Towards an Achievable Performance for the Loop Nests

Numerous code optimization techniques, including loop nest optimizations, have been developed over the last four decades. Loop optimization techniques transform loop nests to improve the performance of the code on a target architecture, including exposing parallelism. Finding and evaluating an optimal, semantic-preserving sequence of transformations is a complex problem. The sequence is guided using heuristics and/or analytical models and there is no way of knowing how close it gets to optimal performance or if there is any headroom for improvement. This paper makes two contributions. First, it uses a comparative analysis of loop optimizations/transformations across multiple compilers to determine how much headroom may exist for each compiler. And second, it presents an approach to characterize the loop nests based on their hardware performance counter values and a Machine Learning approach that predicts which compiler will generate the fastest code for a loop nest. The prediction is made for both auto-vectorized, serial compilation and for auto-parallelization. The results show that the headroom for state-of-the-art compilers ranges from 1.10x to 1.42x for the serial code and from 1.30x to 1.71x for the auto-parallelized code. These results are based on the Machine Learning predictions.Comment: Accepted at the 31st International Workshop on Languages and Compilers for Parallel Computing (LCPC 2018

Brazilian Doctor's Perspective On The Second Opinion Strategy Before A C-section

Objective: To describe the opinion of doctors who participated in the Latin American Study on Cesarean section in Brazil regarding the second opinion strategy when faced with the decision of performing a C-section. Methods: Seventy-two doctors from the hospitals where the study took place (where the second opinion was routinely sought) and 70 from the control group answered a pre-tested self-administered structured questionnaire. Descriptive tables were prepared based on the frequency of relevant variables on opinion of physicians regarding: effectiveness of the application of the second opinion strategy; on whether they would recommend implementation of this strategy and reasons for not recommending it in private institutions; feasibility of the strategy implementation and reasons for not considering this implementation feasible in private institutions. Results: Half of the doctors from the intervention hospitals (50%) and about two thirds of those in the control group (65%) evaluated the second opinion as being or having the potential of being effective/very effective in their institutions. The great majority of those interviewed from both intervention and control hospitals considered this strategy feasible in public (87% and 95% respectively) but not in private hospitals (64% and 70% respectively), mainly because in the latter the doctors would not accept interference from a colleague in their decision-making process. Conclusion: Although the second opinion strategy was perceived as effective in reducing C-section rates, doctors did not regard it feasible outside the public health system in Brazil. © 2006 Faculdade de Saúde Pública da Universidade de Sao Paulo.402233239Althabe, F., Belizan, J.M., Villar, J., Alexander, S., Bergel, E., Ramos, S., Mandatory second opinion to reduce rates of unnecessary caesarean sections in Latin America: A cluster randomised controlled trial (2004) Lancet, 363 (9425), pp. 1934-1940Belizan, J., Althabe, F., Barros, F.C., Alexander, S., Rates and implications of caesarean sections in Latin America: Ecological study (1999) BMJ, 319 (7222), pp. 1397-1402Chacham, A.S., Perpétuo, I.H.O., The incidence of caesarean deliveries in Belo Horizonte, Brazil: Social and economic determinants (1998) Reprod Health Matters, 6 (11), pp. 115-121Faúndes, A., Perpétuo, I.H.O., Cesárea por conveniência e a ética médica (2002) Ser Médico, 5 (19), pp. 32-34Faúndes, A., Pádua, K.S., Osis, M.J.D., Cecatti, J.G., Sousa, M.H., Opiniāo de mulheres e médicos brasileiros sobre a preferência pela via de parto (2004) Rev Saúde Pública, 38 (4), pp. 488-494Hopkins, K., Are brazilian women really choosing to deliver by cesarean? (2000) Soc Sci Med, 51 (5), pp. 725-740Mello e Souza, C., C-sections as ideal births: The cultural constructions of beneficence and patients' rights in Brazil (1994) Camb Q Healthc Ethics, 3 (3), pp. 358-366Moraes, M.S., Goldenberg, P., Cesáreas: Um perfil epidêmico (2001) Cad Saúde Pública, 17 (3), pp. 509-519Murray, S., Relation between private health insurance and high rates of caesarean section in Chile: Qualitative and quantitative study (2000) BMJ, 321 (7275), pp. 1501-1505Myers, S.A., Gleicher, N., A successful program to lower cesarean-section rates (1988) N Engl J Med, 319 (23), pp. 1511-1516(1998), 1. , Organización Panamericana de la Salud - OPAS. La salud en las Americas. Washington (DC)Osis, M.J.D., Pádua, K.S., Duarte, G.A., Souza, T.R., Faúndes, A., The opinion of brazilian women regarding vaginal labor and cesarean section (2001) Int J Gynaecol Obstet, 75 (SUPPL. 1), pp. S59-S66Penna, L., Arulkumaran, S., Cesarean section for non-medical reasons (2003) Int J Gynaecol Obstet, 82 (3), pp. 399-409Potter, J.E., Berquó, E., Perpétuo, I.H.O., Leal, O.F., Hopkins, K., Souza, M.R., Unwanted caesarean sections among public and private patients in Brazil: Prospective study (2001) BMJ, 323 (7322), pp. 1155-1158Rattner, D., Sobre a hipótese de estabilizaçāo das taxas de cesárea do estado de São Paulo, Brasil (1996) Rev Saúde Pública, 30 (1), pp. 19-33Schenker, J.G., Cain, J.M., FIGO committee report: FIGO committee for the ethical aspects of human reproduction and women's health (1999) Int J Gynaecol Obstet, 64 (3), pp. 317-322Sloan, N.L., Pinto, E., Calle, A., Langer, A., Winikoff, B., Fassihian, G., Reduction of cesarean delivery rate in Ecuador (2000) Int J Gynaecol Obstet, 69 (3), pp. 229-236Walker, R., Turnbull, D., Wilkinson, C., Strategies to address global cesarean section rates: A review of the evidence (2002) Birth, 29 (1), pp. 28-39Wolfe, S., Unnecessary cesarean sections: Curing a national epidemic (1994) Public Citiz Health Res Group, 10, pp. 1-

