420 research outputs found
Effect of dietary bile extracts on serum response of astaxanthin in rainbow trout (Oncorhynchus mykiss): a preliminary study
Effects of porcine bile extracts added at three different dietary
concentrations 0, 10 and 20 g kg)1 were studied on
astaxanthin serum concentration in rainbow trout (mean
weight 200 ± 7 g). Astaxanthin from micro-algae Haematococcus
pluvialis and synthetic astaxanthin (CAROPHYLL
pink) were incorporated in diets of rainbow trout
at a rate of 100 mg astaxanthin kg)1 of feed. Fish were hand
fed twice a day. After 5 days of feeding there was a significant
effect of the pigment source on the ratio (total blood
astaxanthin per unit body weight to cumulative astaxanthin
intake per unit body weight). Trout receiving synthetic
astaxanthin showed a significantly (P < 0.05) higher ratio
than trout fed algal astaxanthin. Increasing dietary bile
extract did not lead to produce any effect on this ratio. The
power of the statistical analysis is discussed. Therefore, the
interaction (pigment source · dietary bile concentration)
showed no more effect
Bennettitales, Erdtmanithecales and Gnetales from the Early Cretaceous of the Lusitanian Basin (western Portugal)
This paper presents a synthesis of the occurrence of extinct gymnosperms related to the Bennettitales, Erdtmanithecales and Gnetales group and discusses the stratigraphic setting of previously described specimens. These plants are represented by small fossil seeds collected from Lower Cretaceous (Berriasian to Lower Albian) fluvial siliciclastic deposits of the Lusitanian Basin, western Portugal, and probably constitute a monophyletic group, the BEG complex. The fossil seeds are composed of an innermost membranous nucellus preserved as a delicate cuticle. The nucellus is evolved by a membranous integument surrounded by a sclerenchymatic outer envelope. Plants from the BEG complex were contemporary of the earliest angiosperm having shared ecosystems with similar environmental characteristics, what reinforces its paleoecological importance
Evaluation of different cell disruption processes on encysted cells of Haematococcus pluvialis: effects on astaxanthin recovery and implications for bio-availability
Although Haematococcus pluvialis is one of the most importantnatural sources of the carotenoid astaxanthin as a pigmentor for theaquaculture industry, the thick sporopollenin cell wall in the cysts hindersastaxanthin extraction and its subsequent bio-availability to fish. A rangeof physical and chemical processes were tested to promote the disruptionof the encysted cells. The efficacy of these processes was evaluated interms of astaxanthin recovery, which was assessed by determining theextent of leaching of astaxanthin into an organic solvent. The processestested were: autoclave 30 min, 121 °C, 1 atm; HCl 0.1 M, 15min and 30 min; NaOH 0.1 M, 15 min and 30 min; enzymatictreatment with a mixture of 0.1% protease K and 0.5% driselase in aphosphate buffer, pH 5.8, 30 °C, for one hour; spray drying, inlet180 °C, outlet 115 °C; and mechanical disruption, with acell homogeniser developed for this purpose. The mechanical(homogenisation) and autoclave treatments were the most effective in termsof extraction and availability
A PRÁTICA DOCENTE COMO AÇÃO POLÍTICA: UM OLHAR HISTÓRICO
This article discusses contemporary educational trends regarding teaching and that points ways to teacher pedagogic practice. The objective is to make clear that the existence of these trends does not constitute a particularity of our time, but, in the contrary, that in all historical periods there have been projects aiming at finding solutions for education. However, what is now presented is a brief retrospective of modern educational proposals, after that an analysis of contemporary proposals, especially those that have appeared since the XIX century. The theme which guides our approach is the understanding of educational ideas within their historical context and, effectively,to analyze them as an expression of political trends at a given time.Este artigo tem como propósito discutir as tendências contemporâneas da Educação que apontam caminhos para a prática pedagógica do docente. O intuito é explicitar que a existências dessas tendências não constitui uma particularidade de nossa época, mas, ao contrário, em todas as épocas históricas existiram projetos buscando soluções para a educação. Contudo, o que ora se apresenta no texto é uma breve retrospectiva de propostas educativas na modernidade para, em seguida, analisarmos com vagar, as contemporâneas, especificamente aquelas que surgiram a partir do século XIX. O fio condutor que norteia nossa abordagem é o entendimento das idéias educacionais dentro de seu contexto histórico e, efetivamente, analisá-las como expressão de tendências políticas de um dado momento
The influence of light and culture media on the growth of the red seaweed Gracilaria gracilis (Rhodophyta, Gracilariales) under laboratory conditions
info:eu-repo/semantics/publishedVersio
Notes on mating behaviour and a possible new host plant for megacyllene angulata (Fabricius, 1775) (cerambycidae, coleoptera)
The mating behavior of M. angulata (Fabricius, 1775) is described, illustrated and discussed. Additionally, we also comment on the possible new host plant of this species based on two plants (Luehea cymulosa Spruce ex Benth. (Malvaceae) and Doliocarpus dentatus (Aubl.) Standl (Dilleniaceae) on which copulation occurs. © 2020, Universidade de Sao Paulo. All rights reserved
Reproduction of the blue jack mackerel, Trachurus picturatus, in western Portugal: microscopic gonad analysis reveals indeterminate fecundity and skipped spawning patterns
Blue jack mackerel, Trachurus picturatus, is the fifth most landed fish species in mainland Portugal, but
information on its reproductive biology is scarce. From September 2018 to August 2019, 626 specimens
were collected from commercial vessels to clarify the reproductive strategy of the T. picturatus population
off the west coast of Portugal. The proportion and length range of males and females were similar. Only
three of the specimens collected were categorized as immature, indicating that the fish caught in the
fishery are primarily mature. The spawning season lasted from late January until the end of March, with
gonadosomatic indices being similar for males and females. Fecundity was indeterminate, and estimated
batch fecundity ranged between 6,798 (at 25.4 cm TL) and 302,358 oocytes (at 33.8 cm TL). The low
number of females showing direct evidence of imminent or recent spawning suggests a low number
of spawning events. In addition, 12.7% of females were considered non-reproductive due to ovary
abnormalities including parasitic infection by Kudoa species, atretic structures and skipped spawning
events. This study highlights the importance of accounting for skipped spawning events and ovary
abnormalities in the management of species fisheries.info:eu-repo/semantics/publishedVersio
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