The persistence of human immunodeficiency virus type 1 (HIV-1) infection may be in part attributed to its ability to evolve to evade neutralizing antibody (NAb) surveillance. We have tested the prediction that positive selection of V3 is positively correlated with the strength of a patient's NAb response by analyzing a data set containing both sequences from the principal neutralizing domain of HIV-1 (V3) and measures of the strength of the NAb responses of several patients. Only viral sequences from the patient with the strongest NAb response exhibited evidence of significant positive selection. To investigate the nature of selection by NAbs, we simulated the evolution of V3 at the nucleotide level. Two forms of plausible NAb selection were used: negative frequency-dependent selection and negative viral-age-dependent selection. Assuming negative age-dependent selection rather than negative frequency-dependent selection better simulated the temporal pattern of V3 variation from the patient with the strongest NAb response.

It is crucial to monitor the levels of Non-Ionizing Radiation (NIR) to which the general population may be exposed and compare them to the limits defined in the current standards, in view of the rapid rise of communication services and the prospects of a connected society. A high number of people visits shopping malls and since these locations usually have several indoor antennas close to the public, it is therefore a kind of place that must be evaluated. Thus, this work presents measurements of the electric field in a shopping mall located in Natal, Brazil. We proposed a set of six measurement points, following two criteria: places with great the flow of people and the presence of one or more Distributed Antenna System (DAS), co-sited or not with WiFi access points. Results are presented and discussed in terms of the distance to DAS (conditions: near and far) and flow density of people in the mall (scenarios: low and high number of people). The highest peaks of electric field measured were 1.96 and 3.26 V/m, respectively corresponding to 5% and 8% of the limits defined by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) and the Brazilian National Telecommunication Agency (ANATEL).