Development of giant freshwater prawn broodstock

The commercial success of a giant freshwater prawn (Macrobrachium rosenbergii) hatchery depends upon the uninterrupted supply of the desired quantity and quality of broodstock. This study was an attempt to develop the broodstock near a hatchery, to be used for seed production throughout the year. The hatchery produced seed were stocked at the rate of 3/m2 after initial pond preparation. The prawns were fed with a pelleted diet (3 mm size) prepared by using locally available feed ingredients. The seed had an initial weight of 0.30 g and attained an average weight of 92.0 g and 62.0 g in males and females, respectively, within 11 months. Berried prawns were observed starting from the month of June (5%), after six months of stocking, with a maximum in September (60%). The percentage of berried prawns increased from June to September when the water temperature was optimum and decreased from December when it got cold. The broodstock developed in this experiment could be used in the hatchery after six months of stocking, and brooders could be used to produce seed for two seasons before being sold in the market

Non Timber Forest Products and Biodiversity Conservation - A Study of Tribals in a Protected Area in India

This study analyses the economics of Non Timber Forest Products (NTFPs) and the economic values appropriated by tribals in a protected area in India. Using primary data covering a cross section of tribals in the Nagarhole National Park (NNP), South India the stud y notes that the economic values appropriated by the tribals are quite high. Even after including external costs (i.e. wildlife damages costs and defensive expenditures to protect against wildlife attacks) the Net Present Value of NTFP benefits derived by the tribal households was over Rs 30,378 per household (at 12% discount rate for cash flows summed over 25 years). Interestingly when the external costs borne by third parties (i.e., coffee growers) are taken into account the net NTFP benefits turned negative. In other words, although from the NTFP extractors viewpoint NTFP extraction is a viable activity, from the society's viewpoint this is not so. The estimated net NTFP benefits from NNP after including the external costs borne by NTFP extractors was estimated at between USD 33.5 to 167.5 per ha per year using alternate assumptions regarding the park's catchment area. The tribals have a positive attitude towards biodiversity conservation. Asked to justify and rank the reasons why biodiversity needs to be conserved, the tribals emphasized its livelihood and ecosystem fun ctions. Using contingent valuation method, the study notes that those with income from coffee estates and forest employment, and those residing in the core zone of the national park are less willing to accept compensation and relocate outside the national park. The study suggests improving the incentive structure in order to obtain the support and participation of tribals in biodiversity conservation strategies.Non Timber Forest Products, Biodiversity Conservation, Net Present Values, External Costs, Contingent Valuation Method, Resource /Energy Economics and Policy,

The role of response mechanisms in determining reaction time performance: Piéron’s Law revisited

A response mechanism takes evaluations of the importance of potential actions and selects the most suitable. Response mechanism function is a nontrivial problem that has not received the attention it deserves within cognitive psychology. In this article, we make a case for the importance of considering response mechanism function as a constraint on cognitive processes and emphasized links with the wider problem of behavioral action selection. First, we show that, contrary to previous suggestions, a well–known model of the Stroop task (Cohen, Dunbar, & McClelland, 1990) relies on the response mechanism for a key feature of its results—the interference–facilitation asymmetry. Second, we examine a variety of response mechanisms (including that in the model of Cohen et al., 1990) and show that they all follow a law analogous to Piéron's law in relating their input to reaction time. In particular, this is true of a decision mechanism not designed to explain RT data but based on a proposed solution to the general problem of action selection and grounded in the neurobiology of the vertebrate basal ganglia. Finally, we show that the dynamics of simple artificial neurons also support a Piéron–like law

