991 resultados para Actor. Receiver. Reception. Presence. Representation


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The objective of the present survey was to assess the Brazilian scientific production in psychiatry, psychobiology, and mental health during the 1998-2002 period. The universities' graduate programs concentrate the vast majority of the scientific production in Brazil. We assessed the annual reports from the graduate programs to the Brazilian Ministry of Education concerning master's and doctoral theses and the articles published in journals indexed by the Institute of Scientific Information (ISI). There are nine Master's and Doctoral graduate programs dedicated to research in psychiatry, neuropsychiatry, psychobiology, and mental health in the country, seven being located in southern states. During the 5-year period, from 1998 to 2002, 186 students received their doctorate degree (37/year). The programs published 637 articles in journals indexed by ISI, the majority of them in journals with an impact factor higher than 2. The research advisors' productivity varied among graduate programs, ranging from 0.6 to 2.0 articles per year in ISI-indexed journals. Despite the substantial barriers faced by the Brazilian scientific community (mainly financial and writing difficulties), Brazil's scientific mental health production is on the rise. The number of articles published in ISI-indexed journals has doubled without a significant increase in the number of graduate theses, suggesting that there was an improvement in both the quality of the scientific production and the productivity of the graduate programs. Based on these data, it is reasonable to predict a tendency to an increase in production over the next few years.

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The goal of this thesis is to estimate the effect of the form of knowledge representation on the efficiency of knowledge sharing. The objectives include the design of an experimental framework which would allow to establish this effect, data collection, and statistical analysis of the collected data. The study follows the experimental quantitative design. The experimental questionnaire features three sample forms of knowledge: text, mind maps, concept maps. In the interview, these forms are presented to an interviewee, afterwards the knowledge sharing time and knowledge sharing quality are measured. According to the statistical analysis of 76 interviews, text performs worse in both knowledge sharing time and quality compared to visualized forms of knowledge representation. However, mind maps and concept maps do not differ in knowledge sharing time and quality, since this difference is not statistically significant. Since visualized structured forms of knowledge perform better than unstructured text in knowledge sharing, it is advised for companies to foster the usage of these forms in knowledge sharing processes inside the company. Aside of performance in knowledge sharing, the visualized structured forms are preferable due the possibility of their usage in the system of ontological knowledge management within an enterprise.

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The purpose of the present study was to identify the expression of p16INK4 in cervical cancer precursor lesions by immunohistochemistry and to correlate it with lesion grade and presence of human papillomavirus (HPV) infection. Cervical specimens from 144 women seen consecutively at the gynecology outpatient clinic of our institution from December 2003 to May 2005 were analyzed by cytopathology, histopathology, polymerase chain reaction for HPV-DNA, and p16INK4 immunostaining. Histologically normal biopsies, HPV-DNA negative by polymerase chain reaction, were used as control. HPV-DNA prevalence, including the control group, was 68.1% and the prevalence of p16INK4 expression was 55.0%. The percentage of cells stained by p16INK4 ranged from 10 to 100%, both in the group consisting of cervical intraepithelial neoplasia (CIN)1/HPV specimens and in the group of CIN2/CIN3 specimens with P value of 0.0001. p16INK4 expression was 48.3% in the CIN1/HPV group, as opposed to 94.3% in the CIN2/CIN3 group (P = 0.001), showing a statistically significant difference between the two groups. The quantitative method used here is simple and less subjective than the different semiquantitative methods described in the literature. In view of the different definitions of a p16INK4-positive case, it is almost impossible to compare the findings reported by different investigators. This study confirms the association between p16INK4 and CIN2 and CIN3 lesions. Moreover, it shows that some low grade lesions expressed high levels of this protein. This may indicate that such low grade lesions may be predisposed to progress to high grade lesions. This means that p16INK4 may be a strong marker for "neoplastic lesions" induced by HPV and not just an infection marker.

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Pretreatment of Escherichia coli cultures with the iron chelator 2,2’-dipyridyl (1 mM) protects against the lethal effects of low concentrations of hydrogen peroxide (<15 mM). However, at H2O2 concentrations equal to or greater than 15 mM, dipyridyl pretreatment increases lethality and mutagenesis, which is attributed to the formation of different types of DNA lesions. We show here that pretreatment with dipyridyl (1 mM) prior to challenge with high H2O2 concentrations (≥15 mM) induced mainly G:C→A:T transitions (more than 100X with 15 mM and more than 250X with 20 mM over the spontaneous mutagenesis rate) in E. coli. In contrast, high H2O2 concentrations in the absence of dipyridyl preferentially induced A:T→T:A transversions (more than 1800X and more than 300X over spontaneous mutagenesis for 15 and 20 mM, respectively). We also show that in the fpg nth double mutant, the rpoB gene mutation (RifS-RifR) induced by 20 mM H2O2 alone (20X higher) was increased in 20 mM H2O2 and dipyridyl-treated cultures (110X higher), suggesting additional and/or different lesions in cells treated with H2O2 under iron deprivation. It is suggested that, upon iron deprivation, cytosine may be the main damaged base and the origin of the pre-mutagenic lesions induced by H2O2.

