23 resultados para Preservation rules
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)
Resumo:
A redução da disponibilidade de espécies de madeiras nativas e seus efeitos na economia, associada ao fortalecimento dos conceitos de preservação ambiental, criou a necessidade de desenvolvimento de alternativas viáveis para utilização racional de espécies de reflorestamento. E uma das opções é a realização de classificação visual das peças. Autores de trabalhos desenvolvidos nessa linha de pesquisa verificaram a adequação das regras de classificação visual do Southern Pine Inspection Bureau (SPIB) dos EUA à madeira de Pinus do Brasil e apresentaram proposta para normalizar o processo de classificação visual dessa madeira. Nessa classificação, os aspectos com maior influência são: presença de nós, desvio de grã em relação ao eixo da peça e densidade de anéis de crescimento. Assim, esta pesquisa apresenta um estudo experimental que consistiu na classificação visual e determinação da resistência à tração de 85 peças de Pinus spp e um estudo teórico, que propôs uma equação para determinar a resistência à tração média de peças estruturais em função da classificação visual. Com este trabalho, foi possível observar a influência dos nós e dos anéis de crescimento sobre a resistência à tração das peças analisadas.
Resumo:
Kinosternon scorpioides é uma pequena tartaruga semi-aquática, típica de água doce, de distribuição geográfica bastante diversificada, encontrada no estado do Maranhão, onde é denominada de jurará ou muçuã. Sua carne é uma excelente fonte de proteína e a despeito da legislação vigente, é comercializado nas praias e feiras da cidade de São Luís e consumido nos restaurantes sob a forma de farofa servida em casquinha. Os órgãos genitais do macho foram estudados visando fornecer dados morfológicos da própria espécie, que poderão ser utilizados na biologia reprodutiva voltada para ações de preservação em cativeiro. Compõe-se a amostra de 10 machos adultos, obtidos mediante apreensões do IBAMA-MA (Proc. nº 020.12.002400/99-31, licença nº 002/01), os quais foram eutanaziados conforme normas do Comitê de Ética do Curso de Medicina Veterinária, Universidade Estadual do Maranhão. A cavidade celomática foi aberta e os órgãos fixados em solução aquosa de formaldeído 10%, e posteriormente dissecados. Os testículos possuem formato ovóide e coloração amarelo-ouro. Os epidídimos convolutos estavam aderidos dorsalmente à superfície medial dos testículos, terminando em um pequeno ducto deferente. Os ductos deferentes não forma-ram nenhuma ampola distinta, abrindo-se na cloaca. O pênis sulcado, localizado no assoalho da cloaca, estendeu-se até a cauda, composto de raíz, corpo e glande. A morfologia dos órgãos reprodutivos destes animais assemelha-se aos de outras tartarugas, sugerindo uma morfologia conservada entre as tartarugas.
Resumo:
We use QCD sum rules (QCDSR) to calculate the width of the radiative decay of the meson X(3872), assumed to be a mixture between charmonium and exotic molecular [c (q) over bar][q (c) over bar] states with J(PC) = 1(++). We find that in a small range for the values of the mixing angle, 5 degrees <= theta <= 13 degrees, we get the branching ratio Gamma(X -> J/psi gamma)/Gamma(X -> J/psi pi(+)pi(-)) = 0.19 +/- 0.13, which is in agreement, with the experimental value. This result is compatible with the analysis of the mass and decay width of the mode J/psi(n pi) performed in the same approach.
