Active learning in the detection of anomalies in cryptocurrency transactions

The cryptocurrency market has grown significantly, and this quick growth has given rise to scams. It is necessary to put fraud detection mechanisms in place. The challenge of inadequate labeling is addressed in this work, which is a barrier to the training of high-performance supervised classifiers. It aims to lessen the necessity for laborious and time-consuming manual labeling. Some unlabeled data points have labels that are more pertinent and informative for the supervised model to learn from. The viability of utilizing unsupervised anomaly detection algorithms and active learning strategies to build an iterative process of acquiring labeled transactions in a cold start scenario, where there are no initial-labeled transactions, is being investigated. Investigating anomaly detection capabilities for a subset of data that maximizes supervised models’ learning potential is the goal. The anomaly detection algorithms under performed, according to the results. The findings underscore the need that anomaly detection algorithms be reserved for situations involving cold starts. As a result, using active learning techniques would produce better outcomes and supervised machine learning model performance.FCT - Fundação para a Ciência e a Tecnologia(UIDB/00319/2020

Influence of ohmic heating on production of whey protein aggregates

Ohmic Heating (OH) and its associated non-thermal effects due to the presence of an electrical field and frequency has been triggering the use of this technology for whey protein functionalization. Whey proteins have increasingly been used as functional ingredients in several food formulations presenting high nutritional and biological value (i.e., digestibility, amino acid pattern, and sensory characteristics). The purpose of this study was to characterize early steps of whey protein isolate denaturation and aggregation kinetics under the influence of OH treatments by combining different thermal and electrical effects. A multivariate characterization was performed in order to identify a global pattern in denaturation behaviour of WPI under OH applied by linking different structural stages, such as protein unfolding, exposure of protein hydrophobic core, loss of protein solubility and formation of protein aggregates. Results shows that exposure of reactive free thiol groups involved in molecular unfolding of β-lactoglobulin (β- lg) can be reduced from 10 to 20 % with OH. The presence of a moderate electric field (up to 12 V/cm) during heating also contributes to a change in the protein aggregation kinetics, as well as in the shape of the produced whey aggregates. Size growth was significantly reduced from 178 nm to 25 nm (p < 0.05) under influence of OH and transmission electron microscopy (TEM) discloses the appearance of β-lg small fibrillar aggregates upon the influence of OH. As conclusion, OH and its capability of fast heating coupled with treatments under relatively low electrical field strength, contributed to a synergistic effect yielding protein solutions with less protein aggregates and high amount of soluble proteins during early stages of heating. These fibril aggregates have a recognized potential to form physical gels, acting as thickeners or gelling agents in foods, and can be also used for encapsulation of bioactive ingredients. OH provide a novel method for production of a whey protein matrix with distinctive features and gel-forming properties

Study of Intelligent Control Techniques Applied to a Stirring Tank with Heat Exchanger

This work presents a study and evaluation of intelligent control techniques applied to the problem of temperature control of a stirring tank with heat exchanger. This problem is represented by the example provided and documented by MathWorks in MATLAB/Simulink software, called Heatex. The intelligent techniques used are Fuzzy Logic Controller (FLC), Fuzzy Cognitive Maps (FCM), Artificial Neural Networks (ANN) and the combination of these. The proportional-integral (PI) controller provided in the Heatex example is considered as a reference basis during the evaluation of the intelligent control techniques in different test scenarios. The metrics Integral of Absolute Error (IAE) and Integral Time-weighted Absolute Error (ITAE), as well as the parameters overshoot percentage and settling time are the criteria used to evaluate the control techniques performance

Analise multivariada de atributos microbiológicos e químicos do solo em cafeeiro conilon sob manejo orgânico e convencional.

O cultivo de Coffea sp. utilizando o manejo convencional e orgânico abrange grandes áreas, entretanto, há falta de informação sobre a sustentabilidade dessas formas de cultivo. No presente trabalho, teve-se por objetivo realizar uma análise conjunta das características químicas e microbiológicas do solo cultivado com cafeeiros Conilon (C. canephora) em manejo orgânico e convencional. Foram selecionadas duas áreas cultivadas com café Conilon (manejo orgânico e convencional) e uma área de fragmento de Mata Atlântica, utilizada como referência. Realizou-se análise química, granulométrica, carbono e nitrogênio da biomassa microbiana e atividade respiratória de microrganismos do solo, em janeiro e julho, na profundidade de O a 10 cm e 10 a 20 cm. Os dados foram submetidos à análise multivariada das variáveis. O carbono da biomassa microbiana foi o atributo microbiológico do solo que mais contribuiu para agrupar as diferentes formas de cultivo. O solo da Mata Atlântica seguido pelo do café Conilon sob manejo orgânico apresentaram os melhores índices da qualidade do solo. Há certa divergência entre os manejos de café orgânico e convencional e uma maior proximidade do manejo do café Conilon orgânico com o fragmento de Mata Atlântica de referência, o que permite sugerir que o manejo orgânico é mais sustentável

