976 resultados para EMIGRACION E INMIGRACION - BOLIVIA - 1997-2008
Resumo:
Leuconostoc spp. are lactic acid bacteria (LAB) implicated in food spoilage, especially on refrigerated, modified atmosphere packaged (MAP) meats. The overall aim of this thesis was to learn more about Leuconostoc spp. as food spoilage organisms with a focus on commercial products where LAB spoilage is considered a problem and the main factor limiting shelf-life. Therefore, we aimed to identify Leuconostoc spp. involved in food spoilage, as well as to characterise the spoilage reactions they caused and their contamination sources during poultry meat processing. In addition, we examined the distribution of strains of Leuconostoc gasicomitatum in different food commodities. Finally, we analysed the genome content of L. gasicomitatum LMG 18811 with a special focus on metabolic pathways related to food spoilage. The findings show that Leuconostoc gelidum and L.gasicomitatum were responsible for the discoloration and off-odours developed in beef steaks. Together with Leuconostoc mesenteroides, these Leuconostoc spp., also cause spoilage of vegetable sausages. In contrast, we showed that Leuconostoc spp. are not important for the shelf-life or quality of non-marinated broiler products although, in marinated broiler fillet products, Leuconostoc spp., L.gasicomitatum in particular, are considered spoilage organisms. Furthermore, the findings of the contamination survey we carried out in a poultry processing plant indicated that spoilage Leuconostoc spp. are derived from the processing environment rather than from the broilers, and that air movement distributes psychrotrophic spoilage LAB, including leuconostocs, and has an important role in meat contamination during poultry processing. Pulsed-field gel electrophoresis (PFGE) based genotyping of L. gasicomitatum strains demonstrated that certain genotypes are common in various meat products. In contrast, genotypes associated with meat were not recovered in vegetable-based sources. This suggests that these two food categories either become contaminated with, or favour the growth of different genotypes. Furthermore, the results indicated that the meat processing environment contributes to L. gasicomitatum contamination as certain genotypes were repeatedly identified from products of the same processing plant. Finally, the sequenced and annotated genome of L.gasicomitatum LMG 18811 allowed us to identify the metabolic pathways and reactions resulting in food spoilage.
Resumo:
O presente trabalho se propõe a identificar sentidos de ensino médio, ensino técnico e trabalho do professor que se atualizam no embate entre ensino para o trabalho e ensino médio, no Colégio Técnico da Universidade Rural do Rio de Janeiro. Um breve histórico sobre o ensino técnico no Brasil e sobre a história do CTUR foi traçado, a fim de entender possíveis raízes do conflito entre o ensino para o trabalho e o ensino médio. Para ouvir os professores falarem sobre o seu trabalho, optamos pela entrevista como um dispositivo metodológico, a fim de dar voz ao docente do CTUR, de modo que fosse possível ter acesso a textos sobre o embate não disponíveis em outras circunstâncias. (ROCHA, DAHER, SANTANNA, 2004). O aporte teórico desta pesquisa se fundamenta nos pressupostos da Análise do Discurso, no que se refere à concepção de prática discursiva e subjetividade (MAINGUENEAU, 1997, 2008, 2011); e no que concerne ao trabalho, na perspectiva ergológica (SCHWARTZ, 1997, 2010), em particular, os conceitos de experiência, trabalho, normas antecedentes e renormalizações. Para a análise dos fragmentos construídos a partir das falas dos professores, usamos os estudos de Koch (2011) sobre as modalidades do discurso; a heterogeneidade enunciativa, segundo Authier-Revuz (1990), e a negação polêmica, conforme Ducrot (1987). As análises nos levaram a refletir sobre alguns embates presentes nas falas dos professores, como, por exemplo, as especificidades do trabalho, o ensino para a academia ou para o mercado e a valorização do ensino médio. As conclusões apontam para a possibilidade da abertura de um debate relacionado às questões históricas, políticas e filosóficas sobre o embate ensino médio/ensino técnico a fim de contribuir para o entendimento das funções dos sujeitos no CTUR
Resumo:
