929 resultados para talk shows


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Several numerical methods for boundary value problems use integral and differential operational matrices, expressed in polynomial bases in a Hilbert space of functions. This work presents a sequence of matrix operations allowing a direct computation of operational matrices for polynomial bases, orthogonal or not, starting with any previously known reference matrix. Furthermore, it shows how to obtain the reference matrix for a chosen polynomial base. The results presented here can be applied not only for integration and differentiation, but also for any linear operation.

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Synchronization plays an important role in telecommunication systems, integrated circuits, and automation systems. Formerly, the masterslave synchronization strategy was used in the great majority of cases due to its reliability and simplicity. Recently, with the wireless networks development, and with the increase of the operation frequency of integrated circuits, the decentralized clock distribution strategies are gaining importance. Consequently, fully connected clock distribution systems with nodes composed of phase-locked loops (PLLs) appear as a convenient engineering solution. In this work, the stability of the synchronous state of these networks is studied in two relevant situations: when the node filters are first-order lag-lead low-pass or when the node filters are second-order low-pass. For first-order filters, the synchronous state of the network shows to be stable for any number of nodes. For second-order filter, there is a superior limit for the number of nodes, depending on the PLL parameters. Copyright (C) 2009 Atila Madureira Bueno et al.

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The synthesis of [Ru(NO(2)) L(bpy)(2)](+) (bpy = 2,2'-bipyridine and L = pyridine (py) and pyrazine (pz)) can be accomplished by addition of [Ru(NO) L(bpy) 2](PF(6))(3) to aqueous solutions of physiological pH. The electrochemical processes of [Ru(NO2) L(bpy) 2]+ in aqueous solution were studied by cyclic voltammetry and differential pulse voltammetry. The anodic scan shows a peak around 1.00 V vs. Ag/AgCl attributed to the oxidation process centered on the metal ion. However, in the cathodic scan a second peak around-0.60 V vs. Ag/AgCl was observed and attributed to the reduction process centered on the nitrite ligand. The controlled reduction potential electrolysis at-0.80 V vs. Ag/AgCl shows NO release characteristics as judged by NO measurement with a NO-sensor. This assumption was confirmed by ESI/MS(+) and spectroelectrochemical experiment where cis-[Ru(bpy)(2)L(H(2)O)](2+) was obtained as a product of the reduction of cis-[Ru(II)(NO(2)) L(bpy)(2)](+). The vasorelaxation observed in denuded aortic rings pre-contracted with 0.1 mu mol L(-1) phenylephrine responded with relaxation in the presence of cis-[RuII(NO2) L(bpy) 2]+. The potential of rat aorta cells to metabolize cis-[RuII(NO(2)) L(bpy)(2)](+) was also followed by confocal analysis. The obtained results suggest that NO release happens by reduction of cis-[RuII(NO(2)) L(bpy)(2)](+) inside the cell. The maximum vasorelaxation was achieved with 1 x 10(-5) mol L(-1) of cis-[RuII(NO(2)) L(bpy)(2)](+) complex.

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This paper reflects the current situation surrounding indigenous teacher education by means of the construction of a dialogue among three educators, two of them non-indigenous educators involved with indigenous school education and one indigenous educator committed to the education of his people. Teacher education, situated in a socio-cultural way, is the center of attention in this paper. ""Listening"" as a way of talking with the ""other"" is one of the theoretical focuses of this exercise between teacher educators and teachers, which uses dialogue as a means to increase awareness. In the dialogic process mentione, it was possible to realize how rich a dynamic between educators from different cultural contexts can be. The desire of the indigenous educator and his/her people to contribute their ideas to the construction of the indigenous school became evident. This shows the great challenge for non-indigenous educators seeking to contribute to the organization of the school education of distinct indigenous nations.

