Control of Asian soybean rust with mancozeb, a multi-site fungicide

An experiment conducted in the field the action of mancozeb, a fungicide of multi-site action was tested, to control soybean rust caused by Phakopsora pachyrhizi. Its performance was compared to that of the mixture cyproconazole (DMI) + azoxystrobin (QoI). The soybean cultivar NA 7337 RR was used with a population of 400,000 plants/ha cultivated in 20m2 plots. Treatments consisted of mancozeb levels (1.5 and 2.0 kg/ha) applied four, six and eight times. The DMI + QoI mixture was applied three times at 0.3 L/ha + Nimbus. Rust severity was assessed six times in the plots and data were integrated as the area under the disease progress curve (AUDPC). The plots were harvested and grain yield was expressed as kg/ha. Data on AUDPC and yield were subjected to analysis of variance and means compared according to Turkey's test (p = 0.005). Treatments with mancozeb were superior to DMI + QoI mixture both for rust control and grain yield. Four applications of 2.0 k/ha mancozeb were more efficient than three applications of the mixture used as standard. Mancozeb has the potential to be added to fungicide mixtures in the establishment of soybean rust anti-resistance strategy.

Four whole-istic aspects of schistosome granuloma biology: fractal arrangement, internal regulation, autopoietic component and closure

This paper centers on some whole-istic organizational and functional aspects of hepatic Schistosoma mansoni granuloma, which is an extremely complex system. First, it structurally develops a collagenic topology, originated bidirectionally from an inward and outward assembly of growth units. Inward growth appears to be originated from myofibroblasts derived from small portal vessel around intravascular entrapped eggs, while outward growth arises from hepatic stellate cells. The auto-assembly of the growth units defines the three-dimensional scaffold of the schistosome granulomas. The granuloma surface irregularity and its border presented fractal dimension equal to 1.58. Second, it is internally regulated by intricate networks of immuneneuroendocrine stimuli orchestrated by leptin and leptin receptors, substance P and Vasoactive intestinal peptide. Third, it can reach the population of ± 40,000 cells and presents an autopoietic component evidenced by internal proliferation (Ki-67+ Cells), and by expression of c-Kit+ Cells, leptin and leptin receptor (Ob-R), granulocyte-colony stimulating factor (G-CSF-R), and erythropoietin (Epo-R) receptors. Fourth, the granulomas cells are intimately connected by pan-cadherins, occludin and connexin-43, building a state of closing (granuloma closure). In conclusion, the granuloma is characterized by transitory stages in such a way that its organized structure emerges as a global property which is greater than the sum of actions of its individual cells and extracellular matrix components.

Effect of dose and application site on quinclorac absorption by barnyardgrass biotypes

This work aimed to evaluate the uptake and translocation of quinclorac in function of application sites (shoot or roots) by Echinochloa crusgalli biotypes resistant and susceptible to this herbicide. The treatments consisted of quinclorac doses (0; 0.5; 1; 2; 4; 16 and 64 ppm), applied on the shoot or roots of seedlings of barnyardgrass biotypes. The experimental units consisted of plastic cups containing 250 cm³ of sand. The treatments were applied 10 days after emergence, when barnyardgrass plants reached a 2- to 3- leaf growth stage. The barnyardgrass biotypes were irrigated with nutritive solution weekly and maintained for 40 days after emergence, when length, fresh and dry matter of shoot and roots were evaluated. Variance analysis was carried out using the F test at 5% probability, and in case of significance, a non-linear regression analysis was also carried out using a three-parameter logistic model. In the susceptible biotype, quinclorac was more absorbed by the roots than by the shoot. Comparing dry mass production of the different plant parts of the susceptible biotype per application site, it was verified that quinclorac action is higher when applied to the plant roots. However, for the resistant biotype, it was not possible to determine the dose causing 50% reduction in dry mass accumulation (GR50) and in the resistance index (RI) between both biotypes, due to its high resistance to quinclorac (128 times the recommended dosage). The results showed that quinclorac resistance by the evaluated biotype is not due to differences in the absorption site, strongly suggesting that the resistance acquired by the biotype may result from alteration in the target site.

