Optimized Recovery of DNA and Subsequent Short Tandem Repeat Profiling of Different Tissues Sampled from Embalmed Human Cadavers

Introduction:Storage of specimens sampled from human remains for pathological testing,embalming for burial purposes,and for human identification often requires formalin fixation and/or paraffin embedding.Current knowledge in molecular biology techniques and forensic DNA analysis makes it possible to optimize the extraction of amplifiable DNA from formalin-fixed tissues by improving the pre-treatment,optimizing the digestion condition of proteinase K,simplifying the extraction protocol and purifying the extracted DNA with optimized volumes of alcohol.Aim:This research sought to extract amplifiable DNA from thirteen brain,bone marrow and cartilage samples from four formalin embalmed human cadavers.Materials and Methods:Brain,cartilage and bone marrow samples were taken from four different cadavers at autopsy at the Ghana Police Hospital mortuary in Accra,Ghana sixty-two days after embalming.An optimized preparation and DNA extraction protocol was carried out on all the samples.Brain samples were also taken from a non-formalin treated fifth cadaver of known STR profile,and standard DNA extraction performed to serve as positive control.Results:Our optimized protocol yielded detectable quantities of DNA from the samples when quantified with the 7500 Real-Time PCR equipment.The extracted DNA also yielded full STR profiles with varying peak heights for forensic identification purposes.The measured degradation indexes of the DNA samples were greater than 1.0,with peak heights of generated STR profiles above the limits of detection of the 3500 genetic analyzer.Conclusion:Our current study demonstrated an optimized method of DNA extraction from tissues(brain,cartilage and bone marrow)sampled from formalin embalmed human cadavers.The optimized protocol reduced the concentration of formalin fixation residues in extracted DNA from formalin-fixed tissues,thereby improving the amplification efficiency for STR profiling.Brain,bone marrow and cartilages can be a good source of DNA from embalmed and degraded human remains,though for skeletonized human remains together with teeth and long bones.

Probabilistic Modeling and Optimization of Real-Time Protocol for Multifunction Vehicle Bus

In this paper, we present the modeling and optimization of a Real-Time Protocol（RTP） used in Train Communication Networks（TCN）. In the proposed RTP, message arbitration is represented by a probabilistic model and the number of arbitration checks is minimized by using the probability of device activity. Our optimized protocol is fully compatible with the original standard and can thus be implemented easily. The experimental results demonstrate that the proposed algorithm can reduce the number of checks by about 50%, thus significantly enhancing bandwidth.

Optimal Scheduling Method in MIMO WLAN with Distributed Coordination Function

This paper addresses the optimal number of simultaneous data transmissions that maximize the system throughput in an MIMO WLAN. To facilitate simultaneous packet transmissions, both transceivers have to exchange preambles to calculate the channel state information. This exchange is combined with the RTS （request to send）/CTS （clear to send） handshake which is used to contend for the channel in WLANs. This study presents an expression for the optimal number of simultaneous data transmissions under the distributed coordinate function mechanism derived using the Markov chain model, as well as an analytical formula for the optimal system throughput given the length of the contention window and the number of nodes in the network. The analytical results show that the system throughput cannot be enhanced by simply increasing the numoer of simultaneous data transmissions.

Improving Rollback-Recovery Efficiency by Tuning Pessimism Grain

Wide-area systems are becoming a popular infrastructure for long-running applications. Rollback- recovery, as a common technology for fault tolerance and load balance, must meet the challenges of scal- ability and inherent variability in such applications. Most of the rollback-recovery protocols, however, are poor in scalability. Although pessimistic message logging protocols have no such problem, their fault-free overhead sometimes is prohibitive. Aiming at good scalability and acceptable overhead, this paper intro- duces the concept of pessimism grain and presents a coarse-grained pessimistic message-logging scheme. The paper also evaluates the impact of pessimism grain on the performance of the recovery scheme. Ex- perimental results show that pessimism grain is one of the key configuration parameters to reach a desired performance level. In practice, the proper pessimism grain should be selected based on the characteristics of the applications.