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Wild felids and canids are usually the main predators in the food chains where they dwell and are almost invisible to behavior and ecology researchers. Due to their grooming behavior, they tend to swallow shed hair, which shows up in the feces. DNA found in hair shafts can be used in molecular studies that can unravel, for instance, genetic variability, reproductive mode and family structure, and in some species, it is even possible to estimate migration and dispersion rates in given populations. First, however, DNA must be extracted from hair. We extracted successfully and dependably hair shaft DNA from eight wild Brazilian felids, ocelot, margay, oncilla, Geoffroy's cat, pampas cat, jaguarundi, puma, and jaguar, as well as the domestic cat and from three wild Brazilian canids, maned wolf, crab-eating fox, and hoary fox, as well as the domestic dog. Hair samples came mostly from feces collected at the Sao Paulo Zoo and were also gathered from non-sedated pet or from recently dead wild animals and were also collected from museum specimens. Fractions of hair samples were stained before DNA extraction, while most samples were not. Our extraction protocol is based on a feather DNA extraction technique, based in the phenol: chloroform: isoamyl alcohol general method, with proteinase K as digestive enzyme.

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Cuticle renewal is a complex biological process that depends on the cross talk between hormone levels and gene expression. This study characterized the expression of two genes encoding cuticle proteins sharing the four conserved amino acid blocks of the Tweedle family, AmelTwdl1 and AmelTwdl2, and a gene encoding a cuticle peroxidase containing the Animal haem peroxidase domain, Ampxd, in the honey bee. Gene sequencing and annotation validated the formerly predicted tweedle genes, and revealed a novel gene, Ampxd, in the honey bee genome. Expression of these genes was studied in the context of the ecdysteroid-coordinated pupal-to-adult molt, and in different tissues. Higher transcript levels were detected in the integument after the ecdysteroid peak that induces apolysis, coinciding with the synthesis and deposition of the adult exoskeleton and its early differentiation. The effect of this hormone was confirmed in vivo by tying a ligature between the thorax and abdomen of early pupae to prevent the abdominal integument from coming in contact with ecdysteroids released from the prothoracic gland. This procedure impaired the natural increase in transcript levels in the abdominal integument. Both tweedle genes were expressed at higher levels in the empty gut than in the thoracic integument and trachea of pharate adults. In contrast, Ampxd transcripts were found in higher levels in the thoracic integument and trachea than in the gut. Together, the data strongly suggest that these three genes play roles in ecdysteroid-dependent exoskeleton construction and differentiation and also point to a possible role for the two tweedle genes in the formation of the cuticle (peritrophic membrane) that internally lines the gut.

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Over time the city has been involved in constant changes related with its diversity, processes and internal structure. As urban reality, the concepts of urban geography as a discipline shows a metamorphosis based on the agitation of urban reality. This investigation aims to update the geographical literature, without extreme simplifications and including as much perspectives as possible. Pierre George gives and extraordinary example about the extension of that knowledge, abruptly become obsolete.

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Among the numerous problems that are common to the Latin-American metropolises, such as the deep socio-spatial segregation, the impressive territorial fragmentation and the real estate valorisation that overvalues some territories, whilst it depreciates others, we have chosen to focus on the management of the metropolitan regions. That question clearly indicates that due to the great current changes of the economical restructuring - a process that strengthened the capitalist logic of social development - the traditional form of thinking urban planning has found its limits. Consequently, this issue of metropolitan management shows the need to look for new ways of metropolitan administration that can answer to the The main metropolitan regions of South America: Buenos Aires, Sao Paulo and Santiago form our references to characterize the recent changes from a territorial point of view on the one hand; and relative to the new determinations of the metropolis on the other hand. This leads us to discuss the challenges that metropolitan management face in a scenario of governability fragmentation.

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This paper emphasizes the important changes in Brazilian foreign policy after Luiz Inacio Lula da Silva took tip the power in 2002. The paper defends the idea that it is not possible to argue that there were deep changes in comparison to Cardoso's administration. However, evidence shows that new things are happening as regards the design of a more active and clear foreign action line which led to institutional changes and to more incisive multilateral paths. This results both from the political profile of the direct operators of foreign policy and the aims of lite presidential diplomacy, The hypothesis dealt with on this paper consists on the fact that Lula's administration has not fully broken with the old administration practices, however the aims of global and regional integration are being plotted more clearly and with a higher degree of activism. This becomes clear in three aspects of the Brazilian foreign policy: the institutional framework, the practice of multilateralism and the foreign policy towards the South, the three topics analyzed in this paper.

