885 resultados para The Importance of Rubber
Resumo:
Host cell apoptosis plays an important immune regulatory role in parasitic infections. Infection of mice with Trypanosoma cruzi, the causative agent of Chagas disease, induces lymphocyte apoptosis. In addition, phagocytosis of apoptotic cells stimulates the growth of T. cruzi inside host macrophages. In spite of progress made in this area, the importance of apoptosis in the pathogenesis of Chagas disease remains unclear. Here we review the evidence of apoptosis in mice and humans infected with T. cruzi. We also discuss the mechanisms by which apoptosis can influence underlying host responses and tissue damage during Chagas disease progression.
Resumo:
The aim of this paper was to analyse the active dispersal of Triatoma infestans and the role of chickens as passive carriers of this insect in peridomestic areas of La Rioja, Argentina. To measure active dispersal, monthly catches were made on six consecutive nights for five months (in the warm season) using light traps (for flying insects) and sticky dispersal barriers (for walking insects). The nutritional and reproductive states of adults were evaluated. Over the course of the sampling period, a total of eight flying adults, six walking nymphs and 10 walking adults of the species T. infestans were captured, as well as specimens of Triatoma guasayana, Triatoma eratyrusiformis and Triatoma platensis. Our data demonstrate for the first time that females of T. infestans can disperse by walking. This may be an adaptive strategy because it allows them to move with eggs and/or with good blood reserves, which are not possible when flying. All flying and walking individuals of both genders were of an appropriate physiological state that would allow for colonisation of the target habitat. However, manual inspection of 122 chickens suggests that it is unlikely that these animals passively transport T. infestans. Finally, the dispersal activity of T. infestans was compared with other triatomines using a dispersion index.
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Coxiella burnetii is the agent of Q fever , an emergent worldwide zoonosis of wide clinical spectrum. Although C. burnetii infection is typically associated with acute infection, atypical pneumonia and flu-like symptoms, endocarditis, osteoarticular manifestations and severe disease are possible, especially when the patient has a suppressed immune system; however, these severe complications are typically neglected. This study reports the sequencing of the repetitive element IS1111 of the transposase gene of C. burnetii from blood and bronchoalveolar lavage (BAL) samples from a patient with severe pneumonia following methotrexate therapy, resulting in the molecular diagnosis of Q fever in a patient who had been diagnosed with active seronegative polyarthritis two years earlier. To the best of our knowledge, this represents the first documented case of the isolation of C. burnetii DNA from a BAL sample.
Resumo:
Schistosomiasis diagnosis is based on the detection of eggs in the faeces, which is laborious and lacks sensitivity, especially for patients with a low parasite burden. Immunological assays for specific antibody detection are available, but they usually demonstrate low sensitivity and/or specificity. In this study, two simple immunological assays were evaluated for the detection of soluble Schistosoma mansoni adult worm preparation (SWAP) and egg-specific IgGs. These studies have not yet been evaluated for patients with low parasite burdens. Residents of an endemic area in Brazil donated sera and faecal samples for our study. The patients were initially diagnosed by a rigorous Kato-Katz analysis of 18 thick smears from four different stool samples. The ELISA-SWAP was successful for human diagnosis with 90% sensitivity and specificity, confirming the Kato-Katz diagnosis with nearly perfect agreement, as seen by the Kappa index (0.85). Although the ELISA-soluble S. mansoni egg antigen was 85% sensitive, it exhibited low specificity (80%; Kappa index: 0.75) and was more susceptible to cross-reactivity. We believe that immunological assays should be used in conjunction with Kato-Katz analysis as a supplementary tool for the diagnosis of schistosomiasis for patients with low infection burdens, which are usually hard to detect.
Resumo:
Lipophorin (Lp) is the main haemolymphatic lipoprotein in insects and transports lipids between different organs. In adult females, lipophorin delivers lipids to growing oocytes. In this study, the interaction of this lipoprotein with the ovaries of Rhodnius prolixus was characterised using an oocyte membrane preparation and purified radiolabelled Lp (125I-Lp). Lp-specific binding to the oocyte membrane reached equilibrium after 40-60 min and when 125I-Lp was incubated with increasing amounts of membrane protein, corresponding increases in Lp binding were observed. The specific binding of Lp to the membrane preparation was a saturable process, with a Kdof 7.1 ± 0.9 x 10-8M and a maximal binding capacity of 430 ± 40 ng 125I-Lp/µg of membrane protein. The binding was calcium independent and pH sensitive, reaching its maximum at pH 5.2-5.7. Suramin inhibited the binding interaction between Lp and the oocyte membranes, which was completely abolished at 0.5 mM suramin. The oocyte membrane preparation from R. prolixus also showed binding to Lp from Manduca sexta. When Lp was fluorescently labelled and injected into vitellogenic females, the level of Lp-oocyte binding was much higher in females that were fed whole blood than in those fed blood plasma.
