On Field Gesture-Based Robot-to-Robot Communication with NAO Soccer Players

Gesture-based communication is commonly used by soccer players during matches to exchange information with teammates. Among the possible forms of gesture-based interaction, hand signals are the most used. In this paper, we present a deep learning method for recognizing robot-to-robot hand signals exchanged during a soccer game. A neural network for estimating human body, face, hands, and foot position has been adapted for the application in the robot soccer scenario. Quantitative experiments carried out on NAO V6 robots demonstrate the effectiveness of the proposed approach. Source code and data used in this work are made publicly available for the community

Prevalence of human erythrovirus B19 DNA in healthy Belgian blood donors and correlation with specific antibodies against structural and non-structural viral proteins.

&lt;p&gt;&lt;b&gt;BACKGROUND AND OBJECTIVES: &lt;/b&gt;Human parvovirus (erythrovirus) B19 is recognized as a major contaminant of blood and blood products. To reduce the risk of contamination, plasma-pool screening and exclusion of highly viraemic donations are recommended. The objectives of this study were to estimate the prevalence of B19 DNA in our blood-donor population, to determine the appropriate pool size to be tested (taking into account parameters such as prevalence, viral load, test sensitivity, and the efficacy of inactivation procedures), and to correlate viral loads with the serological status of donors as regards antibodies against different viral proteins.&lt;/p&gt;&lt;p&gt;&lt;b&gt;MATERIALS AND METHODS: &lt;/b&gt;Pools of different sizes were tested for B19, using a sensitive nested polymerase chain reaction (PCR) as well as an simple, un-nested, less sensitive PCR. Positive pools were resolved to the level of individual donations, and the viral load and serological markers were determined.&lt;/p&gt;&lt;p&gt;&lt;b&gt;RESULTS: &lt;/b&gt;Of 16,859 donations, 27 (one of 625) were found to be B19 DNA positive, with viral loads ranging from 10(2) to &gt; 10(7) IU/ml. Twenty-five of the positive donations were tested for VP-specific anti-B19 antibodies, and eight (32%) were negative for both immunoglobulin (Ig)M and IgG. They were probably collected in the preseroconversion window period or from chronic carriers without detectable antibodies. We regarded the seven (28%) IgM-positive donors as being in the early phase of infection. The remaining 10 (40%) IgM-negative, IgG-positive donors were probably carriers of persistent infection (i.e. PCR positive despite the presence of IgG antibodies), as suggested by their low viral loads (&lt; 10(4) IU/ml). Fifteen out of 36 major pools contained one or more contaminated donations. Among these, 12 tested positive by nested PCR and only three by un-nested PCR, this reflecting a viral load of &gt; 10(4) IU/ml.&lt;/p&gt;&lt;p&gt;&lt;b&gt;CONCLUSIONS: &lt;/b&gt;By testing all donations as pools of 480 by un-nested PCR, and resolving positive pools to identify the responsible donations, it is possible to ensure that the viral load in fractionation pools (5000 donations) remains &lt; 10(3) IU/ml, compatible with the efficacy of inactivation procedures and complying with Food and Drug Administration (FDA) recommendations.&lt;/p&gt;</p