Structural Stability and Level Density of Hot Rotating Doubly Magic Isotopes of Calcium

The recently reported doubly-magic nuclei 52Ca and 54Ca are discussed in comparison with the other magic isotopes of Calcium. the temperature effect is included in this study and hence the statistical approach to obtain the particle emission and level density are discussed in the context of temperature effect. We predict an increase in neutron emission for 54Ca due to the abrupt decrease in neutron separation energy around t=0.4MeV. Since the drop in the separation energy is closely associated with the structural changes in the rotating nuclei, relative increase in neutron emission probability around certain values of temperature may be construed as evidence for the shape transition. Such effects are not obtained for 40,48,52Ca isotopes. hence this statistical study reveals the higher stability of magic nature of 52Ca than 54Ca, against temperature

Taxonomy and Distribution of Scleria foliosa (Cyperaceae) in Kerala, India

Scleria foliosa (Cyperaceae) an interesting sedge species is reported here as a new record for Kerala. Detailed description with photographs and relevant notes on distribution are provided for easy identification

A brackishwater isolate of Pseudomonas PS-102, a potential antagonistic bacterium against pathogenic vibrios in penaeid and non-penaeid rearing systems

A Pseudomonas sp PS-102 recovered from Muttukkadu brackish water lagoon, situated south of Chennai, showed significant activity against a number of shrimp pathogenic vibrios. Out of the 112 isolates of bacterial pathogens comprising Vibrio harveyi, V. vulnificus, V. parahaemolyticus, V. alginolyticus, V. fluvialis, and Aeromonas spp, 73% were inhibited in vitro by the cell-free culture supernatant of Pseudomonas sp PS-102 isolate. The organism produced yellowish fluorescent pigment on King's B medium, hydrolysed starch and protein, and produced 36.4% siderophore units by CAS assay and 32 μM of catechol siderophores as estimated by Arnow's assay. The PS-102 isolate showed wide ranging environmental tolerance with, temperatures from 25 to 40 °C, pH from 6 to 8, salinity from 0 to 36 ppt, while the antagonistic activity peaked in cultures grown at 30 °C, pH 8.0 and at 5 ppt saline conditions. The antagonistic activity of the culture supernatant was evident even at 30% v / v dilution against V. harveyi. The preliminary studies on the nature of the antibacterial action indicated that the antagonistic principle as heat stable and resistant to proteolytic, lipolytic and amylolytic enzymes. Pseudomonas sp PS 102 was found to be safe to shrimp when PL-9 stage were challenged at 107 CFU ml− 1 and by intramuscular injection into of 5 g sub-adults shrimp at 105 to 108 CFU. Further, its safety in a mammalian system, tested by its pathogenicity to mice, was also determined and its LD50 to BALB/c mice was found to be 109 CFU. The results of this study indicated that the organism Pseudomonas sp PS 102 could be employed as a potential probiont in shrimp and prawn aquaculture systems for management and control of bacterial infections

Enhanced production of lupeol through elicitation in in vitro shoot cultures of snake grass (Clinacanthus nutans)

Clinacanthus nutans (Acanthaceae), generally known as ‘snake grass’, has diverse uses in customary system of herbal medicine. The species is endowed with various bioactive compounds exhibiting extensive pharmacological properties. The present investigation focused on elicitor-intervened in vitro shoot biomass cultivation and scale-up production of the anti-cancerous compound ‘lupeol’, one of the foremost constituents in this species. For the augmented production of lupeol, the shoot cultures were elicited with various concentrations of yeast extract (YE), chitosan and methyl jasmonate (MeJA). Maximum shoot biomass yield and production of lupeol was detected in MS medium supplemented with 1.0 mgl-1 BA and 400 mgl-1 YE. The petroleum ether extracts of selected samples upon TLC analysis proved Rf values corresponding to lupeol. HPTLC analysis revealed that the sample treated with YE displayed relatively higher amount (975.50 ng) of lupeol than the in vivo plant (713.69 ng). Hence the in vitro shoot culture system with elicitor (YE) treatment propose an appropriate method for the elevated synthesis of lupeol which can be scaled up via bio-reactor technology in doing so profiting the pharmaceutical appliances

