Unprecedented heavy landings of juvenile Kiddy shrimp, Parapenaeopsis stylifera along Karnataka coast

Parapenaeopsis stylifera is one of the most abundant and highly valued shrimp species in India. It forms about 20% of the penaeid shrimp catch of Karnataka with the period from January to June contributing the majority of the catch. In general, the post-monsoon months of August to December is considered as a lean period for P. stylifera. During this period single day fishing trawlers land catch of a mixture of fish, prawns, stomatopods and other crustaceans. The contribution of prawns in the catch is around 10 to 20%

Seed traits, germination pattern and seedling vigour in Antiaris toxicaria (Pers.) Lesch., a rare plant species of Western ghats

Antiaris toxicaria (Pers.) Lesch. is one of the species of ecological importance distributed in Western Ghats and other parts. This species is considered as one of the threatened species and it needs conservation. The information on fruit and seed trait variation and germination attributes are scanty. Such database is useful for afforestation programme as well as for augmentation of rare plant species in their natural habitat. For the present study, 10 open pollinated trees distributed in Devade forest of Sakharpa were marked. April month was the peak fruiting period and healthy fruits were collected from the ground. Fruit and seed traits were found to be varied significantly among trees, where fruit length ranged from 21.50 to 24.71 mm and fruit weight ranged from 3.64 to 4.07 g. Similarly, seeds length (14.01 -15.09 mm), seed thickness (12.15 -13.04 mm) and seed weight (1.20 – 1.57g) also showed significant variation among 10 trees. Field observation showed that there was a poor regeneration in this species at studied site. Therefore, germination study was conducted at nursery condition by imposing several pretreatments. Among eight treatments including control, soaking seeds in water for 24 hrs (T2) resulted in better germination of 38.0% as compared to others. In T2 seed germination started at 16 days after sowing and completed within 42 days. Potting mixture of red soil with saw dust in 30:70 ratio improved seed germination about 20 % as compared to red soil media

Seed size and its influence on germination, seedling growth and biomass in Saraca asoca (Roxb). De Wilde, critically endangered tree species of Western ghats, India

Saraca asoca (Roxb). De Wilde is one of the high traded medicinal plant species of India. There is a huge demand for bark of this species both in domestic and international markets. There is a demand for quality planting materials for large scale plantation. Forest department and farmers have already initiated captive plantation of this species. Several factors affect the seedling quality in nursery. Seed grading is one among them. The present study aims at understand the influence of seed size on seed germination and seedling vigour in S. asoca. Association study showed that seed length was positively correlated with seed weight (r= 0.887), seed width (r=0.697) and thickness (r=0.621). Therefore, seed length was used to categorize seedlot into small (< 30.0 mm), medium (30.1-40.0 mm) and large (> 40.1 mm) seeds. Result showed that larger seeds produced maximum germination (86.7%) as compared to smaller seeds (45.0%). Moreover, larger seeds attained higher collar diameter (3.34 mm) and dry biomass viz., leaf biomass (0.91 g), shoot biomass (0.31 g), root biomass (0.95 g) and entire seedling biomass (2.17 g) as compared to smaller seeds. Seedlings raised from medium seeds were at par with larger seeds in most of the traits. Therefore, it is suggested to use seedlot having > 30 mm length, preferably larger seeds (> 40 mm) in the nursery for better establishment of quality seedlings

Pure white‐light emitting ultrasmall organic‐inorganic hybrid perovskite nanoclusters

Organic–inorganic hybrid perovskites, direct band-gap semiconductors, have shown tremendous promise for optoelectronic device fabrication. We report the first colloidal synthetic approach to prepare ultrasmall (∼1.5 nm diameter), white-light emitting, organic–inorganic hybrid perovskite nanoclusters. The nearly pure white-light emitting ultrasmall nanoclusters were obtained by selectively manipulating the surface chemistry (passivating ligands and surface trap-states) and controlled substitution of halide ions. The nanoclusters displayed a combination of band-edge and broadband photoluminescence properties, covering a major part of the visible region of the solar spectrum with unprecedentedly large quantum yields of ∼12% and photoluminescence lifetime of ∼20 ns. The intrinsic white-light emission of perovskite nanoclusters makes them ideal and low cost hybrid nanomaterials for solid-state lighting applications

The Adsorption and Collapse Transitions in a Linear Polymer Chain near an Attractive Wall

