Khare, N., Nigam, R., Hashimi, N.H.
A 2-m-long, shallow-water sediment core, representing the last 2,500 years, collected from the tropical Arabian Sea from the inner shelf (22 m water depth) off Karwar (Karnataka, India) near the...
To formulate the future plans for guarding against the furies of the nature, either due to natural or anthropogenic climatic disasters, understanding of paleoclimatic fluctuations, particularly of...
Nigam, R., Kurtarkar, S.R., Saraswat, R., Linshy, V.N., Rana, S.S.
Live specimens of benthic foraminiferal species Rosalina leei were subjected to a combination of temperature (25 degrees C, 30 degrees C and 35 degrees C) and salinity (25 ppt, 30 ppt, and 35 ppt) to...
Analytical models for Cross-correlation signal in Time-Distance Helioseismology (2007)
Nigam, R., Kosovichev, A. G., Scherrer, P. H.
In time-distance helioseismology, the time signals (Doppler shifts) at two points on the solar surface, separated by a fixed angular distance are cross-correlated, and this leads to a wave packet...
Saraswat, R., Nigam, R., Weldeab, S., Mackensen, A.
The tropical sea surface temperature (SST) is one of the important factors that regulates the amount and duration of rainfall in the tropical region, the world’s most densely populated region. The...
Panchang, R., Nigam, R., Riedel, F., Janssen, A.W., Hla, U Ko Yi
Ever since the Challenger Expedition the Indian Ocean pteropods have been recognized as important constituents of biogenic flux. Initially they were of interest only to biologists or the fishery...
Linshy, V.N., Rana, S.S., Kurtarkar, S., Saraswat, R., Nigam, R.
The laboratory culture studies, carried out on benthic foraminifera, with the aim to refine paleoceanographic / paleoclimatic or environmental application of benthic foraminifera, have been reviewed....
Rana, S.S., Nigam, R., Panchang, R.
An attempt has been made to reconstruct sea level variations along the central east coast of India during the late Pleistocene and early Holocene. A total of 39 surface sediment samples collected...
Nigam, R., Mazumder, A., Henriques, P.J., Saraswat, R.
In order to study the response of benthic foraminifera, especially the rectilinear bi- and tri-serial benthic foraminifera (RBF) to oxygen-depleted conditions from the Arabian Sea off central west...
Preface to: Marine micropaleontological studies from the northern Indian Ocean (2007)
Indian Ocean is unique, being land-locked towards the northern margin, and experiences, highest reported oceanic productivity. It is also the locale for the most severe oxygen depleted waters in the...
Foraminiferal studies on a shallow water sediment core off Karwar, central west coast of India have revealed significant changes in the monsoonal precipitation during the last around 720 years. The...
Nigam, R., Saraswat, R., Kurtarkar, S.R.
Culture experiment has been carried out to observe the response of Pararotalia nipponica (Asano) to different salinities and its salinity tolerance limits. The specimens of P. nipponica kept in 33‰...
Application of foraminifers in ecotoxicology: Retrospect, perspect and prospect (2006)
Nigam, R., Saraswat, R., Panchang, R.
In view of the extensive use of foraminifers for the pollution monitoring especially their unmatched utility in deciphering the temporal variation in the type and concentration of pollutants at a...
Effect of oxygen manipulations on benthic foraminifera: A preliminary experiment (2006)
Panchang, R., Nigam, R., Linshy, V., Rana, S.S., Ingole, B.S.
Three sediment cores were collected at 50 m water depth on the west coast of India, off Ratnagiri, and were subjected to oxygen manipulations maintaining natural temperature and salinity. The...
The study of 134 subsurface sediment samples from three cores collected along the Coast of Kachchh, off Gujarat Province, NW India, shows the presence of 151 foraminifer species. Q-mode cluster...
During the past few decades, microfossils, especially foraminifers have become the prime source to address paleo-environmental issues. These microfossils also find application in marine...
Saraswat, R., Nigam, R., Barreto, L.
Temporal variation in abundance and mean proloculus diameter of the benthic foraminiferal species Epistominella exigua has been reconstructed over the last approx. 50,000 yr BP, from a core collected...
Addressing environmental issues through foraminifera – Case studies from the Arabian Sea (2005)
The present global scenario poses multiple environmental problems such as the green house effect, ozone holes, global warming and consequential sea level rise, all being attributed to anthropogenic...
A foraminiferal testimony for the reduced adverse effects of mining in Zuari Estuary, Goa (2005)
Panchang, R., Nigam, R., Baig, N., Nayak, G.N.
This paper demonstrates the potentiality of foraminifera in detecting mining pollution. Goa's Mandovi-Zuari estuarine complex is most vulnerable to deterioration caused by the mining industry. The...