THE ECONOMICS OF BIODIVERSITY CONSERVATION-A STUDY IN A COFFEE GROWING REGION OF INDIA

This paper analyses the economics of biodiversity conservation in the context of a tropical ecosystem in India, where coffee is the main competitor for land use.Using primary data covering a cross section of coffee growers,the study notes that the opportunity costs of biodiversity conservation in terms of coffee benefits foregone are quite high.Even after including external costs due to wild life damages and defensive expenditures to protect against wild life, the NPVs and IRRs from coffee for all land holding groups were high.The study notes that the external costs accounted for between 7 to 15% of the total discounted costs of coffee cultivation, and smaller holdings proportionately incurred higher external costs as compared to larger holdings. The study also notes high transaction costs incurred by the growers to claim compensation for wild life damages. Notwithstanding these disincentives, the study notes that the local community were willing to pay in terms of time for participatory biodiversity conservation, and they preferred a decentralised government institution for this purpose.Resource /Energy Economics and Policy,

On the phase diagram of 2d Lorentzian Quantum Gravity

The phase diagram of 2d Lorentzian quantum gravity (LQG) coupled to conformal matter is studied. A phase transition is observed at $c=c_{\rm crit}$ ($1/2<c_{\rm crit}<4$) which can be thought of as the analogue of the $c=1$ barrier of Euclidean quantum gravity (EQG). The non--trivial properties of the quantum geometry are discussed.Comment: LATTICE99(gravity), 3 pages, espcrc2.sty, simulations available at http://www.nbi.dk/~ambjorn/lqg2

Synthesis, characterization and curing studies of thermosetting epoxy resin with amines

A new hybrid thermosetting maleimido epoxy compound 4-(N-maleimidophenyl) glycidylether (N-MPGE) is prepared by reacting N-(4-hydroxyphenyl) maleimide (HPM) with Epichlorohydrin by using benzyltrimethylammonium chloride as a catalyst. The resulting compound possesses both the oxirane ring and maleimide group. The curing reaction of these maleimidophenyl glycidylether epoxy compound (N-MPGE) with amines as curing agents such as ethylendiamine (EDA), diethylentriamine (DETA) and triethylenetetramine (TETA), aminoethylpiperazine (AEP) and isophoronediamine, IPDA), are studied. Incorporation of maleimide groups in the epichlorohydrin provides cyclic imide structure and high cross-linking density to the cured resins. The cured samples exhibited good thermal stability, excellent chemical (acid/alkali/solvent) and water absorption resistance. Morphological studies by the SEM technique further confirmed the phase homogeneity net work of the cured systems

Making the gravitational path integral more Lorentzian, or: Life beyond Liouville gravity

In two space-time dimensions, there is a theory of Lorentzian quantum gravity which can be defined by a rigorous, non-perturbative path integral and is inequivalent to the well-known theory of (Euclidean) quantum Liouville gravity. It has a number of appealing features: i) its quantum geometry is non-fractal, ii) it remains consistent when coupled to matter, even beyond the c=1 barrier, iii) it is closer to canonical quantization approaches than previous path-integral formulations, and iv) its construction generalizes to higher dimensions.Comment: 4 pages, 2 figures (postscript), uses espcrc2.st

Mechanistic aspects for the oxidation of sunset yellow dye by chloramine-T in presence of perchloric acid and in sodium hydroxide medium catalyzed by Os(VIII): A spectrophotometric kinetic approach

The kinetics of oxidation of sunset yellow (SY) by sodium-N-chloro-p-toluenesulfonamide or chloramine-T (CAT) was studied spectrophotometrically in HClO4 and NaOH media with Os(VIII) as a catalyst in the latter medium at 298 K and 303 K, respectively. In acid medium, the experimental rate law is -dCAT/dt = kCAT0SY0HClO4-0.46. Alkali accelerates the rate of reaction and the rate law takes the form -dCAT/dt = kCAT0SY0NaOH0.23OsO40.84. The solvent isotope effect was studied using D2O. Benzenesulfonic acid and 1,2-naphthoquinone-6-sulfonic acid were characterized as the oxidation products of SY. Under identical set of experimental conditions in alkaline medium, Os(VIII) catalyzed reaction is about seven-fold faster than the uncatalyzed reaction. Activation parameters for the overall reaction and also with respect to catalyst have been evaluated. The observed results have been explained by plausible mechanisms and the related rate laws have been deduced. © 2008 Elsevier B.V. All rights reserved