hearts [Tyagi et al. (1996): Mol Cell Biochem 155:13-21]. To examine whether the MMP activation is occurring at the gene expression level, we performed differential display mRNA analysis on tissue from six dilated cardiomyopathy (DCM) explanted and five normal human hearts. Specifically, we identified three genes to be induced and several other genes to be repressed following DCM. Southern blot analysis of isolated cDNA using a collagenase cDNA probe indicated that one of the genes induced during DCM was interstitial collagenase (MMP-1). Northern blot analysis using MMP-1 cDNA probe indicated that MMP-1 was induced three- to fourfold in the DCM heart as compared to normal tissue. To analyze posttranslational expression of MMP and tissue inhibitor of matrix metalloproteinase (TIMP) we performed immunoblot, immunoassay, and substrate zymographic assays. TIMP-1 and MMP-1 levels were 37 ± 8 ng/mg and 9 ± 2 ng/mg in normal tissue specimens (P 〈 0.01) and 2 ± 1 ng/mg and 45 ± 11 ng/mg in DCM tissue (P 〈 0.01), respectively. Zymographic analysis demonstrated lytic bands at 66 kDa and 54 kDa in DCM tissue as compared to one band at 66 kDa in normal tissue. Incubation of zymographic gel with metal chelator (phenanthroline) abolished both bands suggesting activation of neutral MMP in DCM heart tissue. TIMP-1 was repressed approximately twentyfold in DCM hearts when compared with normal heart tissue. In situ immunolabeling of MMP-1 indicated phenotypic differences in the fibroblast cells isolated from the DCM heart as compared to normal heart. These results suggest disruption in the balance of myopathic-fibroblast cell ECM-proteinase and antiproteinase in ECM remodeling which is followed by dilated cardiomyopathy. © 1996 Wiley-Liss, Inc.

Zusätzliches Material: 9 Ill.

Materialart: Digitale Medien

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