44 research outputs found

    Shared Memory Pipelined Parareal

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    For the parallel-in-time integration method Parareal, pipelining can be used to hide some of the cost of the serial correction step and improve its efficiency. The paper introduces an OpenMP implementation of pipelined Parareal and compares it to a standard MPI-based variant. Both versions yield almost identical runtimes, but, depending on the compiler, the OpenMP variant consumes about 7% less energy and has a significantly smaller memory footprint. However, its higher implementation complexity might make it difficult to use in legacy codes and in combination with spatial parallelisation

    Mental Health Diagnoses and Utilization of VA Non-Mental Health Medical Services Among Returning Iraq and Afghanistan Veterans

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    Over 35% of returned Iraq and Afghanistan veterans in VA care have received mental health diagnoses; the most prevalent is post-traumatic stress disorder (PTSD). Little is known about these patients’ use of non-mental health medical services and the impact of mental disorders on utilization. To compare utilization across three groups of Iraq and Afghanistan veterans: those without mental disorders, those with mental disorders other than PTSD, and those with PTSD. National, descriptive study of 249,440 veterans newly utilizing VA healthcare between October 7, 2001 and March 31, 2007, followed until March 31, 2008. We used ICD9-CM diagnostic codes to classify mental health status. We compared utilization of outpatient non-mental health services, primary care, medical subspecialty, ancillary services, laboratory tests/diagnostic procedures, emergency services, and hospitalizations during veterans’ first year in VA care. Results were adjusted for demographics and military service and VA facility characteristics. Veterans with mental disorders had 42–146% greater utilization than those without mental disorders, depending on the service category (all P < 0.001). Those with PTSD had the highest utilization in all categories: 71–170% greater utilization than those without mental disorders (all P < 0.001). In adjusted analyses, compared with veterans without mental disorders, those with mental disorders other than PTSD had 55% higher utilization of all non-mental health outpatient services; those with PTSD had 91% higher utilization. Female sex and lower rank were also independently associated with greater utilization. Veterans with mental health diagnoses, particularly PTSD, utilize significantly more VA non-mental health medical services. As more veterans return home, we must ensure resources are allocated to meet their outpatient, inpatient, and emergency needs

    Posttraumatic Stress Disorder Prevalence and Risk of Recurrence in Acute Coronary Syndrome Patients: A Meta-analytic Review

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    BACKGROUND:Acute coronary syndromes (ACS; myocardial infarction or unstable angina) can induce posttraumatic stress disorder (PTSD), and ACS-induced PTSD may increase patients' risk for subsequent cardiac events and mortality. OBJECTIVE:To determine the prevalence of PTSD induced by ACS and to quantify the association between ACS-induced PTSD and adverse clinical outcomes using systematic review and meta-analysis. DATA SOURCES:Articles were identified by searching Ovid MEDLINE, PsycINFO, and Scopus, and through manual search of reference lists. METHODOLOGY/PRINCIPAL FINDINGS:Observational cohort studies that assessed PTSD with specific reference to an ACS event at least 1 month prior. We extracted estimates of the prevalence of ACS-induced PTSD and associations with clinical outcomes, as well as study characteristics. We identified 56 potentially relevant articles, 24 of which met our criteria (N = 2383). Meta-analysis yielded an aggregated prevalence estimate of 12% (95% confidence interval [CI], 9%-16%) for clinically significant symptoms of ACS-induced PTSD in a random effects model. Individual study prevalence estimates varied widely (0%-32%), with significant heterogeneity in estimates explained by the use of a screening instrument (prevalence estimate was 16% [95% CI, 13%-20%] in 16 studies) vs a clinical diagnostic interview (prevalence estimate was 4% [95% CI, 3%-5%] in 8 studies). The aggregated point estimate for the magnitude of the relationship between ACS-induced PTSD and clinical outcomes (ie, mortality and/or ACS recurrence) across the 3 studies that met our criteria (N = 609) suggested a doubling of risk (risk ratio, 2.00; 95% CI, 1.69-2.37) in ACS patients with clinically significant PTSD symptoms relative to patients without PTSD symptoms. CONCLUSIONS/SIGNIFICANCE:This meta-analysis suggests that clinically significant PTSD symptoms induced by ACS are moderately prevalent and are associated with increased risk for recurrent cardiac events and mortality. Further tests of the association of ACS-induced PTSD and clinical outcomes are needed

    Head-and-neck paragangliomas are associated with sleep-related complaints, especially in the presence of carotid body tumors

