Studies have indicated the role of HSF1 (heat-shock transcription factor 1) in repressing the transcription of some nonheat shock genes. XAF1 (XIAP-associated factor 1) was an inhibitor of apoptosis-interacting protein with the effect of antagonizing the cytoprotective role of XIAP. XAF1 expression was lower in gastrointestinal cancers than in normal tissues with the mechanism unclear. Here we showed that gastrointestinal cancer tissues expressed higher levels of HSF1 than matched normal tissues. The expression of XAF1 and HSF1 was negatively correlated in gastrointestinal cancer cell lines. Stress stimuli, including heat, hypo-osmolarity, and H 2 O 2 , significantly suppressed the expression of XAF1, whereas the alteration of HSF1 expression negatively correlated with XAF1 expression. We cloned varying lengths of the 5-flanking region of the XAF1 gene into luciferase reporter vectors, and we evaluated their promoter activities. A transcription silencer was found between the ؊592-and ؊1414-nucleotide region that was rich in nGAAn/nTTCn elements (where n indicates G, A, T, or C). A high affinity and functional HSF1-binding element within the ؊862/؊821-nucleotide region was determined by electrophoretic mobility shift assay and chromatin immunoprecipitation assay. Inactivation of this "heat-shock element" by either site-directed mutation or an HSF1 inhibitor, pifithrin-␣, restored the promoter activity of the silencer structure. Moreover, pretreatment with antioxidants suppressed HSF1 binding activity and increased the transcriptional activity and expression of XAF1. These findings suggested that endogenous stress pressure in cancer cells sustained the high level expression of HSF1 and subsequently suppressed XAF1 expression, implicating the synergized effect of two anti-apoptotic protein families, HSP and inhibitors of apoptosis, in cytoprotection under stress circumstances.Heat-shock proteins (HSPs) 2 are conserved molecules present in all prokaryotes and eukaryotes (1, 2). The expression of these proteins is very low under normal physiological conditions and can be induced by stress factors, including physiological (growth factors, oxidative stress, and hormonal stimulation), environmental (heat shock, heavy metals, and ultraviolet radiation), or pathological stimuli (inflammation and autoimmune reactions and viral, bacteriological, or parasitic infections) (3, 4). Some stress factors, such as oxidative stress, have been considered as tumorigenic agents at low concentrations (5, 6). The main function of HSPs is to operate as an intracellular chaperone for aberrantly folded or mutated proteins and to provide cytoprotection against the stress conditions (31). For this reason, the presence of a cellular stress response in cancer cells reduces their sensitivity to chemical stress caused by insufficient tumor perfusion of chemotherapeutic agents (2).Heat-shock transcription factors (HSFs or HSTFs) were originally characterized as regulators of the expression of the heat-shock protein, through binding to specific s...

To evaluate the fuel efficiency of road traffic, an approach that captures the characteristics of road traffic on the basis of floating car data (FCD) is proposed. In existing studies of fuel consumption, parameters such as speed, acceleration, and power demand have been adopted to represent the characteristics of traffic flows and vehicle activities. However, they are not suitable for use in the evaluation of fuel efficiency in a dynamic traffic network with various advanced traffic management alternatives. On the basis of a comprehensive analysis of the data collected by portable emission measurement systems and FCD collected in Beijing, it was found that the time distribution in vehicle-specific power (VSP) bins, that is, the VSP bin distribution, can well represent fuel consumption per unit of time. Furthermore, the combination of the VSP bin distribution and the average travel speed in a network can represent fuel consumption per unit of distance. According to these findings, the paper develops a method for evaluating the fuel efficiency for road traffic on the basis of defined indicators of fuel consumption and fuel consumption at the most efficient speed. A comparison of the estimated indicators and the real values indicates that the proposed approach performs well in evaluating the fuel efficiency of road traffic. This approach was applied to develop the temporal distribution of fuel efficiency for the West 2nd Ring Road in Beijing. Finally, the paper provides recommendations for expansion of this study by including more vehicle types and different rates of penetration of FCD.

A calibration technique for platoon dispersion parameters for the widely used TRANSYT platoon dispersion model is presented. This technique calibrates platoon dispersion factor, travel time factor, and smoothing factor directly from the average link travel time and its standard deviation and can capture practically all of the roadway and traffic conditions in the field such as road grades, curvature, parking, opposing flow interference, traffic volume, and other sources of impedance. The technique is especially suited for applications in advanced traffic management system networks in which the required link travel time data could be obtained on a real-time basis. TRANSYT’s implementation of two scenarios is examined. The first scenario inputs the calibrated platoon dispersion parameter, with the result being that the smoothing factor used by TRANSYT is different from the calibrated parameter. The second scenario inputs a revised platoon dispersion factor, which is designed to make the smoothing factor used by TRANSYT identical to the calibrated parameter. This examination induces a recommendation that the TRANSYT input card or its internal calculation procedure for platoon dispersion be revised so that the average link travel time in the geometric distributed platoon dispersion model is consistent with those from the same model. The calibration of platoon dispersion parameters with field-collected link travel time data shows that platoon dispersion parameters are different for different standard deviations of link travel times even on the same street, and, therefore, the platoon dispersion parameters must be calibrated on a site-specific basis.

We consider a family of N -parameter reductions of Benney's equations, introduced in Gibbons and Kodama (Gibbons J and Kodama Y 1994 Solving dispersionless Lax equations Proc. Singular Limits of Dispersive Waves (Nato ASI Adv. Sci. Inst. Ser. B: Phys. vol 320) (New York: Plenum) p 61) as a generalization of the dispersionless Lax equations. Using Geogdzhaev's method (Geogjaev V V [Geogdzhaev V V] 1994 The quasiclassical limit of the inverse scattering problem method Proc. Singular Limits of Dispersive Waves (Nato ASI Adv. Sci. Inst. Ser. B: Phys. vol 20) (New York: Plenum) p 53), we solve the initial value problem for the reduced system. This construction is carried out explicitly for the reduction associated with an elliptic curve.

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