Affinity and diversity indices for anopheline immature forms

As for the entire Amazon Region, malaria continues to be a major health public problem in Roraima that presented an Annual Parasitic Index of 85.4 in 2005, the highest in Brazil. Information on anopheline breeding sites is an essential component in malaria control strategies. Aiming to contribute to the limited knowledge on anopheline immature forms in Roraima, collections and breeding site observations were performed in 10 breeding sites around the capital city Boa Vista. Collections were carried out in the rainy and dry season periods between April 2004 and January 2005. Breeding sites comprised natural and artificial water reservoirs. A total of 623 immature forms were collected belonging to Anopheles albitarsis s.l., An.triannulatus s.l., An. nuneztovari/dunhami, An. braziliensis, An. evansae, An. oswaldoi s.l., An. strodei and An. darlingi. An. albitarsis and An. braziliensis were the most frequently found species. Eight larvae of An. darlingi were found in only one breeding site located in the forest. An. triannulatus/An. nuneztovari and An. albitarsis/An. braziliensis were the pairs of species that mostly occurred together. Both pair of species displayed the highest affinity index what might indicate a high compatibility for the same breeding conditions and/or a synergistic co-occurrence. Species diversity index was higher for the dry season.

The hemolytic component of cancer anemia: effects of osmotic and metabolic stress on the erythrocytes of rats bearing multifocal inoculations of the Walker 256 tumor

Cancer anemia is classified as an anemia of chronic diseases, although it is sometimes the first symptom of cancer. Cancer anemia includes a hemolytic component, important in the terminal stage when even transfused cells are rapidly destroyed. The presence of a chronic component and the terminal complications of the illness limit studies of the hemolytic component. A multifocal model of tumor growth was used here to simulate the terminal metastatic dissemination stage (several simultaneous inoculations of Walker 256 cells). The hemolytic component of anemia began 3-4 days after inoculation in 100% of the rats and progressed rapidly thereafter: Hb levels dropped from 14.9 ± 0.02 to 8.7 ± 0.06 from days 7 to 11 (~5 times the physiologically normal rate in rats) in the absence of bleeding. The development of anemia was correlated (r2 = 0.86) with the development of other systemic effects such as anorexia. There was a significant decrease in the osmotic fragility of circulating erythrocytes: the NaCl concentration causing 50% lysis was reduced from 4.52 ± 0.06 to 4.10 ± 0.01 (P<0.01) on day 7, indicating a reduction in erythrocyte volume. However, with mild metabolic stress (4-h incubation at 37oC), the erythrocytes showed a greater increase in osmotic fragility than the controls, suggesting marked alteration of erythrocyte homeostasis. These effects may be due to primary plasma membrane alterations (transport and/or permeability) and/or may be secondary to metabolic changes. This multifocal model is adequate for studying the hemolytic component of cancer anemia since it is rapid, highly reproducible and causes minimal animal suffering.

Regional governance: strategies and disputes in health region management

OBJECTIVE To analyze the regional governance of the health systemin relation to management strategies and disputes.METHODOLOGICAL PROCEDURES A qualitative study with health managers from 19 municipalities in the health region of Bahia, Northeastern Brazil. Data were drawn from 17 semi-structured interviews of state, regional, and municipal health policymakers and managers; a focus group; observations of the regional interagency committee; and documents in 2012. The political-institutional and the organizational components were analyzed in the light of dialectical hermeneutics.RESULTS The regional interagency committee is the chief regional governance strategy/component and functions as a strategic tool for strengthening governance. It brings together a diversity of members responsible for decision making in the healthcare territories, who need to negotiate the allocation of funding and the distribution of facilities for common use in the region. The high turnover of health secretaries, their lack of autonomy from the local executive decisions, inadequate technical training to exercise their function, and the influence of party politics on decision making stand as obstacles to the regional interagency committee’s permeability to social demands. Funding is insufficient to enable the fulfillment of the officially integrated agreed-upon program or to boost public supply by the system, requiring that public managers procure services from the private market at values higher than the national health service price schedule (Brazilian Unified Health System Table). The study determined that “facilitators” under contract to health departments accelerated access to specialized (diagnostic, therapeutic and/or surgical) services in other municipalities by direct payment to physicians for procedure costs already covered by the Brazilian Unified Health System.CONCLUSIONS The characteristics identified a regionalized system with a conflictive pattern of governance and intermediate institutionalism. The regional interagency committee’s managerial routine needs to incorporate more democratic devices for connecting with educational institutions, devices that are more permeable to social demands relating to regional policy making.

