Diversity of species assemblages of islands: predictions and their test using tree species composition of shola fragments

Based on all possible combinations of species that can theoretically exist on islands of different sizes, we estimated similarities among islands of equal size in their species compositions. We found that similarity coefficients among islands of equal sizes increases and the coefficients of variation for similarities decreases with increase in the size of islands. Accordingly, it can be predicted that the species compositions of small fragments shall be more diverse compared to large fragments. We tested this prediction using the tree species composition of the shola fragments at BR Hills, Western Ghats. Similarities among sholas were measured as coefficients of correlation between the frequencies of species in them and also as proportions of species shared among sholas. Small sholas were less similar and shared fewer species among themselves, compared to medium and large sholas. Also, small sholas showed higher coefficient of variation for the correlation coefficients and for proportion of species shared than medium or large sholas. In other words, species assemblage diversity among sholas was found to decrease with their size and large islands appeared to converge towards a common assemblage of species. Based on our results, we argue that small fragments add structural and functional heterogeneity to the ecosystem and hence are as important as are the large fragments in conserving biodiversity

War of hormones over resource allocation to seeds: strategies and counter-strategies of offspring and maternal parent

It is suggested that maternal parent and offspring have conflicting interests over the extent of resource allocation to developing seeds. While maternal parent would be selected to allocate her resources optimally among her offspring, the latter would be selected to demand more. In animals, offspring are known to demand additional resources either visibly (through intense vocal calls) or subtly through the production of hormones. In plants though parent offspring conflict over resource allocation has been invoked, the mechanism through which the parent and offspring interact in regulating resource allocation into developing seeds is not yet clear. In this paper, we propose that the strategies and counter-strategies of the offspring and mother during the development of seeds might be manifested through the production of appropriate growth hormones. Accordingly, we predict (i) hormones that mobilize resources into seeds (e.g. auxins and gibberellic acid) shall be synthesized exclusively by the offspring tissue and (ii) hormones that inhibit resource flow in to seeds (e.g. abscisic acid) be produced exclusively by the maternal tissue. We show that these predictions are supported by existing literature on the temporal dynamics and source of production of growth hormones during seed development. Finally, we suggest that such analysis viewing the production of different hormones during early seed development, as strategies and counter-strategies of mother and offspring tissue, helps ofer a meaningful interpretation of the otherwise complex dynamics of hormone fluxes

Evaluation of opioid sparing effect of dexmedetomidine and pregabalin using acute pain model in male wistar rats

Background: Adjuvant analgesics are added to pain management regimen to reduce opioid consumption and minimise their side effect. Newer ones like dexmedetomidine and pregabalin have not been thoroughly researched. Objectives of the study to study the opioid sparing effect of dexmedetomidine and pregabalin using tail flick and hot plate method in male wistar rats.Methods: Forty two rats were grouped into seven groups with six in each group. Analgesic activity was tested using tail flick, where in the reaction time to flick its tail on a heated surface was noted. In the hot plate method, the reaction time to withdraw or lick the paws when placed on heated surface was noted.Results: The reaction time to flick its tail was prolonged with dexmedetomidine and pregabalin when combined with opioids even in sub therapeutic doses.Conclusion: Adjuncts like dexmedetomidine and pregabalin can be very useful  in mutimodal pain management and also to reduce the opioid consumption

Floral resources of Karnataka: a geographic perspective

We compiled the data on the floral resources of Karnataka from diverse published sources and analysed the geographic patterns of distribution of floral diversity. Our database shows that Karnataka harbours 4758 species from 1408 genera and 178 families and accounts for about 27 per cent of the country's floral diversity. We computed the 'endemicity value' of different districts based on the number of endemic species (those restricted to a maximum of five districts) harboured by them and found that the most species-rich districts (viz. Uttara Kannada, Dakshina Kannada, Mysore, Hassan, Udupi and Kodagu) were also characterized by high values of endemicity while the species-poor districts had low values of endemicity. However, the relation between the species richness and endemicity of the districts was not linear; the species richness increases abruptly at lower levels of endemicity but plateaus off later at high levels of endemicity. Based on the number of species packed into the families, all the 27 districts segregated distinctly into three clusters that geographically correspond with the three major agro-climatic zones of the state. Our analysis showed that though the districts along the Western Ghats are florally rich, those along the dry tracts also harbour certain unique elements of the flora; thus these dry zone districts appear to be as important as those along the Western Ghats in conserving the floral resources

जलवायु परिवर्तन के नियंत्रण में सामाजिक भूमिका (Societal role in curbing climate change-ClimEd Series:3B)

An increase in earth's average atmospheric temperature that causes corresponding changes in climate due to the greenhouse effect such as carbon dioxide emissions from burning fossil fuels / deforestation

Does forest type classification reflect spatial dynamics of vegetation? An analysis using GIS techniques

