The role of modelling in identifying drug targets for diseases of the cell cycle.

The cell cycle is implicated in diseases that are the leading cause of mortality and morbidity in the developed world. Until recently, the search for drug targets has focused on relatively small parts of the regulatory network under the assumption that key events can be controlled by targeting single pathways. This is valid provided the impact of couplings to the wider scale context of the network can be ignored. The resulting depth of study has revealed many new insights; however, these have been won at the expense of breadth and a proper understanding of the consequences of links between the different parts of the network. Since it is now becoming clear that these early assumptions may not hold and successful treatments are likely to employ drugs that simultaneously target a number of different sites in the regulatory network, it is timely to redress this imbalance. However, the substantial increase in complexity presents new challenges and necessitates parallel theoretical and experimental approaches. We review the current status of theoretical models for the cell cycle in light of these new challenges. Many of the existing approaches are not sufficiently comprehensive to simultaneously incorporate the required extent of couplings. Where more appropriate levels of complexity are incorporated, the models are difficult to link directly to currently available data. Further progress requires a better integration of experiment and theory. New kinds of data are required that are quantitative, have a higher temporal resolution and that allow simultaneous quantitative comparison of the concentration of larger numbers of different proteins. More comprehensive models are required and must accommodate not only substantial uncertainties in the structure and kinetic parameters of the networks, but also high levels of ignorance. The most recent results relating network complexity to robustness of the dynamics provide clues that suggest progress is possible.     

A physically based approach to granular media mechanics: grain-scale experiments,initial results and implications to numerical modeling

It is generally appreciated that the mechanical behavior of granular media depends fundamentally on the interaction of the constituent particles, and that the validity of numerical models of granular media would be greatly improved with knowledge of the grain-scale mechanics. However, most supporting experimental work has been conducted on highly idealized materials, and a limited amount of information exists on grain-scale force–displacement relationships for naturally occurring materials. To address this shortcoming, we are conducting a program that integrates laboratory experiments on grains of naturally occurring aggregate with the discrete element modeling method, with the goal of relating the grain-scale physical and mechanical properties of granular media to bulk behavior. The paper describes the equipment and methods that have been developed to conduct close-loop controlled, grain-scale experiments under monotonic and cyclic loading conditions, and presents results from an initial set of experiments on unbonded grains. The implications of the grain-scale results to the discrete element model are discussed. Discussions center on the applicability of a physically based approach to the mechanics of granular media in general. In light of future exploration missions and the resulting need to predict the mechanical properties of lunar and planetary regoliths, the paper examines the potential usefulness of our physically based approach to the problem of predicting the behavior of the types of materials found in those environments.     

Communication Law and Policy: The State of Research and Theory

This essay describes the domain of research in communication law and policy. It is based on a content analysis of research published in the journal Communication Law and Policy (1996–2004), papers presented to the Communication Law and Policy Division at annual conferences of the International Communication Association (1997–2004), as well as consideration of other resources. The most frequent areas for research were media regulation, Internet policy, and freedom of expression issues. After reviewing recent literature on the first two topics, we identified and showcased two emergent categories deserving future attention: communication and the law (particularly fair trial-free press issues) and implications of the burgeoning consolidation of media ownership.     

Master sintering curve concepts as applied to the sintering of molybdenum

Sintering experiments with various molybdenum powders are rationalized using a master sintering curve concept that collapses density, grain size, or other parameters onto a single curve. In this case, the integral work of sintering is developed and customized for different green densities. Construction of the master sintering curve is described to show how the curve can be normalized with respect to green density effects. Various grades of molybdenum for metal injection molding and die compaction are included in the analysis, processed over a range of heating cycles. Die-compacted samples of varying green densities are used to illustrate the efficacy of the new, normalized master sintering curve concept. Sintering cycle optimization is one possible outcome from this analysis.     

Improved quality of continuous flow manufacturing through the combination of statistical process control and conventional computer process control

This paper represents a portion of the evaluation of the use of Statistical Process Control within the realm of Conventional Computer Process Control. Various control charts commonly utilized in continuous processes are evaluated when subjected to process disturbances typical of continuous processes. The control charts considered are the Moving Average and Moving Range Chart combination, the Individual and Moving Range Chart combination, and the Exponentially Weighted moving Average Chart. The types of process disturbances considered are unit step and linear trend disturbances to the process average. The evaluation is based on the determination of the Average Run Lengths (ARLs) resulting from computer simulations.     

Biologically active secondary metabolites of barley. IV. Hordenine production by different barley lines

Forty-three lines of barley, including ancestral (wild), landraces, Middle Eastern lines, and modern cultivars, were grown under two different sets of environmental conditions. Hordenine production in barley roots was determined at the one-leaf stage by HPLC analysis and, in two lines only, over a period of 35 days. Forty-two of the 43 lines produced significant amounts of hordenine, although there was no variation among groups. Middle Eastern lines had the highest production with 327 µg/g on a dry weight basis. Production was, however, determined more by environmental conditions during growth than by genetic factors. Hordenine production was up to seven times higher in plants grown under lower light intensities.     

The effects of goal difficulty on physiological arousal, cognition, and task performance.

Conducted 2 laboratory experiments with 117 undergraduates to examine (1) the effect of assigned goal difficulty on arousal (self-report and heart rate), cognition (perceived norm, self-efficacy strength, and personal goal), and behavioral (task performance) measures and (2) the role of heart rate as a mediator of the goal-difficulty–performance relation. All Ss performed a task requiring cognitive and physical responses. Results of both experiments demonstrate that assigned goal difficulty affected heart rate, cognition, and task performance and that heart rate change was positively related to the cognitive and behavioral measures. Regression analyses suggested that a cognitive–affective mechanism may mediate the goal-difficulty–performance relation. Discussion is focused on the theoretical and practical implications of integrating an arousal concept within goal-setting theory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

3G及后3G时代

1 引言 目前,3G标准已制定完备,频谱也可用,牌照已授予,基础设施也准备就绪。当日本和英国等市场的首批运营商推出3G网络时,全世界都在期待着3G之后的新技术。亚洲在决定这一新领域的过程中起着领导作用。这是因为:首先,亚洲运营商获得3G许可证的成本相对较少,因此他们的资产负债表仍处于良好状态。其次,亚洲融合了不同标准,亚洲市场有很多竞争的3G技术,不