949 resultados para Cardigos, Isabel: In and out of enchantment


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Molecular dynamics simulations are used to study the interaction of low-energy Ar atoms with the Ni(001) surface, Angular scattering distributions, in and out of the plane of incidence, are investigated as a function of incident energy, angles of incidence, crystallographic orientation of the incident beam and surface temperature. The results show a clear transition to the structure scattering regime at around 2 eV. However, at lower energies, two sub-regimes are revealed by the simulations, Far energies up to 250 meV, scattering is mainly diffuse, and significant trapping on the surface is observed, At energies above this level, lobular patterns start to form and trapping decreases with the increase in energy, Generally, there is a weak temperature dependence, but variations in the angle of incidence and/or changes in the crystallographic direction, generate significant changes in the scattering patterns.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Copyright: © 2014 Rodrigues et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Recent data suggest that the clinical course of reactional states in leprosy is closely related to the cytokine profile released locally or systemically by the patients. In the present study, patients with erythema nodosum leprosum (ENL) were grouped according to the intensity of their clinical symptoms. Clinical and immunological aspects of ENL and the impact of these parameters on bacterial load were assessed in conjunction with patients' in vitro immune response to mycobacterial antigens. In 10 out of the 17 patients tested, BI (bacterial index) was reduced by at least 1 log from leprosy diagnosis to the onset of their first reactional episode (ENL), as compared to an expected 0.3 log reduction in the unreactional group for the same MDT (multidrug therapy) period. However, no difference in the rate of BI reduction was noted at the end of MDT among ENL and unreactional lepromatous patients. Accordingly, although TNF-alpha (tumor necrosis factor) levels were enhanced in the sera of 70.6% of the ENL patients tested, no relationship was noted between circulating TNF-alpha levels and the decrease in BI detected at the onset of the reactional episode. Evaluation of bacterial viability of M. leprae isolated from the reactional lesions showed no growth in the mouse footpads. Only 20% of the patients demonstrated specific immune response to M. leprae during ENL. Moreover, high levels of soluble IL-2R (interleukin-2 receptor) were present in 78% of the patients. Circulating anti-neural (anti-ceramide and anti-galactocerebroside antibodies) and anti-mycobacterial antibodies were detected in ENL patients' sera as well, which were not related to the clinical course of disease. Our data suggest that bacterial killing is enhanced during reactions. Emergence of specific immune response to M. leprae and the effective role of TNF-alpha in mediating fragmentation of bacteria still need to be clarified.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A seroepidemiological survey was carried out during 1994 in the municipality of Paracambi, state of Rio de Janeiro. Haemagglutination inhibition test positivity was detected in 145 out of 370 (39.2%) schoolchildren. The frequency of positive test by sex was 53.8% (78/145) female and 46.2% (67/145) male. Distribution by age showed the increasing of antibody posivity in older children. Strains of dengue virus type 1 and dengue virus type 2 were isolated before (1990) showing the co-circulation of both serotypes in that area. The house index infestation of Aedes albopictus and Aedes aegypti has been determined.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The association between pyogenic liver abscesses and schistosomiasis has been confirmed by clinical and experimental studies. In this retrospective study of 78 patients with pyogenic liver abscesses the association with schistosomiasis has been investigated. Pyodermitis, a known focus of bacteremia, was observed in 19 patients (24%). Blood eosinophilia was observed in 30 patients (39%). Staphylococcus aureus was cultured from abscesses in 17 out of 38 patients (45%). Forty-one out of 57 patients (53%) had stool examination. Schistosoma mansoni was the main parasite identified. Eggs of S. mansoni were also identified in liver biopsies in 7 out of 19 patients who did the exam. The large number of young patients with liver abscesses described here is different from what has been observed in developed countries. This clinical study provide support for the concept that granulomas of S. mansoni in the liver are foci for colonization with S. aureus, which in presence of staphylococcal bacteremia can form liver abscesses.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In order to study the infectious agents causing human disseminated cryptococcosis in the state of Pará, North Brazil, 56 isolates of Cryptococcusspp. (54 isolated from cerebral spinal fluid and two from blood cultures) from 43 cases diagnosed between 2003-2007 were analysed. The species were determined through morphological and physiological tests and genotypes were determined by URA5-RFLP and PCR-fingerprinting (wild-type phage M13). The following species and genotypes were identified: Cryptococcus neoformans VNI (28/56, 50%), Cryptococcus gattii VGII (25/56, 44.64%) and C. gattii VGI (3/56, 5.26%). The genotype VNI occurred in 12 out of 14 HIV-positive adults, whereas the genotype VGII occurred in 11 out of 21 HIV-negative adults (p < 0.02, OR = 6.6 IC95% 0.98-56.0). All patients less than 12 years old were HIV negative and six cases were caused by the VGII genotype, one by the VGI and one by VNI. Therefore, endemic primary mycosis in HIV-negative individuals, including an unexpectedly high number of children, caused by the VGII genotype deserves further study and suggests the need for surveillance on cryptococcal infection in the state of Pará, Eastern Amazon.