How Reliable Are Ultra-Short-Term HRV Measurements during Cognitively Demanding Tasks?

Ultra-short-term HRV features assess minor autonomous nervous system variations such as variations resulting from cognitive stress peaks during demanding tasks. Several studies compare ultra-short-term and short-term HRV measurements to investigate their reliability. However, existing experiments are conducted in low cognitively demanding environments. In this paper, we propose to evaluate these measurements' reliability under cognitively demanding tasks using a near real-life setting. For this purpose, we selected 31 HRV features, extracted from data collected from 21 programmers performing code comprehension, and compared them across 18 different time frames, ranging from 3 min to 10 s. Statistical significance and correlation tests were performed between the features extracted using the larger window (3 min) and the same features extracted with the other 17 time frames. We paired these analyses with Bland-Altman plots to inspect how the extraction window size affects the HRV features. The main results show 13 features that presented at least 50% correlation when using 60-second windows. The HF and mNN features achieved around 50% correlation using a 30-second window. The 30-second window was the smallest time frame considered to have reliable measurements. Furthermore, the mNN feature proved to be quite robust to the shortening of the time resolution.

Representation Learning for Class C G Protein-Coupled Receptors Classification.

G protein-coupled receptors (GPCRs) are integral cell membrane proteins of relevance for pharmacology. The complete tertiary structure including both extracellular and transmembrane domains has not been determined for any member of class C GPCRs. An alternative way to work on GPCR structural models is the investigation of their functionality through the analysis of their primary structure. For this, sequence representation is a key factor for the GPCRs' classification context, where usually, feature engineering is carried out. In this paper, we propose the use of representation learning to acquire the features that best represent the class C GPCR sequences and at the same time to obtain a model for classification automatically. Deep learning methods in conjunction with amino acid physicochemical property indices are then used for this purpose. Experimental results assessed by the classification accuracy, Matthews' correlation coefficient and the balanced error rate show that using a hydrophobicity index and a restricted Boltzmann machine (RBM) can achieve performance results (accuracy of 92.9%) similar to those reported in the literature. As a second proposal, we combine two or more physicochemical property indices instead of only one as the input for a deep architecture in order to add information from the sequences. Experimental results show that using three hydrophobicity-related index combinations helps to improve the classification performance (accuracy of 94.1%) of an RBM better than those reported in the literature for class C GPCRs without using feature selection methods.

Massively Scalable Self-Assembly of Nano and Microparticle Monolayers via Aerosol Assisted Deposition.

An extremely rapid process for self-assembling well-ordered, nano, and microparticle monolayers via a novel aerosolized method is presented. The novel technique can reach monolayer self-assembly rates as high as 268 cm2 min-1 from a single aerosolizing source and methods to reach faster monolayer self-assembly rates are outlined. A new physical mechanism describing the self-assembly process is presented and new insights enabling high-efficiency nanoparticle monolayer self-assembly are developed. In addition, well-ordered monolayer arrays from particles of various sizes, surface functionality, and materials are fabricated. This new technique enables a 93× increase in monolayer self-assembly rates compared to the current state of the art and has the potential to provide an extremely low-cost option for submicron nanomanufacturing.

Towards an extensive set of criteria for safety and cyber-security evaluation of cyber-physical systems.

Verification and validation (V&V) are complex processes combining different approaches and incorporating many different methods including many activities. System engineers regularly face the question if their V&V activities lead to better products, and having appropriate criteria at hand for evaluation of safety and cybersecurity of the systems would help to answer such a question. Additionally, when there is a demand to improve the quality of an already managed V&V process, there is a struggle over what criteria to use in order to measure the improvement. This paper presents an extensive set of criteria suitable for safety and cybersecurity evaluation of cyberphysical systems. The evaluation criteria are agreed upon by 60 researchers from 32 academic and industrial organizations jointly working in a large-scale European research project on 13 real-world use cases from the domains of automotive, railway, aerospace, agriculture, healthcare, and industrial robotics.

Aloe Vera extract-based composite nanofibers for wound dressing applications.

Natural, biocompatible, and biodegradable composite nanofibers made of Aloe vera extract, pullulan, chitosan, and citric acid were successfully produced via Forcespinning® technology. The addition of Aloe vera extract at different weight percent loadings was investigated. The morphology, thermal properties, physical properties, and water absorption of the nanofibers were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The developed nanofiber membranes exhibited good water absorption capabilities, synergistic antibacterial activity against Escherichia coli, and promoted cell attachment and growth. Its porous and high surface area structure make it a potential candidate for wound dressing applications due to its ability to absorb excessive blood and exudates, as well as provide protection from infection while maintaining good thermal stability.

