From pixels to gestures: learning visual representations for human analysis in color and depth data sequences

[cat] L’anàlisi visual de persones a partir d'imatges és un tema de recerca molt important, atesa la rellevància que té a una gran quantitat d'aplicacions dins la visió per computador, com per exemple: detecció de vianants, monitorització i vigilància,interacció persona-màquina, “e-salut” o sistemes de recuperació d’matges a partir de contingut, entre d'altres. En aquesta tesi volem aprendre diferents representacions visuals del cos humà, que siguin útils per a la anàlisi visual de persones en imatges i vídeos. Per a tal efecte, analitzem diferents modalitats d'imatge com són les imatges de color RGB i les imatges de profunditat, i adrecem el problema a diferents nivells d'abstracció, des dels píxels fins als gestos: segmentació de persones, estimació de la pose humana i reconeixement de gestos. Primer, mostrem com la segmentació binària (objecte vs. fons) del cos humà en seqüències d'imatges ajuda a eliminar soroll pertanyent al fons de l'escena en qüestió. El mètode presentat, basat en optimització “Graph cuts”, imposa consistència espai-temporal a Ies màscares de segmentació obtingudes en “frames” consecutius. En segon lloc, presentem un marc metodològic per a la segmentació multi-classe, amb la qual podem obtenir una descripció més detallada del cos humà, en comptes d'obtenir una simple representació binària separant el cos humà del fons, podem obtenir màscares de segmentació més detallades, separant i categoritzant les diferents parts del cos. A un nivell d'abstraccíó més alt, tenim com a objectiu obtenir representacions del cos humà més simples, tot i ésser suficientment descriptives. Els mètodes d'estimació de la pose humana sovint es basen en models esqueletals del cos humà, formats per segments (o rectangles) que representen les extremitats del cos, connectades unes amb altres seguint les restriccions cinemàtiques del cos humà. A la pràctica, aquests models esqueletals han de complir certes restriccions per tal de poder aplicar mètodes d'inferència que permeten trobar la solució òptima de forma eficient, però a la vegada aquestes restriccions suposen una gran limitació en l'expressivitat que aques.ts models son capaços de capturar. Per tal de fer front a aquest problema, proposem un enfoc “top-down” per a predir la posició de les parts del cos del model esqueletal, introduïnt una representació de parts de mig nivell basada en “Poselets”. Finalment. proposem un marc metodològic per al reconeixement de gestos, basat en els “bag of visual words”. Aprofitem els avantatges de les imatges RGB i les imatges; de profunditat combinant vocabularis visuals específiques per a cada modalitat, emprant late fusion. Proposem un nou descriptor per a imatges de profunditat invariant a rotació, que millora l'estat de l'art, i fem servir piràmides espai-temporals per capturar certa estructura espaial i temporal dels gestos. Addicionalment, presentem una reformulació probabilística del mètode “Dynamic Time Warping” per al reconeixement de gestos en seqüències d'imatges. Més específicament, modelem els gestos amb un model probabilistic gaussià que implícitament codifica possibles deformacions tant en el domini espaial com en el temporal.[eng] The visual analysis of humans from images is an important topic of interest due to its relevance to many computer vision applications like pedestrian detection, monitoring and surveillance, human-computer interaction, e-health or content-based image retrieval, among others. In this dissertation in learning different visual representations of the human body that are helpful for the visual analysis of humans in images and video sequences. To that end, we analyze both RCB and depth image modalities and address the problem from three different research lines, at different levels of abstraction; from pixels to gestures: human segmentation, human pose estimation and gesture recognition. First, we show how binary segmentation (object vs. background) of the human body in image sequences is helpful to remove all the background clutter present in the scene. The presented method, based on “Graph cuts” optimization, enforces spatio-temporal consistency of the produced segmentation masks among consecutive frames. Secondly, we present a framework for multi-label segmentation for obtaining much more detailed segmentation masks: instead of just obtaining a binary representation separating the human body from the background, finer segmentation masks can be obtained separating the different body parts. At a higher level of abstraction, we aim for a simpler yet descriptive representation of the human body. Human pose estimation methods usually rely on skeletal models of the human body, formed by segments (or rectangles) that represent the body limbs, appropriately connected following the kinematic constraints of the human body, In practice, such skeletal models must fulfill some constraints in order to allow for efficient inference, while actually Iimiting the expressiveness of the model. In order to cope with this, we introduce a top-down approach for predicting the position of the body parts in the model, using a mid-level part representation based on Poselets. Finally, we propose a framework for gesture recognition based on the bag of visual words framework. We leverage the benefits of RGB and depth image modalities by combining modality-specific visual vocabularies in a late fusion fashion. A new rotation-variant depth descriptor is presented, yielding better results than other state-of-the-art descriptors. Moreover, spatio-temporal pyramids are used to encode rough spatial and temporal structure. In addition, we present a probabilistic reformulation of Dynamic Time Warping for gesture segmentation in video sequences, A Gaussian-based probabilistic model of a gesture is learnt, implicitly encoding possible deformations in both spatial and time domains

