Experiences of cognitive behavioural therapy formulation in clients with depression

AbstractWhile clinicians have described the benefits of using formulations within therapy, little is understood about the client's experience of the formulation process. Cognitive behaviour therapy (CBT) is currently the treatment of choice for many adult mental health difficulties. However, research exploring clients’ experiences of CBT formulation is very limited. The present study set out to explore experiences of CBT formulation in clients with depression. Seven participants were interviewed and the data analysed using Thematic Analysis. The analysis identified key themes such as: ‘Feeling trapped or restricted by depression’, ‘The development of the formulation – from coming to my own conclusions to something the therapist developed’, ‘From negative to mixed feelings: emotional reactions to the formulation during the therapeutic process’ and ‘A new journey: towards making a new sense of oneself’. The results of the study highlight the personal and emotional challenge of the formulation process for clients.</jats:p

Reachability for dynamic parametric processes

In a dynamic parametric process every subprocess may spawn arbitrarily many, identical child processes, that may communicate either over global variables, or over local variables that are shared with their parent. We show that reachability for dynamic parametric processes is decidable under mild assumptions. These assumptions are e.g. met if individual processes are realized by pushdown systems, or even higher-order pushdown systems. We also provide algorithms for subclasses of pushdown dynamic parametric processes, with complexity ranging between NP and DEXPTIME.Comment: 31 page

CARET analysis of multithreaded programs

Dynamic Pushdown Networks (DPNs) are a natural model for multithreaded programs with (recursive) procedure calls and thread creation. On the other hand, CARET is a temporal logic that allows to write linear temporal formulas while taking into account the matching between calls and returns. We consider in this paper the model-checking problem of DPNs against CARET formulas. We show that this problem can be effectively solved by a reduction to the emptiness problem of B\"uchi Dynamic Pushdown Systems. We then show that CARET model checking is also decidable for DPNs communicating with locks. Our results can, in particular, be used for the detection of concurrent malware.Comment: Pre-proceedings paper presented at the 27th International Symposium on Logic-Based Program Synthesis and Transformation (LOPSTR 2017), Namur, Belgium, 10-12 October 2017 (arXiv:1708.07854

A Framework to Synergize Partial Order Reduction with State Interpolation

We address the problem of reasoning about interleavings in safety verification of concurrent programs. In the literature, there are two prominent techniques for pruning the search space. First, there are well-investigated trace-based methods, collectively known as "Partial Order Reduction (POR)", which operate by weakening the concept of a trace by abstracting the total order of its transitions into a partial order. Second, there is state-based interpolation where a collection of formulas can be generalized by taking into account the property to be verified. Our main contribution is a framework that synergistically combines POR with state interpolation so that the sum is more than its parts

Symbolic Partial-Order Execution for Testing Multi-Threaded Programs

We describe a technique for systematic testing of multi-threaded programs. We combine Quasi-Optimal Partial-Order Reduction, a state-of-the-art technique that tackles path explosion due to interleaving non-determinism, with symbolic execution to handle data non-determinism. Our technique iteratively and exhaustively finds all executions of the program. It represents program executions using partial orders and finds the next execution using an underlying unfolding semantics. We avoid the exploration of redundant program traces using cutoff events. We implemented our technique as an extension of KLEE and evaluated it on a set of large multi-threaded C programs. Our experiments found several previously undiscovered bugs and undefined behaviors in memcached and GNU sort, showing that the new method is capable of finding bugs in industrial-size benchmarks.Comment: Extended version of a paper presented at CAV'2

DNA binding activities of the Herves transposase from the mosquito Anopheles gambiae

Determining the mechanisms by which transposable elements move within a genome increases our understanding of how they can shape genome evolution. Class 2 transposable elements transpose via a 'cut-and-paste' mechanism mediated by a transposase that binds to sites at or near the ends of the transposon. Herves is a member of the hAT superfamily of class 2 transposons and was isolated from Anopheles gambiae, a medically important mosquito species that is the major vector of malaria in sub-Saharan Africa. Herves is transpositionally active and intact copies of it are found in field populations of A gambiae. In this study we report the binding activities of the Herves transposase to the sequences at the ends of the Herves transposon and compare these to other sequences recognized by hAT transposases isolated from other organisms. We identified the specific DNA-binding sites of the Herves transposase. Active Herves transposase was purified using an Escherichia coli expression system and bound in a site-specific manner to the subterminal and terminal sequences of the left and right ends of the element, respectively, and also interacted with the right but not the left terminal inverted repeat. We identified a common subterminal DNA-binding motif (CG/AATTCAT) that is critical and sufficient for Herves transposase binding. The Herves transposase binds specifically to a short motif located at both ends of the transposon but shows differential binding with respect to the left and right terminal inverted repeats. Despite similarities in the overall structures of hAT transposases, the regions to which they bind in their respective transposons differ in sequence ensuring the specificity of these enzymes to their respective transposon. The asymmetry with which the Herves terminal inverted repeats are bound by the transposase may indicate that these differ in their interactions with the enzyme.https://doi.org/10.1186/1759-8753-2-

Reasoning about Threads with Bounded Lock Chains

The problem of model checking threads interacting purely via the standard synchronization primitives is key for many concurrent program analyses, particularly dataflow analysis. Unfortunately, it is undecidable even for the most commonly used synchronization primitive, i.e., mutex locks. Lock usage in concurrent programs can be characterized in terms of lock chains, where a sequence of mutex locks is said to be chained if the scopes of adjacent (non-nested) mutexes overlap. Although the model checking problem for fragments of Linear Temporal Logic (LTL) is known to be decidable for threads interacting via nested locks, i.e., chains of length one, these techniques don’t extend to pro-grams with non-nested locks used in crucial applications like databases and device drivers. We exploit the fact that lock usage patterns in real life programs do not produce unbounded lock chains. For such a framework, we show, by using the new concept of Lock Causality Automata (LCA), that pre∗-closures of regular sets of states can be computed efficiently. Leveraging this new technique then allows us to formulate decision procedures for model checking threads communicating via bounded lock chains for fragments of LTL. Our new results narrow the decidability gap for LTL model checking of threads communicating via locks by pro-viding a more refined characterization for it in terms of boundedness of lock chains rather than the current state-of-the-art, i.e., nestedness of locks (chains of length one).