47 resultados para Shearing layers of change
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)
Resumo:
Stages of change assess individual motivation for lifestyle changes, contributing to the development of more effective intervention strategies. The objective of the present study was to identify factors associated with stages of change for lower intake of red meat and higher intake of vegetables in a cross-sectional analysis of 578 Japanese-Brazilians aged 30-90 years. In adjusted logistic regression models, the odds ratios for women (OR = 1.89; 95%CI: 1.154; 3.103) and physically active individuals (OR = 1.00; 95%CI: 1.000; 1.001) were positively associated with stage of "action" for the higher intake of vegetables. Inverse associations were observed between central obesity (OR = 0.5; 95%CI: 0.351; 0.887) and highest tertile of red meat intake (OR = 0.50; 95%CI: 0.302; 0.817), as well as a positive association between age (OR = 1.04; 95%CI: 1.020; 1.070) and the stage of "action" to the lower intake of meat were verified. Motivation for Japanese-Brazilians to change their food intake was linked to lifestyle. Stage of change is an important factor in mediating food intake behavior change.
Resumo:
In 2002, the Brazilian Ministry of Education approved the official curricular guidelines for undergraduate courses in Brazil to be adopted by the nation's 188 dental schools. In 2005-06, the Brazilian Dental Education Association (BDEA) promoted workshops in forty-eight of the schools to verify the degree of transformation of the curriculum based on these guidelines. Among the areas analyzed were course philosophy (variables were v1: knowledge production based on the needs of the Brazilian Public Health System [BPHS]; v2: health determinants; and v3: postgraduate studies and permanent education); pedagogical skills (v4: curricular structure; v5: changes in pedagogic and didactic skills; and v6: course program orientation); and dental practice scenarios (v7: diversity of the scenarios for training/learning; v8: academic health care centers opened to the BPHS; and v9: participation of students in health care delivery for the population). The subjects consisted of faculty members (n=711), students (n=228), and employees (n=14). The results showed an incipient degree of curriculum transformation. The degree of innovation was statistically different depending on the type of university (public or private) for variables I, 2, 4, 5, 6, and 7. Private schools reported a higher level of innovation than public institutions. Resistance to transforming the dental curriculum according to the official guidelines may be linked to an ideological conception that supports the private practice model, continues to have faculty members direct all classroom activities, and prevents students from developing an understanding of professional practice as targeted towards the oral health needs of all segments of society.
Resumo:
In this work a new method for crosslinking ultra-thin films with potential applications in sensor systems is proposed. The films were produced by layer-by-layer (LbL) assembly using a conducting polymer, poly(o-ethoxyaniline) (POEA), alternated with a thermosetting resin, novolac-type phenolformaldehyde (PF), crosslinked by a simple thermal treatment. The PF resin served as both alternating and crosslinking agents. The films were characterized by Fourier transform infrared (FTIR) and ultraviolet-visible (UV-Vis) spectroscopy, thermogravimetry (TG), desorption, doping/dedoping cycling and electrical measurements. The results showed that film architecture and crosslinking degree can be controlled by the conditions used for film deposition (number of bilayers, polymer concentration, pH, and deposition time), and crosslinking time. Moreover, this approach offers several advantages such as fast curing time and low cost, indicating that these films can be used to produce sensors with improved stability.
Resumo:
For the past half a century, Latin American scholars have been pointing toward the emergence of new social actors as agents of social and political democratization. The first wave of actors was characterized by the emergence of novel agents-mainly, new popular movements-of social transformation. At first, the second wave, epitomized by nongovernmental organizations (NGOs), was celebrated as the upsurge of a new civil society, but later on, it was the target of harsh criticism. The literature often portrays this development in Latin American civil society as a displacement trend of actors of the first wave by the second wave-""NGOization""-""and even denounces new civil society as rootless, depoliticized, and functional to retrenchment. Thus, supposedly, NGOization encumbers social change. The authors argue that NGOization diagnosis is a flawed depiction of change within civil society. Rather than NGOization related to the depoliticization and neoliberalization of civil society, in Mexico City and Sao Paulo, there has been modernization of organizational ecologies, changes in the functional status of civil society, and interestingly, specialization aimed at shaping public agenda. The authors argue that such specialization, instead of encumbering social change, brings about different repertoires of strategies and skills purposively developed for influencing policy and politics. Their argument relies on comparative systematic evidence. Through network analysis, they examine the organizational ecology of civil society in Mexico City and Sao Paulo.
