Fructan variation in the rhizophores of Vernonia herbacea (Vell.) Rusby, as influenced by temperature

The influence of climatic variations on fructan content in tropical regions is not well known. The present study deals with the effects of temperature on fructan contents in rhizophores of plants of Vernonia herbacea, a native species from the Brazilian cerrado vegetation. Intact plants and fragmented rhizophores were subjected to different temperatures under natural and controlled environmental conditions. Rhizophores of plants in pre-dormant stage (aerial parts showing some yellowish leaves) presented higher fructan content at 5oC than those kept at 25oC, whereas in dormant plants (aerial parts absent) temperature treatments did not affect fructan contents. Fragmented rhizophores obtained from dormant plants presented higher levels of fructo-polysaccharides at the end of the experiment than at the beginning of the treatment, regardless of the temperature they were stored, whereas fragments obtained from vegetative plants showed a decrease in fructan content under the same treatments. It was concluded that variations observed in fructan contents are related to the phenological state of the plants prior to the treatment rather than to extraneous temperatures they are subjected to during this stage.

In vitro culture at low temperature and ex vitro acclimatization of Vriesea inflata an ornamental bromeliad

(In vitro culture at low temperature and ex vitro acclimatization of Vriesea inflata an ornamental bromeliad). In vitro culture by seeds is a technique for preservation of threatened species because it may provide a large number of plants with genetic diversity. The bromeliad Vriesea inflata (Wawra) Wawra, an ornamental bromeliad, is extensively and illegally collected from the nature and must be preserved. It is possible to form plant threatened collections in vitro by reducing the temperature of culture, while occupying little space, with the consequent reduction of maintenance costs. This work evaluated the influence of temperature on in vitro growth and morphology of plants of V. inflata, with the aim of establishing a slow growth-rate and analyzing the ex vitro acclimatization. Seeds were germinated in vitro in Murashige and Skoog (MS) medium, with macronutrients reduced to 50% (MS/2). After three months the plants were transferred to flasks of new same medium and kept in two germination chambers with the temperature adjusted to 15 °C and to 28 °C. After 24 months the plants were subject to biometric, photosynthetic pigments content and anatomical analyses. Results showed that plants maintained at 15 °C were smaller than those at 28 °C. Nevertheless, there were no alterations in pigments content, anatomy. In both treatments there was a survival rate of 100%. This work showed that plants of this species can be kept in vitro at 15 °C with the aim of forming a slow-growth collection, thereby seeking its preservation, and can be transferred to growth at ex vitro condition to achieved 100% survival rate.

Etiological drug treatment of human infection by Trypanosoma cruzi

Forty-nine American Trypanosomiasis (Chagas' disease) patients, with xenodiagnosis proven parasitemia were treated by the authors. Forty-one of these patients were given benznidazole, at dosages ranging from 5mg/kg/day to 8mg/kg/day, during a pre-established period of 60 days. In this group, 17 patients had an undetermined form of the disease, whereas 22 had cardiologic disease and 4 had digestive disease (two patients had a mixed form of the disease). Side effects were frequent, and led to the discontinuation of treatment in 17 patients. The follow-up period ranged from 1 to 20 years (mean follow-up period of 6 yrs. 7 mo). 26 (63.4%) of the patients became parasitemia-negative. The other eight patients were treated with nifurtimox, during 120 days, following a variable dose regime of 5mg/kg/day (initial dose) to 17 mg/kg/day (final dose). Six of them had severe side effects, and only one patient remained parasitemia-negative throughout the observation period (ranging from 1 to 18 years). Benznidazole proved to be better tolerated and more effective in the management of parasitemia when compared to nifurtimox, although more effective and less toxic drugs are still desirable.

Re-evaluation of the basic procedures involved in the storage of measles vaccine in public health units of the municipality of Niterói, state of Rio de Janeiro, Brazil

Four years after the first visit seventeen public health units were visited again and evaluated as to standards of storage recommended by the Brazilian Immunization Programme. In 100% of the units, refrigerators and proper inside location of vaccines in the refrigerator were adequatety or regularfy maintained and checked, respectively. However, when control of temperature was checked, onfy 64.7% presented adequate storage conditions. In 94.1 % of the units, health workers complained of lack of immediate technical support in emergency situations. In 55.2 % the titers vaccine samples of were under the minimal recommended potency. It is necessary that the factors concerning the cold chain be continualfy evaluated so that the quality of the vaccines that will be used is not affected.