Saraswat, R., Nigam, R., Weldeab, S., Mackensen, A., Naidu, P.D.
Sea surface temperature (SST) for the central equatorial Indian Ocean, has been reconstructed over the last approx. 137 kyr, from Mg/Ca of the planktonic foraminiferal species Globigerinoides ruber....
Saraswat, R., Nigam, R., Barreto, L.
Temporal variation in abundance and mean proloculus diameter of the benthic foraminiferal species Epistominella exigua has been reconstructed over the last approx. 50,000 yr BP, from a core collected...
Nigam, R., Panchang, R., Banerjee, P.
Foraminiferal characteristics of 11 surface sediment samples collected from the Mandovi estuary during 2001 have been compared with similar data based on samples collected during 1994. The study...
Sediment traps as a new tool for estimation of longevity of planktonic foraminifera (2005)
Sediment trap technique provides time series data of sinking particles (faunal and sediment) from surface to bottom of the sea. Besides many other applications, data can also be used to estimate life...
Nigam, R., Mazumder, A., Saraswat, R.
The rare presence of the agglutinated foraminiferal species Ammolagena clavata is presented for the first time from the Recent sediments of the Indian Ocean region. This species has previously been...
Foraminifers as indicators of marine pollution: A culture experiment with Rosalina leei (2004)
Saraswat, R., Kurtarkar, S.R., Mazumder, A., Nigam, R.
In order to develop a viable foraminiferal proxy for heavy metal pollutants, juvenile specimens of Rosalina leei were subjected to different mercury concentrations (0 -180 ng/l). Initially...
Distribution of benthic foraminifera within oxygen minima zone, off central west coast, India (2003)
Mazumder, A., Henriques, P.J., Nigam, R.
A total of 128 surface sediment samples (76 grab and 52 core top samples) were analyzed for benthic foraminiferal contents from the region off Goa, India in the eastern Arabian Sea upto a water depth...
Saraswat, R., Mazumder, A., Kurtarkar, S.R., Nigam, R., Ganguly, A.
Despite the extensive use of foraminiferal proxies for paleoclimatic reconstructions, the question how and why morphologic variations of foraminifera are regulated by climatic changes remains a...
Life spans of planktonic foraminifers: New sight through sediment traps (2003)
Nigam, R., Saraswat, R., Mazumder, A.
Determinig the life spans of planktonic foraminifera is vital in view of their increasing use for palaeoclimtic studies. Till date all the estimates about life span of planktonic foraminifers are...
Has sea level fluctuations modulated human settlements in Gulf of Khambhat (Cambay)? (2002)
In the same sequence, the recent discovery of Neolithic settlements in Gulf of Khambhat is really exciting and a milestone in the field of marine archaeology. As described "the materials collected at...
Gandhi, S., Rajamanickam, G.V., Nigam, R.
A systematic study of benthic foraminifera has been made on 42 sediment samples collected between Mandapam and Kodiyakkarai, off Palk Strait, Tamil Nadu, India. A total of 102 benthic foraminiferal...
Does mining pollution affect foraminiferal distribution in Mandovi estuary, Goa, India? (2002)
Nigam, R., Nayak, G.N., Naik, S.
A total of 10 surface sediment samples were collected in the premonsoon season in 1990 from the Mandovi estuary, Goa, India. Study revealed presence of 14 species of foraminifera. The foraminiferal...
Pathak, M.C., Sinha, R., Nigam, R., Gujar, A.R., Kotnala, K.L.
The Indian coastal region has a privileged combination of valuable nature resources and unique landscape. That is why living on the coast and utilising these natural resources are as old a process as...
Numerical Simulations of Oscillation Modes of the Solar Convection Zone (2000)
D. Georgobiani, A. G. Kosovichev, R. Nigam, A. Nordlund, R. F. Stein
We use the three-dimensional hydrodynamic code of Stein and Nordlund to realistically simulate the upper layers of the solar convection zone in order to study physical characteristics of solar...
The possible effects of environmental factors on the dimorphic mode of reproduction in benthic foraminifera have been reported in the literature. Published observations based on field samples have...
Nigam, R., Khare, N., Mayenkar, D.N.
The foraminiferal content of one hundred eight modern marine sediment samples off Vengurla-Cochin sector (ranging in water depth from 30 to 1330 m). West Coast of India was studied. A total of two...
Laboratory experiment to record rate of movement of cultured benthic foraminifera (2000)
Sensitivity of foraminifera towards environmental / climatic changes, makes them a distinct proxy of paleoclimatic conditions. In order to use these micro organisms for paleoclimatic reconstruction,...