Occurrence and Abundance of Phosphatase-Producing Bacteria in Mangrove Ecosystem

The study detailed the isolation and characterization of phosphatase producing bacteria (PPB) from rhizospheric, pneumatophoric and bulk sediments of Avicennia marina along Mumbai coast, India and also estimated alkaline phosphatase activity in sediment in addition to the Phosphatase enzymatic activity of isolates. The inorganic-organic nature of phosphorus was also examined. About, 42 PPB were isolated and identified from the sediment samples. 16S rDNA sequence revealed that all the isolates belong to the genus Bacillus except the one which belong to Geobacillus in the environment and B. anthracis str. Ames showed the phosphatase-producing activity of 84.11±0.01 µg p-NP released per 1×108 cfu in 72 hrs. The isolates, B. cereus strain APT23 and B. thuringiensis strain INRS4 showed the next best phosphatase activity. It was observed that PPB was very much abundant in A. marina mangroves. The pneumatophoric sediment showed significantly higher number of PPB with higher alkaline phosphatase activity, inorganic P and low organic P than those of other sediment types indicating that pneumatophoric region of A. marina harbours favourably the phosphatase-producers than the rhizospheric or bulk sediments and forms the first reference worldwide depicting this relationship. The isolates that showed higher phosphatase-producing potentials can be explored for using as phosphatic bio-fertilizer to enhance the agricultural, aquacultural and mangrove productivity on a larger scale

The effect of age, sex and a firm-textured surface on postural control.

In previous studies, the influence of plantar sensation has been examined using various textured surfaces with different stiffness materials to assess static balance. This study investigated the effects of a Firm Textured Surface (FTS) along with age and sex-related influences on postural control under different visual conditions. Forty subjects (20 elderly, 10 males, mean age 68.30, 10 females, mean age 68.00, and 20 young people, 10 males, mean age 25.45, 10 females, mean age 27.30) participated in this study maintained a quiet standing on FTS, foam and firm surfaces with eyes open and closed. The center of pressure displacement (CoPDISP), CoP velocity (CoPVEL), and sway velocity of the CoP in anteroposterior (AP) and mediolateral (ML) direction (VA/P and VM/L) were measured. FTS was associated with lower postural sway measures in both the groups with eyes open and closed. However, the foam surface showed the worst results in all postural parameters under all experimental conditions. Separate four-way ANOVAs were applied to each dependent variable. The main effects of surface (p < 0.0001), vision (p < 0.0001) and age (p < 0.0001 for CoPDISP, CoPVEL and VA/P; p = 0.0003 for VM/L) were significant in each of the four fitted models. Sex was never significant, either as a main effect or an interaction with other experimental factors. Eyes open were able to reduce the negative effects of the foam surfaces but without vision the proprioceptive sensory system cues of the body state become more important for maintaining balance. A good stimulation with rigid texture should be considered as relief to reduce the physiological-related decline of afferent information with ag

