718 research outputs found
Using Self-Adaptive Evolutionary Algorithms to Evolve Dynamism-Oriented Maps for a Real Time Strategy Game
9th International Conference on Large Scale Scientific Computations. The final publication is available at link.springer.comThis work presents a procedural content generation system that uses an evolutionary algorithm in order to generate interesting maps for a real-time strategy game, called Planet Wars. Interestingness is here captured by the dynamism of games (i.e., the extent to which they are action-packed). We consider two different approaches to measure the dynamism of the games resulting from these generated maps, one based on fluctuations in the resources controlled by either player and another one based on their confrontations. Both approaches rely on conducting several games on the map under scrutiny using top artificial intelligence (AI) bots for the game. Statistic gathered during these games are then transferred to a fuzzy system that determines the map's level of dynamism. We use an evolutionary algorithm featuring self-adaptation of mutation parameters and variable-length chromosomes (which means maps of different sizes) to produce increasingly dynamic maps.TIN2011-28627-C04-01, P10-TIC-608
Virtual player design using self-learning via competitive coevolutionary algorithms
The Google Artificial Intelligence (AI) Challenge
is an international contest the objective of which is to program the AI in a two-player real time strategy (RTS) game. This AI is an autonomous computer program that governs the actions that one of the two players executes during the game according to the state of play. The entries
are evaluated via a competition mechanism consisting of two-player rounds where each entry is tested against others.
This paper describes the use of competitive coevolutionary (CC) algorithms for the automatic generation of winning game strategies in Planet Wars, the RTS game associated with the 2010 contest. Three different versions of a prime
algorithm have been tested. Their common nexus is not only the use of a Hall-of-Fame (HoF) to keep note of the winners of past coevolutions but also the employment of an archive of experienced players, termed the hall-of-celebrities
(HoC), that puts pressure on the optimization process and guides the search to increase the strength of the solutions; their differences come from the periodical updating of the HoF on the basis of quality and diversity metrics.
The goal is to optimize the AI by means of a self-learning process guided by coevolutionary search and competitive evaluation. An empirical study on the performance of a number of variants of the proposed algorithms is described and a statistical analysis of the results is conducted. In addition to the attainment of competitive bots we also
conclude that the incorporation of the HoC inside the primary algorithm helps to reduce the effects of cycling caused by the use of HoF in CC algorithms.This work is partially supported by Spanish
MICINN under Project ANYSELF (TIN2011-28627-C04-01),3 by Junta de Andalucía under Project P10-TIC-6083 (DNEMESIS) and by Universidad de Málaga, Campus de Excelencia Internacional Andalucía Tech
Endogenous production of ghrelin and beneficial effects of its exogenous administration in monocrotaline-induced pulmonary hypertension
We investigated the endogenous production of ghrelin as well as cardiac and pulmonary vascular effects of its administration in a rat model of monocrotaline (MCT)-induced pulmonary hypertension (PH). Adult Wistar rats randomly received a subcutaneous injection of MCT (60 mg/kg) or an equal volume of vehicle. One week later, animals were randomly assigned to receive a subcutaneous injection of ghrelin (100 mug/kg bid for 2 wk) or saline. Four groups were analyzed: normal rats treated with ghrelin (n = 7), normal rats injected with saline (n = 7), MCT rats treated with ghrelin (n = 9), and MCT rats injected with saline (n = 9). At 22-25 days, right ( RV) and left ventricular (LV) pressures were measured, heart and lungs were weighted, and samples were collected for histological and molecular analysis. Endogenous production of ghrelin was almost abolished in normal rats treated with ghrelin. In MCT-treated animals, pulmonary expression of ghrelin was preserved, and RV myocardial expression was increased more than 20 times. In these animals, exogenous administration of ghrelin attenuated PH, RV hypertrophy, wall thickening of peripheral pulmonary arteries, and RV diastolic disturbances and ameliorated LV dysfunction, without affecting its endogenous production. In conclusion, decreased tissular expression of ghrelin in healthy animals but not in PH animals suggests a negative feedback in the former that is lost in the latter. A selective increase of ghrelin mRNA levels in the RV of animals with PH might indicate distinct regulation of its cardiac expression. Finally, ghrelin administration attenuated MCT-induced PH, pulmonary vascular remodeling, and RV hypertrophy, indicating that it may modulate PH
Detecting natural disasters, damage, and incidents in the wild
Responding to natural disasters, such as earthquakes, floods, and wildfires,
is a laborious task performed by on-the-ground emergency responders and
analysts. Social media has emerged as a low-latency data source to quickly
understand disaster situations. While most studies on social media are limited
to text, images offer more information for understanding disaster and incident
scenes. However, no large-scale image datasets for incident detection exists.
