59 results on '"C. Venkatraman"'
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2. Durga Das’s Leaf-nosed Bat Hipposideros durgadasi Khajuria, 1970 (Mammalia: Chiroptera: Hipposideridae): a new distribution record in northern India hidden in the National Zoological Collections
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M. Kamalakannan, Tauseef Hamid Dar, and C. Venkatraman
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chiroptera ,durga das’s leaf-nosed bat ,hipposideros durgadasi ,national zoological collections ,new record ,northern india. ,Ecology ,QH540-549.5 ,General. Including nature conservation, geographical distribution ,QH1-199.5 - Abstract
Durga Das’s leaf-nosed bat Hipposideros durgadasi Khajuria, 1970 is one of the endemic bats in India and was known only from Jabalpur district of Madhya Pradesh and Kolar district of Karnataka. Upon careful examination of the external morphology, craniodental and baculum structure of the bat collections, which were collected from 14 km west of Mirzapur district of Uttar Pradesh, northern India during the year 1998 and deposited in the National Zoological Collections of Zoological Survey of India were identified as Hipposideros durgadasi. It is the first report on the occurrence of Durga Das’s leaf-nosed bat in Uttar Pradesh and an additional distribution record in northern India.
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- 2018
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3. An old collection reveals an additional distribution record of the Greater Long-tongued Fruit Bat Macroglossus sobrinus K. Anderson, 1911 (Chiroptera: Pteropodidae) from southern West Bengal, India
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Tauseef Hamid Dar, M. Kamalakannan, C. Venkatraman, and Kailash Chandra
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greater long-tongued fruit bat ,macroglossus sobrinus ,narendrapur ,national zoological collections ,Ecology ,QH540-549.5 ,General. Including nature conservation, geographical distribution ,QH1-199.5 - Abstract
Greater Long-tongued Fruit Bat Macroglossus sobrinus K Anderson, 1911 is one of the small fruit bat found in South and Southeast Asia. In India, this species has only been reported from northern West Bengal, Sikkim and Northeast India. Upon detailed examination of the external morphology, skull and dentition of a single bat specimen, which was collected from Narendrapur, South 24- Parganas district in West Bengal (southern West Bengal) during the year 1995 and deposited in the National Zoological Collections of Zoological Survey of India, was identified as Macroglossus sobrinus. It is the first report on the occurrence of the species from southern West Bengal, extended distribution by more than 600 km southward from the known localities in Darjeeling in northern West Bengal.
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- 2018
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4. New records of cheilostome Bryozoa from the eastern coast of India encrusting on the exoskeleton of live horseshoe crabs of Indian Sundarbans
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Maria Susan Sanjay, Swati Das, Basudev Tripathy, K. A. Subramanian, and C. Venkatraman
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Fishery ,Geography ,biology ,Bryozoa ,Animal Science and Zoology ,Management, Monitoring, Policy and Law ,biology.organism_classification ,Ecology, Evolution, Behavior and Systematics ,Nature and Landscape Conservation ,Exoskeleton ,Horseshoe crab - Abstract
Bryozoans are common commensal on hard surfaces and cover slow-moving animals like molluscans, sea turtles, brachyuran crabs, and horseshoe crabs. A total of six species of bryozoans belonging to four genus under three families of order Cheilostomatida were recorded encrusting on the carapaces of horseshoe crabs collected from Indian Sundarbans along the east coast of India and two among them, viz., Biflustra savartii (Audouin, 1826) and Sinoflustra arabianensis (Menon & Nair, 1975) are reported for the first time. Additionally, Jellyella tuberculata (Bosc, 1802) is reported for the first time from West Bengal coastal waters, previously known only from the Odisha coast of India. Both male and female horseshoe crabs were found to have been encrusted with bryozoan mats, although adequately not known about the life stages of their encrustation.
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- 2021
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5. Diversity and distribution of scleractinian corals from Mandapam group of Islands in Gulf of Mannar marine national park, South East coast of India
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S. Geetha, C. Venkatraman, J. S. Yogesh Kumar, and Chelladurai Raghunathan
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Fishery ,Geography ,geography.geographical_feature_category ,business.industry ,National park ,Coral ,Species distribution ,Period (geology) ,Distribution (economics) ,Coral reef ,business ,Reef ,Correspondence analysis - Abstract
The Mandapam group of Islands being a part of the Gulf of Mannar Marine National Park shows a variety of marine biodiversity in each of the seven Islands. A Scleractinian coral shows a rich diversity in the study islands during the study period. The present study will help us to get a summarized species distribution in the Mandapam group of Islands. The maximum percentage of hard coral cover was recorded in the Poomarichan Island followed by Single Island, Manoliputti Island, Manoli Island, Hare Island, Kurusadai Island and Pullivasal Island. A total of 69 species of scleractinian corals were listed from the coral reef Islands in the study sites of Mandapam group. Statistical analysis such as Principal Component Analysis and Correspondence Analysis supported the status of maximum coral cover in Poomarichan Island.
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- 2021
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6. First Camera Trap Record of Fishing Cat Prionailurus viverrinus Bennett, 1833 (Carnivora: Felidae) from a Rural Wetland of Mid-West Bengal, India
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Ranjana Saha, Samrat Chakraborty, Goutam Kumar Saha, Souvik Barik, Subhendu Mazumdar, C. Venkatraman, Kaushik Deuti, and Ajanta Dey
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education.field_of_study ,biology ,Felis ,Immunology ,Jungle cat ,Population ,Fishing ,Cell Biology ,Aquatic Science ,biology.organism_classification ,Prionailurus viverrinus ,Fishery ,Endocrinology ,Geography ,Insect Science ,Jackal ,biology.animal ,Genetics ,Camera trap ,Canis aureus ,Animal Science and Zoology ,education ,Ecology, Evolution, Behavior and Systematics - Abstract
Prionailurus viverrinus, a wetland-dependent lesser cat with globally declining population, is suffering from increasing destruction/conversion of wetlands for various anthropogenic use, poaching, retaliatory killing etc. In India, they prefer to thrive in dense emergent vegetation adjoining different wetlands along the east coast and Gangetic plains. However, surveys determining their distribution range were carried out long ago and, due to various threats they have been decimated from many areas where they used to thrive earlier. This demands for a reassessment of their present status across its reported distribution range. Here we report the presence of fishing cats (through camera trap evidence) for the first time from a human-dominated wetland habitat of Murshidabad district, West Bengal, India. Out of all camera-trap images in the present study (N = 39), majority are of fishing cats Prionailurus viverrinus (25 pictures, 64.10%) followed by golden jackal Canis aureus (12 pictures, 30.76%), and jungle cat Felis chaus (two pictures, 5.12%). None of these wild fauna were recorded during day time. Fishing cats and golden jackals were mostly recorded between 21:01–3:00 h and 18:00–21:00 h respectively. Two images of jungle cats were also captured, one each during 21:01–00:00 h and 00:01–3:00 h. Similar studies in other wetlands within the distributional range of fishing cats will collectively validate their present distribution, which might be useful for in-situ conservation of this elusive vulnerable species.
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- 2020
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7. Seasonal Variation of Physico-Chemical Parameters and Their Influence on Phytoplankton Community of Muthupet Estuary, Southeast Coast, Tamil Nadu, India
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B. Bharath, C. Venkatraman, K. Perinbam, and A. Suganthi
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geography ,geography.geographical_feature_category ,Estuary ,General Medicine ,Seasonality ,medicine.disease ,Monsoon ,Salinity ,Diversity index ,Nutrient ,Oceanography ,Phytoplankton ,medicine ,Environmental science ,Species evenness - Abstract
Physico-chemical parameters of freshwater are most important factor for diversity and density of phytoplankton community. Hence, the present study was intended to evaluate the seasonal variation on physico-chemical parameters such as rainfall, temperature, pH, salinity, dissolved oxygen and their relationship with phytoplankton community of Muthupet estuary. The seasonal variation of nutrients like nitrate, phosphate and silicate was recorded to determine the utilization of nutrients by phytoplanktons in aquatic environment. The results exposed that physico-chemical parameters showed significant difference among the seasons. The nutrient dynamic of Muthupet estuary exhibits considerable seasonal variation due to the rainfall and nutrient utilization of autotrophs. There are totally 14 species of phytoplankton under three different groups namely Bacillariophyceae, Dinophyceae and Cyanophyceae was recorded. The highest phytoplankton density was recorded during summer season (18541.67b ± 3934.52/m3), while lower in monsoon seasons. The statistical analysis of physico-chemical parameters showed significant variation among seasons and the diversity indices of phytoplankton were high during post monsoon for both Simpson and Shannon indices and also on Evenness. The correlation analysis exposed that physico-chemical parameters and nutrients are effective dynamics to control the seasonal variations on phytoplankton diversity. Therefore, the present study reveals that Muthupet estuary has rich in phytoplankton community due to presence of high nutrient content and consisting of appropriate environmental factors.
