Car Nicobar Research Articles

Pharmacognostic studies on Terminalia citrina (Gaertn) Roxb. ex Fleming

Terminalia citrina (Gaertn.) Roxb. ex Fleming synonym Terminalia multiflora Merr. is commonly known as Yellow Myrobalan and Manahei in Manipuri. It is highly medicinal plant which is distributed in North East India and Car Nicobar Island. Its bark is diuretic and cardio tonic and fruits are used similar to Terminalia chebula and used in various drug preparations, which are sometimes adulterated with other plant materials. In order to standardize the drug, detail morphological, anatomical (T.S. of bark, petiole and leaf; T.S., T.L.S. and R.L.S. of wood and maceration of bark and wood) and dermatological studies were undertaken.T.S. of bark showed peculiarities as-bundles of fibre and patches of stone cells, compound crystals and compound starch grains. Maceration of bark showed unique branched phloem fibres, and thin and thick walled phloem parenchyma and various crystals. T.S. of bark showed Vessels in groups of 2-9. Parenchymatous rays mostly uniseriate, rarely biseriate, heterogenous with deposition of starch grains. Maceration of wood reveled the diagnostic features like-pitted xylem parenchyma, branched xylem fibres with pits, various types of vessel elements with oblique end walls with or without long beaks, pits alternate. Tracheids tubular, thick walled with small and few pits.It was observed that Terminalia citrina (Gaertn.) Roxb. ex Fleming can be easily standardized on the basis of combination of these parameters which are peculiar to this species.

Molecular differentiation of nocturnally periodic and diurnally sub-periodic Wuchereria bancrofti by Randomly Amplified Polymorphic DNA (RAPD).

Wuchereria bancrofti, a nematode parasite, is responsible for causing 90% of lymphatic filariasis infection in the world. In India, W. bancrofti exists in two physiological forms, nocturnally periodic in the main land and diurnally sub-periodic in Car Nicobar group of islands. Differentiation of these two parasitic forms by conventional microscopic methods difficult requiring good skill and hence tedious. Therefore, we developed a simple and rapid Random Amplified Polymorphic DNA (RAPD) assay to differentiate these parasitic forms. Also, the phylogenetic relationship between periodic and sub-periodic W. bancrofti and also Brugia malayi populations was analyzed using RAPD profile generated. Distinct RAPD profiles were observed among the three parasites with the formation of three distinct clusters in the phylogenetic tree. Substantial genetic diversity (Nei's genetic diversity H) was observed among periodic (H=0.0577) and sub-periodic (H=0.1415) W. bancrofti populations.

Recent records of snakes (Squamata: Serpentes) from Nicobar Islands, India

Andaman and Nicobar Islands support a significant proportion of India’s herpetofauna. We conducted surveys for herpetofauna in the Nicobar Islands during 2008-2009. The Malayan Wolfsnake Lycodon subcinctus was recorded from Nicobar Islands for the first time. We also recorded Tiwari’s Wolfsnake Lycodon tiwarii from Car Nicobar Island for the first time since the original description. A large Colubrid Snake (Coelognathus sp.) of unknown identity was recorded from Great Nicobar Biosphere Reserve. These new records point to the inadequacy of surveys in the Andaman and Nicobar Islands, which may harbor several more unknown species.

Identification of seven scleractinian corals from Andaman and Nicobar Islands as new record to IndianWater

Andaman and Nicobar Islands are the most diverse areas with enriched marine organisms. Presence of corals in any area shows the enriched productivity of marine ecosystem of that area. The coral helps the other associated faunal communities for their survival as well as their way of life towards the future generation. Seven species of scleractinian corals are recognized as the new records to Indian water as the survey made in Neil, Tarmugli and Car Nicobar Islands of Andaman & Nicobar Archipelago. They are — Acropora tanegashimensis (Veron, 1990), Acropora insignis (Nemenzo, 1967), Favites paraflexuosa (Veron,2002), Favites spinosa (Klunzinger, 1879), Solenastrea bournoni (Milne Edwards and Haime, 1849), Porites porites (Pallas, 1766) and Seriatopora aculeate (Quelch, 1846). These scleractinian corals belong to Acroporidae, Faviidae, Poritidae and Pocilloporidae families. The present investigation deals with their morphological characteristics with relative nomenclatural attributes to draw the ideal identifying remarks.

