Horizontal target strength-size conversion equations for sea bass and gilt-head bream

[EN] Horizontal hydroacoustics is a technique of remote fish detection that has proved to efficiently determine fish density and biomass in shallow or superficial waters. This non-intrusive technique could render better results than those obtained by conventional sampling when monitoring shallow waters. To apply this technique, we need equations that relate the amount of sound returned by fish, known as target strength (TS in dB), with their length (mm) or weight (g). This study presents horizontal conversion equations for the species gilt-head bream (Sparus aurata) and sea bass (Dicentrarchus labrax), two of the most important species bred in aquaculture. Moreover, this study presents a new formula to calculate a mixed equation adjusted to the percentage of distribution of those species in case of mixed populations. The results in this research have been obtained by applying a simple setup that allows for high-quality acoustic data. These new equations will enable the application of this technique in order to estimate these species' density and biomass in shallow aquatic systems such as aquaculture ponds with semi-intensive production densities.This study's authors would like to thank the Superintendent of Economy and Knowledge (Andalusian Government) for the funding provided as part of the project (PI_57052) developed in collaboration with CTAQUA. We would like to thank the researchers Carlos Orduna Marin and Juan Ramon Cid Quintero for their selfless work to obtain the field data and to the company PIMSA for generously allowing us to use their facilities and fish. We would also like to thank the veterinarian JR Rodriguez for being kind enough to perform X-rays on the studied fish and Cristina Ocana for her careful proofreading of the English text.Rodríguez-Sánchez, V.; Rodríguez-Ruiz, A.; Pérez Arjona, I.; Encina-Encina, L. (2018). Horizontal target strength-size conversion equations for sea bass and gilt-head bream. Aquaculture. 490:178-184. https://doi.org/10.1016/j.aquaculture.2018.02.034S17818449

Keys for designing hematite/plasmonic metal hybrid nanostructures with enhanced photoactive properties

Photoactive hybrid nanostructures composed of metal oxides and plasmonic metals are able to perform the conversion of radiant (solar) energy into electrical or chemical energy. However, their use in large-scale practical applications still requires their photoconversion efficiency to be improved. In this work, the light-harvesting properties of hematite/plasmonic metal rodlike hybrid nanostructures are investigated on the basis of discrete dipole approximation simulations. The effects of the length and nature of the metallic counterpart on the far- and near-field optical properties of the hybrid nanostructure are analyzed in detail. The implemented methodology allowed us to assess the contribution of each component of the hybrid nanostructure to the absorption efficiency, Qabs, separately. In turn, the Qabs values obtained were employed to determine the absorbed photon flux, ø, within the α-Fe2O3 component, a relevant quantity directly related to the photoconversion efficiency. It was found that both absorption efficiency Qabs and absorbed photon flux ø can be largely enhanced through a proper selection of the length and nature of the metallic counterpart of the nanostructure, evidencing plasmon-enhanced light absorption in the α-Fe2O3 component, which is attributed to a plasmon-induced energy transfer mechanism based on near-field enhancements. Importantly, it was found that the highest ø values achieved for nanostructures composed of Ag and Al (∼11 × 1016 photons cm-2 s-1) are nearly 3 times larger than those corresponding to nanostructures composed of Au (∼4 × 1016 photons cm-2 s-1). In addition, a direct relationship between the absorbed photon flux, ø, and optical characteristics of the nanostructures, that is, the bandgap energy of α-Fe2O3 and the energy and radiative line width of the localized surface plasmon resonance, was empirically obtained. Such a relationship not only complements but also overcomes the limitations of the reported useful criteria and provides helpful guidelines for the optimum design of hybrid nanostructures with enhanced photoactive properties.Fil: Encina, Ezequiel Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Coronado, Eduardo A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentin

Reproductive capacity of the red cusk-eel genypterus chilensis (Guichenot, 1848) in captivity

Indexación: Scopus.This work was supported by the FONDEF Project D06I 1024 “Development of technologies for the production of red cusk-eel fingerlings (Genypterus chilensis)”.Genypterus chilensis is a marine fish of high gastronomic demand, whose capture has declined in recent years due to overfishing. In the development of the farming technology, high mortalities were obtained during egg incubation. The objective of this study is to contribute to the knowledge of fecundity and eggs viability of G. chilensis in captivity. The spawns of G. chilensis were analyzed over a period of 2 years and 3 months. The total fecundity was estimated by counting the masses and eggs produced monthly throughout the period. The results confirm that G. chilensis is a partial spawner, since a female may more than two masses of eggs per day, due to a large amount of mass spawned per season (621 average). The total production of masses of the Farming Centre during the period was 2,290; of these, only 7% (166) corresponding to 15,330,517 eggs were incubated. Because of its high fecundity, G. chilensis produces numerous masses of eggs, of which only a small percentage reaches incubation, as well as it occurs in other marine fish. © 2018, Escuela de Ciencias del Mar. All rights reserved.https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0718-560X201800020048

Enfoque a los principales procedimientos en el D. E. M.