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- 2020
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8. Camera-trap records of fishing cat (Prionailurus viverrinus) from East Medinipur (West Bengal, India), and notes on threats to this population
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Ajanta Dey, Samrat Chakraborty, Souvik Barik, Goutam Kumar Saha, Kaushik Deuti, Subhendu Mazumdar, C. Venkatraman, and Ranjana Saha
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0106 biological sciences ,geography ,education.field_of_study ,geography.geographical_feature_category ,Ecology ,biology ,Fishing ,Population ,Wetland ,Prionailurus viverrinus ,biology.organism_classification ,01 natural sciences ,010601 ecology ,Fishery ,Habitat ,IUCN Red List ,Camera trap ,West bengal ,education ,Ecology, Evolution, Behavior and Systematics - Abstract
The fishing cat (Prionailurus viverrinus) is a medium-sized felid, which uses various habitats including areas adjoining wetlands. This species is listed as ‘vulnerable’ in the IUCN Red List 2016, ...
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- 2020
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9. Influence of physio-chemical parameters on fish diversity in Muthupet estuary, Southeast Coast of India
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C. Venkatraman, K. Perinbam, A. Suganthi, and B. Bharath
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Fishery ,geography ,geography.geographical_feature_category ,media_common.quotation_subject ,%22">Fish ,Estuary ,Biology ,Diversity (politics) ,media_common - Published
- 2018
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10. First record of a Nicobar treeshrew nest in a fallen palm tree
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Kamalakannan, Manokaran, primary, G., Gokulakrishnan, additional, C., Venkatraman, additional, C., Sivaperuman, additional, and Chandra, Kailash, additional
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- 2020
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11. Seasonal Variation of Physico-Chemical Parameters and Their Influence on Phytoplankton Community of Muthupet Estuary, Southeast Coast, Tamil Nadu, India
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A., Suganthi, primary, C., Venkatraman, additional, B., Bharath, additional, and K., Perinbam, additional
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- 2020
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12. Coral associated bryozoans and their role in reviving the depleting coral ecosystem
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C. Venkatraman, Maria Susan Sanjay, R. Babu, Soja Louis, and S. Shrinivaasu
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0106 biological sciences ,Pioneer species ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Ecology ,010604 marine biology & hydrobiology ,Coral ,Rubble ,Ecological succession ,Coral reef ,Aquatic Science ,engineering.material ,01 natural sciences ,Ecosystem services ,Geography ,Habitat ,engineering ,Animal Science and Zoology ,Ecosystem ,Ecology, Evolution, Behavior and Systematics ,0105 earth and related environmental sciences - Abstract
Coral reefs are one of the important habitats of marine biodiversity in shallow tropical waters as they sustain numerous crucial ecosystem services. This study provides the taxonomic account and sheds light on the habitat of Bryozoan species, which exclusively considers corals as its substratum for their growth and their role in reviving the depleting coral ecosystem. The systematic description of 12 coral associated bryozoans is, discussed here. Among the described 12 species, six of them, Parasmittina collifera (Robertson, 1908), Smittipora philippinensis (Canu and Bassler, 1929), Onychocella angulosa (Reuss, 1848), Plesiocleidochasma porcellanum (Busk, 1860), Robertsonidra argentea (Hincks, 1881) and Schizoporella errata (Waters, 1878) are reported for the first time in Indian waters. The survey was conducted during April 2013–April 2015 in Gulf of Mannar Marine Biosphere Reserve (GoMBR). Bryozoan species were, collected from the coral rubble and coral skeletal framework in the shallow waters (up to 5 m) and illustrated by scanning electron microscopy (SEM). A conclusion was drawn from this study, where Bryozoans, which colonise dead coral skeletal framework and rubble, can revive the depleting coral reef ecosystem as they play a major role in cementation and act as pioneer species in succession.
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- 2021
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13. An Update on the Mammals of Western Ghats
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C. Venkatraman, Debashree Dam, and M. Kamalakannan
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Geography ,Habitat destruction ,biology ,Ecology ,Fauna ,Livestock grazing ,biology.animal ,parasitic diseases ,Logging ,Endangered species ,Poaching ,Vertebrate ,Class Mammalia - Abstract
Western Ghats (WG) is one of the 35 hotspots of the world and home to several endemic and endangered vertebrate fauna. The mammalian fauna of Western Ghats includes 133 species representing 10 orders and 31 families of class Mammalia, which is about 31% of the total Indian mammalian fauna. Twenty-six species of endemic mammals were reported from the Western Ghats, out of 44 species of endemic mammals known from the different regions of India. The habitat loss and degradation due to industrial activities, human encroachment, poaching, livestock grazing, man-wildlife conflict, plantations and logging are considered as major threats.
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- 2018
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14. A formal comparison of formal protocol specification techniques.
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R. C. Venkatraman and Thomas F. Piatkowski
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- 1985
15. Nest-site selection by colonical waterbirds at Vedanthangal Waterbird Sanctuary, Tamil Nadu, India
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C. Venkatraman
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Fishery ,Geography ,Tamil ,language ,Forestry ,Nest site ,Selection (genetic algorithm) ,language.human_language - Published
- 2007
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16. Coastal and Marine Bird Communities of India
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C. Venkatraman and C. Sivaperuman
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Charadriiformes ,East coast ,Geography ,geography.geographical_feature_category ,biology ,Ecology ,Threatened species ,Dominance (ecology) ,Wetland ,West coast ,biology.organism_classification ,Falconiformes ,Global biodiversity - Abstract
A total of 223 species of birds were recorded from the coastal wetlands of India, belonging to 30 families under 9 orders. The highest number of species was recorded from the east coast, followed by the west coast, and the Andaman and Nicobar Islands. The order Charadriiformes was highest in dominance, followed by Falconiformes and Ciconiiformes. Thirty one threatened bird species were recorded from the coastal wetlands. There is a need to protect coastal and marine areas with high priority conservation for future research on bird communities.
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- 2015
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17. Seasonal Abundance of Sea Snakes on the Chennai Coast, Southern India
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P. Padmanaban, Chandrakasan Sivaperuman, and C. Venkatraman
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Fishery ,Geography ,Hydrophis spiralis ,biology ,Common species ,Fishing ,Hydrophis ornatus ,Enhydrina schistosa ,biology.organism_classification ,Incidental catch ,Snout ,Lapemis curtus - Abstract
This chapter highlights the incidental catch of sea snakes collected from the Chennai coast, southern India during 2009–13. Of the 12 species reported from previous studies, 10 species were caught incidentally by various types of fishing gear. Hydrophis ornatus was recorded for the first time on the Chennai coast. Enhydrina schistosa seems to be the most common species, and Pelamis platurus and Lapemis curtus are rare. There was a strong correlation between snout to vent length (SVL) and weight, and between total length and weight, in the cases of Enhydrina schistosa and Hydrophis spiralis .
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- 2015
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18. Diversity and Distribution of Sea Grass Associated Macrofauna in Gulf of Mannar Biosphere Reserve, Southern India
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R. Rajkumar, S. Shrinivaasu, K. Venkataraman, K. Paramasivam, and C. Venkatraman
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Cnidaria ,Fishery ,Ecology ,Abundance (ecology) ,Species distribution ,Biosphere ,Species diversity ,Ecosystem ,Species richness ,Biology ,biology.organism_classification ,Mollusca - Abstract
The diversity, distribution, occurrence and abundance of sea grass associated macrofauna were studied in the Mandapam group of Islands of the Gulf of Mannar Biosphere Reserve (GOMBR) during January to April 2012. A total of 150 species of macrofauna under the five groups Cnidaria, Crustacea, Mollusca, Echinodermata and Pisces were encountered. Of these, Mollusca and Pisces were predominantly found in the sea grass ecosystem of the Gulf of Mannar. The diversity of fishes was high in all islands during the study period. In general, the diversity, abundance and species richness were high in Manoli and Manoliputti Islands of GOMBR.
