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Picornaviruses have a peptide termed VPg covalently linked to the 5'-end of the genome. Attachment of VPg to the genome occurs in at least two steps. First, Tyr-3 of VPg, or some precursor thereof, is used as a primer by the viral RNA-dependent RNA polymerase, 3Dpol, to produce VPg-pUpU. Second, VPg-pUpU is used as a primer to produce full-length genomic RNA. Production of VPg-pUpU is templated by a single adenylate residue located in the loop of an RNA stem-loop structure termed oriI by using a slide-back mechanism. Recruitment of 3Dpol to and its stability on oriI have been suggested to require an interaction between the back of the thumb subdomain of 3Dpol and an undefined region of the 3C domain of viral protein 3CD. We have performed surface acidic-to-alanine-scanning mutagenesis of 3C to identify the surface of 3C with which 3Dpol interacts. This analysis identified numerous viable poliovirus mutants with reduced growth kinetics that correlated to reduced kinetics of RNA synthesis that was attributable to a change in VPg-pUpU production. Importantly, these 3C derivatives were all capable of binding to oriI as well as wild-type 3C. Synthetic lethality was observed for these mutants when placed in the context of a poliovirus mutant containing 3Dpol-R455A, a residue on the back of the thumb required for VPg uridylylation. These data were used to guide molecular docking of the structures for a poliovirus 3C dimer and 3Dpol, leading to a structural model for the 3C(2)-3Dpol complex that extrapolates well to all picornaviruses.

In this paper, we apply the method of Granger causality which is more accurate than classical correlation analysis method to determine whether the main air pollutants — Nitrogen oxides (NO x ), SO 2 (Sulfur Dioxide), CO (carbon monoxide), TSP (total suspended particulates), PM 10 (particulate matter smaller than 10 microns) and the mortality of respiratory diseases of the residents in Beijing have causal relationship. After ensuring NO x , SO 2 and CO as the responsible substances, we use the time series method to construct the autoregressive integrated moving average model (ARIMA) of the pollutants, so that we could predict the amount of the pollutants from 2005 to 2008. Then we use the predicted value of pollutants as the input of the neural network model and obtain the output as the change of the death rate of respiratory diseases from 2005 to 2008. In the end, reducing the amount of pollutants by 10% and inputting the data in the neural network model, we make the prediction to evaluate the level of the pollutants and concluded that NO x is the most important pollutant to control.

Advances in networking, sensors, and embedded devices have made it feasible to monitor and provide medical and other assistance to people in their homes. Aging populations will benefit from reduced costs and improved healthcare through assisted living based on these technologies. However, these systems challenge current state-of-the-art techniques for usability, reliability, and security. In this paper we present the PAS open architecture for assisted living, which allows independently developed third party components to collaborate. We discuss key technological issues in assisted living systems, such as tracking, fall detection, security and privacy; and results from our pilot study in a real assisted living facility are presented.

We address two necessary issues needed for developing safe and reliable MD PnP systems: robust wireless networking and automated checking for component interoperability and reliability. First, the robustness of a wireless network can be improved by the use of DSSS-CDMA, which tradeoff throughput to achieve higher reliability and persistence of connections as needed. Second, automated checking of components interoperability and reliability can be partially addressed by the use of the integrated framework for assumptions and dependencies (IFAD) by specifying a machine-checkable encoding of component information, checking interface assumptions, and finding how various environmental changes can impact the system.

HIV/ADIS will be one of the greatest challenges in public health in this century. As the burst increased rate of AIDS patients, governments and organizations are investing unprecedented resources in AIDS prevention and therapy. The following contents constitute the work that we done in this paper, and they can meet the requirement of all the tasks. To begin with, we define an index named risk index (Rl) to quantify the risk degree of each country that is threatened by HIV. Then we select six countries that have the largest Rl in the continent where they are located. The countries we select are South Africa, India, France, USA, Australia and Brazil. After we select the countries, we use a revised SIR model to estimate the rate of change of the number of HIV infections in the six countries and realize it on Matlab. Then we design a method to predict the expected global investment on HIV/AIDS from 2006 to 2050 for the six countries from foreign aid donors from 2006 to 2050. Besides, we define an index named safety index (SI) and use the method of linear programming to estimate the optimized amount of money allocated on drugs and vaccine on Lindo when the SI is the largest. After that, we re-estimate the rate of change of the number of HIV infections in the six countries under the three scenarios using three revised SIR models separately. In the end, we write a white paper of recommendations to the United Nations according to our analysis of the issue. Keywords-AIDS, SIR model, linear programming.

