889 research outputs found
Nota. Presencia de Listeria spp. en trucha asalmonada (Onchorhyncus mykiss) y salmón (Salmo salar)
Salmon-trout (Onchorhyncus mykiss) and salmon (Salmo salar) are the main raw materiaIs in the
cold-smoked fish industry. It is important to prevent the contamination of these ready-to-eat
products with Listeria monocytogenes and other (Listeria spp.) because the temperature used in the
cold-smoking process is not sufficient to inactivate these organisms. The presence of Listeria spp.
and L. monocytogenes in the cold-smoked salmon and salmon-trout processing chains of three
Portuguese factories examined was already confirmed in previous studies. Thus, it was important
to ascertain the possible sources of contamination, the raw material being the most important one.
AlI the Portuguese cold-smoking fish factories use fresh salmon-trout from two trout farms in the
north of Portugal and Norwegian salmon which arrives by lorry every week under refrigeration,
imported always by the same company; 88 samples of salmon and salmon-trout were analysed;
67 environrnental samples from the two trout farms were also examined. The overalI frequency
(n =40) of Listeria spp. and L. monocytogenes in salmon was 12 and 0% respectively. The overalI
frequency (n =48) of Listeria spp. and L. monocytogenes in salmon-trout was 6.3 and 2.1% respectively.
Listeria was not found in the environmental samples
Characterization of Listeria monocytogenes isolated from production lines of fresh and cold-smoked fish
Aims: The aims of this study were to characterize strains of Listeria monocytogenes isolated from cold-smoking fish plants to establish possible routes of contamination through the processing chain.
Methods and Results: Listeria monocytogenes from fresh fish suppliers, raw materials, factory sites and finished products isolated in Portugal (162 isolates) and England (28 isolates) were characterized by serotyping, phage typing, tetracycline, cadmium and arsenic resistance, and plasmid profiling. On the basis of serotyping and phage typing, the isolates were categorized into eight groups. Although cultures within some of the groups could be further differentiated on the basis of plasmid profiling and cadmium and arsenite typing, consideration of all typing data predominantly clustered together isolates from a single location. L. monocytogenes strains: from fresh salmon suppliers were not found in the processing lines; from fresh salmon from different locations differed; and from the water where salmon trout were farmed differed from those isolated from the fish samples.
Significance and Impact of the Study: No clear source or route of contamination in the cold-smoked processing chain could be established; however, these results highlight the complexity in tracking this bacterium through food chains
Actividades experimentais no Jardim-de-Infância: projecto aprender e gostar de aprender ciências
A comunicação apresentada diz respeito a um trabalho realizado com crianças e educadoras.
Esse trabalho faz parte de um Projecto mais amplo, “Aprender e Gostar de Aprender Ciências”, que envolveu também crianças e professoras do 1º Ciclo do Ensino Básico. O Projecto, que decorreu no ano lectivo 2006/2007 e foi financiado pelo Programa Ciência Viva VI “Ensino Experimental das Ciências na Escola”, teve como grandes finalidades a implementação de um
programa de actividades experimentais para crianças e a aquisição de materiais para as
escolas e os jardins-de-infância.
A comunicação descreve o impacto do Projecto nas crianças, essencialmente em termos de
desenvolvimento de capacidades sócio-afectivas, como a autonomia e a responsabilidade, e de construção e/ou aprofundamento de conhecimento. Descreve também a avaliação que as educadoras fizeram do Projecto, bem como o impacto deste no seu desenvolvimento profissional e nas crianças.
O Projecto desenvolveu-se num concelho desfavorecido do meio rural, o Concelho de Vinhais, distrito de Bragança e ocorreu em três fases: na primeira ajudaram-se as
educadoras/professoras a implementar actividades de ciências concebidas e organizadas pelos formadores. Na segunda fase ajudaram-se as educadoras/professoras a conceber e a explorar outras actividades experimentais, contribuindo para o seu desenvolvimento profissional. Na terceira fase avaliou-se o impacto do Projecto junto das crianças e das educadoras/professoras.