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- 2015
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19. Contributors
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D. Adhavan, S. Ajmal Khan, G. Ananthan, D. Apte, T. Balasubramanian, R. Balasubramanian, R. Baskaran, I.K. Chaaithanya, K. Devi, S. Geetha, K.C. Gopi, V.S. Gowri, T. Immanuel, A. Joseph, K. Kathiresan, P. Krishnan, A. Kulkarni, N.P. Kumar, P. Lakshmi Devi, B. Malakar, M. Mankeshwar, J.K. Mishra, A. Mishra, S.S. Mishra, P.M. Mohan, S. Mohamed Hussain, R. Mohanraju, S.K. Mohanty, A. Mohapatra, A.K. Mukhopadhyay, N. Muruganandam, P. Nammalwar, P. Padmanaban, K. Paramasivam, C. Raghunathan, R. Rajkumar, P.T. Rajan, D. Ray, V. Sachithanandam, K. Sadhukhan, A. Selva Prabhu, S. Kumar Shah, S. Shrinivaasu, J. Sinduja, C. Sivaperuman, B. Tripathy, P. Tudu, N. Veerappan, K. Venkataraman, C. Venkatraman, S. Venu, R. Vijayakumar, null Yasmin, P. Yennawar, and J.S. Yogesh Kumar
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- 2015
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20. Triple ladder approach - A novel noninvasive method of assessment of shunt responsiveness in normal pressure hydrocephalus
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T.P. Arulnambi, A.V. Srinivasan, A.S. Mulanur murugesan, C. Venkatraman, B. Peter, H. Jayakumar, and Lakshmi Narasimhan Ranganathan
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medicine.medical_specialty ,Neurology ,business.industry ,Normal pressure hydrocephalus ,Internal medicine ,Cardiology ,Medicine ,Neurology (clinical) ,business ,medicine.disease ,Shunt (electrical) - Published
- 2017
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21. Mercurial channel disease – A new entity
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F.E.I. Shaik, K. Kuppusamy, B. Kesavamurthy, C. Venkatraman, B. Samivel, H. Jayakumar, and Lakshmi Narasimhan Ranganathan
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Neurology ,business.industry ,Computer science ,Neurology (clinical) ,Channel (broadcasting) ,business ,Computer network - Published
- 2017
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22. Tribological properties of diamond-like nanocomposite coatings at high temperatures
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R. Lei, C. Venkatraman, and C. Brodbeck
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Materials science ,Nanocomposite ,Silicon ,Synthetic diamond ,Material properties of diamond ,chemistry.chemical_element ,Surfaces and Interfaces ,General Chemistry ,Condensed Matter Physics ,Surfaces, Coatings and Films ,law.invention ,Amorphous solid ,chemistry ,law ,Materials Chemistry ,Thermal stability ,Diamond cubic ,Thin film ,Composite material - Abstract
Diamond-like nanocomposites (DLN) films are amorphous and consist of C, H, Si, and O. In addition, metal atoms can be incorporated into the coatings. The DLN coatings exhibit a low coefficient of friction, low wear rate, low stress, high hardness and good adhesion on a variety of substrates. The thermal stability of DLN films deposited on silicon substrates was investigated after the samples had been thermally annealed in air and argon atmospheres. The sample analysis by micro-Raman spectroscopy, nano-indentation and ball-on-disk tribometry are reported here. The investigation revealed that the performance of DLN films from a tribological perspective is very good up to 400°C in air. The hardness of the DLN films showed a decrease of less than 15% up to 400°C in air. The wear rate of the DLN films was at or below 10 −7 mm 3 /Nm up to 400°C in air.
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- 1999
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23. Electrical properties of diamond-like nanocomposite coatings
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R Lei, C Outten, D Kester, A Goel, and C Venkatraman
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Nanocomposite ,Materials science ,Silicon ,Material properties of diamond ,Metals and Alloys ,Analytical chemistry ,Electrical breakdown ,chemistry.chemical_element ,Surfaces and Interfaces ,Dielectric ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,symbols.namesake ,chemistry ,Electrical resistivity and conductivity ,Materials Chemistry ,symbols ,Composite material ,Fourier transform infrared spectroscopy ,Raman spectroscopy - Abstract
Diamond-like nanocomposite (DLN) films comprising of C, H, Si, O and metal atoms were deposited on metallized silicon substrates via an accelerated plasma approach. The films were investigated by Raman spectroscopy, Fourier transform infrared spectroscopy and Rutherford backscattering. The film resistivity, dielectric constant, electrical breakdown and current-voltage hysteresis characteristics were measured using metal-insulator-metal heterostructures. Results indicate that DLN film resistivities can be tailored over 16 orders of magnitude (10 14 –10 −2 Ω -cm). Current-voltage measurements yielded breakdown strengths larger than 10 6 V/cm. The dielectric constant of the films investigated ranges from 3 to 8. Capacitance-voltage characteristics and the effect of temperature cycling was also studied. The properties of electrical tailorability and diamond-like properties make DLN a suitable candidate for applications requiring both wear resistance and electrical tailorability.
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- 1997
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24. Diversity and Distribution of Echinoderms in Palk Bay and Gulf of Mannar Biosphere Reserve, Southern India
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Rajan Rajkumar, K. Paramasivam, S. Shrinivaasu, C. Venkatraman, Chandrakasan Sivaperuman, P. Padmanaban, and K. Venkataraman
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Fishery ,geography ,geography.geographical_feature_category ,Abundance (ecology) ,Ecology ,Species diversity ,Biosphere ,Ecosystem ,Species richness ,Coral reef ,Relative species abundance ,Bay ,Geology - Abstract
The diversity, distribution, occurrence and abundance of echinoderms were studied in Palk Bay and Gulf of Mannar Biosphere Reserve during April 2010 through May 2012. Standard prawn trawl net, modified with added sinkers/bobbins, was used to assess the echinoderms. A total swept area of 0.45204 km2 in Gulf of Mannar Biosphere Reserve (GoMBR) (47 trawls) and 0.23265 km2 in Palk Bay (30 trawls) was covered. Forty-seven species of echinoderms under 21 families were encountered during this survey. The species diversity, species abundance and species richness values were high in GoMBR and low in Palk Bay. The sea grass bed, sandy bottom and good coral reef cover, which might be the attracted for more species in GoMBR. Since most of the echinoderms are very closely associated with coral reef ecosystem either for food, shelter or reproduction, it is utmost important to save the coral reef ecosystem which in turn conserves the echinoderms.
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- 2013
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25. Orientation texture in YBa2Cu3O7−δ films synthesized from amorphous precursors
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G. L. Liedl and C. Venkatraman
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Materials science ,Fabrication ,Mineralogy ,Partial pressure ,Condensed Matter Physics ,Epitaxy ,Electronic, Optical and Magnetic Materials ,Amorphous solid ,Grain growth ,Chemical engineering ,Rapid thermal processing ,Materials Chemistry ,Electrical and Electronic Engineering ,Pyrolysis ,Group 2 organometallic chemistry - Abstract
The metalorganic decomposition technique was utilized in the fabrication of YBa2Cu3O7−δ films with preferred orientation on (100) MgO and (100) SrTiO3 substrates. The processing parameters such as film thickness, firing treatment, and substrate modifications were controlled to obtain a high degree of three-dimensional preferred growth in the films. Results indicate that three-dimensional film preferred growth diminishes with increasing film thickness. Preferential growth in YBa2Cu3O7−δ films is enhanced with increasing firing temperature and reduced oxygen partial pressure due to enhanced atom mobility. Epitaxial growth of YBa2Cu3O7−δ films has been achieved on both lattice mismatched (MgO) and on lattice matched (SrTiO3) substrates. Epitaxial growth is promoted by lattice matched substrates at lower film firing temperatures. An attempt is made to understand the development of YBa2Cu3O7−δ film preferential growth via the epitaxial grain growth mechanism.