Resumo:
PURPOSE. To evaluate and compare rates of change in neuro-retinal rim area (RA) and retinal nerve fiber layer thickness (RNFLT) measurements in glaucoma patients, those with suspected glaucoma, and normal subjects observed over time. METHODS. In this observational cohort study, patients recruited from two longitudinal studies (Diagnostic Innovations in Glaucoma Study-DIGS and African Descent and Evaluation Study-ADAGES) were observed with standard achromatic perimetry (SAP), optic disc stereophotographs, confocal scanning laser ophthalmoscopy (HRT-3; Heidelberg Engineering, Heidelberg, Germany), and scanning laser polarimetry (GDx-VCC; Carl Zeiss Meditec, Inc., Dublin, CA). Glaucoma progression was determined by the Guided Progression Analysis software for standard automated perimetry [SAP] and by masked assessment of serial optic disc stereophotographs by expert graders. Random-coefficients models were used to evaluate rates of change in average RNFLT and global RA measurements and their relationship with glaucoma progression. RESULTS. At baseline, 194 (31%) eyes were glaucomatous, 347 (55%) had suspected glaucoma, and 88 (14%) were normal. Forty-six (9%) eyes showed progression by SAP and/or stereophotographs, during an average follow-up of 3.3 (+/-0.7) years. The average rate of decline for RNFLT measurements was significantly higher in the progressing group than in the non-progressing group (-0.65 vs. -0.11 mu m/y, respectively; P < 0.001), whereas RA decline was not significantly different between these groups (-0.0058 vs. -0.0073 mm(2)/y, respectively; P = 0.727). The areas under the receiver operating characteristic (ROC) curves used to discriminate progressing versus nonprogressing eyes were 0.811 and 0.507 for the rates of change in the RNFLT and RA, respectively (P < 0.001). CONCLUSIONS. The ability to discriminate eyes with progressing glaucoma by SAP and/or stereophotographs from stable eyes was significantly greater for RNFLT than for RA measurements. (Invest Ophthalmol Vis Sci. 2010;51:3531-3539) DOI: 10.1167/iovs.09-4350
Resumo:
Objective. To evaluate the perception of eating practices and the stages of change among adolescents. Methods. Cross-sectional study involving a representative sample of 390 adolescents from 11 public schools in the city of Piracicaba, Brazil, in 2004. Food consumption was identified by a food frequency questionnaire and the perception of eating practices evaluation was conducted by comparing food consumption and individual classification of healthy aspects of the diet. The participants were classified within stages of change by means of a specific algorithm. A reclassification within new stages of change was proposed to identify adolescents with similar characteristics regarding food consumption and perception. Results. Low consumption of fruit and vegetables and high consumption of sweets and fats were identified. More than 44% of the adolescents had a mistaken perception of their diet. A significant relationship between the stages of change and food consumption was observed. The reclassification among stages of change, through including the pseudo-maintenance and non-reflective action stages was necessary, considering the high proportion of adolescents who erroneously classified their diets as healthy. Conclusion. Classification of the adolescents into stages of change, together with consumption and perception data, enabled identification of groups at risk, in accordance with their inadequate dietary habits and non-recognition of such habits. (C) 2009 Elsevier Inc. All rights reserved.
Resumo:
A study of the potential role of aerosols in modifying clouds and precipitation is presented using a numerical atmospheric model. Measurements of cloud condensation nuclei (CCN) and cloud size distribution properties taken in the southwestern Amazon region during the transition from dry to wet seasons were used as guidelines to define the microphysical parameters for the simulations. Numerical simulations were carried out using the Brazilian Development on Regional Atmospheric Modeling System, and the results presented considerable sensitivity to changes in these parameters. High CCN concentrations, typical of polluted days, were found to result in increases or decreases in total precipitation, depending on the level of pollution used as a reference, showing a complexity that parallels the aerosol-precipitation interaction. Our results show that on the grids evaluated, higher CCN concentrations reduced low-to-moderate rainfall rates and increased high rainfall rates. The principal consequence of the increased pollution was a change from a warm to a cold rain process, which affected the maximum and overall mean accumulated precipitation. Under polluted conditions, cloud cover diminished, allowing greater amounts of solar radiation to reach the surface. Aerosol absorption of radiation in the lower layers of the atmosphere delayed convective evolution but produced higher maximum rainfall rates due to increased instability. In addition, the intensity of the surface sensible heat flux, as well as that of the latent heat flux, was reduced by the lower temperature difference between surface and air, producing greater energy stores at the surface.
