Streptogramin- and tetracycline-responsive dual regulated expression of p27Kip1 sense and antisense enables positive and negative growth control of Chinese hamster ovary cells

We constructed a dual regulated expression vector cassette (pDuoRex) whereby two heterologous genes can be independently regulated via streptogramin- and tetracycline-responsive promoters. Two different constructs containing growth-promoting and growth-inhibiting genes were stably transfected in recombinant Chinese hamster ovary (CHO) cells that express the streptogramin- and tetracycline-dependent transactivators in a dicistronic configuration. An optimally balanced heterologous growth control scenario was achieved by reciprocal expression of the growth-inhibiting human cyclin-dependent kinase inhibitor p27Kip1 in sense (p27Kip1S) and antisense (p27Kip1AS) orientation. Exclusive expression of p27Kip1S resulted in complete G1-phase-specific growth arrest, while expression of only p27Kip1AS showed significantly increased proliferation compared to control cultures (both antibiotics present), presumably by decreasing host cell p27Kip1 expression. In a second system, a derivative of pDuoRex encoding streptogramin-responsive expression of the growth-promoting SV40 small T antigen (sT) and tetracycline-regulated expression of p27Kip1 was stably transfected into CHO cells. Expression of sT alone resulted in an increase in cell proliferation, but the expression of p27Kip1 failed to provide the expected G1-specific growth arrest despite having demonstrated expression of the protein. This illustrates the difficulty in balancing the complex pathways underlying cell proliferation control through the expression of two functionally distinct genes involved in those pathways, and how a single-gene sense/antisense approach using pDuoRex can overcome this barrier to complete metabolic engineering control.

Exact and analytic-numerical solutions of lagging models of heat transfer in a semi-infinite medium

Different non-Fourier models of heat conduction have been considered in recent years, in a growing area of applications, to model microscale and ultrafast, transient, nonequilibrium responses in heat and mass transfer. In this work, using Fourier transforms, we obtain exact solutions for different lagging models of heat conduction in a semi-infinite domain, which allow the construction of analytic-numerical solutions with prescribed accuracy. Examples of numerical computations, comparing the properties of the models considered, are presented.

Carbon–carbon asymmetric aqueous capacitor by pseudocapacitive positive and stable negative electrodes

An asymmetric aqueous capacitor was constructed by employing zeolite-templated carbon (ZTC) as a pseudocapacitive positive electrode and KOH-activated carbon as a stable negative electrode. The asymmetric capacitor can be operated with the working voltage of 1.4 V, and exhibits an energy density that is comparable to those of conventional capacitors utilizing organic electrolytes, thanks to the large pseudocapacitance of ZTC. Despite relatively thick electrode (0.2 mm) configuration, the asymmetric capacitor could be well operated under a current density of 500 mA g −1.

Understanding Adolescents’ Positive and Negative Developmental Experiences in Sport

The purpose of this study was to gain understanding of adolescents’ positive and negative developmental experiences in sport. Twenty-two purposefully sampled adolescent competitive swimmers participated in a semistructured qualitative interview. Content analysis led to the organization of meaning units into themes and categories (Patton, 2002). Athletes suggested their sport involvement facilitated many positive developmental experiences (i.e., related to challenge, meaningful adult and peer relationships, a sense of community, and other life experiences) and some negative developmental experiences (i.e., related to poor coach relationships, negative peer influences, parent pressure, and the challenging psychological environment of competitive sport). Findings underline the important roles of sport programmers, clubs, coaches, and parents in facilitating youths’ positive developmental experiences in sport, while highlighting numerous important directions for future research. Implications for coach training and practice are outlined.

Cocaine and a changing brain : meeting summary : Ernest Morial Convention Center, New Orleans, LA, October 25, 1997 : sponsored by Division of Basic Research, National Institute on Drug Abuse, National Institutes of Health /

"January 1999"--P. [4] of cover.

Social security and the changing roles of men and women /

Summary (31 p.) inserted at end

Bituminous coal and lignite; changing patterns in distribution and markets.

Mode of access: Internet.

3rd annual Electronic Book 2000 Conference and Show : changing the fundamentals of reading, proceedings /

"September 2000."

Application of the hypothesis of dissolved ice to the freezing of water and of dilute solutions.

Hudson, C.S., cl. of 1901.

Key to the Complete system of mensuration of superfices and solids : containing solutions to all the problems and questions therein contained : calculated for the use of schools, academies, and private learners /

Mode of access: Internet.

Exact and approximate Bayesian solutions for inference about variance components and multivariate inadmissibility : final report for period 1 May 1972-1 January 1976 /

Performing organization: Dept. of Statistics, University of Michigan.

Is Mindfulness Beneficial for Job Performance Following Positive and Negative Affective Events? The Attenuating Role of Mindfulness on Self-Serving Bias

Thesis (Ph.D.)--University of Washington, 2016-05

An integrated cognitive model of panic disorder: The role of positive and negative cognitions

One reason for the neglect of the role of positive factors in cognitive-behavioural therapy (CBT) may relate to a failure to develop cognitive models that integrate positive and negative cognitions. Bandura [Psychol. Rev. 84 (1977) 191; Anxiety Res. 1 (1988) 77] proposed that self-efficacy beliefs mediate a range of emotional and behavioural outcomes. However, in panic disorder, cognitively based research to date has largely focused on catastrophic misinterpretation of bodily sensations. Although a number of studies support each of the predictions associated with the account of panic disorder that is based on the role of negative cognitions, a review of the literature indicated that a cognitively based explanation of the disorder may be considerably strengthened by inclusion of positive cognitions that emphasize control or coping. Evidence to support an Integrated Cognitive Model (ICM) of panic disorder was examined and the theoretical implications of this model were discussed in terms of both schema change and compensatory skills accounts of change processes in CBT. (C) 2004 Elsevier Ltd. All rights reserved.