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- 1994
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26. An open-systems approach to video on demand
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D. Skellern, Manu Thapar, David John Coggins, D. Pitt, C. Venkatraman, and Yee-Hsiang Chang
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Video production ,Multimedia ,Computer Networks and Communications ,business.industry ,Computer science ,Video server ,Video on demand ,Telecommunications service ,Base (topology) ,computer.software_genre ,Cable television ,Computer Science Applications ,Variety (cybernetics) ,Server ,Electrical and Electronic Engineering ,business ,Telecommunications ,computer - Abstract
Open systems will enable video servers and set-tops to provide different services in a variety of environments. Hewlett-Packard is interested in applying the principles of open systems to video on demand (VOD). In particular, the company is developing a technology base that will allow their servers and set-tops to operate in a variety of environments and enable the provision of a variety of services. The impact that the different VOD system elements have on the video server and set-top are examined from a communications standpoint. Opportunities for open or standard interfaces are identified and recommendations are made on what these should be where possible. >
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- 1994
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27. Structural and transport measurements inLa1.8Sr0.2NiO4+δ
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GL Liedl, SA Hoffman, SM Durbin, SN Ehrlich, and C Venkatraman
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Superconductivity ,Magnetization ,Paramagnetism ,Lattice constant ,Materials science ,Condensed matter physics ,Electrical resistivity and conductivity ,Remanence ,Diamagnetism ,Magnetic susceptibility - Abstract
Lattice constants, electrical resistivity, and magnetization have been measured as a function of temperature on single crystals of La{sub 1.8}Sr{sub 0.2}NiO{sub 4+{delta}}, a nickelate analog of lanthanum strontium cuprate, the 40-K superconductor. Diamagnetism was observed at 4.2 K, but not zero resistance. The oxygen concentration was carefully controlled to probe the region close to stoichiometric lanthanum strontium nickelate, from {delta}=0.001 to 0.003. The high-temperature tetragonal structure persists down to near 100 K, with semiconductorlike resistivity showing activation energies between 32 and 54 meV, depending on {delta}. Below 100 K the structure transforms into a low-temperature orthorhombic phase, often displaying distinct, cycling-dependent changes in activation energies. In some specimens the resistance occasionally fell by several orders of magnitude, but recovered to previous values within a few degrees. X-ray-diffraction rocking curves reveal striking changes in the mosaic spread of these specimens as a function of both time and temperature, which helps explain the irreproducibility of the activation energies and the resistance anomalies. Although no further structural changes are observed, the paramagnetic susceptibility goes through a maximum at 20 K. Consistent with previous reports, the magnetic remanence becomes finite below 20 K and the susceptibility decreases, sometimes becoming diamagnetic above 4.2 K. Themore » activation energy in this phase abruptly decreases to only 5 meV, while the resistivity exceeds 10{sup 10} {Omega} cm. No evidence of zero resistance was found.« less
- Published
- 1991
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28. A P2P-Based Architecture for Secure Software Delivery Using Volunteer Assistance
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C. Venkatraman, Jehan-Francois Paris, J. Schettino, Purvi Shah, and J. Morgan
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business.industry ,Computer science ,Distributed computing ,Workload ,computer.file_format ,Load balancing (computing) ,Synchronization ,Load management ,Software ,Server ,Scalability ,business ,BitTorrent ,computer ,Computer network - Abstract
We present a content delivery infrastructure distributing and maintaining software packages in a large organization. Our work is based on a trace-based analysis of an existing software delivery system that we conducted to find general principles and properties could be used to devise a better solution. Our design combines a conventional server with volunteer nodes that expand its scalability. We rely on Peer-to-Peer technology to speed up content synchronization among the volunteer nodes while maintaining a conventional client/server interface for the service customers. Finally our system includes a novel load balancing mechanism that considers both the synchronization workload and the customer-generated workload of the volunteer nodes. Our simulation results indicate that the feedback information currently available at the server/tracker of the P2P system offers enough information to ensure a fair load distribution among the peers.
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- 2008
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29. Diamond-like nanocomposite coatings for low-wear and low-friction applications in humid environments
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Dominique Neerinck, P Swab, D Bray, C Venkatraman, D Kester, Marc Sercu, A Goel, C. Halter, and Peter Persoone
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Materials science ,Nanocomposite ,Metals and Alloys ,chemistry.chemical_element ,Diamond ,Surfaces and Interfaces ,Tribology ,engineering.material ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Amorphous solid ,chemistry ,X-ray photoelectron spectroscopy ,Materials Chemistry ,engineering ,Relative humidity ,Composite material ,Carbon ,Tribometer - Abstract
Diamond-Like Nanocomposite (DLN, Dylyn®) coatings are amorphous, hard and wear resistant coatings, deposited using a plasma-assisted CVD process. These coatings consist of two interpenetrating networks, one being a diamond-like carbon (a-C:H) network and the other a glass-like a-Si:O network. This specific structure leads to lower internal stress, better adhesion and higher temperature stability as compared to diamond-like carbon. The structure and bonding type were investigated using grazing-incidence X-ray diffraction (GIXRD) and X-ray photoelectron spectroscopy (XPS), respectively. The coefficient of friction of Diamond-Like Nanocomposites, as measured in a standard ball-on-disk tribometer using a steel counterbody, is typically 0.04 to 0.08 in air of 50% relative humidity (RH). Even in humid air of 90% RH and under water, the coefficient of friction stays below 0.1. The wear factor of Diamond-Like Nanocomposite coatings was determined using profilometric measurements of the wear track after a ball-on-disk test and is typically 2 x 10 -7 mm 3 /N m. Under water, an extremely low wear factor, below 5 x 10 -8 mm 3 /N m, was measured. This low-friction and low-wear behaviour of Diamond-Like Nanocomposite coatings, also in humid environments, enables industrial applications of these coatings as hard, self-lubricating coatings on sliding parts in the automotive, chemical, pharmaceutical or biomedical industry.
- Published
- 1998
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30. CATV trends and video dialtone-technologies and challenges
- Author
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C. Venkatraman
- Subjects
Multimedia ,Order (exchange) ,Computer science ,Interactive video ,business.industry ,User interface ,Network topology ,Telecommunications ,business ,computer.software_genre ,Interactive television ,Cable television ,computer - Abstract
The cable television network infrastructure and the CATV market in the United States are undergoing a major technological change. Opportunities for interactive television and multimedia to every home seem more real than ever. The ability for the new cable network, in the form of fiber-coax combination, to provide wide bandwidth will make possible new applications. Application of this type are movies-on-demand, interactive newspaper, networked libraries, interactive home shopping, etc. In order to provide cost effective implementations, a number of technology barriers must be overcome. These applications stress every aspect of communication, computation, network, and user-interface technology we know of today. We address the technology and the challenges to make these applications work. This intricate, expensive technology and infrastructure require cooperation between a number of industry partners and network providers. This demands a need for standards covering protocols and interfaces; one common framework is video dialtone. The technical aspects of video dialtone are discussed from a signalling point of view. >
- Published
- 2002
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31. Diamond-like nanocomposite coatings possessing high dielectric strength
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B.F. Dorfman, T.G. Engel, C. Venkatraman, A. Goel, N.G. Loter, and M. Abraizov
- Subjects
Materials science ,Nanocomposite ,Dielectric strength ,Arc flash ,Electronic engineering ,engineering ,Diamond ,Insulator (electricity) ,Dielectric ,engineering.material ,Thin film ,Composite material ,Microwave - Abstract
Insulator failure, due to flashover or dielectric breakdown, is the cause of decreased system reliability and component lifetime in many plasma and microwave devices. Radiation effects, including ultraviolet radiation and ion-bombardment often accelerate insulator deterioration. Replacement of plastic insulators with ceramic insulators is not practical in many cases. We have studied the feasibility of utilizing the novel diamond-like nanocomposite (DLN) thin films to protect plastic insulators and extend lifetime by enhancing dielectric properties and flashover resistance. Very high dielectric strength (10/sup 7/-10/sup 8/ V/cm), and high flashover resistance at various pressures have been measured. The mechanisms of breakdown are currently under investigation. Applications exist in diverse areas including power transmission, slip rings, ultracapacitors, plasma switch technology, nuclear simulators and X-ray sources (e.g., Z-pinch devices).