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    Item does not contain fulltextOBJECTIVES: The carotid body functions as a chemoreceptor. We hypothesized that head-and-neck paragangliomas (HNP) may disturb the function of these peripheral chemoreceptors and play a role in sleep-disordered breathing. DESIGN: This is a case-control study. SETTING: This study was conducted in a tertiary referral center. PARTICIPANTS AND MAIN OUTCOME MEASURES: We assessed fatigue, sleep, and exercise capacity in 74 HNP patients using three questionnaires (Epworth Sleepiness Scale, St. George Respiratory Questionnaire, and a standard clinical sleep assessment questionnaire). Outcomes were compared to those of age- and sex-matched controls. RESULTS AND CONCLUSIONS: Activity, disturbance of psychosocial function, and total score were worse compared to controls (15.4 +/- 18.5 vs. 7.2 +/- 9.9, P = 0.007; 5.3 +/- 10.5 vs. 1.2 +/- 2.6, P = 0.008; and 10.4 +/- 12.9 vs. 5.0 +/- 4.8, P = 0.006, respectively). Patients reported more daytime fatigue, concentration difficulties, and depression (51% vs. 24%, P = 0.006; 31% vs. 10%, P = 0.010; and 19% vs. 2%, P = 0.012). Waking up was reported to be less refreshing in HNP patients (53% vs. 73%, P = 0.038). Dysphonia was a predictor of symptoms, activity, disturbance of psychosocial function, and total scores. Remarkably, the presence of a carotid body tumor was an independent predictor of increased daytime sleepiness (beta = 0.287, P = 0.029). In conclusion, patients with HNP have remarkable sleep-related complaints. Especially the presence of carotid body tumors appears to be associated with increased daytime somnolence.1 juni 201

    Behaviour of Solitary Adult Scandinavian Brown Bears (Ursus arctos) when Approached by Humans on Foot

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    Successful management has brought the Scandinavian brown bear (Ursus arctos L.) back from the brink of extinction, but as the population grows and expands the probability of bear-human encounters increases. More people express concerns about spending time in the forest, because of the possibility of encountering bears, and acceptance for the bear is decreasing. In this context, reliable information about the bear's normal behaviour during bear-human encounters is important. Here we describe the behaviour of brown bears when encountering humans on foot. During 2006–2009, we approached 30 adult (21 females, 9 males) GPS-collared bears 169 times during midday, using 1-minute positioning before, during and after the approach. Observer movements were registered with a handheld GPS. The approaches started 869±348 m from the bears, with the wind towards the bear when passing it at approximately 50 m. The bears were detected in 15% of the approaches, and none of the bears displayed any aggressive behaviour. Most bears (80%) left the initial site during the approach, going away from the observers, whereas some remained at the initial site after being approached (20%). Young bears left more often than older bears, possibly due to differences in experience, but the difference between ages decreased during the berry season compared to the pre-berry season. The flight initiation distance was longer for active bears (115±94 m) than passive bears (69±47 m), and was further affected by horizontal vegetation cover and the bear's age. Our findings show that bears try to avoid confrontations with humans on foot, and support the conclusions of earlier studies that the Scandinavian brown bear is normally not aggressive during encounters with humans

    Dose finding and O6-alkylguanine-DNA alkyltransferase study of cisplatin combined with temozolomide in paediatric solid malignancies

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    Cisplatin may have additive activity with temozolomide due to ablation of the DNA repair protein O6-alkylguanine-DNA alkyltransferase (MGMT). This phase I/II study determined recommended combination doses using the Continual Reassessment Method, toxicities and antitumour activity in paediatric patients, and evaluated MGMT in peripheral blood mononuclear cells (PBMCs) in order to correlate with haematological toxicity. In total, 39 patients with refractory or recurrent solid tumours (median age ∼13 years; 14 pretreated with high-dose chemotherapy, craniospinal irradiation, or having bone marrow involvement) were treated with cisplatin, followed the next day by oral temozolomide for 5 days every 4 weeks at dose levels 80 mg m−2/150 mg m−2 day−1, 80/200, and 100/200, respectively. A total of 38 patients receiving 113 cycles (median 2, range 1–7) were evaluable for toxicity. Dose-limiting toxicity was haematological in all but one case. Treatment-related toxicities were thrombocytopenia, neutropenia, nausea-vomiting, asthenia. Hearing loss was experienced in five patients with prior irradiation to the brain stem or posterior fossa. Partial responses were observed in two malignant glioma, one brain stem glioma, and two neuroblastoma. Median MGMT activity in PBMCs decreased after 5 days of temozolomide treatment: low MGMT activity correlated with increased severity of thrombocytopenia. Cisplatin–temozolomide combinations are well tolerated without additional toxicity to single-agent treatments; the recommended phase II dosage is 80 mg m−2 cisplatin and 150 mg m−2 × 5 temozolomide in heavily treated, and 200 mg m−2 × 5 temozolomide in less-heavily pretreated children
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