Home About us Contact
|
Home About us Contact | ||
|
|
||
Important Reduction (important + reduction)
Selected AbstractsIncreasing data reuse of sparse algebra codes on simultaneous multithreading architecturesCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 15 2009J. C. Pichel Abstract In this paper the problem of the locality of sparse algebra codes on simultaneous multithreading (SMT) architectures is studied. In these kind of architectures many hardware structures are dynamically shared among the running threads. This puts a lot of stress on the memory hierarchy, and a poor locality, both inter-thread and intra-thread, may become a major bottleneck in the performance of a code. This behavior is even more pronounced when the code is irregular, which is the case of sparse matrix ones. Therefore, techniques that increase the locality of irregular codes on SMT architectures are important to achieve high performance. This paper proposes a data reordering technique specially tuned for these kind of architectures and codes. It is based on a locality model developed by the authors in previous works. The technique has been tested, first, using a simulator of a SMT architecture, and subsequently, on a real architecture as Intel's Hyper-Threading. Important reductions in the number of cache misses have been achieved, even when the number of running threads grows. When applying the locality improvement technique, we also decrease the total execution time and improve the scalability of the code. Copyright © 2009 John Wiley & Sons, Ltd. [source] Continuous subcutaneous insulin infusion (CSII) 30 years later: still the best option for insulin therapyDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 2 2009Daniela Bruttomesso Abstract Thirty years after its introduction, the use of continuous subcutaneous insulin infusion (CSII) keeps increasing, especially among children and adolescents. The technique, when used properly, is safe and effective. Compared with traditional NPH-based multiple daily injections (MDI), CSII provides a small but clinically important reduction of HbA1c levels, diminishes blood glucose variability, decreases severe hypoglycaemic episodes and offers a better way to cope with the dawn phenomenon. Insulin analogues have improved the treatment of diabetes, eroding part of the place previously occupied by CSII, but CSII still remains the first option for patients experiencing severe hypoglycaemic episodes, high HbA1c values or marked glucose variability while being treated with optimized MDI. Furthermore CSII is better than MDI considering the effects on quality of life and the possibility to adjust insulin administration according to physical activity or food intake. CSII may be limited by cost. Present estimates suggest that CSII may be cost-effective just for patients experiencing a marked improvement in HbA1c or a decrease in severe hypoglycaemic episodes, but the effects on quality of life are difficult to measure. CSII does not merely imply wearing an external device; it requires a multidisciplinary team, intensive patient education and continuous follow up. Copyright © 2009 John Wiley & Sons, Ltd. [source] Seismic response of slopes subjected to incident SV wave by an improved boundary element approachINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 10 2007Behrouz Gatmiri Abstract In this paper, an improved boundary element approach for 2D elastodynamics in time-domain is presented. This approach consists in the truncation of time integrations, based on the rapid decrease of the fundamental solutions with time. It is shown that an important reduction of the computation time as well as the storage requirement can be achieved. Moreover, for half-plane problems, the size of boundary element (BE) meshes and the computation time can be significantly reduced. The proposed approach is used to study the seismic response of slopes subjected to incident SV waves. It is found that large amplifications take place on the upper surface close to the slope, while attenuations are produced on the lower surface. The results also show that surface motions become very complex when the incident wavelength is comparable with the size of the slope or when the slope is steep. Copyright © 2006 John Wiley & Sons, Ltd. [source] Friction reduction in rolling bearing by using polymer additives,LUBRICATION SCIENCE, Issue 8 2009Maria Bercea Abstract The friction torque on the outer ring of a tapered roller bearing has been experimentally measured for a mineral oil (base oil), as well as for samples of the base oil additived with low-density polyethylene. The data show an important reduction of friction by introducing the polymer into the base oil due to the film formed by the adsorption of macromolecular coils on the solid surface. The effectiveness of macromolecular additive contribution to friction behaviour is described in terms of polymer efficiency, which shows maximum values at low polymer concentrations. Copyright © 2009 John Wiley & Sons, Ltd. [source] Keratinocytes Control the Pheo/Eumelanin Ratio in Cultured Normal Human MelanocytesPIGMENT CELL & MELANOMA RESEARCH, Issue 6 2002Christine Duval The pheo/eumelanin ratio of cultured normal human melanocytes is distinct from the ratio observed for the same cells in vivo where they are in close contact with keratinocytes. To study the possible involvement of keratinocytes in the control of melanogenesis, we compared quantitatively and qualitatively the melanin production in melanocyte mono-cultures, in melanocyte,keratinocyte co-cultures and in pigmented reconstructed epidermis. Pheomelanin and eumelanin contents were assessed by high-performance liquid chromatography with electrochemical and fluorometric detection of their specific degradation products and revealed striking differences in the presence of keratinocytes. In the absence of keratinocytes (melanocyte mono-cultures), we observed a very limited eumelanin production and a very high pheomelanin synthesis. The pheo/eumelanin ratio in mono-cultures could be slightly