- Published
- 2002
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32. Thermo-physiological Comfort Properties of Polyester and Polyester/Acrylic blended Synthetic Fabrics treated with Herbal Finishes
- Author
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Periyasamy Sidhan, Gunasekaran Govindachetty, and Koushik C. Venkatraman
- Subjects
Polyester ,SILK ,Materials science ,Moisture ,Wool ,Water vapor permeability ,General Materials Science ,Moisture management ,Composite material - Abstract
Thermo-physiological comfort in clothing mainly lies in moisture management, which often refers to the transport of both moisture vapor and liquid away from the body. Moisture management of fabrics is chiefly influenced by the thermal properties of those fabrics. In spite of the convincing properties that synthetic fabrics have, they are not much preferred because of their hydrophobic nature which provides less comfort to the wearer compared to the natural fabrics like cotton, wool, and silk. Previous studies report that the herbal finishes, which are eco-friendly in nature, improve the anti-microbial and other medicinal properties but very little or no work has been carried out on the comfort aspect of these fabrics. This work reports a study of the influence of two ecofriendly herbal finishes, Neem and Bermuda grass, on the thermo-physiological comfort properties of synthetic fabrics used in clothing. The herbal finishes were applied on to 100% Polyester and 50/50 Polyester/Acrylic blended fabrics. Prior to the application of finishes, the fabrics were given a pretreatment to achieve a better penetration and durability of the finishes. The finished fabrics were tested for the thermo-physiological comfort properties of Wicking, Water vapor permeability, and Thermal conductivity and the results were analyzed. It was revealed that both the Neem and Bermuda grass natural finishes considerably improved the moisture related properties and moderately reduced the thermal conductivity characteristics of the above synthetic fabrics. Durability to washing was also tested and discussed.
- Published
- 2014
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33. Cochin Banded Sea Snake, Hydrophis ornatus (Gray, 1842): a new record for Chennai Coast, East Coast of India
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P. Padmanaban and C. Venkatraman
- Subjects
Fishery ,East coast ,Oceanography ,Geography ,biology ,Hydrophis ornatus ,biology.organism_classification ,Gray (horse) - Published
- 2009
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34. Laser Beam Lithography of Metal Oxide Electrodes for PZT Memory Applications
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Gerald L. Liedl, Arden Bement, Jarrod L. Norton, Elliott B. Slamovich, C. Venkatraman, and Said Mansour
- Subjects
Fabrication ,Materials science ,business.industry ,Oxide ,law.invention ,chemistry.chemical_compound ,chemistry ,law ,Electrode ,Optoelectronics ,Stencil lithography ,X-ray lithography ,Photolithography ,business ,Lithography ,Next-generation lithography - Abstract
Current metal/metal oxide patterning techniques typically involve photolithography, an expensive, time-consuming process, and/or a vacuum system, which also adds significantly to the cost. In this study, fabrication of metal oxide upper electrodes for Pb(ZrxTi1-x)O3 (PZT) memories by metallorganic decomposition (MOD) was coupled with laser beam patterning. Metal oxide organic precursors were treated with an absorption-enhancing dye and were spun on to ferroelectric PZT films followed by selective area laser beam exposure. This technique was employed to pattern RuO2 and (La,Sr)CoO3 electrodes. A variety of patterns (dot, line, and circular) were prepared which demonstrates the suitability of laser patterning for a variety of applications. The minimum power density required to generate a continuous conductive oxide pattern was found to be approximately 2.5 kW/cm2 at a scan speed of 25 mm/min. Resistivity values for the patterned lines were 660 Ω-cm for RuO2 and 59 mΩ-cm for LSCO.
- Published
- 1995
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35. Notes on the Association of Lissocarcinus polybiodes Adams and White, 1848 (Portunidae, Caphyrinae), with Sea Star Luidia Maculata Muller and Troschel, 1842
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Rajkumar Rajan, C. Venkatraman, G. Sivaleela, D. Paranthaman, P. Padmanaban, and K. Venkataraman
- Subjects
General Medicine - Published
- 2012
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36. First record of a Nicobar treeshrew nest in a fallen palm tree.
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Kamalakannan, Manokaran, G., Gokulakrishnan, C., Venkatraman, C., Sivaperuman, and Chandra, Kailash
- Subjects
PALMS ,FOREST reserves ,BIOSPHERE reserves - Abstract
The Nicobar treeshrew Tupaia nicobarica (Zelebor 1869) is an endemic species found in the Great & Little Nicobar Islands in the Andaman Sea, India. A unique nest site of an adult male of Nicobar treeshrew was directly recorded which was found in a fallen dead palm tree at the littoral forests of Galathea National Park, Great Nicobar Biosphere Reserve. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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37. Spatial and temporal analysis of road traffic crashes and ambulance responses in Lagos state, Nigeria.
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Odusola AO, Jeong D, Malolan C, Kim D, Venkatraman C, Kola-Korolo O, Idris O, Olaomi OO, and Nwariaku FE
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- Humans, Nigeria epidemiology, Cross-Sectional Studies, Risk Factors, Accidents, Traffic, Ambulances
- Abstract
Background: Sub-Saharan African countries, Nigeria inclusive, are constrained by grossly limited access to quality pre-hospital trauma care services (PTCS). Findings from pragmatic approaches that explore spatial and temporal trends of past road crashes can inform novel interventions. To improve access to PTCS and reduce burden of road traffic injuries we explored geospatial trends of past emergency responses to road traffic crashes (RTCs) by Lagos State Ambulance Service (LASAMBUS), assessed efficiency of responses, and outcomes of interventions by local government areas (LGAs) of crash., Methods: Using descriptive cross-sectional design and REDcap we explored pre-hospital care data of 1220 crash victims documented on LASAMBUS intervention forms from December 2017 to May 2018. We analyzed trends in days and times of calls, demographics of victims, locations of crashes and causes of delayed emergency responses. Assisted with STATA 16 and ArcGIS pro we conducted descriptive statistics and mapping of crash metrics including spatial and temporal relationships between times of the day, seasons of year, and crash LGA population density versus RTCs incidence. Descriptive analysis and mapping were used to assess relationships between 'Causes of Delayed response' and respective crash LGAs, and between Response Times and crash LGAs., Results: Incidences of RTCs were highest across peak commuting hours (07:00-12:59 and 13:00-18:59), rainy season and harmattan (foggy) months, and densely populated LGAs. Five urban LGAs accounted for over half of RTCs distributions: Eti-Osa (14.7%), Ikeja (14.4%), Kosofe (9.9%), Ikorodu (9.7%), and Alimosho (6.6%). On intervention forms with a Cause of Delay, Traffic Congestion (60%), and Poor Description (17.8%), had associations with LGA distribution. Two densely populated urban LGAs, Agege and Apapa were significantly associated with Traffic Congestion as a Cause of Delay. LASAMBUS was able to address crash in only 502 (36.8%) of the 1220 interventions. Other notable outcomes include: No Crash (false calls) (26.6%), and Crash Already Addressed (22.17%)., Conclusions: Geospatial analysis of past road crashes in Lagos state offered key insights into spatial and temporal trends of RTCs across LGAs, and identified operational constraints of state-organized PTCS and factors associated with delayed emergency responses. Findings can inform programmatic interventions to improve trauma care outcomes., (© 2023. The Author(s).)
- Published
- 2023
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38. Ecofriendly sol-gel-derived dye-sensitized solar cells with aluminium-doped tin oxide photoanode.
