The Parallel Persistent Memory Model

We consider a parallel computational model that consists of $P$ processors, each with a fast local ephemeral memory of limited size, and sharing a large persistent memory. The model allows for each processor to fault with bounded probability, and possibly restart. On faulting all processor state and local ephemeral memory are lost, but the persistent memory remains. This model is motivated by upcoming non-volatile memories that are as fast as existing random access memory, are accessible at the granularity of cache lines, and have the capability of surviving power outages. It is further motivated by the observation that in large parallel systems, failure of processors and their caches is not unusual. Within the model we develop a framework for developing locality efficient parallel algorithms that are resilient to failures. There are several challenges, including the need to recover from failures, the desire to do this in an asynchronous setting (i.e., not blocking other processors when one fails), and the need for synchronization primitives that are robust to failures. We describe approaches to solve these challenges based on breaking computations into what we call capsules, which have certain properties, and developing a work-stealing scheduler that functions properly within the context of failures. The scheduler guarantees a time bound of $O(W/P_A + D(P/P_A) \lceil\log_{1/f} W\rceil)$ in expectation, where $W$ and $D$ are the work and depth of the computation (in the absence of failures), $P_A$ is the average number of processors available during the computation, and $f \le 1/2$ is the probability that a capsule fails. Within the model and using the proposed methods, we develop efficient algorithms for parallel sorting and other primitives.Comment: This paper is the full version of a paper at SPAA 2018 with the same nam

Separabelized Skyrme Interactions and Quasiparticle RPA

A finite rank separable approximation for the quasiparticle RPA with Skyrme interactions is applied to study the low lying quadrupole and octupole states in some S isotopes and giant resonances in some spherical nuclei. It is shown that characteristics calculated within the suggested approach are in a good agreement with available experimental data.Comment: 12 pages, 2 figures, proceedings of the Seventh School-Seminar on Heavy Ion Physics, Dubna, Russia, May 27-June 1, 2002; to appear in Physics of Atomic Nucle

Effectiveness of a Self-Management Intervention to Promote an Active Lifestyle in Persons With Long-Term Spinal Cord Injury: The HABITS Randomized Clinical Trial

Background. Most people with long-term spinal cord injury (SCI) have a very inactive lifestyle. Higher activity levels have been associated with health benefits and enhanced quality of life. Consequently, encouraging an active lifestyle is important and behavioral interventions are needed to establish durable lifestyle changes. Objective. The Healthy Active Behavioral Intervention in SCI (HABITS) study was aimed to evaluate the effectiveness of a structured self-management intervention to promote an active lifestyle in inactive persons with long-term SCI. Methods. This assessor-blinded randomized controlled trial was conducted at 4 specialized SCI units in the Netherlands. Sixty-four individuals with long-term SCI (>10 years), wheelchair-user and physically inactive, were included. Participants were randomized to either a 16-week self-management intervention consisting of group meetings and individual counseling and a book, or to a control group that only received information about active lifestyle by one group meeting and a book. Measurements were performed at baseline, 16 weeks, and 42 weeks. Primary outcome measures were self-reported physical activity and minutes per day spent in wheelchair driving. Secondary outcomes included perceived behavioral control (exercise self-efficacy, proactive coping), stages of change concerning exercise, and attitude toward exercise. Results. Mixed models analyses adjusted for age, sex, level of SCI, time since injury, baseline body mass index, and location did not show significant differences between the intervention and control groups on the primary and secondary outcomes (P ≥.05). Conclusions. A structured 16-week self-management intervention was not effective to change behavior toward a more active lifestyle and to improve perceived behavioral control, stages of change, and attitude

Submaximal physical strain and peak performance in handcycling versus handrim wheelchair propulsion

Study design: Experimental study in subjects with paraplegia and nondisabled subjects. Objective: To compare submaximal physical strain and peak performance in handcycling and handrim wheelchair propulsion in wheelchair-dependent and nondisabled control subjects Setting: Amsterdam, The Netherlands. Methods: Nine male subjects with paraplegia and 10 nondisabled male subjects performed two exercise tests on a motor-driven treadmill using a handrim wheelchair and attach-unit handcycle system. The exercise protocol consisted of two 4-min submaximal exercise bouts at 25 and 35 W, followed by 1-min exercise bouts with increasing power output until exhaustion. Results: Analysis of variance for repeated measures showed a significantly lower oxygen uptake (VO2), ventilation (Ve), heart rate (HR), rate of perceived exertion and a higher gross efficiency for handcycling at 35 W in both subject groups, while no significant differences were found at 25 W. Peak power output and peak V