Resumo:
We present the study of the geochemical processes associated with the first successful remediation of a marine shore tailings deposit in a coastal desert environment (Bahia de Ite, in the Atacama Desert of Peru). The remediation approach implemented a wetland on top of the oxidized tailings. The site is characterized by a high hydrauliz gradient produced by agricultural irrigation on upstream gravel terraces that pushed river water (similar to 500 mg/L SO(4)) toward the sea and through the tailings deposit. The geochemical and isotopic (delta(2)H(water) and delta(18)O(water), delta(34)S(sulfate) , delta(18)O(sulfate)) approach applied here revealed that evaporite horizons (anhydrite and halite) in the gravel terraces are the source of increased concentrations of SO(4), Cl, and Na up to similar to 1500 mg/L in the springs at the base of the gravel terraces. Deeper groundwater interacting with underlying marine sequences increased the concentrations of SO(4), Cl, and Na up to 6000 mg/L and increased the alkalinity up to 923 mg/L CaCO(3) eq. in the coastal aquifer. These waters infiltrated into the tailings deposit at the shelf-tailings interface. Nonremediated tailings had a low-pH oxidation zone (pH 1-4) with significant accumulations of efflorescent salts (10-20 cm thick) at the surface because of upward capillary transport of metal cations in the arid climate. Remediated tailings were characterized by neutral pH and reducing conditions (pH similar to 7, Eh similar to 100 mV). As a result, most bivalent metals such as Cu, Zn, and Ni had very low concentrations (around 0.01 mg/L or below detection limit) because of reduction and sorption processes. In contrast, these reducing conditions increased the mobility of iron from two sources in this system: (1) The originally Fe(III)-rich oxidation zone, where Fe(II) was reduced during the remediation process and formed an Fe(II) plume, and (2) reductive dissolution of Fe(III) oxides present in the original shelf lithology formed an Fe-Mn plume at 10-m depth. These two Fe-rich plumes were pushed toward the shoreline where more oxidizing and higher pH conditions triggered the precipitation of Fe(HI)hydroxide coatings on silicates. These coatings acted as a filter for the arsenic, which naturally infiltrated with the river water (similar to 500 mu g/L As natural background) into the tailings deposit.
Resumo:
Deepening of affect in psychotherapy is a process that allows the patient to access more fully his/her affective experience linked to the problems. This process allows him/her to better understand this experience, aiming at a new understanding of himself/herself, the internal determinants of the problem and his/her reactions to difficult situations. Four clinical models treat this question by proposing different techniques aiming at deepening of affect in session: brief psychodynamic psychotherapy, clinical hypnosis, emotion-focused therapy, clarification-oriented psychotherapy as development of focusing. It appears that, despite diverse theoretical approaches, there exist several parallels throughout these approaches. We will summarize the research results supporting the hypothesis of affect deepening as an efficacious therapeutic process in different forms of exploratory psychotherapy. (C) 2009 Societe francaise de psychologie. Published by Elsevier Masson SAS. All rights reserved.
Resumo:
The incidence of over-education is here assessed by applying some standard subjective and objective indicators and a new skill-based indicator of over-education to the national samples of eight European countries in the REFLEX survey. With the exception of Spain, the results reveal that over-education is a minor risk amongst European tertiary graduates. Yet, the contrast between the standard indicators and the skill-based indicator reveals the existence of an over-education of a moderate kind in countries with high tertiary attainment rates (Norway, Finland and Netherlands). Such a type of over-education does not come to the surface when applying the standard indicators. Our results also reveal the importance of higher education differentiation (i.e. field of study and branch of higher education) for understanding the risk of over-education. Graduates from humanistic fields, bachelor courses and vocational colleges are more exposed to over-education, though their disadvantage varies across-nationally to a significant extent.
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Affective, cognitive and behavioral components affect nurses´ attitudes to include families in the care processes. The purpose of this study was to investigate the attitudes of nurses about the importance of including families in nursing care. Data collection was performed in pediatric and maternal-child unit of a Brazilian university hospital. A sample of 50 nurses completed the Portuguese version of the instrument Families’Importance in Nursing Care-Nurses’ Attitudes (FINC-NA). The results indicated that nurses have supportive attitudes regarding families participation in nursing care. Attitudes of lower support for involving families in nursing care were found among nurses with older age, more time in the profession and who had no previous contact with contents related to Family Nursing. The application of the instrument in other contexts of assistance may help to illuminate important aspects of the challenges to implementing a family-centered approach in clinical practice.
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The title of this thesis is “The importance of using games to teach English in the 3rd Cycle”. I choose this topic because I think that games are important in the process of learning and because in my opinion not only students but people in general are more motivated to learn when they are having fun or when they are doing something that is interesting. Some authors argue that games stimulate learners to practise, to activate and extend their English vocabulary, and that most students feel more motivated to learn and learn more easily when they are having fun. Games make demands on learners’ intelligence and imagination and calls for active participation. That is exactly what 3rd Cycle students and teachers need in order to have success in their studies and work respectively. The 3rd Cycle students have covered the majority of the grammar and functions contents of the English curriculum in the previous Cycles (the 1st and 2nd Cycle) and in the 3rd Cycle the students need most of their time to put into practice what they have learned before. Games are an effective method to put in practice what they have learned before and also through games they have several contexts and different situations to explore in order to show their knowledge or their vocabulary. The 3rd Cycle students need methods that motivate them to learn and to participate in class and since they already study a specific language function. If the teacher uses an enjoyable method like games students will not get bored and they will be more motivate to participate in class.
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We study the effect of providing relative performance feedback information onperformance, when individuals are rewarded according to their absolute performance. Anatural experiment that took place in a high school offers an unusual opportunity to testthis effect in a real-effort setting. For one year only, students received information thatallowed them to know whether they were performing above (below) the class average aswell as the distance from this average. We exploit a rich panel data set and find that theprovision of this information led to an increase of 5% in students grades. Moreover, theeffect was significant for the whole distribution. However, once the information wasremoved, the effect disappeared. To rule out the concern that the effect may beartificially driven by teachers within the school, we verify our results using nationallevel exams (externally graded) for the same students, and the effect remains.
Resumo:
We estimate four models of female labour supply using a Spanish sampleof married women from 1994, taking into account the complete form of theindividual s budget set. The models differ in the hypotheses relating tothe presence of optimisation errors and/or the way non-workers contributeto the likelihood function. According to the results, the effects of wagesand non-labour income on the labour supply of Spanish married women dependon the specification used. The model which has both preference andoptimisation errors and allows for both voluntarily and involuntarilyunemployed females desiring to participate seems to better fit the evidencefor Spanish married women.