In this work, we present the Incidents Dataset, which contains 446,684 images
annotated by humans that cover 43 incidents across a variety of scenes. We
employ a baseline classification model that mitigates false-positive errors and
we perform image filtering experiments on millions of social media images from
Flickr and Twitter. Through these experiments, we show how the Incidents
Dataset can be used to detect images with incidents in the wild. Code, data,
and models are available online at http://incidentsdataset.csail.mit.edu.Comment: ECCV 202
Ghrelin reverses molecular, structural and hemodynamic alterations of the right ventricle in pulmonary hypertension
Ghrelin is an endogenous peptide that has a dual effect by activating specific receptors and by stimulating release of growth hormone. There is increasing evidence that ghrelin has a potent vasodilator effect. Recently, we demonstrated that exogenous administration of ghrelin modulates its endogenous levels and attenuates the majority of alterations induced by monocrotaline (MCT). In the present study, we evaluate the effects of chronic administration of ghrelin on hemodynamic and morphometric parameters of the right ventricle, as well as on myocardial levels of SERCA2a and endothelin-1. Adult Wistar rats were injected with MCT (60 mg/kg, sc) or just the vehicle (day 0). One week later, the animals treated with MCT were randomly divided into two groups and treated with ghrelin (100 microg/kg, bid, sc) or with a similar volume of vehicle. Between days 21-25 the animals were instrumented to record right ventricular (RV) pressures and samples were collected for morphological and molecular analysis. Ghrelin treatment attenuated the effects of MCT, namely: RV myocyte fiber diameter, pulmonary vascular remodeling (evaluated by % medial wall thickness of peripheral arteries), RV peak systolic pressure, RV end-diastolic pressure, time constant tau, and SERCA2a and endothelin-1 mRNA levels. Chronic ghrelin administration attenuates MCT-induced pulmonary hypertension, vascular remodeling and RV hypertrophy. These results suggest a potential therapeutic role for the ghrelin-growth hormone axis in pulmonary hypertension
Evaluation of the QuEChERS Method and Gas Chromatography–Mass Spectrometry for the Analysis Pesticide Residues in Water and Sediment
A method for the determination of pesticide residues in water and sediment was developed using the QuEChERS method followed by gas chromatography – mass spectrometry. The method was validated in terms of accuracy, specificity, linearity, detection and quantification limits. The recovery percentages obtained for the pesticides in water at different concentrations ranged from 63 to 116%, with relative standard deviations below 12%. The corresponding results from the sediment ranged from 48 to 115% with relative standard deviations below 16%. The limits of detection for the pesticides in water and sediment were below 0.003 mg L−1 and 0.02 mg kg−1, respectively
What traits are carried on mobile genetic elements, and why?
Although similar to any other organism, prokaryotes can transfer genes vertically from mother cell to daughter cell, they can also exchange certain genes horizontally. Genes can move within and between genomes at fast rates because of mobile genetic elements (MGEs). Although mobile elements are fundamentally self-interested entities, and thus replicate for their own gain, they frequently carry genes beneficial for their hosts and/or the neighbours of their hosts. Many genes that are carried by mobile elements code for traits that are expressed outside of the cell. Such traits are involved in bacterial sociality, such as the production of public goods, which benefit a cell's neighbours, or the production of bacteriocins, which harm a cell's neighbours. In this study we review the patterns that are emerging in the types of genes carried by mobile elements, and discuss the evolutionary and ecological conditions under which mobile elements evolve to carry their peculiar mix of parasitic, beneficial and cooperative genes
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