We deduce the qualitative phase diagram of a long flexible neutral polymer chain immersed in a poor solvent near an attracting surface using phenomenological arguments. The actual positions of the phase boundaries are estimated numerically from series expansion up to 19 sites of a self-attracting self avoiding walk in three dimensions. In two dimensions, we calculate analytically phase boundaries in some cases for a partially directed model. Both the numerical as well as analytical results corroborate the proposed qualitative phase diagram.Comment: 8 pages, 8 figures, revte

Improving the Sensitivity of LISA

It has been shown in the past, that the six Doppler data streams obtained LISA configuration can be combined by appropriately delaying the data streams for cancelling the laser frequency noise. Raw laser noise is several orders of magnitude above the other noises and thus it is essential to bring it down to the level of shot, acceleration noises. A rigorous and systematic formalism using the techniques of computational commutative algebra was developed which generates all the data combinations cancelling the laser frequency noise. The relevant data combinations form a first module of syzygies. In this paper we use this formalism for optimisation of the LISA sensitivity by analysing the noise and signal covariance matrices. The signal covariance matrix, averaged over polarisations and directions, is calculated for binaries whose frequency changes at most adiabatically. We then present the extremal SNR curves for all the data combinations in the module. They correspond to the eigenvectors of the noise and signal covariance matrices. We construct LISA `network' SNR by combining the outputs of the eigenvectors which improves the LISA sensitivity substantially. The maximum SNR curve can yield an improvement upto 70 % over the Michelson, mainly at high frequencies, while the improvement using the network SNR ranges from 40 % to over 100 %. Finally, we describe a simple toy model, in which LISA rotates in a plane. In this analysis, we estimate the improvement in the LISA sensitivity, if one switches from one data combination to another as it rotates. Here the improvement in sensitivity, if one switches optimally over three cyclic data combinations of the eigenvector is about 55 % on an average over the LISA band-width. The corresponding SNR improvement is 60 %, if one maximises over the module.Comment: 16 pages, 10 figures, Submitted to Class. Quant. Gravit

Exact Tagged Particle Correlations in the Random Average Process

We study analytically the correlations between the positions of tagged particles in the random average process, an interacting particle system in one dimension. We show that in the steady state the mean squared auto-fluctuation of a tracer particle grows subdiffusively as $sigma^2(t) ~ t^{1/2}$ for large time t in the absence of external bias, but grows diffusively $sigma^2(t) ~ t$ in the presence of a nonzero bias. The prefactors of the subdiffusive and diffusive growths as well as the universal scaling function describing the crossover between them are computed exactly. We also compute $sigma_r^2(t)$, the mean squared fluctuation in the position difference of two tagged particles separated by a fixed tag shift r in the steady state and show that the external bias has a dramatic effect in the time dependence of $sigma_r^2(t)$. For fixed r, $sigma_r^2(t)$ increases monotonically with t in absence of bias but has a non-monotonic dependence on t in presence of bias. Similarities and differences with the simple exclusion process are also discussed.Comment: 10 pages, 2 figures, revte

Exploitation of the non-conventional bullseye fishery resource in Karnataka

The estimated average all India marine fish landings during 2012-2016 was 36,71,651 t. Of late, the catch of priacanthids has increased in commercial landings all along Indian coast. The bullseye contribution to the total production which was 0.3% in 2011 increased to 3.6% during 2016 and increased by two times from an annual average 23,031 t (2007-2011) to 45,544 t in 2012-2016. Nearly 94% production was from the west coast

Damage avoidance design steel beam-column moment connection using high-force-to-volume dissipators

Existing welded steel moment frames are designed to tolerate substantial yielding and plastic rotation under earthquake loads. This sacrificial design approach can lead to permanent, and often irreparable damage when interstory drifts exceed 2%. The experimental seismic performance of a 50% full-scale damage avoidance designed structural steel beam-column connection is presented. The beam-column joint region consists of a top flange-hung beam connected to the column by an angle bracket. High-force-to-volume (HF2V) devices are attached from the column to the beam to provide joint rigidity and energy dissipation as the joint opens and closes. The HF2V devices are connected either below the beam flange or concealed above the beam's lower flange. Reversed cyclic lateral load tests are conducted with drift amplitudes up to 4%. No damage is observed in the principal beam and column structural elements. The need for stiff device connections to achieve optimal device performance is demonstrated, and potential design solutions presented. Stable hysteresis and repeatable energy dissipation for a large number of cycles up to the 4% drift level is observed. It is concluded that superior and repeatable energy dissipation without damage can be achieved for every dynamic motion cycle, in contrast to conventional sacrificially designed welded moment frame connections