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The objective of this manuscript is to discuss the existing barriers for the dissemination of medical guidelines, and to present strategies that facilitate the adaptation of the recommendations into clinical practice. The literature shows that it usually takes several years until new scientific evidence is adopted in current practice, even when there is obvious impact in patients' morbidity and mortality. There are some examples where more than thirty years have elapsed since the first case reports about the use of a effective therapy were published until its utilization became routine. That is the case of fibrinolysis for the treatment of acute myocardial infarction. Some of the main barriers for the implementation of new recommendations are: the lack of knowledge of a new guideline, personal resistance to changes, uncertainty about the efficacy of the proposed recommendation, fear of potential side-effects, difficulties in remembering the recommendations, inexistence of institutional policies reinforcing the recommendation and even economical restrains. In order to overcome these barriers a strategy that involves a program with multiple tools is always the best. That must include the implementation of easy-to-use algorithms, continuous medical education materials and lectures, electronic or paper alerts, tools to facilitate evaluation and prescription, and periodic audits to show results to the practitioners involved in the process. It is also fundamental that the medical societies involved with the specific medical issue support the program for its scientific and ethical soundness. The creation of multidisciplinary committees in each institution and the inclusion of opinion leaders that have pro-active and lasting attitudes are the key-points for the program's success. In this manuscript we use as an example the implementation of a guideline for venous thromboembolism prophylaxis, but the concepts described here can be easily applied to any other guideline. Therefore, these concepts could be very useful for institutions and services that aim at quality improvement of patient care. Changes in current medical practice recommended by guidelines may take some time. However, if there is a broader participation of opinion leaders and the use of several tools listed here, they surely have a greater probability of reaching the main objectives: improvement in provided medical care and patient safety.

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Background: The MASS IV-DM Trial is a large project from a single institution, the Heart Institute (InCor), University of Sao Paulo Medical School, Brazil to study ventricular function and coronary arteries in patients with type 2 diabetes mellitus. Methods/Design: The study will enroll 600 patients with type 2 diabetes who have angiographically normal ventricular function and coronary arteries. The goal of the MASS IV-DM Trial is to achieve a long-term evaluation of the development of coronary atherosclerosis by using angiograms and coronary-artery calcium scan by electron-beam computed tomography at baseline and after 5 years of follow-up. In addition, the incidence of major cardiovascular events, the dysfunction of various organs involved in this disease, particularly microalbuminuria and renal function, will be analyzed through clinical evaluation. In addition, an effort will be made to investigate in depth the presence of major cardiovascular risk factors, especially the biochemical profile, metabolic syndrome inflammatory activity, oxidative stress, endothelial function, prothrombotic factors, and profibrinolytic and platelet activity. An evaluation will be made of the polymorphism as a determinant of disease and its possible role in the genesis of micro- and macrovascular damage. Discussion: The MASS IV-DM trial is designed to include diabetic patients with clinically suspected myocardial ischemia in whom conventional angiography shows angiographically normal coronary arteries. The result of extensive investigation including angiographic follow-up by several methods, vascular reactivity, pro-thrombotic mechanisms, genetic and biochemical studies may facilitate the understanding of so-called micro- and macrovascular disease of DM.

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Background: Mucin immunoexpression in adenocarcinoma arising in Barrett's esophagus (BE) may indicate the carcinogenesis pathway. The aim of this study was to evaluate resected specimens of adenocarcinoma in BE for the pattern of mucins and to correlate to the histologic classification. Methods: Specimens were retrospectively collected from thirteen patients who underwent esophageal resection due to adenocarcinoma in BE. Sections were scored for the grade of intestinal metaplasia. The tissues were examined by immunohistochemistry for MUC2 and MUC5AC antibodies. Results: Eleven patients were men. The mean age was 61 years old (varied from 40 to 75 years old). The tumor size had a mean of 4.7 +/- 2.3 cm, and the extension of BE had a mean of 7.7 +/- 1.5 cm. Specialized epithelium with intestinal metaplasia was present in all adjacent mucosas. Immunohistochemistry for MUC2 showed immunoreactivity in goblet cells, while MUC5AC was extensively expressed in the columnar gastric cells, localizing to the surface epithelium and extending to a variable degree into the glandular structures in BE. Tumors were classified according to the mucins in gastric type in 7/13 (MUC5AC positive) and intestinal type in 4/13 (MUC2 positive). Two tumors did not express MUC2 or MUC5AC proteins. The pattern of mucin predominantly expressed in the adjacent epithelium was associated to the mucin expression profile in the tumors, p = 0.047. Conclusion: Barrett's esophagus adenocarcinoma shows either gastric or intestinal type pattern of mucin expression. The two types of tumors developed in Barrett's esophagus may reflect the original cell type involved in the malignant transformation.