The existing methods of classification of forest vegetation rely more on the structure and composition of tree vegetation with little information derived from other layers. We suggest that any classificatory process of forest vegetation should consider the spatial dynamics of all the three layers namely, tree, shrub and herb. In this paper we have attempted to offer an objective method of classifying the vegetation at all the three layers utilizing GIS and multivariate statistical tools. Unlike the existing techniques, our method views the forest as a continuously changing mosaic of vegetation and not as an assemblage of discrete patches. Our study suggests that understanding the spatial dynamics of vegetation at one layer may not reflect that at others. Further, as an alternate to the existing methods, we also develop a continuum map of biodiversity of the forest that offers. the conservation value of each patch, an element that IS not conveyed in the existing classificatory processes

MT-MADRAS brightness temperature analysis for terrain characterization and land surface microwave emissivity estimation

This article reports the potential of the ‘MADRAS’ payload on-board the Megha-Tropiques satellite for land surface studies. The analysis has been divided into two parts as application of MADRAS data for studying the land surface properties and estimation of microwave emissivity directly from MADRAS brightness temperature (TB) data by applying an in-house developed Microwave Radiative Transfer Computation Code. The derived emissivity is further used to characterize the microwave emissivity of different land surface classes. The polarization difference (PD) parameters, the difference between horizontal (H-) and vertical (V-) polarization of TBs at 18 and 36 GHz clearly discern surface features of different surface classes such as deserts, arid/semi-arid an d vegetated regions. Land surface microwave emissivity for MADRAS channels is derived on a global basis. These are inter-compared with the emissivity derived from the operational TRMM Microwave Imager and are in reasonably good agreement. The analysis based on emissivity shows spectral variation for different surface classes

Genetic relatedness among developing seeds and intra fruit seed abortion in Dalbergia sissoo (Fabaceae)

Dalbergia sissoo, a wind-dispersed tropical tree, exhibits high intrafruit seed abortion. Of the four to five ovules in the flower, generally one and occasionally two or three develop to maturity. It has been proposed that the seed abortion is a consequence of intense sibling competition for maternal resources and that this competition occurs as an inverse function of the genetic relatedness among the developing seeds. Accordingly, developing seeds compete intensely when they are genetically less related but tend to develop together when genetically more related. We tested this hypothesis by comparing the genetic similarity among the pairs of seeds developing within a pod with that among (a) random pairs from the pool of all seeds, (b) random pairs from single-seeded pods, and (c) random pairs from two-seeded pods, using both randomly amplified polymorphic DNA (RAPD) and isozymes in five trees. We found that the pairs of seeds developing within a pod are genetically more similar than any random pairs of seeds in a tree. Thus the formation of two-seeded pods appear to be associated with increased genetic relatedness among the developing seeds. We discuss the results in the context of possible fitness advantages and then discuss the possible mechanisms that promote tolerance among related seeds

Status of vitamin D, paratharmone and serum calcium levels in perimenopausal women and their mutual correlation

Background: The present study was carried out with an aim to assess Vitamin D, parathyroid hormone and calcium status in perimenopausal women and to find out their mutual correlation.Methods: The present work was carried out on in the Department of Obstetrics and Gynaecology, in collaboration with Department of Biochemistry at Era's Lucknow Medical College and Hospitals, Lucknow, U.P. 80 healthy females aged 40-50 years were included in the study. Serum vitamin D, parathyroid hormone and calcium levels were assessed. Data was analyzed using ANOVA and Pearson correlation coefficient.Results: Osteopenia and osteoporosis was seen in 33 (41.3%) and 21 (26.3%) women respectively, 50 (62.5%) women had S. vitamin D levels 0.05). Correlation between Vitamin D levels and Parathyroid hormone levels was weak and not significant.Conclusions: The findings of present study highlighted that perimenopausal phase should be regarded as a transition phase where a lot of physiological changes take place resulting in bone mineral density loss and fall in serum hormonal, vitamin and mineral levels. Owing to tremendous continuing changes the relationship between these parameters is vitiated and does not show a systematic change.

Exploited seerfish fisheries of india during 1998-02

Seerfishes are esteemed table fishes. In India, they are considered as one of the high value resources due to their superior quality meat, high economic return and export market. Seerfish fishery is important to artisanal fishermen who use driftnet/gillner/hooks and line employing country crafts with or without out-board engines and medium size boats with inboard engines, in the coastal waters of 25- 60 m depth. They are the target species for to 16.9% during 1998-02 indicating attainment of optimum production. The annual production during 1998-02 varied from 42,578 t in 2001 to 54,871 t in 1998 with an average of 48,847t forming 1.9% of the marine fish landing of the country. The east coast which ranked first in seerfish production during 1950s and 1960s with around 60% contribution had progressively been reduced to 40% in 1990s and during 1998-02