Xanthohumol for Human Malignancies: Chemistry,Pharmacokinetics and Molecular Targets

Xanthohumol (XH) is an important prenylated flavonoid that is found within the inflorescence of Humulus lupulus L. (Hop plant). XH is an important ingredient in beer and is considered a significant bioactive agent due to its diverse medicinal applications, which include anti-inflammatory, antimicrobial, antioxidant, immunomodulatory, antiviral, antifungal, antigenotoxic, antiangiogenic, and antimalarial effects as well as strong anticancer activity towards various types of cancer cells. XH acts as a wide ranging chemopreventive and anticancer agent, and its isomer, 8-prenylnaringenin, is a phytoestrogen with strong estrogenic activity. The present review focuses on the bioactivity of XH on various types of cancers and its pharmacokinetics. In this paper, we first highlight, in brief, the history and use of hops and then the chemistry and structure–activity relationship of XH. Lastly, we focus on its prominent effects and mechanisms of action on various cancers and its possible use in cancer prevention and treatment. Considering the limited number of available reviews on this subject, our goal is to provide a complete and detailed understanding of the anticancer effects of XH against different cancers.     

IBM's Linux watch, the challenge of miniaturization

Nearly four years in development, the IBM Linux watch contains a complete computer system that runs Linux, displays X11 graphics, and has wireless connectivity. The system fits in a case that could pass as a slightly unusual analog timepiece with a somewhat odd shape and an extraordinarily brilliant face. The developers have created two versions of the watch, one with an organic light-emitting diode display and the other with a liquid crystal display. Still considered a research prototype, the watch already runs some personal information management applications, and it can communicate with PCs, PDAs, and other wireless-enabled devices, viewing condensed e-mail and directly receiving pager-like messages. Eventually, users will be able to access various Internet-based services, such as up-to-the-minute information about weather, traffic conditions, the stock market, and sports     

Finite data performance analysis of MVDR beamformer with andwithout spatial smoothing

The finite-data performance of a minimum-variance distortionless response (MVDR) beamformer is analyzed with and without spatial smoothing, using first-order perturbation theory. In particular, expressions are developed for the mean values of the power gain in any direction of interest, the output power, and the norm of the weight-error vector, as a function of the number of snapshots and the number of smoothing steps. It is shown that, in general, the smoothing, in addition to decorrelating the sources, can alleviate the effects of finite-data perturbations. The above expressions are reduced to the case in which no spatial smoothing is used. These expressions are valid for an arbitrary array and for arbitrarily correlated signals. For this case, an expression for the variance of the power gain is also developed. For a single interference case it is shown explicitly how the SNR, spacing of the interference from the desired signal and the correlation between them influence the beamformer performance. Simulations verify the usefulness of the theoretical expressions     

Real-time payments for mobile IP

The mobile IP protocol has evolved from providing mobility support for portable computers to support for wireless handheld devices with high mobility patterns. A new category of micromobility protocols has been proposed to deal with the increased signaling loads that will be generated with large populations of such devices on a network. We argue that the authentication schemes presently employed in these networks do not scale well for large numbers of nodes, and that the lack of accounting procedures prevents the mass deployment of these networks. We envisage that future access networks will be operated by independent service providers, who will charge users for access to services in the fixed network but may not have long-term contractual relationships with them. These access networks may also employ a variety of micromobility protocols for fast handover support. We present a scheme based on hash chains, which allows for fast authentication of datagrams for secure updating of router entries within the access network, and real-time accounting of network usage by mobile nodes. Such a system will alleviate problems of fraud in mobile networks and eliminate the need for interoperator billing agreements.     

Precipitation hardening in nickel-copper base alloy monel K 500

The occurrence of a significant amount of age hardening, due to the precipitation of the γ′ phase, has been demonstrated in the nickel-copper base alloy MONEL K 500. The microstructure of the precipitation-hardened and deformed alloy has been examined in peak-aged underaged and overaged conditions. An attempt has been made to compare the observed increments in strength in these three aged conditions to those predicted on the basis of relevant theoretical models.     

Regeneration with virtual copies for distributed computing systems

The authors consider the consistency control problem for replicated data in a distributed computing system (DCS) and propose a new algorithm to dynamically regenerate copies of data objects in response to node failures and network partitioning in the system. The DCS is assumed to have strict consistency constraints for data object copies. The algorithm combines the advantages of voting-based algorithms and regeneration mechanisms to maintain mutual consistency of replicated data objects in the case of node failures and network partitioning. The algorithm extends the feasibility of regeneration to DCS on wide area networks and is able to satisfy user queries as long as there is one current partition in the system. A stochastic availability analysis of the algorithm shows that it provides improved availability as compared to previously proposed dynamic voting algorithms