Sinha, R., Nigam, R., Khare, N., Ingole, B.S., Ghosh, D.N.
During the 4th and 6th Indian Expedition to Antarctica, surface sediment samples were collected from eight stations in the Queen Maud Land Shelf, Lazarev Sea from the depth ranging from 157 to 785 m....
Chaturvedi, S.K., Nigam, R., Khare, N.
A total of seven surface sediment samples collected within 4.4 m to 13.9 m water depth (below chart datum) from Kharo Creek were studied for their foraminiferal content. The study reveals forty seven...
Katha, P.K., Bhalla, S.N., Nigam, R.
Q-Mode cluster analysis of one hundred sixty species of Recent foraminifera from twenty nine Recent littoral-thanatotopes from 4000 km long coastal-stretch of India reveals that its west and east...
Foraminiferal study from Kharo Creek, Kachchh (Gujarat), north west coast of India (2000)
A total of seven surface sediment samples collected within 4 to 13.5 m water depth below chart datum from Kharo Creek, Gujarat, India were studied for their foraminiferal content. The study revealed...
Simulations of Oscillation Modes of the Solar Convection Zone (1999)
Georgobiani, D., Kosovichev, A. G., Nigam, R., Nordlund, A., Stein, R. F.
We use the three-dimensional hydrodynamic code of Stein and Nordlund to realistically simulate the upper layers of the solar convection zone in order to study physical characteristics of solar...
Internal Structure And Rotation Of The Sun: First Results From The MDI Data (1997)
R. S. Bogart, R. I. Bush, J. T. Hoeksema, J. Aloise, L. Bacon, A. Burnette, ...
. The Medium-l Program of the Michelson Doppler Imager (MDI) instrument on board SOHO provides continuous observations of oscillation modes of angular degree, l, from 0 to ¸ 300. The initial results...
A simple model for solar oscillations using a delta function source is developed. From this the power spectrum is computed for different values of the source location and for various values of...
Study Of Solar High-Frequency Modes Near The Acoustic Cut-off Frequency (1997)
. The acoustic cut-off frequency ac is related to the height of the potential barrier near the solar surface. Acoustic waves with frequencies greater than ac are only partially reflected by the...
Structure And Rotation Of The Solar Interior: Initial Results From The Mdi Medium-L Program (1997)
A. G. Kosovichev, J. Schou, P. H. Scherrer, R. S. Bogart, R. I. Bush, J. T. Hoeksema, ...
. The Medium-l Program of the Michelson Doppler Imager instrument on board SOHO provides continuous observations of oscillation modes of angular degree, l, from 0 to ¸ 300. The data for the Program...
Structure And Rotation Of The Solar Interior: Initial Results From The Mdi Medium-L Program (1997)
A. G. Kosovichev, J. Schou, P. H. Scherrer, R. S. Bogart, R. I. Bush, J. T. Hoeksema, ...
. The Medium-l Program of the Michelson Doppler Imager instrument on board SOHO provides continuous observations of oscillation modes of angular degree, l, from 0 to ¸ 300. The data for the Program...
Nigam, R., Khare, N., Koli, N.Y.
A laboratory culture programme is established to extend credibility to foraminiferal-based techniques being used to generate the high-resolution proxy records for palaeoclimatic reconstruction. In...
Changes in coiling direction in foraminifera have been used extensively as proxy data for paleoclimates. However, most of the studies centred around planktonic foraminifera, and various causes...
The effects of speech output technology in the learning of graphic symbols.
Schlosser, R W, Belfiore, P J, Nigam, R, Blischak, D, Hetzroni, O
The effects of auditory stimuli in the form of synthetic speech output on the learning of graphic symbols were evaluated. Three adults with severe to profound mental retardation and communication...
Three times daily or 8-hourly.
Nigam, R, Loveday, B J, Grainger, S L, Maxton, D G
The timing of drug ingestion over 24 hours was assessed in 58 outpatients taking drugs three times daily. The mean time between 1st and 2nd dose was 5.7 hours, 2nd and 3rd 6.1 hours and between 3rd...
The effects of speech output technology in the learning of graphic symbols.
Schlosser, R W, Belfiore, P J, Nigam, R, Blischak, D, Hetzroni, O
The effects of auditory stimuli in the form of synthetic speech output on the learning of graphic symbols were evaluated. Three adults with severe to profound mental retardation and communication...
Three times daily or 8-hourly.
Nigam, R, Loveday, B J, Grainger, S L, Maxton, D G
The timing of drug ingestion over 24 hours was assessed in 58 outpatients taking drugs three times daily. The mean time between 1st and 2nd dose was 5.7 hours, 2nd and 3rd 6.1 hours and between 3rd...