Screening for posttraumatic stress disorder: An evaluation of two self-report scales among crime victims.

The validity of the Impact of Events Scale (IES) and the Posttraumatic Stress Disorder (PTSD) Symptom Scale, Self-Report version (PSS-SR) was examined among crime victims. Both instruments performed well as screeners for PTSD. For the IES, sensitivity ranged between .93 and 1.00; for the PSS-SR, sensitivity ranged between .80 and .90. Specificity for the IES ranged between .78 and .84 and for the PSS-SR ranged between .84 and .88. Some individual items from the 2 scales performed just as well as the total scales. The authors conclude that either of these short self-report instruments or their individual items are suitable as screeners for PTSD, specifically in settings where mental health professionals are unavailable. Cross-validation of these results is necessary because of the small sample size in this study. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Safety and progress of recursive procedures

Temporal weakest precondions are introduced for calculational reasoning about the states encountered during execution of not-necessarily terminating recursive procedures. The formalism can distinguish error from useful nontermination. The precondition functions are constructed in a new and more elegant way. Healthiness laws are discussed briefly. Proof rules are introduced that enable calculational proofs of various safety and progress properties. The construction of the precondition functions is justified in an Appendix that provides the operational semantics.Dedicated to the memory of Jan van de Snepscheut     

Exploration and Exploitation in Innovation: Reframing the Interpretation

There has been a burgeoning literature about exploitation and exploration since March's seminal article in 1991. However, in reviewing the extant literature we find different interpretations of both concepts leading to ambiguity and even some inconsistency. This paper focuses in particular on the interpretation of exploration and exploitation in the literature on technological innovation. It addresses two critical research questions. First, what are the different interpretations of exploitation and exploration? Second, how can we set up a framework that reconciles these differences and reduces the ambiguity that we find in the literature? To answer these two questions, we first explain what the root causes of these different viewpoints are. Second, we provide a theoretical framework that integrates the different perspectives, sets up a new typology to define exploration and exploitation, identifies white spaces in the current research and provides guidance for future research.     

Understanding the Advantages of Open Innovation Practices in Corporate Venturing in Terms of Real Options

Part of the advantages of using open innovation (compared to closed innovation) in corporate venturing can be explained by applying the real options approach. Open innovation in risk‐laden activities such as corporate venturing has the following advantages: (i) benefits from early involvement in new technologies or business opportunities; (ii) delayed financial commitment; (iii) early exits reducing the downward losses; and (iv) delayed exit in case it spins off a venture. We furthermore argue that these benefits do not automatically materialize. Innovative firms have to learn new skills and routines to develop the full ‘real option’ potential of open innovation practices.     

Full CMOS continuous time filters for GSM applications

This paper describes full cmoscontinuous time filter design techniques which can meet the specifications commonly set for gsmapplications. First several cmosfilter design techniques are overviewed. The ota-ctechnique is discussed to some more detail. To overcome the main drawback of the lower total harmonic distortion in ota-ctechniques very linear operational transconductance amplifiers (ota)are required. Such an ota,together with the applied linearisation techniques is discussed. To fulfil high accuracy in cut- off frequencies of the filter an active tuning system is necessary. A new on- chip tuning system is presented. The paper concludes with a practical design example for the gsmsystem. Therein the different ota-ctechniques discussed are illustrated.     

Splitting forward simulations to copewith liveness

In the literature, the conditions on history variables or forward simulations that are related to liveness are expressed in terms of behaviours, and are stronger than convenient and necessary. In this paper, we propose alternative conditions on the simulation relation, which are expressed in terms of the next state relation, and are closely tied to the weak or strong fairness conditions of the specifications. The proof of soundness of this proposal is based on a new theorem that asserts the existence of a strongly fair scheduler for infinitely many alternatives. The theory is extended to simulations in which the concrete specification (occasionally) does fewer steps than the abstract specification it implements.     

Restoration of peroxisome formation in two conditional peroxisome-deficient mutants of Hansenula polymorpha during growth of cells on specific organic nitrogen sources

Expression of the peroxisome-deficient (Per^?) phenotype by per mutants of Hansenula polymorpha is shown to be dependent on specific environmental conditions. Analysis of our collection of constitutive and conditional per mutants showed that, irrespective of the carbon source used, the mutants invariably lacked functional peroxisomes when ammonium sulphate was used as a nitrogen source. However, in two temperature-sensitive (ts) mutants, per13-6^ts and per14-11^ts, peroxisomes were present at the restrictive temperature when cells were grown on organic nitrogen sources which are known to induce peroxisomes in wild-type cells, namely D -alanine (for both mutants) or methylamine (for per14-11^ts). These organelles displayed normal wild-type properties with respect to morphology, mode of development and protein composition. However, under these conditions not all the peroxisomal matrix proteins synthesized were correctly located inside peroxisomes. Detailed biochemical and (immuno) cytochemical analyses indicated that during growth of cells on methanol in the presence of either D -alanine or methylamine, a minor portion of these proteins (predominantly alcohol oxidase, dihydroxyacetone synthase and catalase) still resided in the cytosol. This residual cytosolic activity may explain the observation that the functional restoration of the two ts mutants is not complete under these conditions, as is reflected by the retarded growth of the cells in batch cultures on methanol.     

The fracture process of ultra-high strength polyethylene fibres

The fracture behaviour of ultra-high strength polyethylene fibres has been investigated in dead load tests as well as by electron microscopical observation of the fracture surfaces. It was found that the fracture process in the fibres involves an activation energy of about 60 to 75 kJ mol^–1, which implies that the strength is mainly determined by the lateral bond strength between the molecules. Fracture is initiated at surface irregularities, such as kink bands, which leads to the formation of cracks with a fibrillated fracture surface. In this process the individual fibrils are cut through at topological defect regions in such fibrils, containing a relatively high concentration of trapped entanglements and chain ends. The ultimate strength of the polyethylene fibres was found to be inversely proportional to the square root of its diameter. Extrapolation to zero diameter yields a strength of 26 GPa for flawless fibres, which equals the theoretical strength of polyethylene.