Resumo:
We evaluate the mass of the B(s0) scalar meson and the coupling constant in the B(s0)BK vertex in the framework of QCD sum rules. We consider the B(s0) as a tetraquark state to evaluate its mass. We get m(Bs0) = (5.85 +/- 0.13) GeV, which is in agreement, considering the uncertainties, with predictions supposing it as a b (s) over bar state or a B (K) over bar bound state with J(P) = 0(+). To evaluate the g(Bs0BK) coupling, we use the three-point correlation functions of the vertex, considering B(s0) as a normal b (s) over bar state. The obtained coupling constant is: g(Bs0BK) = (16.3 +/- 3.2) GeV. This number is in agreement with light-cone QCD sum rules calculation. We have also compared the decay width of the B(s0) -> BK process considering the B(s0) to be a b (s) over bar state and a BK molecular state. The width obtained for the BK molecular state is twice as big as the width obtained for the b (s) over bar state. Therefore, we conclude that with the knowledge of the mass and the decay width of the B(s0) meson, one can discriminate between the different theoretical proposals for its structure.
Resumo:
We use QCD sum rules to test the nature of the meson X(3872), assumed to be a mixture between charmonium and exotic molecular [c (q) over bar][q (c) over bar] states with J(PC) = 1(++). We find that there is only a small range for the values of the mixing angle theta that can provide simultaneously good agreement with the experimental value of the mass and the decay width, and this range is 5(0) <= theta <= 3(0). In this range we get m(X) = (3.77 +/- 0.18) GeV and Gamma(X -> J/psi pi(+)pi(-)) = (9.3 +/- 6.9) MeV, which are compatible, within the errors, with the experimental values. We, therefore, conclude that the X(3872) is approximately 97% a charmonium state with 3% admixture of similar to 88% D(0)D*(0) molecule and similar to 12% D(+)D*(-) molecule.
Resumo:
We investigate the widths of the recently observed charmonium like resonances X(3872), Z(4430), and Z(2)(4250) using QCD sum rules. Extending previous analyses regarding these states as diquark-antiquark states or molecules of D mesons, we introduce the Breit-Wigner function in the pole term. We find that introducing the width increases the mass at the small Borel window region. Using the operator-product expansion up to dimension 8, we find that the sum rules based on interpolating current with molecular components give a stable Borel curve from which both the masses and widths of these resonances can be well obtained. Thus the QCD sum rule approach strongly favors the molecular description of these states.
Resumo:
Here, I investigate the use of Bayesian updating rules applied to modeling how social agents change their minds in the case of continuous opinion models. Given another agent statement about the continuous value of a variable, we will see that interesting dynamics emerge when an agent assigns a likelihood to that value that is a mixture of a Gaussian and a uniform distribution. This represents the idea that the other agent might have no idea about what is being talked about. The effect of updating only the first moments of the distribution will be studied, and we will see that this generates results similar to those of the bounded confidence models. On also updating the second moment, several different opinions always survive in the long run, as agents become more stubborn with time. However, depending on the probability of error and initial uncertainty, those opinions might be clustered around a central value.
Resumo:
To determine the effect of storage on fungal survival, mummified cadavers of the cassava green mite pathogen, Neozygites tanajoae were placed at different conditions of temperature and relative humidity. The best condition for long-term preservation was -10 degrees C. At this condition, the fungus retained viability for 10 years when the experiment was terminated, with a decrease in sporulation with time. Cadavers placed at 4 degrees C and 5% RH sporulated for 2 years, while the fungus survived for only 7 days at 25 degrees C and 50% RH.
Resumo:
This study compared different temperatures and dormancy-reversion procedures for preservation of Phakopsora pachyrhizi uredospores. The storage temperatures tested were room temperature, 5 degrees C, -20 degrees C and -80 degrees C. Dehydrated and non-dehydrated uredospores were used, and evaluations for germination (%) and infectivity (no. of lesions/cm(2)) were made with fresh harvested spores and after 15, 29 76, 154 and 231 days of storage. The dormancy-reversion procedures evaluated were thermal shock (40 degrees C/5 min) followed or not by hydration (moist chamber,24 h). Uredospores stored at room temperature were viable only up to a month of storage, regardless of their hydration condition. Survival of uredospores increased with storage at lower temperatures. Dehydration of uredospores prior to storage increased their viability, mainly for uredospores stored at 5 degrees C, -20 degrees C and -80 degrees C. At 5 degrees C and -20 degrees C, dehydrated uredospores showed increases in viability of at least 47 and 127 days, respectively, compared to non-dehydrated spores. Uredospore germination and infectivity after storage for 231 days (7.7 months), could only be observed at -80 degrees C, for both hydration conditions. At this storage temperature, dehydrated and non-dehydrated uredospores exhibited 56 and 28% of germination at the end of the experiment, respectively. Storage at -80 degrees C also maintained uredospore infectivity, based upon levels of Infection frequency, for both hydration conditions. Among the dormancy-reversion treatments applied to spores stored at -80 degrees C, those involving hydration allowed recoveries of 85 to 92% of the initial germination.