Resumo:
In this paper, we consider some non-homogeneous Poisson models to estimate the probability that an air quality standard is exceeded a given number of times in a time interval of interest. We assume that the number of exceedances occurs according to a non-homogeneous Poisson process (NHPP). This Poisson process has rate function lambda(t), t >= 0, which depends on some parameters that must be estimated. We take into account two cases of rate functions: the Weibull and the Goel-Okumoto. We consider models with and without change-points. When the presence of change-points is assumed, we may have the presence of either one, two or three change-points, depending of the data set. The parameters of the rate functions are estimated using a Gibbs sampling algorithm. Results are applied to ozone data provided by the Mexico City monitoring network. In a first instance, we assume that there are no change-points present. Depending on the adjustment of the model, we assume the presence of either one, two or three change-points. Copyright (C) 2009 John Wiley & Sons, Ltd.
Resumo:
Ellipsometry was used to investigate the influence of ionic strength (I) and pH on the adsorption of bovine serum albumin (BSA) or beta-lactoglobulin (BLG) onto preabsorbed layers of two polycations: poly(diallyldimethylammonium chloride) (PDADMAC) or poly(4-vinylpyridine bromide) quaternized with linear aliphatic chains of two (QPVP-C2) or five (QPVP-C5) carbons. Comparisons among results for the three polycations reveal hydrophobic interactions, while comparisons between BSA and BLG-proteins of very similar isoelectric points (pI)-indicate the importance of protein charge anisotropy. At pH close to pI, the ionic strength dependence of the adsorbed amount of protein (Gamma) displayed maxima in the range 10 < I < 25 mM corresponding to Debye lengths close to the protein radii. Visualization of protein charge by Delphi suggested that these ionic strength conditions corresponded to suppression of long-range repulsion between polycations and protein positive domains, without diminution of short-range attraction between polycation segments and locally negative protein domains, in a manner similar to the behavior of PE-protein complexes in solution.(1-4) This description was consistent with the disappearance of the maxima at pH either above or below pI. In the former case, Gamma values decrease exponentially with I(1/2), due to screening of attractions, while in the latter case adsorption of both proteins decreased at low I due to strong repulsion. Close to or below pI both proteins adsorbed more strongly onto QPVP-C5 than onto QPVP-C2 or PDADMAC due to hydrophobic interactions with the longer alkyl group. Above pI, the adsorption was more pronounced with PDADMAC because these chains may assume more loosely bound layers due to lower linear charge density.
Resumo:
The lianas observed in this study, Abuta convexa (Vell.) Diels, Abuta imene (Mart.) Eichler, and Chondrodendron platiphyllum (A. St.-Hil.) Miers, all have successive cambia in their stems. The terminology applied to stem histology in species with successive cambia is as diverse as the interpretations of the origins of this cambial variant. Therefore, this study specifically investigates the origin of successive cambia through a developmental analysis of the above-mentioned species, including an analysis of the terminology used to describe this cambial variation. For the first time, we have identified several developmental stages giving rise to the origins of successive cambia in this family. First, the pericycle originates in 1-3 layers of conjunctive tissue. After the differentiation of the first ring, the conjunctive tissue undergoes new divisions, developing approximately 10 rows of parenchyma cells. In the middle portion, a layer of sclereids is formed, again subdividing the conjunctive tissue into two parts: internal and external. New cambia originate in the internal part, from which new secondary vascular strands will originate, giving rise to the second successive vascular ring of the stem. The external part remains parenchymatous during the installation of the second ring and will undergo new periclinal division, repeating the entire process. New cambia will originate from the neoformed strands, which will form only rays. In the literature, successive cambia are formed by a meristem called "diffuse lateral meristem."However, based on the species of Menispermaceae studied in this report, it is demonstrated that the diffuse lateral meristem is the pericycle itself.
Resumo:
The thermal conductivity and mechanical strength of gypsum and gypsum-cellulose plates made from commercial plaster by a new process have been measured. The gypsum parts made by the new process, 'novogesso', have high mechanical strength and low porosity. The gypsum strength derives from both the high aspect ratio of the gypsum crystals and the strong adhesion among them by nano-flat layers of confined water, which behaves as supercooled water. Another contribution to the strength comes from the nano-flatness of the lateral surfaces of the gypsum single crystals. The bending and compression strengths, σB and σc, of gypsum plates prepared by this new technique can be as high as 30 and 100 MPa, respectively. The way gypsum plates have been assembled as well as their low thermal conductivity allowed for the construction of a low-cost experimental house with thermal and acoustic comfort.
