A numerical study of the longitudinal thermoconvective rolls in a mixed convection flow in a horizontal channel with a free surface

This paper presents a numerical study of three-dimensional laminar mixed convection within a liquid flowing on a horizontal channel heated uniformly from below. The upper surface is free and assumed to be flat. The coupled Navier-Stokes and energy equations are solved numerically by the finite volume method taking into account the thermocapillary effects (Marangoni effect). When the strength of the buoyancy, thermocapillary effects and forced convective currents are comparable $(Ri\backsimeq O(1)$ and $Bd=Ra/Ma \backsimeq O(1))$, the results show that the development of instabilities in the form of steady longitudinal convective rolls is similar to those encountered in the Poiseuille-Rayleigh-B\'enard flow. The number and spatial distribution of these rolls along the channel depend on the flow conditions. The objective of this work is to study the influence of parameters, such as the Reynolds, Rayleigh and Biot numbers, on the flow patterns and heat transfer characteristics. The effects of variations in the surface tension with temperature gradients (Marangoni effect) are also considered

Offspring subcutaneous adipose markers are sensitive to the timing of maternal gestational weight gain

peer-reviewedBackground Excessive maternal weight gain during pregnancy impacts on offspring health. This study focused on the timing of maternal gestational weight gain, using a porcine model with mothers of normal pre-pregnancy weight. Methods Trial design ensured the trajectory of maternal gestational weight gain differed across treatments in early, mid and late gestation. Diet composition did not differ. On day 25 gestation, sows were assigned to one of five treatments: Control sows received a standard gestation diet of 2.3 kg/day (30 MJ DE/day) from early to late gestation (day 25–110 gestation). E sows received 4.6 kg food/day in early gestation (day 25–50 gestation). M sows doubled their food intake in mid gestation (day 50–80 gestation). EM sows doubled their food intake during both early and mid gestation (day 25–80 gestation). L sows consumed 3.5 kg food/day in late gestation (day 80–110 gestation). Offspring body weight and food intake levels were measured from birth to adolescence. Markers of lipid metabolism, hypertrophy and inflammation were investigated in subcutaneous adipose tissue of adolescent offspring. Results The trajectory of gestational weight gain differed across treatments. However total gestational weight gain did not differ except for EM sows who were the heaviest and fattest mothers at parturition. Offspring birth weight did not differ across treatments. Subcutaneous adipose tissue from EM offspring differed significantly from controls, with elevated mRNA levels of lipogenic (CD36, ACACB and LPL), nutrient transporters (FABP4 and GLUT4), lipolysis (HSL and ATGL), adipocyte size (MEST) and inflammation (PAI-1) indicators. The subcutaneous adipose depot from L offspring exhibited elevated levels of CD36, ACACB, LPL, GLUT4 and FABP4 mRNA transcripts compared to control offspring. Conclusions Increasing gestational weight gain in early gestation had the greatest impact on offspring postnatal growth rate. Increasing maternal food allowance in late gestation appeared to shift the offspring adipocyte focus towards accumulation of fat. Mothers who gained the most weight during gestation (EM mothers) gave birth to offspring whose subcutaneous adipose tissue, at adolescence, appeared hyperactive compared to controls. This study concluded that mothers, who gained more than the recommended weight gain in mid and late gestation, put their offspring adipose tissue at risk of dysfunction.This research was funded by Teagasc, under the National Development Plan. LBMcN was in receipt of a Teagasc Walsh Fellowship. Nestle hosted LG on a sabbatical and funded the RT-PCR cost

An evaluation of the Limited Repair Program of the Winnipeg Home Improvement Project by the Institute of Urban Studies

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Retail market prices of fonio reveal the demand for quality characteristics in Bamako, Mali.

African consumers' expectations concerning quality of food products are great. In spite of constrained budgets, we showed that market retailed prices revealed quality preferences of the consumers and not only production costs. In very poor countries like Mali, food innovation is limited by the very low purchasing power of the population. However, technological food product or process innovations are possible and sometimes valuable. Demand driven innovation may lead to open new markets, opportunities for small and medium scale enterprises and to improve consumers' welfare. Based on this assumption, technical research was done to provide new food products. In this paper, using both sensory test and a hedonic price approach, we estimated consumer demand for different characteristics of fonio, a West African cereal, and showed that poor consumers do have quality requirements and actually pay for it. We showed that the shadow or hedonic price paid for quality characteristics is small but significant. A comparison of sensory test and market study showed a convergence between what people say they prefer and what they really pay for. Results were consistent and showed directions for technological improvement of the product and its production process. The Partial Least Square method was used to estimate hedonic prices of the different modalities of fonio quality traits.Demand and Price Analysis,

Produção de serapilheira em sistemas agroflorestais em Tomé-Açu, Amazônia Oriental.

