A meta-analysis of transdiagnostic cognitive behavioural therapy in the treatment of child and young person anxiety disorders

Background: Previous meta-analyses of cognitive-behavioural therapy (CBT) for children and young people with anxiety disorders have not considered the efficacy of transdiagnostic CBT for the remission of childhood anxiety. Aim: To provide a meta-analysis on the efficacy of transdiagnostic CBT for children and young people with anxiety disorders. Methods: The analysis included randomized controlled trials using transdiagnostic CBT for children and young people formally diagnosed with an anxiety disorder. An electronic search was conducted using the following databases: ASSIA, Cochrane Controlled Trials Register, Current Controlled Trials, Medline, PsycArticles, PsychInfo, and Web of Knowledge. The search terms included “anxiety disorder(s)”, “anxi∗”, “cognitive behavio∗, “CBT”, “child∗”, “children”, “paediatric”, “adolescent(s)”, “adolescence”, “youth” and “young pe∗”. The studies identified from this search were screened against the inclusion and exclusion criteria, and 20 studies were identified as appropriate for inclusion in the current meta-analysis. Pre- and posttreatment (or control period) data were used for analysis. Results: Findings indicated significantly greater odds of anxiety remission from pre- to posttreatment for those engaged in the transdiagnostic CBT intervention compared with those in the control group, with children in the treatment condition 9.15 times more likely to recover from their anxiety diagnosis than children in the control group. Risk of bias was not correlated with study effect sizes. Conclusions: Transdiagnostic CBT seems effective in reducing symptoms of anxiety in children and young people. Further research is required to investigate the efficacy of CBT for children under the age of 6

Spin-dependent transport in metal/semiconductor tunnel junctions

This paper describes a model as well as experiments on spin-polarized tunnelling with the aid of optical spin orientation. This involves tunnel junctions between a magnetic material and gallium arsenide (GaAs), where the latter is optically excited with circularly polarized light in order to generate spin-polarized carriers. A transport model is presented that takes account of carrier capture in the semiconductor surface states, and describes the semiconductor surface in terms of a spin-dependent energy distribution function. The so-called surface spin-splitting can be calculated from the balance of the polarized electron and hole flow in the semiconductor subsurface region, the polarized tunnelling current across the tunnel barrier between the magnetic material and the semiconductor surface, and the spin relaxation at the semiconductor surface. Measurements are presented of the circular-polarization-dependent photocurrent (the so-called helicity asymmetry) in thin-film tunnel junctions of Co/Al2O3/GaAs. In the absence of a tunnel barrier, the helicity asymmetry is caused by magneto-optical effects (magnetic circular dichroism). In the case where a tunnel barrier is present, the data cannot be explained by magneto-optical effects alone; the deviations provide evidence that spin-polarized tunnelling due to optical spin orientation occurs. In Co/τ-MnAl/AlAs/GaAs junctions no deviations from the magneto-optical effects are observed, most probably due to the weak spin polarization of τ-MnAl along the tunnelling direction; the latter is corroborated by bandstructure calculations. Finally, the application of photoexcited GaAs for spin-polarized tunnelling in a scanning tunnelling microscope is discussed.

Life in the Polar Winter - Strategies of Survival

The perception of the polar winter as a period in which organisms have to struggle for survival is common among people living almost exclusively outside the polar regions, even if sometimes in areas with winter resembling the polar winter. ... For arctic organisms, endemic to and wintering in the far North, the polar winter possibly has a different significance. For these organisms it is often a period of rest, during which they conserve energy and prepare for reproduction in the coming feeding season. Until the last decades of this century, we knew little about the significance of the polar winter for organisms that live there year-round. For migratory species it is obviously a rather intolerable season, but how resident species survive and live through the winter was unknown. ... The series of eight papers presented here ... stem from a multidisciplinary symposium organized by the Arctic Centre of the University of Groningen on the occasion of the 375th anniversary of this university of 1989. ... The guiding question of this symposium was: How do humans and their living resources survive the polar winter? As the resources are both terrestrial and marine, both are discussed when presenting organisms from different trophic levels. ... This series of papers concludes with a study of the successes and misfortunes of western Europeans wintering in the High Arctic in the 16th and 17th centuries and an article about Russian trappers during the 18th and 19th centuries wintering in Spitsburgen. ..