High chloroquine treatment failure rates and predominance of mutant genotypes associated with chloroquine and antifolate resistance among falciparum malaria patients from the island of Car Nicobar, India

An in vivo chloroquine efficacy study was undertaken on the island of Car Nicobar because a temporal rise in the Plasmodium falciparum parasite population containing mutations in the chloroquine resistance transporter (PfCRT) protein has been reported there. A WHO protocol with a 28 day follow-up schedule was used for chloroquine efficacy studies. Finger-prick blood from P. falciparum malaria patients was used for sequencing the genes encoding PfCRT (exon 2), dihydrofolate reductase (PfDHFR) and dihydropteroate synthetase (PfDHPS). The majority of patients showed chloroquine treatment failure (60.42%, n=48). A higher early treatment failure (ETF) rate was recorded among non-responders (23 of 29, 79.31%). Each patient, irrespective of their chloroquine response, was infected with P. falciparum that contained mutated PfCRT (predominantly genotype C72V73I74E75T76) associated with high chloroquine resistance and none with the wild-type pfcrt gene. Therefore, mutated PfCRT was also present in the P. falciparum isolates of all the chloroquine responders. The majority of individuals from both groups also contained parasites with a high number of two-locus PfDHFR-PfDHPS mutations, associated with a high level of antifolate resistance. There is a predominance of chloroquine- and antifolate-resistant P. falciparum malaria in Car Nicobar, requiring an alternative antimalarial drug treatment policy, such as implementation of artesunate combination therapy (ACT), for this island.

Emergence of an Unusual Sulfadoxine‐Pyrimethamine Resistance Pattern and a Novel K540N Mutation in Dihydropteroate Synthetase inPlasmodium falciparumIsolates Obtained from Car Nicobar Island, India, after the 2004 Tsunami

Enormous amounts of drugs were used to contain the outbreak of infectious diseases in areas of India affected by the tsunami in December 2004. The impact of this drug use on the Plasmodium falciparum population needs to be investigated. The nucleotide sequence of the pfcrt, pfdhps, and pfdhfr genes was determined for 229 clinical P. falciparum isolates collected from patients on Car Nicobar Island at 6 different time points between May 2004 and May 2008. Over time, there was an increase in the proportion of the P. falciparum population that had mutations in the pfcrt, pfdhps, and pfdhfr genes associated with higher levels of chloroquine, sulfadoxine, and pyrimethamine resistance, respectively. However, the parasites collected during October 2005 had mutations associated with a lower level of pyrimethamine resistance and a higher level of sulfadoxine resistance (a rare combination), as well as a novel K540N mutation in P. falciparum dihydropteroate synthetase (PfDHPS). The emergence of this parasite population coincided with the widespread use of an additional antifolate drug, trimethoprim-sulfamethoxazole, to treat other infections during January- March 2005. Molecular modeling revealed that the sulfadoxine binding affinity of the new PfDHPS triple mutant A436G437N540A581A613 was similar to that of A436G437E540A581A613 (bold type indicates mutated amino acids). The use of 2 antifolate drugs in combination should be avoided to prevent the selection of parasites with newer mutations and altered drug susceptibilities

Genetic variability of diurnally sub-periodic Wuchereria bancrofti in Nicobarese tribe of Nicobar group of Islands, Andaman and Nicobar Islands, India

Sub-periodic form of Wuchereria bancrofti occurs in several well-isolated islands of Nicobar group of islands of Andaman Nicobar archipelago, India, presenting an interesting situation to study the genetic variability of its population. Microfilariae collected from 40 microfilaria (mf) carriers residing in eight locations on five islands (five carriers from each locality) were studied for genetic variability by generating random-amplified polymorphic DNA profiles. Phylognetic analysis of the profiles revealed a considerable genetic variability among parasite populations of different islands. The Nei's gene diversity between populations of 40 individual mf carriers ranged from 0.0218 to 0.2400. It was highest (0.24) among the parasite populations of Car Nicobar island and lowest (0.0218) among those of Payuha area of Camorta island and Teressa island. The dendrogram constructed exhibited four distinct clusters, which are geographically localized, and the gene flow between them appears to be influenced by human migration pattern.