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Rhodnius ecuadoriensis is considered the second most important vector of Chagas disease in Ecuador. It is distributed across six of the 24 provinces and occupies intradomiciliary, peridomiciliary and sylvatic habitats. This study was conducted in six communities within the coastal province of Guayas. Triatomine searches were conducted in domestic and peridomestic habitats and bird nests using manual searches, live-bait traps and sensor boxes. Synantrhopic mammals were captured in the domestic and peridomestic habitats. Household searches (n = 429) and randomly placed sensor boxes (n = 360) produced no live triatomine adults or nymphs. In contrast, eight nymphs were found in two out of six searched Campylorhynchus fasciatus (Troglodytidae) nests. Finally, Trypanosoma cruzi DNA was amplified from the blood of 10% of the 115 examined mammals. Environmental changes in land use (intensive rice farming), mosquito control interventions and lack of intradomestic adaptation are suggested among the possible reasons for the lack of domestic triatomine colonies.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Genetic caste determination has been described in two populations of Pogonomyrmex harvester ants, each comprising a pair of interbreeding lineages. Queens mate with males of their own and of the alternate lineage and produce two types of diploid offspring, those fertilized by males of the queens' lineage which develop into queens and those fertilized by males of the other lineage which develop into workers. Each of the lineages has been shown to be itself of hybrid origin between the species Pogonomyrmex barbatus and Pogonomyrmex rugosus, which both have typical, environmentally determined caste differentiation. In a large scale genetic survey across 35 sites in Arizona, New Mexico and Texas, we found that genetic caste determination associated with pairs of interbreeding lineages occurred frequently (in 26 out of the 35 sites). Overall, we identified eight lineages with genetic caste determination that always co-occurred in the same complementary lineage pairs. Three of the four lineage pairs appear to have a common origin while their relationship with the fourth remains unclear. The level of genetic differentiation among these eight lineages was significantly higher than the differentiation between P. rugosus and P. barbatus, which questions the appropriate taxonomic status of these genetic lineages. In addition to being genetically isolated from one another, all lineages with genetic caste determination were genetically distinct from P. rugosus and P. barbatus, even when colonies of interbreeding lineages co-occurred with colonies of either putative parent at the same site. Such nearly complete reproductive isolation between the lineages and the species with environmental caste determination might prevent the genetic caste determination system to be swept away by gene flow.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Capacity is affected by construction type and its intensity on adjacent open traffic lanes. The effect on capacity is a function of vehicles moving in and out of the closed lanes of the work zone, and the presence of heavy construction vehicles. Construction activity and its intensity, however, are not commonly considered in estimating capacity of a highway lane. The main purpose of this project was to attempt to quantify the effects of construction type and intensity (e.g. maintenance, rehabilitation, reconstruction, and milling) on work zone capacity. The objective of this project is to quantify the effects of construction type and its intensity on work zone capacity and to develop guidelines for MoDOT to estimate the specific operation type and intensity that will improve the traffic flow by reducing the traffic flow and queue length commonly associated with work zones. Despite the effort put into field data collection, the data collected did not show a full speed-flow chart therefore extracting a reliable capacity value was difficult. A statistical comparison between the capacity values found in this study using either methodologies indicates that there is an effect of construction activity on the values work zone capacity. It was found that the heavy construction activity reduces the capacity. It is very beneficial to conduct similar studies on the capacity of work zone with different lane closure barriers, which is also directly related to the type of work zone being short-term or long-term work zones. Also, the effect of different geometric and environmental characteristics of the roadway should be considered in future studies.