6,268 research outputs found
Wind-CSP short-term coordination by MILP approach
This paper is on the maximization of total profit in a day-ahead market for a price-taker producer needing a short-term scheduling for wind power plants coordination with concentrated solar power plants, having thermal energy storage systems. The optimization approach proposed for the maximization of profit is a mixed-integer linear programming problem. The approach considers not only transmission grid constraints, but also technical operating constraints on both wind and concentrated solar power plants. Then, an improved short-term scheduling coordination is provided due to the more accurate modelling presented in this paper. Computer simulation results based on data for the Iberian wind and concentrated solar power plants illustrate the coordination benefits and show the effectiveness of the approach
Pragma-Oriented Parallelization of the Direct Sparse Odometry SLAM Algorithm
Monocular 3D reconstruction is a challenging computer
vision task that becomes even more stimulating when we
aim at real-time performance. One way to obtain 3D reconstruction
maps is through the use of Simultaneous Localization
and Mapping (SLAM), a recurrent engineering problem, mainly
in the area of robotics. It consists of building and updating a
consistent map of the unknown environment and, simultaneously,
saving the pose of the robot, or the camera, at every given time
instant. A variety of algorithms has been proposed to address
this problem, namely the Large Scale Direct Monocular SLAM
(LSD-SLAM), ORB-SLAM, Direct Sparse Odometry (DSO) or
Parallel Tracking and Mapping (PTAM), among others. However,
despite the fact that these algorithms provide good results, they
are computationally intensive.
Hence, in this paper, we propose a modified version of DSO
SLAM, which implements code parallelization techniques using
OpenMP, an API for introducing parallelism in C, C++ and
Fortran programs, that supports multi-platform shared memory
multi-processing programming. With this approach we propose
multiple directive-based code modifications, in order to make the
SLAM algorithm execute considerably faster. The performance
of the proposed solution was evaluated on standard datasets and
provides speedups above 40% without significant extra parallel
programming effort.info:eu-repo/semantics/publishedVersio
Geodiversity assessment of the Xingu drainage basin
Artigo com mapa em anexoGeodiversity is a recent concept that refers to the abiotic variety of nature. It is defined as the
range of geological (rocks, minerals, fossils), geomorphological (landforms, processes) and
soil features, including their assemblages, relationships, properties, interpretation and
systems. In this work, a method of quantitative assessment of geodiversity was applied to
the Xingu drainage basin (Amazoˆnia – Brazil). The method is based on the quantification
and integration of abiotic features represented on thematic maps at scales ranging from
1:250,000 to 1:2,500,000, overlaid by a 1:25,000 systematic grid. In order to calculate the
final geodiversity index, five partial numerical indices representing the main components of
geodiversity were drawn compiled: geology, geomorphology, soil, palaeontology and
mineral occurrences. The resulting Geodiversity Index map is presented in the form of five
isoline classes. The objective of this method is to present such a mapping technique as a
tool for environmental planning, particularly for the identification and definition of priority
areas for conservation.Fundação para a Ciência e a Tecnologia (FCT)CAPE
Amerindian genetic ancestry is associated with higher survival rates compared to African and European ancestry in Brazilian patients with heart failure
Statistical Workflow for Feature Selection in Human Metabolomics Data.
High-throughput metabolomics investigations, when conducted in large human cohorts, represent a potentially powerful tool for elucidating the biochemical diversity underlying human health and disease. Large-scale metabolomics data sources, generated using either targeted or nontargeted platforms, are becoming more common. Appropriate statistical analysis of these complex high-dimensional data will be critical for extracting meaningful results from such large-scale human metabolomics studies. Therefore, we consider the statistical analytical approaches that have been employed in prior human metabolomics studies. Based on the lessons learned and collective experience to date in the field, we offer a step-by-step framework for pursuing statistical analyses of cohort-based human metabolomics data, with a focus on feature selection. We discuss the range of options and approaches that may be employed at each stage of data management, analysis, and interpretation and offer guidance on the analytical decisions that need to be considered over the course of implementing a data analysis workflow. Certain pervasive analytical challenges facing the field warrant ongoing focused research. Addressing these challenges, particularly those related to analyzing human metabolomics data, will allow for more standardization of as well as advances in how research in the field is practiced. In turn, such major analytical advances will lead to substantial improvements in the overall contributions of human metabolomics investigations
An empirical evaluation of imputation accuracy for association statistics reveals increased type-I error rates in genome-wide associations
<p>Abstract</p> <p>Background</p> <p>Genome wide association studies (GWAS) are becoming the approach of choice to identify genetic determinants of complex phenotypes and common diseases. The astonishing amount of generated data and the use of distinct genotyping platforms with variable genomic coverage are still analytical challenges. Imputation algorithms combine directly genotyped markers information with haplotypic structure for the population of interest for the inference of a badly genotyped or missing marker and are considered a near zero cost approach to allow the comparison and combination of data generated in different studies. Several reports stated that imputed markers have an overall acceptable accuracy but no published report has performed a pair wise comparison of imputed and empiric association statistics of a complete set of GWAS markers.</p> <p>Results</p> <p>In this report we identified a total of 73 imputed markers that yielded a nominally statistically significant association at <it>P </it>< 10 <sup>-5 </sup>for type 2 Diabetes Mellitus and compared them with results obtained based on empirical allelic frequencies. Interestingly, despite their overall high correlation, association statistics based on imputed frequencies were discordant in 35 of the 73 (47%) associated markers, considerably inflating the type I error rate of imputed markers. We comprehensively tested several quality thresholds, the haplotypic structure underlying imputed markers and the use of flanking markers as predictors of inaccurate association statistics derived from imputed markers.</p> <p>Conclusions</p> <p>Our results suggest that association statistics from imputed markers showing specific MAF (Minor Allele Frequencies) range, located in weak linkage disequilibrium blocks or strongly deviating from local patterns of association are prone to have inflated false positive association signals. The present study highlights the potential of imputation procedures and proposes simple procedures for selecting the best imputed markers for follow-up genotyping studies.</p
Coocorrência de mutações nos genes PTPN11 e SOS1 na síndrome de Noonan: este achado prediz um fenótipo mais grave?
