Cyclic Symmetry of Riemann Tensor in Fuzzy Graph Theory

In this paper, we define a graph-theoretic analog for the Riemann tensor and analyze properties of the cyclic symmetry. We have developed a fuzzy graph-theoretic analog of the Riemann tensor and have analyzed its properties. We have also shown how the fuzzy analog satisfies the properties of the 6X6 matrix of the Riemann tensor by expressing it as a union of the fuzzy complete graph formed by the permuting vertex set and a Levi-Civita graph analog. We have concluded the paper with a brief discussion on the similarities between the properties of the fuzzy graphical analog and the Riemann tensor and how it can be a plausible analogous model for the Petrov-Penrose classification.Comment: 12 pages, 1 figur

Necropsy findings and observations on marine mammals stranded in Gulf of Mannar coast

A dead female dolphin was washed ashore on 19 April 2016 at Singhivalaikuchu, near Vedhalai, Ramanathapuram district, Tamil Nadu along the coast of Gulf of Mannar (N.09.260700; E.79.084858). Based on morphological features and teeth pattern, the specimen was identified as Indo-pacific bottlenose dolphin, Tursiops aduncus. A total of 26 morphometric parameters were recorded

How privacy practices affect customer commitment in the sharing economy: A study of Airbnb through an institutional perspective

YesPrivacy is an emerging issue for home-sharing platforms such as Airbnb. Home-sharing providers (business customers) are subject to both digital privacy risks (e.g., data breaches and unauthorized data access) and physical privacy risks (e.g., property damage and invasion of their personal space). Therefore, platforms need to strengthen their institutions of privacy management to protect the interests of providers and maintain their commitment. By applying the micro-level psychological aspect of institutional theory, our research investigates how providers decide their level of commitment to a platform by evaluating the institutions of the platform’s privacy management. Our survey recruited 380 Airbnb providers from the Prolific panel. Structural equation modeling analysis shows that both physical and digital privacy practices strengthen providers’ legitimacy judgment of the platform’s privacy management and subsequently increase their commitment to the platform. Our theoretical contribution lies in revealing the effects of physical and digital privacy practices on B2B relationships from an institutional perspective. Our research is among the first to provide an integrative framework illustrating providers’ psychological process of legitimacy judgement. It also has practical implications for sharing economy platforms to manage privacy.The authors gratefully acknowledge the Seed Corn Funding from University of Bradford and the Research Productivity Support Scheme from Macquarie University

Amyloodinium ocellatum infestation in the broodstock of silver pompano Trachinotus blochii (Lacepede, 1801) and its therapeutic control

A case of amyloodiniosis caused by infestation of the dinoflagellate Amyloodinium ocellatum in the silver pompano (Trachinotus blochii) maintained for broodstock development is reported. Grossly, erosion of the operculum and excessive secretion of mucus on gills was observed. Microscopic examination of gill filaments showed the presence of trophonts. Histopathologically, gills showed erosion and necrosis of the primary and secondary lamellae. The causative organism A. ocellatum was identified based on the clinical signs as well as gross and microscopic examinations. Among many treatment methods tested, dip treatment with chloroquine phosphate (500 mg per 100 l of water) or with low saline water mixed with Oodinol 1000 were found useful in healthy maintenance of silver pompano broodstock

First experience in the larviculture of cobia, Rachycentron canadum (Linnaeus, 1752) in India

Cobia aquaculture has been gaining momentum internationally and has spread to more than 23 countries, half of them in the Asia-Pacific region. Envisaging the prospects of cobia farming in India, broodstock development was initiated and the first successful induced breeding was achieved in March 2010. Larviculture was experimented in Fibre Reinforced Plastic (FRP) tanks as well as Reinforced Cement Concrete (RCC) tanks and protocols were evolved. Green water technique employing the microalga, Nannochloropsis oculata was used. The critical stage for the larvae was from 5 to 9 days post-hatch (dph), when cumulative mortality reached around 90%. Enriched rotifers were fed from 3 to 10 dph and enriched Artemia nauplii from 9 to 18 dph. Weaning with larval inert feed was initiated from 18 dph and grading was carried out once in four days to avoid cannibalism. The study was conducted for 31 days and the final larval survival noted in the FRP and RCC tanks were 2 and 1%, respectively. At the end of the experiment, the specific growth rate of larvae in the FRP system was 30.1% of body weight per day, while the same in RCC tank was 28.3% of body weight per day. The low survival and specific growth rate of larvae in the RCC tanks could be attributed to the low densities of live feed maintained. The present experience indicated that cobia seed production can be successfully practised and by refining the methodology, the survival and growth can be enhanced to achieve commercial level fingerling production

Larviculture and seed production of the silver pompano, Trachinotus blochii (Lacepede, 1801) for the first time in India

