18 research outputs found
Efeitos gĂȘnicos de caracteres associados Ă eficiĂȘncia no uso de nitrogĂȘnio em milho
DES science portal: Computing photometric redshifts
A significant challenge facing photometric surveys for cosmological purposes is the need to produce reliable redshift estimates. The estimation of photometric redshifts (photo-zs) has been consolidated as the standard strategy to bypass the high production costs and incompleteness of spectroscopic redshift samples. Training-based photo-z methods require the preparation of a high-quality list of spectroscopic redshifts, which needs to be constantly updated. The photo-z training, validation, and estimation must be performed in a consistent and reproducible way in order to accomplish the scientific requirements. To meet this purpose, we developed an integrated web-based data interface that not only provides the framework to carry out the above steps in a systematic way, enabling the ease testing and comparison of different algorithms, but also addresses the processing requirements by parallelizing the calculation in a transparent way for the user. This framework called the Science Portal (hereafter Portal) was developed in the context the Dark Energy Survey (DES) to facilitate scientific analysis. In this paper, we show how the Portal can provide a reliable environment to access vast datasets, provide validation algorithms and metrics, even in the case of multiple photo-zs methods. It is possible to maintain the provenance between the steps of a chain of workflows while ensuring reproducibility of the results. We illustrate how the Portal can be used to provide photo-z estimates using the DES first year (Y1A1) data. While the DES collaboration is still developing techniques to obtain more precise photo-zs, having a structured framework like the one presented here is critical for the systematic vetting of DES algorithmic improvements and the consistent production of photo-zs in future DES releases
NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics
Xenarthrans â anteaters, sloths, and armadillos â have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with 24 domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, ten anteaters, and six sloths. Our dataset includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data-paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the south of the USA, Mexico, and Caribbean countries at the northern portion of the Neotropics, to its austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n=5,941), and Cyclopes sp. has the fewest (n=240). The armadillo species with the most data is Dasypus novemcinctus (n=11,588), and the least recorded for Calyptophractus retusus (n=33). With regards to sloth species, Bradypus variegatus has the most records (n=962), and Bradypus pygmaeus has the fewest (n=12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other datasets of Neotropical Series which will become available very soon (i.e. Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans dataset
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%â18% 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
Developing a management decision-making model based upon a complexity perspective with reference to the Bee Algorithm
Today's business world is characterized by a complex non-linear environment, non-hierarchical organization structures, multi-country and de-centralized operations, etc. The prominent models of decision-making that were primarily developed with the industrial economy in mind, and that viewed decision-making as a couple of linear sequential steps and "decisions given-and-decisions followed" - might not work too well. Knowledge-based economies call for developing decision-making models that represent the complexity of the present world business. Under such context, we present an alternative approach to studying management decision-making - seeking inspiration from the natural/biological systems. Bees show similar behavior in their foraging activities, as a single objective management decision-making problem. The uniqueness of the developed model lies in its ability to explain the major properties of a complex system, and the value that emergence (of a decision) brings to a company
Thermodynamic analysis and reaction routes of steam reforming of bio-oil aqueous fraction
Anålise da sustentabilidade da geração de eletricidade do Cearå
A matriz elĂ©trica cearense distingue-se da matriz elĂ©trica brasileira por ser alicerçada, principalmente, em usinas eĂłlicas e tĂ©rmicas que fornecem, juntas, 99% da produção de eletricidade do estado. Em relação Ă demanda por eletricidade do CearĂĄ, do ano de 1981 atĂ© 2015, houve um crescimento de cerca de 747%, com um crescimento mĂ©dio de 21,34% ao ano. O presente artigo tem como objetivo analisar o comportamento de Ăndices de sustentabilidade para o setor de geração de energia elĂ©trica cearense. Para isso, os seguintes multicritĂ©rios de anĂĄlise da sustentabilidade na matriz elĂ©trica sĂŁo considerados: emissĂŁo de gases de efeito estufa; ĂĄrea imobilizada; uso de recursos de combustĂvel; uso de ĂĄgua; morbidade; confiabilidade da geração e eficiĂȘncia energĂ©tica. A proposta desenvolvida divide os pesos dos multicritĂ©rios no aspecto social e tĂ©cnico (40%) e nos parĂąmetros ambientais (60%). No CearĂĄ, dentro dos parĂąmetros ambientais, o Ăndice referente ao consumo de ĂĄgua, devido Ă inconstĂąncia de chuvas, recebeu a maior ponderação de impactos na sustentabilidade (30%)