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Transfer Protocol (transfer + protocol)
Selected AbstractsAdvanced IMS client supporting secure signalingBELL LABS TECHNICAL JOURNAL, Issue 4 2008Ramana Isukapalli With recent advances in core and access networks and the availability of increased bandwidth and sophisticated devices for end users, there is an increased demand for client applications running on mobile devices, such as laptops and handheld devices, to support real time applications like Voice over Internet Protocol (VoIP) and streaming video, apart from traditional applications like web browsing. This paper presents a prototype IP Multimedia Subsystem (IMS) client, which serves as a VoIP client to set up calls between Internet Protocol (IP) devices and interworks with circuit-switched networks to deliver calls to public switched telephone network (PSTN) phones. It implements supplementary services (including call waiting, call transfer, and call forwarding); supports multimedia ringing, short message service/multimedia messaging service (SMS/MMS), audio/video conferencing, and peer-to-peer video; and it can deliver a call to a user (as opposed to a device) by simultaneously ringing multiple devices registered by the user. Further, to address various security concerns, the client supports Hypertext Transfer Protocol (HTTP) digest authentication using Message Digest 5 (MD5) cryptographic function authentication and key agreement (AKA) and can create secure tunnels to the core network using IP security (IPsec). © 2008 Alcatel-Lucent. [source] Secure parallel file distribution through a streaming worm networkBELL LABS TECHNICAL JOURNAL, Issue 1 2007Michael J. Sheehan This paper introduces the novel concept of streaming worms and applies the concept to secure parallel file transfer. A streaming worm (sworm) is a powerful class of software that can replicate itself as well as a chunk of arbitrary payload code on a predetermined set of nodes in a network very quickly, while streaming data between all of the nodes in parallel. By harnessing the parallelism and scalability of sworms in a file distribution application, large gigabyte files can be efficiently and securely distributed to a large number of nodes over a Transmission Control Protocol/Internet Protocol (TCP/IP) network without congesting the network. But unlike traditional file transfer tools such as File Transfer Protocol (FTP), remote copy (RCP), or secure copy (SCP), the total sworm transfer time is relatively independent of the number of target nodes for large files. As such, this method of parallel file distribution is particularly useful when a large array or cluster of similar computers has to be quickly updated with a large amount of identical software or data. © 2007 Alcatel-Lucent. [source] Hybrid Light-Emitting Diodes from Microcontact-Printing Double-Transfer of Colloidal Semiconductor CdSe/ZnS Quantum Dots onto Organic Layers,ADVANCED MATERIALS, Issue 10 2008Aurora Rizzo A novel dry deposition approach is developed to transfer arrays of colloidal quantum dots onto organic thin films, as illustrated in the figure. A red light-emitting device combining inorganic and organic components is fabricated based on this simple transfer protocol. [source] Experience with Delay-Tolerant Networking from orbit,INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 5-6 2010W. Ivancic Abstract We describe the first use from space of the Bundle Protocol for Delay-Tolerant Networking (DTN) and lessons learned from experiments made and experience gained with this protocol. The Disaster Monitoring Constellation (DMC), constructed by Surrey Satellite Technology Ltd (SSTL), is a multiple-satellite Earth-imaging low-Earth-orbit sensor network in which recorded image swaths are stored onboard each satellite and later downloaded from the satellite payloads to a ground station. Store-and-forward of images with capture and later download gives each satellite the characteristics of a node in a disruption-tolerant network. Originally developed for the ,Interplanetary Internet,' DTNs are now under investigation in an Internet Research Task Force (IRTF) DTN research group (RG), which has developed a ,bundle' architecture and protocol. The DMC is technically advanced in its adoption of the Internet Protocol (IP) for its imaging payloads and for satellite command and control, based around reuse of commercial networking and link protocols. These satellites' use of IP has enabled earlier experiments with the Cisco router in Low Earth Orbit (CLEO) onboard the constellation's UK-DMC satellite. Earth images are downloaded from the satellites using a custom IP-based high-speed transfer protocol developed by SSTL, Saratoga, which tolerates unusual link environments. Saratoga has been documented in the Internet Engineering Task Force (IETF) for wider adoption. We experiment with the use of DTNRG bundle concepts onboard the UK-DMC satellite, by examining how Saratoga can be used as a DTN ,convergence layer' to carry the DTNRG Bundle Protocol, so that sensor images can be delivered to ground stations and beyond as bundles. Our practical experience with the first successful use of the DTNRG Bundle Protocol in a space environment