Population dynamics of Triatoma vitticeps (Stål, 1859) in Itanhomi, Minas Gerais, Brazil

Taxonomic markers (head structure morphometry, isoenzymes and randon amplified polymorphism of DNA - RAPD) were used to understand the population dynamics of Triatoma vitticeps, predominant triatomine species in Itanhomi district, using samples obtained from domestic, peridomiciliary and sylvatic habitats. Morphometric analysis revealed sexual dimorphism within the three samples although specimens could not be separated according to the habitat in which they were captured. Forty-two bands were analyzed from RAPD profiles generated using four primers. A dendrogram constructed from Dice's similarity coefficient values showed that migration of the insects between the habitats has occurred, without structuring of populations. Moreover, the dendrogram obtained from the genetic distance values showed an important gene flow between the sylvatic and domestic habitats. No polymorphism was found in the electrophoretic mobility of proteins for the ten enzymes studied. Our results revealed movement of triatomines between the three habitats, suggesting that the presence of T. vitticeps in houses should not be ignored. As invasion of houses by sylvatic insects is frequent and the natural infection indices of this species are among the highest known, epidemiological vigilance studies may reveal possible changes in T. vitticeps behaviour which could present future risks to public health.

Seasonal dynamics of Aedes aegypti (Diptera: Culicidae) in the northernmost state of Brazil: a likely port-of-entry for dengue virus 4

Roraima is the northernmost state of Brazil, bordering both Venezuela and Guyana. Appropriate climate and vector conditions for dengue transmission together with its proximity to countries where all four dengue serotypes circulate make this state, particularly the capital Boa Vista, strategically important for dengue surveillance in Brazil. Nonetheless, few studies have addressed the population dynamics of Aedes aegypti in Boa Vista. In this study, we report temporal and spatial variations in Ae. aegypti population density using ovitraps in two highly populated neighbourhoods; Centro and Tancredo Neves. In three out of six surveys, Ae. aegypti was present in more than 80% of the sites visited. High presence levels of this mosquito suggest ubiquitous human exposure to the vector, at least during part of the year. The highest infestation rates occurred during the peak of the rainy seasons, but a large presence was also observed during the early dry season (although with more variation among years). Spatial distribution of positive houses changed from a sparse and local pattern to a very dense pattern during the dry-wet season transition. These results suggest that the risk of dengue transmission and the potential for the new serotype invasions are high for most of the year.

Experimental chemotherapy for Chagas disease: 15 years of research contributions from in vivo and in vitro studies

Chagas disease, which is caused by the intracellular parasite Trypanosoma cruzi, is a neglected illness with 12-14 million reported cases in endemic geographic regions of Latin America. While the disease still represents an important public health problem in these affected areas, the available therapy, which was introduced more than four decades ago, is far from ideal due to its substantial toxicity, its limited effects on different parasite stocks, and its poor activity during the chronic phase of the disease. For the past 15 years, our group, in collaboration with research groups focused on medicinal chemistry, has been working on experimental chemotherapies for Chagas disease, investigating the biological activity, toxicity, selectivity and cellular targets of different classes of compounds on T. cruzi. In this report, we present an overview of these in vitro and in vivo studies, focusing on the most promising classes of compounds with the aim of contributing to the current knowledge of the treatment of Chagas disease and aiding in the development of a new arsenal of candidates with anti-T. cruzi efficacy.

Association of hepatitis C virus NS5B variants with resistance to new antiviral drugs among untreated patients

Mutations located in the 109-amino acid fragment of NS5B are typically associated with resistance to interferon (IFN) and ribavirin (RIB) and to new antiviral drugs. The prevalence of these mutations was examined in 69 drug-naïve individuals with hepatitis C virus (HCV) infections in Rio de Janeiro, Brazil. Mutations related to non-response to IFN/RIB were observed in all subtypes studied (1a, 1b, 2b, 3a and 4). The most common mutation was Q309R, present in all subtypes, except subtype 2b with frequency above 20%. D244N was detected only in subtype 3a and A333E was detected only in subtype 2b. We did not detect the S282T, S326G or T329I mutations in any of the samples analysed. Of note, the C316N mutation, previously related to a new non-nucleoside compound (HCV796 and AG-021541), was observed in only eight of 33 (24%) samples from subtype 1b. Site 316 was under positive selection in this HCV variant. Our data highlight the presence of previously described resistance mutations in HCV genotypes from drug-naïve patients.

The nurse in the management of materials in teaching hospitals

OBJECTIVETo present the nurse's integration within materials management of six teaching hospitals of Paraná - Brazil, and to describe the activities performed by nurses within this process.METHODA study of a qualitative approach and descriptive nature, conducted in teaching hospitals in Paraná, between June and August of 2013. The data collection was conducted through semi-structured interviews with eight nurses who worked in materials management; data were analyzed using content analysis.RESULTSThese showed that nurses perform ten categories of activities, distributed into four of the five steps of the materials management process.CONCLUSIONThe nurse, in performing of these activities, in addition to favoring the development of participative management, contributes to the organization, planning, and the standardization of the hospital supply process, giving greater credibility to the work with professionals who use the materials, and to the suppliers.

