Algumas refle xões so bre a enge nharia civil e o am bie nte no co nte xto do século XX I

Diante do contexto de mudanças climáticas e demanda pelo aprimoramento na gestão de materiais, o objetivo desse trabalho é fazer uma análise da interação entre a construção civil e o meio ambiente. Constataram-se que por meio de modificações na indústria da construção civil é possível conseguir ganhos ambientais consideráveis em relação à redução da emissão de gases causadores do efeito estufa, contaminação da atmosfera, solo e fontes de água, e melhor uso de matérias primas. A sociedade de maneira geral tem se tornado mais exigente em relação a esses aspectos o que se reflete em atitudes da iniciativa privada como a busca por construções mais sustentáveis e por certificações das mesmas

Performance and amylase activity in Nile tilapia submitted to different temperatures

O objetivo deste trabalho foi avaliar o desempenho e a atividade de amilase em quimo de tilápias-do-nilo macho, linhagem tailandesa, submetidas a quatro diferentes temperaturas. O experimento foi conduzido em delineamento inteiramente casualizado, com quatro tratamentos (20, 24, 28 e 32oC), seis repetições e dez peixes por unidade experimental. A dieta utilizada foi igual para todos os tratamentos. Aos 55 dias do experimento, o consumo de ração aparente, ganho de peso, conversão alimentar aparente, atividade de amilase e atividade específica da amilase foram avaliados. O consumo de ração aparente e o ganho de peso aumentaram linearmente com o aumento da temperatura. Na conversão alimentar aparente, foi observado efeito quadrático em função da temperatura com melhora na conversão de 1,79 a 1,00 com o aumento da temperatura até 29,15oC. Observou-se efeito linear na atividade da amilase e na atividade específica da amilase em função da temperatura, com maior atividade de amilase e menor atividade específica de amilase a 32oC. A temperatura da água influencia o desempenho e a atividade da amilase em tilápias-do-nilo.The objective of this work was to evaluate the performance and amylase activity in chime of Nile tilapia male, Thai line, submitted to four different temperatures. The experimental design was completely randomized with four treatments (20, 24, 28 and 32oC), six replicates and ten fishes per experimental unit. The diet was the same for all treatments. At 55 days of experiment, apparent feed intake, weight gain, apparent feed conversion, amylase activity and specific amylase activity were evaluated. The apparent feed intake and weight gain increased linearly with temperature increase. For apparent feed conversion, quadratic effect was observed as a function of temperature, showing a conversion improvement of 1.79 to 1.00 with the increase of the temperature until 29,15oC. Linear effect in amylase activity and specific amylase activity was observed as a result of temperature, comprising high amylase activity and low specific amylase activity at 32oC. Water temperature influences the performance and amylase activity in Nile tilapia

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time, and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space. While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes, vast areas of the tropics remain understudied. In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity, but it remains among the least known forests in America and is often underrepresented in biodiversity databases. To worsen this situation, human-induced modifications may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge, it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Influencia de um sistema Silvipastoril estabelecido no bioma serrado sobre a ciclagem de nutrientes, atributos do solo, da forrageira e do armazenamento de carbono

Submitted by Anna Dias ([email protected]) on 2020-01-10T17:40:30Z No. of bitstreams: 1 Guilherme Lanna Reis.pdf: 1544758 bytes, checksum: daea8632a7e3a3725af90f76a04ff3d4 (MD5)Approved for entry into archive by Camila Silva ([email protected]) on 2020-01-15T21:23:15Z (GMT) No. of bitstreams: 1 Guilherme Lanna Reis.pdf: 1544758 bytes, checksum: daea8632a7e3a3725af90f76a04ff3d4 (MD5)Made available in DSpace on 2020-01-16T11:43:27Z (GMT). No. of bitstreams: 1 Guilherme Lanna Reis.pdf: 1544758 bytes, checksum: daea8632a7e3a3725af90f76a04ff3d4 (MD5) Previous issue date: 2007Políticas e tecnologias inadequadas contribuem consideravelmente para a insustentabilidade econômica, social e ambiental da produção agropecuária brasileira. O objetivo deste estudo foi avaliar o papel dos sistemas silvipastoris (SSP) na busca de pontos positivos que contribuam na sustentabilidade da pecuária brasileira. Analisou-se a influência de um SSP, estabelecido no bioma cerrado, por meio de regeneração natural da espécie arbórea nativa Ipê Felpudo (Zeyheria tuberculosa Vell. Bur), e Brachiaria brizantha cv. Marandu (BBM), na ciclagem dos nutrientes, nos atributos químicos e físicos do solo, na produtividade e no valor nutritivo da forrageira e no armazenamento de carbono. A espécie arbórea do sistema estudado, nesta densidade, influenciou a fertilidade do solo principalmente em relação à acidez, com o aumento do pH, cálcio (Ca+2), magnésio (Mg+2) e saturação por bases (V), e redução de alumínio trocável (Al+3), na camada superficial (0-2 cm). Em relação aos teores dos outros macronutrientes no solo, não houve influência das árvores provavelmente devido às altas relações carbono/nitrogênio (C/N) e lignina/N na liteira das árvores. Os atributos físicos foram ligeiramente afetados e ambos os sistemas foram eficientes na manutenção da estrutura física do solo. A presença do Ipê Felpudo em pastagens de BBM não reduziu a produção de matéria seca (MS) da BBM durante um período típico de veranico. Por outro lado, as árvores influenciaram a composição mineral da forrageira, Não houve alteração dos componentes fibrosos, entretanto, as arbóreas contribuíram para melhorar os aspectos nutricionais da forragem ao incrementar os níveis de proteína bruta. O SSP demonstrou o potencial de armazenar maior quantidade de carbono em relação ao controle (pasto sem árvores).Inadequate politics and technologies have contributed to the economic, social and environmental unsustainability of the agriculture and livestock production in Brazil. The aim of this study was to evaluate one silvopastoral systems (SPS) and also the positive effects which could be used for a sustainable animal production. The influence of a SPS on nutrient cycling, physical and chemical soil attributes, forage production and carbon sink was evaluated. The SPS was established in the Cerrado biome, through natural regeneration of the tree (Zeyheria tuberculosa Vell. Bur) and the grass forage (Brachiaria brizantha cv. Marandu) (BBM). The tree specie, at this density, increased the values of pH, calcium (Ca+2), magnesium (Mg+2) and bases saturation (V) reduced aluminum (Al+3) at 0-2 cm soil layer. The macronutrients concentration was not affected and could be influenced by the high relationship between carbon/nitrogen (C/N) and lignin/N on the trees litter. The physical attributes were slight influenced and both systems and were efficient at keeping the soil structure. The dry matter production of BBM were not affected by the presence of trees, during typical period of hydric stress. On the other hand, the mineral composition was influenced by the presence of trees. However, the crude protein concentration on BBM increased on the SSP. The SPS demonstrated the potential to increase carbon reservoir in relation to pastures cultivated as monoculture