Computer Sciences

Technological Advances in microelectronic and telecommunication fields enable the existence of tiny computing units, very small and more efficient. In the context of these new technologies, Wireless Sensor Networks (WSN) have emerged. The main research objective in WSN domain is the development of algorithms and protocols ensuring minimal energy consumption. Most proposed solutions are based on one-layer stack model approach. Recently, other works tend to exploit together many layers in order to optimize energy consumption. In this paper, we propose a Cross-Layer Medium Access Control (CL-MAC) protocol using two adjacent layers (MAC and Network) to economize energy for WSN. The basic idea behind our protocol is to wake-up only nodes belonging to a routing path from the source to the base station (Sink) by exploiting routing information while other nodes leave maintained as long time as possible in a sleep mode. The protocol is modeled using a time Petri net and validated by TiNA tool. The simulation results demonstrate the effectiveness of our proposal in terms of energy consumption and latency.

Background: Comparative studies on the use of meshes and acellular dermal matrices (ADM) in implant-based breast reconstruction (IBBR) have not yet been performed. Methods: This prospective, randomized, controlled, multicenter pilot study was performed at four Austrian breast cancer centers. 50 patients with oncologic or prophylactic indication for mastectomy and IBBR were randomized to immediate IBBR with either an ADM (Protexa®) or a titanized mesh (TiLOOP® Bra). Complications, failed reconstruction, cosmetic outcome, patients' quality of life and the thickness of the overlying tissue were recorded immediately postoperatively and three and six months after surgery. Results: 48 patients participated in the study (Protexa® group: 23; TiLOOP® Bra group: 25 patients). The overall complication rate was 31.25% with similar rates in both groups (Protexa® group nine vs. TiLOOP® Bra group six; p=0.188). There was a higher incidence of severe complications leading to failed reconstructions with implant loss in the Protexa® group than in the TiLOOP® Bra group (seven vs. two; p<0.0001). An inverted T-incision technique led to significantly more complications and reconstructive failure with Protexa® (p=0.037, p=0.012, respectively). There were no significant differences in patients' satisfaction with cosmetic results (p=0.632), but surgeons and external specialists graded significantly better outcomes with TiLOOP® Bra (p=0.034, p=0.032). This pilot study showed use of TiLOOP® Bra or Protexa® in IBBR and was feasible leading to good cosmetic outcomes and high patient satisfaction. To validate the higher failure rates in the Protexa® group, data from a larger trial were required. Daphne Gschwantler-Kaulich has completed her specialization in Obstetrics and Gynaecology at the Medical University of Vienna, Austria, in 2009 with further specialization in Senology, Hereditary Breast Cancer and Breast Reconstruction. She has published more than 30 papers in reputed journals.