gives us insights into the design of the Bundle Protocol and enables us to identify issues that must be addressed before wider deployment of the Bundle Protocol. Published in 2010 by John Wiley & Sons, Ltd. [source] Single-dose lentiviral gene transfer for lifetime airway gene expressionTHE JOURNAL OF GENE MEDICINE, Issue 10 2009Alice G. Stocker Abstract Background Cystic fibrosis (CF) is caused by a defect in cystic fibrosis transmembrane conductance regulator (CFTR) activity, often resulting in an incurable airway disease. Gene therapy into the conducting airway epithelium is a potential cure for CF; however, most gene vectors do not result in long-lived expression, and require re-dosing. Perversely, intrinsic host immune responses can then block renewed gene transfer. Methods To investigate whether persistent gene expression could be achieved after a single dosing event, thus avoiding the issue of blocking host responses, we used a gene transfer protocol that combined an airway pretreatment using lysophosphatidylcholine with a human immunodeficiency virus type-1 (vesicular stomatitis virus G pseudotype) derived lentiviral vector to test whether an integrating vector could produce gene expression able to last for a substantial part of the lifetime of the laboratory mouse. Results We found that a single dose of LV-LacZ produced immediate as well as lifetime mouse airway expression, confirming our hypothesis that use of an integrating vector extends transgene expression. Importantly, LV-CFTR dosing achieved at least 12 months of CFTR expression, representing partial functional correction of the CFTR defect in CF-null mice. Conclusions These findings validate the potential of this methodology for developing a gene transfer treatment for CF airway disease. Copyright © 2009 John Wiley & Sons, Ltd. [source] User-level QoS and traffic engineering for 3G wireless 1xEV-DO systemsBELL LABS TECHNICAL JOURNAL, Issue 2 2003Simon C. Borst Third-generation (3G) wireless systems such as 3G1X, 1xEV-DO, and 1xEV-DV provide support for a variety of high-speed data applications. The success of these services critically relies on the capability to ensure an adequate quality of service (QoS) experience to users at an affordable price. With wireless bandwidth at a premium, traffic engineering and network planning play a vital role in addressing these challenges. We present models and techniques that we have developed for quantifying the QoS perception of 1xEV-DO users generating file transfer protocol (FTP) or Web browsing sessions. We show how user-level QoS measures may be evaluated by means of a Processor-Sharing model that explicitly accounts for the throughput gains from multi-user scheduling. The model provides simple analytical formulas for key performance metrics such as response times, blocking probabilities, and throughput. Analytical models are especially useful for network deployment and in-service tuning purposes due to the intrinsic difficulties associated with simulation-based optimization approaches. © 2003 Lucent Technologies Inc. [source] Biodistribution of the RD114/mammalian type D retrovirus receptor, RDRTHE JOURNAL OF GENE MEDICINE, Issue 3 2004Bronwyn J. Green Abstract Background The limited expression of viral receptors on target cells is a recognized barrier to therapeutic gene transfer. Previous analysis of receptor expression has been performed using indirect methods due to a lack of receptor-specific antibodies. Methods In this report we have used anti-RDR antiserum to provide direct histochemical and flow cytometric analysis of the expression of RDR, which is the cognate receptor for RD114-pseudotyped vectors as well as being a neutral amino acid transporter. Results RDR was present on a range of normal tissues with relevance to gene therapy including: colon, testis, ovary, bone marrow and skeletal muscle. It was also highly expressed on immature cells present in the squamous epithelia of skin, cervix, nasal mucosa, bronchus and tonsil. Of relevance to possible germline gene transfer, we demonstrated a lack of RDR expression on male or female germ cells. RDR expression on mature hemopoietic cell subsets showed up to 5-fold variability between individuals within each lineage,with some individuals expressing low levels of RDR across all blood lineages. Both myeloid and monocytic lineages contained the highest fraction of cells expressing RDR, whereas lymphoid lineages showed the lowest. Coexpression of CD34 and RDR ranged from 2.04 to 0.44% in G-CSF-mobilized peripheral blood samples. Conclusions As a means to optimize gene transfer protocols, biodistribution studies such as these are fundamental to enable targeting of the virus receptor most abundantly expressed on relevant populations. The inter-individual variation of receptor expression seen here also raises the possible requirement for tailor-made gene therapy protocols. Copyright © 2004 John Wiley & Sons, Ltd. [source] Mathematical model of the rate-limiting steps for retrovirus-mediated gene transfer into mammalian cellsBIOTECHNOLOGY & BIOENGINEERING, Issue 1 2010Venkata S. Tayi Abstract A quantitative understanding of the process of retrovirus-mediated gene transfer into mammalian cells should