Mass segmentation of mammograms using Markov models associated with constrained clustering.

In this paper, we propose four variants of the Markov random field model by using constrained clustering for breast mass segmentation. These variants were tested with a set of images extracted from a public database. The obtained results have shown that the proposed variants, which allow to include additional information in the form of constraints to the clustering process, present better visual segmentation results than the original model, as well as a lower final energy which implies a better quality in the final segmentation. Specifically, the centroid initialization method used by our variants allows us to locate about 90% of the regions of interest that contain a mass, which subsequently with the pairwise constraints helped us recover a maximum of 93% of the masses. The segmentation results are also quantitatively evaluated using three supervised segmentation measures. These measures show that the mass segmentation quality of the proposed variants, considering the breast density level, is consistent with the corresponding segmentation annotated by specialized radiologists.

Opportunistic predation of the Roadside Hawk (Rupornis magnirostris) on alates subterranean termites (Coptotermes testaceus) in southwestern Brazilian Amazon / Depredación oportunista del halcón caminero (Rupornis magnirostris) sobre termitas subterráneas aladas (Coptotermes testaceus) en el suroeste de la Amazonía brasileña

Abstract We report the opportunistic predation of Roadside Hawk (Rupornis magnirostris - Accipitridae) on subterranean termite (Coptotermes testaceus - Rhinotermitidae). This predatory behaviour was observed during an avifauna survey in the municipality of Candeias do Jamari, Rondônia, Brazil, in the southwestern Brazilian Amazon. There was a great abundance of C. testaceus alates because of heavy rainfall. This is the season when C. testaceus colonies produce alates in large numbers to found new colonies. The Roadside Hawk stayed on its perch and captured winged termites with little energy expenditure. The bird in question appeared to take advantage of the termite mating flight to feed opportunistically on the abundant alates. Although feeding on insects by R. magnirostris is well known, this is the first documentation of feeding on termite alates.

Resumen Informamos de la depredación oportunista de Coptotermes testaceus (Rhinotermitidae) por Rupornis magnirostris (Accipitridae). Este comportamiento depredador fue observado durante un estudio de la avifauna en el municipio de Candeias do Jamari, Rondônia, Brasil, en el suroeste de la Amazonia brasileña. Había una gran abundancia de formas aladas de C. testaceus debido a las fuertes lluvias. Es el momento en que las colonias de C. testaceus producen formas aladas en gran número para fundar nuevas colonias. El aguilucho permaneció en su percha y capturó termitas aladas con poco gasto de energía. El ave en cuestión parecía aprovechar el vuelo de apareamiento de las termitas para alimentarse de forma oportunista de las abundantes termitas aladas durante los vuelos de apareamiento. Aunque la alimentación de insectos por parte de R. magnirostris es bien conocida, ésta es la primera documentación de alimentación de termitas aladas.

Intraosseous anomalous drainage: a rare case of pretibial varicose vein.

Valve failure with reflux and post-thrombotic syndrome are the factors most commonly correlated with varicose disease. Other rare etiologies can be put forward when these two main causes are ruled out. We report a case in which a young man presented chronic pain in the left tibia, varicose veins in the lower limbs and frequent occurrences of erysipelas. During investigation of the etiology of the varicose veins, radiographs and magnetic resonance imaging of the left leg were requested. These showed images suggestive of an osteolytic lesion in the tibia, but led us to the diagnosis of an intraosseous vein with anomalous drainage. This was confirmed through vascular examinations comprising Doppler venous flow measurement and phlebography. Recognition of this rare intraosseous anomaly is fundamental for proper patient management, but an intraosseous surgical approach is unnecessary.

Incompetência valvar com refluxo e síndrome pós-trombótica são os fatores mais comumente relacionados à doença varicosa. Outras raras etiologias podem ser levantadas quando essas duas principais causas são descartadas. Relatamos o caso de um homem jovem com dor crônica na tíbia esquerda, varizes em membros inferiores e erisipela de repetição. Durante investigação da etiologia das varizes foram solicitadas radiografias e ressonância da perna esquerda, que evidenciaram imagens sugestivas de uma lesão osteolítica na tíbia, mas que nos levaram ao diagnóstico de veia intraóssea com drenagem anômala, confirmado pelos exames vasculares de dopplerfluxometria venosa e flebografia. O reconhecimento dessa rara anomalia intraóssea é fundamental para o manejo adequado do paciente, não necessita de abordagem cirúrgica intraóssea.

