3,692 research outputs found
Strawberry tree biophysical units’ ecology to design provenance regions in Portugal using GIS tools
Strawberry tree (Arbutus unedo L.) displays potential to be successfully businesslike cultured in several regions of Portugal and southern Europe, where it is well adapted to climate and soils. In Portugal, this species has been used by local populations for fruit consumption and spirit production, but remains largely a neglected crop. It has different possible commercial uses, since processed and fresh fruit production to ornamental, pharmaceutical and chemical applications, due to the phenolic acids and terpenoid compounds with strong antioxidant activity, vitamin C and tannin content. In addition, due to its pioneer status, it is valuable for land recovery and desertification avoidance, besides being fire resistant. Currently, the demand for improved plants has strongly increased. Under the project ARBUTUS (PTDC/AGR-FOR/3746/2012, Arbutus unedo plants and products quality improvement for the agro-forestry sector) 30 trees were selected, in 15 natural populations distributed throughout the country. The stands were ecologically characterized locally, using bioclimatology, lithology, topography, soil type, vegetation and wildfires records, as biophysical units. The data processed was the digital elevation model (DEM), the soil maps, the annual burnt areas since 1975, and the phytosociological and biogeographical maps. In parallel, the climatological data were collected (1981-2010) from various weather stations and bioclimatological indices maps, constructed by Monteiro-Henriques (2010), in order to calculate bioclimatic indices, using geostatistical tools. An exploratory multivariate statistical approach was performed with the collected information: principal component analysis (PCA) and hierarchical cluster analysis (HCA). The obtained information will be used for the provenance regions design in order to select plus trees and for tree species genetic improvement purposes, besides forest tree conservation programs design
Tracking sound source localization for a home robot application
The future of robotics is now trending for home servicing. Nursing homes and assistance to elder peopleare areas where robots can provide valuable help in order to improve the quality of life of those who need it most. Calling a robot,for a person of age,can be a daunting task if the voice is failing and any resort to battery operated devices failsto comply. Using a simple mechanical apparatus,such as aClick trainerfordogs, a person can call a robot by pressing thebutton of a powerless device. The high pitch sound produced by this device can be captured and tracked down in order to estimate the person’s location within a room. This paper describes a method that provides good accuracy and uses simple and low cost technology,in order to provide an efficient positional value for an assistance robot to attend its caller. The robot does not need to search for the person in aroom as it can directly travel towards the Click’s sound source.info:eu-repo/semantics/publishedVersio
Utilização da análise espacial multicritério para avaliação da aptidão biogeofísica do medronheiro na região Centro
O medronheiro (Arbutus unedo L.) é uma espécie autóctone em Portugal, com distribuição ubíqua, tolerante à secura estival, a solos de baixa fertilidade e com uma resistência ativa a incêndios florestais. Neste estudo pretendeu-se identificar o habitat mais favorável para a espécie na região Centro com base na integração de um conjunto de fatores biogeofísicos. Foram, para esse efeito estimados descritores baseados no relevo, no solo, no histórico de incêndios, no coberto vegetal atual e potencial, tendo como base o modelo digital do terreno, a cartografia de solos, os perímetros de áreas ardidas e a cartografia fitossociológica e biogeográfica. Foram recolhidos dados climatológicos a partir de várias estações meteorológicas e mapas bioclimatológicos para calcular os índices bioclimáticos, usando ferramentas geoestatísticas. Os diferentes temas foram classificados em três níveis de aptidão para a espécie: desfavorável, pouco favorável e favorável. Com base nos temas resultantes da reclassificação em níveis de aptidão, calculou-se o índice de adequabilidade de habitat (HSI) para o medronheiro. Esta avaliação da aptidão para o medronheiro foi efetuada com recurso ao método de análise espacial multicritério (AHP). Segundo o AHP, os pesos e prioridades a atribuir aos critérios resultam de um conjunto de julgamentos subjetivos realizados por participantes envolvidos no processo, sendo desenvolvidas matrizes de comparação par a par, utilizando uma escala de nove níveis
Fast computational processing for mobile robots' self-localization
This paper intends to present a different approach
to solve the Self-Localization problem regarding a RoboCup’s
Middle Size League game, developed by MINHO team
researchers. The method uses white field markings as key points,
to compute the position with least error, creating an error-based
graphic where the minimum corresponds to the real position,
that are computed by comparing the key (line) points with a
precomputed set of values for each position. This approach
allows a very fast local and global localization calculation,
allowing the global localization to be used more often, while
driving the estimate to its real value. Differently from the
majority of other teams in this league, it was important to come
up with a new and improved method to solve the traditional slow
Self-Localization problem.This work was developed at the Laboratório de Automação e Robótica by MINHO team´s researching and developing team, at University of Minho, under the supervision of Professor A. Fernando Ribeiro and A. Gil Lopes. The knowledge exchanging between the RoboCup’s MSL teams and community contributed greatly for the development of this work. This work has been supported by COMPETE: POCI-01- 0145-FEDER-007043 and FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2013.info:eu-repo/semantics/publishedVersio
Motion control of mobile autonomous robots using non-linear dynamical systems approach
This paper presents a solution to the problem of motion control of an
autonomous robot, moving in a dynamical and unstable environment. It is based
on non-linear dynamical systems, modelling the state variables that define the
motion of a robot under an omnidirectional platform, like its direction of navigation
and velocity. The approach used, is based on a set of non-linear differential
equations that model the evolution of state variables along time, based on
the concept of attractors and repellers. In the official RoboCup Middle Size
League field, a target is used to attract the robot to a certain position (could be
the ball or a desired position to receive the ball), while a repeller could move
the robot away from its original path (given by obstacles in the surrounding environment).
