Proving equivalence between imperative and MapReduce implementations using program transformations

Distributed programs are often formulated in popular functional frameworks like MapReduce, Spark and Thrill, but writing efficient algorithms for such frameworks is usually a non-trivial task. As the costs of running faulty algorithms at scale can be severe, it is highly desirable to verify their correctness. We propose to employ existing imperative reference implementations as specifications for MapReduce implementations. To this end, we present a novel verification approach in which equivalence between an imperative and a MapReduce implementation is established by a series of program transformations. In this paper, we present how the equivalence framework can be used to prove equivalence between an imperative implementation of the PageRank algorithm and its MapReduce variant. The eight individual transformation steps are individually presented and explained

An Integrated Literature Review of Time-on-Task Effects With a Pragmatic Framework for Understanding and Improving Decision-Making in Multidisciplinary Oncology Team Meetings

Multidisciplinary oncology team meetings (MDMs) or tumor boards, like other MDMs in healthcare, facilitate the incorporation of diverse clinical expertise into treatment planning for patients. Decision-making (DM) in relation to treatment planning in MDMs is carried out repeatedly until all patients put forward for discussion have been reviewed. Despite continuing financial pressure and staff shortages, the workload of cancer MDMs, and therefore meeting duration continue to increase (up to 5 h) with patients often receiving less than 2 min of team input. This begs the question as to whether the current set-up is conducive to achieve optimal DM, which these multi-specialty teams were set out to achieve in the first place. Much of what it is known, however, about the effects of prolonged cognitive activity comes from various subfields of science, leaving a gap in applied knowledge relating to complex healthcare environments. The objective of this review was thus to synthesize theory, evidence and clinical practice in order to bring the current understanding of prolonged, repeated DM into the context of cancer MDMs. We explore how and why time spent on a task affects performance in such settings, and what strategies can be employed by cancer teams to counteract negative effects and improve quality and safety. In the process, we propose a pragmatic framework of repeated DM that encompasses the strength, the process and the cost-benefit models of self-control as applied to real-world contexts of cancer MDMs. We also highlight promising research avenues for closing the research-to-practice gap. Theoretical and empirical evidence reviewed in this paper suggests that over prolonged time spent on a task, repeated DM is cognitively taxing, leading to performance detriments. This deterioration is associated with various cognitive-behavioral pitfalls, including decreased attentional capacity and reduced ability to effectively evaluate choices, as well as less analytical DM and increased reliance on heuristics. As a short to medium term improvement for ensuring safety, consistently high quality of care for all patients, and the clinician wellbeing, future research and interventions in cancer MDMs should address time-on-task effects with a combination of evidence-based cognitive strategies. We propose in this review multiple measures that range from food intake, short breaks, rewards, and mental exercises. As a long term imperative, however, capacity within cancer services needs to be reviewed as well as how best to plan workforce development and service delivery models to achieve population coverage whilst maintaining safety and quality of care. Hence the performance detriments that arise in healthcare workers as a result of the intensity (time spent on a task) and complexity of the workload require not only more research, but also wider regulatory focus and recognition

On the analytical approximation to the GLAP evolution at small x and moderate Q^2

Comparing the numerically evaluated solution to the leading order GLAP equations with its analytical small-x approximation we have found that in the domain covered by a large fraction of the HERA data the analytic approximation has to be augmented by the formally non-leading term which has been usually neglected. The corrected formula fits the data much better and provides a natural explanation of some of the deviations from the $\sigma$ scaling observed in the HERA kinematical range.Comment: LaTeX, 13 pages including 6 figures, figure 5 replaced, to appear in Phys. Lett.

The first author takes it all? Solutions for crediting authors more visibly, transparently, and free of bias

With the seventh edition of the publication manual of the American Psychological Association (APA), the APA style now prescribes bias-free language and encourages accessibility even to non-academic audiences. However, even with the newest guidelines, the way we credit authors in psychology remains anachronistic, intransparent, and prone to conflict. It still relies on a sequence-determines-credit approach in the byline, which concurrently is contradicted by the option to consider the last author as the position of the principal investigator depending on the field or journal. Scholars from various disciplines have argued that relying on such norms introduces a considerable amount of error when stakeholders rely on articles for career-relevant decisions. Given the existing recommendations towards a credit-based system, ignoring those issues will further promote bias that could be avoided with rather minor changes to the way we perceive authorship. In this article, we introduce a set of easy-to-implement changes to the manuscript layout that value contribution rather than position. Aimed at fostering transparency, accountability, and equality between authors, establishing those changes would likely benefit all stakeholders in contemporary psychological science

Nonperturbative versus perturbative effects in generalized parton distributions

Generalized parton distributions (GPDs) are studied at the hadronic (nonperturbative) scale within different assumptions based on a relativistic constituent quark model. In particular, by means of a meson-cloud model we investigate the role of nonperturbative antiquark degrees of freedom and the valence quark contribution. A QCD evolution of the obtained GPDs is used to add perturbative effects and to investigate the GPDs' sensitivity to the nonperturbative ingredients of the calculation at larger (experimental) scale.Comment: 17 pages, 10 figures; submitted to Phys. Rev.

Beobachtungsstudie ärztlicher und pflegerischer Aktivitäten in der Notaufnahme

Background!#!Comprehensive and systematic assessments of nurse and physician activities in the emergency department (ED) are lacking for German-speaking countries.!##!Objectives!#!Assessment of work activities of ED nurses and physicians with particular focus on frequencies of direct patient contact as well as rates of activity changes.!##!Material and methods!#!We employed standardized assessments of work activities using participant observations (90 min each) among nurses and physicians during their regular shifts. The setting was an interdisciplinary ED of a Southern German academic hospital. Observed activities were classified according to an established system and recorded with time stamps. Overall, 160 observation sessions were conducted (with an observation time of approximately 240 h; 99 among nurses, 61 among physicians).!##!Results!#!Physicians spent 30% of their working time in direct patient contact, nurses 44%. Concerning individual activities, the largest proportions of physicians' work time were allocated to documentation and writing (29.3%), communication with ED staff (16.9%) and patients (13.6%). Nurses were engaged in therapeutic and treatment activities (27.6%) and internal communication (17.9%) most of the time. Individual activities were highly fragmented: On average, we recorded 41.3 activities per hour with an average duration of 1.5 min. Nurses had significantly shorter activity durations than ED physicians (F[df = 1] = 4.5, p = 0.04). Activity-specific subanalyses revealed differences that could be attributed to professional roles in ED work.!##!Conclusion!#!Our results provide reliable and comprehensive insights into the distribution and duration of physician and nurse activities in clinical care in a German ED. Future work and design projects should focus particularly on effects of ED work time allocation on performance and work stress of ED staff as well as on safety and quality of ED patient care

Universality for 2D Wedge Wetting

We study 2D wedge wetting using a continuum interfacial Hamiltonian model which is solved by transfer-matrix methods. For arbitrary binding potentials, we are able to exactly calculate the wedge free-energy and interface height distribution function and, thus, can completely classify all types of critical behaviour. We show that critical filling is characterized by strongly universal fluctuation dominated critical exponents, whilst complete filling is determined by the geometry rather than fluctuation effects. Related phenomena for interface depinning from defect lines in the bulk are also considered.Comment: 4 pages, 1 figur