Status and Multiple Growth Regimes

In order to explain multiple growth regimes, one of the working hypotheses is based on initial conditions. Using a standard optimal growth with the status effect represented by wealth a la Friedman (1953), this paper obtains multiple growth regimes based on initial conditions without reliance on other assumptions such as nonlinearities of production or consumption functions and heterogeneous agents/savings behavior. With the status effect, the resulting equilibrium distribution is characterized by a group with a lower level of income and another group with a higher level of income. Globally, a sufficiently strong monetary policy may be an instrument in order for an economy in poverty traps to take off and become wealthy in the long run. Locally, our model sheds light on the relationship between money/inflation and capital in the long run that, given general cash-in-advance constraints on investment relative to consumption, is determined by the curvature of the utilities of wealth and consumption.one-sector growth model, wealth effect, CIA constraint, takeoff

Inflation and Growth: Impatience and a Qualitative Equivalence

This paper studies the role of an endogenous time preference on the relationship between inflation and growth in the long run in both the money-in-utility-function (MIUF) and transaction costs (TC) models. We establish a qualitative equivalence between the two models in a setup without a labor-leisure tradeoff. When the time preference is decreasing (or increasing) in consumption and real balances, both the MIUF and TC models are qualitatively equivalent in terms of predicting a negative (or positive) relationship between inflation and growth in a steady state. Both a decreasing and an increasing time preference in consumption are consistent with the arguments in the literature. While a decreasing time preference in real balances corroborates with empirical evidence, there is no evidence in support of an increasing time preference in real balances.endogenous time preferences, superneutrality, qualitative equivalence

Scheduling Issues in Real-Time Systems

The most important objective of real-time systems is to fulfill time-critical missions in satisfying their application requirements and timing constraints. Software utilities can analyze real-time tasks and extract their characteristics and requirements for assisting the systems to guarantee schedulability. Real- time scheduling is the core of the real-time system design. It should allow real-time systems to exhibit predictable timing correctness regardless of possible uncertainty in run-time environments. In this dissertation, we study the problem of scheduling real-time tasks with resource and fault-tolerance requirements. For tasks with resource requirements, two types of platforms are examined: multiprocessor hard real-time systems and real-time database systems; for task with fault-tolerance requirements, we focus on hard real-time systems. We investigate preemptive priority-based scheduling for tasks with resource requirements in context of hard real-time systems. Rate-monotonic and earliest deadline first priority assignment strategies can meet deadlines if the schedulability conditions are satisfied. We propose resource control protocols, for these scheduling strategies, based on the concepts of priority inheritance and priority ceiling and describe schedulability conditions for meeting deadlines. Real-time database systems have different objectives for transaction scheduling. Minimizing miss ratio usually is the major concern. We study the significance of the knowledge of execution time in system performance and propose a class of optimistic concurrency control protocols using the knowledge of execution time. Our simulation results indicate that the knowledge of execution time substantially improve system performance. Fault-tolerance is an ability to maintain system in a safe and stable state such that the real-time application functions correctly and its timing constraints are satisfied even in the presence of faults. We develop a scheduling algorithm which attempts to build as many fault-tolerant tasks as possible into a schedule. We approximate system reliability by Markov chain models and illustrate the applicability of the proposed reliability models. We compare the proposed fault-tolerance scheduling approach with the basic fault-tolerance scheduling schemes and the simulation results show that our method provides better reliability than the basic scheduling schemes. (Also cross-referenced as UMIACS-TR-95-73

Electrostatic Control and Chloride Regulation of the Fast Gating of ClC-0 Chloride Channels

The opening and closing of chloride (Cl−) channels in the ClC family are thought to tightly couple to ion permeation through the channel pore. In the prototype channel of the family, the ClC-0 channel from the Torpedo electric organ, the opening-closing of the pore in the millisecond time range known as “fast gating” is regulated by both external and internal Cl− ions. Although the external Cl− effect on the fast-gate opening has been extensively studied at a quantitative level, the internal Cl− regulation remains to be characterized. In this study, we examine the internal Cl− effects and the electrostatic controls of the fast-gating mechanism. While having little effect on the opening rate, raising [Cl−]i reduces the closing rate (or increases the open time) of the fast gate, with an apparent affinity of >1 M, a value very different from the one observed in the external Cl− regulation on the opening rate. Mutating charged residues in the pore also changes the fast-gating properties—the effects are more prominent on the closing rate than on the opening rate, a phenomenon similar to the effect of [Cl−]i on the fast gating. Thus, the alteration of fast-gate closing by charge mutations may come from a combination of two effects: a direct electrostatic interaction between the manipulated charge and the negatively charged glutamate gate and a repulsive force on the gate mediated by the permeant ion. Likewise, the regulations of internal Cl− on the fast gating may also be due to the competition of Cl− with the glutamate gate as well as the overall more negative potential brought to the pore by the binding of Cl−. In contrast, the opening rate of the fast gate is only minimally affected by manipulations of [Cl−]i and charges in the inner pore region. The very different nature of external and internal Cl− regulations on the fast gating thus may suggest that the opening and the closing of the fast gate are not microscopically reversible processes, but form a nonequilibrium cycle in the ClC-0 fast-gating mechanism

Designing and Evaluating an Automatic Forensic Model for Fast Response of Cross-Border E-Commerce Security Incidents

