Virtual reality exposure therapy (VRET) is a promising treatment for patients with fear of driving. The present pilot study is the first one focusing on behavioral effects of VRET on patients with ...fear of driving as measured by a post-treatment driving test in real traffic.
The therapy followed a standardized manual including psychotherapeutic and medical examination, two preparative psychotherapy sessions, five virtual reality exposure sessions, a final behavioral avoidance test (BAT) in real traffic, a closing session, and two follow-up phone assessments after six and twelve weeks. VRE was conducted in a driving simulator with a fully equipped mockup. The exposure scenarios were individually tailored to the patients' anxiety hierarchy. A total of 14 patients were treated. Parameters on the verbal, behavioral and physiological level were assessed.
The treatment was helpful to overcome driving fear and avoidance. In the final BAT, all patients mastered driving tasks they had avoided before, 71% showed an adequate driving behavior as assessed by the driving instructor, and 93% could maintain their treatment success until the second follow-up phone call. Further analyses suggest that treatment reduces avoidance behavior as well as symptoms of posttraumatic stress disorder as measured by standardized questionnaires (Avoidance and Fusion Questionnaire: p < .10, PTSD Symptom Scale-Self Report: p < .05).
VRET in driving simulation is very promising to treat driving fear. Further research with randomized controlled trials is needed to verify efficacy. Moreover, simulators with lower configuration stages should be tested for a broad availability in psychotherapy.
The Maxwell–Stefan (M–S) formulation is shown to be the most convenient and general way of describing diffusion within zeolite structures. This theory goes a long way to explain the observed various ...types of dependencies of the Fick diffusivity with sorbate loading. For mixture diffusion within zeolites, the M–S theory provides clues for the development of novel separation techniques that rely on diffusion selectivity. We illustrate this aspect by considering a number of practical applications in membrane permeation and chromatographic separations.
Rimonabant (SR141716) and the structurally related AM251 are widely used in pharmacological experiments as selective cannabinoid receptor CB(1) antagonists / inverse agonists. Concentrations of ...0.5-10 µM are usually applied in in vitro experiments. We intended to show that these drugs did not act at GABA(A) receptors but found a significant positive allosteric modulation instead.
Recombinant GABA(A) receptors were expressed in Xenopus oocytes. Receptors were exposed to AM251 or rimonabant in the absence and presence of GABA. Standard electrophysiological techniques were used to monitor the elicited ionic currents.
AM251 dose-dependently potentiated responses to 0.5 µM GABA at the recombinant α(1) β(2) γ(2) GABA(A) receptor with an EC(50) below 1 µM and a maximal potentiation of about eightfold. The Hill coefficient indicated that more than one binding site for AM251 was located in this receptor. Rimonabant had a lower affinity, but a fourfold higher efficacy. AM251 potentiated also currents mediated by α(1) β(2) , α(x) β(2) γ(2) (x = 2,3,5,6), α(1) β(3) γ(2) and α(4) β(2) δ GABA(A) receptors, but not those mediated by α(1) β(1) γ(2) . Interestingly, the CB(1) receptor antagonists LY320135 and O-2050 did not significantly affect α(1) β(2) γ(2) GABA(A) receptor-mediated currents at concentrations of 1 µM.
This study identified rimonabant and AM251 as positive allosteric modulators of GABA(A) receptors. Thus, potential GABAergic effects of commonly used concentrations of these compounds should be considered in in vitro experiments, especially at extrasynaptic sites where GABA concentrations are low.
This article is part of a themed section on Cannabinoids in Biology and Medicine. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-8. To view Part I of Cannabinoids in Biology and Medicine visit http://dx.doi.org/10.1111/bph.2011.163.issue-7.
Translational control plays a pivotal role in the regulation of the pluripotency network in embryonic stem cells, but its effect on reprogramming somatic cells to pluripotency has not been explored. ...Here, we show that eukaryotic translation initiation factor 4E (eIF4E) binding proteins (4E-BPs), which are translational repressors, have a multifaceted effect on the reprogramming of mouse embryonic fibroblasts (MEFs) into induced pluripotent stem cells (iPSCs). Loss of 4E-BP expression attenuates the induction of iPSCs at least in part through increased translation of p21, a known inhibitor of somatic cell reprogramming. However, MEFs lacking both p53 and 4E-BPs show greatly enhanced reprogramming resulting from a combination of reduced p21 transcription and enhanced translation of endogenous mRNAs such as Sox2 and Myc and can be reprogrammed through the expression of only exogenous Oct4. Thus, 4E-BPs exert both positive and negative effects on reprogramming, highlighting the key role that translational control plays in regulating this process.
