12 resultados para Two time scale

em Scielo Saúde Pública - SP


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The soft scale Cryptostigma urichi (Cockerell, 1894) and the mealybug Farinococcus multispinosus Morrison, 1922 are reported cohabiting inside branches of Anadenanthera falcata (Benth.) Speg. (Angico-preto), both tended by the ant Azteca oecocordia Longino, 2007 (Hymenoptera, Formicidae). This interaction was observed in the Cerrado region sensu stricto, at the Federal University of São Carlos, UFSCar, Brazil. A. oecocordia is recorded for the first time in Brazil.

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The objective of this paper is to propose a protocol to analyze blood samples in yellow fever 17DD vaccinated which developed serious adverse events. We investigated whether or not the time between sample collection and sample processing could interfere in lymphocyte subset percentage, for it is often impossible to analyze blood samples immediately after collection due to transport delay from collection places to the flow cytometry facility. CD4+CD38+ T, CD8+CD38+ T, CD3+ T, CD19+ B lymphocyte subsets were analyzed by flow cytometry in nine healthy volunteers immediately after blood collection and after intervals of 24 and 48 h. The whole blood lysis method and gradient sedimentation by Histopaque were applied to isolate peripheral blood mononuclear cells for flow cytometry analyses. With the lysis method, there was no significant change in lymphocyte subset percentage between the two time intervals (24 and 48 h). In contrast, when blood samples were processed by Histopaque gradient sedimentation, time intervals for sample processing influenced the percentage in T lymphocyte subsets but not in B cells. From the results obtained, we could conclude that the whole blood lysis method is more appropriate than gradient sedimentation by Histopaque for immunophenotyping of blood samples collected after serious adverse events, due to less variation in the lymphocyte subset levels with respect to the time factor.

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This work was carried out with the objective of evaluating the growth and development of honey weed (Leonurus sibiricus) based on days or thermal units (growing degree days). Thus, two independent trials were developed to quantify the phenological development and total dry mass accumulation in increasing or decreasing photoperiod conditions. Considering only one growing season, honey weed phenological development was perfectly fit to day scale or growing degree days, but with no equivalence between seasons, with the plants developing faster at increasing photoperiods, and flowering 100 days after seeding. Even day-time scale or thermal units were not able to estimate general honey weed phenology during the different seasons of the year. In any growing condition, honey weed plants were able to accumulate a total dry mass of over 50 g per plant. Dry mass accumulation was adequately fit to the growing degree days, with highlights to a base temperature of 10 ºC. Therefore, a higher environmental influence on species phenology and a lower environmental influence on growth (dry mass) were observed, showing thereby that other variables, such as the photoperiod, may potentially complement the mathematical models.

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This work was carried out with the objective of evaluating growth and development of sourgrass (Digitaris insularis) based on days or thermal units (growing degree days - GDD). Two independent trials were developed aiming to quantify the species' phenological development and total dry matter accumulation in increasing or decreasing photoperiod conditions. Plants were grown in 4 L plastic pots, filled with commercial substrate, adequately fertilized. In each trial, nine growth evaluations were carried out, with three replicates. Phenological development of sourgrass was correctly fit to time scale in days or GDD, through linear equation of first degree. Sourgrass has slow initial growth, followed by exponential dry matter accumulation, in increasing photoperiod condition. Maximum total dry matter was 75 and 6 g per plant for increasing and decreasing photoperiod conditions, respectively. Thus, phenological development of sourgrass may be predicted by mathematical models based on days or GDD; however, it should be noted that other environmental variables interfere on the species' growth (mass accumulation), especially photoperiod.

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Synchronization in the events of the reproductive cycle in female Neohelice granulata Dana, 1851 were studied from samples taken weekly and biweekly from September to December 2006 in the Laguna Mar Chiquita. The timing and larval hatching and synchronicity were inferred from numbers of ovigerous females and observing the stages of embryonic development. Synchronization in larval hatching also was observed in females in experiments in dark for a period of 48 hours, at three different salinities (10, 23 and 33 ppm). In addition plankton sampling were performed in order to study larval exportation at the field and its link to the tidal and light/dark cycles. We found that ovigerous females of N. granulata have a marked synchronization in embryonic development which results in that most of berried females are close to hatching within a period of maximum tidal range (days). Within this period, there is a synchronization of hatching at a time scale of hours, governed by environmental conditions. The salinity range used in this study (10-32‰) did not affect hatching synchronicity neither time to hatch. Hatching was synchronized according to endogenous rhythms governed mainly by the tidal cycle and secondarily by the breadth of it. It is also conditioned by the light-dark cycle through an exogenous cycle, so that the hatchings would occur mostly at night high tides.