assist the design and optimization of transduction protocols. We present a mathematical model of the process that incorporates the essential rate-limiting transduction steps including diffusion, convection and decay of viral vectors, their binding at the cell surface and entry into the cell cytoplasm, reverse transcription of uncoated RNA to form DNA intermediates, transport of the latter through the cytosol to the cell nucleus and, finally, nuclear import and integration of the delivered DNA into the target cell genome. Cell and virus population balances are used to account for the kinetics of multiple vector infections which influence the transduction efficiency and govern the integrated copy number. The mathematical model is validated using gibbon ape leukemia virus envelope pseudotyped retroviral vectors and K562 target cells. Viral intermediate complexes derived from the internalized retroviral vectors are found to remain stable inside the K562 cells and the cytoplasmic trafficking time is consistent with the time scale for retrovirus uncoating, reverse transcription and transport to the cell nucleus. The model predictions of transduction efficiency and integrated copy number agree well with experimental data for both static (i.e., standard gravity) and centrifugation-based gene transfer protocols. The formulation of the model can also be applied to transduction protocols involving lenti- or foamy-viruses and so should prove to be useful for the optimization of several types of gene transfer processes. Biotechnol. Bioeng. 2010;105: 195,209. © 2009 Wiley Periodicals, Inc. [source] Bed rest versus free mobilisation following embryo transfer: a prospective randomised studyBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 11 2004Zouhair O. Amarin Objective To evaluate the efficacy of two clinical methods of post-embryo transfer protocols in patients undergoing in vitro fertilisation. Design Prospective, randomised clinical trial. Setting Hospital-based clinic for reproductive medicine. Sample Women under 40 years of age who were undergoing in vitro fertilisation with GnRH pituitary down-regulation and controlled ovarian hyperstimulation. Methods Patients were randomised to rest for either 1 or 24 hours after embryo transfer. Main outcome measure Clinical pregnancy per cycle rate (the percentage of cycles started that demonstrated a live fetus on ultrasound examination performed at six or seven weeks of gestation). Results The clinical pregnancy rates were 21.5% for the 1-hour and 18.2% for the 24-hour post-embryo transfer groups. The implantation rate per embryo was significantly higher in the 1-hour group (14.4%) than in the 24-hour group (9%). Conclusion One-hour and 24-hour rest post-embryo transfer result in comparable rates of clinical pregnancy. However, 24-hour rest results in reduced implantation rate per embryo. [source] Utilization of catheterization and revascularization procedures in patients with non-ST segment elevation acute coronary syndrome over the last decadeCATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 2 2005Glenn N. Levine MD Abstract The degree to which catheterization and revascularization procedures are utilized in patients with non-ST segment elevation acute coronary syndrome (NSTE-ACS) during hospitalization has broad implications with respect to initial pharmacotherapeutic decisions (upfront therapies), treatment and hospital transfer protocols, guideline recommendations, and allocation of training, material, and financial resources. Analysis of data from multiple trials and registries of patients with NSTE-ACS has the potential to assess more broadly utilization of invasive and revascularization procedures and provide a wide angle or bird's-eye view of the management of such patients, complementing the data obtained from any one trial or registry. We therefore undertook a systematic overview of all large trials and registries of patients with NSTE-ACS conducted over the last decade that were deemed appropriate to provide information on catheterization and revascularization procedures. Although not unexpectedly the percentage of patients with NSTE-ACS managed with cardiac catheterization, percutaneous coronary intervention (PCI), and coronary artery bypass grafting varies in different clinical trials and registries, general findings and trends were still discernable from these studies. During the initial treatment period, the majority of patients were ultimately treated with medical therapy alone (e.g., without revascularization). The percentage of those NSTE-ACS patients undergoing diagnostic cardiac catheterization who were then managed with PCI increased over the last decade and now stands at approximately 50%. Of NSTE-ACS patients who undergo revascularization, the percentage of those patients who are revascularized via PCI similarly increased, and PCI is currently the revascularization procedure utilized in approximately three-fourths of patients undergoing revascularization. The percentages of patients undergoing invasive and revascularization procedures were consistently higher in the U.S. cohorts of study subjects when compared to non-U.S. cohorts of study subjects. © 2005 Wiley-Liss, Inc. [source] | |||||||||||||