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Toxoplasma, which infects all eukaryotic cells, is considered to be a good system for the study of drug action and of the behavior of infected host cells. In the present study, we asked if thiosemicarbazone derivatives can be effective against tachyzoites and which morphological and ultrastructural features of host cells and parasites are associated with the destruction of Toxoplasma. The compounds were tested in infected Vero cell culture using concentration screens (0.1 to 20 mM). The final concentration of 1 mM was chosen for biological assay. The following results were obtained: 1) These new derivatives decreased T. gondii infection with an in vitro parasite IC50% of 0.2-0.7 mM, without a significant effect on host cells and the more efficient compounds were 2, 3 (thiosemicarbazone derivatives) and 4 (thiazolidinone derivative); 2) The main feature observed during parasite elimination was continuous morphological disorganization of the tachyzoite secretory system, progressive organelle vesiculation, and then complete disruption; 3) Ultrastructural assays also revealed that progressive vesiculation in the cytoplasm of treated parasites did not occur in the host cell; 4) Vesiculation inside the parasite resulted in death, but this feature occurred asynchronously in different intracellular tachyzoites; 5) The death and elimination of T. gondii was associated with features such as apoptosis-like stage, acidification and digestion of parasites into parasitophorous vacuoles. Our results suggest that these new chemical compounds are promising for the elimination of intracellular parasites by mainly affecting tachyzoite development at 1 mM concentration for 24 h of treatment.

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Radiotherapy is one of the main approaches to cure prostate cancer, and its success depends on the accuracy of dose planning. A complicating factor is the presence of a metallic prosthesis in the femur and pelvis, which is becoming more common in elderly populations. The goal of this work was to perform dose measurements to check the accuracy of radiotherapy treatment planning under these complicated conditions. To accomplish this, a scale phantom of an adult pelvic region was used with alanine dosimeters inserted in the prostate region. This phantom was irradiated according to the planned treatment under the following three conditions: with two metallic prostheses in the region of the femur head, with only one prosthesis, and without any prostheses. The combined relative standard uncertainty of dose measurement by electron spin resonance (ESR)/alanine was 5.05%, whereas the combined relative standard uncertainty of the applied dose was 3.35%, resulting in a combined relative standard uncertainty of the whole process of 6.06%. The ESR dosimetry indicated that there was no difference (P>0.05, ANOVA) in dosage between the planned dose and treatments. The results are in the range of the planned dose, within the combined relative uncertainty, demonstrating that the treatment-planning system compensates for the effects caused by the presence of femur and hip metal prostheses.

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Listeria monocytogenes is a foodborne pathogen which may survive in biofilms and persist in food processing plants. In this study, the ability of Leuconostoc mesenteroides (bac+ and bac-) to inhibit biofilm formation by L. monocytogenes ATCC 19115 was studied with stainless steel coupons immersed in BHI broth and BHI broth plus sucrose in combination with the Lactic Acid Bacteria (LAB). Adhered cells were collected with swabs and enumerated on selective agars (Oxford for listeria and MRS for leuconostoc). Leuconostoc mesenteroides bac+ in co-culture with L. monocytogenes was effective to inhibit biofilm formation by listeria for up to 3 hours of incubation, but at 24 hours, biofilm was present in all conditions tested, as confirmed by observations of stainless steel coupons under Scanning Electron Microscopy (SEM). It was also observed that in the presence of L. mesenteroides bac+ in BHI plus sucrose, a high number of elongated cells of L. monocytogenes was present, which may indicate an adaptation response of the pathogen to stress conditions with important implications for food safety.

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Iron availability in the diet is very important because iron deficiency affects a large population in the world. The matrix where iron is present has an influence in its availability. The presence of β-carotene is a factor that alters the availability of iron. This research aims to estimate the iron availability in the presence of β-carotene in food mixtures: M1 = egg and pumpkin; M2 = spinach and pumpkin; M3 = spinach and cabbage; M4 = egg and cabbage; M5 = spinach and carrot; M6 = egg and carrot; M7 = bean and carrot; M8 = bean and pumpkin and M9 = bean and cabbage. After cooking, the following figures were determined: proximate composition, oxalic acid, phytic acid, tannin, iron, iron availability in vitro and β-carotene. The data were analyzed by Tukey test (5%). There were no significant statistical differences for oxalic acid. Tannin presented greater results in mixtures with spinach (M2 and M5); phytic acid was greater in bean samples (M7, M8 and M9) and with spinach (M2). Mixtures M5 e M7, with carrot, presented more β-carotene than the others. The best result for iron availability appeared in mixture (M6). A positive correlation was verified between protein and iron dialysis, and between lipids and iron dialysis. Dietetic fiber was an inhibitor to iron availability. Mixtures with egg showed greater iron availability

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The objective of this work was to verify the availability of iron in the presence of vitamin A as components of foods and in combinations with medicines. The iron available was measured in the presence of vitamin A in foods - common bean (B), beef liver (Li) and carrot (C) - and medicines - Fer-In-Sol® (Fer) (Mead Johnson), Arovit® (A) (Roche) and Neutrofer® (N) (Sigma Pharma) - as well as in combinations of both. β-carotene, vitamin A, total iron, heme and non heme iron, percentage of dialyzable iron and amount of dialyzable iron was determined. Vitamin A and β-carotene had a positive effect on the percentage of iron dialysis. Carrot and liver had a better percentage of dialyzable iron than their respective medicine at similar concentrations. Therefore, we can conclude that there has been an influence of vitamin A over the dialysis of iron, being the mixtures containing liver the ones which achieved the highest concentrations of dialyzable iron, and also that, according to the amounts needed to obtain the daily recommended intake of iron, they are good for consumption.