Pela análise dos dados colhidos no decorrer do Projecto, com base na opinião das crianças e num conjunto de registos efectuados pelas crianças e pelas educadoras, pode-se afirmar que foi notória a motivação e o empenho com que participaram nas actividades; por outro lado, pensamos que o Projecto contribuiu para o desenvolvimento de competências por parte das
crianças
Kalman Filtering in the Air Quality Monitoring
Data assimilation is a process where an improved prediction is obtained from a weighted combination between experimental measurements and mathematical model data. In the present work this procedure is applied to pollutant atmospheric dispersion by using a Kalman filter (KF). This is interesting approach, because the KF gives an output in which the balance between the data from the diffusion model and the experimental data is done automaticaly, through the Kalman gain. In addition, the Kalman filter computes the propagation of the error
Aprender a gostar de aprender ciências
Com o projecto que aqui se apresenta, pretende-se promover a realização de
actividades experimentais de ciências por crianças do 1ºCiclo do Ensino Básico
(CEB) e do Jardim-de-infância (JI). O projecto desenvolver-se-á em 3 fases: na
1ª ajudam-se os professores e os educadores a implementar actividades de ciências concebidas e organizadas pelos formadores. Na 2ª fase ajudam-se os professores a educadores a conceber e a explorar outras actividades
experimentais, contribuindo para o seu desenvolvimento profissional. Na 3ª fase
avalia-se o impacto do projecto junto das crianças e dos professores.Escola Superior de Educação de Braganç
Avaliação de ensaios preliminares de linhagens de soja de 2. ano.
bitstream/item/133863/1/ID10310-1984-1985sojaresultados-p29-42.pdfTrabalho apresentado na XIII Reunião de Pesquisa de Soja da Região Sul, Porto Alegre, 1984
Production of annual ryegrass with different doses of nitrogen fertilization in topdressing.
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Previous issue date: 2019bitstream/item/207926/1/SeminaCiAg-Mittelmann-Production.pd
The effect of feed supplementation with inulin on boar taint levels and meat quality of entire male pigs
Received: March 19th, 2022 ; Accepted: May 3rd, 2022 ; Published: July 5th, 2022 ; Correspondence: [email protected] and androstenone are the two main compounds responsible for the foul odour
in entire male pigs’ meat, known as boar taint. This study evaluated the effect of feed
supplementation with inulin on the boar taint levels of 30 entire male pigs. Two months before
slaughter, the animals were allocated into three groups (n = 10). The control group received a
standard commercial diet. The other groups were fed the same commercial diet with 3% and 6%
added inulin, respectively. Results showed that inulin addition to the feed significantly reduced
skatole levels in the pigs’ adipose tissue compared with the control group. The levels of
androstenone were not affected by the dietary approach. Although there were differences in some
parameters, the supplementation with inulin did not promote extensive changes in the meat
quality parameters between the tested groups. When raising entire males, supplementation with
inulin in finishing diets could be considered to reduce the boar taint perception by the consumer
A model based on Heisenberg’s theory for the eddy diffusivity in decaying turbulence applied to the residual layer
The problemof the theoretical derivation of a parameterization for the eddy diffusivity in decaying turbulence is addressed. This derivation makes use of the dynamical equation for the energy spectrum density and the classical statistical diffusion theory. The starting point is Heisenberg’s elementary decaying turbulence theory. The main assumption is related to the identification of a frequency, lying in the inertial subrange, characterizing the inertial energy transfer among eddies of different size. The resulting eddy diffusivity parameterization is then applied to the decay of convective turbulence in the residual layer. Besides the intrinsic scientific
interest, this topic has relevance for mesoscale transport and diffusion simulations. The resulting expression for the eddy diffusivity cannot be solved analytically. For this reason an algebraic approximated formulation, giving nearly the same results as the exact expression, is also proposed
Level-of-Detail Triangle Strips for Deforming Meshes
Applications such as video games or movies often contain deforming
meshes. The most-commonly used representation of these types of meshes consists in dense polygonal models. Such a large amount of
geometry can be efficiently managed by applying level-of-detail techniques
and specific solutions have been developed in this field. However,
these solutions do not offer a high performance in real-time applications.
We thus introduce a multiresolution scheme for deforming meshes.
It enables us to obtain different approximations over all the frames of
an animation. Moreover, we provide an efficient connectivity coding by means of triangle strips as well as a flexible framework adapted to the GPU pipeline. Our approach enables real-time performance and, at the same time, provides accurate approximations
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