Analyzing interference between RGB-D cameras for human motion tracking

Multi-camera RGB-D systems are becoming popular as sensor setups in Computer Vision applications but they are prone to cause interference between them, compromising their accuracy. This paper extends previous works on the analysis of the noise introduced by interference with new and more realistic camera configurations and different brands of devices. As expected, the detected noise increases as distance and angle grows, becoming worse when interference is present. Finally, we evaluate the effectiveness of the proposed solutions of using DC vibration motors to mitigate them. The results of this study are being used to assess the effect of interference when applying these setups to human motion tracking.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Plan Propio de Investigación de la UMA. Junta de Andalucía, proyecto TEP2012-53

Role of endogenous cannabinoids in the control of basal ganglia activity

The cannabinoid system is a novel intercellular signaling system that plays a prominent role, among others, in the control of basal ganglia function. This finding can be concluded from the data obtained in different series of anatomical, biochemical, electrophysiological and pharmacological studies. These data demonstrated: (i) that the basal ganglia contain high levels of endocannabinoids and their receptors, mainly including the cannabinoid CB1 receptor subtype but also a related receptor type, the vanilloid TRPV1 receptor; (ii) that the activation or the blockade of this system produces important changes in motor behavior, changes that are originated as a consequence of interactions of the cannabinoid system with various classic neurotransmitters such as GABA, dopamine or glutamate; and (iii) the occurrence of marked changes in specific elements of the cannabinoid signaling system in various basal ganglia disorders, with emphasis in the induction/upregulation of the cannabinoid CB2 receptor subtype. This large evidence relating endocannabinoids and their receptors to the function of the basal ganglia, both in the healthy and the pathological brain, has provided support for the idea that cannabinoid-based medicines, with selectivity for different targets of the cannabinoid signaling system (synthetic enzymes, receptors, inactivation system), might have therapeutic potential to alleviate symptoms and/or provide neuroprotection in basal ganglia disorders, in particular Parkinson´s disease and Huntington´s chorea. The present chapter will review the knowledge on this issue trying to establish the future lines for the research on the therapeutic potential of the cannabinoid signaling system in basal ganglia disorders.peer-reviewe

Promoting light hydrocarbons yield by catalytic hydrodechlorination of residual chloromethanes using palladium supported on zeolite catalysts

Gas catalytic hydrodechlorination (HDC) of trichloromethane (TCM) and dichloromethane (DCM) was analyzed using Pd (1 wt.%) on different zeolites as catalysts. The aim of this study was to know the surface properties of the catalysts and reaction conditions that promote the yield to light hydrocarbons in this reaction. Five different zeolite supports were used from three commercial zeolites (KL, L-type; NaY, Faujasite; H-MOR, Mordenite). KL and NaY were submitted to ionic exchange treatments in order to increase their acidity and analyze the effect of the acidity in the activity and selectivity of the HDC reaction. Exchanged zeolites (HL and HY) showed the highest Pd dispersion due to their higher surface acidity. The best TCM/DCM conversion and selectivity to light hydrocarbons was obtained using the two non-exchanged zeolite-catalysts, KL and NaY. Low surface acidity seems to be the key aspect to promote the formation of light hydrocarbons. The formation of these products is favored at high reaction temperatures and low H2: chloromethane ratios. KL showed the highest selectivity to olefins (60%), although with a lower dechlorination degree. Non-exchanged NaY catalyst showed high selectivity to paraffins (70% and 95% for the HDC of DCM and TCM, respectively)Authors gratefully acknowledge financial support from FEDER/Ministerio de Ciencia, Innovación y Universidades—Agencia Estatal de Investigación/ CTM2017-85498-R. C. Fernández Ruiz acknowledges MINECO for his research gran