Stock structure analysis of oil sardine Sardinella longiceps (Valenciennes, 1847) from southeast and southwest coasts of India

A total of 200 specimens of oil sardine Sardinella longiceps collected from Kochi in the southwest coast and Chennai in the southeast coast were subjected to truss analysis. A truss network was constructed by interconnecting 10 landmarks to form a total of 21 truss distance variables extracted from the landmarks. The transformed truss measurements were subjected to factor analysis which revealed that there is no separation of the stocks along southeast and southwest coasts. The marginal differences in shape and form are attributed to the ecological differences in the habitats which is evident from differences in length weight relationships and feeding intensity of the population along these two coasts

Stock structure analysis of Indian mackerel Rastrelliger kanagurta (Cuvier, 1817) from south-east and south-west coasts of India using truss network system

A total of 200 specimens of Indian mackerel (Rastrelliger kanagurta) were collected from Kochi in the south-west coast and Chennai in the south-east coast and they were subjected to truss analysis. A truss network was constructed by interconnecting 10 landmarks to form a total of 21 truss distance variables extracted from the landmarks. The transformed truss measurements were subjected to factor analysis which revealed that there is no separation of the stocks along south-east and south-west coasts. Thus the present study has indicated that the population of Indian mackerel from south-east and south-west coasts remains the same

Inter-annual variations of selected oceanographic parameters and its relation to fishery of small pelagics off Kochi, southwest coast of India

The availability as well as abundance of selected small pelagics along Kerala coast (south west coast of India) was highly variable during the past three decades. During the period 1980-2012 there have been several periods of abundance as well as population crashes in the oil sardine fishery. The present study revealed that the occurrence of low sea level during the month of May implies either early wind driven upwelling or early intensification of equator-ward coastal current and consequent upsloping of isopycnals. The occurrence of low sea level (6857) as early as in May and upwelled water in August with low dissolved oxygen (0.68 ml l-1) with low sea water temperature (24˚C) at the bottom at 10 m depth, off Kochi was found to affect the sardine fishery in the year 1994, when the landing at Kochi was only 15 t. Mean sea level was found to be a sign of upwelling and the real time observations of dissolved oxygen indicated wide variations during the upwelling period

Overfishing and Climate Drives Changes in Biology and Recruitment of the Indian Oil Sardine Sardinella longiceps in Southeastern Arabian Sea

The recent fluctuations in abundance of the Indian oil sardine Sardinella longiceps, a tropical small pelagic clupeid fish, was investigated in the light of overfishing and variations in its habitat ecology in southeastern Arabian Sea. In 2012, its landings peaked to an all-time record making it the fifth largest sardine fishery in the world, and within 3 years the catches were reduced to nearly a tenth of that level. This study examined the fishery dependant factors such as effort, catch rates and expansion of fishing area; the biological variations in fish size, maturity and recruitment; and tried to relate this to the environmental variations in the sardine habitat and food availability. The 2012 mega harvest was a result of a 2-time increase in gear size and engine capacity of fishing crafts and a 3.7-time increase in fishing effort. The female maturation process was strongly influenced primarily by rainfall and then by upwelling and the resulting influx of cold nutrient-rich water in the habitat from April much before the start of the monsoon in June. After 2013, the weak monsoons and the 2015 El Nino Southern Oscillation resulted in a warmer (by an average of 1.1°C) period which negatively impacted the maturation process. The abundance of jellyfishes which are larval and young fish predators in the habitat negatively affected recruitment after 2013. The mismatch in timing of phytoplankton productivity and sardine larvae in the habitat also affected the recruitment success. These environmental divergences coupled with the excessive capture (beyond maximum sustainable yields) of spawning stock and juveniles from 2010 has resulted in this biological catastrophe which has affected the livelihood of thousands of small-scale fishers. A more responsive fisheries administration with timely restriction on fishing effort and protection of spawning stocks by way of fishery closure would have helped minimize the impacts