Observations of Run-up and Inundation Levels from the Teletsunami in the Andaman and Nicobar Islands: A Field Report

In this study, we aimed to document the run-up and inundation of recent tsunamis and loss of life in the December 26, 2004, tsunami in the Andaman and Nicobar Islands. An estimated 1925 people lost their lives and 5555 were reported missing in the Andaman and Nicobar Islands because of the tsunami. The Nicobar group of Islands—namely Great Nicobar, Katchall, Teressa, Nancowry, Trinkat, Car Nicobar, and others—were severely affected by tsunami because they were close to the epicentre. The effect on the Andaman Islands was less severe because of the island's geometry and topography. Because the settlements in the South Andaman Islands are largely confined to sheltered areas like bays that are far from the coast, and more importantly, in elevated areas (except for certain low-elevation, far inland locations like the Sippighat area) there was almost no loss of life. However, damage to property, especially fishing vessels, was high in most of the area, where seawater inundated the land completely. This field survey was conducted at 26 sites; the Little Andaman passenger jetty area recorded the highest run-up of 17.26 m, and the Chidiyatopu area had the highest inundation at 500 m. Furthermore, this survey also supports the assertion that the low-lying areas of Little Andaman were severely affected by the tsunami waves because of their gradual elevation increase.

Outbreak of rotaviral diarrhoea in a relief camp for tsunami victims at Car Nicobar Island, India

The Andaman and Nicobar Islands a Union Territory of India is a stretch of more than 300 islands in the Bay of Bengal. The Asian tsunami of December 2004 severely affected the islands particularly Car Nicobar an island inhabited predominantly by Nicobarese tribes. Several hundred people were killed and thousands went missing. All the 17 villages in the island located along the coast were destroyed. The survivors fled interior into the jungles and settled there in temporary camps. The largest settlement that of Mus village remained cut off from the remaining camps for several days after the tsunami. Our team visited Mus on 11 January 2005 after a jungle track was cleared and found a large number of patients suffering from diarrhoea. As per the records kept at a makeshift medical camp manned by local paramedics cases of diarrhoea had been increasing since 7 January 2005. There were 1346 inmates (654 males and 692 females) at the camp. From 7 to 29 January a total of 113 cases of diarrhoea were reported giving an attack rate of 8.4%. Attack rate was 100% among infants and it showed a decline with increasing age the only exception being a higher attack rate among those aged 10-14 years compared to those in the age group of 5-9 years. There was one death giving a case fatality ratio of 0.88%. The epidemic curve showed a sharp increase from 7 January and a slow decline after 15 January with multiple peaks indicating secondary cases. No bacterial enteric pathogen was isolated from any of the stool samples collected from the patients. Group A rotavirus was found by RNA electrophoresis in 19 out of 20 samples tested. Drinking water samples from five of the six wells supplying water to the camp showed contamination by coliforms. Chlorination of the water sources was started immediately and samples were tested daily for residual chlorine. Halogen tablets were distributed and the people were motivated to use boiled water for drinking. Later pit-latrines were constructed near the camp. Attack rates among people using different wells ranged from 0 to 15%. People using the water of five of the six wells were affected indicating that either all these wells were contaminated or the source of infection was not well water. Once daily chlorination of wells was started the number of cases started decreasing. No other specific cause could be identified as the source of infection. Although epidemics of rotaviral diarrhoea are common in some countries it is rare in institutional settings or camps. The inaccessibility of the Mus village camp immediately after the tsunami delayed institution of preventive measures against water-borne diseases and by the time access was made the outbreak had begun. Apparently the water sources which were not commonly in use before the disaster were contaminated and open defecation practiced before construction of pit-latrines aided transmission of infection. Institution of public health intervention measures not only contained the current outbreak but might have also prevented an imminent threat from cholera that occurred in the neighbouring Nancowry islands in 2002. (excerpt)

Effect of the M 9.3 Sumatra–Andaman islands earthquake of 26 December 2004 at several permanent and campaign GPS stations in the Indian continent

The effect of the 26 December 2004 Sumatra–Andaman earthquake on the Indian continent has been estimated from the analysis of GPS data from permanent and campaign GPS sites in the Indian continent. Co‐seismic displacements at these sites have been determined for 11 permanent GPS stations of the national network, five campaign sites in southern India, and four campaign sites in Andaman and Nicobar Islands. The results indicate co‐seismic eastward displacements of 12–20 mm in southern India almost directly west of Andaman, 1.8–6 mm in Central India and insignificant displacement in the Himalayas. Permanent sites in north‐east India which lie almost towards the northward extension of the rupture plane show smaller co‐seismic displacements ranging from 5 to 10 mm southward. Four campaign sites in the Andaman and Nicobar Islands show large horizontal co‐seismic displacements of 1.6–6.49 m WSW and SW. Vertical displacement varies from an uplift of 0.6 m in north Andaman to 1.1 m subsidence at Car Nicobar. The observed GPS displacements are modelled using coulomb 2.6, and the slip on the four segments of the rupture plane (450 km×175 km; 250 km×140 km; 250 km×100 km; 150 km×100 km) that best fits both the far and near field displacements is estimated to be predominantly 12 m reverse in the southernmost segment, which slowly translates to an oblique slip of 7 m in the northernmost segment of the rupture plane. The seismic moment of the Sumatra–Andaman earthquake for the above rupture plane and slip is M o = 5.21×1022 Nm, which corresponds to a moment magnitude of M w = 9.1.