Resumo:
A stable matching rule is used as the outcome function for the Admission game where colleges behave straightforwardly and the students` strategies are given by their preferences over the colleges. We show that the college-optimal stable matching rule implements the set of stable matchings via the Nash equilibrium (NE) concept. For any other stable matching rule the strategic behavior of the students may lead to outcomes that are not stable under the true preferences. We then introduce uncertainty about the matching selected and prove that the natural solution concept is that of NE in the strong sense. A general result shows that the random stable matching rule, as well as any stable matching rule, implements the set of stable matchings via NE in the strong sense. Precise answers are given to the strategic questions raised.
Resumo:
The capacity to distinguish colony members from strangers is a key component in social life. In social insects, this extends to the brood and involves discrimination of queen eggs. Chemical substances communicate colony affiliation for both adults and brood; thus, in theory, all colony members should be able to recognize fellow nestmates. In this study, we investigate the ability of Dinoponera quadriceps workers to discriminate nestmate and non-nestmate eggs based on cuticular hydrocarbon composition. We analyzed whether cuticular hydrocarbons present on the eggs provide cues of discrimination. The results show that egg recognition in D. quadriceps is related to both age and the functional role of workers. Brood care workers were able to distinguish nestmate from non-nestmate eggs, while callow and forager workers were unable to do so.
Resumo:
Objective: To evaluate the impact of systematic use of intraoperative Doppler ultrasound during microsurgical subinguinal varicocele repair. Design: Prospective clinical study. Setting: Andrology laboratory and male infertility section of the urology department of a tertiary care hospital. Patient(s): Two hundred and thirteen men with clinical varicocele. Intervention(s): Subinguinal microsurgical varicocele ligation using an intraoperative vascular Doppler flow detector. Main Outcome Measure(s): Number of veins ligated, lymphatic spared, arteries identified or accidentally ligated. Result(s): A statistically significant greater number of arteries were identified and preserved when intraoperative vascular Doppler was used. In addition, the average number of internal spermatic veins ligated was statistically significantly greater in the same group. Accidental artery ligation occurred in two cases (1.1%) in which the Doppler was not applied. There was no statistically significant difference in number of lymphatics spared between groups. Conclusion(s): Our findings showed that concomitant use of intraoperative vascular Doppler during microsurgical varicocelectomy allows more arterial branches to be preserved, and more internal spermatic veins are likely to be ligated. This device should be considered an attractive tool to improve surgical outcomes and safety. (Fertil Steril (R) 2010; 93: 2396-9. (C)2010 by American Society for Reproductive Medicine.)
