Modelling speedup (n) greater than n

A simple model of parallel computation which is capable of explaining speedups greater than n on n processors is presented. Necessary and sufficient conditions for these exceptional speedups are derived from the model. Several of the contradictory previous results relating to parallel speedup are resolved by using the model     

Assessment of atomistic coarse-graining methods

This paper reviews classical theories of coarse-graining and gives a short introduction to representative coarse-grained atomistic models that were developed based on structure reduction, an assumption of homogenous deformation, and field representation. The applicability and limitations of these coarse-grained models are analyzed on the basis of their theoretical frameworks as well as the coarse-graining methods they employ.     

A critical analysis of on-scene helicopter transport on survival in a statewide trauma system

BACKGROUND: Recently, questions have been raised regarding the effectiveness of helicopters in trauma care. We conducted a retrospective study to evaluate the effect of on-scene helicopter transport on survival after trauma in a statewide trauma system. METHODS: Data were obtained from a statewide trauma registry of 162,730 patients treated at 28 accredited trauma centers. Patients transported from the scene by helicopter (15,938) were compared with those transported by ground with advanced life support (ALS) (6,473). Interhospital transfers and transports without ALS were excluded. Statistical analysis was performed using one-way analysis of variance and logistic regression. RESULTS: Patients transported by helicopter were significantly (p < 0.01) younger, were more seriously injured, and had lower blood pressure. They were also more likely to be male and to have systolic blood pressure < 90 mm Hg. Logistic regression analysis revealed that when adjusting for other risk factors, transportation by helicopter did not affect the estimated odds of survival. CONCLUSION: A reappraisal of the cost-effectiveness of helicopter triage and transport criteria, when access to ground ALS squads is available, may be warranted.     

Using health status surveys in medical consultations

The goal of this research was to identify patients' preferences for physician inquiry into various aspects of health status and to examine whether the preconsultation availability of health status data (collected from the SF-36 Health Status Questionnaire) influenced the physician's conduct during the consultation. Results from 58 prenatal patient visits yielded the following findings. First, patients expressed strong preferences for physicians to ask about the patient's perceptions of health in general and about physical dimensions of health status such as pain, vitality, and role limitations due to physical functioning. Patients also were more satisfied when doctors were perceived as having asked about these issues. Second, patients varied considerably in their preferences for physician inquiries into psychosocial issues such as social functioning, mental health, and role limitations due to emotional problems. Approximately half the patients wanted these matters discussed, whereas the remainder either did not care or preferred that doctors not ask about these topics. Third, the preconsultation availability of health status information had little effect on the degree to which physicians asked about the patient's health-related quality of life. Clinical implications are discussed.     

The arabidopsis ACT7 actin gene is expressed in rapidly developing tissues and responds to several external stimuli

ACT7 encodes one of the six distinct and ancient subclasses of actin protein in the complex Arabidopsis actin gene family. We determined the sequence and structure of the Arabidopsis thaliana ACT7 actin gene and investigated its tissue-specific expression and regulation. The ACT7 mRNA levels varied by 128-fold among several different tissues and organs. The highest levels of aCT7 mRNA were found in rapidly expanding vegetative organs, the lowest in pollen. A translational fusion with the 5' end of ACT 7 (1.9 kb) joined to the beta-glucuronidase reporter gene was strongly and preferentially expressed in all young, developing vegetative tissues of transgenic Arabidopsis plants. ACT7 was the only Arabidopsis actin gene strongly expressed in the hypocotyl and seed coat. Although no beta-glucuronidase expression was seen in developing ovules or immature seeds, strong expression was seen in dry seeds and immediately after imbibition in the entire seedling. ACT7 was the only Arabidopsis actin gene to respond strongly to auxin, other hormone treatments, light regime, and wounding, and may be the primary actin gene responding to external stimuli. The ACT7 promoter sequence contains a remarkable number of motifs with sequence similarity to putative phytohormone response elements.     

A nonpharmacologic sleep protocol for hospitalized older patients

OBJECTIVES: To evaluate the feasibility of and adherence to a nonpharmacologic sleep protocol targeted to nurses for acutely ill older patients and to test the effectiveness of the protocol on enhancing sleep and reducing sedative-hypnotic drug (SHD) use. DESIGN: Prospective cohort study. SETTING: A 34-bed general medical unit in a university-affiliated teaching hospital. PARTICIPANTS: A total of 175 consecutive admissions aged 70 years or older. INTERVENTION: A nonpharmacologic sleep protocol consisting of a back rub, warm drink, and relaxation tapes was administered by nursing personnel to patients who complained of difficulty initiating sleep or who requested a SHD. After 1 hour, if the patient still requested it, the nurse administered the SHD. MEASUREMENTS: The main outcomes of sleep quality and SHD use were measured by patient interview and chart abstraction. Feasibility and adherence to the protocol were tracked daily by patient and nurse interviews and chart abstraction. RESULTS: A cohort of 111 patients, mean age 79.3 (+/- 6.4), 68% women, received the sleep protocol. Patients required the protocol for a mean of 4.9 days per patient, totalling 539 patients-days. The overall adherence rate was 400/539 (74%) patient-days. The rate of complete nonadherence was 139/539 (26%), with reasons for nonadherence including nurse nonadherence in 30 (6%), patient refusal in 104 (19%), and medical contraindications in five (1%). The quality of sleep correlated strongly with the number of parts of the protocol received, suggesting a dose-response relationship, with the highest correlation for receiving two to three parts (p = .64, P < 0.001). The sleep protocol was successful in reducing SHD use from the baseline preintervention rate of 51/94 (54%) to 34/111 (31%) (P < .002). The sleep protocol had a stronger association with quality of sleep (p = .75, P = .001) than did SHDs (p = .07, P = .45). However, chronic SHD users were more likely to refuse the protocol than nonusers (64% vs 41%, P < .03) and received SHDs 4.5 times more often than nonusers (67% vs 15%, P = .001). CONCLUSION: The nonpharmacologic sleep protocol provides a feasible, effective, and nontoxic alternative to SHDs to promote sleep in older hospitalized patients. Use of the protocol can substantially decrease use of SHDs.     

Start/Pat: a parallel-programming toolkit

The authors address the question of how to use existing sequential Fortran code on multiprocessors. Their answer is Start/Pat, an interactive toolkit that automates the parallelization of sequential Fortran as it teaches the programmer how to exploit and understand parallel structures and architectures. The Start/Pat prototype has been installed at several user sites. The authors discuss the choice of PCF Fortran, the toolkit components, and the features of Pat and Start