2,823 research outputs found
A biomimetic algorithm for the improved detection of microarray features,
One the major difficulties of microarray technology relate to the processing of large and - importantly - error-loaded images of the dots on the chip surface. Whatever the source of these errors, those obtained in the first stage of data acquisition - segmentation - are passed down to the subsequent processes, with deleterious results. As it has been demonstrated recently that biological systems have evolved algorithms that are mathematically efficient, this contribution attempts to test an algorithm that mimics a bacterial-"patented" algorithm for the search of available space and nutrients to find, "zero-in" and eventually delimitate the features existent on the microarray surface
Evolutionary Behavior Tree Approaches for Navigating Platform Games
Computer games are highly dynamic environments, where players are faced with a multitude of potentially unseen scenarios. In this article, AI controllers are applied to the Mario AI Benchmark platform, by using the Grammatical Evolution system to evolve Behavior Tree structures. These controllers are either evolved to both deal with navigation and reactiveness to elements of the game, or used in conjunction with a dynamic A* approach. The results obtained highlight the applicability of Behavior Trees as representations for evolutionary computation, and their flexibility for incorporation of diverse algorithms to deal with specific aspects of bot control in game environments
The effect of bovine milk lactoferrin on human breast cancer cell lines
The evidence that biologically active food components are key environmental factors
affecting the incidence of many chronic diseases is overwhelming. However, the full
extent of such components in our diet is unknown, as well as our understanding of their mechanisms of action. Beyond their interaction with the gut and intestinal immune
functions, more benefits are being tested for whey proteins such as lactoferrin, namely
as anti-cancer agents. Lactoferrin is an iron-binding protein that has been reported to
inhibit several types of cancer. In the present work, the effects of bovine milk lactoferrin
on human breast cancer HS578T and T47D cells were studied. The cells were either
untreated or submitted to lactoferrin concentrations ranging from 0. 125 to 125 μM.
Lactoferrin decreased 47% and 54% the cell viability of HS578T and T47D,
respectively, and increased apoptosis about twofold for both cell lines. Proliferation
rates decreased between 40.3 and 63.9% for HS578T and T47D, respectively. T47D cell
migration decreased in the presence of the protein. Although the mechanisms of action
have still not been unrevealed, the results gathered in this work suggest that lactoferrin
interferes with some of the most important steps involved in cancer development.(undefined
Verificação, avaliação e processamento das informações do programa de melhoramento de trigo para acesso e consulta por meio de bancos de dados relacional e grafo.
Editores técnicos: Joseani Mesquita Antunes, Ana Lídia Variani Bonato, Márcia Barrocas Moreira Pimentel
Parallel Mapper
The construction of Mapper has emerged in the last decade as a powerful and
effective topological data analysis tool that approximates and generalizes
other topological summaries, such as the Reeb graph, the contour tree, split,
and joint trees. In this paper, we study the parallel analysis of the
construction of Mapper. We give a provably correct parallel algorithm to
execute Mapper on multiple processors and discuss the performance results that
compare our approach to a reference sequential Mapper implementation. We report
the performance experiments that demonstrate the efficiency of our method
Conformational spread as a mechanism for cooperativity in the bacterial flagellar switch
The bacterial flagellar switch that controls the direction of flagellar rotation during chemotaxis has a highly cooperative response. This has previously been understood in terms of the classic two-state, concerted model of allosteric regulation. Here, we used high-resolution optical microscopy to observe switching of single motors and uncover the stochastic multistate nature of the switch. Our observations are in detailed quantitative agreement with a recent general model of allosteric cooperativity that exhibits conformational spread—the stochastic growth and shrinkage of domains of adjacent subunits sharing a particular conformational state. We expect that conformational spread will be important in explaining cooperativity in other large signaling complexes
Ecological research in the Large Scale Biosphere Atmosphere Experiment in Amazonia: A discussion of early results
The Large-scale Biosphere–Atmosphere Experiment in Amazonia (LBA) is a multinational, interdisciplinary research program led by Brazil. Ecological studies in LBA focus on how tropical forest conversion, regrowth, and selective logging influence carbon storage, nutrient dynamics, trace gas fluxes, and the prospect for sustainable land use in the Amazon region. Early results from ecological studies within LBA emphasize the variability within the vast Amazon region and the profound effects that land-use and land-cover changes are having on that landscape. The predominant land cover of the Amazon region is evergreen forest; nonetheless, LBA studies have observed strong seasonal patterns in gross primary production, ecosystem respiration, and net ecosystem exchange, as well as phenology and tree growth. The seasonal patterns vary spatially and interannually and evidence suggests that these patterns are driven not only by variations in weather but also by innate biological rhythms of the forest species. Rapid rates of deforestation have marked the forests of the Amazon region over the past three decades. Evidence from ground-based surveys and remote sensing show that substantial areas of forest are being degraded by logging activities and through the collapse of forest edges. Because forest edges and logged forests are susceptible to fire, positive feedback cycles of forest degradation may be initiated by land-use-change events. LBA studies indicate that cleared lands in the Amazon, once released from cultivation or pasture usage, regenerate biomass rapidly. However, the pace of biomass accumulation is dependent upon past land use and the depletion of nutrients by unsustainable land-management practices. The challenge for ongoing research within LBA is to integrate the recognition of diverse patterns and processes into general models for prediction of regional ecosystem function
- …
