Seafloor geological impacts associated with drilling disturbance

This study describes the sedimentological composition and morphology of the sea bottom in an area located at 902 m depth in the Campos Basin of Brazil, and compares characteristics before and after drilling activity for oil exploration. The results show no significant sedimentological variation in the area affected by drilling. The most noticeable effects were observed during the second (MD(2)) of three cruises, in terms of change to grain size distribution, total organic carbon and clay mineral composition around the Eagle well. This impact occurred over the seabed in a direction that corresponds to the near-bottom circulation pattern, predominantly northward. In the third cruise (MD3), 12 months after drilling, some recovery was observed. Side-scan sonar imaging was used to explore the extent of the area affected by drilling, and sedimentological samples from it confirmed the effects of drilling. (C) 2008 Elsevier Ltd. All rights reserved.

A novel method for power quality multiple disturbance decomposition based on Independent Component Analysis

In this paper, a novel method for power quality signal decomposition is proposed based on Independent Component Analysis (ICA). This method aims to decompose the power system signal (voltage or current) into components that can provide more specific information about the different disturbances which are occurring simultaneously during a multiple disturbance situation. The ICA is originally a multichannel technique. However, the method proposes its use to blindly separate out disturbances existing in a single measured signal (single channel). Therefore, a preprocessing step for the ICA is proposed using a filter bank. The proposed method was applied to synthetic data, simulated data, as well as actual power system signals, showing a very good performance. A comparison with the decomposition provided by the Discrete Wavelet Transform shows that the proposed method presented better decoupling for the analyzed data. (C) 2012 Elsevier Ltd. All rights reserved.

Early skin immunological disturbance after Plasmodium-infected mosquito bites

Although the role of regulatory T cells (Tregs) during malaria infection has been studied extensively, such studies have focused exclusively on the role of Treg during the blood stage of infection; little is known about the detailed mechanisms of Tregs and sporozoite deposition in the dermis by mosquito bites. In this paper we show that sporozoites introduced into the skin by mosquito bites increase the mobility of skin Tregs and dendritic cells (DCs). We also show differences in MHC class II and/or C086 expression on skin-resident dendritic cell subtypes and macrophages. From the observed decrease of the number of APCs into draining lymph nodes, suppression of CD28 expression in conventional CD4 T cells, and a low homeostatic proliferation of skin-migrated CD4 T found in nude mice indicate that Tregs may play a fundamental role during the initial phase of malaria parasite inoculation into the mammalian host. (C) 2012 Elsevier Inc. All rights reserved.