A deposição de serapilheira representa um elo fundamental no fluxo de carbono entre o meio físico e o biótico, conferindo ao ecossistema do qual faz parte maior estabilidade, variando de acordo com o seu estágio sucessional e o tipo de sistema utilizado. O objetivo deste trabalho consistiu em realizar um estudo do fluxo de carbono pela deposição de serapilheira de quatro sistemas agroflorestais (SAFs) com idades e composições diferentes, no município de Tomé-Açu, Pará. O fluxo de carbono foi medido na deposição de material formador de serapilheira no período de um ano. Os SAFs foram divididos em quatro categorias, denominados SAF 1, SAF 2, SAF 3 e SAF 4, sendo (SAF 1: cacau, açaí, bananeira e seringueira, 14 anos de idade, SAF 2: cacau, açaí, bananeira, seringueira, taperebá, paricá e macacaúba, 14 anos de idade, SAF 3: cupuaçu, açaí, teca e mogno, 9 anos de idade, SAF 4:cupuaçu, açaí e paricá, 9 anos de idade). Em cada sistema, foram instaladas quatro parcelas amostrais, e dentro das parcelas foram instalados coletores para medir a deposição de material formador de serapilheira. O SAF 4 teve a maior deposição de serapilheira anual entre todos os tratamentos. A produção mensal de serapilheira apresentou uma distribuição diferenciada ao longo do ano. A estação seca foi caracterizada pela maior produção de serapilheira em todos os tratamentos. A quantidade de carbono depositada via litterfall difere significativamente em sistemas agroflorestais com idades e composições diferentes. Existe também diferença significativa entre meses dentro de um mesmo tratamento.Editores técnicos: Roberto Porro, Milton Kanashiro, Maria do Socorro Gonçalves Ferreira, Leila Sobral Sampaio e Gladys Ferreira de Sousa

Retail market prices of fonio reveal the demand for quality characteristics in Bamako, Mali

Les attentes des consommateurs africains concernant la qualité de l'alimentation sont importantes malgré des budgets très contraints. Nous montrons ici que les prix de marchés révèlent des préférences qualitatives et non seulement des coûts de production. Dans des pays très pauvres come le Mali, l'innovation technologique est limitée par le très faible pouvoir d'achat de la population. Cependant les innovations technologiques sont possibles et parfois payantes. L'innovation en réponse à une demande peut permettre d'ouvrir de nouveaux marchés, de donner des opportunités aux petites et moyennes entreprises et d'améliorer le bien-être des consommateurs. Sur la base de cette hypothèse, la recherche technologique s'applique à fournir de nouveaux produits. Dans cet article, en utilisant à la fois des tests de dégustation et une analyse des prix hédoniques, nous estimons la demande des consommateurs pour différentes caractéristiques du fonio, une céréale d'Afrique de l'Ouest. Nous montrons que des consommateurs pauvres ont des exigences de qualité et paient de fait pour les satisfaire. Nous montrons que les prix hédoniques ou shadow prices payés pour les caractéristiques qualitatives sont faibles mais significatifs. La comparaison des tests sensoriels et de l'étude de marché montre une convergence entre ce que les gens disent et ce pour quoi ils paient réellement. Les résultats sont cohérents et montrent des directions pour l'amélioration technologique des produits et des procédés de transformation. La méthode des moindres carrés ordinaires a été utilisée pour l'estimation des prix hédoniques des différentes modalités des attributs de qualité du fonio. Cette méthode est intéressante car elle résout les problèmes de colinéarité

Retail Market Prices of Fonio Reveal The Demand For Quality Characteristics in Bamako, Mali

African consumers' expectations concerning the quality of food products are great. In spite of constrained budgets, we showed that market retail prices revealed quality preferences of the consumers and not just production costs. In very poor countries like Mali, food innovation is limited by the very low purchasing power of the population. However, technological food product or process innovations are possible and sometimes valuable. Demand driven innovation may lead to open new markets, opportunities for small and medium scale enterprises and to improve consumers' welfare. Based on this assumption, technical research was done to provide new food products. In this paper, we used both sensory tests and a hedonic price approach, to estimate the consumers' demand for different characteristics of fonio, a West African cereal, and showed that poor consumers have quality requirements and pay for them. We showed that the shadow price or hedonic price paid for quality characteristics is small but significant. A comparison between sensory tests and a market study showed a convergence between what people say they prefer and what they really pay for. Results were consistent and showed directions for technological improvement of the product and its production process. The partial least square method was used to estimate hedonic prices of the different modalities of fonio quality traits. This method was interesting since it solved the ordinary least square method's colinearity problems. ...French Abstract : Les attentes des consommateurs africains concernant la qualité de l'alimentation sont importantes malgré des budgets très contraints. Nous montrons ici que les prix de marchés révèlent des préférences qualitatives et non seulement des coûts de production. Dans des pays très pauvres comme le Mali, l'innovation technologique est limitée par le très faible pouvoir d'achat de la population. Cependant les innovations technologiques sont possibles et parfois payantes. L'innovation en réponse à une demande peut permettre d'ouvrir de nouveaux marchés, de donner des opportunités aux petites et moyennes entreprises et d'améliorer le bien-être des consommateurs. Sur la base de cette hypothèse, la recherche technologique s'applique à fournir de nouveaux produits. Dans cet article, en utilisant à la fois des tests de dégustation et une analyse des prix hédoniques, nous estimons la demande des consommateurs pour différentes caractéristiques du fonio, une céréale d'Afrique de l'Ouest. Nous montrons que des consommateurs pauvres ont des exigences de qualité et paient de fait pour les satisfaire. Nous montrons que les prix hédoniques ou shadow prices payés pour les caractéristiques qualitatives sont faibles mais significatifs. La comparaison des tests sensoriels et de l'étude de marché montre une convergence entre ce que les gens disent et ce pour quoi ils paient réellement. Les résultats sont cohérents et montrent des directions pour l'amélioration technologique des produits et des procédés de transformation. La méthode des moindres carrés ordinaires a été utilisée pour l'estimation des prix hédoniques des différentes modalités des attributs de qualité du fonio. Cette méthode est intéressante car elle résout les problèmes de colinéarité.FONIO; CEREAL; QUALITY; HEDONIC PRICES; PLS METHOD; EMPIRICAL INVESTIGATION

