Overlap Removal of Dimensionality Reduction Scatterplot Layouts

Dimensionality Reduction (DR) scatterplot layouts have become a ubiquitous visualization tool for analyzing multidimensional data items with presence in different areas. Despite its popularity, scatterplots suffer from occlusion, especially when markers convey information, making it troublesome for users to estimate items' groups' sizes and, more importantly, potentially obfuscating critical items for the analysis under execution. Different strategies have been devised to address this issue, either producing overlap-free layouts, lacking the powerful capabilities of contemporary DR techniques in uncover interesting data patterns, or eliminating overlaps as a post-processing strategy. Despite the good results of post-processing techniques, the best methods typically expand or distort the scatterplot area, thus reducing markers' size (sometimes) to unreadable dimensions, defeating the purpose of removing overlaps. This paper presents a novel post-processing strategy to remove DR layouts' overlaps that faithfully preserves the original layout's characteristics and markers' sizes. We show that the proposed strategy surpasses the state-of-the-art in overlap removal through an extensive comparative evaluation considering multiple different metrics while it is 2 or 3 orders of magnitude faster for large datasets.Comment: 11 pages and 9 figure

VisRuler: Visual Analytics for Extracting Decision Rules from Bagged and Boosted Decision Trees

Bagging and boosting are two popular ensemble methods in machine learning (ML) that produce many individual decision trees. Due to the inherent ensemble characteristic of these methods, they typically outperform single decision trees or other ML models in predictive performance. However, numerous decision paths are generated for each decision tree, increasing the overall complexity of the model and hindering its use in domains that require trustworthy and explainable decisions, such as finance, social care, and health care. Thus, the interpretability of bagging and boosting algorithms, such as random forest and adaptive boosting, reduces as the number of decisions rises. In this paper, we propose a visual analytics tool that aims to assist users in extracting decisions from such ML models via a thorough visual inspection workflow that includes selecting a set of robust and diverse models (originating from different ensemble learning algorithms), choosing important features according to their global contribution, and deciding which decisions are essential for global explanation (or locally, for specific cases). The outcome is a final decision based on the class agreement of several models and the explored manual decisions exported by users. We evaluated the applicability and effectiveness of VisRuler via a use case, a usage scenario, and a user study. The evaluation revealed that most users managed to successfully use our system to explore decision rules visually, performing the proposed tasks and answering the given questions in a satisfying way.Comment: This manuscript is currently under revie

A new Lower Cretaceous Nymphid (Insecta, Neuroptera, Nymphidae) from the Crato Formation of Brazil

The family Nymphidae Rambur 1842 (Neuroptera) has only recently been recorded from the Lower Cretaceous Crato Formation of the Chapada do Araripe, northeast Brazil, with three new genera and species. The new, exceptionally preserved nymphid Araripenymphes seldeni n. gen. et sp., comes from the Nova Olinda Member, basal unit of the Crato Formation. The new species shows some unique characteristics in wing venation, such as the cubital area, number of radial cells and RP branches, not shared by the other known genera. Key words: Araripe Basin, fossil, lacewing, Brazil, new genus and species.A Família Nymphidae Rambur 1842 (Neuroptera) foi recentemente registrada para a Formação Crato (Cretáceo Inferior), Bacia do Araripe, nordeste do Brasil, com três gêneros monotípicos. Um novo neuróptero, excepcionalmente preservado, Araripenymphes seldeni n. gen. et sp. é aqui proposto e descrito. O material é proveniente do nível de calcário laminado do Membro Nova Olinda, unidade inferior da Formação Crato. As relações morfológicas e diferenças na venação alar entre outros gêneros brasileiros e mesozóicos, também são discutidas. Palavras-chave: insetos fósseis, Neuroptera, Nymphidae, Formação Crato, Cretáceo Inferior, Bacia do Araripe

DeforestVis: Behavior Analysis of Machine Learning Models with Surrogate Decision Stumps

As the complexity of machine learning (ML) models increases and the applications in different (and critical) domains grow, there is a strong demand for more interpretable and trustworthy ML. One straightforward and model-agnostic way to interpret complex ML models is to train surrogate models, such as rule sets and decision trees, that sufficiently approximate the original ones while being simpler and easier-to-explain. Yet, rule sets can become very lengthy, with many if-else statements, and decision tree depth grows rapidly when accurately emulating complex ML models. In such cases, both approaches can fail to meet their core goal, providing users with model interpretability. We tackle this by proposing DeforestVis, a visual analytics tool that offers user-friendly summarization of the behavior of complex ML models by providing surrogate decision stumps (one-level decision trees) generated with the adaptive boosting (AdaBoost) technique. Our solution helps users to explore the complexity vs fidelity trade-off by incrementally generating more stumps, creating attribute-based explanations with weighted stumps to justify decision making, and analyzing the impact of rule overriding on training instance allocation between one or more stumps. An independent test set allows users to monitor the effectiveness of manual rule changes and form hypotheses based on case-by-case investigations. We show the applicability and usefulness of DeforestVis with two use cases and expert interviews with data analysts and model developers.Comment: This manuscript is currently under revie