Tsunami damage assessment: a case study in Car Nicobar Island, India

The present studies deal with the tsunami damage assessment of the 26 December 2004 tsunami that occurred as a result of an Indonesian earthquake (Mw9.3) on Car Nicobar Island. Remote Sensing and GIS techniques are used to identify and assess the damage caused by the tsunami. The IRS 1D LISS III (Pre) and IRS P‐6 (Post) satellite data are used in analysing the tsunami height, run‐up elevation, water‐flow direction, inundation distance, sand deposition, coastal response, subsidence and erosion hazards, and overall assessment of damage. In order to confirm the results of the analysis, an extensive field survey was conducted on the island. The analysis reveals that the tsunami height was 0.7–15 m on the beaches. The run‐up level was 2–19 m with an inundation distance of 295.87–1202.57 m from the shoreline. The sand deposits at Aukchung and Arong beaches were 2.5 m and 1.0 m, respectively. The coastal subsidence at Malacca beach was 0.75–1.12 m, with significant coastal modification at various places.

Seaweed floristic studies along tsunami affected Indian coasts: A litmus test scenario after 26th December 2004

On 26th December 2004, the world witnessed the devastating power of tsunami, affecting many countries, bordering the Indian Ocean region. This has caused significant changes in the shallow and intertidal regions of the Indian coast, especially the Andaman and Nicobar Islands, Tamil Nadu, Kerala and Pondicherry. The baseline data on biomass availability and distribution of benthic intertidal seaweed species were collected immediately after this catastrophic event by spot surveying 11 selected localities of the above-mentioned regions. In all, 45 species belonging to 31 genera were recorded during the present survey, the maximum number of seaweed species were recorded at Thirumullavarum, Kerala with the minimum at Car Nicobar, Andaman and Nicobar Islands. A very different trend was observed in the case of biomass availability at some locations which was due to the influence of habitat suitability over the tsunami damage. The details of this study have been provided in the present communication

Quadruple Mutations in Dihydrofolate Reductase of Plasmodium falciparum Isolates from Car Nicobar Island, India

Quadruple mutations in the Plasmodium falciparum dihydrofolate reductase (PFDHFR) enzyme give rise to the highest level of pyrimethamine resistance leading to treatment failures. We describe here the presence of these quadruple mutations in a majority of P. falciparum isolates from Car Nicobar (Andaman and Nicobar) Island, India. Isolates from the mainland, however, continue to show a prevalence of double PFDHFR mutations and some with triple but none with quadruple mutations. In conclusion, the antifolate drug pressure is very high in the island, which should be a cause of concern for the malaria control program in the country.

Homegardens of Andaman and Nicobar, India

The study reports the influence of biophysical and socio-cultural factors on composition, diversity and distribution of plant species in the homegardens of the Andaman and Nicobar archipelago of India. The study also examines component interactions and productivity of the system. Four hundred and thirty homegardens were surveyed from six islands, four from Andaman (South Andaman, North Andaman, Middle Andaman and Little Andaman) and two from Nicobar district (Car Nicobar and Nancowry). In Nicobar, an aboriginal tribe, the Nicobari, predominates. The Nicobaries are Christians. However, people from different parts of the Indian subcontinent were rehabilitated in the Andamans in the mid twentieth century. A mixed culture prevails in South Andaman, but in the other Andaman islands either Bengali or Tamil culture predominates. Biophysically, South Andaman is hilly whereas Nicobar is flat. The other islands lie in between the two extremes. All are similar climatically. Twelve to thirty-four plant species were encountered in the homegardens that were planted, cared for and harvested. These plants categorized as palm, fruit, spice and forest trees, formed a three-storey structure in Andaman and a two-storey structure in Nicobar’s homegardens. The floristic similarity between the homegardens of the Andamans was 82–92%. However, it was only 12–18% between the homegardens of Andaman and Nicobar. Compared to Nicobar, species richness was greater in the homegardens of the Andamans. However, diversity was higher and evenness lower in the homegardens of Nicobar. All plant species in the homegardens of Nicobar are spontaneous in regeneration. For the Andamans, the proportion of spice trees was higher in the homegardens of South Andaman, mango and citrus in North Andaman, and pineapple and vegetables in Little Andaman. High plant diversity in these homegardens serves subsistence needs and provides income to most of the households as well. Net income in the homegardens of Andaman was 6.9 times higher compared to that in the homegardens of Nicobar.