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Pisciculture is an economic activity that is steadily growing in the state of Parana, Brazil, and Nile tilapia (Oreochromis niloticus) is one of the widely cultivated species in this state. Tilapia is not only a very nutritious food, but also an important indicator of environmental contamination. This study aimed to verify contamination by cadmium, copper and lead in tilapia fillets, and to compare the found values to international legislations. Were collected 135 samples of tilapia fillets, between July 2006 and May 2007, in three fish stores located in regions west and north of Paraná State. Samples of tilapia fillet were analyzed in relation to the presence of cadmiun, lead and copper, using atomic absorption spectrophotometry. Lead has not been detected in the analyses. Cadmium has been detected in three samples, on concentrations of 0.012 µg.g-1, 0.011 µg.g-1 and 0.014 µg.g-1. Copper has been detected in all fillets, and the average concentration of each cold storage plant was of 0.122 µg.g-1, 0.106 µg.g-1 and 0.153 µg.g-1. The concentrations found in this study are within the limits allowed by both the European and the Australian legislations.

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The increased marketing of olive oil in Brazil has intensified legal requirements to ensure regulation of this product. The measurement of the specific extinction at 270 nm (E 270) and content of stigmastadiene can be used to assess the presence of refined oils in virgin olive oil. During the vegetable oil refining process, compounds with conjugated double bonds are generated from unsaturated fatty acids that absorb at 270 nm and sterols, such as stigmasta-3,5-diene. To compare these parameters, seven samples of extra virgin olive oil and three samples of olive oil (blend of virgin and refined) were analyzed. Among the samples analyzed, four extra virgin samples had levels of stigmastadiene and E 270 higher than expected, among which two were adulterated with seed oil (rich in linoleic acid) and the other two with olive pomace oil. The results demonstrate the higher sensitivity of stigmastadiene to determine the presence of the refined oil in virgin olive oil and good agreement with determining E 270. The latter technique is a simple, quick, and low cost method of determination that can be easily implemented in laboratories to assist in the screening and regulation of olive oils sold in Brazil.

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Milkborne transmission of Shiga toxin- producing Escherichia coli (STEC) has raised considerable concern due to recent outbreaks worldwide and poses a threat to public health. The aim of this study was to develop a sensitive and specific multiplex PCR assay to detect the presence of STEC in bovine raw milk. To identify E. coli (ATCC 25922) contamination, the gene uspA was used, and PCR sensitivity and specificity were accessed by testing diluted samples ranging from 2 to 2.0 × 10(6) CFU/mL. To detect STEC, the stx1 and stx2 genes were selected as targets. After reaction standardization, the multiplex assay was tested in raw milk collected from 101 cows on dairy farms. PCR assay for E. coli detection had a specificity of 100% and sensitivity of 79% (P<0.0001), with a lower detection limit of 2 CFU/mL. Multiplex PCR assay had 100% sensitivity for E. coli positive raw milk samples, and 31.1% were contaminated with STEC, 28.3% of stx2, and 1.9% of stx1. The multiplex PCR assay described in the present study can be employed to identify and screen E. coli harboring stx1 and stx2 genes in raw milk on dairy farms and in industries.

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Abstract Bovine Spongiform Encephalopathy (BSE) is a virulent disease which may infect by affecting the central nervous system (CNS) tissues in cattle and causes degeneration in nerves. Central nervous system tissues such as brain and spinal cord which are classified as specified risk materials (SRMs) are regarded to be main source of infection. The contamination of the meat with the specific risk materials (SRMs) can occur in phases of slaughter, fragmentation of carcass and processing. This study was conducted in order to investigate the existence of CNS tissues in raw meat ball (cig kofte) which is commonly consumed in the Southeastern Region of Turkey, particularly in Şanlıurfa. For this purpose, 145 samples of raw meat ball were tested. The enzyme-linked immunosorbent assay (ELISA) kits (Ridascreen risk material 10/5, R-biofarm GmbH) which determine glial fibrillary acidic protein (GFAP) as determinant were used. As a result of the analyses, positivity was detected in 21 of totally 145 samples of raw meat ball (14.48%). 6 (4.14%) of the samples gave low level of positivity (≥ 0.1 standard absorbance), 10 (6.90%) gave medium level of positivity (>0.2 standard absorbance) and 5 (3.45%) gave high level of positivity (≥0.5 standard absorbance). As a consequence, meats are contaminated in any phase of both slaughter and meat production even if accidentally. Regarding this matter, necessary measures should be taken and hygiene rules should be applied.