Gastrointestinal Tuberculosis Mimicking Crohn’s Disease

We present the case of a 24-year-old woman with complaints of abdominal pain, bloody diarrhea, and weight loss for 3 months. An outpatient colonoscopy revealed scattered ulcers, suggestive of Crohn's disease (CD). Histopathology also favored the diagnosis of CD. However, after admission to our hospital for further investigation, a chest radiograph revealed pulmonary cavitations. A computed tomography scan suggested the diagnosis of active pulmonary tuberculosis (TB). Therefore, a bronchofibroscopy, a total colonoscopy with ileoscopy, and an upper endoscopy were performed. Not only were acid-fast bacilli present in both bronchoalveolar lavage fluid and gastric juice, but also in colonic biopsies. A complete resolution of gastrointestinal symptoms was achieved 2 weeks after starting anti-TB drugs.info:eu-repo/semantics/publishedVersio

A new Lower Cretaceous Nymphid (Insecta, Neuroptera, Nymphidae) from the Crato Formation of Brazil

A Família Nymphidae Rambur 1842 (Neuroptera) foi recentemente registrada para a Formação Crato (Cretáceo Inferior), Bacia do Araripe, nordeste do Brasil, com três gêneros monotípicos. Um novo neuróptero, excepcionalmente preservado, Araripenymphes seldeni n. gen. et sp. é aqui proposto e descrito. O material é proveniente do nível de calcário laminado do Membro Nova Olinda, unidade inferior da Formação Crato. As relações morfológicas e diferenças na venação alar entre outros gêneros brasileiros e mesozóicos, também são discutidas. Palavras-chave: insetos fósseis, Neuroptera, Nymphidae, Formação Crato, Cretáceo Inferior, Bacia do Araripe.The family Nymphidae Rambur 1842 (Neuroptera) has only recently been recorded from the Lower Cretaceous Crato Formation of the Chapada do Araripe, northeast Brazil, with three new genera and species. The new, exceptionally preserved nymphid Araripenymphes seldeni n. gen. et sp., comes from the Nova Olinda Member, basal unit of the Crato Formation. The new species shows some unique characteristics in wing venation, such as the cubital area, number of radial cells and RP branches, not shared by the other known genera. Key words: Araripe Basin, fossil, lacewing, Brazil, new genus and species

Los contratos internacionales de transporte internacional marítimo de mercancías en el ordenamiento jurídico brasileño

This study analyses the International Contract for the International Carriage of Goods by Sea (Maritime Transportation of Goods) in Brazilian Law and emphasizes the problem of competence in jurisdiction and the applicable current law. Since International Law disposes that that obligations will be qualified and acquainted and forced to the National Law of the place where the contract was celebrated; it exists, in Brazil, restrictions to the autonomous will of parties for the constitution of international contracts. Acknowledging these facts, this article analyses this kind of contracts and the responsibilities the parties must assume when there’s damages, all of this having into account Brazilians legislation.El presente estudio analiza el contrato marítimo internacional del transporte de mercancías en el derecho brasileño y destaca, esencialmente, el problema de la legislación aplicable y de la competencia de jurisdicción, destacando la tendencia de la jurisprudencia y de la doctrina. En Brasil, existen restricciones al principio de la autonomía de la voluntad en los contratos internacionales que incide directamente sobre la regla del Derecho internacional privado respecto de la ley aplicable a los contratos. En general, dispone que las obligaciones serán calificadas y regidas por la ley del país en que se constituyen. La falta de la elección de una ley o cuando ésta es invalida, tendrá valor la lex fori en la cual se desarrolla el proceso que determinará la ley aplicable al contrato. Destacadas las restricciones, se busca analizar los contratos internacionales marítimos de transportes de mercancías y responsabilidades del transportador marítimo por las averías de la carga en el marco de incidencia de la legislación brasileña

Risk factors for the emergence of multidrug-resistant organisms in liver cirrhosis

Comunicação oral premiada a nível europeu durante a United Gastroenterology Week 2018, com a NationalScholar Award, prémio destinado a jovens investigadores com < 35 anosinfo:eu-repo/semantics/publishedVersio