32 research outputs found
Daytime sodium airglow emission measurements over Trivandrum using a scanning monochromator: first results
This paper presents measurement of daytime Sodium (Na) airglow emissions at 589.6 nm wavelength using a ground based 1-m scanning monochromator from Trivandrum (8.5° N, 77° E, 0.5° N dip latitude), a near-equatorial station in India. The Na emission intensity exhibits significant temporal variability within a day and from one day to another. The Na intensity has been compared with the daytime OH airglow intensity at 731.6 nm simultaneously measured using the unique Multiwavelength Dayglow Photometer (MWDPM). The temporal variabilities of the Na and OH intensities corroborate each other in most of the occasions without any appreciable time delay, although a small time delay up to ˜10 min has been observed at times. It appears that the variability of daytime Na emissions is influenced too by the photo-chemical excitations. The observed similarities in the Na and OH intensities are believed to be due to the similar roles played by [O] and O3 (in their photo-chemical excitations) and the dynamics occurring at about the same altitude region (˜90 km). It has also been found that the gravity waves play significant role in producing the short-scale oscillations in these emissions
Occurrence of a rare lambridiform fish, Desmodema polystictum (Ogilby, 1898) from Andaman coast of India
The present study reveals the first documented distribution record of Desmodema polystictum (Ogilby, 1898) from the Andaman coast, eastern Indian Ocean. The species is rare in nature and the knowledge regarding the taxonomy, ecology and distribution is still limited. Only few records have been come from the Indian Ocean. The study is based on a single specimen (34 cm total length) collected from the northeastern region of Andaman Islands, India. The present record of D. polystictum from Andaman waters provides greater latitude and depth distribution than previously acknowledged from the Indian Exclusive Economic zone. Along with the comparative morphometric and meristic data from previous reports, description of present specimen as well as distributional information are also provided and discussed
Detection and molecular characterisation of Mycoplasma spp. from respiratory tract infections in pigs
Achieving food security involves the maintenance of intensive production systems and
large animal populations where infectious diseases are the most important challenge that need to
be addressed. Respiratory infections in pigs are a formidable threat to swine farmers worldwide.
It is multifactorial and is caused by the interplay between bacterial pathogens, viral agents and
environmental factors. The present study aimed to identify mycoplasmal agents causing respiratory
infections in pigs. A total of 43 samples, comprising of nasal swabs, and necropsy samples with
pneumonic lesions were collected. The DNA extracted from the samples were subjected to
Mycoplasma genus-specific, followed by species-specific PCR. Twenty five samples were positive
for Mycoplasma spp., but further molecular detection performed through species-specific primers,
revealed that 12 samples were positive for M. hyorhinis. None of the samples were positive for M.
hyopneumoniae. The identity of the amplicons were confirmed by nucleic acid sequencing and
BLAST analysis. The evolutionary relationship between the detected organisms was also studied
by phylogenetic analysis. This study hints at the significance of M. hyorhinis in causing respiratory
infections in swine and also suggests that M. hyopneumoniae may not be a significant health
hazard for swine populations of north Kerala
Eclipses observed by LYRA - a sensitive tool to test the models for the solar irradiance
We analyze the light curves of the recent solar eclipses measured by the
Herzberg channel (200-220 nm) of the Large Yield RAdiometer (LYRA) onboard
PROBA-2. The measurements allow us to accurately retrieve the center- to-limb
variations (CLV) of the solar brightness. The formation height of the radiation
depends on the observing angle so the examination of the CLV provide
information about a broad range of heights in the solar atmosphere. We employ
the 1D NLTE radiative transfer COde for Solar Irradiance (COSI) to model the
measured light curves and corresponding CLV dependencies. The modeling is used
to test and constrain the existing 1D models of the solar atmosphere, e.g. the
temperature structure of the photosphere and the treatment of the pseudo-
continuum opacities in the Herzberg continuum range. We show that COSI can
accurately reproduce not only the irradiance from the entire solar disk, but
also the measured CLV. It hence can be used as a reliable tool for modeling the
variability of the spectral solar irradiance.Comment: 19 pages, 9 figures, Solar Physic
Signatures of Sudden Storm Commencement on the equatorial thermospheric dayglow
It has been observed that the OI 630.0 nm dayglow emission over a dip equatorial station, Trivandrum (8.5° N, 77° E, dip 0.5° N), India registered an abrupt increase of ~ 2000 R during the compression phase of the magnetosphere as dictated by a sudden increase in solar wind ram pressure. Furthermore, an unusual depletion of these emissions has been observed during the eastward interplanetary electric field (IEF), concomitant with southward excursion of IMF Bz. The ionosonde and magnetometer observations confirmed the effects of prompt penetration electric field (PPEF). Associated with the eastward PPEF, formation of F3 layers were also noticed. These unique results, which emphasize the effect of Sudden Storm Commencement/IEF on these equatorial daytime airglow emissions are discussed in context of changes in the equatorial zonal electric field and F region height variations associated with polar/auroral activities due to the magnetosphere-ionosphere coupling
Deep–sea Eels (Teleostei: Anguilliformes) of the Indian EEZ: Systematics, Distribution and Biology
Redescription of Congrhynchus talabonoides Fowler, 1934 (Anguilliformes: Congridae) based on specimens collected from the Philippines, Taiwan and India
Smith, David G., Ho, Hsuan-Ching, Sumod, K. S. (2018): Redescription of Congrhynchus talabonoides Fowler, 1934 (Anguilliformes: Congridae) based on specimens collected from the Philippines, Taiwan and India. Zootaxa 4454 (1): 228-232, DOI: 10.11646/zootaxa.4454.1.1
Domino cyclization–alkylation protocol for the synthesis of 2,3-functionalized indoles from o-alkynylanilines and allylic alcohols
A practical and efficient protocol for the one-pot synthesis of 2,3-substituted indoles was developed via a palladacycle catalyzed domino cyclization–alkylation reaction involving 2-alkynylanilines and allylic alcohols under mild conditions without any additives
Description of a new species of deep-water snake eel, Ophichthus mccoskeri (Ophichthidae: Ophichthinae) from Andaman Sea, India
Sumod, K. S., Hibino, Yusuke, Manjabrayakath, Hashim, Sanjeevan, V. N. (2019): Description of a new species of deep-water snake eel, Ophichthus mccoskeri (Ophichthidae: Ophichthinae) from Andaman Sea, India. Zootaxa 4686 (1): 112-118, DOI: https://doi.org/10.11646/zootaxa.4686.1.