Growth and differentiation on a trypanosome of the subgenus Schizotrypanum from the bat Phyllostomus hastatus

The effects of temperature, pH, osmolarity and aeration on the growth and differentiation of a trypanosome ofthe subgenus Schizotrypanum isolatedfrom the bat Phyllostomus hastatus were studied. In general, the growth characteristics ofthe flagellate were similar to those of Trypanosoma (Schizotrypanum) cruzi. However, the parasite did not growth at 33 or 37C. Increase in the osmolarity and aeration promoted growth at 33C. Significant metacyclogenesis was detected only in the growth condition where maximal growth occured (28C, pH 7.3, 380m0s/kg, in tissue cullure flasks), at the end ofthe exponential growth phase. The begining of the metacyclogenesis process was coincident with most glucose utilization and lowest pH. During metacyclogenesis both culture medium pH and osmolarity increased steadly.

Sensitivity of the Amazon biome to high resolution climate change projections

ABSTRACT: Despite the reduction in deforestation rate in recent years, the impact of global warming by itself can cause changes in vegetation cover. The objective of this work was to investigate the possible changes on the major Brazilian biome, the Amazon Rainforest, under different climate change scenarios. The dynamic vegetation models may simulate changes in vegetation distribution and the biogeochemical processes due to climate change. Initially, the Inland dynamic vegetation model was forced with initial and boundary conditions provided by CFSR and the Eta regional climate model driven by the historical simulation of HadGEM2-ES. These simulations were validated using the Santarém tower data. In the second part, we assess the impact of a future climate change on the Amazon biome by applying the Inland model forced with regional climate change projections. The projections show that some areas of rainforest in the Amazon region are replaced by deciduous forest type and grassland in RCP4.5 scenario and only by grassland in RCP8.5 scenario at the end of this century. The model indicates a reduction of approximately 9% in the area of tropical forest in RCP4.5 scenario and a further reduction in the RCP8.5 scenario of about 50% in the eastern region of Amazon. Although the increase of CO2 atmospheric concentration may favour the growth of trees, the projections of Eta-HadGEM2-ES show increase of temperature and reduction of rainfall in the Amazon region, which caused the forest degradation in these simulations.

Seasonal variability on the structure of sublittoral macrozoobenthic association in the Patos Lagoon estuary, southern Brazil

The aim of this study is to analyze and relate the spatial-temporal variability of macrozoobenthic assemblages to bottom characteristics and salinity fluctuations, in an estuarine shallow water region of Patos Lagoon. Monthly samples, between September 2002 and August 2003, were taken on six sampling stations (distant 90 m). Three biological samples with a 10 cm diameter corer, one sample for sediment analysis, fortnightly bottom topography measurements, and daily data of temperature and salinity were taken from each station. Two biotic and environmental conditions were identified: the first corresponding to spring and summer months, with low macrozoobenthos densities, low values of salinity, small variations in bottom topographic level and weak hydrodynamic activity. A second situation occurred in the months of fall and winter, which showed increased salinity, hydrodynamics and macrobenthos organisms. These results which contrast with previous studies carried out in the area, were attributed to failure in macrozoobenthos recruitments during summer period, especially of the bivalve Erodona mactroides Bosc, 1802 and the tanaid Kalliapseuses schubartii Mañe-Garzón, 1949. This results showed that recruitments of dominant species were influenced by salinity and hydrodynamic conditions.

Population fluctuations of calliphorid species (Diptera, Calliphoridae) in the Biological Reserve of Tinguá, state of Rio de Janeiro, Brazil

The purpose of this work was to determine the diversity and population fluctuations of calliphorid flies in the Biological Reserve of Tinguá (ReBio-Tinguá), Nova Iguaçu, state of Rio de Janeiro, Brazil and to correlate their occurrence with the environmental variables of temperature, rainfall and relative air humidity. Specimens of Diptera were collected monthly between June 2002 and January 2005 using four traps placed at four points along a trail and exposed for 48 hours. The traps were baited with sardines and the trapped insects were stored in 70% alcohol. It was collected 8,528 calliphorids, thirteen species were identified among the blowflies including Laneela nigripes Guimarães 1977, Chrysomya megacephala (Fabricius, 1794), C. albiceps (Wiedemann, 1819), C. putoria (Wiedemann, 1830), Chloroprocta idioidea (Robineau-Devoidy, 1830), Cochliomyia macellaria (Fabricius, 1775), Hemilucilia semidiaphana (Rondani, 1850), H. segmentaria (Fabricius, 1805), Lucilia eximia (Wiedemann,1819), L. cuprina (Wiedemann, 1830), Paralucilia pseudolyrcea (Mello, 1969), Mesembrinella sp. and Eumesembrinella pauciseta (Aldrich, 1922). No significant correlation was found between the abundance of blowflies and the temperature and relative air humidity. Only C. megacephala and C. albiceps showed a positive and significant correlation with rainfall. An analysis of grouping by month (UPGMA) revealed no seasonal difference in the composition of the community, indicating that the community of calliphorid flies is probably more influenced by the ecological niches occupied by each species than by the seasons of the year.

