23 resultados para Cohomology of Groups
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo
Resumo:
In the present paper we generalize the concept of groups with triality and apply it to the theory of the Moufang, Bol and Bruck loops. Such generalizations allow us to reduce certain problems from the loop theory to problems in the theory of groups.
Resumo:
We analyse the dependence of the luminosity function (LF) of galaxies in groups on group dynamical state. We use the Gaussianity of the velocity distribution of galaxy members as a measurement of the dynamical equilibrium of groups identified in the Sloan Digital Sky Survey Data Release 7 by Zandivarez & Martinez. We apply the Anderson-Darling goodness-of-fit test to distinguish between groups according to whether they have Gaussian or non-Gaussian velocity distributions, i.e. whether they are relaxed or not. For these two subsamples, we compute the (0.1)r-band LF as a function of group virial mass and group total luminosity. For massive groups, , we find statistically significant differences between the LF of the two subsamples: the LFs of groups that have Gaussian velocity distributions have a brighter characteristic absolute magnitude (similar to 0.3 mag) and a steeper faint-end slope (similar to 0.25). We detect a similar effect when comparing the LF of bright [M-0.1r(group) - 5log(h) < -23.5] Gaussian and non-Gaussian groups. Our results indicate that, for massive/luminous groups, the dynamical state of the system is directly related to the luminosity of its galaxy members.
Resumo:
The purpose of this study was to retrospectively compare the treatment times of Class II division 1 malocclusion subjects treated with four first premolar extractions or a non- extraction protocol and fixed edgewise appliances. Eighty- four patients were selected and divided into two groups. Group 1, treated with four first premolar extractions, consisted of 48 patients (27 males and 21 females) with a mean age of 13.03 years and group 2, treated without extractions, consisted of 36 patients (18 males and 18 females) with a mean age of 13.13 years. Group 2 was subdivided into two subgroups, 2A consisting of 16 patients treated in one phase and 2B consisting of 20 patients treated in two phases. The initial and final Treatment Priority Index (TPI), initial ages, initial mandibular crowding, and treatment times of groups 1 and 2 were compared with t- tests. These variables were also compared between group 1 and the subgroups with analysis of variance followed by Tukey's tests. The treatment times for groups 1 and 2 and subgroups 2A and 2B were 2.36, 2.47, 2.25, and 2.64 years, respectively, which were not significantly different. Treatment times with non-extraction and four premolar extraction protocols are similar.
Resumo:
Let G = Z(pk) be a cyclic group of prime power order and let V and W be orthogonal representations of G with V-G = W-G = W-G = {0}. Let S(V) be the sphere of V and suppose f: S(V) -> W is a G-equivariant mapping. We give an estimate for the dimension of the set f(-1){0} in terms of V and W. This extends the Bourgin-Yang version of the Borsuk-Ulam theorem to this class of groups. Using this estimate, we also estimate the size of the G-coincidences set of a continuous map from S(V) into a real vector space W'.
Resumo:
Background. Acute normovolemic hemodilution (ANH) is an alternative to blood transfusion in surgeries involving blood loss. This experimental study was designed to evaluate whether pulse pressure variation (PPV) would be an adequate tool for monitoring changes in preload during ANH, as assessed by transesophageal echocardiography. Methods. Twenty-one anesthetized and mechanically ventilated pigs were randomized into three groups: CTL (control), HES (hemodilution with 6% hydroxyethyl starch at a 1:1 ratio) or NS (hemodilution with saline 0.9% at a 3:1 ratio). Hemodilution was performed in animals of groups NS and HES in two stages, with target hematocrits 22% and 15%, achieved at 30-minute intervals. After two hours, 50% of the blood volume withdrawn was transfused and animals were monitored for another hour. Statistical analysis was based on ANOVA for repeated measures followed by multiple comparison test (P<0.05). Pearson's correlations were performed between changes in left ventricular end-diastolic volume (LVEDV) and PPV, central venous pressure (CVP) and pulmonary artery occlusion pressure (PAOP). Results. Group NS received a significantly greater amount of fluids during ANH (NS, 900 +/- 168 mL vs. HES, 200 +/- 50 mL, P<0.05) and presented greater urine output (NS, 2643 +/- 1097mL vs. HES, 641 +/- 338mL, P<0.001). Significant decreases in LVEDV were observed in group NS from completion of ANH until transfusion. In group HES, only increases in LVEDV were observed, at the end of ANH and at transfusion. Such changes in LVEDV (Delta LVEDV) were better reflected by changes in PPV (Delta PPV, R=-0.62) than changes in CVP (Delta CVP R=0.32) or in PAOP (Delta PAOP, R=0.42, respectively). Conclusion. Changes in preload during ANH were detected by changes in PPV. Delta PPV was superior to Delta PAOP and Delta CVP to this end. (Minerva Anestesiol 2012;78:426-33)
Resumo:
We describe the structure of a free loop of rank n in the variety of automorphic Moufang loops as a subdirect product of a free group and a free commutative Moufang loop, both of rank n. In particular, the variety of automorphic Moufang loops is the join of the variety of groups and the variety of commutative Moufang loops.
