Semi-intensive production of Penaeus vannamei in Guatemala

SUMMARY Because marine shrimp species convenient for aquacultural purposes live mainly in warm-water environments, commercial shrimp farms are located principally along tropical and sub-tropical marine coastlines. Other than the South-East Asiatic countries, the Latin America countries are important shrimp producers that contribute in satisfying the international demand of marine shrimp. Part of the imported shrimp in Italy come from Guatemala, where the shrimp aquaculture (representing around the 88% of the total aquaculture production) is based mainly on the Pacific white shrimp (Penaeus vannamei). Common rearing procedures of one of the biggest marine shrimp farms operating in Guatemala are described. Some productive parameters of Penaeus vannamei brought out by semi-intensive system in earthen ponds are quantified. Productive data result in a uniform distribution of weight classes at different days after stocking, besides the growth trend and feed conversion ratio agree with the growth performance of Penaeus vannamei. Growth data, fitted on the von Bertalanffy model, present the maximum weight gain (0.13 g/day) 28 days after stocking. Shrimp survival after a grow-out period of 80 days in a 2.44-ha pond is around 56% and the gross yield turns out to be more than one ton per hectare. In conclusion, semi-intensive shrimp farming performed in Guatemala allows to have high productivities as well as a good quality product. On the other hand it must be highlighted that this kind of cultivation represents a risk for the environmental equilibrium along the coasts of tropical countries. RIASSUNTO Poiché le specie di gambero marino utilizzate a fini produttivi sono originarie principalmente degli ambienti con acqua a temperatura elevata, le aziende che producono questi gamberi sono situate maggiormente lungo le coste dei Paesi tropicali e sub-tropi- cali. Oltre ai Paesi del Sud-Est Asiatico, i Paesi dell’America Latina sono importanti produttori, che contribuiscono a soddisfare la domanda internazionale di gamberi marini. Parte dei gamberi importati in Italia proviene dal Guatemala, dove la produzione di gamberi, che rappresenta l’88% della produzione nazionale di acquacoltura, è basata principalmente sul gambero bianco del Pacifico (Penaeus vannamei). Vengono descritte le comuni procedure produttive di una delle più grandi aziende di gamberi marini operanti in Guatemala. Vengono inoltre valutati alcuni parametri produttivi del Penaeus vannamei, allevato con un sistema semi-intensivo all’interno dei bacini di questa azienda. I dati di peso risultano distribuiti uniformemente alle diverse epoche dopo la semina, inoltre l’andamento dei pesi e l’indice di conversione alimentare concordano con i parametri di crescita del Penaeus vannamei. I dati di crescita, stimati con il modello proposto da von Bertalanffy, evidenziano il massimo incremento di peso (0,13 g al giorno) al 28° giorno dalla semina. La sopravvivenza dei gamberi dopo un periodo di accrescimento di 80 giorni in un bacino di 2,44 ettari è di circa il 56% e la resa supera il quantitativo di una tonnellata per ettaro. Nel complesso l’allevamento di gamberi con sistema semiintensivo, condotto in Guatemala, sembra fornire un’alta produttività combinata con una buona qualità del prodotto finale. D’altronde deve essere considerato che questo sistema d’allevamento rappresenta un serio rischio per l’equilibrio ambientale lungo le coste dei paesi tropicali

Aplicación de elementos finitos en la predicción del factor de intensidad de esfuerzos para fisuras en modo abertura

Se expone la importancia del criterio KIC en Fractomecánica y su campo de aplicabilidad. Se indican Las Limitaciones de la formulación analítica. Se proponen dos criterios de evaluación de K1 en base al Método de Elementos Finitos: el Criterio del Promedio de Valores y el Criterio del Intercepto. Se entregan resultados para ambos criterios aplicados a tres especímenes finitos, incluyendo una evaluación de cada criterio

In vivo characterisation of a therapeutically relevant self-assembling 18 F-labelled β-sheet forming peptide and its hydrogel using positron emission tomography

Positron emission tomography (PET) and fluorescence labelling have been used to assess the pharmacokinetics, biodistribution and eventual fate of a hydrogel-forming nonapeptide, FEFKFEFKK (F9) in healthy mice, using 18F-labelled and fluoresceinisothiocyanate (FITC) - labelled F9 analogues. F9 was site-specifically radiolabelled with 2-[18F]fluoro-3-pyridinecarboxaldehyde ([18F]FPCA) via oxime bond formation. [18F]FPCA-F9 in vivo fate was evaluated both as a solution, following intravenous administration, and as a hydrogel when subcutaneously injected. The behaviour of FITC-F9 hydrogel was assessed following subcutaneous injection. [18F]FPCA-F9 demonstrated high plasma stability and primarily renal excretion; [18F]FPCA-F9 when in solution and injected into the bloodstream displayed prompt bladder uptake (53.4 ± 16.6 SUV at 20 minutes post injection) and rapid renal excretion, whereas [18F]FPCA-F9 hydrogel, formed by co-assembly of [18F]FPCA-F9 monomer with unfunctionalised F9 peptide and injected subcutaneously, showed gradual bladder accumulation of hydrogel fragments (3.8 ± 0.4 SUV at 20 minutes post injection), resulting in slower renal excretion. Gradual disaggregation of the F9 hydrogel from the site of injection was monitored using FITC-F9 hydrogel in healthy mice (60 ± 3 over 96 hours), indicating a biological half-life between 1-4 days. The in vivo characterisation of F9, both as a gel and a solution highlights its potential as a biomaterial

