The association between parent's and healthcare professional's behavior and children's coping and distress during venepuncture

Objectives: Examine the association between children’s distress and coping during venepuncture with parent’s and healthcare professional’s behavior in a sample from the UK. Methods: Fifty children aged 7–16 years accompanied by a carer were videotaped while having venepuncture. Verbalizations of children, parents, and healthcare professionals were coded using the Child–Adult Medical Procedure Interaction Scale-Revised. Results: Children’s distress was associated with child’s age, anxiety, and distress promoting behavior of adults (R2 = .91). Children’s coping was associated with age, anxiety, and coping promoting behaviors of adults (R2 = .57). Associations were stronger between healthcare professional’s behavior and child coping; and between parent’s behaviors and child distress. Empathizing, apologizing, and criticism were not frequently used by adults in this sample (<12%). Conclusion: This study supports and extends previous research showing adult’s behavior is important in children’s distress and coping during needle procedures. Clinical implications and methodological issues are discussed

Occam's Quantum Strop: Synchronizing and Compressing Classical Cryptic Processes via a Quantum Channel

A stochastic process's statistical complexity stands out as a fundamental property: the minimum information required to synchronize one process generator to another. How much information is required, though, when synchronizing over a quantum channel? Recent work demonstrated that representing causal similarity as quantum state-indistinguishability provides a quantum advantage. We generalize this to synchronization and offer a sequence of constructions that exploit extended causal structures, finding substantial increase of the quantum advantage. We demonstrate that maximum compression is determined by the process's cryptic order---a classical, topological property closely allied to Markov order, itself a measure of historical dependence. We introduce an efficient algorithm that computes the quantum advantage and close noting that the advantage comes at a cost---one trades off prediction for generation complexity.Comment: 10 pages, 6 figures; http://csc.ucdavis.edu/~cmg/compmech/pubs/oqs.ht

Understanding needle-related distress in children with cystic fibrosis

Objective. To explore the nature and management of needle-related distress in children and adolescents with cystic fibrosis (CF). Design. Qualitative study using semi-structured interviews. Methods. Fourteen child–parent dyads took part. Children (5 male; 9 female) had a mean age of 12.4 years (range 7–17) and were mostly diagnosed with CF at birth (N= 11). Frequency of needle procedures ranged from once to six times a year. Parents (3 male; 11 female) had a mean age of 41.5 years and were from a variety of socio-economic backgrounds. Interviews were transcribed and analysed using thematic analysis. Results. Most participants identified previous needle experiences and pain as related to their needle anxiety. Over half of parents and children considered ‘taking control’ to be the optimum coping strategy. The majority of parents and children thought inhaled nitrous oxide gas during needle procedures was helpful in managing needle-related distress. Parent and staff influences on needle-related distress are also examined. Conclusions. Needle-related distress in children with CF has a substantial impact on children and their parents, and may lead to management problems and treatment refusal. Psychological and pharmacological interventions could reduce distress and aid management

Extreme Quantum Advantage for Rare-Event Sampling

We introduce a quantum algorithm for efficient biased sampling of the rare events generated by classical memoryful stochastic processes. We show that this quantum algorithm gives an extreme advantage over known classical biased sampling algorithms in terms of the memory resources required. The quantum memory advantage ranges from polynomial to exponential and when sampling the rare equilibrium configurations of spin systems the quantum advantage diverges.Comment: 11 pages, 9 figures; http://csc.ucdavis.edu/~cmg/compmech/pubs/eqafbs.ht

Prediction, Retrodiction, and The Amount of Information Stored in the Present

We introduce an ambidextrous view of stochastic dynamical systems, comparing their forward-time and reverse-time representations and then integrating them into a single time-symmetric representation. The perspective is useful theoretically, computationally, and conceptually. Mathematically, we prove that the excess entropy--a familiar measure of organization in complex systems--is the mutual information not only between the past and future, but also between the predictive and retrodictive causal states. Practically, we exploit the connection between prediction and retrodiction to directly calculate the excess entropy. Conceptually, these lead one to discover new system invariants for stochastic dynamical systems: crypticity (information accessibility) and causal irreversibility. Ultimately, we introduce a time-symmetric representation that unifies all these quantities, compressing the two directional representations into one. The resulting compression offers a new conception of the amount of information stored in the present.Comment: 17 pages, 7 figures, 1 table; http://users.cse.ucdavis.edu/~cmg/compmech/pubs/pratisp.ht

Information Accessibility and Cryptic Processes: Linear Combinations of Causal States

We show in detail how to determine the time-reversed representation of a stationary hidden stochastic process from linear combinations of its forward-time $\epsilon$-machine causal states. This also gives a check for the $k$-cryptic expansion recently introduced to explore the temporal range over which internal state information is spread.Comment: 6 pages, 9 figures, 2 tables; http://users.cse.ucdavis.edu/~cmg/compmech/pubs/iacplcocs.ht

Optimizing Quantum Models of Classical Channels: The reverse Holevo problem

Given a classical channel---a stochastic map from inputs to outputs---the input can often be transformed to an intermediate variable that is informationally smaller than the input. The new channel accurately simulates the original but at a smaller transmission rate. Here, we examine this procedure when the intermediate variable is a quantum state. We determine when and how well quantum simulations of classical channels may improve upon the minimal rates of classical simulation. This inverts Holevo's original question of quantifying the capacity of quantum channels with classical resources. We also show that this problem is equivalent to another, involving the local generation of a distribution from common entanglement.Comment: 13 pages, 6 figures; http://csc.ucdavis.edu/~cmg/compmech/pubs/qfact.htm; substantially updated from v

A Closed-Form Shave from Occam's Quantum Razor: Exact Results for Quantum Compression

The causal structure of a stochastic process can be more efficiently transmitted via a quantum channel than a classical one, an advantage that increases with codeword length. While previously difficult to compute, we express the quantum advantage in closed form using spectral decomposition, leading to direct computation of the quantum communication cost at all encoding lengths, including infinite. This makes clear how finite-codeword compression is controlled by the classical process' cryptic order and allows us to analyze structure within the length-asymptotic regime of infinite-cryptic order (and infinite Markov order) processes.Comment: 21 pages, 13 figures; http://csc.ucdavis.edu/~cmg/compmech/pubs/eqc.ht