Temperature-sex determination in Podocnemis expansa (Testudines, Podocnemididae)

This study has been carried out at the central region of the Araguaia river on the border between the states of Goiás and Mato Grosso in the Brazilian Amazon Basin from September to December 2000. We recorded temperature fluctuation, clutch-size, incubation period and hatching success rate and hatchlings' sex ratio of five nests of Podocnemis expansa (Schweigger, 1812). Despite the relatively small sample size we infer that: a) nests of P. expansa in the central Araguaia river have a lower incubation temperature than nests located further south; however, incubation period is shorter, hatching success rate is lower and clutch-size is larger; b) Podocnemis expansa may present a female-male-female (FMF) pattern of temperature sex-determination (TSD); c) thermosensitive period of sex determination apparently occur at the last third of the incubation period; and, d) future studies should prioritize the relationship between temperature variation (i.e., range and cycle) and embryos development, survivorship and sex determination.

Lamella formation and emigration from the water by a laboratory colony of Biomphalaria glabrata (SAY) in flow-through system

Lamella formation and emigration from the water were investigated in juvenile Biomphalaria glabrata reared at two temperatures in aquaria with a constant water flow. Most snails (97.4%) reared at the lower temperature (21- C) formed lamella at the shell aperture and emigrated from the water, whereas only 10.1% did so at 25- C. Eighty percent of emigrations at 21- C occurred within a period of 15 days, 70-85 days after hatching. A comparison of the studies done so far indicates that the phenomenon may be affected by the ageing of snail colonies kept in the laboratory and their geographic origin, rather than the rearing conditions. This hypothesis, however, requires experimental confirmation.

Factors influencing predation of the Waterbugs Sphaerodema annulatum (Fab.) and S. rusticum (Fab.) on the Disease Transmitting Snail Lymnaea (Radix) luteola (Lamarck)

Variations in the rate of predation of the waterbugs Sphaerodema annulatum and S. rusticum on the snails Lymnaea (Radix) luteola have been noted in respect to the morphs of the waterbugs, size of the prey individuals, densities of prey and predators, temperature and surface area of the waterbody concerned and the seasons. Consumption rate was highest (7.2 and 2.2 individuals per day per individual of S. annulatum and S. rusticum, respectively) in prereproductive ages of the waterbugs. This was followed by a gradual decline with the increase in age of the predators. The consumption rate was gradually higher with the increase of temperature from 20 °C to 35 °C. The bugs failed to survive beyond 35 days at 35 °C. Though the bugs prey upon the snails of all sizes preference for 6.5 ÷ 4.5 mm to 8 ÷ 5 mm individuals by S. annulatum and for 5 ÷ 3 mm to 6.5 ÷ 4.5 mm individuals belonged to 3 ÷ 2 - 4 ÷ 3 mm size group maximum when supplied separately. The rate of predation gradually declined with the rise of predator's desity irrespective of waterbug species. Predation rate increased with increasing prey density. This was level off when the prey snails were 1100 and 700 in number for S. annulatum and S. rusticum respectively. An adult S. annulatum and S. rusticum consumed 5.04, 3.7, 1.43 and 3.36, 2.49, 1.04 snails per day respectively in summer, monsoon and winter.