Resumo:
Aim: To use published literature and experts' opinion to investigate the clinical meaning and magnitude of changes in the Quality of Life (QOL) of groups of patients measured with the European Organisation for the Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30). Methods: An innovative method combining systematic review of published studies, expert opinions and meta-analysis was used to estimate large, medium, and small mean changes over time for QLQ-C30 scores. Results: Nine hundred and eleven papers were identified, leading to 118 relevant papers. One thousand two hundred and thirty two mean changes in QOL over time were combined in the meta-analysis, with timescales ranging from four days to five years. Guidelines were produced for trivial, small, and medium size classes, for each subscale and for improving and declining scores separately. Estimates for improvements were smaller than respective estimates for declines. Conclusions: These guidelines can be used to aid sample size calculations and interpretation of mean changes over time from groups of patients. Observed mean changes in the QLQ-C30 scores are generally small in most clinical situations, possibly due to response shift. Careful consideration is needed when planning studies where QOL changes over time are of primary interest; the timing of follow up, sample attrition, direction of QOL changes, and subscales of primary interest are key considerations. (C) 2012 Elsevier Ltd. All rights reserved.
Resumo:
In this study we compared the microleakage of conventional glass ionomer cement (GIC) restorations following the use of different methods of root caries removal. In vitro root caries were induced in 75 human root dentin samples that were divided in five groups of 15 each according to the method used for caries removal: in group 1 spherical carbide burs at low speed were used, in group 2 a hand-held excavator was used, and in groups 3 to 5 an Er,Cr:YSGG laser was used at 2.25 W, 40.18 J/cm(2) (group 3), 2.50 W, 44.64 J/cm(2) (group 4) and 2.75 W, 49.11 J/cm(2) (group 5). The air/water cooling during irradiation was set to 55%/65% respectively. All cavities were filled with GIC. Five samples from each group were evaluated by scanning electron microscopy (SEM) and the other ten samples were thermocycled and submitted to a microleakage test. The data obtained were compared by ANOVA followed by Fisher's test (pa parts per thousand currency sign0.05). Group 4 showed the lowest microleakage index (56.65 6.30; p < 0.05). There were no significant differences among the other groups. On SEM images samples of groups 1 and 2 showed a more regular interface than the irradiated samples. Demineralized dentin below the restoration was observed, that was probably affected dentin. Group 4 showed the lowest microleakage values compared to the other experimental groups, so under the conditions of the present study the method that provided the lowest microleakage was the Er,Cr:YSGG laser with a power output of 2.5 W yielding an energy density of 44.64 J/cm(2).
Resumo:
Low-level laser irradiation (LLLI) and recombinant human bone morphogenetic protein type 2 (rhBMP-2) have been used to stimulate bone formation. LLLI stimulates proliferation of osteoblast precursor cells and cell differentiation and rhBMP-2 recruits osteoprogenitor cells to the bone healing area. This in vivo study evaluated the effects of LLLI and rhBMP-2 on the bone healing process in rats. Critical bone defects were created in the parietal bone in 42 animals, and the animals were divided into six treatment groups: (1) laser, (2) 7 mu g of rhBMP-2, (3) laser and 7 mu g of rhBMP-2, (4) 7 mu g of rhBMP-2/monoolein gel, (5) laser and 7 mu g rhBMP-2/monoolein gel, and (6) critical bone defect controls. A gallium-aluminum-arsenide diode laser was used (wavelength 780 nm, output power 60 mW, beam area 0.04 cm(2), irradiation time 80 s, energy density 120 J/cm(2), irradiance 1.5 W/cm(2)). After 15 days, the calvarial tissues were removed for histomorphometric analysis. Group 3 defects showed higher amounts of newly formed bone (37.89%) than the defects of all the other groups (P < 0.05). The amounts of new bone in defects of groups 1 and 4 were not significantly different from each other (24.00% and 24.75%, respectively), but were significantly different from the amounts in the other groups (P < 0.05). The amounts of new bone in the defects of groups 2 and 5 were not significantly different from each other (31.42% and 31.96%, respectively), but were significantly different from the amounts in the other groups (P < 0.05). Group 6 defects had 14.10% new bone formation, and this was significantly different from the amounts in the other groups (P < 0.05). It can be concluded that LLLI administered during surgery effectively accelerated healing of critical bone defects filled with pure rhBMP-2, achieving a better result than LLLI alone or the use of rhBMP-2 alone.