Rupture process of the 2004 great Sumatra-Andaman earthquake estimated from tsunami waveforms

Abstract Rupture process of the 2004 Sumatra-Andaman earthquake is estimated using tsunami waveforms observed at tide gauges and the coseismic vertical deformation observed along the coast. The average rupture speed of the 2004 Sumatra-Andaman earthquake is estimated to be 1.7 km/s from tsunami waveform analysis. The rupture extends about 1200 km toward north-northwest along the Andaman trough. The largest slip of 23 m is estimated on the plate interface off the northwest coast in the Aceh province in Sumatra. Another large slip of 21 m is also estimated on the plate interface beneath the north of Simeulue Island in Indonesia. The other large slip of 10–15 m is estimated on the plate interface near Little Andaman and Car Nicobar Inlands. The total seismic moment is calculated to be 7.2 × 1022 Nm (Mw 9.2) which is similar to the other studies using seismic waves (Park et al., 2005; Ammon et al., 2005).

Biodiversity of Plant and Soil Nematodes from Andaman and Car Nicobar Islands

Biodiversity of Plant and Soil Nematodes from Andaman and Car Nicobar Islands

Molecular identification of Anopheles ( Cellia) sundaicus from the Andaman and Nicobar islands of India

Anopheles ( Cellia) sundaicus (Rodenwaldt) is an important malaria vector in the Andaman and Nicobar islands of India where it breeds in freshwater as well as in brackish water. To establish the molecular identity of An. sundaicus on these islands we analyzed samples from four geographically isolated areas—Teressa, Nancowry, Car Nicobar and Katchal islands. PCR-amplification and nucleotide sequence analysis were performed for internal transcribed spacer 2 (ITS2) and domain-3 (D3) of 28S rRNA. The ITS2 region of An. sundaicus from all four islands was identical but different from An. sundaicus A of Vietnam and An. sundaicus s.s of Malaysia. Furthermore, freshwater and brackish water forms of An. sundaicus did not reveal any sequence variation. Similarly, the D3 sequences were identical among all An. sundaicus samples from the four islands. D3 sequences for a species of the Sundaicus Complex are reported here for the first time and thus could not be compared with other regional isolates of this species. In conclusion, probably only one member of the Sundaicus Complex exists on the Andaman and Nicobar islands, which breeds in freshwater as well as in brackish water and is different from the An. sundaicus A and Malaysian An. sundaicus s.s. The identification of a new sibling species of the Sundaicus Complex in these islands is significant from the viewpoint of vector control strategies.

Tsunamis

On 26 December 2004, at about 9 am, many parts of the east coast of India experienced sudden changes in water level. As the waters rose, they moved inland with a ferocity unusual to the region to flatten structures that stood in their way. Fifteen to twenty minutes later, the waters receded, only to rise again some time later. Similar variation in sea level was noticed at different times and with different intensities at other coastal locations of the country: Car Nicobar in the Nicobar Islands, Port Blair in the Andaman Islands, along the southwest coast of India, etc. Similar behaviour was also noticed in parts of other south Asian countries: Sumatra in Indonesia, Thailand, Myanmar, Sri Lanka, and the Maldives.

Nicobari Tribe of the Car Nicobar Island: Keeping in Pace with Time

Tropical rain forests worldwide are home to millions of tribal population belonging to diverse communities. During last few decades population pressure and migration of settlers in tribal areas for developmental needs have currently threaten the existence of the aboriginals. Most of the ethnobotanical knowledge in India is concentrated in remote tribal areas. The use of plant species in sustainably with nature lies hidden with native people, living in vicinity with nature.

Incidence of Colour Blindness Among the Nicobarese of Car Nicobar

Since each colour blind man is hemizygous for the mutant allele, the frequency of the allele comes to be 0.028 and the frequency of the normal allele to be 0.972.