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The genetic diversity displayed by Plasmodium falciparum, the most deadly Plasmodium species, is a significant obstacle for effective malaria vaccine development. In this study, we identified genetic polymorphisms in P. falciparum glutamate-rich protein (GLURP), which is currently being tested in clinical trials as a malaria vaccine candidate, from isolates found circulating in the Brazilian Amazon at variable transmission levels. The study was performed using samples collected in 1993 and 2008 from rural villages situated near Porto Velho, in the state of Rondônia. DNA was extracted from 126 P. falciparum-positive thick blood smears using the phenol-chloroform method and subjected to a nested polymerase chain reaction protocol with specific primers against two immunodominant regions of GLURP, R0 and R2. Only one R0 fragment and four variants of the R2 fragment were detected. No differences were observed between the two time points with regard to the frequencies of the fragment variants. Mixed infections were uncommon. Our results demonstrate conservation of GLURP-R0 and limited polymorphic variation of GLURP-R2 in P. falciparum isolates from individuals living in Porto Velho. This is an important finding, as genetic polymorphisms in B and T-cell epitopes could have implications for the immunological properties of the antigen.

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Eucalyptus Shoot Blight in the Vale do Rio Doce (ESBVRD) is an anomaly that leads to reduced growth and, in more extreme cases, to death of eucalyptus plants. Initially diagnosed in plantations in the region of the Vale do Rio Doce, in the State of Minas Gerais, Brazil, this problem has also been found in plantations in other regions of the country and even in other countries. Although the symptoms of this anomaly are well-known, its causes are not yet understood. The aim of this study was to evaluate the cause-effect relationship between accumulation of manganese (Mn) in eucalyptus clones and ESBVRD. Characterization of the environment in areas of greater occurrence of this problem in regard to soil, climate and fluctuation of the water table was undertaken in eucalyptus plantations of the Celulose Nipo-brasileira S.A. (Cenibra) company in the region of the Vale do Rio Doce. Plant tissues were sampled in two situations. In the first situation, diagnosis occurred in the initial phase of the anomaly in clones with differentiated tolerance to the problem; in the second situation, diagnosis was made in a single clone, considered to be sensitive, in two time periods - in the phase with the strong presence of symptoms and in the recovery phase, in areas of occurrence and in areas of escape from the problem. The most ESBVRD-sensitive clone showed much higher (4.8 times higher) leaf Mn contents than more tolerant clones. In plants with the anomaly, Mn leaf contents were greater than 3,070 mg kg-1, much greater than the quantity found in those without the anomaly (734 mg kg-1). In the period in which the symptoms began to wane, there was a sharp decline in leaf Mn contents, from 2,194 to 847 mg kg-1. Manganese content in the above ground part and plant litter (44.4 g ha-1) in the area of occurrence of the anomaly was three times greater than that found in these same components (14.1 g ha-1) in the area of absence of the symptom. Based on the evidence found, such as the existence of environmental conditions favorable to high Mn availability to the plants in the areas of greatest incidence of ESBVRD, greater uptake of Mn in sensitive clones and in plants with symptoms, and a synchronism between the intensity of symptoms of ESBVRD and leaf Mn contents, it may be inferred that temporary excess of Mn in eucalyptus plants is closely related to ESBVRD.

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The marine environment is certainly one of the most complex systems to study, not only because of the challenges posed by the nature of the waters, but especially due to the interactions of physical, chemical and biological processes that control the cycles of the elements. Together with analytical chemists, oceanographers have been making a great effort in the advancement of knowledge of the distribution patterns of trace elements and processes that determine their biogeochemical cycles and influences on the climate of the planet. The international academic community is now in prime position to perform the first study on a global scale for observation of trace elements and their isotopes in the marine environment (GEOTRACES) and to evaluate the effects of major global changes associated with the influences of megacities distributed around the globe. This action can only be performed due to the development of highly sensitive detection methods and the use of clean sampling and handling techniques, together with a joint international program working toward the clear objective of expanding the frontiers of the biogeochemistry of the oceans and related topics, including climate change issues and ocean acidification associated with alterations in the carbon cycle. It is expected that the oceanographic data produced this coming decade will allow a better understanding of biogeochemical cycles, and especially the assessment of changes in trace elements and contaminants in the oceans due to anthropogenic influences, as well as its effects on ecosystems and climate. Computational models are to be constructed to simulate the conditions and processes of the modern oceans and to allow predictions. The environmental changes arising from human activity since the 18th century (also called the Anthropocene) have made the Earth System even more complex. Anthropogenic activities have altered both terrestrial and marine ecosystems, and the legacy of these impacts in the oceans include: a) pollution of the marine environment by solid waste, including plastics; b) pollution by chemical and medical (including those for veterinary use) substances such as hormones, antibiotics, legal and illegal drugs, leading to possible endocrine disruption of marine organisms; and c) ocean acidification, the collateral effect of anthropogenic emissions of CO2 into the atmosphere, irreversible in the human life time scale. Unfortunately, the anthropogenic alteration of the hydrosphere due to inputs of plastics, metal, hydrocarbons, contaminants of emerging concern and even with formerly "exotic" trace elements, such us rare earth elements is likely to accelerate in the near future. These emerging contaminants would likely soon present difficulties for studies in pristine environments. All this knowledge brings with it a great responsibility: helping to envisage viable adaptation and mitigation solutions to the problems identified. The greatest challenge faced by Brazil is currently to create a framework project to develop education, science and technology applied to oceanography and related areas. This framework would strengthen the present working groups and enhance capacity building, allowing a broader Brazilian participation in joint international actions and scientific programs. Recently, the establishment of the National Institutes of Science and Technology (INCTs) for marine science, and the creation of the National Institute of Oceanographic and Hydrological Research represent an exemplary start. However, the participation of the Brazilian academic community in the latest assaults on the frontier of chemical oceanography is extremely limited, largely due to: i. absence of physical infrastructure for the preparation and processing of field samples at ultra-trace level; ii. limited access to oceanographic cruises, due to the small number of Brazilian vessels and/or absence of "clean" laboratories on board; iii. restricted international cooperation; iv. limited analytical capacity of Brazilian institutions for the analysis of trace elements in seawater; v. high cost of ultrapure reagents associated with processing a large number of samples, and vi. lack of qualified technical staff. Advances in knowledge, analytic capabilities and the increasing availability of analytical resources available today offer favorable conditions for chemical oceanography to grow. The Brazilian academic community is maturing and willing to play a role in strengthening the marine science research programs by connecting them with educational and technological initiatives in order to preserve the oceans and to promote the development of society.