The Impact of Ethnicity and Country of Birth on Inflammatory Bowel Disease Phenotype:A Prospective Cohort Study

Background and Aims: The number of patients with inflammatory bowel disease [IBD], of non-Caucasian descent in Western Europe, is increasing. We aimed to explore the impact of ethnicity and country of birth on IBD phenotype.Methods: IBD patients treated in the eight University Medical Centers in The Netherlands [Dutch IBD Biobank] were divided into two groups according to their ethnicity: 1] Caucasian patients of Western and Central European descent [CEU]; and 2] patients of non-Caucasian descent [non-CEU]. The non-CEU group was subdivided according to country of birth, into: born in The Netherlands or Western Europe [non-CEU European born]; or born outside Western-Europe who migrated to The Netherlands [non-CEU non-European born]. Both comparisons were analysed for phenotype differences [by chi-square test].Results: The Dutch IBD Biobank included 2921 CEU patients and 233 non-CEU patients. Non-CEU Crohn's disease [CD] patients more often had upper gastro-intestinal disease [16% vs 8%, p = 0.001] and anal stenosis [10% vs 4%, p = 0.002] than CEU CD patients. The use of anti-tumour necrosis factor [TNF] agents and immunomodulators was higher in non-CEU IBD patients than in CEU IBD patients [45% vs 38%, p = 0.042] and [77% vs 66%, p = 0.001], respectively. Non-CEU IBD patients born in Europe [n = 116] were diagnosed at a lower age than non-CEU IBD patients born outside Europe [n = 115] [at 22.7 vs 28.9 years old, p &lt;0.001].Conclusion: Non-Caucasians had more severe disease behaviour than Caucasians. Non-CEU patients born in Europe were diagnosed at a lower age with IBD than those born outside Europe who migrated to The Netherlands.</p

Photonuclear Reactions of Three-Nucleon Systems

We discuss the available data for the differential and the total cross section for the photodisintegration of $^3$He and $^3$H and the corresponding inverse reactions below $E_\gamma = 100$ MeV by comparing with our calculations using realistic $NN$ interactions. The theoretical results agree within the errorbars with the data for the total cross sections. Excellent agreement is achieved for the angular distribution in case of $^3$He, whereas for $^3$H a discrepancy between theory and experiment is found.Comment: 11 pages (twocolumn), 12 postscript figures included, uses psfig, RevTe

Handcycling: training effects of a specific dose of upper body endurance training in females

Purpose: This study aims to evaluate a handcycling training protocol based on ACSM guidelines in a well-controlled laboratory setting. Training responses of a specific dose of handcycling training were quantified in a homogeneous female subject population to obtain a more in depth understanding of physiological mechanisms underlying adaptations in upper body training. Methods: 22 female able-bodied participants were randomly divided in a training (T) and control group (C). T received 7-weeks of handcycling training, 3 × 30 min/week at 65 % heart rate reserve (HRR). An incremental handcycling test was used to determine local, exercise-specific adaptations. An incremental cycling test was performed to determine non-exercise-specific central/cardiovascular adaptations. Peak oxygen uptake (peakVO2), heart rate (peakHR) and power output (peakPO) were compared between T and C before and after training. Results: T completed the training sessions at 65 ± 3 % HRR, at increasing power output (59.4 ± 8.2 to 69.5 ± 8.9 W) over the training program. T improved on handcycling peakVO2 (+18.1 %), peakPO (+31.9 %), and peakHR (+4.0 %). No improvements were found in cycling parameters. Conclusion: Handcycling training led to local, exercise-specific improvements in upper body parameters. Results could provide input for the design of effective evidence-based training programs specifically aimed at upper body endurance exercise in females

Validity of the self-administered comorbidity questionnaire in patients with inflammatory bowel disease