Exploiting Spatio-Temporal Coherence for Video Object Detection in Robotics

This paper proposes a method to enhance video object detection for indoor environments in robotics. Concretely, it exploits knowledge about the camera motion between frames to propagate previously detected objects to successive frames. The proposal is rooted in the concepts of planar homography to propose regions of interest where to find objects, and recursive Bayesian filtering to integrate observations over time. The proposal is evaluated on six virtual, indoor environments, accounting for the detection of nine object classes over a total of ∼ 7k frames. Results show that our proposal improves the recall and the F1-score by a factor of 1.41 and 1.27, respectively, as well as it achieves a significant reduction of the object categorization entropy (58.8%) when compared to a two-stage video object detection method used as baseline, at the cost of small time overheads (120 ms) and precision loss (0.92).</p

Frecuencia de erupcion temprana de caninos y premolares permanentes en niños de 8-10 años, en ocho colegios del distrito V de Managua, Nicaragua, octubre - diciembre 2015

Tesis(Cirujano Dentista)--Universidad Americana, Managua,2016En el presente estudio fueron examinados un total de 783 niños de 8 colegios del distrito V de la ciudad de Managua, Nicaragua en el periodo de octubre-diciembre del año 2015, de los cuales los que reunieron las características definidas de acuerdo a los criterios de inclusión adoptados para este estudio fueron 772 niños, de los cuales 389 niños son del sexo femenino y 383 del sexo masculino

Robot@VirtualHome, an ecosystem of virtual environments and tools for realistic indoor robotic simulation

Simulations and synthetic datasets have historically empower the research in different service robotics-related problems, being revamped nowadays with the utilization of rich virtual environments. However, with their use, special attention must be paid so the resulting algorithms are not biased by the synthetic data and can generalize to real world conditions. These aspects are usually compromised when the virtual environments are manually designed. This article presents Robot@VirtualHome, an ecosystem of virtual environments and tools that allows for the management of realistic virtual environments where robotic simulations can be performed. Here “realistic” means that those environments have been designed by mimicking the rooms’ layout and objects appearing in 30 real houses, hence not being influenced by the designer’s knowledge. The provided virtual environments are highly customizable (lighting conditions, textures, objects’ models, etc.), accommodate meta-information about the elements appearing therein (objects’ types, room categories and layouts, etc.), and support the inclusion of virtual service robots and sensors. To illustrate the possibilities of Robot@VirtualHome we show how it has been used to collect a synthetic dataset, and also exemplify how to exploit it to successfully face two service robotics-related problems: semantic mapping and appearance-based localization.This work has been supported by the research projects WISER (DPI2017-84827-R), funded by the Spanish Government and financed by the European Regional Development’s funds (FEDER), ARPEGGIO (PID2020-117057GB-I00), funded by the European H2020 program, by the grant number FPU17/04512 and the UG PHD scholarship pro-gram from the University of Groningen. We gratefully acknowledge the support of NVIDIA Corporation with the donation of the Titan X Pascal used for this research. We would like to thank the Center for Information Technology of the University of Groningen for their support and for providing access to the Peregrine high performance computing cluste

The negative effects of short-term extreme thermal events on the seagrass Posidonia oceanica are exacerbated by ammonium additions