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Background: The pathogenic role of anti-HLA antibodies (AHA) after kidney transplantation is well established. However, its significance after liver transplantation remains unclear. The aim of our study was to determine the prevalence and significance of AHA after liver transplantation. Methods: Between January 2007 and November 2007, all liver transplant recipients who were greater than 6 months posttransplantation and followed regularly at our transplant outpatient clinic (n = 95) were screened for AHA. All clinical and electronic records were reviewed. Serum samples were tested using multiplex technology (Luminex). A liver biopsy had been performed in 55 out of the 95 patients based on clinical grounds but no routine protocol biopsies were performed. Immunosuppression was calcineurin inhibitor-based in 90 patients, sirolimus-based in 4 patients and one patient had no anti-rejection therapy (operationally tolerant recipient). Results: The mean time from transplantation to study was 85 months (range 6-248 months). Overall, AHA were found in 23/95 (24.2%) of patients (5 had anti-class I alone, 13 anti-class II alone, and 4 had both anti-class I and II). However, only 4/95 patients (4.2%) had donor-specific antibodies (DSA) (one anti-class I and 3 anti-class II). Twenty-one out of 95 patients (22.1%) had a history of past or current biopsy-proven or radiological biliary complications (chronic rejection, ischemic cholangitis, ischemic type biliary lesions or biliary anastomosis stricture). Among patients with AHA, 4/23 (17,4%) had biliary complications, while it was 17/72 (23.6%) in patients without AHA (NS). Among patients with DSA, 3/4 (75%) had biliary complications (two with biopsy-proven chronic rejection in association with biliary strictures and one with ischemic cholangitis following hepatic artery thrombosis), versus 1/19 (5.3%) patients with AHA but no DSA (p = 0.009), versus 16/72 (22.2%) patients without AHA (p = 0.046). In patients with DSA, immunosuppression was not different than in patients without DSA. Conclusions: We found a 24% AHA prevalence. The presence of DSA, but not of AHA, was significantly associated with an increased incidence of biliary complications including chronic liver allograft rejection. The exact mechanisms and possible causal relationship linking DSA to biliary complications remain to be studied. Larger prospective trials are thus needed to further define the role of AHA and in particular of DSA after liver transplantation.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This work consists of three essays investigating the ability of structural macroeconomic models to price zero coupon U.S. government bonds. 1. A small scale 3 factor DSGE model implying constant term premium is able to provide reasonable a fit for the term structure only at the expense of the persistence parameters of the structural shocks. The test of the structural model against one that has constant but unrestricted prices of risk parameters shows that the exogenous prices of risk-model is only weakly preferred. We provide an MLE based variance-covariance matrix of the Metropolis Proposal Density that improves convergence speeds in MCMC chains. 2. Affine in observable macro-variables, prices of risk specification is excessively flexible and provides term-structure fit without significantly altering the structural parameters. The exogenous component of the SDF is separating the macro part of the model from the term structure and the good term structure fit has as a driving force an extremely volatile SDF and an implied average short rate that is inexplicable. We conclude that the no arbitrage restrictions do not suffice to temper the SDF, thus there is need for more restrictions. We introduce a penalty-function methodology that proves useful in showing that affine prices of risk specifications are able to reconcile stable macro-dynamics with good term structure fit and a plausible SDF. 3. The level factor is reproduced most importantly by the preference shock to which it is strongly and positively related but technology and monetary shocks, with negative loadings, are also contributing to its replication. The slope factor is only related to the monetary policy shocks and it is poorly explained. We find that there are gains in in- and out-of-sample forecast of consumption and inflation if term structure information is used in a time varying hybrid prices of risk setting. In-sample yield forecast are better in models with non-stationary shocks for the period 1982-1988. After this period, time varying market price of risk models provide better in-sample forecasts. For the period 2005-2008, out of sample forecast of consumption and inflation are better if term structure information is incorporated in the DSGE model but yields are better forecasted by a pure macro DSGE model.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This study aims to synthesize and characterize organoclays developed from an Argentinian montmorillonite (Bent) using hexadecyltrimethylammonium bromide (HDTMA-Br) as the intercalation agent. Subsequently, an adsorption mechanism is proposed. The obtained organoclays were more hydrophobic than the starting clay. Surfactant molecules were adsorbed initially through cation exchange in sites placed in the interlayer space of the clay. Adsorption in such sites continued until the interlayer space was saturated. Depending on the surfactant loading introduced during the intercalation process, different organizations of surfactant in the interlayer were obtained. Further adsorption of surfactant occurred in the mesopores generated by tactoids in the "house of cards" organization. This process kept surfactant molecules relatively free and out of the interlayer space.