Background: The International Consortium for Health Outcomes Measurement has selected the self-administered comorbidity questionnaire (SCQ) to adjust case-mix when comparing outcomes of inflammatory bowel disease (IBD) treatment between healthcare providers. However, the SCQ has not been validated for use in IBD patients. Objectives: We assessed the validity of the SCQ for measuring comorbidities in IBD patients. Design: Cohort study. Methods: We assessed the criterion validity of the SCQ for IBD patients by comparing patient-reported and clinician-reported comorbidities (as noted in the electronic health record) of the 13 diseases of the SCQ using Cohen’s kappa. Construct validity was assessed using the Spearman correlation coefficient between the SCQ and the Charlson Comorbidity Index (CCI), clinician-reported SCQ, quality of life, IBD-related healthcare and productivity costs, prevalence of disability, and IBD disease activity. We assessed responsiveness by correlating changes in the SCQ with changes in healthcare costs, productivity costs, quality of life, and disease activity after 15 months. Results: We included 613 patients. At least fair agreement (κ &gt; 0.20) was found for most comorbidities, but the agreement was slight (κ &lt; 0.20) for stomach disease [κ = 0.19, 95% CI (−0.03; 0.41)], blood disease [κ = 0.02, 95% CI (−0.06; 0.11)], and back pain [κ = 0.18, 95% CI (0.11; 0.25)]. Correlations were found between the SCQ and the clinician-reported SCQ [ρ = 0.60, 95% CI (0.55; 0.66)], CCI [ρ = 0.39, 95% CI (0.31; 0.45)], the prevalence of disability [ρ = 0.23, 95% CI (0.15; 0.32)], and quality of life [ρ = −0.30, 95% CI (−0.37; −0.22)], but not between the SCQ and healthcare or productivity costs or disease activity (|ρ| ⩽ 0.2). A change in the SCQ after 15 months was not correlated with a change in any of the outcomes.Conclusion: The SCQ is a valid tool for measuring comorbidity in IBD patients, but face and content validity should be improved before being used to correct case-mix differences.</p

The management of iron deficiency in inflammatory bowel disease

__Background__ Iron deficiency is a common and undertreated problem in inflammatory bowel disease (IBD). __Aim__ To develop an online tool to support treatment choice at the patient-specific level. __Methods__ Using the RAND/UCLA Appropriateness Method (RUAM), a European expert panel assessed the appropriateness of treatment regimens for a variety of clinical scenarios in patients with non-anaemic iron deficiency (NAID) and iron deficiency anaemia (IDA). Treatment options included adjustment of IBD medication only, oral iron supplementation, high-/low-dose intravenous (IV) regimens, IV iron plus erythropoietin-stimulating agent (ESA), and blood transfusion. The panel process consisted of two individual rating rounds and three plenary discussion meetings. __Results__ The panel reached agreement on 71% of treatment indications. 'No treatment' was never considered appropriate, and repeat treatment after previous failure was generally discouraged. For 98% of scenarios, at least one treatment was appropriate. Adjustment of IBD medication was deemed appropriate in all patients with active disease. Use of oral iron was mainly considered an option in NAID and mildly anaemic patients without disease activity. IV regimens were often judged appropriate, with high-dose IV iron being the preferred option in 77% of IDA scenarios. Blood transfusion and IV+ESA were indicated in exceptional cases only. __Conclusions__ The RUAM revealed high agreement amongst experts on the management of iron deficiency in patients with IBD. High-dose IV iron was more often considered appropriate than other options. To facilitate dissemination of the recommendations, panel outcomes were embedded in an online tool, accessible via http://ferroscope.com/

Phenotypic Variation and Bistable Switching in Bacteria

Microbial research generally focuses on clonal populations. However, bacterial cells with identical genotypes frequently display different phenotypes under identical conditions. This microbial cell individuality is receiving increasing attention in the literature because of its impact on cellular differentiation, survival under selective conditions, and the interaction of pathogens with their hosts. It is becoming clear that stochasticity in gene expression in conjunction with the architecture of the gene network that underlies the cellular processes can generate phenotypic variation. An important regulatory mechanism is the so-called positive feedback, in which a system reinforces its own response, for instance by stimulating the production of an activator. Bistability is an interesting and relevant phenomenon, in which two distinct subpopulations of cells showing discrete levels of gene expression coexist in a single culture. In this chapter, we address techniques and approaches used to establish phenotypic variation, and relate three well-characterized examples of bistability to the molecular mechanisms that govern these processes, with a focus on positive feedback.