Noonan syndrome (NS) is an autosomal dominant disorder, with variable phenotypic expression, characterized by short stature, facial dysmorphisms and heart disease. Different genes of the RAS/MAPK signaling pathway are responsible for the syndrome, the most common are: PTPN11, SOS1, RAF1, and KRAS. The objective of this study was to report a patient with Noonan syndrome presenting mutations in two genes of RAS/MAPK pathway in order to establish whether these mutations lead to a more severe expression of the phenotype. We used direct sequencing of the PTPN11, SOS1, RAF1, and KRAS genes. We have identified two described mutations in heterozygosity: p.N308D and p.R552G in the genes PTPN11 and SOS1, respectively. The patient has typical clinical features similar to the ones with NS and mutation in only one gene, even those with the same mutation identified in this patient. A more severe or atypical phenotype was not observed, suggesting that these mutations do not exhibit an additive effect.A síndrome de Noonan (SN) é uma doença gênica autossômica dominante, com expressão clínica variável, caracterizada por baixa estatura, dismorfismos faciais e cardiopatia. Diferentes genes da via de sinalização RAS/MAPK são responsáveis pela síndrome, sendo as mais frequentes: PTPN11, SOS1, RAF1 e KRAS. O objetivo deste estudo foi relatar um paciente com SN que apresenta mutações em dois genes da via RAS/MAPK a fim de estabelecer se essas mutações levam a uma expressão mais grave do fenótipo. Utilizou-se sequenciamento direto dos genes PTPN11, SOS1, RAF1 e KRAS. Foram identificadas duas mutações em heterozigose previamente descritas: p.N308D e p.R552G nos genes PTPN11 e SOS1, respectivamente. A paciente apresenta quadro clínico típico semelhante ao dos pacientes com SN e mutação em um único gene, mesmo naqueles com a mesma mutação identificada na paciente. Não foi observado um fenótipo mais grave ou atípico na paciente, sugerindo que as mutações não apresentam um efeito aditivo
Fatal cases of Theileria annulata infection in calves in Portugal associated with neoplastic-like lymphoid cell proliferation
The authors describe 15 cases of acute lethal infection of calves (≤ 4 months of age) by the protozoan parasite Theileria annulata in the south of Portugal. Calves developed multifocal to coalescent nodular skin lesions, similar to multicentric malignant lymphoma. Infestation with ticks (genus Hyalomma) was intense. Theileria was seen in blood and lymph node smears, and Theileria annulata infection was confirmed by isolation of schizont-transformed cells and sequencing of hypervariable region 4 of the 18S rRNA gene. At necropsy, hemorrhagic nodules or nodules with a hemorrhagic halo were seen, particularly in the skin, subcutaneous tissue, skeletal and cardiac muscle, pharynx, trachea and intestinal serosa. Histologically nodules were formed by large, round, lymphoblastoid neoplastic-like cells. Immunohistochemistry (IHC) identified these cells as mostly CD3 positive T lymphocytes and MAC387 positive macrophages. A marker for B lymphocytes (CD79αcy) labelled very few cells. Theileria annulata infected cells in these nodules were also identified by IHC, through the use of two monoclonal antibodies (1C7 and 1C12) diagnostic for the parasite. It was concluded that the pathological changes observed in the different organs and tissues were caused by proliferation of schizont-infected macrophages, which subsequently stimulate a severe uncontrolled proliferation of uninfected T lymphocytes
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