渤海湾沿岸人口密集,工农、航运发达,渤海自身净化能力非常有限。因此,渤海湾 环境污染的压力越来越大,主要污染物包括重金属和持久性有机污染物的。四角蛤蜊广泛 分布于渤海湾海域,是一种重要的经济贝类,对污染物具有较强的富集能力。为了研究不 同站点渤海湾四角蛤蜊软体部重金属含量,选择大港油田、高沙岭码头、涧河村三个断面 进行研究,对不同站点四角蛤蜊软体部重金属含量进行了分析和讨论,最后对水生动物的 POPs 毒理调控通道进行了探索性研究,得到以下结果: 1. 通过比较渤海不同站点四角蛤蜊软体部重金属含量分布特征和方差分析,发现四 角蛤蜊软体部必需重金属元素含量较高,而非必需重金属元素含量较低,这是由于必需重 金属元素具有重要的生理功能作用。侧重比较A、B 两个断面各站位间四角蛤蜊软体部重 金属含量,发现虽然各站位间分布规律不明显,但各站位间差异显著。 2. 利用简单相关回归分析金属元素间及其与生物学性状间的关系,发现Mn 与Zn 之 间,Cu 与Zn 间均存在显著正相关,Se 与As、Cd 间存在显著正相关。另外,A 断面,BL 与Cd 含量显著负相关其回归方程为:Y(Cd)=-1395.97+88.34(BL);R=0.633;在B 断面,利用BW 和BH 分别与Cd 和As 显著负相关和显著正相关,其回归方程分别为:BW 和Cd 的回归方程为:Y(Cd)=-1968.80+220.72(BW);R=0.656。BH 和As 的回归方 程为:Y(As)=1496.86+227.82(BH);R=0.656。 3. 利用PLS(偏最小二乘分析)方法分析,发现五个生物学性状都与Co、As 呈正相 关,而与Cr、Pb、Se 呈负相关,而与必须重金属元素相关不明显。进一步分析表明表明 渤海湾海域中Co、As 含量低于四角蛤蜊正常生长发育的需要,而Cr、Pb、Se 的含量超过 四角蛤蜊正常生长发育所需的量。最后,通过PLS-DA 分析方法,发现C 站点样品能与A、 B 两个断面的站点区分开,而A、B 间未能区分开,反映了渤海湾三个断面的实际污染状 况。 4. 四角蛤蜊软体部重金属含量进行风险评价,首先,利用单因子污染指数法比较分析, 发现从1997 年-2008 年,渤海湾四角蛤蜊软体部Cd 的污染水平在不断降低,现在其含量 已低于《海洋生物质量标准》(第二类)标准。而Cr、As 有污染的趋势,需要引起重视。 然后,利用金属污染指数法进行比较研究,发现B 断面>A 断面>C 断面。最后,利用《人 体消费卫生标准》进行比较分析,发现Cd、Ni 存在轻度污染,因此需要加强其污染源的 控制。 5. 渤海湾污染物除了重金属外,还存在一些典型持久性有机污染物。为进一步揭示 二者间协同毒理机制,利用分子系统学方法,对芳香烃受体通道进行了探索性研究,发现 水生动物AhR通道基因在进化过程中发生了适应性进化,对进一步研究重金属和POPs对双 壳贝类的毒理机制具有参考价值。
Resumo:
Long term, high quality estimates of burned area are needed for improving both prognostic and diagnostic fire emissions models and for assessing feedbacks between fire and the climate system. We developed global, monthly burned area estimates aggregated to 0.5° spatial resolution for the time period July 1996 through mid-2009 using four satellite data sets. From 2001ĝ€ "2009, our primary data source was 500-m burned area maps produced using Moderate Resolution Imaging Spectroradiometer (MODIS) surface reflectance imagery; more than 90% of the global area burned during this time period was mapped in this fashion. During times when the 500-m MODIS data were not available, we used a combination of local regression and regional regression trees developed over periods when burned area and Terra MODIS active fire data were available to indirectly estimate burned area. Cross-calibration with fire observations from the Tropical Rainfall Measuring Mission (TRMM) Visible and Infrared Scanner (VIRS) and the Along-Track Scanning Radiometer (ATSR) allowed the data set to be extended prior to the MODIS era. With our data set we estimated that the global annual area burned for the years 1997ĝ€ "2008 varied between 330 and 431 Mha, with the maximum occurring in 1998. We compared our data set to the recent GFED2, L3JRC, GLOBCARBON, and MODIS MCD45A1 global burned area products and found substantial differences in many regions. Lastly, we assessed the interannual variability and long-term trends in global burned area over the past 13 years. This burned area time series serves as the basis for the third version of the Global Fire Emissions Database (GFED3) estimates of trace gas and aerosol emissions.
Resumo:
Thèse diffusée initialement dans le cadre d'un projet pilote des Presses de l'Université de Montréal/Centre d'édition numérique UdeM (1997-2008) avec l'autorisation de l'auteur.
Resumo:
Thèse diffusée initialement dans le cadre d'un projet pilote des Presses de l'Université de Montréal/Centre d'édition numérique UdeM (1997-2008) avec l'autorisation de l'auteur.
Resumo:
Thèse diffusée initialement dans le cadre d'un projet pilote des Presses de l'Université de Montréal/Centre d'édition numérique UdeM (1997-2008) avec l'autorisation de l'auteur.
Resumo:
Thèse diffusée initialement dans le cadre d'un projet pilote des Presses de l'Université de Montréal/Centre d'édition numérique UdeM (1997-2008) avec l'autorisation de l'auteur.
Resumo:
Thèse diffusée initialement dans le cadre d'un projet pilote des Presses de l'Université de Montréal/Centre d'édition numérique UdeM (1997-2008) avec l'autorisation de l'auteur.
Resumo:
Thèse diffusée initialement dans le cadre d'un projet pilote des Presses de l'Université de Montréal/Centre d'édition numérique UdeM (1997-2008) avec l'autorisation de l'auteur.
Resumo:
Thèse diffusée initialement dans le cadre d'un projet pilote des Presses de l'Université de Montréal/Centre d'édition numérique UdeM (1997-2008) avec l'autorisation de l'auteur.
Resumo:
Thèse diffusée initialement dans le cadre d'un projet pilote des Presses de l'Université de Montréal/Centre d'édition numérique UdeM (1997-2008) avec l'autorisation de l'auteur.
Resumo:
Thèse diffusée initialement dans le cadre d'un projet pilote des Presses de l'Université de Montréal/Centre d'édition numérique UdeM (1997-2008) avec l'autorisation de l'auteur.
Resumo:
Thèse diffusée initialement dans le cadre d'un projet pilote des Presses de l'Université de Montréal/Centre d'édition numérique UdeM (1997-2008) avec l'autorisation de l'auteur.
Resumo:
Thèse diffusée initialement dans le cadre d'un projet pilote des Presses de l'Université de Montréal/Centre d'édition numérique UdeM (1997-2008) avec l'autorisation de l'auteur.