Energy-Efficient Mobile Data Collection Adopting Node Cooperation in an Underwater Acoustic Sensor Network

This paper considers an underwater acoustic sensor network with one mobile surface node to collect data from multiple underwater nodes,where the mobile destination requests retransmission from each underwater node individually employing traditional automatic-repeat-request(ARQ) protocol.We propose a practical node cooperation(NC) protocol to enhance the collection efficiency,utilizing the fact that underwater nodes can overhear the transmission of others.To reduce the source level of underwater nodes,the underwater data collection area is divided into several sub-zones,and in each sub-zone,the mobile surface node adopting the NC protocol could switch adaptively between selective relay cooperation(SRC) and dynamic network coded cooperation(DNC) .The difference of SRC and DNC lies in whether or not the selected relay node combines the local data and the data overheard from undecoded node(s) to form network coded packets in the retransmission phase.The NC protocol could also be applied across the sub-zones due to the wiretap property.In addition,we investigate the effects of different mobile collection paths,collection area division and cooperative zone design for energy saving.The numerical results showthat the proposed NC protocol can effectively save energy compared with the traditional ARQ scheme.

TBBPA rather than its main derivatives enhanced growth of endometrial cancer via p53 ubiquitination

Tetrabromobisphenol A(TBBPA)and its derivatives widely exist in various environments and biota.Although the available data indicate that TBBPA exposure is highly associated with the increased incidence of endometrial cancer(EC),the effects of TBBPA and its main derivatives on EC proliferation and the involved crucial mechanism remain unclear.The present study aimed to investigate the effects of TBBPA and its derivatives under environmental concentrations on the proliferation of EC,and the crucial mechanism on the progression of EC caused by bromine fame retardants exposure.In this research,TBBPA and two of the most common TBBPA derivatives including TBBPA bis(2-hydroxyethyl ether)(TBBPABHEE)and TBBPA bis(dibromopropyl ether)(TBBPA-BDBPE)were screened for their capacities in induced EC proliferation and explored the related mechanism by in vitro cell culture model and in vivo mice model.Under environmental concentrations,TBBPA promoted the proliferation of EC,the main derivatives of TBBPA(TBBPA-BHEE and TBBPA-BDBPE)did not present the similar facilitation effects.The ubiquitination degradation of p53 was crucial in TBBPA induced EC proliferation,which resulted in the increase of downstream cell cycle and decrease of apoptosis.The further molecular docking result suggested the high affinity between TBBPA and ubiquitinated proteasome.This finding revealed the effects of TBBPA and its derivatives on EC proliferation,thus providing novel insights into the underlying mechanisms of TBBPA-caused EC.