Resumo:
Introduction. Lung tranplantation, a consolidated treatment for end-stage lung disease, utilizes preservation solutions, such as low potassium dextran (LPD), to mitigate ischemia reperfusion injury. We sought the local development of LPD solutions in an attempt to facilitate access and enhance usage. We also sought to evaluate the effectiveness of a locally manufactured LPD solution in a rat model of ex vivo lung perfusion. Methods. We randomized the following groups \?\adult of male Wistar rats (n = 25 each): Perfadex (LPD; Vitro life, Sweden); locally manufactured LPD-glucose (LPDnac) (Farmoterapica, Brazil), and normal saline solution (SAL) with 3 ischemic times (6, 12, and 24 hours). The harvested heart lung blocks were flushed with solution at 4 C. After storage, the blocks were connected to an IL-2 Isolated Perfused Rat or Guinea Pig Lung System (Harvard Apparatus) and reperfused with homologous blood for 60 minutes. Respiratory mechanics, pulmonary artery pressure, perfusate blood gas analysis, and lung weight were measured at 10-minute intervals. Comparisons between groups and among ischemic times were performed using analysis of variance with a 5% level of significance. Results. Lungs preserved for 24 hours were nonviable and therefore excluded from the analysis. Those preserved for 6 hours showed better ventilatory mechanics when compared with 12 hours. The oxygenation capacity was not different between lungs flushed with LPD or LPDnac, regardless of the ischemic time. SAL lungs showed higher PCO(2) values than the other solutions. Lung weight increased over time during perfusion; however, there were no significant differences among the tested solutions (LPD, P = .23; LPDnac, P = .41; SAL, P = .26). We concluded that the LPDnac solution results in gas exchange were comparable to the original LPD (Perfadex); however ventilatory mechanics and edema formation were better with LPD, particularly among lungs undergoing 6 hours of cold ischemia.
Resumo:
We report our results of orthotopic ileal neobladder after radical cystectomy with prostatic adenomectomy with regard to urinary continence, sexual outcome and disease control. Between March 2003 and July 2004, 22 men with bladder transitional cell carcinoma (mean age 65.0) were analyzed. They underwent radical cystectomy with prostatic adenomectomy with preservation of the prostatic capsule, seminal vesicles and orthotopic ileal neobladder. Urinary continence was assessed after 2 days, 2 months, 6 months and 1 year. Preservation of sexual function was defined as the ability to have sexual intercourse and was assessed after 2-, 6-, and 12-months postoperatively. Overall survival and cancer-specific survival were assessed. Median postoperative follow-up was 60 months. Daytime and nighttime urinary continence after 48 h was 47 and 14%, respectively. After 2, 6 and 12 months, these rates were 74 and 16%, 85 and 26%, and 94 and 31%, respectively. Sexual intercourse was achieved in 69% of patients. Overall survival rate was 68%, and cancer-specific survival rate was 73%. Overall survival rates according to pathologic stage for pT0, pT1, pT2 and pT3 were 100, 60, 71 and 57%, and cancer-specific survival were 100, 80, 71 and 57%, respectively. Urinary continence and sexual function achieved by radical cystectomy with prostatic adenomectomy with orthotopic ileal neobladder seem to be similar to those achieved by the conventional technique with satisfactory oncologic results.
Resumo:
Gangliosides are known to be important in many biological processes. However, details concerning the exact function of these glycosphingolipids in cell physiology are poorly understood. in this study, the role of gangliosides present on the surface of rodent mast cells in maintaining cell structure was examined using RBL-2H3 mast cells and two mutant cell lines (E5 and D1) deficient in the gangliosides, GM(1) and the alpha-galactosyl derivatives of the ganglioside GD(1b). The two deficient cell lines were morphologically different from each other as well as from the parental RBL-2H3 cells. Actin filaments in RBL-2H3 and E5 cells were under the plasma membrane following the spindle shape of the cells, whereas in D1 cells, they were concentrated in large membrane ruffles. Microtubules in RBL-2H3 and E5 cells radiated from the centrosome and were organized into long, straight bundles. The bundles in D1 cells were thicker and organized circumferentially under the plasma membrane. The endoplasmic reticulum, the Golgi complex, and the secretory granule matrix were also altered in the mutant cell lines. These results suggest that the mast cell-specific alpha-galactosyl derivatives of ganglioside GD(1b) and GM(1) are important in maintaining normal cell morphology. (J Histochern Cytochem 58:83-93, 2010)