Modality specific Type 2 theta production in the immobile rat.

The purpose of the present study was to compare the relative effectiveness of stimulation of different sensory modalities in eliciting Type 2 theta in the rat in the presence or absence of a ferret. Visual, auditory, and tactile stimuli were presented to rats in both conditions. Tactile stimulation produced more movement than either visual or auditory stimuli when the ferret was present. In both conditions, however, more Type 2 theta was observed in response to tactile or visual stimulation than to auditory stimulation. In the arousal condition, stimulation of tactile and auditory modalities resulted in significant increases in the amount of Type 2 theta produced. Input to the visual modality produced high levels of Type 2 theta production in both low- and high-arousal conditions. It is argued that Type 2 theta is not necessarily a precursor to movement but rather sensory processing while in a high state of arousal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Using Confidence Intervals to Compare Process Capability Indices

Process capability indices are widely used to measure process performance. In situations such as selecting a supplier and assessing process improvement, it is of interest to compare capability indices for two different processes or the same process before and after an adjustment. In this paper, we consider several methods for performing this comparison on the indices C_pk and C_pm. The methods are compared using a computer simulation. Recommendations are provided for selecting an appropriate method based on power and test size computations.     

Is high strength concrete more susceptible to explosive spalling than normal strength concrete in fire?

There is a belief, within the fire research community, that high strength concrete is more susceptible to explosive spalling than normal strength concrete. This impression is based on studying concrete properties and collecting experimental data from different research sources. But there are still doubts about the credibility of this conjecture due to the lack of integrated experimental research, particularly designed to address this issue. This paper represents the outcomes of experimental study involving normal and high strength concrete columns tested under fire. The columns were subjected to a constant load and to different values of axial restraint. The paper attempts to address the question of the susceptibility of normal and high strength concrete to explosive spalling under fire. Copyright © 2002 John Wiley & Sons, Ltd.     

Transient Behavior of a Thermoelectric Device Under the Hyperbolic Heat Conduction Model

The major objective of this work is to describe the dynamic thermal behavior of thermoelectric generators and refrigerators under the effect of the hyperbolic heat conduction model. In practical situations, these devices work under transient operating conditions due to the time change in the imposed current, voltage, and hot or cold temperatures. Results for transient temperature distributions were obtained for different parameters. The coefficient of performance was obtained as a function of time for increasing current flow.     

Utility of adenoviral-mediated Fas ligand gene transfer to modulate islet allograft survival

We examined the perioperative balance between oxygen delivery and oxygen consumption under hemodilution in 24 patients who underwent head and neck surgery of long duration and with massive blood loss. Intraoperative mixed venous oxygen saturation (SVO2), which decreased according to a decrease in hematocrit (Hct), was almost always kept above 60% when Hct was more than 20%. The longer the duration of surgery, the lower was SVO2 at the end of surgery. Postoperative SVO2 correlated positively with SVO2 at the end of surgery, and negatively with the duration of surgery and blood loss, but did not correlate with Hct. In 9 cases, SVO2 at the recovery from anesthesia decreased to below 60%, because oxygen consumption increased remarkably with shivering. These results suggest that in highly invasive head and neck surgery, the intraoperative minimum acceptable Hct level is 20%. On the other hand, there is no general postoperative minimum acceptable Hct level, because postoperative oxygen demand and supply balance depends on the degree of surgical invasion and increase of VO2. SVO2 at the end of surgery is useful in predicting postoperative oxygen demand and supply balance.     

Transient Thermal Stresses in an Orthotropic Cylinder under the Hyperbolic Heat Conduction Model

An important consideration in design involving high temperature variation is the determination of the thermal stresses developed. The numerical solution for thermoelastic transient response of orthotropic cylinder subjected to a constant temperature at the surface is presented. The thermoelastic equations with one relaxation time developed by Lord and Shulman with uncoupled thermoelasticity assumption are used in the present work. The hyperbolic heat conduction model is used for the prediction of the temperature history. Thermally induced displacement and stresses are determined. A numerical method based on implicit finite difference scheme is used to calculate the temperature, displacement, and stress distributions within the cylinder. Numerical examples for orthotropic, transverse isotropic, and isotropic cylinders were carried out for the stresses. Furthermore, the results of the numerical solution and the exact solution at the steady state condition are compared.     