Low genetic diversity in Wolbachia-Infected Culex quinquefasciatus (Diptera: Culicidae) from Brazil and Argentina

Culex quinquefasciatus is a vector of human pathogens, including filarial nematodes and several viruses. Although its epidemiological relevance is known to vary across geographical regions, an understanding of its population genetic structure is still incipient. In light of this, we evaluated the genetic diversity of Cx. quinquefasciatus and Cx. pipiens x Cx. quinquefasciatus hybrids collected from nine localities in Brazil and one site in Argentina. We used mitochondrial genes cox1 and nd4, along with the coxA and wsp genes of the maternally-inherited Wolbachia endosymbiont. The nd4 fragment was invariant between samples, whilst cox1 exhibited four haplotypes that separated two types of Cx. quinquefasciatus, one clustered in southern Brazil. Low sequence diversity was generally observed, being discussed. Both Brazilian and Argentinian mosquitoes were infected with a single Wolbachia strain. As reported in previous studies with these populations, cox1 and nd4 diversity is not congruent with the population structure revealed by nuclear markers or alar morphology. Future Cx. quinquefasciatus research should, if possible, evaluate mtDNA diversity in light of other markers.

Comparative study of survivor and nonsurvivor sepsis patients in a university hospital

To determine parameters associated with the evolution of sepsis, a five-year retrospective study was conducted in a university hospital. One hundred and four consecutive sepsis patients were evaluated, of whom 55.8% were men. The mortality was 68.3% and was associated with older age (p<0.05). Chronic comorbidities and infection site were not associated with prognosis. Gram-positive bacteria were more frequently identified in survivors (p<0.05), while non-detection of the germ was associated with mortality (p<0.01). Appropriate use of antibiotics (germ sensitive to at least one drug administered) was associated with survival (p<0.0001) while inappropriate use (p<0.05) or empirical use (p<0.01) were more frequent in nonsurvivors. Leukocytosis was the main abnormality (54.8%) detected on diagnosis, from the leukocyte count. During the evolution, normal leukocyte count was associated with survival (p<0.01) and leukocytosis with mortality (p<0.05). In conclusion, mortality was associated with nondetection of the pathogen, leukocytosis during the evolution of the sepsis and inappropriate or empirical use of antimicrobials. Evidence-based treatment that is directed towards modifiable risk factors might improve the prognosis for sepsis patients.

Structure and composition of the ground-herb community in a terra-firme Central Amazonian forest

The herb community of tropical forests is very little known, with few studies addressing its structure quantitatively. Even with this scarce body of information, it is clear that the ground herbs are a rich group, comprising 14 to 40% of the species found in total species counts in tropical forests. The present study had the objective of increasing the knowledge about the structure and composition of the ground-herb community and to compare the sites for which there are similar studies. The study was conducted in a tropical non-inundated and evergreen forest 90 km north of Manaus, AM. Ground herbs were surveyed in 22 transects of 40 m², distributed in five plots of 4 ha. The inventoried community was composed of 35 species, distributed in 24 genera and 18 families. Angiosperms were represented by 8 families and Pteridophytes by 10 families. Marantaceae (12 sp) and Cyperaceae (4 sp) were the richest families. Marantaceae and Poaceae were the families with greatest abundance and cover. Marantaceae, Poaceae, Heliconiaceae and Pteridophytes summed 96% of total herb cover, and therefore were responsible for almost all the cover of the community. The 10 most important species had 83.7% of the individuals. In general, the most abundant species were also the most frequent. Richness per transect varied from 7 to 19 species, and abundance varied from 30 to 114 individuals. The community structure was quite similar to 3 other sites in South America and one site in Asia.