[[abstract]]The rapid development of cross-border e-commerce over the past decade has accelerated the integration of the global economy. At the same time, cross-border e-commerce has increased the prevalence of cybercrime, and the future success of e-commerce depends on enhanced online privacy and security. However, investigating security incidents is time- and cost-intensive as identifying telltale anomalies and the source of attacks requires the use of multiple forensic tools and technologies and security domain knowledge. Prompt responses to cyber-attacks are important to reduce damage and loss and to improve the security of cross-border e-commerce. This article proposes a digital forensic model for first incident responders to identify suspicious system behaviors. A prototype system is developed and evaluated by incident response handlers. The model and system are proven to help reduce time and effort in investigating cyberattacks. The proposed model is expected to enhance security incident handling efficiency for cross-border e-commerce.[[notice]]補正完

Communication-efficient three-party protocols for authentication and key agreement

AbstractEncrypted key exchange (EKE) authentication approaches are very important for secure communicating over public networks. In order to solve the security weaknesses three-party EKE, Yeh et al. [H.T. Yeh, H.M. Sun, T. Hwang, Efficient three-party authentication and key agreement protocols resistant to password guessing attacks, Information Science and Engineering 19 (6) (2003) 1059–1070.] proposed two secure and efficient three-party EKE protocols. Based on the protocol developed by Yeh et al., two improved EKE protocols for authentication and key agreement are proposed in this study. The computational costs of the proposed protocols are the same as those of the protocols of Yeh et al. However, the numbers of messages in the communication are fewer than those of the protocols of Yeh et al. Furthermore, the round efficient versions of our proposed protocols are also described

Multiprocessor Priority Ceiling Based Protocols

We study resource synchronization in multiprocessor hard real-time systems. Specifically, we propose a multiprocessor resource control protocol which allows a job to simultaneously lock multiple global resources, removing a restriction from previous protocols. Allowing nested critical sections may permit a finer granularity of synchronization, increasing parallelism and throughput. All the protocols discussed belong to the class of priority inheritance protocols and rely in some fashion on priority ceilings for global semaphores. We consider both static and dynamic priorities, building upon the multiprocessor priority ceiling protocol (MPCP) proposed by Rajkumar et al. and the dynamic priority ceiling protocol (DPCP) proposed by Chen and Lin. The extended protocols prevent deadlock and transitive blocking. We derive bounds for worse case blocking time, and describe sufficient conditions to guarantee that m sets of periodic tasks can be scheduled on an rn multiprocessor system. Performance comparisons of these protocols with MPCP shows that the proposed protocols increase schedulability. (Also cross-referenced as UMIACS-TR-94-42

Patrones individuales de dispersión de larvas de góbidos en un estudiaro indicados por la composición elemental de los otolitos

Otolith trace elements were used as natural tags to study the dispersal patterns of goby larvae in an estuary. Ninety-six larval gobies representing 10 species were collected in the estuary of Gongshytyan Creek in northwestern Taiwan in September 1997. Fifteen trace elements in fish otoliths were analysed with solution-based ICPMS. Trace elemental composition in otoliths differed significantly among the species. Habitat use by the larvae of the 10 species can be divided into four groups, based on principal component analysis of otolith elemental composition. All 10 goby species used the estuary as a nursery area irrespective of the fish being amphidromous or non-amphidromous. A part of the population may be lost during larval dispersal, as indicated from trace elemental composition recorded in the otolith.Se utilizó la composición elemental en los otolitos de larvas de góbidos como trazadores naturales para estudiar los patrones de dispersión en un estuario. Durante septiembre de 1997 se recolectaron 96 larvas de góbidos pertenecientes a 10 especies distintas en el estuario de Gongshytyan Creek situado en el noroeste de Taiwan . Se analizaron 15 elementos traza mediante espectroscopia de masas (ICPMS). La composición de elementos traza en los otolitos difirió significativamente entre especies. En base al Análisis de Componentes Principales de la composición elemental de los otolitos, los hábitats utilizados por las 10 especies pudieron dividirse en 4 grupos. Las 10 especies de góbidos usan el estuario como área de cría, independientemente de que las especies sean anfidromas o no-anfidromas. La composición elemental determinada para los otolitos analizados, permitió comprobar que una parte de la población puede ser perdida durante la dispersión larvaria

Akt Determines Replicative Senescence and Oxidative or Oncogenic Premature Senescence and Sensitizes Cells to Oxidative Apoptosis

SummaryAkt deficiency causes resistance to replicative senescence, to oxidative stress- and oncogenic Ras-induced premature senescence, and to reactive oxygen species (ROS)-mediated apoptosis. Akt activation induces premature senescence and sensitizes cells to ROS-mediated apoptosis by increasing intracellular ROS through increased oxygen consumption and by inhibiting the expression of ROS scavengers downstream of FoxO, particularly sestrin 3. This uncovers an Achilles' heel of Akt, since in contrast to its ability to inhibit apoptosis induced by multiple apoptotic stimuli, Akt could not inhibit ROS-mediated apoptosis. Furthermore, treatment with rapamycin that led to further Akt activation and resistance to etoposide hypersensitized cancer cells to ROS-mediated apoptosis. Given that rapamycin alone is mainly cytostatic, this constitutes a strategy for cancer therapy that selectively eradicates cancer cells via Akt activation