Trunk and Lower Extremity Kinematics During Stair Descent in Women With or Without Patellofemoral Pain

Context: There is limited evidence indicating the contribution of trunk kinematics to patellofemoral pain (PFP). A better understanding of the interaction between trunk and lower extremity kinematics in this population may provide new avenues for interventions to treat PFP. Objective: To compare trunk and lower extremity kinematics between participants with PFP and healthy controls during a stair-descent task. Design: Cross-sectional study. Setting: Research laboratory. Patients or Other Participants: Twenty women with PFP (age = 22.2 +/- 3.1 years, height = 164.5 +/- 9.2 cm, mass = 63.5 +/- 13.6 kg) and 20 healthy women (age = 21.0 +/- 2.6 years, height = 164.5 +/- 7.1 cm, mass = 63.8 +/- 12.7 kg). Intervention(s): Kinematics were recorded as participants performed stair descent at a controlled velocity. Main Outcome Measure(s): Three-dimensional joint displacement of the trunk, hip, and knee during the stance phase of stair descent for the affected leg was measured using a 7-camera infrared optical motion-capture system. Pretest and posttest pain were assessed using a visual analogue scale. Kinematic differences between groups were determined using independent-samples t tests. A 2 3 2 mixed-model analysis of variance (group = PFP, control; time = pretest, posttest) was used to compare knee pain. Results: We observed greater knee internal-rotation displacement for the PFP group (12.8 degrees +/- 7.2 degrees) as compared with the control group (8.9 degrees +/- 4.4 degrees). No other between-groups differences were observed for the trunk, hip, or other knee variables. Conclusions: We observed no difference in trunk kinematics between groups but did note differences in knee internalrotation displacement. These findings contribute to the current knowledge of altered movement in those with PFP and provide direction for exercise interventions

Idealização do Masculino e do Feminino a Partir dos Processos de Crimes Passionais na Cidade de Vitória (1890-1930)

Este trabalho é o resultado de uma investigação do processo histórico sobre o masculino e o feminino, na cidade de Vitória e entorno, durante a Primeira República Brasileira (1890-1930), no Estado do Espírito Santo. Foram analisadas as idealizações dos papéis sociais do homem e da mulher, por meio de processos judiciais de crimes passionais, contemplando-se entendimentos de juízes, depoimentos de envolvidos e de testemunhas. Os resultados apontam que a violência de gênero e a sua legitimação têm como importantes contribuintes a natureza da relação de poder e de reafirmação que marcavam a estrutura hierárquica capixaba. A partir de um elenco de princípios considerados positivos e negativos, desenharam-se representações sociais de condutas aceitáveis e nãoaceitáveis que orientavam as práticas sociais dos sujeitos. A Justiça, em alguns processos, apresentou-se imparcial, relativizando a sua conduta quando de sentenças que poderiam ferir valores considerados cruciais ao tempo. Por fim, buscou-se contribuir ao resgate da história local, contextualizando-a no âmbito da nacional; destacando-se a importância da cidade de Vitória como núcleo político, econômico e cultural do Estado

Geodesics around line defects in elastic solids

Topological defects in solids, usually described by complicated boundary conditions in elastic theory, may be described more simply as sources of a gravity- like deformation field in the geometric approach of Katanaev and Volovich. This way, the deformation field is described by non-Euclidean metric that incorporates the boundary imposed by the defects. A possible way of gaining some insight into the motion of particles in a medium with topological defects (e.g., electrons in a dislocated metal) is to look at the geodesics of the medium around the defect. In this work, we find the exact solution for the geodesic equation for elastic medium with a generic line defect, the dispiration, that can either be a screw dislocation or a wedge disclination for particular choices of its parameters.Comment: 10 pages, Latex, 4 figures, accepted for publication in Phys. Lett.

Generalised Hong-Ou-Mandel Experiments with Bosons and Fermions

The Hong-Ou-Mandel (HOM) dip plays an important role in recent linear optics experiments. It is crucial for quantum computing with photons and can be used to characterise the quality of single photon sources and linear optics setups. In this paper, we consider generalised HOM experiments with $N$ bosons or fermions passing simultaneously through a symmetric Bell multiport beam splitter. It is shown that for even numbers of bosons, the HOM dip occurs naturally in the coincidence detection in the output ports. In contrast, fermions always leave the setup separately exhibiting perfect coincidence detection. Our results can be used to verify or employ the quantum statistics of particles experimentally.Comment: 11 pages, 2 figures, more references adde