1,242 research outputs found
Soil microbial biomass in organic farming system.
Agricultural production systems have to combine management practices in order to sustain soil's profitability and quality. Organic farming is gaining worldwide acceptance and has been expanding at an annual rate of 20% in the last decade, accounting for over 24 million hectares worldwide. Organic practices avoid applications of synthetic fertilizers and pesticides, rely on organic inputs and recycling for nutrient supply, and emphasize cropping system design and biological processes for pest management, as defined by organic farming regulation in the world. In comparison with conventional farming, organic farming has potential benefits in improving food quality and safety. Plant production in organic farming mainly depends on nutrient release as a function of mineralization processes in soils. The build-up of a large and active soil microbial biomass is important pool of accessible nutrients, therefore, is an important priority in organic farming. In organic farming, there is positive effect of quantity and quality of inputs of organic residues on soil microbial biomass. In this way, the organic systems are extremely important for the increase of the soil fertility and the maintenance of the environmental sustainability
contemporary struggles for land in Brazil and Colombia
The struggles for land discussed in this paper have occurred in contexts
characterized by some improvement of laws and policies designed to protect
ethnic and cultural minorities in Brazil and Colombia, following the
“multicultural turn” in international law. The paper discusses to a greater
extent the cases of communities of Afro-descendants who live in areas disputed
by agribusiness companies interested in expanding palm plantations mostly for
biodiesel production. We found out that the introduction of new rights has
first unleashed a local process of ethnic re-identification. In a certain way,
minority rights themselves have created those minorities they are supposed to
protect. Nevertheless, new minority rights have also reframed the conditions
under which struggles for land are conducted and negotiated in Colombia as
well as in Brazil. Seen as relays in an electrical circuit, minority rights
serve to modulate power at the local level: in some cases, new rights amplify
minorities’ power; in other situations, they can help contain the problems of
abuses of power
Ruiniform relief in sandstones: the examples of Vila Velha, Carboniferous of the Paraná Basin, Southern Brazil
Profile of practice, travel behaviour and motivations for geocaching
Geocaching is a recreational sport activity considered as apostmodern treasure hunting game. Associated with the movement to distant places, the search for new landscapes, culture and adventure, geocaching is being integrated into the tourism industry. In spite of its growth and economic significance, few studieshave been developed to understand this sport tourism activity. Thus, this study was developed to understand the geocaching practice profile, geocaching travel behaviour and the motivations for the practice of geocaching, and to examine whether these variables are associated with the socio-demographic characteristics of geocachers.An online questionnaire survey was applied to geocachers living in Portugal, and 613 responses were obtained. The results show that geocaching is a recent sport activity in Portugal, whose motivations for practice are related to nature and escape, and that geocachers have a strong disposition to travel, highlighting the potential of geocaching for sport tourism. Statistical tests also revealed that socio-demographic characteristics are not associated with the geocaching practice profile and geocaching travel behaviour. However, the socio-demographic characteristics are associated with the motivations for the practice of geocaching, particularly when compared by sex, age and education level. Management and marketing implications for sport tourism operators and destinations are discussed.info:eu-repo/semantics/publishedVersio
Susceptibility assessment of shallow slides failure and run-out
The research is focused on the susceptibility assessment of shallow slides in the region north of Lisbon (Portugal), by modelling the failure and run-out areas separately. The shallow slides failure is evaluated using a statistical method (logistic regression). The existence of shallow slides inventories occurred in distinct periods allowed the separation of data into two independent groups (training and validation) and the adoption of the temporal criterion for the independent validation. The latter revealed an Area Under the Receiver Operating Characteristic curve of 0.90, which reflects a very good predictive capacity of the logistic regression model.