Ecology of mosquitoes (Diptera: Culicidae) in areas of Serra do Mar State Park, State of São Paulo, Brazil. I - Monthly frequency and climatic factors

The ecology of mosquitoes were studied (Diptera: Culicidae) in areas of Serra do Mar State Park, State of São Paulo, Brazil. Systematized monthly human bait collections were made three times a day, for periods of 2 or 3 h each, in sylvatic and rural areas for 24 consecutive months (January 1991 to December 1992). A total of 24,943 specimens of adult mosquitoes belonging to 57 species were collected during 622 collective periods. Coquillettidia chrysonotum was the most frequent collected mosquito (45.8%) followed by Aedes serratus (6.8%), Cq. venezuelensis (6.5%), Psorophora ferox (5.2) and Ps. albipes (3.1%). The monthly averages of temperature and relative humidity were inserted in the ten-year average limits of maximum and minimum of the previous ten-years. Rainfall accompanied the curve of the ten-year averages. Those climatic factors were influential in the incidence of some species; temperature: Anopheles cruzii, An. mediopunctatus, Ae. scapularis, Ae. fulvus, Cq. chrysonotum, Cq. venezuelensis, Runchomyia reversa, Wyeomyia dyari, Wy. confusa, Wy. shannoni, Wy. theobaldi and Limatus flavisetosus; relative humidity: Ae. serratus, Ae. scapularis, Cq. venezuelensis and Ru. reversa; rainfall: An. cruzii, Ae. scapularis, Ae. fulvus, Cq. venezuelensis Ru. reversa, Wy. theobaldi and Li. flavisetosus.

Phlebotomine sand flies in Porteirinha, an area of American visceral leishmaniasis transmission in the State of Minas Gerais, Brazil

A study of the phlebotomine sand fly fauna was carried out in an endemic area of American visceral leishmaniasis (AVL) in the municipality of Porteirinha, in the Brazilian state of Minas Gerais. Captures were performed with CDC light traps in 7 districts, 5 days per month, during 2 consecutive years (January 2000 to December 2001). A total of 3240 sand flies were captured and identified. Sixteen species were found, among which 15 belonged to the genus Lutzomyia and one to the genus Brumptomyia. Lutzomyia longipalpis, a proven vector of AVL, was the predominant species (71.85%) throughout the time period. The interference of climatic factors (temperature, humidity, and rainfall) over the populational dynamics of the sand flies was determined. Statistical analysis of the data showed a significant correlation among the number of phlebotomine sand flies collected, rainfall, and humidity, whereas the effect of temperature was negligible, in that particular region. The amount of collected phlebotomine, the number of human cases, and the prevalence of canine AVL in the districts of Porteirinha are discussed.

Triatoma rubrovaria (Blanchard, 1843) (Hemiptera - Reduviidae - Triatominae) IV: bionomic aspects on the vector capacity of nymphs

Triatoma rubrovaria has become the most frequently captured triatomine species since the control of T. infestans in the state of Rio Grande do Sul (RS), Brazil. The aim of this study was to evaluate aspects of the vectorial competence of T. rubrovaria using nymphs raised in laboratory under environmental conditions of temperature and humidity and fed on mice. The average developmental period of T. rubrovaria was 180.1 days. The percentage of defecation shortly after feeding was still higher than previous studies in which samples of T. rubrovaria subjected to a slight starvation period before the blood meal were used. The obtained results support former indication that T. rubrovaria presents bionomic characteristics propitious to be a good vector of Trypanosoma cruzi to man. Therefore its domiciliary invasion process must be continuously monitored.

Laboratory estimation of the effects of increasing temperatures on the duration of gonotrophic cycle of Anopheles albimanus (Diptera: Culicidae)

The increase of malaria transmission in the Pacific Coast of Colombia during the occurrence of El Niño warm event has been found not to be linked to increases in the density of the vector Anopheles albimanus, but to other temperature-sensitive variables such as longevity, duration of the gonotrophic cycle or the sporogonic period of Plasmodium. The present study estimated the effects of temperature on duration of the gonotrophic cycle and on maturation of the ovaries of An. albimanus. Blood fed adult mosquitoes were exposed to temperatures of 24, 27, and 30°C, held individually in oviposition cages and assessed at 12 h intervals. At 24, 27, and 30°C the mean development time of the oocytes was 91.2 h (95% C.I.: 86.5-96), 66.2 h (61.5-70.8), and 73.1 h (64-82.3), respectively. The mean duration of the gonotrophic cycle for these three temperatures was 88.4 h (81.88-94.9), 75 h (71.4-78.7), and 69.1 h (64.6-73.6) respectively. These findings indicate that both parameters in An. albimanus are reduced when temperatures rose from 24 to 30°C, in a nonlinear manner. According to these results the increase in malaria transmission during El Niño in Colombia could be associated with a shortening of the gonotrophic cycle in malaria vectors, which could enhance the frequency of man-vector contact, affecting the incidence of the disease.