HIV/AIDS will be one of the greatest challenges in public health in this century. Nowadays the treatment and prevention of AIDS have become one of the most important research areas in the life science. Although there are many ways of therapy available, the therapeutic effects are not definitive. Thus, to achieve individual therapy of AIDS, the evaluation of these therapies becomes necessary. In this passage, using the data of ACTG320 group, we applied grey system theory to construct GM (1, 1) model. Taking into account of both the level of CD4 cells and HIV viral load, we defined K ( i,t ) as the curative effect index and evaluating the treatment. By running the program in Matlab, we estimate the best time frame to withdrawal the drugs for each patient and conclude that for most patients, the best time frame of withdrawal or change to use other drugs is from 20 to 40 weeks after the administration of the drug. Then we analyzed the data of 193A group to evaluate the therapeutic effect of the 4 groups of patients. We divided the patients into two groups: one is the young groups, the other is the old group, and the criterion is 50 year's old. We did this to reduce the affect of age on the therapeutic effect. In each age group, we used the treatment time and the dosage of drugs of four group patients as training sample input the neural network model to standardize the level of CD4 cells after treatment to evaluate the therapy methods in 193A. To remove the random errors which the neural network model brings into the process of solving, we predict the curative effect of the best therapy of each age group using time series model and run a program in SAS. To better apply our analysis into practice, we modify our goal programming model by Lingo software considering the price of the drugs. We concluded that compare with the therapy of reduce the type of drugs, reducing the dose is the better choice for the young patients when they are not in a good economic condition.

Advances in networking, sensors, and embedded devices have made it feasible to monitor and provide medical and other assistance to people in their homes. Aging populations will benefit from reduced costs and improved healthcare through assisted living based on these technologies. However, these systems challenge current state-of-the-art techniques for usability, reliability, and security. This is a particular challenge for open and extensible systems that combine software and hardware from many vendors and provide information to diverse clinicians. In this paper we present the I-Living architecture for assisted living that allows independent parties work together in a dependable, secure, and low-cost fashion with predictable properties. Our approach is based on an Assisted Living Service Provider (ALSP) who provides a server that collects and maintains encrypted assisted persons (APs)' records. Our ALSP can be a third party distinct from APs, communication providers, and clinicians; or it can be part of an ISP, hospital or similar enterprise. We have explored the architecture by developing a collection of applications and implementing them in a prototype system. Our system shows the feasibility and opportunity of an open approach to assisted living systems.

How to effectively allocate system resource to meet the service level agreement (SLA) of Web servers is a challenging problem. In this paper, we propose an improved scheme for autonomous timing performance control in Web servers under highly dynamic traffic loads. We devise a novel delay regulation technique called queue length model based feedback control utilizing server internal state information to reduce response time variance in presence of bursty traffic. Both simulation and experimental studies using synthesized workloads and real-world Web traces demonstrate the effectiveness of the proposed approach

How to allocate computing and communication resources in a way that maximizes the effectiveness of control and signal processing has been an important area of research. The characteristic of a multi-hop real-time wireless sensor network raises new challenges. First, the constraints are more complicated and a new solution method is needed. Second, we need a distributed solution to achieve scalability. This paper presents solutions to both of the new challenges. The first solution to the optimal frequency allocation is a centralized solution that can handle the more general form of constraints as compared with prior research. The second solution is a distributed version for large networks using a pricing scheme. It is capable of incremental adjustment when utility functions change.

To investigate the variations of HCV core and E2 region epitopes during transfusion of activated immune cells.Four patients receiving transfusion of activated immune cells were under continuously observation. HCV titers were measured by quantitive PCR. HCV core and E2 regions were cloned and sequences were analyzed by computer software.During the follow-up the serum ALT levels and the HCV virus titers fluctuated greatly in each of these persons. After transfusion, no significant variations were observed in HCV core and E2 coding regions.The alteration of host immune attacks could induce the fluctuations of HCV load without any mutations in the currently observed coding genes of the epitopes.

