553 research outputs found

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

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    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

    Functional and Structural Investigation of Songbird Brain Projection Neurons with Shuttle and Find

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    Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7-August 11, 201

    Centrifugal fertilizer spreaders: working speed variability and quality of work

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    Characterization of the biogenic volatile organic compounds (BVOCs) and analysis of the PR1 molecular marker in Vitis vinifera L. inoculated with the nematode Xiphinema index

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    Upon pathogen attack, plants very quickly undergo rather complex physico-chemical changes, such as the production of new chemicals or alterations in membrane and cell wall properties, to reduce disease damages. An underestimated threat is represented by root parasitic nematodes. In Vitis vinifera L., the nematode Xiphinema index is the unique vector of Grapevine fanleaf virus, responsible for fanleaf degeneration, one of the most widespread and economically damaging diseases worldwide. The aim of this study was to investigate changes in the emission of biogenic volatile organic compounds (BVOCs) in grapevines attacked by X. index. BVOCs play a role in plant defensive mechanisms and are synthetized in response to biotic damages. In our study, the BVOC profile was altered by the nematode feeding process. We found a decrease in \u3b2-ocimene and limonene monoterpene emissions, as well as an increase in \u3b1-farnesene and \u3b1-bergamotene sesquiterpene emissions in nematode-treated plants. Moreover, we evaluated the PR1 gene expression. The transcript level of PR1 gene was higher in the nematode-wounded roots, while in the leaf tissues it showed a lower expression compared to control grapevines

    On-sky results of the adaptive optics MACAO for the new IR-spectrograph CRIRES at VLT

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    The adaptive optics MACAO has been implemented in 6 focii of the VLT observatory, in three different flavors. We present in this paper the results obtained during the commissioning of the last of these units, MACAO-CRIRES. CRIRES is a high-resolution spectrograph, which efficiency will be improved by a factor two at least for point-sources observations with a NGS brighter than R=15. During the commissioning, Strehl exceeding 60% have been observed with fair seeing conditions, and a general description of the performance of this curvature adaptive optics system is done.Comment: SPIE conference 2006, Advances in adaptive optics, 12 pages, 11 figure

    Meccanica agraria e zootecnia: mungitura robotizzata, analisi dei consumi energetici

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    Negli ultimi trent\u2019anni le produzioni zootecniche sono state caratterizzate da un intenso sviluppo tecnologico al quale la Meccanica Agraria ha contribuito fortemente giocando un ruolo fondamentale nell\u2019incrementare la produttivit\ue0 del lavoro, garantire e migliorare il benessere animale, assicurare un\u2019intensificazione sostenibile dei processi produttivi. L\u2019automazione delle operazioni di stalla e in particolare della mungitura, che rappresenta la fase pi\uf9 onerosa in termini economici e fisici, e per la quale non pu\uf2 ancora ritenersi concluso il processo evolutivo, \ue8 probabilmente l\u2019ambito in cui il Meccanico Agrario che opera in contesti zootecnici \ue8 maggiormente coinvolto. Ad oggi nel mondo sono installati circa 45.000 sistemi automatici di mungitura o AMS (Automatic Milking System), di cui oltre 700 in Italia, e questo numero \ue8 destinato a crescere nei prossimi anni nel contesto di una generale tendenza all\u2019automazione della stalla da latte, aumentando il consumo energetico relativo alla mungitura robotizzata. L\u2019energia utilizzata da un AMS dipende da molti fattori, tra cui la generazione di appartenenza, le configurazioni e le impostazioni della macchina, nonch\ue9 le condizioni operative. Il lavoro qui presentato ha avuto come scopo quello di misurare e analizzare il consumo elettrico di due generazioni successive di AMS installati in aziende da latte del nord Italia, caratterizzate da contesti operativi diversi. La prova sperimentale \ue8 stata condotta su quattro AMS con differenti configurazioni (stallo singolo, unit\ue0 centrale con una o due unit\ue0 di mungitura). Il consumo elettrico (giornaliero, giornaliero per bovina munta, per mungitura, per 100 litri di latte) di ogni AMS (unit\ue0 di mungitura e compressore dell\u2019aria) \ue8 stato misurato utilizzando due multimetri collegati ai quadri elettrici rispettivamente dell\u2019AMS e del compressore dell\u2019aria. Il periodo di misura \ue8 stato di 24 h per ciascun sistema, utilizzando una frequenza di campionamento di 0,2 Hz. Il consumo elettrico degli AMS \ue8 risultato condizionato principalmente dalla gestione aziendale piuttosto che dalle caratteristiche e architetture delle singole macchine

