Study on biology of Thryssa dussumieri (Valenciennes, 1848) from the coast of Ratnagiri, Maharashtra, India

The Dussumier’s thryssa, Thryssa dussumieri is one of the important component of by-catch of trawl and mini purse seine landings at Ratnagiri. The length-weight relationship indicated the isometric growth in T. dussumieri with generalized equation W = 0.0066 L 3.1077. The month-wise relative condition factor showed two peaks coinciding with peak spawning season. All morphometric lengths showed varying degree of correlation with total length. The qualitative and quantitative analysis of food revealed Thryssa dussumieri to be a carnivore, feeding mainly on mysids, copepods, diatoms and juvenile shrimps.The highest GSI value, for females, was observed during March, October, December and January. The male:female ratio was found to be 1:1.4. T. dussumieri has got a prolonged spawning season extending from September to April. The absolute fecundity ranged from 3367 to 14130 eggs with an average of 7420 eggs. Length at sexual maturity has been estimated to be 12.8 cm

The BRICS in the Global Order: A New Political Agenda?

Regarding the BRICS (Brazil, Russia, India, China and South Africa) it’s important to analyze comparatively the new power cycle in order to understand not only the impact of the world crisis as well as the relationship between the official political discourses and the economic instability. Actually, the trade liberalization and economic interdependence accompanied with an uncertain international system are putting pressure to the BRICS with their own agendas for global order in seeking for a balance and also to regain a new political and economical dynamic for the promotion of new strategies

Pity for economically disadvantaged groups motivates donation and ally collective action intentions

We argue that pity can motivate collective action intentions toward groups that are both politically and economically deprived. We tested this connection in four online surveys and an experiment. In Study 1 (N = 1,007), pity for the Roma in Hungary predicted collective action intentions, which was replicated in Study 2 in connection with refugees in Germany (N = 191) and in Hungary (N = 563). Study 3 (N = 475) demonstrated that for not economically but politically disadvantaged groups (e.g., sexual minorities), pity was not a predictor of ally action. In an experiment (Study 4, N = 447), pity was just as strong a predictor of collective action intentions as outrage on behalf of an economically and politically disadvantaged outgroup. Pity can be a mobilizing emotion when it comes to groups that are both economically and politically disadvantaged; however, outrage remains more important in the absence of economic hardship

Protein Phosphatase 2A Controls Ethylene Biosynthesis by Differentially Regulating the Turnover of ACC Synthase Isoforms

The gaseous hormone ethylene is one of the master regulators of development and physiology throughout the plant life cycle. Ethylene biosynthesis is stringently regulated to permit maintenance of low levels during most phases of vegetative growth but to allow for rapid peaks of high production at developmental transitions and under stress conditions. In most tissues ethylene is a negative regulator of cell expansion, thus low basal levels of ethylene biosynthesis in dark-grown seedlings are critical for optimal cell expansion during early seedling development. The committed steps in ethylene biosynthesis are performed by the enzymes 1-aminocyclopropane 1-carboxylate synthase (ACS) and 1-aminocyclopropane 1-carboxylate oxidase (ACO). The abundance of different ACS enzymes is tightly regulated both by transcriptional control and by post-translational modifications and proteasome-mediated degradation. Here we show that specific ACS isozymes are targets for regulation by protein phosphatase 2A (PP2A) during Arabidopsis thaliana seedling growth and that reduced PP2A function causes increased ACS activity in the roots curl in 1-N-naphthylphthalamic acid 1 (rcn1) mutant. Genetic analysis reveals that ethylene overproduction in PP2A-deficient plants requires ACS2 and ACS6, genes that encode ACS proteins known to be stabilized by phosphorylation, and proteolytic turnover of the ACS6 protein is retarded when PP2A activity is reduced. We find that PP2A and ACS6 proteins associate in seedlings and that RCN1-containing PP2A complexes specifically dephosphorylate a C-terminal ACS6 phosphopeptide. These results suggest that PP2A-dependent destabilization requires RCN1-dependent dephosphorylation of the ACS6 C-terminus. Surprisingly, rcn1 plants exhibit decreased accumulation of the ACS5 protein, suggesting that a regulatory phosphorylation event leads to ACS5 destabilization. Our data provide new insight into the circuitry that ensures dynamic control of ethylene synthesis during plant development, showing that PP2A mediates a finely tuned regulation of overall ethylene production by differentially affecting the stability of specific classes of ACS enzymes

Distinct mechanisms for aerenchyma formation in leaf sheaths of rice genotypes displaying a quiescence or escape strategy for flooding tolerance

Background and Aims Rice is one of the few crops able to withstand periods of partial or even complete submergence. One of the adaptive traits of rice is the constitutive presence and further development of aerenchyma which enables oxygen to be transported to submerged organs. The development of lysigenous aerenchyma is promoted by ethylene accumulating within the submerged plant tissues, although other signalling mechanisms may also co-exist. In this study, aerenchyma development was analysed in two rice (Oryza sativa) varieties, ‘FR13A’ and ‘Arborio Precoce’, which show opposite traits in flooding response in terms of internode elongation and survival. Methods The growth and survival of rice varieties under submergence was investigated in the leaf sheath of ‘FR13A’ and ‘Arborio Precoce’. The possible involvement of ethylene and reactive oxygen species (ROS) was evaluated in relation to aerenchyma formation. Cell viability and DNA fragmentation were determined by FDA/FM4-64 staining and TUNEL assay, respectively. Ethylene production was monitored by gas chromatography and by analysing ACO gene expression. ROS production was measured by using Amplex Red assay kit and the fluorescent dye DCFH2-DA. The expression of APX1 was also evaluated. AVG and DPI solutions were used to test the effect of inhibiting ethylene biosynthesis and ROS production, respectively. Key Results Both the varieties displayed constitutive lysigenous aerenchyma formation, which was further enhanced when submerged. ‘Arborio Precoce’, which is characterized by fast elongation when submerged, showed active ethylene biosynthetic machinery associated with increased aerenchymatous areas. ‘FR13A’, which harbours the Sub1A gene that limits growth during oxygen deprivation, did not show any increase in ethylene production after submersion but still displayed increased aerenchyma. Hydrogen peroxide levels increased in ‘FR13A’ but not in ‘Arborio Precoce’. Conclusions While ethylene controls aerenchyma formation in the fast-elongating ‘Arborio Precoce’ variety, in ‘FR13A’ ROS accumulation plays an important role