Resumo:
Abstract Background Large inequalities of mortality by most cancers in general, by mouth and pharynx cancer in particular, have been associated to behaviour and geopolitical factors. The assessment of socioeconomic covariates of cancer mortality may be relevant to a full comprehension of distal determinants of the disease, and to appraise opportune interventions. The objective of this study was to compare socioeconomic inequalities in male mortality by oral and pharyngeal cancer in two major cities of Europe and South America. Methods The official system of information on mortality provided data on deaths in each city; general censuses informed population data. Age-adjusted death rates by oral and pharyngeal cancer for men were independently assessed for neighbourhoods of Barcelona, Spain, and São Paulo, Brazil, from 1995 to 2003. Uniform methodological criteria instructed the comparative assessment of magnitude, trends and spatial distribution of mortality. General linear models assessed ecologic correlations between death rates and socioeconomic indices (unemployment, schooling levels and the human development index) at the inner-city area level. Results obtained for each city were subsequently compared. Results Mortality of men by oral and pharyngeal cancer ranked higher in Barcelona (9.45 yearly deaths per 100,000 male inhabitants) than in Spain and Europe as a whole; rates were on decrease. São Paulo presented a poorer profile, with higher magnitude (11.86) and stationary trend. The appraisal of ecologic correlations indicated an unequal and inequitably distributed burden of disease in both cities, with poorer areas tending to present higher mortality. Barcelona had a larger gradient of mortality than São Paulo, indicating a higher inequality of cancer deaths across its neighbourhoods. Conclusion The quantitative monitoring of inequalities in health may contribute to the formulation of redistributive policies aimed at the concurrent promotion of wellbeing and social justice. The assessment of groups experiencing a higher burden of disease can instruct health services to provide additional resources for expanding preventive actions and facilities aimed at early diagnosis, standardized treatments and rehabilitation.
Resumo:
Background: A common approach for time series gene expression data analysis includes the clustering of genes with similar expression patterns throughout time. Clustered gene expression profiles point to the joint contribution of groups of genes to a particular cellular process. However, since genes belong to intricate networks, other features, besides comparable expression patterns, should provide additional information for the identification of functionally similar genes. Results: In this study we perform gene clustering through the identification of Granger causality between and within sets of time series gene expression data. Granger causality is based on the idea that the cause of an event cannot come after its consequence. Conclusions: This kind of analysis can be used as a complementary approach for functional clustering, wherein genes would be clustered not solely based on their expression similarity but on their topological proximity built according to the intensity of Granger causality among them.
Resumo:
The in vitro schistosomicidal effects of the essential oil obtained from Tagetes erecta L. Asteraceae, leaves (TE-EO) collected in Brazil against Schistosoma mansoni worms are reported in this paper. The oil caused a significant decrease in the motor activity at 50 µg/mL as minimal concentration after 24 h. This oil also caused death of all the parasites and the separation of coupled pairs into individual male and female at 100 µg/mL after 24 h. The viability of adult worm groups treated with the TE-EO at 100 µg/mL was similar to that of groups treated with praziquantel (positive control). In addition, the oil promoted the inhibition of eggs development at all the tested concentrations. These data indicate that the TE-EO could be considered as a promising source for the development of new schistosomicidal agents.