Soil contamination following an industrial accident : towards efficient investigations and assessment

International audienceWhen an industrial accident occurs, e.g. the explosion or the fire of a chemical facility, soil investigations and subsequent risk mitigation generally need to be decided and performed rapidly. This requires specific organisation and tools: Procedures for an immediate and coordinated intervention of relevant actors: industrials, administrations for industrial facilities, emergency and health, local authorities, environmental consultants and laboratories, NGOs. Models and input data on emission, atmospheric transfer and deposition on soil, for an accidental source; investigation plans and adequate soil quality references, guidelines... But the European Seveso legislation, and its application in France and probably in Europe, is focused on the prevention of immediate impacts on health and constructions; and the Integrated Pollution Prevention and Control (IPPC) legislation deals with the chronic impacts of operating facilities. Thus, post-accidental impacts of industrial accidents are hardly dealt with, the specific organisation and tools are lacking, and when accidents occur, the industrials and administrations concerned are largely unprepared for managing their delayed impacts, first of them on soils

Estimated Number of Birds Killed by House Cats (Felis catus) in Canada

Predation by house cats (Felis catus) is one of the largest human-related sources of mortality for wild birds in the United States and elsewhere, and has been implicated in extinctions and population declines of several species. However, relatively little is known about this topic in Canada. The objectives of this study were to provide plausible estimates for the number of birds killed by house cats in Canada, identify information that would help improve those estimates, and identify species potentially vulnerable to population impacts. In total, cats are estimated to kill between 100 and 350 million birds per year in Canada (> 95% of estimates were in this range), with the majority likely to be killed by feral cats. This range of estimates is based on surveys indicating that Canadians own about 8.5 million pet cats, a rough approximation of 1.4 to 4.2 million feral cats, and literature values of predation rates from studies conducted elsewhere. Reliability of the total kill estimate would be improved most by better knowledge of feral cat numbers and diet in Canada, though any data on birds killed by cats in Canada would be helpful. These estimates suggest that 2-7% of birds in southern Canada are killed by cats per year. Even at the low end, predation by house cats is probably the largest human-related source of bird mortality in Canada. Many species of birds are potentially vulnerable to at least local population impacts in southern Canada, by virtue of nesting or feeding on or near ground level, and habitat choices that bring them into contact with human-dominated landscapes where cats are abundant. Because cat predation is likely to remain a primary source of bird mortality in Canada for some time, this issue needs more scientific attention in Canada

The retail market prices of fonio reveal the demand for quality characteristics in Bamako, Mali.

African consumers' expectations concerning quality of food products are great. In spite ofconstrained budgets, we showed that market retailed prices revealed quality preferences of theconsumers and not only production costs. In very poor countries like Mali, food innovation islimited by the very low purchasing power of the population. However, technological food productor process innovations are possible and sometimes valuable. Demand driven innovation may lead toopen new markets, opportunities for small and medium scale enterprises and to improve consumers'welfare. Based on this assumption, technical research was done to provide new food products. Inthis paper, using both sensory test and a hedonic price approach, we estimated consumer demandfor different characteristics of fonio, a West African cereal, and showed that poor consumers dohave quality requirements and actually pay for it. We showed that the shadow or hedonic price paidfor quality characteristics is small but significant. A comparison of sensory test and market studyshowed a convergence between what people say they prefer and what they really pay for. Resultswere consistent and showed directions for technological improvement of the product and itsproduction process. The Partial Least Square method was used to estimate hedonic prices of thedifferent modalities of fonio quality traits. This method was interesting since it solved the OrdinaryLeast Square method's colinearity problems