ON THE PHASE-LAG EFFECT ON THE NONEQUILIBRIUM ENTROPY PRODUCTION

In this work, the effect of the phase lag in heat flux, under the effect of the hyperbolic heat conduction model, on the nonequilibrium entropy production is investigated. It is shown that the entropy production cannot be described using the classical form of the equilibrium entropy production where using this form leads to a violation of the second law of thermodynamics. Also, it is shown that in most practical applications, the difference between equilibrium and nonequilibrium temperature in the hyperbolic heat conduction model may be neglected. The effect of the phase lag in heat flux on the spacial and time variation in nonequilibrium entropy is studied.     

Pinching hysteretic response of yielding shear panel device

The paper describes a modeling technique of the hysteretic response of yielding shear panel device (YSPD). This device is used for seismic energy dissipation in frame structures. The generalized Bouc-Wen-Baber-Noori (BWBN) hysteretic model is adopted in this work. Simulink is used to develop the BWBN model of the YSPD. The model parameters are calibrated based on experimental results conducted on the YSPD. The developed hysteretic model of the YSPD is then incorporated in state-space approach to evaluate the response of dissipative structures. Assessment of effectiveness of the YSPD in alleviating structural response and the effect of pinching on the overall response of the structure is made.     

Mitochondrial Glycerol-3-Phosphate Acyltransferase-Dependent Phospholipid Synthesis Modulates Phospholipid Mass and IL-2 Production in Jurkat T Cells

Changes in glycerophospholipid metabolism with age and disease can have a profound effect on immune cell activation and effector function. We previously demonstrated that glycerol‐3‐phosphate acyltransferase‐1, the first and rate limiting step in de novo glycerophospholipid synthesis, plays a role in modulating murine T cell function. The resultant phenotype is characterized by decreased IL‐2 production, increased propensity toward apoptosis, and altered membrane glycerophospholipid mass similar to that of an aged T cell. Since T cells in previous experiments were harvested from GPAT‐1^?/? mice, questions remained as to what extent the macro environment of the model influenced the observed cellular phenotype. Therefore, we generated and phenotypically characterized a mitochondrial glycerol‐3‐phosphate acyltransferase (GPAM) deficient Jurkat T cell. Furthermore, this line was used to probe possible mechanisms by which GPAT‐1/GPAM regulates T cell function. We report here that many of the key dysfunctional characteristics of murine GPAT‐1^?/? T cells are recapitulated in the GPAMKD Jurkat T cell. We found striking decreased IL‐2 production along with altered phospholipid mass and increased incidence of apoptosis. Since PtdOH is an indirect downstream product of GPAM, we attempted to rescue IL‐2 production with PtdOH supplementation; however, this addition did not return IL‐2 production to normal levels. Interestingly, we did find significantly decreased Zap‐70 phosphorylation following stimulation, suggesting that GPAM deficiency may alter membrane based stimulatory signaling. These data show for the first time that GPAM deficiency results in an inherent defect in Jurkat T cell function and glycerophospholipid composition and that this defect cannot be rescued by addition of exogenous PtdOH.     

Progressive collapse analysis of steel frames: Simplified procedure and explicit expression for dynamic increase factor

Progressive collapse refers to a phenomenon in which local damage in a primary structural element leads to total or partial structural system failure. When investigating the progressive collapse of structures, nonlinear dynamic procedures lead to more accurate results than static procedures. However, nonlinear dynamic procedures are very complicated and the evaluation or validation of the results can become very time consuming. Therefore, it is better to use simpler methods. For static analyses, the gravity force applied to the removed column bay should be multiplied by a constant factor of two. However, using a constant dynamic increase factor (DIF) is only appropriate for elastic systems. According to the optimal design of structures, the assumption of elastic behavior after column removal is conservative. Thus, it is necessary to establish an expression for DIF that considers inelastic responses. In this paper, a simplified analysis procedure for the progressive collapse analysis of steel structures is presented using the load displacement and capacity curve of a fixed end steel beam. The results of the proposed method are in good agreement with nonlinear dynamic analysis results. Also, the capacity curve, obtained by dividing the accumulated area under the nonlinear static load displacement curve by the corresponding displacement of the column removed point, is used to predict the progressive collapse resistance of the column removed structure. Finally, an explicit expression for the DIF is established for elastic-perfectly plastic and elastic plastic with catenary action behavior.