Pharmacological Potential of Lathyrane-Type Diterpenoids from Phytochemical Sources

Lathyrane diterpenoids are one of the primary types of secondary metabolites present in the genus Euphorbia and one of the largest groups of diterpenes. They are characterized by having a highly oxygenated tricyclic system of 5, 11 and 3 members. These natural products and some synthetic derivatives have shown numerous interesting biological activities with clinical potential against various diseases, such as cytotoxic activity against cancer cell lines, multi-drug resistance reversal, antiviral properties, anti-inflammatory activity and their capability to induce proliferation or differentiation into neurons of neural progenitor cells. The structure of the lathyrane skeleton could be considered privileged because its framework is able to direct functional groups in a well-defined space. The favorable arrangement of these makes interaction possible with more than one target. This review aims to highlight the evidence of lathyranes as privileged structures in medicinal chemistry. Chemical structures of bioactive compounds, the evaluation of biological properties of natural and semisynthetic derivatives, and the exploration of the mechanisms of action as well as target identification and some aspects of their targeted delivery are discussed

A fully-automatic caudate nucleus segmentation of brain MRI: Application in volumetric analysis of pediatric attention-deficit/hyperactivity disorder

Background Accurate automatic segmentation of the caudate nucleus in magnetic resonance images (MRI) of the brain is of great interest in the analysis of developmental disorders. Segmentation methods based on a single atlas or on multiple atlases have been shown to suitably localize caudate structure. However, the atlas prior information may not represent the structure of interest correctly. It may therefore be useful to introduce a more flexible technique for accurate segmentations. Method We present Cau-dateCut: a new fully-automatic method of segmenting the caudate nucleus in MRI. CaudateCut combines an atlas-based segmentation strategy with the Graph Cut energy-minimization framework. We adapt the Graph Cut model to make it suitable for segmenting small, low-contrast structures, such as the caudate nucleus, by defining new energy function data and boundary potentials. In particular, we exploit information concerning the intensity and geometry, and we add supervised energies based on contextual brain structures. Furthermore, we reinforce boundary detection using a new multi-scale edgeness measure. Results We apply the novel CaudateCut method to the segmentation of the caudate nucleus to a new set of 39 pediatric attention-deficit/hyperactivity disorder (ADHD) patients and 40 control children, as well as to a public database of 18 subjects. We evaluate the quality of the segmentation using several volumetric and voxel by voxel measures. Our results show improved performance in terms of segmentation compared to state-of-the-art approaches, obtaining a mean overlap of 80.75%. Moreover, we present a quantitative volumetric analysis of caudate abnormalities in pediatric ADHD, the results of which show strong correlation with expert manual analysis. Conclusion CaudateCut generates segmentation results that are comparable to gold-standard segmentations and which are reliable in the analysis of differentiating neuroanatomical abnormalities between healthy controls and pediatric ADHD

A study of the osmotic membrane bioreactor process using a sodium chloride solution and an industrial effluent as draw solutions

