The present study demonstrates the spatial analysis and mapping of fish and different measures of environmental parameters and fish diversity of Pong reservoir, Himachal Pradesh, using Kriging ...spatial interpolation methods for geographical information system mapping. Seasonal data on environmental parameters, potential fish habitat and fish diversity was collected from lentic (dam), lentic (reservoir), transitional and lotic zone of the reservoir.. Important environmental parameters like water temperature, dissolved oxygen, electrical conductivity, water depth and transparency showed variations across the different zones of the reservoir. The sediment of the reservoir was sandy clay loam in nature as per texture analysis. Fish species richness, Shannon index and evenness index showed a similarity of the lotic and lentic (reservoir) zones of the reservoir. Six potential fish breeding grounds were identified in the reservoir indicating high conservation significance. The analysis of data showed a declining trend in fish production from 456.9 tonnes during the decade 1976–1987 to 347.91 tonnes during 2009–2020. The factors like anthropogenic climate change, predation of a stocked fish juvenile by water birds, undersized fish stocking and unscientific management are the probable reasons for the decreasing fish production. The spatial variation pattern of the water spread area, environmental parameters, fish catch and potential fish breeding grounds depicted in the GIS platform can be used as an important information base by the policy makers for fisheries management. The stocking of large size fish as a stocking material and adequate protection of the potential fish breeding grounds are the key advisories for the sustainable enhancement of fisheries as well as conservation.
Synopsis
Due to the bulk electron capture from the molecular shell of fullerenes by incoming positron projectiles and a dephasing effect across the shell width, the positronium formation signal ...yields diffraction fringes in the target recoil momentum space. Our results show the variance in the separation and shape of the fringe pattern as a function of the fullerene size from C
60
to larger C
240
.
Synopsis We study the photoionization properties of the Nan (n=40 and 92) clusters in a spherical jellium frame using the Kohn-Sham density functional method. Two well known form of ...exchange-correlation (xc) functional in the framework of local density approximation (LDA) with Gunnarsson-Lundqvist parametrization1 are employed: i) the electron self-interaction correction (LDA-SIC) 1 and ii) the van Leeuwen and Baerends model potential (LDA-LB94) 1.
Synopsis
We study the photoionization properties of the Na
n
(n=40 and 92) clusters in a spherical jellium frame using the Kohn-Sham density functional method. Two well known form of ...exchange-correlation (xc) functional in the framework of local density approximation (LDA) with Gunnarsson-Lundqvist parametrization1 are employed: i) the electron self-interaction correction (LDA-SIC) 1 and ii) the van Leeuwen and Baerends model potential (LDA-LB94) 1.
Synopsis We show that the dynamical electron correlation suppresses the dipole field of incoming photon while inducing a strong attractive force at the spectral region of the giant plasmon resonance ...of C60. A signature of this force is seen in the form of a binding well in the imaginary part of the induced potential. This attraction can significantly influence the emerging photoelectron's temporal delay behavior.
Context . Long-period transiting exoplanets bridge the gap between the bulk of transit- and Doppler-based exoplanet discoveries, providing key insights into the formation and evolution of planetary ...systems. The wider separation between these planets and their host stars results in the exoplanets typically experiencing less radiation from their host stars; hence, they should maintain more of their original atmospheres, which can be probed during transit via transmission spectroscopy. Although the known population of long-period transiting exoplanets is relatively sparse, surveys performed by the Transiting Exoplanet Survey Satellite (TESS) and the Next Generation Transit Survey (NGTS) are now discovering new exoplanets to fill in this crucial region of the exoplanetary parameter space. Aims . This study aims to characterise a new long-period transiting exoplanet by following up on a single-transit candidate found in the TESS mission. Methods . The TOI-4862 system was monitored using a combination of photometric instruments (TESS, NGTS, and EulerCam) and spectroscopic instruments (CORALIE, FEROS, HARPS, and PFS) in order to determine the period, radius, and mass of the long-period transiting exoplanet NGTS-30 b/TOI-4862 b. These observations were then fitted simultaneously to determine precise values for the properties and orbital parameters of the exoplanet, as well as the refined stellar parameters of the host star. Results . We present the discovery of a long-period ( P = 98.29838 ± 0.00010 day) Jupiter-sized (0.928 ± 0.032 R J ; 0.960 ± 0.056 M J ) planet transiting a 1.1 Gyr old G-type star, one of the youngest warm Jupiters discovered to date. NGTS-30 b/TOI-4862 b has a moderate eccentricity (0.294 −0.010 +0.014 ), meaning that its equilibrium temperature can be expected to vary from 274 −46 +30 K to 500 −84 +55 K over the course of its orbit. Through interior modelling, NGTS-30 b/TOI-4862b was found to have a heavy element mass fraction of 0.23 −0.06 +0.05 and a heavy element enrichment ( Z p / Z ★ ) of 20 −6 +5 , making it metal-enriched compared to its host star. Conclusions . NGTS-30 b/TOI-4862 b is one of the youngest well-characterised long-period exoplanets found to date and will therefore be important in the quest to understanding the formation and evolution of exoplanets across the full range of orbital separations and ages.
Intensive fish farming systems have led to increase in disease incidence, due to higher stocking density, high organic matter levels, and poor quality of the aquatic environment. Diseased fish ...samples showing hemorrhages and reddish lesions were collected from different freshwater fish farms located at three different districts of West Bengal, India (Burdwan, North 24 Parganas, and Nadia). The present study was conducted to evaluate the genetic diversity of ten different
Klebsiella pneumoniae
strains isolated from different infected freshwater fish samples based on 16S rRNA gene sequence analysis. Primarily,
Klebsiella
-specific media was used for the isolation and characterization of
Klebsiella pneumoniae
. Further, through a biochemical test, all the strains were confirmed as
K. pneumoniae
. PCR analysis of 16S–23S internal transcribed spacer (PCR ribotyping) was carried out to study the species variation within different
Klebsiella pneumoniae
isolates. For all the isolates, a conserved PCR ribotype pattern was observed while differing from other bacterial species. Phylogenetic study showed the high degree of homology with diverse source of other strains. The multiple antibiotic resistance (MAR) values of the present study for the isolates were found to be 0.468. MAR value above 0.2 indicates that the source of isolation was highly contaminated with antibiotics. Based on the 16S rRNA gene sequence analysis, the present study revealed the genetic diversity of
Klebsiella pneumoniae
isolated from the different diseased fish farms of West Bengal. All the strains were found to be hypermucoviscous and multidrug-resistant, thus making it pathogenic towards the host organisms. Further, the study revealed a high prevalence of
K. pneumoniae
in aquaculture farms, representing a risk towards successful aquaculture.
In this paper we study
δ
-ideals of a pseudocomplemented semilattice. We give some characterizations of
δ
-ideals. We also prove Stone type separation theorem for
δ
-ideals of a pseudocomplemented ...semilattice. We show that the set of
δ
-ideals of a pseudocomplemented semilattice form a distributive pseudocomplemented lattice. We also prove that the set of principal
δ
-ideals form a Boolean algebra.
Synopsis We investigate the electron dynamics at various monocrystalline metal surfaces with stepped vicinal nanostructures. The unoccupied bands of the surface superlattice are resonantly excited ...via the charge transfer interaction of the surface with a H− ion which flies by at grazing angles. The ion survival exhibits modulations as a function of the vicinal-terrace size and shows peaks at energies that access the image state subbands.
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