Global warming is increasingly affecting our biosphere. However, in addition to global warming, a panoply of local stressors caused by human activities is having a profound impact on our environment. The risk that these local stressors could modify the response of organisms to global warming has attracted interest and fostered research on their combined effect, especially with a view to identifying potential synergies. In coastal areas, where human activities are heavily concentrated, this scenario is particularly worrying, especially for foundation species such as seagrasses. In this study we explore these potential interactions in the seagrass Posidonia oceanica. This species is endemic to the Mediterranean Sea. It is well known that the Mediterranean is already experiencing the effects of global warming, especially in the form of heat waves, whose frequency and intensity are expected to increase in the coming decades. Moreover, this species is especially sensitive to stress and plays a key role as a foundation species. The aim of this work is thus to evaluate plant responses (in terms of photosynthetic efficiency and growth) to the combined effects of short-term temperature increases and ammonium additions.To achieve this, we conducted a mesocosm experiment in which plants were exposed to three thermal treatments (20°C, 30°C and 35°C) and three ammonium concentrations (ambient, 30 μM and 120 μM) in a full factorial experiment. We assessed plant performance by measuring chlorophyll fluorescence variables (maximum quantum yield (Fv/Fm), effective quantum yield of photosystem II (ΔF/Fm'), maximum electron transport rate (ETRmax) and non-photochemical quenching (NPQ)), shoot growth rate and leaf necrosis incidence. At ambient ammonium concentrations, P. oceanica tolerates short-term temperature increases up to 30°C. However, at 35°C, the plant loses functionality as indicated by a decrease in photosynthetic performance, an inhibition of plant growth and an increase of the necrosis incidence in leaves. On the other hand, ammonium additions at control temperatures showed only a minor effect on seagrass performance. However, the combined effects of warming and ammonium were much worse than those of each stressor in isolation, given that photosynthetic parameters and, above all, leaf growth were affected. This serves as a warning that the impact of global warming could be even worse than expected (based on temperature-only approaches) in environments that are already subject to eutrophication, especially in persistent seagrass species living in oligotrophic environments

Radionuclides in arctic marine macroalgae from Kongsfjorden (Svalbard)

Seaweeds are known to be useful environmental bioindicators since they bioaccumulate radioisotopes at very low environmental concentrations. Levels of natural radionuclides in six ecologically relevant brown and red seaweed species from Arctic coasts (Kongsfjorden, Spitsbergen, Svalbard Islands) were analysed in the present study, in order to characterise the levels of natural radioactivity in this ecosystem and to compare this with previously published data in coastal areas from other latitudes. Thalli were collected by SCUBA divers at different depths in Hansneset in September 2014 and transported immediately to the laboratory. Young thalli, free from macroscopic epibiota, were dried, powdered and confined in a standard geometry before gamma spectrometry measurements. Then, the radioactivity of 7Be, 40K, 208Tl, 210Pb, 212Pb, 226Ra and 228Ra was measured by high-resolution gamma spectrometry using high-purity germanium detectors for 172800 s. Detectors were calibrated using a traceable multi gamma standard source and results are on a dry weight and fresh weight basis and are decay corrected to the date of sampling. Our results revealed the influence of cosmogenic radionuclides in the intertidal zone, as shown by the unique presence of 7Be in the brown macroalga Fucus distichus, the only analysed species inhabiting the intertidal. High concentrations of 40K were observed in all species, as this is one of the essential elements in biota. Remarkably is the high content of 210Pb in the red seaweeds Phycodrys rubens and Ptilota gunneri, suggesting that these species might possess a higher capacity for heavy metals bioaccumulation than the analysed brown seaweeds

Three-dimensional assessment of the judo throwing techniques frequently used in competition

Background and Study Aim: Although the judo throwing techniques are not considered as injurious to the attacker, repetition of these techniques might cause repetitive strain type injuries. The goal of the study was knowledge about the degrees of flexion and extension and abduction and adduction of the main locomotive joints, performing the most employed throwing techniques in high-level competition. Material and Methods: Two world-class judoists, under the supervision of an elite Japanese expert, performed seoi-nage, uchi-mata, osoto-gari, ouchi-gari and kouchi-gari. They were analysed using three-dimensional technology. Results: Data of performance throws obtained from expert 1 and 2 respectively were very similar. Results indicate that systematic repetition of seoi-nage, uchi-mata and o-soto-gari can produce shoulder tendon pathologies. Long-term seoi-nage and uchi-mata practice might generate epicondylitis. Judokas who have suffered anterior cruciate ligament injuries must be careful when executing techniques that demand explosive knee extension (i.e. seoi-nage) against a great resistance. Judokas are not exposed to overuse injuries when they perform ouchi-gari and kouchi-gari throws. Conclusions: Systematic practice of the most employed judo throwing techniques in high-level judo can cause injuries by overuse in the upper-body joints (shoulder, elbow). Nevertheless, the lower-body joints (knee, ankle) do not seem to be at risk of injury by overuse