With the advancement of MEMS technologies, wireless networks consist of tiny sensor devices hold the promise of revolutionizing sensing in a wide range of application domains because of their flexibility, low cost and ease of deployment. However, the constrained computation power, battery power, storage capacity and communication bandwidth of the tiny devices pose challenging problems in the design and deployment of such systems. Target localization using acoustic signal with tiny wireless devices is a particularly difficult task due to the amount of signal processing and computation involved. In this paper, we provide an in-depth study of designing such wireless sensor networks for real-world acoustic tracking applications. We layout a cluster-based architecture to address the limitations of the tiny sensing devices. To achieve effective utilization of the scarce wireless bandwidth, a quality-driven paradigm to suppress redundant information and resolve contention is proposed. One instance of the quality-driven approach is implemented in the acoustic tracking system, where the quality of the tracking reports can be quantified numerically. We demonstrate the effectiveness of our proposed architecture and protocols using a sensor network testbed based on UCBerkeley mica motes. Considering the performance limitations of tiny sensor devices, the achieved acoustic target tracking accuracy is extraordinarily good. Our experimental study also shows that the acoustic target tracking quality can be indeed measured and used to assist resource allocation decisions. This application-driven design and implementation exercises also serve to identify important areas of further work in in-network processing and communications.

Objective. Current focusing and steering are both widely used to shape the electric field and increase the number of distinct perceptual channels in neural stimulation, yet neither technique has been used for an optic nerve (ON)-based visual prosthesis. In order to evaluate the effects of current focusing and steering in penetrative stimulation, we built an integrated computational model to simulate and investigate the influence of stimulating parameters on ON fibre recruitment. Approach. Finite element models with extremely fine meshes were first established to compute the 3D electric potential distribution under different stimulating parameters. Then the external electric potential was fed to randomized multi-compartment cable models to predict the distribution of fibres generating an action potential. Finally a statistical process was conducted to quantify the recruitment region. Main results. The simulation results show that a two-electrode mode is superior to a three-electrode mode in current steering. The three-electrode mode performs poorly in current focusing, albeit the localized recruitment from both configurations implies that current focusing might be unnecessary in penetrative ON stimulation. Significance. This study provides useful information for the optimized design of penetrating ON electrodes and stimulating strategies. The Monte Carlo style computation paradigm is designed to simulate neural responses of an ensemble of ON fibres, which can be immediately transferred to other similar problems.

Background This study aimed to evaluate the predictive values of hepatitis B e antigen (HBeAg) and hepatitis B surface antigen (HBsAg) levels in 171 Chinese patients with chronic hepatitis B who received a 48-week course of pegylated interferon alfa-2b therapy at 1.5 mcg/kg. Methods HBsAg, HBeAg, and hepatitis B virus (HBV) DNA levels were measured at baseline and weeks 12, 24, 48, and 72. Clinical responses were defined as a combined response (CR, HBeAg seroconversion [sustained response, SR] combined with HBV DNA level 1.5 logIU/mL at week 12 had a 54.5 % chance. Patients with HBsAg >20,000 IU/mL at weeks 12 and 24 had a 93.8 and 100.0 % chance, respectively, of not achieving a CR. An HBsAg level or changes at weeks 12 and 24, combined with HBeAg or HBV DNA, increased the chance for a SR and CR. Conclusions On-treatment HBsAg quantification, alone or in combination with HBeAg or HBV DNA, predicted off-treatment SR and CR after 48 weeks of PEG-IFNα-2b therapy, and thus, may guide clinicians in making a therapeutic decision to continue or terminate the therapy.

Acoustic awareness is an important service in ubiquitous computing environments. This paper presents a fast lightweight acoustic event localization protocol, the Lightning protocol, to locate impulsive sound sources using arrays of wireless micro-sensors. This protocol utilizes domain-invariant knowledge of acoustic and electromagnetic wave propagation to efficiently reduce the number of contending sensors in the localization process. It incurs O(1) transmissions irrespective of the sensor density and guarantees O(1) time delay in localization. Experiment results using UC Berkeley Motes demonstrate that the time delay for Lightning Protocol to locate hand clap sounds is in terms of milliseconds.