- Author
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Panneer NK, Venkatraman C, Bachan N, Wilson JJ, Edwin MA, Jesudasan AR, and Joseph MS
- Subjects
- Sunlight, Tin Compounds chemistry, Electrodes, Photochemical Processes, Solar Energy, Aluminum, Nanoparticles chemistry
- Abstract
The manuscript reports the fabrication of an eco-friendly sol gel dye-sensitized solar cell (DSSC) based on aluminium (Al)-doped tin oxide nanoparticles with different concentrations (0.5, 1, and 5 mol%) of Al providing enhanced optical and electrical properties than its bare counterparts. The physical, chemical, optical, and electrical properties of the as-synthesized nanoparticles were studied using different analytical tools. X-ray diffraction (XRD) study reveals the crystal structure of the prepared samples ascribed to SnO
2 nanoparticles uniformly with reduced crystallite size for Al-doped SnO2 nanoparticles. Field emission scanning electron microscope (FESEM) analysis reveals narrowing of particle size on doping with the Al, substantially enhancing the optical and surface characteristic features of the SnO2 nanoparticles. Photoconductivity studies indicate that all the samples have a good linear response with the increment of electric field in dark and photocurrent attributing to better photoconversion capability of the samples. Further, the optimized Al-doped SnO2 and bare SnO2 nanoparticles were subjected to sophisticated analytical studies such as high-resolution transmission electron microscope (HR-TEM) and X-ray photoelectron spectroscopy (XPS) for the better insight into their properties. The as-prepared Al-doped SnO2 nanoparticles in the present study record good optical, surface, and electrical properties which enhance their compatibility for possible photovoltaic applications especially in dye-sensitized solar cells as an environmentally safe alternate energy solution. Further, the current density-voltage (J-V) characteristics of the optimized Al-SnO2 and bare SnO2 photoanode component were probed for their suitability in DSSCs which disclosed enriched efficiency upon doping with aluminium nanoparticles., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)- Published
- 2023
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39. Assessment of Knowledge, Skills, and Preparedness of General-Duty Police on Prehospital Care of Road Traffic Accident Victims in Abuja, Nigeria.
- Author
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Ogunyemi K, Venkatraman C, Malolan C, Olaomi O, and Nwariaku FE
- Subjects
- Humans, Accidents, Traffic, Nigeria, Cross-Sectional Studies, Police, Emergency Medical Services
- Abstract
Objectives: Prompt prehospital care (PHC) is essential for improving outcomes of road traffic accident victims. Previous studies in Nigeria show that little or no PHC is delivered to trauma victims by first responders. This study was conducted to assess police officers' experience with FA/BLS, to identify gaps in their FA/BLS knowledge and skills, and assess police stations' FA/BLS equipment capacity for PHC of road traffic accident victims., Methods: This cross-sectional study was conducted among 428 GD police in Abuja between November and December 2018. Respondents were selected using stratified random sampling with proportional allocation method. Data were collected using self-administered electronic semi-structured questionnaires. Data analysis was done using STATA v 14.0 (StataCorp, College Station, TX). Chi-square and multivariate logistic regression were used to assess associations., Results: We analyzed data from 419 respondents. Almost all (90.2%) of the police were aware of FA/BLS. The proportion of police with poor, fair, and good knowledge and skills on FA/BLS were 15.3%, 79.0%, and 5.7%, respectively. Tertiary (OR = 3.35, 95% CI: 1.01-11.11, P = 0.048) and postgraduate (OR = 6.89, 95% CI: 1.63-29.19, P = 0.009) levels of education had statistically significant association with good knowledge and skills., Conclusion: This highlights the need to implement an educational intervention to increase FA/BLS competencies within the first responder population.
- Published
- 2022
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40. Association of Vaginal Progesterone Treatment With Prevention of Recurrent Preterm Birth.
- Author
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Nelson DB, Lafferty A, Venkatraman C, McDonald JG, Eckert KM, McIntire DD, and Spong CY
- Subjects
- Pregnancy, Infant, Female, Infant, Newborn, Humans, Adult, Cohort Studies, Prospective Studies, Administration, Intravaginal, Progesterone therapeutic use, Premature Birth prevention & control, Premature Birth drug therapy
- Abstract
Importance: Preterm birth (PTB) is the leading cause of infant morbidity and mortality worldwide. It has been suggested that vaginal progesterone (VP) treatment may reduce the recurrence of PTB., Objective: To evaluate the association of VP treatment with prevention of recurrent PTB among patients with a singleton pregnancy., Design, Setting, and Participants: This prospective, observational cohort study, set in a public health care system for inner-city pregnant patients, enrolled patients with prior spontaneous PTB (gestational age, ≤35 weeks) receiving VP from May 15, 2017, to May 7, 2019. Patients who delivered between 1998 and 2011 served as a referent cohort matched 3:1 for obesity, race and ethnicity, and individual specific preterm birth history. Statistical analysis was performed from August 19, 2021, to September 2, 2022., Exposure: Patients received 90 mg of vaginal progesterone, 8%, nightly, initiated between 16 weeks and 0 days and 20 weeks and 6 days of pregnancy until 36 weeks and 6 days of pregnancy or delivery., Main Outcomes and Measures: The primary outcome was overall rate of recurrent PTB at 35 weeks or less of patients given VP compared with the 3:1 matched untreated historical controls. Secondary outcomes included assessment of PTB according to adherence (≥80% completing scheduled doses), duration of pregnancy relative to index gestational age, progesterone blood levels, and outcomes for those who declined VP., Results: A total of 417 patients (mean [SD] age, 30.4 [5.9] years; 64 Black patients [15.3%]; 272 [65.2%] with a body mass index of ≥30) received VP and were matched with 1251 controls (mean [SD] age, 28.8 [5.7] years; 192 Black patients [15.3%]; 816 [65.2%] with a body mass index of ≥30). The overall rate of recurrent PTB was 24.0% (100 of 417; 95% CI, 20.0%-28.4%) for the VP cohort compared with 16.8% (1394 of 8278) expected in the matched historical controls. Adherence was not associated with lower rates of recurrent PTB compared with nonadherence (odds ratio, 0.87 [95% CI, 0.51-1.41]). The mean difference between historical matched controls and those using VP was 0.2 weeks (95% CI, -1.4 to 1.0 weeks) without improvement in the interval of recurrent PTB after the implementation of VP (P = .73). Progesterone blood levels for patients who were adherent compared with those who were nonadherent were not significantly different at either 24 or 32 weeks (24 weeks: 99 ng/mL [95% CI, 85-121 ng/mL] vs 104 ng/mL [95% CI, 89-125 ng/mL]; P = .16; 32 weeks: 200 ng/mL [95% CI, 171-242 ng/mL] vs 196 ng/mL [95% CI, 155-271 ng/mL]; P = .69)., Conclusions and Relevance: This cohort study of patients with a current singleton pregnancy suggests that VP was not associated with a reduction in recurrent PTB.
- Published
- 2022
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41. Complete mitogenome of the endangered and endemic Nicobar treeshrew (Tupaia nicobarica) and comparison with other Scandentians.
- Author
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Kundu S, Pakrashi A, Kamalakannan M, Singha D, Tyagi K, Banerjee D, Venkatraman C, and Kumar V
- Subjects
- Animals, RNA, Transfer genetics, RNA, Ribosomal genetics, India, Genome, Mitochondrial genetics, Phylogeny, Endangered Species
- Abstract
The Nicobar treeshrew (Tupaia nicobarica) is an endangered small mammal endemic to the Nicobar Island of the Andaman Sea, India regarded as an alternative experimental animal model in biomedical research. The present study aimed to assemble the first mitochondrial genome of T. nicobarica to elucidate its phylogenetic position with respect to other Scandentians. The structure and variation of the novel mitochondrial genome were analyzed and compared with other Scandentians. The complete mitogenome (17,164 bp) encodes 37 genes, including 13 protein-coding genes (PCGs), 22 transfer RNA (tRNAs), two ribosomal RNA (rRNAs), and one control region (CR). Most of the genes were encoded on majority strand, except nad6 and eight tRNAs. The nonsynonymous/synonymous ratio in all PCGs indicates strong negative selection among all Tupaiidae species. The comparative study of CRs revealed the occurrence of tandem repeats (CGTACA) found in T. nicobarica. The phylogenetic analyses (Maximum Likelihood and Bayesian Inference) showed distinct clustering of T. nicobarica with high branch supports and depict a substantial divergence time (12-19 MYA) from the ancestor lineage of Tupaiidae. The 16S rRNA dataset corroborates the taxonomic rank of two subspecies of T. nicobarica from the Great and Little Nicobar Islands. In the future, whole nuclear genome sequencing is necessary to further improve our understanding of evolutionary relationships among treeshrews, and will have implications for biomedical research., (© 2022. The Author(s).)
- Published
- 2022
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42. Spike protein multiorgan tropism suppressed by antibodies targeting SARS-CoV-2.