[EN] Osmotic membrane bioreactor (OMBR) is an emerging membrane process which has gained interest in the recent years because of the low energy consumption and the high effluent quality. The osmotic membrane bioreactor combines a forward osmosis (FO) membrane and a biological treatment. However, salt reverse flux is the main problem because of the negative effect of the salt concentration increase in the reactor on the microbial activity. This is the reason why the study of a suitable draw solution (DS) is very important in the overall performance of the reactor. This study compares the process performance using two draw solutions: a 53 g L-1 NaCI solution and a real waste water solution (waste water from an absorption column consisting mainly of SO42- and NH4-N with concentrations of 153 g L-1 and 19 g L-1, respectively). The comparison is focused on the salt reverse flux during the reactor operation, the mixed liquor characteristics, the membrane fouling and the overall performance. The results indicated that the industrial wastewater showed a higher salt reverse flux, but also a less severe fouling and a higher the osmotic pressure difference in comparison with the NaCl solution. In terms of chemical oxygen demand (COD) removal efficiencies, both draw solutions attained values higher than 80%, though the efficiency was slightly lower when the industrial effluent was used as DS. This was related to the higher conductivity reached in the bioreactor when the industrial effluent was used as draw solution. In spite of it, the use of this industrial effluent as draw solution is strongly recommended because of the high permeate fluxes yielded, the low membrane fouling and the lack of necessity of regenerating the draw solution. (C) 2017 Elsevier B.V. All rights reserved.This study was supported by the Spanish Ministry of Economy and Competitiveness (Spain) through the project RTC-2015-3582-5-AR.Lujan Facundo, MJ.; Soler Cabezas, JL.; Mendoza Roca, JA.; Vincent Vela, MC.; Bes-Piá, M.; Doñate Hernández, S. (2017). A study of the osmotic membrane bioreactor process using a sodium chloride solution and an industrial effluent as draw solutions. Chemical Engineering Journal. 322:603-610. doi:10.1016/j.cej.2017.04.062S60361032

Evaluation of serum omentin-1 and apelin concentrations in patients with hidradenitis suppurativa

Introduction: Recent studies suggest a role of adipokines in the pathogenesis of hidradenitis suppurativa (HS). Omentin-1 and apelin are two recently identified adipokines that have been involved in the regulation of metabolic and inflammatory responses. Aim: To investigate serum omentin-1 and apelin levels in patients with HS and to assess their associations with metabolic parameters, disease severity and HS risk. Material and methods: This case-control study included 139 non-diabetic individuals (78 HS patients and 61 ageand sex-matched controls). Serum concentrations of omentin-1 and apelin and the homeostasis model assessment of insulin resistance (HOMA-IR) were measured in all participants. Results: Serum omentin-1 concentrations were significantly higher in HS patients compared to controls, whereas apelin serum levels did not significantly differ between both groups. These differences in omentin-1 concentrations remained significant even after adjusting for age, sex, and body mass index (BMI). The results of logistic regression analysis showed that increased omentin-1 plasma levels were an independent risk factor for HS. However, we found no association between serum levels of both omentin-1 and apelin with HS severity. Conclusions: Our results show that patients with HS have raised omentin-1 serum levels, which are associated with HS risk

Profile and characteristics of the adequacy of blood transfusions in Trauma Intensive Care. A cross sectional multicenter study

IntroductionMajor trauma is one of the major health care problems facing modern society, trauma systems require careful planning to achieve an ideal level of coverage for the population. The Patient Blood Management Program is an integrated and global strategy to provide patient care that aims to assess and address, when possible, the etiology of blood abnormalities rather than transfuse without treating the underlying cause. We aimed to describe the factors that are associated with the clinical decision to transfuse polytraumatized patients admitted to the Intensive Care Unit (ICU).MethodWe performed a cross sectional multicenter study of patients admitted to ICUs for trauma in 14 Spanish hospitals from September 2020 to December 2021.ResultsA total of 69 patients were treated in the emergency room due to polytrauma, 46% of them were considered serious in the initial triage. Thirty were caused by a fall from considerable height (43.47%), followed by 39 patients admitted due to trac accidents (56.52%). The location of the trauma was mainly cranioencephalic, followed by thoracic trauma. Of the 69 patients, 25 received a blood transfusion during their ICU stay (36.23%).DiscussionNo significant differences were observed between transfused and non-transfused patients, except for the severity scales, where transfused patients have a higher score on all the scales assessed in the ICU except for the Revised Trauma Score. As we can see, the incidence of kidney failure was also different between the groups analyzed, reaching 44.00% in transfused patients and 13.64% in the group of patients without blood transfusion, p = 0.005. In this sense, 92.00% of the transfusions performed were inadequate according to the criteria of Hb in blood prior to the decision to transfuse (Hb < 9). Our data support the need to consider clinical practice guidelines regarding blood transfusion and its practices