Chemical and physical attributes and calcium, magnesium, potassium, and phosphorus in the soil of murundu fields in Brazil

Fields of murundus (FM) are wetlands that provide numerous ecosystem services. The objectives of this study were to evaluate the chemical [organic carbon (OC), P, K+, Ca2+, Mg2+, Al3+ and H+Al] and physical [texture and bulk density (Bd)] soil attributes and calculate the organic matter (OM) and nutrient stock (P, Ca, Mg, and K) in soils of FM located in the Guapore River basin in Mato Grosso. Thirty-six sampling points were selected, and soil samples were collected from two environments: the murundu and plain area surrounding (PAS). At each sampling point, mini trenches of 0.5 × 0.5 × 0.4 m were opened and disturbed and undisturbed soil samples were collected at depths of 0-0.1, 0.1-0.2, and 0.2-0.4 m. In the Principal Component Analysis the variables H+Al (49%) and OM (4%) were associated with the F1 component and sand content (47%) with the F2 component. The FM had lower pH values and higher concentrations of K+, P, and H+Al than PAS at all depths (p < 0.05). Additionally, FM stocked up to 433, 360, 205, and 11 kg ha-1 of Ca, Mg, K, and P, respectively, for up to a depth of 0.2 m. The murundu stored two times more K and three times more P than that in the PAS. Our results show that the FM has high sand content and Bd greater than 1.5 Mg m-3, high acidity, low OC content, and low nutrient concentrations. Thus, special care must be taken to preserve FM such that human intervention does not trigger environmental imbalances.

Adult abundance, biting behavior and parity of Anopheles aquasalis, Curry 1932 in two malarious areas of Sucre State, Venezuela

The principal vector of malaria in eastern Venezuela, Anopheles aquasalis, is exophagic and exophilic. Control using indoor insecticide house sprays has failed to lower the number of malaria cases. Therefore, studies were initiated in two villages of the eastern coastal state of Sucre to better understand this vector's biology and develop a more integrated control program. An. aquasalis was found to have a crepuscular biting behavior with a major peak at dusk and a minor peak at dawn. Mosquitos were collected more outdoors than indoors. Forty-seven percent of the biting took place before people went to bed (22:30 hr) and 69% of the mosquitos biting during this time period bite outdoors. Outdoor biting could be the reason why indoor spraying alone did not lower malaria cases. Seasonal abundance was greater in the rainy season compared to the dry season. Seasonal parous rates were high (78.3%-100%) and similar indoors and outdoors and between dry and wet season in Santa F e. In Guayana, the seasonal parity was lower (34.6%-42.2%) than Santa F e with indoor parity slightly higher than outdoors. Malaria cases were higher in Santa F e, but adult mosquito density was much lower than in Guayana. This difference could have been due to higher parity in Santa F e compared to Guayana. The greater distance to the nearest breeding site and presence of alternative hosts in Guayana can not be discounted as factors which contributed to the difference in malaria transmission between locations. We concluded that knowledge on seasonal occurrence, biting activity, resting behavior and breeding site location can be used to design a new control strategy for this vector.

Evaluation of respiratory model employing conventional NIH mice to access the immunity induced by cellular and acellular pertussis vaccines

The increasing number of pertussis cases reported on the last twenty years and the existence of new acellular vaccines reinforce the need of research for experimental models to assure the quality of available pertussis vaccines. In this study, allotments of whole-cell and acellular pertussis vaccines were tested through the Intranasal Challenge Model (INM) using conventional NIH mice. The results have been compared to those achieved by the "Gold standard" Intracerebral Challenge Model (ICM). In contrast to ICM, INM results did not show intralaboratorial variations. Statistical analysis by Anova and Ancova tests revealed that the INM presented reproducibility and allowed identification and separation of different products, including three-component and four-component accellular pertussis vaccines. INM revealed differences between pertussis vaccines. INM provides lower distress to the mice allowing the reduction of mice number including the possibility of using conventional mice (less expensive) under non-aseptic environment. Thus, INM may be used as an alternative method of verifying the consistence of allotment production, including acellular pertussis vaccines.