- Author
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Brady M, McQuaid C, Solorzano A, Johnson A, Combs A, Venkatraman C, Rahman A, Leyva H, Kwok WE, Wood RW, and Deane R
- Subjects
- Animals, Mice, Brain virology, Brain metabolism, Lung virology, Lung immunology, Lung metabolism, Tissue Distribution, Antibodies, Viral immunology, COVID-19 immunology, COVID-19 virology, COVID-19 metabolism, SARS-CoV-2 immunology, SARS-CoV-2 physiology, Spike Glycoprotein, Coronavirus immunology, Spike Glycoprotein, Coronavirus metabolism, Viral Tropism
- Abstract
While there is SARS-CoV-2 multiorgan tropism in severely infected COVID-19 patients, it's unclear if this occurs in healthy young individuals. In addition, for antibodies that target the spike protein (SP), it's unclear if these reduce SARS-CoV-2/SP multiorgan tropism equally. We used fluorescently labeled SP-NIRF to study viral behavior, using an in vivo dynamic imaging system and ex in vivo tissue analysis, in young mice. We found a SP body-wide biodistribution followed by a slow regional elimination, except for the liver, which showed an accumulation. SP uptake was highest for the lungs, and this was followed by kidney, heart and liver, but, unlike the choroid plexus, it was not detected in the brain parenchyma or CSF. Thus, the brain vascular barriers were effective in restricting the entry of SP into brain parenchyma in young healthy mice. While both anti-ACE2 and anti-SP antibodies suppressed SP biodistribution and organ uptake, anti-SP antibody was more effective. By extension, our data support the efficacy of these antibodies on SARS-CoV-2 multiorgan tropism, which could determine COVID-19 organ-specific outcomes., (© 2021. The Author(s).)
- Published
- 2021
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- View/download PDF
43. Lagos state ambulance service: a performance evaluation.
- Author
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Venkatraman C, Odusola AO, Malolan C, Kola-Korolo O, Olaomi O, Idris J, and Nwariaku FE
- Subjects
- Accidents, Traffic, Humans, Nigeria, Ambulances, Emergency Medical Services
- Abstract
Objectives: The mortality rate from road traffic accidents (RTAs) in Nigeria is almost double that of the USA. In Nigeria, the first emergency medical services (EMS) system was established in March 2001, The Lagos State Ambulance Service (LASAMBUS). The objectives of this study are to (1) determine the burden of RTAs in Lagos, (2) assess RTA call outcomes, and (3) analyze LASAMBUS's response time and causes for delay., Methodology: We reviewed completed LASAMBUS intervention forms spanning December 2017 to May 2018. We categorized the call outcomes into five groups: I. Addressed Crash, II. No Crash (False Call), III. Crash Already Addressed, IV. Did Not Respond, and V. Other. We further explored associations between the (1) causes for delay and outcomes and (2) response times and the outcomes., Results: Overall, we analyzed 1352 intervention forms. We found that LASAMBUS did not address 53% of the RTA calls that they received. Of this, Outcome II. No Crash (False Call) accounted for 26% and Outcome III. Crash Already Addressed accounted for 22%. Self-reported causes for delay were recorded in 180 forms, representing 13.7% of the RTA burden. Traffic congestion accounted for 60% of this distribution., Conclusion: LASAMBUS response rates are significantly lower than response rates in high-income countries such as the USA and lead to increased RTA mortality rates. Eliminating causes for delay will improve both LASAMBUS effectiveness and RTA victims' health outcomes. Changing the public perception of LASAMBUS and standardizing LASAMBUS' contact information will aid this as well., (© 2020. The Author(s).)
- Published
- 2021
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44. Global community perception of 'surgical care' as a public health issue: a cross sectional survey.
- Author
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Lubis N, Cherian MN, Venkatraman C, and Nwariaku FE
- Subjects
- Cross-Sectional Studies, Global Health, Humans, Perception, Public Health, Universal Health Insurance
- Abstract
Background: In the last decade surgical care has been propelled into the public health domain with the establishment of a World Health Organisation (WHO) designated programme and key publications. The passing of the historic World Health Assembly Resolution (WHA) acknowledged surgical care as a vital component towards achieving Universal Health Coverage (UHC). We conducted the first worldwide survey to explore the perception of surgical care as a public health issue., Method: The anonymous, cross sectional survey targeted worldwide participants across a range of professional backgrounds, including non-medical using virtual snowball sampling method (in English) using Google Forms (Google Inc., Mountain View, CA, USA) from 20th February 2019 to 25th June 2019. The survey questions were designed to gauge awareness on Sustainable Development Goals (SDGs), UHC, WHO programmes and key publications on surgical care as well as perception of surgical care as a priority topic in public health., Results: The survey was completed by 1954 respondents from 118 countries. Respondents were least aware of surgical care as a teaching topic in public health courses (27%; n = 526) and as a WHO programme (20%; n = 384). 82% of respondents were aware of UHC (n = 1599) and of this 72% (n = 1152) agreed that surgical care fits within UHC. While 77% (n = 1495) of respondents were aware of SDGs, only 19% (n = 370) agreed that surgery was a priority to meet SDGs. 48% (n = 941) rated surgical care as a cost-effective component of Primary Health Care. 88% (n = 1712) respondents had not read the WHA Resolution on 'Strengthening emergency and essential surgical care and anaesthesia as a component of UHC'., Conclusion: There is still a widespread gap in awareness on the importance of surgical care as a public health issue amongst our respondents. Surgical care was not seen as a priority to reach the SDGs, less visible as a WHO programme and not perceived as an important topic for public health courses.
- Published
- 2021
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45. Discovery of a new mammal species (Soricidae: Eulipotyphla) from Narcondam volcanic island, India.
- Author
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Kamalakannan M, Sivaperuman C, Kundu S, Gokulakrishnan G, Venkatraman C, and Chandra K
- Subjects
- Animals, Cytochromes b genetics, Ecosystem, Genome genetics, India, Islands, Mitochondria genetics, Myanmar, Shrews anatomy & histology, Shrews classification, Shrews genetics
- Abstract
We discovered a new Crocidura species of shrew (Soricidae: Eulipotyphla) from Narcondam Island, India by using both morphological and molecular approaches. The new species, Crocidura narcondamica sp. nov. is of medium size (head and body lengths) and has a distinct external morphology (darker grey dense fur with a thick, darker tail) and craniodental characters (braincase is rounded and elevated with weak lambdoidal ridges) in comparison to other close congeners. This is the first discovery of a shrew from this volcanic island and increases the total number of Crocidura species catalogued in the Indian checklist of mammals to 12. The newly discovered species shows substantial genetic distances (12.02% to 16.61%) to other Crocidura species known from the Indian mainland, the Andaman and Nicobar Archipelago, Myanmar, and from Sumatra. Both Maximum-Likelihood and Bayesian phylogenetic inferences, based on mitochondrial (cytochrome b) gene sequences showed distinct clustering of all included soricid species and exhibit congruence with the previous evolutionary hypothesis on this mammalian group. The present phylogenetic analyses also furnished the evolutionary placement of the newly discovered species within the genus Crocidura.
- Published
- 2021
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46. Digging out the keys in the heap of seized pangolin scales: up scaling pangolin conservation using wildlife forensics.
- Author
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Priyambada P, Jabin G, Singh A, Ghosh A, Singh SK, Chatterjee M, Venkatraman C, Chandra K, Sharma LK, and Thakur M
- Abstract
Pangolins, despite banned through legislative measures, are threatened by heavy illegal poaching for the demand of meat and scales in the making of Traditional East Asian Medicines (TEAM), resulting in severe decline of the population sizes across the distribution range. Species assignment from the confiscated scales is pre-requisite to enforce the appropriate national and international law and legislations in the successful prosecution of the cases in the court of law. In the present study, we characterised the morphological features in voucher specimens of the Indian pangolin (Manis crassicaudata) and Chinese pangolin (Manis pentadactyla) and used the identified keys to establish the species identity from the confiscated scales. We investigated intra and inter genetic variations by sequencing 624 scales of pangolin for cytb gene and obtained unique haplotypes to Indian and Chinese pangolins by comparing sequences with all eight pangolin species. Scales from the voucher specimens, which varied in the size, shape and weight, were measured for morphological features to establish species signature of Indian and Chinese pangolins. The cumulative success of species assignment using morphological features from the confiscated scales was 98.33% and 100% from the large and caudal scales, respectively. The present study has generated reference signature of Indian and Chinese pangolins from the scales and facilitates the law enforcements for taking spot decision by ascertaining species identity from the seized scales., Competing Interests: Conflict of interest Authors declare that they have no conflict of interest., (Copyright © 2021 Elsevier B.V. All rights reserved.)