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%–18% 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

Nutritional status and functional capacity of hospitalized elderly

Background: The nutritional status of the aging individual results from a complex interaction between personal and environmental factors. A disease influences and is influenced by the nutritional status and the functional capacity of the individual. We asses the relationship between nutritional status and indicators of functional capacity among recently hospitalized elderly in a general hospital.Methods: A cross-sectional study was done with 240 elderly (women, n = 127 and men, n = 113) hospitalized in a hospital that provides care for the public and private healthcare systems. The nutritional status was classified by the MNA (Mini Nutritional Assessment) into: malnourished, risk of malnutrition and without malnutrition (adequate). The functional autonomy indicators were obtained by the self-reported Instrumental Activity of Daily Living (IADL) and Activity of Daily Living (ADL) questionnaire. The chi-square test was used to compare the proportions and the level of significance was 5%.Results: Among the assessed elderly, 33.8% were classified as adequate regarding nutritional status; 37.1% were classified as being at risk of malnutrition and 29.1% were classified as malnourished. All the IADL and ADL variables assessed were significantly more deteriorated among the malnourished individuals. Among the ADL variables, eating partial (42.9%) or complete (12.9%) dependence was found in more than half of the malnourished elderly, in 13.4% of those at risk of malnutrition and in 2.5% of those without malnutrition.Conclusion: There is an interrelationship between the nutritional status of the elderly and reduced functional capacity

Rarity of monodominance in hyperdiverse Amazonian forests.

Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees ≥ 10 cm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors

The Influence of the Intermittent Behavior of the Nocturnal Atmospheric Flow on the Prediction of the Diurnal Temperature Range: A Simplified Model Analysis

The variation of the atmospheric temperature near the surface associated with anthropogenic effects is analyzed using a simplified atmospheric model. Local changes in cloud cover and four different scenarios of atmospheric concentration of carbon dioxide are considered. The results show that the highest temperature variability occurs in the weak wind and decoupled state and in the transition between flow regimes. In agreement with previous efforts, the results indicate that the reduction of diurnal temperature range is related to the existence of two distinct flow regimes in the stable boundary layer. However, in the decoupled state, the occurrence of intermittent bursts of turbulence may cause temperature variations among the different scenarios to become unpredictable. It implies that it is difficult to predict the diurnal temperature range in places where low winds are common

Cognitive differentiation during childhood: A study on cognitive profiles of 5, 7, and 9-year-old children

No seio do debate sobre se a inteligência é mais bem definida por um fator geral ou por aptidões específicas, ganha relevância a hipótese da diferenciação cognitiva. Análises recentes enfatizam o interesse dessa questão para a investigação e alertam para a relevância das suas implicações na área educativa. Este estudo analisou a possibilidade de a diferenciação das aptidões cognitivas ocorrer já na infância e também o efeito moderador do Quociente de Inteligência na magnitude da relação entre as habilidades cognitivas. Aplicou-se uma bateria de provas que avaliam várias funções cognitivas a uma amostra de 231 crianças com 5, 7 e 9 anos, distribuídas por três grupos de desempenho cognitivo. Os resultados de uma análise de clusters hierárquica e de uma análise de variância apontam para a não diferenciação das funções cognitivas na infância. Contudo, uma análise mais cuidadosa aponta para alguma diferenciação suportada pela heterogeneidade dos perfis cognitivos junto dos alunos com Quociente de Inteligência elevado.Within the debate about whether intelligence is best defined by a general factor or specific skills, the hypothesis of cognitive differentiation gains relevance. Recent analyses have emphasized the importance of this issue in the investigation of cognitive skills and have highlighted its implications in education. This study examined the possibility that the differentiation of cognitive abilities may occur during childhood and investigated the moderating effect of Intelligence Quotient on the magnitude of the relationship between cognitive abilities. A battery of tests for assessing cognitive function was administered to 231 children aged 5, 7, and 9 years old, who were divided into three cognitive performance groups. The results of hierarchical cluster analysis and variance analysis indicate the lack of differentiation of cognitive functions during childhood. However, a more careful analysis suggests some differentiation supported by the heterogeneity of cognitive profiles among students with high Intelligence Quotient.FCT -Fundação para a Ciência e a Tecnologia(SFRH/BD/84153/2012