Larviculture and seed production protocols for the silver pompano Trachinotus blochii, which is one of the promising finfish species for brackishwater and marine aquaculture was developed based on six trials for the first time in India. The newly hatched larvae were stocked at a density of 20 larvae l-1 in 2 t FRP tanks with 1.5 t of seawater. Green water technique was employed during larviculture upto the weaning period. Enriched S-type rotifers were fed at a density of 10-12 nos. ml-1 until 3 day post hatch (dph) and the enriched L-type rotifers were given at a density of 6-8 nos. ml-1 from 7 dph and thereafter with enriched Artemia at a density of 3-5 nos. ml-1. Weaning started from 15 dph and by 20-25 dph metamorphosis was completed. The survival on completion of metamorphosis ranged from 10-15% and the specific growth rate in terms of length (mm) was 8% per day. The larval morphology and growth pattern are also described

Broodstock development and controlled breeding of cobia Rachycentron canadum (Linnaeus 1766) from Indian seas

Cobia, Rachycentron canadum has emerged as one of the topmost finfish species for mariculture. In India, cobia broodstock was developed and induced breeding was achieved for the first time at Mandapam Regional Centre of the Central Marine Fisheries Research Institute (CMFRI). The broodstock was developed in sea cages of 6 m diameter and 3.5 m depth. Sexes were separated about two months prior to the onset of breeding season and stocked in separate cages. During March 2010, a female with intra-ovarian egg diameter of 700 μ along with two males were selected for induced spawning. The brooders were induced with human chorionic gonadotropin (hCG) at doses of 500 IU per kg body weight for female and 250 IU per kg body weight for males. Spawning was noted after 39 h of intra-muscular injection. The total eggs spawned were estimated as 2.1 million. About 90% fertilization was recorded (fertilized eggs amounted to 1.9 million). The eggs were collected using a 500 μ mesh net and stocked in incubation tanks at varying densities. The eggs hatched after 22 h of incubation at a temperature range of 28-30 ºC. The percentage of hatching was 80% and the total number of newly hatched larvae was estimated as 1.5 millio

Impact of increase in temperature and light intensity on development and metamorphosis of hatchery reared silver pompano Trachinotus blochii (Lacepede, 1801) larvae

The largehead ribbonfish, Trichiurus lepturus Linnaeus, 1758 forms a major fishery along north-west coast of India comprising the two coastal states of Gujarat and Maharashtra. Diet composition was analysed for five years (2010-2014) to understand shifts if any in the prey items. Seasonal changes in the prey items were studied for three years (2012-2014) to explore the temporal dynamics of prey availability in the ecosystem and in largehead ribbonfish guts. Feeding indices viz., Stomach fullness index (SFI), empty stomach ratio (ESR), gastrosomatic index (GaSI) and relative gut length (RLG) explained the feeding behaviour, seasonal dynamics and ontogenetic shifts in prey items. The Vacuity Index (VI) was estimated as 37.56%, indicating that T. lepturus is a carnivore and relatively edacious. Diet of T. lepturus comprised of fishes (47.16%), crustaceans (45.22%), molluscs (4.33%) and miscellaneous items (3.28%). Acetes sp. was the most dominant prey item during the study period. Feeding intensity was found to be high during the post-monsoon months which coincided with the period of gonadal maturation of the fish. Significant variations (p<0.05) were seen in the feeding indices during different months, different sizes and between sexes due to the availability of prey items, physiological changes and ontogenetic shifts. A detailed knowledge on diet composition, temporal dynamics in diet patterns and feeding indices can reveal the trophic interaction of prey-predator, resource abundance and fluctuations which are important inputs in ecology-based fishery management models/tools

Isolation and Characterization of Pathogenic Vibrio Alginolyticus from Sea Cage Cultured Cobia (Rachycentron Canadum (Linnaeus 1766)) in India

The epizootics of vibriosis caused serious economic losses to farmers. Natural blooms of the pathogen can be prevented by sea cage management measures such as, changing the inner net of the cages, changing the location of the cages to relatively clean water (about 50 m apart) from the affected site and providing shade over the cages while the water temperature rises. Supplementation of the feed with immunostimulants and mineral mixture may be practised to improve the immune response against infection. Early diagnosis and sea cage management measures may prevent occurrences of the infection

Course Manual on Marine Fisheries & Mariculture Prepared for the Training programme for B.F.Sc students of Central Agricultural University (CAU), Tripura

The undergraduate Fisheries Science students are required to know about the inland and marine fisheries. The students from landlocked area are getting rare opportunity to understand the marine fisheries and mariculture activities. Hence, based on the request of the Central Agricultural University (CAU), Tripura as a part of their academic activities, the Director, ICAR-CMFRI, has kindly approved a 10 days in-plant training for B.F.Sc. final year students at the ICAR-Central Marine Fisheries Research Institute (CMFRI), Mandapam Regional Centre. The training was organized in collaboration with Agricultural Technology Information Centre (ATIC), ICAR-CMFRI, Kochi. A total of 27 B.F.Sc students and a faculty of Central Agricultural University (CAU), Tripura participated in the training programme during 17th to 26th January, 2020. The training emphasized on the skill development of students through hands on training on mariculture activities and field visits to fish landing centres. A course manual was prepared covering the major topics on marine capture fisheries and mariculture. I congratulate all those who have put in their sincere efforts to bring out this manual