National Institute of Oceanography, India

About: National Institute of Oceanography, India is a facility organization based out in Panjim, Goa, India. It is known for research contribution in the topics: Monsoon & Population. The organization has 4713 authors who have published 6927 publications receiving 174272 citations.

Activity of the respiratory electron transport system and respiration rates within the oxygen minimum layer of the Arabian Sea

Abstract: Measurements of the activity of the respiratory electron transport system (ETS) at 15 stations in the Arabian Sea during the northeast monsoon (December 1988) yield high respiration rates that do not correlate with the trends in primary productivity. The rates are unlikely to be sustained by the supply of carbon associated with the sinking particles alone, and seem to suggest a major role for dissolved and/or suspended organic matter in fuelling oxygen consumption and denitrification. The data are utilized to compute a denitrification rate of 24–33 Tg N y−1 in the Arabian Sea. This estimate agrees with the estimate based on the exports of nitrate deficits outside the denitrification zone. The ventilation time of the denitrifying layer is calculated as ∼1 year.

Dietary supplementation of selenium nanoparticles modulated systemic and mucosal immune status and stress resistance of red sea bream (Pagrus major).

Abstract: Dietary supplementation of selenium nanoparticles (Se-NPs) at different levels (0, 0.5, 1, and 2 mg kg−1 diet) was evaluated to find out the effects on serum and skin immune responses as well as stress resistance in the red sea bream (Pagrus major). After 45 days of experimental trial, serum and mucosal immune responses were significantly high in fish fed 1 mg Se-NPs kg−1 diet (P < 0.05). In this group, alternative complement pathway, total serum protein, antioxidant activity of catalase enzyme, serum bactericidal activity, serum lysozyme activity, and amounts of skin mucus secretions as well as stress resistance against low salinity stress increased significantly, when compared to fish fed Se-NP-free diet (P < 0.05). Furthermore, fish fed Se-NPs at 2 mg kg−1 diet exhibited higher alternative complement pathway, total serum protein, mucus lysozyme activity, serum and mucus peroxidases, amount of mucus secreted, and tolerance against low salinity stress than the fish fed Se-NP-free diet (P < 0.05). Interestingly, the nitro blue tetrazolium activity in all groups fed with diets supplemented with Se-NPs are significantly higher than Se-NP-free diet (P < 0.05). The present results demonstrate that the dietary supplementation with Se-NPs (mainly from 1 to 2 mg kg−1 level) could be useful for maintaining the overall health status of red sea bream.

Resolving the Colletotrichum siamense species complex using ApMat marker

Abstract: Colletotrichum gloeosporioides sensu lato has been associated with anthracnose in diverse commercial crops. It is now established that C. gloeosporioides sensu lato comprises 33 phylogenetic species and C. gloeosporioides sensu stricto is not a common pathogen of tropical fruits. In this study, we investigated the phylogenetic relationships of 85 Colletotrichum isolates associated with select tropical fruits and flowering plants from India. In the ApMat marker analysis, the 85 isolates clustered with 7 known Colletotrichum species (C. aotearoa, C. dianesei, C. endomangiferae, C. musae, C. siamense, C. theobromicola, Glomerella cingulata f. sp. camelliae) and six novel lineages. One of the novel lineages is described and illustrated in this paper as Colletotrichum communis sp. nov., while new-host pathogen associations for C. aotearoa, C. endomangiferae, C. dianesei and C. theobromicola are reported from India. Out of the 85 isolates analysed in this paper, 73 isolates clustered within the C. siamense species complex, indicating that C. siamense species complex, not C. gloeosporioides sensu stricto, is common on tropical fruits. In comparison with act, cal, gapdh, ITS and tub2 gene markers, we recommend the use of the ApMat marker for accurate identification of cryptic species within the C. siamense species complex. We believe that the ApMat marker, in combination with one or two similar ‘phylogenetically superior’ gene markers, is a better candidate for species-level classification of fungi that were traditionally identified as ‘Colletotrichum gloeosporioides’.

On wave interactions in a stratified fluid

Abstract: Interactions between waves in a stably stratified fluid with a free or fixed upper surface may occur at second order when the horizontal wave-numbers, ki, and frequencies, σi, of the three interacting waves satisfy the relations \[ {\bf k}_1 \pm{\bf k}_2 \pm {\bf k}_3 = 0,\quad \sigma_1 \pm \sigma_2 \pm \sigma_3 = 0. \] These relations may be satisfied in the case when two free surface waves interact with an internal wave, or in the case when all three waves are internal, provided that they do not all belong to the same mode. The theory is applied to situations which might be realized in the laboratory.

The Bayesian detection of discontinuities in a polynomial regression and its application to the cycle-slip problem

Abstract: This paper deals with the problem of detecting and correcting cycle-slips in Global Navigation Satellite System (GNSS) phase data by exploiting the Bayesian theory. The method is here applied to undifferenced observations, because repairing cycle-slips already at this stage could be a useful pre-processing tool, especially for a network of permanent GNSS stations. If a dual frequency receiver is available, the cycle-slips can be easily detected by combining two phase observations or phase and range observations from a single satellite to a single receiver. These combinations, expressed in a distance unit form, are completely free from the geometry and depend only on the ionospheric effect, on the electronic biases and on the initial integer ambiguities; since these terms are expected to be smooth in time, at least in a short period, a cycle-slip in one or both the two carriers can be modelled as a discontinuity in a polynomial regression. The proposed method consists in applying the Bayesian theory to compute the marginal posterior distribution of the discontinuity epoch and to detect it as a maximum a posteriori (MAP) in a very accurate way. Concerning the cycle-slip correction, a couple of simultaneous integer slips in the two carriers is chosen by maximazing the conditional posterior distribution of the discontinuity amplitude given the detected epoch. Numerical experiments on simulated and real data show that the discontinuities with an amplitude 2 or 3 times larger than the noise standard deviation are successfully identified. This means that the Bayesian approach is able to detect and correct cycle-slips using undifferenced GNSS observations even if the slip occurs by one cycle. A comparison with the scientific software BERNESE 5.0 confirms the good performance of the proposed method, especially when data sampled at high frequency (e.g. every 1 s or every 5 s) are available.