The influence of alignment-free sequence representations on the semi-supervised classification of class C G protein-coupled receptors: semi-supervised classification of class C GPCRs.

G protein-coupled receptors (GPCRs) are integral cell membrane proteins of relevance for pharmacology. The tertiary structure of the transmembrane domain, a gate to the study of protein functionality, is unknown for almost all members of class C GPCRs, which are the target of the current study. As a result, their investigation must often rely on alignments of their amino acid sequences. Sequence alignment entails the risk of missing relevant information. Various approaches have attempted to circumvent this risk through alignment-free transformations of the sequences on the basis of different amino acid physicochemical properties. In this paper, we use several of these alignment-free methods, as well as a basic amino acid composition representation, to transform the available sequences. Novel semi-supervised statistical machine learning methods are then used to discriminate the different class C GPCRs types from the transformed data. This approach is relevant due to the existence of orphan proteins to which type labels should be assigned in a process of deorphanization or reverse pharmacology. The reported experiments show that the proposed techniques provide accurate classification even in settings of extreme class-label scarcity and that fair accuracy can be achieved even with very simple transformation strategies that ignore the sequence ordering.

Semi-supervised analysis of human brain tumours from partially labeled MRS information, using manifold learning models.

Medical diagnosis can often be understood as a classification problem. In oncology, this typically involves differentiating between tumour types and grades, or some type of discrete outcome prediction. From the viewpoint of computer-based medical decision support, this classification requires the availability of accurate diagnoses of past cases as training target examples. The availability of such labeled databases is scarce in most areas of oncology, and especially so in neuro-oncology. In such context, semi-supervised learning oriented towards classification can be a sensible data modeling choice. In this study, semi-supervised variants of Generative Topographic Mapping, a model of the manifold learning family, are applied to two neuro-oncology problems: the diagnostic discrimination between different brain tumour pathologies, and the prediction of outcomes for a specific type of aggressive brain tumours. Their performance compared favorably with those of the alternative Laplacian Eigenmaps and Semi-Supervised SVM for Manifold Learning models in most of the experiments.

Intraosseous anomalous drainage: a rare case of pretibial varicose vein / Drenagem anômala intraóssea: um caso raro de varizes pré-tibiais

ABSTRACT Valve failure with reflux and post-thrombotic syndrome are the factors most commonly correlated with varicose disease. Other rare etiologies can be put forward when these two main causes are ruled out. We report a case in which a young man presented chronic pain in the left tibia, varicose veins in the lower limbs and frequent occurrences of erysipelas. During investigation of the etiology of the varicose veins, radiographs and magnetic resonance imaging of the left leg were requested. These showed images suggestive of an osteolytic lesion in the tibia, but led us to the diagnosis of an intraosseous vein with anomalous drainage. This was confirmed through vascular examinations comprising Doppler venous flow measurement and phlebography. Recognition of this rare intraosseous anomaly is fundamental for proper patient management, but an intraosseous surgical approach is unnecessary.

RESUMO Incompetência valvar com refluxo e síndrome pós-trombótica são os fatores mais comumente relacionados à doença varicosa. Outras raras etiologias podem ser levantadas quando essas duas principais causas são descartadas. Relatamos o caso de um homem jovem com dor crônica na tíbia esquerda, varizes em membros inferiores e erisipela de repetição. Durante investigação da etiologia das varizes foram solicitadas radiografias e ressonância da perna esquerda, que evidenciaram imagens sugestivas de uma lesão osteolítica na tíbia, mas que nos levaram ao diagnóstico de veia intraóssea com drenagem anômala, confirmado pelos exames vasculares de dopplerfluxometria venosa e flebografia. O reconhecimento dessa rara anomalia intraóssea é fundamental para o manejo adequado do paciente, não necessita de abordagem cirúrgica intraóssea.

Desarrollo de un nuevo filtro para la vena cava de acero inoxidable y titanio de fabricación nacional (Trabajo Experimental) / Development of a new inferior vena cava filter

Desarrollamos un nuevo filtro de fabricación nacional de acero inoxidable electropulido y titanio en conjunto con la industria militar y lo probamos en el laboratorio de radiología experimental. Resultó ser efectivo en el atrapamiento de coagulos marcados con medio de contraste y en los estudios anatomopatológicos tanto macroscopicos como en la microscopía se demostró adecuada biocompatibilidad y no hubo datos de rechazo. Consideramos una bena alternativa el desarrollar nuestros propios dispositivos por la carencia y alto costo de los importados