97 p.Como la incorporación del Departamento de Educación a la gestión municipal es muy reciente ,adolece - como es lógico - de algún grado de improvisación entre sus procedimientos, no llegando aún a estructurarse dentro de su Administración una total complementación con los principios básicos de control que rigen a los Municipios. Es por este motivo que parece ser un organismo total y absolutamente autónomo, cuando en la realidad es y debe ser parte integral de todo el quehacer municipal. Viendo que un poco las cosas se hacen " de memoria”, este trabajo pretende ser un primer paso para insertar dentro de los municipios un Sistema de Cursogramas tendiente a agilizar el desarrollo de los procedimientos internos y simplificar la exposición de tales operaciones ante posibles fiscalizaciones por intermedio del Ministerio del interior o de Contraloría General de la República, ya que representan una fotografía del Sistema de Control Interno que debe estar guiado al resguardo eficiente de los recursos del Estado. Mayor importancia adquiere esta idea si consideramos que el Sistema de Cursogramas a través del Departamento de Educación puede ser útil para todos los innumerables procedimientos municipales, y así no dejar a las Unidades de Control trabajando en base a eventuales aciertos o errores administrativos, sin haber dado la pauta que guíe las operaciones, para poder, efectivamente, ser ella un control de controles como teórica y prácticamente debe trabajar una Unidad de Control o Auditoria interna

Exploring high temperature magnetic order in CeTi_1-xSc_xGe

Most of magnetic transitions related to Ce ordering are found below T_ord~12K. Among the few cases exceeding that temperature, two types of behaviors can be distinguished. One of them is related to the rare cases of Ce binary compounds formed in BCC structures, with a quartet ground state, whose degeneracy is reduced by undergoing different types of transitions mostly structural. The other group shows evidences of itinerant character with the outstanding example of CeRh_3B_2 showing the highest T_ord=115K. The second highest ordering temperature has been reported for CeScGe with T_ord=47K, but the nature of this magnetic state has not been investigated very deeply. In order to shed more light into this unusual high temperature ordering we studied the structural, magnetic, transport and thermal properties of CeTi_1-xSc_xGe alloys in the stability range of the CeScSi-type structure 0.25<x<1 This system presents a rich variety of magnetic behaviors along this concentration range, with the magnetic ordering growing from ferromagnetic (FM) T_C~7K up to an antiferromagnetic (AFM) transition at T_N=47K. The different regions show the following characteristics: i) on the Ti rich side (0.25<x<0.50) it exhibits a FM ground state (GS) with large saturation magnetization values M_sat up to ~1.15 mu_B. ii) Around x=0.60, the first crystal electric field excited doublet starts to contribute to the GS magnetic properties. Furthermore an AFM component with a connected metamagnetic transition appears. iii) At x=0.65 a clear change in the GS nature is associated to a critical point above which the GS properties can be described like for an itinerant system (with decreasing M_sat) and an effective GS degeneracy N_eff=4. iv) For x>0.65, the magnetic phase boundary splits into two transitions, with an intermediate phase presenting incommensurate spin density waves features.Comment: 8 pages, 10 figure

Tuberculosis, microbios, tuberculina : Apuntes y experimentos

Índice - célula é individuo - la enfermedad - el bacilo de Koch - orígen de los microbios - especies atacadas - vías de introducción - los fagocitos - génesis del tubérculo - inmunidad y predisposición - tuberculina - experimentos - conclusiones - apéndice - bibliografíaAl momento de la presentación de esta tesis, la actual Facultad de Ciencias Veterinarias se denominaba Facultad de Agronomía y Veterinaria de la provincia de Buenos Aires.Material digitalizado en SEDICI gracias al Museo de Anatomía Veterinaria "Dr. Víctor Manuel Arroyo" de la UNLP.Facultad de Ciencias Veterinaria

Quenching of excited carbonyl triplets by benzene derivatives

Se ha medido la velocidad de desactivación de tripletes carbonilicos (biacetilo, bencilo, benzofenona y 4-metil-2-pentanona) por una serie d,e derivados del benceno. Los resultados pueden ser interpretados por un mecanismo de transferencia de carga. Los compuestos con hidrógenos lábiles (i.e.cumeno) muestran una mayor reactividad. La abstracción de hidrógeno ocurre desde el complejo de transferencia de carga. La desactivación del triplete de la 4-metil-2-pentanona fue medida entre - 5 y 70°C. Las energias de activación obtenidas variaron entre 8.1 kcal (para el cumeno) y 10 kcal (para el benceno)