- Published
- 2021
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47. Adaptive spatial planning of protected area network for conserving the Himalayan brown bear.
- Author
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Mukherjee T, Sharma LK, Kumar V, Sharief A, Dutta R, Kumar M, Joshi BD, Thakur M, Venkatraman C, and Chandra K
- Subjects
- Acclimatization, Animals, Climate Change, Conservation of Natural Resources, Ecosystem, Goals, Movement, Ursidae
- Abstract
Large mammals that occur in low densities, particularly in the high-altitude areas, are globally threatened due to fragile climatic and ecological envelopes. Among bear species, the Himalayan brown bear (Ursus arctos isabellinus) has a distribution that is restricted to Himalayan highlands with relatively small and fragmented populations. To date, very little scientific information on the Himalayan brown bear, which is vital for the conservation of the species and the management of its habitats, especially in protected areas of the landscape, is available. The present study aims to understand the effectiveness of existing Himalayan Protected Areas in terms of representativeness for the conservation of Himalayan brown bear (HBB), an umbrella species in high-altitude habitats of the Himalayan region. We used the ensemble approach of the species distribution model and then assessed biological connectivity to predict the current and future distribution and movement of HBB in climate change scenarios for the year 2050. Approximately 33 protected areas (PAs) currently possess suitable habitats. Our model suggests a massive decline of approximately 73.38% and 72.87% under 4.5 and 8.5 representative concentration pathway (RCP) respectively in the year 2050 compared with the current distribution. The predicted change in suitability will result in loss of habitats from thirteen PAs; eight will become completely uninhabitable by the year 2050, followed by loss of connectivity in the majority of PAs. Habitat configuration analysis suggested a 40% decline in the number of suitable patches, a reduction in large habitat patches (up to 50%) and aggregation of suitable areas (9%) by 2050, indicating fragmentation. The predicted change in geographic isotherm will result in loss of habitats from thirteen PAs, eight of them will become completely inhabitable. Hence, these PAs may lose their effectiveness and representativeness in achieving the very objective of their existence or conservation goals. Therefore, we recommend adaptive spatial planning for protecting suitable habitats distributed outside the PA for climate change adaptation., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2021
- Full Text
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48. Cerebrospinal fluid drainage kinetics across the cribriform plate are reduced with aging.
- Author
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Brady M, Rahman A, Combs A, Venkatraman C, Kasper RT, McQuaid C, Kwok WE, Wood RW, and Deane R
- Subjects
- Animals, Kinetics, Mice, Mice, Inbred C57BL, Spectroscopy, Near-Infrared, Aging physiology, Cerebrospinal Fluid physiology, Ethmoid Bone physiology, Spinal Cord physiology, Subarachnoid Space physiology
- Abstract
Background: Continuous circulation and drainage of cerebrospinal fluid (CSF) are essential for the elimination of CSF-borne metabolic products and neuronal function. While multiple CSF drainage pathways have been identified, the significance of each to normal drainage and whether there are differential changes at CSF outflow regions in the aging brain are unclear., Methods: Dynamic in vivo imaging of near infrared fluorescently-labeled albumin was used to simultaneously visualize the flow of CSF at outflow regions on the dorsal side (transcranial and -spinal) of the central nervous system. This was followed by kinetic analysis, which included the elimination rate constants for these regions. In addition, tracer distribution in ex vivo tissues were assessed, including the nasal/cribriform region, dorsal and ventral surfaces of the brain, spinal cord, cranial dura, skull base, optic and trigeminal nerves and cervical lymph nodes., Results: Based on the in vivo data, there was evidence of CSF elimination, as determined by the rate of clearance, from the nasal route across the cribriform plate and spinal subarachnoid space, but not from the dorsal dural regions. Using ex vivo tissue samples, the presence of tracer was confirmed in the cribriform area and olfactory regions, around pial blood vessels, spinal subarachnoid space, spinal cord and cervical lymph nodes but not for the dorsal dura, skull base or the other cranial nerves. Also, ex vivo tissues showed retention of tracer along brain fissures and regions associated with cisterns on the brain surfaces, but not in the brain parenchyma. Aging reduced CSF elimination across the cribriform plate but not that from the spinal SAS nor retention on the brain surfaces., Conclusions: Collectively, these data show that the main CSF outflow sites were the nasal region across the cribriform plate and from the spinal regions in mice. In young adult mice, the contribution of the nasal and cribriform route to outflow was much higher than from the spinal regions. In older mice, the contribution of the nasal route to CSF outflow was reduced significantly but not for the spinal routes. This kinetic approach may have significance in determining early changes in CSF drainage in neurological disorder, age-related cognitive decline and brain diseases.
- Published
- 2020
- Full Text
- View/download PDF
49. Pangolin Indexing System: implications in forensic surveillance of large seizures.
- Author
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Singh A, Priyambada P, Jabin G, Singh SK, Joshi BD, Venkatraman C, Chandra K, Sharma LK, and Thakur M
- Subjects
- Animals, China, Crime prevention & control, Genetics, Population, Genotype, India, Malaysia, Species Specificity, DNA Fingerprinting methods, Dinucleotide Repeats, Endangered Species, Genetic Loci, Pangolins genetics
- Abstract
Demand for pangolin scales in East Asia has increased dramatically in the past two decades, raising concern to the pangolin survival and bringing them to the brink of local extinction. Enumerating the number of individuals from the seized pangolin scales primarily goes undocumented, mostly due to the unavailability of the appropriate methods. In this study, we developed a Pangolin Indexing System, a multi-locus STR panel of eight dinucleotide microsatellites that showed promising results in individualization and assignment of scales into Chinese and Indian pangolins. The combined power of exclusion was 0.83 and 0.99 for Chinese and Indian pangolin. The select panel of eight polymorphic STRs exhibited the cumulative probability of identity 3.7 × 10
-9 for Indian pangolin and 3.6 × 10-7 for Chinese pangolin and identified 51 unique genotypes from the 74 scales selected from the four pangolin seizures. The study demonstrated the first report of cross-species validation of STRs developed from Malayan pangolin to Indian pangolin and showed the potential application of Pangolin Indexing System in screening of large seizures through DNA profiling from the scales of Indian and Chinese pangolin.- Published
- 2020
- Full Text
- View/download PDF
50. Decreasing Trends in Road Traffic Injury Incidence and Mortality in Nigeria: A Ten-Year Analysis.
- Author
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Venkatraman C, Olowu O, Turkmani D, Hynan L, and Nwariaku FE
- Subjects
- Accidents, Traffic mortality, Accidents, Traffic statistics & numerical data, Geography, Humans, Incidence, Nigeria epidemiology, Retrospective Studies, Wounds and Injuries etiology, Accidents, Traffic trends, Mortality trends, Wounds and Injuries epidemiology
- Abstract
Background: Road traffic accidents constitute a significant public health burden in Nigeria. In this study, we aim to (1) characterize the temporal burden of road traffic injury (RTI) and mortality rates in Nigeria over a decade, (2) identify regional RTI incidence, mortality trends, and high-risk regions, and (3) assess the impact of state population on injury and mortality., Materials and Methods: We retrospectively reviewed aggregate state-level RTI incidence and mortality counts reported by the Federal Road Safety Corps from January 2001 through December 2010. We also reviewed population data from the National Population Commission. In addition to national analyses, regional analyses were performed in Nigeria's six geopolitical zones and one Federal Capital Territory (FCT). Regression analysis was also performed to determine the relationship between population and RTI incidence and mortality., Results: The national median RTI incidence and mortality rates declined by 53% and 75%, respectively, between 2001 and 2010. Analysis by geopolitical zone yielded the greatest increases for both injury and mortality in the FCT and the greatest decreases for both in the South-South region. The average geopolitical zone, apart from the FCT, experienced a 24% decrease in the incidence rate and a 69% decrease in the mortality rate. An analysis of variance, run to assess potential differences in RTI incidence and mortality rates by state population, yielded significant values of P = 0.0023 for injury and P = 0.0002 for mortality., Conclusions: Acknowledging the potential for underreporting, a more holistic surveillance approach would generate more accurate data for future policy creation to improve clinical outcomes., (Copyright © 2019 Elsevier Inc. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
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