    A retrofit variable-rate control system for pressurized slurry tankers

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    n the last several decades, livestock effluent management practices and field slurry spreading operations have received increasing attention due to their economic and environmental implications. In this study, a variable-rate control system for pressurized slurry tankers was developed according a retrofit approach (i.e., as a self-standing module that can be adapted and mounted on existing slurry tanker equipment). The system provides farmers with a useful tool for achieving compliance with environmental protection regulations and for developing good practices for livestock and nitrogen management. This system is suitable for new and used pressurized tanker equipment. For field-testing purposes, this system was mounted on a double-axis 10 m3 slurry tanker equipped with a crawling nozzle distribution unit. Field experiments were conducted at two typical forward speeds (2 and 3 km h-1) and three different nitrogen application rates (170, 250, and 340 kg ha-1). Based on the experimental results, the system was generally capable of limiting the differences between the nominal and measured application rates to less than 9%. In addition, the data analysis indicated that the slurry spreading was not significantly affected by the forward speed of the tanker. The uniformity of nitrogen spreading was evaluated according to the UNI EN 13406:2002 standard. The results showed that the transverse field distribution was uniform throughout the working width of the machine and at all tested operating conditions, with maximum deviations that were limited to less than 15%

    Proposal to estimate the engine oil consumption in agricultural tractors

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    Lubrication plays a crucial role in a tractor engines' efficiency and durability. Without suitable lubrication, excessive friction will significantly reduce an engine's power, and high-intensity wear will damage the moving parts in a short period of time. A set of 178 agricultural tractor models from 20 different international manufacturers located in Europe, North America and Asia was used in this study. The tractor models were produced between 2000 and 2015 with rated engine power ranging from 30 to 428.8 kW. Rated engine power, crankcase oil capacity, and oil change intervals were derived from official test reports. Engine oil consumption was calculated using the method described in ASABE Standard D497.7, clause 3.4. A linear relationship between rated engine power and hourly oil consumption rate was confirmed, but the regression coefficients deviated from current values in the ASABE Standard. These results indicate that ASABE equation coefficients should be updated to more accurately estimate engine oil consumption for use in technical/economical evaluations and in the analysis of operating costs of new tractor models

    Naturally Derived Heme-Oxygenase 1 Inducers and Their Therapeutic Application to Immune-Mediated Diseases

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    Heme oxygenase (HO) is the primary antioxidant enzyme involved in heme group degradation. A variety of stimuli triggers the expression of the inducible HO-1 isoform, which is modulated by its substrate and cellular stressors. A major anti-inflammatory role has been assigned to the HO-1 activity. Therefore, in recent years HO-1 induction has been employed as an approach to treating several disorders displaying some immune alterations components, such as exacerbated inflammation or self-reactivity. Many natural compounds have shown to be effective inductors of HO-1 without cytotoxic effects; among them, most are chemicals present in plants used as food, flavoring, and medicine. Here we discuss some naturally derived compounds involved in HO-1 induction, their impact in the immune response modulation, and the beneficial effect in diverse autoimmune disorders. We conclude that the use of some compounds from natural sources able to induce HO-1 is an attractive lifestyle toward promoting human health. This review opens a new outlook on the investigation of naturally derived HO-1 inducers, mainly concerning autoimmunity.Fil: Funes, Samanta Celeste. Pontificia Universidad Católica de Chile; ChileFil: Rios, Mariana. Pontificia Universidad Católica de Chile; ChileFil: Fernández Fierro, Ayleen. Pontificia Universidad Católica de Chile; ChileFil: Covián, Camila. Pontificia Universidad Católica de Chile; ChileFil: Bueno, Susan M.. Pontificia Universidad Católica de Chile; ChileFil: Riedel, Claudia A.. Universidad Andrés Bello; ChileFil: Mackern Oberti, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Kalergis, Alexis M.. Pontificia Universidad Católica de Chile; Chil
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