Display omitted
•eIF4E-dependent translation is inhibited in pluripotent iPSCs and ESCs•4E-BPs are required for MEF reprogramming•Lack of 4E-BP1 and 4E-BP2 in p53-null MEFs leads to better reprogramming•Augmented translation of Sox2 and Myc mRNAs in TKO MEFs promotes reprogramming
This study reveals a functional interplay between 4E-BP-dependent translational control and the p53-p21 pathway that influences the synchronization of the transcriptional and translational changes occurring during reprogramming.
The Maxwell–Stefan (M–S), or corrected, diffusivity, in zeolites shows a variety of dependencies on the molecular loading or occupancies. This loading dependence is caused by a variety of factors, ...including zeolite topology, connectivity, and molecule–molecule interactions, that lead to a decrease or increase in the energy barrier for diffusion. Using the quasi-chemical theory of Reed and Ehrlich Surf. Sci. 105 (1981) 603–628 for surface diffusion on a square lattice as a basis, a simple model is developed to describe the loading dependence of the M–S diffusivity for a lattice topology with an arbitrary coordination number. The developed model is validated by kinetic Monte Carlo simulations in square, cubic and MFI zeolite topologies. Published Molecular Dynamics simulations of the loading dependence of M–S and self-diffusivities in a variety of zeolite topologies can be modeled using this approach. The M–S formulation allows accurate prediction of the transport and self-diffusivities in binary mixtures using only pure component diffusion data. For the prediction of mixture diffusion, correlation effects also need to be properly quantified and a scheme is suggested for estimation of these effects using data on M–S and self diffusivities of single components.
The first full-scale nutrient recovery installation in North America became operational in May 2009 at the Clean Water Service's Durham Advanced Wastewater Treatment Plant in Tigard, Oregon. ...Recovering ammonia and phosphorus from the dewatering side stream as struvite has a positive impact on plant operations. Significantly reducing the phosphorus recycle lowers the phosphorus loading on the plant, stabilizes biological phosphorus removal, reduces the amount of chemicals needed to remove phosphorus, reduces both the dry tonnes of biosolids generated and the phosphorus content of the biosolids, and provides revenue from the sale of the struvite. To increase struvite production and to decrease struvite potential in the digestion system, the Waste Activated Sludge Stripping To Remove Internal Phosphorus (WASSTRIP™) process was implemented full-scale in summer 2011. Results indicate a potential 60% increase in struvite production is achievable.
We develop an analytic solution of the Maxwell–Stefan equations describing steady-state diffusion of
n-component mixtures across a zeolite membrane. In the development of the analytic solution we ...assume Langmuirian behaviour of the pure components and that the mixture sorption can be calculated from the multicomponent Langmuir isotherm. Explicit expressions are derived for calculation of steady-state fluxes and the loading profiles in the membrane. The utility of the developed solution is illustrated by means of two illustrative examples involving permeation of alkane mixtures across an MFI membrane.
Investments in sewer rehabilitation must be based on inspection and evaluation of sewer conditions with respect to the severity of sewer damage and to environmental risks. This paper deals with the ...problems of forecasting the condition of sewers in a network from a small sample of inspected sewers. Transition functions from one into the next poorer condition class, which were empirically derived from this sample, are used to forecast the condition of sewers. By the same procedure, transition functions were subsequently calibrated for sub-samples of different types of sewers. With these transition functions, the most probable date of entering a critical condition class can be forecast from sewer characteristics, such as material, period of construction, location, use for waste and/or storm water, profile, diameter and gradient. Results are shown for the estimates about the actual condition of the Dresden sewer network and its deterioration in case of doing nothing about it. A procedure is proposed for scheduling the inspection dates for sewers which have not yet been inspected and for those which have been inspected before.
PDF