The research was firstly carried out in a computational simulation
environment and later on with robots in a real environmentThis work was developed at the Automation and Robotics Laboratory by MINHO R&D TEAM, University of Minho, under the supervision of Professor A. Fernando Ribeiro and A. Gil Lopes. The knowledge exchanging between the RoboCup’s MSL teams and community contributed greatly for the development of this work. This work has been supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2013.info:eu-repo/semantics/publishedVersio
The cell wall and the response and tolerance to stresses of biotechnological relevance in yeasts
In industrial settings and processes, yeasts may face multiple adverse environmental conditions. These include exposure to non-optimal temperatures or pH, osmotic stress, and deleterious concentrations of diverse inhibitory compounds. These toxic chemicals may result from the desired accumulation of added-value bio-products, yeast metabolism, or be present or derive from the pre-treatment of feedstocks, as in lignocellulosic biomass hydrolysates. Adaptation and tolerance to industrially relevant stress factors involve highly complex and coordinated molecular mechanisms occurring in the yeast cell with repercussions on the performance and economy of bioprocesses, or on the microbiological stability and conservation of foods, beverages, and other goods. To sense, survive, and adapt to different stresses, yeasts rely on a network of signaling pathways to modulate the global transcriptional response and elicit coordinated changes in the cell. These pathways cooperate and tightly regulate the composition, organization and biophysical properties of the cell wall. The intricacy of the underlying regulatory networks reflects the major role of the cell wall as the first line of defense against a wide range of environmental stresses. However, the involvement of cell wall in the adaptation and tolerance of yeasts to multiple stresses of biotechnological relevance has not received the deserved attention. This article provides an overview of the molecular mechanisms involved in fine-tuning cell wall physicochemical properties during the stress response of Saccharomyces cerevisiae and their implication in stress tolerance. The available information for non-conventional yeast species is also included. These non-Saccharomyces species have recently been on the focus of very active research to better explore or control their biotechnological potential envisaging the transition to a sustainable circular bioeconomy
Clinical correlation between N-terminal pro-b-type natriuretic peptide and angiographic coronary atherosclerosis
OBJECTIVES: This study aimed to investigate the clinical correlation between angiographic coronary atherosclerosis and N-terminal pro-B-type natriuretic peptide along with other known correlated factors. METHODS: In total, 153 patients with a diagnostic hypothesis of stable angina, unstable angina or acute myocardial infarction were classified as group A (patients with angiographically normal coronary arteries) or group B (patients with angiographic coronary atherosclerosis). The two groups were analyzed with respect to the following factors: gender, age, body mass index, abdominal circumference, smoking, diabetes mellitus, arterial hypertension, early family history of atherosclerosis, statin use, the presence of metabolic syndrome, clinical presentation and biochemical factors, including cholesterol, creatinine and fibrinogen plasma concentrations, monocyte counts and N-terminal pro-B-type natriuretic peptide. RESULTS: Univariate analyses comparing the two groups revealed that group B patients more frequently had diabetes, used statins and had systolic dysfunction, N-terminal pro-B-type natriuretic peptide levels ≥250 pg/mL, fibrinogen levels >;500 mg/dL and ≥501 monocytes/mm3 compared with group A patients (
Autonomous 4DOF robotic manipulator prototype for industrial environment and human cooperation
This paper describes the design and development of an autonomous robotic manipulator with four degrees of freedom. The manipulator is named RACHIE - "Robotic Arm for Collaboration with Humans in Industrial Environment". The idea was to create a smaller version of the industrial manipulators available on the market. The mechanical and electronic components are presented as well as the software algorithms implemented on the robot. The manipulator has as its primary goal the detection and organization of cans by color and defects. The robot can detect a human operator so it can deliver defective cans by collaborating with him/her on an industrial environment. To be able to perform such task, the robot has implemented a machine learning algorithm, a Haar feature-based cascade classifier, on its vision system to detect cans and humans. On the handler motion, direct and inverse kinematics were calculated and implemented, and its equations are described in this paper. This robot presents high reliability and robustness in the task assigned. It is low-cost as it is a small version of commercial ones, making it optimized for smaller tasks
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