Resumo:
Background: We have previously demonstrated that four members of the family of small leucine-rich-proteoglycans (SLRPs) of the extracellular matrix (ECM), named decorin, biglycan, lumican and fibromodulin, are deeply remodeled in mouse uterine tissues along the estrous cycle and early pregnancy. It is known that the combined action of estrogen (E2) and progesterone (P4) orchestrates the estrous cycle and prepares the endometrium for pregnancy, modulating synthesis, deposition and degradation of various molecules. Indeed, we showed that versican, another proteoglycan of the ECM, is under hormonal control in the uterine tissues. Methods: E2 and/or medroxiprogesterone acetate (MPA) were used to demonstrate, by real time PCR and immunoperoxidase staining, respectively, their effects on mRNA expression and protein deposition of these SLRPs, in the uterine tissues. Results: Decorin and lumican were constitutively expressed and deposited in the ECM in the absence of the ovarian hormones, whereas deposition of biglycan and fibromodulin were abolished from the uterine ECM in the non-treated group. Interestingly, ovariectomy promoted an increase in decorin, lumican and fibromodulin mRNA levels, while biglycan mRNA conspicuously decreased. Hormone replacement with E2 and/or MPA differentially modulates their expression and deposition. Conclusions: The patterns of expression of these SLRPs in the uterine tissues were found to be hormone-dependent and uterine compartment-related. These results reinforce the existence of subpopulations of endometrial fibroblasts, localized into distinct functional uterine compartments, resembling the organization into basal and functional layers of the human endometrium.
Resumo:
The structure of thin films composed of a multilayer of PbTe nanocrystals embedded in SiO(2), named as PbTe(SiO(2)), between homogeneous layers of amorphous SiO(2) deposited on a single-crystal Si( 111) substrate was studied by grazing-incidence small-angle X-ray scattering (GISAXS) as a function of PbTe content. PbTe(SiO(2))/SiO(2) multilayers were produced by alternately applying plasma-enhanced chemical vapour deposition and pulsed laser deposition techniques. From the analysis of the experimental GISAXS patterns, the average radius and radius dispersion of PbTe nanocrystals were determined. With increasing deposition dose the size of the PbTe nanocrystals progressively increases while their number density decreases. Analysis of the GISAXS intensity profiles along the normal to the sample surface allowed the determination of the period parameter of the layers and a structure parameter that characterizes the disorder in the distances between PbTe layers. (C) 2010 International Union of Crystallography Printed in Singapore - all rights reserved
Resumo:
Shallow subsurface layers of gold nanoclusters were formed in polymethylmethacrylate (PMMA) polymer by very low energy (49 eV) gold ion implantation. The ion implantation process was modeled by computer simulation and accurately predicted the layer depth and width. Transmission electron microscopy (TEM) was used to image the buried layer and individual nanoclusters; the layer width was similar to 6-8 nm and the cluster diameter was similar to 5-6 nm. Surface plasmon resonance (SPR) absorption effects were observed by UV-visible spectroscopy. The TEM and SPR results were related to prior measurements of electrical conductivity of Au-doped PMMA, and excellent consistency was found with a model of electrical conductivity in which either at low implantation dose the individual nanoclusters are separated and do not physically touch each other, or at higher implantation dose the nanoclusters touch each other to form a random resistor network (percolation model). (C) 2009 American Vacuum Society. [DOI: 10.1116/1.3231449]
Resumo:
The structure of a complex between hydrated DNA and a non-cationic lipid is studied, including its phase diagram. The complex is spontaneously formed by adding DNA fragments (ca. 150 base pairs in length) to non-cationic lipids and water. The self-assembly process often leads to highly ordered structures. The structures were studied by combining X-ray scattering, fluorescence and polarized microscopy, as well as freeze-fracture experiments with transmission electron microscopy. We observe a significant increase of the smectic order as DNA is incorporated into the water layers of the lamellar host phase, and stabilization of single phase domains for large amounts of DNA. The effect of confinement on DNA ordering is investigated by varying the water content, following three dilution lines. A rich polymorphism is found, ranging from weakly correlated DNA-DNA in-plane organizations to highly ordered structures, where transmembrane correlations lead to the formation of columnar rectangular and columnar hexagonal superlattices of nucleotides embedded between lipid lamellae. From these observations, we suggest that addition of DNA to the lamellar phase significantly restricts membrane fluctuations above a certain concentration and helps the formation of the lipoplex. The alteration of membrane steric interactions, together with the appearance of interfacial interactions between membranes and DNA molecules may be a relevant mechanism for the emergence of highly ordered structures in the concentrated regime.