influenced by changing the composition of the culture medium, however, the very strong imbalance in favor of pheomelanin remained unchanged. An induction of eumelanin synthesis accompanied by an important reduction of pheomelanin formation was only observed in the presence of keratinocytes. The pheo/eumelanin ratio in melanocyte mono-culture dropped from 1043 down to about 25 in the presence of keratinocytes (co-cultures). The same observations were made when the melanocytes were integrated into a reconstructed human epidermis. Interestingly, under co-culture conditions resulting in only a partial contact between melanocytes and keratinocytes, the reduction of the pheo/eumelanin ratio were less pronounced. From these results we conclude that keratinocytes play an important role in the melanin production, affecting the melanogenic pathways. [source] ORIGINAL RESEARCH,PEYRONIE'S DISEASE: Use of Penile Extender Device in the Treatment of Penile Curvature as a Result of Peyronie's Disease.THE JOURNAL OF SEXUAL MEDICINE, Issue 2 2009Results of a Phase II Prospective Study ABSTRACT Introduction., Pilot experiences have suggested that tension forces exerted by a penile extender may reduce penile curvature as a result of Peyronie's disease. Aim., To test this hypothesis in a Phase II study using a commonly marketed brand of penile extender. Methods., Peyronie's disease patients with a curvature not exceeding 50° with mild or no erectile dysfunction (ED) were eligible. Fifteen patients were required to test the efficacy of the device assuming an effect size of >0.8, consistent with an "important" reduction in penile curvature. Changes in penile length over baseline and erectile function (EF) domain scores of the International Index of Erectile Function (IIEF) constituted secondary end points. Main Outcome Measures., Patients were counselled on the use of the penile extender for at least 5 hours per day for 6 months. Photographic pictures of the erect penis and measurements were carried out at baseline, at 1, 3, 6, and 12 months (end of study). The IIEF-EF domain scores were administered at baseline and at the end of study. Treatment satisfaction was assessed at end of study using a nonvalidated institutional 5-item questionnaire. Results., Penile curvature decreased from an average of 31° to 27° at 6 months without reaching the effect size (P = 0.056). Mean stretched and flaccid penile length increased by 1.3 and 0.83 cm, respectively at 6 months. Results were maintained at 12 months. Overall treatment results were subjectively scored as acceptable in spite of curvature improvements, which varied from "no change" to "mild improvement." Conclusions., In our study, the use of a penile extender device provided only minimal improvements in penile curvature but a reasonable level of patient satisfaction, probably attributable to increased penile length. The selection of patients with a stabilized disease, a penile curvature not exceeding 50°, and no severe ED may have led to outcomes underestimating the potential efficacy of the treatment. Gontero P, Di Marco M, Giubilei G, Bartoletti R, Pappagallo G, Tizzani A, and Mondaini N. Use of penile extender device in the treatment of penile curvature as a result of Peyronie's disease. Results of a phase II prospective study. J Sex Med 2009;6:558,566. [source] LIBERALIZATION OF EUROPEAN TELECOMMUNICATIONS: SECTORAL DYNAMICS AND STRUCTURAL MUTATIONSANNALS OF PUBLIC AND COOPERATIVE ECONOMICS, Issue 3 2007Philippe BANCE ABSTRACT,:,This contribution intends to draw up an assessment of structural changes in the telecommunications sector impelled by the European policy of liberalization. Deep transformations with contrasted results have occurred. A strong differentiation in offer of services and a considerable fall in cost appears. After a strong growth, however, investment sharply decreased with the financial crisis. Employment has become a variable of adjustment for companies subjected to strong risks due to the economic situation. Lastly, the assertion of the universal service of telecommunications is accompanied by an important reduction of public service missions. [source] Case-Mix Adjustment of the CAHPS® Hospital SurveyHEALTH SERVICES RESEARCH, Issue 6p2 2005A. James O'Malley Objectives: To develop a model for case-mix adjustment of Consumer Assessment of Healthcare Providers and Systems (CAHPS®) Hospital survey responses, and to assess the impact of adjustment on comparisons of hospital quality. Data Sources: Survey of 19,720 patients discharged from 132 hospitals. Methods: We analyzed CAHPS Hospital survey data to assess the extent to which patient characteristics predict patient ratings ("predictive power") and the heterogeneity of the characteristics across hospitals. We combined the measures to estimate the impact of each predictor ("impact factor") and selected high impact variables for adjusting ratings from the CAHPS Hospital survey. Principle Findings: The most important case-mix variables are: hospital service (surgery, obstetric, medical), age, race (non-Hispanic black), education, general health status (GHS), speaking Spanish at home, having a circulatory disorder, and interactions of each of these variables with service. Adjustment for GHS and education affected scores in each of the three services, while age and being non-Hispanic black had important impacts for those receiving surgery or medical services. Circulatory disorder, Spanish language, and Hispanic affected scores for those treated on surgery, obstetrics, and medical services, respectively. Of the 20 medical conditions we tested, only circulatory problems had an important impact within any of the services. Results were consistent for the overall ratings of nurse, doctor, and hospital. Although the overall impact of case-mix adjustment is modest, the rankings of some hospitals may be substantially affected. Conclusions: Case-mix adjustment has a small impact on hospital ratings, but can lead to important reductions in the bias in comparisons between hospitals. [source] | |||||||||||||