Bacteria diversity and microbial biomass in forest, pasture and fallow soils in the southwestern Amazon basin

It is well-known that Amazon tropical forest soils contain high microbial biodiversity. However, anthropogenic actions of slash and burn, mainly for pasture establishment, induce profound changes in the well-balanced biogeochemical cycles. After a few years the grass yield usually declines, the pasture is abandoned and is transformed into a secondary vegetation called "capoeira" or fallow. The aim of this study was to examine how the clearing of Amazon rainforest for pasture affects: (1) the diversity of the Bacteria domain evaluated by Polymerase Chain Reaction and Denaturing Gradient Gel Electrophoresis (PCR-DGGE), (2) microbial biomass and some soil chemical properties (pH, moisture, P, K, Ca, Mg, Al, H + Al, and BS), and (3) the influence of environmental variables on the genetic structure of bacterial community. In the pasture soil, total carbon (C) was between 30 to 42 % higher than in the fallow, and almost 47 % higher than in the forest soil over a year. The same pattern was observed for N. Microbial biomass in the pasture was about 38 and 26 % higher than at fallow and forest sites, respectively, in the rainy season. DGGE profiling revealed a lower number of bands per area in the dry season, but differences in the structure of bacterial communities among sites were better defined than in the wet season. The bacterial DNA fingerprints in the forest were stronger related to Al content and the Cmic:Ctot and Nmic:Ntot ratios. For pasture and fallow sites, the structure of the Bacteria domain was more associated with pH, sum of bases, moisture, total C and N and the microbial biomass. In general microbial biomass in the soils was influenced by total C and N, which were associated with the Bacteria domain, since the bacterial community is a component and active fraction of the microbial biomass. Results show that the genetic composition of bacterial communities in Amazonian soils changed along the sequence forest-pasture-fallow.

Multivariate analysis and geostatistics of the fertility of a humic rhodic hapludox under coffee cultivation

The spatial variability of soil and plant properties exerts great influence on the yeld of agricultural crops. This study analyzed the spatial variability of the fertility of a Humic Rhodic Hapludox with Arabic coffee, using principal component analysis, cluster analysis and geostatistics in combination. The experiment was carried out in an area under Coffea arabica L., variety Catucai 20/15 - 479. The soil was sampled at a depth 0.20 m, at 50 points of a sampling grid. The following chemical properties were determined: P, K+, Ca2+, Mg2+, Na+, S, Al3+, pH, H + Al, SB, t, T, V, m, OM, Na saturation index (SSI), remaining phosphorus (P-rem), and micronutrients (Zn, Fe, Mn, Cu and B). The data were analyzed with descriptive statistics, followed by principal component and cluster analyses. Geostatistics were used to check and quantify the degree of spatial dependence of properties, represented by principal components. The principal component analysis allowed a dimensional reduction of the problem, providing interpretable components, with little information loss. Despite the characteristic information loss of principal component analysis, the combination of this technique with geostatistical analysis was efficient for the quantification and determination of the structure of spatial dependence of soil fertility. In general, the availability of soil mineral nutrients was low and the levels of acidity and exchangeable Al were high.

Phosphorus accumulation and pollution potential in a hapludult fertilized with pig manure

Successive applications of pig litter to the soil surface can increase the phosphorus (P) content and alter its adsorption, promoting P transfer to surface or subsurface waters. The purpose of this study was to evaluate P accumulation and the pollution potential of a soil after application of pig litter. In March 2010, eight years after the installation of an experiment in Braço do Norte, Santa Catarina, SC, Brazil, on a Typic Hapludult, soil was sampled (layers 0-2.5, 2.5-5, 5-10, 10-15, 15-20 and 20-30 cm) after the following fertilization treatments: no pig litter fertilization, pig slurry application and pig manure application. In this period, 694 and 1,890 kg P2O5 ha-1 were applied in the treatments with pig slurry and pig manure, respectively. The P content was determined, based on Mehlich-1, anion exchange resin (AER), 0.01 mol L-1 CaCl2 and total P in the samples. The adsorption isotherm parameters were also determined by the Langmuir and Koski-Vähälä & Hartikainem models in the layers 0-2.5 and 20-30 cm. The application of 1,890 kg P2O5 ha-1 in the form of pig manure led to P accumulation, as evidenced by Mehlich-1, down to a depth of 15 cm, by AER and 0.01 mol L-1 CaCl2 down to 20 cm and by total P to 30 cm. After application of 1,890 kg P2O5 ha-1 in the form of pig manure, the values of maximum P adsorption capacity were lowest in the deepest layer (20-30 cm), indicating the occupation of part of the adsorption sites of the particles. The application of swine manure to the soil over eight years increased the P quantity in the soil solution of the surface layer, indicating environmental contamination risk for surface and subsurface waters.