For the run-out assessment, a simple cellular automata model is implemented through the following sequential steps: a) pre-processing and establishment of transition rules; b) integration of variables; and c) temporal indexing and simulation. The pre-processing step includes the creation of a database with the modelling inputs. The transition rules are directly related with the motion of the displaced mass. In this context, the likely traveling directions are identified, both horizontally and vertically. The integration of transition rules is performed using the algorithm Path Distance, from ESRI. For the temporal indexing, we use the Markov chains analysis to estimate a transition area matrix, which records the number of cells that is expected to change location over a specified time. The last stage refers to the cellular automata model simulation, i.e. to the spatial distribution of the landslide displaced mass. The run-out modelling, using the cellular automata model proposed, provided good results, with an overlap between the simulation and the real cases of 77%. Lastly, a final shallow slide susceptibility map was constructed including both failure and run-out areas. This work accomplished a combination of low-cost methodology with limited input data that allowed a good performance of the landslide susceptibility assessment and can be easily applied to other regions.info:eu-repo/semantics/publishedVersio
Combination of statistical and physically based methods to assess shallow slide susceptibility at the basin scale
Approaches used to assess shallow slide susceptibility at the basin scale are conceptually different depending on the use of statistical or physically based methods. The former are based on the assumption that the same causes are more likely to produce the same effects, whereas the latter are based on the comparison between forces which tend to promote movement along the slope and the counteracting forces that are resistant to motion. Within this general framework, this work tests two hypotheses: (i) although conceptually and methodologically distinct, the statistical and deterministic methods generate similar shallow slide susceptibility results regarding the model's predictive capacity and spatial agreement; and (ii) the combination of shallow slide susceptibility maps obtained with statistical and physically based methods, for the same study area, generate a more reliable susceptibility model for shallow slide occurrence. These hypotheses were tested at a small test site (13.9 km2) located north of Lisbon (Portugal), using a statistical method (the information value method, IV) and a physically based method (the infinite slope method, IS). The landslide susceptibility maps produced with the statistical and deterministic methods were combined into a new landslide susceptibility map. The latter was based on a set of integration rules defined by the cross tabulation of the susceptibility classes of both maps and analysis of the corresponding contingency tables. The results demonstrate a higher predictive capacity of the new shallow slide susceptibility map, which combines the independent results obtained with statistical and physically based models. Moreover, the combination of the two models allowed the identification of areas where the results of the information value and the infinite slope methods are contradictory. Thus, these areas were classified as uncertain and deserve additional investigation at a more detailed scale.info:eu-repo/semantics/publishedVersio
Does the Updating of Landslides Inventories Have a Relevant Impact on the Landslide Susceptibility Assessment?
Landslide inventories are essential for developing an
accurate susceptibility assessment. However, the complete and systematic updating of these inventories is a
time-consuming and challenging task. Therefore, we
aimed to verify if the temporal updating of historical
inventories improves the susceptibility models and if the
size of the study area plays a relevant role in the decision
to update or not landslide inventories. To answer these
questions, the work was carried out in two study areas
with different sizes but with a similar geomorphological
context. The landslide susceptibility modelling, developed using the Information Value method, was performed
for distinct types of landslides and using three landslide
inventories: one with landslides that occurred before
2012; a second with landslides that occurred during the
event of 2010; and a third with landslides that occurred up
to 2019. The results indicate no improvement or only a
residual enhancement in the susceptibility models’ predictive capacity, regardless of the type of landslide or the
study area’s size.info:eu-repo/semantics/publishedVersio
PRÁTICAS DE MONTAGEM NA ESCOLA DE TEATRO DA UFBA: ensaio a partir de lembranças de um professor entre 2011 e 2013
O presente ensaio busca reunir breves relatos de processos de ensino e de aprendizagem deste professor na Escola de Teatro da Universidade Federal da Bahia (ETUFBA) entre os anos de 2011 e 2013. Para tanto, foram selecionadas três práticas de montagem e reflexões a partir das respectivas experiências relacionais. O relato contribui com estudos relativos à história da formação artística no campo das artes da cena, particularmente na Escola de Teatro fundada em 1956, em Salvador, a alma mater dos cursos universitários de teatro no Brasil. PALAVRAS-CHAVE: ETUFBA. Interpretação. Relacionalidade. História da educação teatral
Draining beds: natural system for sludge volume reduction in the water treatment plant
As Estações de Tratamento de Água (ETAs) tem funcionamento semelhante a uma indústria e podem em diversas etapas gerar resíduos que, na maioria das ETAs, são lançados nos corpos d’água sem tratamento. Neste trabalho avaliou-se o desempenho de Leitos de Drenagem, para o desaguamento de lodo, provenientes de ETAs de ciclo completo que empregam sulfato de alumínio e cloreto de polialumínio (PACl), como coagulantes. Analisou-se as características, a drenagem e secagem dos amostras de lodo e característica do drenado. Os Leitos de Drenagem mostraram-se eficientes para desaguamento e redução de volume de lodo de ETA, de forma natural, sem consumo de energia ou adição de produtos químicos. Obteve-se, aos sete dias, reduções da ordem de 87 % em volume para os lodos de PACl e 83 % para o lodo de Sulfato de Alumínio e teor de sólidos totais 28% e 31% respectivamente.In this work the performance of Draining Beds for sludge dewatering was assessed. The sludge was provided from full cycle Water Treatment Plants (WTPs) that employ aluminum sulfate and polyaluminium chloride (PACl) as coagulants. The characteristics, drainage and drying of samples of sludge and characteristic of drained were analysed. The Draining Beds were shown to be efficient for dewatering and sludge volume reduction in the WTP, in a natural way, without energy consumption or adding of chemical products. On the seventh day, it was possible to obtain reduction around 87% in volume for PACl sludge and 83% for the aluminum sulfate sludge and total solids content of 28 and 31% respectively
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