Profile and characteristics of the adequacy of blood transfusions in Trauma Intensive Care. A cross sectional multicenter study

IntroductionMajor trauma is one of the major health care problems facing modern society, trauma systems require careful planning to achieve an ideal level of coverage for the population. The Patient Blood Management Program is an integrated and global strategy to provide patient care that aims to assess and address, when possible, the etiology of blood abnormalities rather than transfuse without treating the underlying cause. We aimed to describe the factors that are associated with the clinical decision to transfuse polytraumatized patients admitted to the Intensive Care Unit (ICU).MethodWe performed a cross sectional multicenter study of patients admitted to ICUs for trauma in 14 Spanish hospitals from September 2020 to December 2021.ResultsA total of 69 patients were treated in the emergency room due to polytrauma, 46% of them were considered serious in the initial triage. Thirty were caused by a fall from considerable height (43.47%), followed by 39 patients admitted due to trac accidents (56.52%). The location of the trauma was mainly cranioencephalic, followed by thoracic trauma. Of the 69 patients, 25 received a blood transfusion during their ICU stay (36.23%).DiscussionNo significant differences were observed between transfused and non-transfused patients, except for the severity scales, where transfused patients have a higher score on all the scales assessed in the ICU except for the Revised Trauma Score. As we can see, the incidence of kidney failure was also different between the groups analyzed, reaching 44.00% in transfused patients and 13.64% in the group of patients without blood transfusion, p = 0.005. In this sense, 92.00% of the transfusions performed were inadequate according to the criteria of Hb in blood prior to the decision to transfuse (Hb < 9). Our data support the need to consider clinical practice guidelines regarding blood transfusion and its practices

Association of Trabecular Bone Score with Inflammation and Adiposity in Patients with Psoriasis: Effect of Adalimumab Therapy

Studies on trabecular bone score (TBS) in psoriasis are lacking. We aim to assess the association between TBS and inflammation, metabolic syndrome features, and serum adipokines in 29 nondiabetic patients with psoriasis without arthritis, before and after 6-month adalimumab therapy. For that purpose, adjusted partial correlations and stepwise multivariable linear regression analysis were performed. No correlation was found between TBS and disease severity. TBS was negatively associated with weight, BMI, waist perimeter, fat percentage, and systolic and diastolic blood pressure before and after adalimumab. After 6months of therapy, a negative correlation between TBS and insulin resistance (?? = 0.02) and leptin (?? = 0.01) and a positive correlationwith adiponectin were found (?? = 0.01).The best set of predictors for TBS values at baseline were female sex (?? = 0.015), age (?? = 0.05), and BMI (?? = 0.001). The best set of predictors for TBS following 6 months of biologic therapy were age (?? = 0.001), BMI (?? < 0.0001), and serumadiponectin levels (?? = 0.027). In conclusion, in nondiabetic patients withmoderate-to-severe psoriasis, TBS correlates with metabolic syndrome features and inflammation.This association is still present after 6 months of adalimumab therapy. Moreover, serum adiponectin levels seem to be an independent variable related to TBS values, after adalimumab therapy

A Gesture Recognition System for Detecting Behavioral Patterns of ADHD

We present an application of gesture recognition using an extension of dynamic time warping (DTW) to recognize behavioral patterns of attention deficit hyperactivity disorder (ADHD). We propose an extension of DTW using one-class classifiers in order to be able to encode the variability of a gesture category, and thus, perform an alignment between a gesture sample and a gesture class. We model the set of gesture samples of a certain gesture category using either Gaussian mixture models or an approximation of convex hulls. Thus, we add a theoretical contribution to classical warping path in DTW by including local modeling of intraclass gesture variability. This methodology is applied in a clinical context, detecting a group of ADHD behavioral patterns defined by experts in psychology/psychiatry, to provide support to clinicians in the diagnose procedure. The proposed methodology is tested on a novel multimodal dataset (RGB plus depth) of ADHD children recordings with behavioral patterns. We obtain satisfying results when compared to standard state-of-the-art approaches in the DTW context