Host-parasite relationships in root-knot disease of white mulberry

Severe infections of white mulberry feeder roots and heavy soil infestations by Meloidogyne arenaria race 2 were found in southern Spain. This is the first record of M. arenaria on white mulberry in Europe. Morphometric observations, analysis of the esterase electrophoretic pattern, and artificial inoculations of race differentials were used to characterize nematodes. Nematode-induced mature galls were spherical and usually contained one or more females, males, and egg masses with eggs. Feeding sites were characterized by the development of giant cells that contained granular cytoplasm and many hypertrophied nuclei. Giant cell cytoplasm was aggregated along a thickened cell wall. Vascular tissues within galls appeared disorganized. The relationship between the initial nematode population density (Pi) in a series from 0 to 1,024 eggs and juveniles/cm3 soil and growth of white mulberry seedlings was tested in the greenhouse. A Seinhorst model was fitted to plant height and top fresh weight. Tolerance limits of white mulberry to M. arenaria race 2 for plant height and top fresh weight were, respectively, 1.1 and 1.38 eggs and juveniles/cm3 soil. The minimum relative values for plant height and top fresh weight were 0 at Pi > 64 and Pi > 128 eggs and juveniles/cm3 soil, respectively. Maximum nematode reproduction rate was 435-fold at the lowest Pi. Additional keywords: histopathology, Morus alba, pathogenicity, threshold limitPeer reviewe

Swift J201424.9+152930: discovery of a new deeply eclipsing binary with 491 s and 3.4 h modulations

We report on the discovery of a new X-ray pulsator, Swift J201424.9+152930 (Sw J2014). Owing to its X-ray modulation at 491 s, it was discovered in a systematic search for coherent signals in the archival data of the Swift X-ray Telescope. To investigate the nature of Sw J2014, we performed multi-wavelength follow-up observations with space-borne (Swift and XMM-Newton) and ground-based (the 1.5-m Loiano Telescope and the 3.6-m Telescopio Nazionale Galileo) instruments. The X-ray spectrum of Sw J2014 can be described by a hard and highly absorbed power law. The optical observations made it possible to single out the optical counterpart to this source, which displays several variable emission lines and total eclipses lasting ~20 min. Total eclipses of similar length were observed also in X-rays. The study of the eclipses, allowed us to infer a second periodicity of 3.44 h, which we interpret as the orbital period of a close binary system. We also found that the period has not significantly changed over a ~7 yr timespan. Based on the timing signatures of Sw J2014, and its optical and X-ray spectral properties, we suggest that it is a close binary hosting an accreting magnetic white dwarf. The system is therefore a cataclysmic variable of the intermediate polar type and one of the very few showing deep eclipses.Comment: 12 pages, 8 figures, 5 tables; minor changes to match the final MNRAS versio

Encyclopedia of psychopharmacology

Definition of microiontophoresis and related methods as found in the Encyclopedia of Psychopharmacology.peer-reviewe

Innovative Mars Global International Exploration (IMaGInE) mission

This paper presents the conceptual design of the IMaGInE (Innovative Mars Global International Exploration) Mission whose mission objectives are to deliver a crew of four astronauts to the surface of Deimos and a robotic exploration mission to Phobos for approx-imately 343 days during the years 2031 and 2032, perform surface excursions, technology demonstrations, and In Situ Resource Utilization (ISRU) of the Martian moons as well as site reconnaissance for future human exploration of Mars. This is the winning mission design of the 2016 Revolutionary Aerospace Systems Concepts-Academic Linkage (RASC-AL) competition, awarded with the "Best in Theme," "Best Overall," and "Pio-neering Exceptional Achievement Concept Honor (PEACH)" prizes. This competition was sponsored by NIA and NASA

Strangeness and Quark Gluon Plasma

A brief summary of strangeness mile stones is followed by a chemical non-equilibrium statistical hadronization analysis of strangeness results at SPS and RHIC. Strange particle production in AA interactions at \sqrt{s_{NN}}\ge 8.6 GeV can be understood consistently as originating from the deconfined quark--gluon plasma in a sudden hadronization process. Onset of QGP formation as function of energy is placed in the beam energy interval 10--30A GeV/c. Strangeness anomalies at LHC are described.Comment: 30 pages including numerouse figures, tables. Opening Lecture: Strangeness and Quark Gluon Plasma -- what has been learned so far and where do we go at SQM2003, North Carolina, March 2003, submitted to J. Phys.

Landau-Zener-Stuckelberg interferometry

A transition between energy levels at an avoided crossing is known as a Landau-Zener transition. When a two-level system (TLS) is subject to periodic driving with sufficiently large amplitude, a sequence of transitions occurs. The phase accumulated between transitions (commonly known as the Stuckelberg phase) may result in constructive or destructive interference. Accordingly, the physical observables of the system exhibit periodic dependence on the various system parameters. This phenomenon is often referred to as Landau-Zener-Stuckelberg (LZS) interferometry. Phenomena related to LZS interferometry occur in a variety of physical systems. In particular, recent experiments on LZS interferometry in superconducting TLSs (qubits) have demonstrated the potential for using this kind of interferometry as an effective tool for obtaining the parameters characterizing the TLS as well as its interaction with the control fields and with the environment. Furthermore, strong driving could allow for fast and reliable control of the quantum system. Here we review recent experimental results on LZS interferometry, and we present related theory.Comment: 34 single-column pages, 11 figure