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The focus of the research is on the derivation of the valid and reliable performance results regarding establishment and launching of the new full-scale industrial facility, considering the overall current conditions for the project realization in and out of Russia. The study demonstrates the process of the new facility concept development, with following perfor-mance calculation, comparative analyzes conduction, life-cycle simulations, performance indicators derivation and project`s sustainability evaluation. To unite and process the entire input parameters complexity, regards the interlacing between the project`s internal technical and commercial sides on the one hand, and consider all the specifics of the Russian conditions for doing business on the other hand, was developed the unique model for the project`s performance calculation, simulations and results representation. The complete research incorporates all corresponding data to substantiate the assigned facility`s design, sizing and output capacity for high quality and cost efficient ferrous pipe-line accessories manufacturing, as well as, demonstrates that this project could be suc-cessfully realized in current conditions in Russia and highlights the room for significant performance and sustainability improvements based on the indexes of the derived KPIs.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The phenomenon of communitas has been described as a moment 'in and out of time' in which a collective of individuals may be experienced by one as equal and individuated in an environment stripped of structural attributes (Turner, 1 969). In these moments, emotional bonds form and an experience of perceived 'oneness' and synergy may be described. As a result of the perceived value of these experiences, it has been suggested by Sharpe (2005) that more clearly understanding how this phenomenon may be purposefully facilitated would be beneficial for leisure service providers. Consequently, the purpose of this research endeavor was to examine the ways in which a particular leisure service provider systematically employs specific methods and sets specific parameters with the intention of guiding participants toward experiences associated with communitas or "shared spirit" as described by the organization. A qualitative case study taking a phenomenological approach was employed in order to capture the depth and complexity of both the phenomenon and the purposefiil negotiation of experiences in guiding participants toward this phenomenon. The means through which these experiences were intentionally facilitated was recreational music making in a group drumming context. As such, an organization which employs specific methods of rhythm circle facilitation as well as trains other facilitators all over the world was chosen purposely for their recognition as the most respectable and credible in this field. The specific facilitator was chosen based on high recommendation by the organization due to her level of experience and expertise. Two rhythm circles were held, and participants were chosen randomly by the facilitator. Data was collected through observation in the first circle and participant- observation in the second, as well as through focus groups with circle participants. Interviews with the facilitator were held both initially to gain broad understanding of concepts and phenomenon as well as after each circle to reflect on each circle specifically. Data was read repeatedly to drawn out patterns which emerged and were coded and organized accordingly. It was found that this specific process or system of implementation lead to experiences associated with communitas by participants. In order to more clearly understand this process and the ways in which experiences associated with communitas manifest as a result of deliberate facilitator actions, these objective facilitator actions were plotted along a continuum relating to subjective participant experiences. These findings were then linked to the literature with regards to specific characteristics of communitas. In so doing, the intentional manifestation of these experiences may be more clearly understood for ftiture facilitators in many contexts. Beyond this, findings summarized important considerations with regards to specific technical and communication competencies which were found to be essential to fostering these experiences for participants within each group. Findings surrounding the maintenance of a fluid negotiation of certain transition points within a group rhythm event overall were also highlighted, and this fluidity was found to be essential to the experience of absorption and engagement in the activity and experience. Emergent themes of structure, control, and consciousness have been presented as they manifested and were found to affect experiences within this study. Discussions surrounding the ethics and authenticity of these particular methods and their implementation has also been generated throughout. In conclusion, there was a breadth as well as depth of knowledge found in unpacking this complex process of guiding individuals toward experiences associated with communitas. The implications of these findings contribute in broadening the current theoretical as well as practical understanding as to how certain intentional parameters may be set and methods employed which may lead to experiences of communitas, and as well contribute a greater knowledge to conceptualizing the manifestation of these experiences when broken down.