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We analyzed lesser diameter and distribution of fiber types in different skeletal muscles from female Wistar rats using a histoenzymology Myofibrillar Adenosine Tri-phosphatase (mATPase) method. Fragments from muscles were frozen and processed by mATPase in different pH. Adult and weanling rat soleus muscles presented a predominance of type I fibers and larger fiber diameters. In the plantar muscle in adult rats, the type IIB fibers demonstrated greater lesser diameter while in the weanling animals, types I and IIB fibers were larger. The plantar muscle of animals of both ages was composed predominantly of the type IID fibers. The type IID fibers were observed in similar amounts in the lateral gastrocnemius and the medial gastrocnemius muscles. Type IIB fibers showed predominance and presented higher size in comparison with other types in the EDL muscle. The present study shows that data on fiber type distribution and fiber lesser diameter obtained in adult animals cannot always be applied to weanling animals of the same species. Using the mATPase, despite the difficult handling, is an important tool to determine the different characteristics of the specific fibers in the skeletal muscle tissue.

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Background: Human Papillomavirus, HPV, is the main etiological factor for cervical cancer. Different studies show that in women infected with HPV there is a positive correlation between lesion grade and number of infiltrating macrophages, as well as with IL-10 higher expression. Using a HPV16 associated tumor model in mice, TC-1, our laboratory has demonstrated that tumor infiltrating macrophages are M2-like, induce T cell regulatory phenotype and play an important role in tumor growth. M2 macrophages secrete several cytokines, among them IL-10, which has been shown to play a role in T cell suppression by tumor macrophages in other tumor models. In this work, we sought to establish if IL-10 is part of the mechanism by which HPV tumor associated macrophages induce T cell regulatory phenotype, inhibiting anti-tumor activity and facilitating tumor growth. Results: TC-1 tumor cells do not express or respond to IL-10, but recruit leukocytes which, within the tumor environment, produce this cytokine. Using IL-10 deficient mice or blocking IL-10 signaling with neutralizing antibodies, we observed a significant reduction in tumor growth, an increase in tumor infiltration by HPV16 E7 specific CD8 lymphocytes, including a population positive for Granzyme B and Perforin expression, and a decrease in the percentage of HPV specific regulatory T cells in the lymph nodes. Conclusions: Our data shows that in the HPV16 TC-1 tumor mouse model, IL-10 produced by tumor macrophages induce regulatory phenotype on T cells, an immune escape mechanism that facilitates tumor growth. Our results point to a possible mechanism behind the epidemiologic data that correlates higher IL-10 expression with risk of cervical cancer development in HPV infected women.

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Background Data: Photodynamic therapy (PDT) involves the photoinduction of cytotoxicity using a photosensitizer agent, a light source of the proper wavelength, and the presence of molecular oxygen. A model for tissue response to PDT based on the photodynamic threshold dose (Dth) has been widely used. In this model cells exposed to doses below Dth survive while at doses above the Dth necrosis takes place. Objective: This study evaluated the light Dth values by using two different methods of determination. One model concerns the depth of necrosis and the other the width of superficial necrosis. Materials and Methods: Using normal rat liver we investigated the depth and width of necrosis induced by PDT when a laser with a gaussian intensity profile is used. Different light doses, photosensitizers (Photogem, Photofrin, Photosan, Foscan, Photodithazine, and Radachlorin), and concentrations were employed. Each experiment was performed on five animals and the average and standard deviations were calculated. Results: A simple depth and width of necrosis model analysis allows us to determine the threshold dose by measuring both depth and surface data. Comparison shows that both measurements provide the same value within the degree of experimental error. Conclusion: This work demonstrates that by knowing the extent of the superficial necrotic area of a target tissue irradiated by a gaussian light beam, it is possible to estimate the threshold dose. This technique may find application where the determination of Dth must be done without cutting the tissue.