Spatial heterogeneity and irreversible vegetation change in semi-arid grazing systems

Recent theoretical studies have shown that spatial redistribution of surface water may explain the occurrence of patterns of alternating vegetated and degraded patches in semiarid grasslands. These results implied, however, that spatial redistribution processes cannot explain the collapse of production on coarser scales observed in these systems. We present a spatially explicit vegetation model to investigate possible mechanisms explaining irreversible vegetation collapse on coarse spatial scales. The model results indicate that the dynamics of vegetation on coarse scales are determined by the interaction of two spatial feedback processes. Loss of plant cover in a certain area results in increased availability of water in remaining vegetated patches through run-on of surface water, promoting within-patch plant production. Hence, spatial redistribution of surface water creates negative feedback between reduced plant cover and increased plant growth in remaining vegetation. Reduced plant cover, however, results in focusing of herbivore grazing in the remaining vegetation. Hence, redistribution of herbivores creates positive feedback between reduced plant cover and increased losses due to grazing in remaining vegetated patches, leading to collapse of the entire vegetation. This may explain irreversible vegetation shifts in semiarid grasslands on coarse spatial scales

NOVA: A new multi-level logic simulator

A new logic simulator that was developed at the NASA Space Engineering Research Center for VLSI Design was described. The simulator is multi-level, being able to simulate from the switch level through the functional model level. NOVA is currently in the Beta test phase and was used to simulate chips designed for the NASA Space Station and the Explorer missions. A new algorithm was devised to simulate bi-directional pass transistors and a preliminary version of the algorithm is presented. The usage of functional models in NOVA is also described and performance figures are presented

Regional differences in the consumption of Benzodiazepines: an analysis from Belgium

Peer reviewe

Fuel-Responsive Allosteric DNA-Based Aptamers for the Transient Release of ATP and Cocaine

We show herein that allostery offers a key strategy for the design of out-of-equilibrium systems by engineering allosteric DNA-based nanodevices for the transient loading and release of small organic molecules. To demonstrate the generality of our approach, we used two model DNA-based aptamers that bind ATP and cocaine through a target-induced conformational change. We re-engineered these aptamers so that their affinity towards their specific target is controlled by a DNA sequence acting as an allosteric inhibitor. The use of an enzyme that specifically cleaves the inhibitor only when it is bound to the aptamer generates a transient allosteric control that leads to the release of ATP or cocaine from the aptamers. Our approach confirms that the programmability and predictability of nucleic acids make synthetic DNA/RNA the perfect candidate material to re-engineer synthetic receptors that can undergo chemical fuel-triggered release of small-molecule cargoes and to rationally design non-equilibrium systems

A conformational study of peptides with the general structure Ac-L-Xaa-Pro-D-Xaa-L-Xaa-NH_2: spectroscopic evidence for a peptide with significant β-turn character in water and in dimethyl sulfoxide

Several tetrapeptides, Ac-Val-Pro-D-Ser-His-NH_2, in particular, show significant type II β-turn character in water and in dimethyl sulfoxide. Evidence for this turn population is provided by 2D-rotating frame nuclear Overhauser effect (ROESY) spectroscopy, ^1H NMR amide temperature coefficients, and circular dichroism (CD) studies. To further investigate which residues specifically contribute to the integrity of the turn, studies on 10 tetrapeptides, having the general sequence AC-LXaa-Pro-D-Xaa-L-Xaa-NH_2, are described. The results show the effects of sequence variations on the type II β-turn forming propensity of these peptides in solution. Conclusions from these studies indicate that a cooperative effect between a sterically hindered, β-branched amino acid at the (i) position and a small, non-β-branched D-amino acid at the (i+2) position promotes turn formation. Implications for use of these sequences as structural nucleation elements in de novo protein design are discussed