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The aim of this study was to isolate microorganisms that produce lipase and to assess the efficiency of COD removal intreatment of cheese whey under different operating conditions. The microorganisms were isolated from cheese whey and a commercial product; it was selectedthreemicroorganisms that obtained the best response to the lipolytic activity test through the enzyme index. Then, the microorganisms were inoculated in sterilized cheese whey samples, for two pH values (6.2 and 7.0), incubated at 35 °C and 150 rpm in shaker and the lipolityc activity and the efficiency of COD removal were measured in two time periods (24 and 48h). After incubation, it was observed that the treatments showed a good removal efficiency of COD for the pre-treatment and the isolated microorganism (S1) from the cheese whey showed the highest lipase production. Regarding the pH and time variables, there was not significant effect between the two evaluated factors. Among all treatments, T2 (S1, pH 7.0 and 24h) obtained more enzyme production (4.87 U mL-1).

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Aiming at contributing to an adequate management of water resources, this study aimed to analyze and compare evapotranspiration (ETc) and crop coefficients (Kc) of melon plants measured by a lysimeter and estimated according to the FAO 56 methodology, in the city of Mossoró, state of Rio Grande do Norte (RN), Brazil. In order to measure ETc, weighing lysimeters with an area of 2.25m² were used, with two repetitions. The Penman-Monteith equation parameterized by FAO was used to estimate the reference evapotranspiration, and crop coefficients were those recommended in FAO-56 Bulletin adjusted to local climatic conditions. The required climatic data and lysimeter measurements were collected by an automatic weather station installed at the site. The results were compared by means of statistical indicators: of precision (r), of accuracy (d), and performance (c), in daily and weekly intervals. The data estimated by the FAO 56 methodology were adjusted optimally to the values measured by the lysimeters in accordance with index "c" in the two time scales assessed, indicating the potential of the method proposed by FAO to irrigation management in the climatic conditions of Agripole Assú-Mossoró.

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Hydrological models are important tools that have been used in water resource planning and management. Thus, the aim of this work was to calibrate and validate in a daily time scale, the SWAT model (Soil and Water Assessment Tool) to the watershed of the Galo creek , located in Espírito Santo State. To conduct the study we used georeferenced maps of relief, soil type and use, in addition to historical daily time series of basin climate and flow. In modeling were used time series corresponding to the periods Jan 1, 1995 to Dec 31, 2000 and Jan 1, 2001 to Dec 20, 2003 for calibration and validation, respectively. Model performance evaluation was done using the Nash-Sutcliffe coefficient (E NS) and the percentage of bias (P BIAS). SWAT evaluation was also done in the simulation of the following hydrological variables: maximum and minimum annual daily flowsand minimum reference flows, Q90 and Q95, based on mean absolute error. E NS and P BIAS were, respectively, 0.65 and 7.2% and 0.70 and 14.1%, for calibration and validation, indicating a satisfactory performance for the model. SWAT adequately simulated minimum annual daily flow and the reference flows, Q90 and Q95; it was not suitable in the simulation of maximum annual daily flows.

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The behavior of Petrov-Galerkin formulations for shallow water wave equations is evaluated numerically considering typical one-dimensional propagation problems. The formulations considered here use stabilizing operators to improve classical Galerkin approaches. Their advantages and disadvantages are pointed out according to the intrinsic time scale (free parameter) which has a particular importance in this kind of problem. The influence of the Courant number and the performance of the formulation in dealing with spurious oscillations are adressed.