Resumo:
This study investigates the species richness and abundance of Drosophila Fallén, 1823 attracted to dung and carrion baited pitfall traps in natural areas with heterogeneous habitats at the Sierra de Minas, Eastern Serranías, southeastern Uruguay. Collecting was carried out on a monthly basis (May 2002 through April 2003). Drosophilids accounted for 0.84% (n = 131) and 3.61% (n = 158) of the Diptera collected from dung (n = 15,630) and carrion (n = 4,382) pitfall traps, respectively. A total of 12 species were identified, 11 of which belong to the subgenus Drosophila (the richest) and one to the subgenus Sophophora Sturtevant, 1939. Over 90% of the Drosophila specimens collected belong to five species of the subgenus Drosophila, namely D. gaucha Jaeger & Salzano, 1953, D. immigrans Sturtevant, 1921, D. mediovittata Frota-Pessoa, 1954, D. aff. nappae Vilela, Valente & Basso-da-Silva, 2004, and D. ornatifrons Duda, 1927. Drosophila cardini Sturtevant, 1916 is recorded for the first time from Uruguay. Drosophila abundance and species richness in the four habitats sampled in the Uruguayan Eastern Serranías, namely woodlands sierra, riparian forest, pine plantation and grazing grassland, were considered to be a function of habitat conservation. Diversity indices were low in all habitats. Different habitats supported particular coprophilous and necrophilous Drosophila species. The woodland sierra represents the most preserved habitat, and contributed with the highest species richness observed. Drosophila ornatifrons was the dominant species, with a restricted habitat distribution. On the other hand, grazed grassland, an environment modified by livestock management, had the lowest species richness: only a few specimens of D. repleta Wollaston, 1858. Regarding species composition, significant differences were found in some pairwise comparisons of groups of Drosophila species that included D. ornatifrons. Fly attraction to dung can be exploited as an alternative and/or complementary collecting method in ecological studies of Drosophila assemblages in natural areas.
Resumo:
In a previous paper, we connected the phenomenological noncommutative inflation of Alexander, Brandenberger and Magueijo [ Phys. Rev. D 67 081301 (2003)] and Koh and Brandenberger [ J. Cosmol. Astropart Phys. 2007 21 ()] with the formal representation theory of groups and algebras and analyzed minimal conditions that the deformed dispersion relation should satisfy in order to lead to a successful inflation. In that paper, we showed that elementary tools of algebra allow a group-like procedure in which even Hopf algebras (roughly the symmetries of noncommutative spaces) could lead to the equation of state of inflationary radiation. Nevertheless, in this paper, we show that there exists a conceptual problem with the kind of representation that leads to the fundamental equations of the model. The problem comes from an incompatibility between one of the minimal conditions for successful inflation (the momentum of individual photons being bounded from above) and the Fock-space structure of the representation which leads to the fundamental inflationary equations of state. We show that the Fock structure, although mathematically allowed, would lead to problems with the overall consistency of physics, like leading to a problematic scattering theory, for example. We suggest replacing the Fock space by one of two possible structures that we propose. One of them relates to the general theory of Hopf algebras (here explained at an elementary level) while the other is based on a representation theorem of von Neumann algebras (a generalization of the Clebsch-Gordan coefficients), a proposal already suggested by us to take into account interactions in the inflationary equation of state.
Resumo:
The purpose of this study was to analyze the influence of lactation and dry period in the constituents of lipid and glucose metabolism of buffaloes. One hundred forty-seven samples of serum and plasma were collected between November 2009 and July 2010, from properties raising Murrah, Mediterranean and crossbred buffaloes, located in the State of Sao Paulo, Brazil. Biochemical analysis was obtained by determining the contents of serum cholesterol, triglycerides, beta-hydroxybutyrate (β-HBO), non-esterified fatty acids (NEFA) and plasma glucose. Values for arithmetic mean and standard error mean were calculated using the SAS procedure, version 9.2. Tests for normality of residuals and homogeneity of variances were performed using the SAS Guide Data Analysis. Data were analyzed by ANOVA using the SAS procedure Glimmix. The group information (Lactation), Farm and Age were used in the statistical models. Means of groups were compared using Least Square Means (LSMeans) of SAS, where significant difference was observed at P ≤ 0.05. It was possible to conclude that buffaloes during peak lactation need to metabolize body reserves to supplement the lower amounts of bloodstream lipids, when they remain in negative energy balance. In the dry period, there were significant changes in the lipid profile, characterized by decrease of nutritional requirements, with consequent improvement in the general conditions of the animals.