Managerial nursing competencies in the expansion of the Family Health Strategy

Abstract OBJECTIVE To relate the managerial competencies required of nurses with the process of change experienced in the expansion of the Family Health Strategy (FHS). METHOD A qualitative research conducted in primary health care in a southern Brazilian city, through interviews with 32 managerial and clinical nurses. The interviews were processed by IRAMUTEQ software. The resulting classes were examined under five managerial competencies to promote change. RESULTS The four classes obtained from data were: the Family Health Strategy expansion process; confrontations and potentialities; mobilization for the change; innovations in medical and nursing consultations. The classes were related to one or more competencies. CONCLUSION The expansion of the Family Health Strategy requires managerial competencies of implementing and sustaining change, negotiating agreements and commitments, using power and influence ethically and effectively, sponsoring and selling new ideas, and encouraging and promoting innovation.

Nest distribution and nesting habits of Xylocopa ordinaria Smith (Hymenoptera, Apidae) in a restinga area in the northern Rio de Janeiro State, Brazil

This paper aims to study the distribution of natural nests of Xylocopa ordinaria and characterize its nesting habits in the restinga of Grussai/Iquipari (RJ), supporting future studies on the pollinators management in the northern Rio de Janeiro state. The data obtained from Aug/2003 to Dec/2004, in an area of 11.6ha, were related to the nest distribution, substrate identification and dimensions, emergence, sex ratio, nest structure (n= 23 nests) and pollen content analysis of provisioning masses and feces. X. ordinaria nests were abundant and presented a clustered distribution. These bees do not present taxonomical affinity for nesting substrates, but preferences for wood availability and characteristics, being Pera glabrata the main substrate. X. ordinaria is a multivoltine species that tolerates co-specifics in their nests. These bees were generalist on their nectar and pollen consumption, but presented floral constancy while provisioning brood cells. These behaviors, activity along the year, flights throughout the day, and legitimate visits to flowers indicate the importance of X. ordinaria on the pollination of plants in the restinga.

Retenção de nitrato num solo de carga variável, influenciada por adubação fosfatada e calagem

O presente trabalho teve como objetivo avaliar o efeito da aplicação de fósforo e de calcário sobre a capacidade de retenção de nitrato (CRN) de um solo de carga variável. Entre 1982 e 1989, um Latossolo Vermelho-Escuro argiloso de cerrado foi cultivado com milho, trigo, arroz e feijão (2, 4, 5 e 6 cultivos, respectivamente), recebendo adubação fosfatada (total de 1530 kg/ha de P2O5: 90 kg/ha por cultivo) ou adubação fosfatada+calagem (5,5 t/ha de calcário dolomítico: 2,5 e 3,0 t/ha em 1982 e 1985, respectivamente). Testes realizados em amostras coletadas em 1991 mostraram que o solo apresentava CRN negativa (exclusão do nitrato) na camada arável (0-20 cm), e positiva e crescente com a profundidade, nas camadas subjacentes. Os tratamentos diminuíram a CRN original do solo na camada de 20-60 cm, sendo esse efeito mais intenso no tratamento com calagem. A adubação fosfatada e, especialmente, a calagem, exerceram considerável efeito residual sobre a capacidade de retenção de nitrato do latossolo estudado.

Physiological responses of two tropical weeds to shade: I. Growth and biomass allocation

Ipomoea asarifolia (Desr.) Roem. & Schultz (Convolvulaceae) and Stachytarpheta cayennensis (Rich) Vahl. (Verbenaceae), two weeds found in pastures and crop areas in Brazilian Amazonia, were grown in controlled environment cabinets under high (800-1000 µmol m-² s-¹) and low (200-350 µmol m-² s-¹) light regimes during a 40-day period. For both species leaf dry mass and leaf area per total plant dry mass, and leaf area per leaf dry mass were higher for low-light plants, whereas root mass per total plant dry mass was higher for high-light plants. High-light S. cayennensis allocated significantly more biomass to reproductive tissue than low-light plants, suggesting a probably lower ability of this species to maintain itself under shaded conditions. Relative growth rate (RGR) in I. asarifolia was initially higher for high-light grown plants and after 20 days started decreasing, becoming similar to low-light plants at the last two harvests (at 30 and 40 days). In S. cayennensis, RGR was also higher for high-light plants; however, this trend was not significant at the first and last harvest dates (10 and 40 days). These results are discussed in relation to their ecological and weed management implications.

Physiological responses of two tropical weeds to shade: II. Leaf gas exchange and nitrogen content

Ipomoea asarifolia (Desr.) Roem. & Schultz (Convolvulaceae) and Stachytarpheta cayennensis (Rich) Vahl. (Verbenaceae), two weeds found in pastures and crop areas in the Brazilian Amazonia, Brazil, were grown in controlled environment cabinets under high (800-1000 µmol m-² s-¹) and low (200-350 µmol m-² s-¹) light regimes during a 40-day period. The objective was to determine the effect of shade on photosynthetic features and leaf nitrogen content of I. asarifolia and S. cayennensis. High-irradiance grown I. asarifolia leaves had significantly higher dark respiration and light saturated rates of photosynthesis than low-irradiance leaves. No significant differences for these traits, between treatments, were observed in S. cayennensis. Low-irradiance leaves of both species displayed higher CO2 assimilation rates under low irradiance. High-irradiance grown leaves of both species had less nitrogen per unit of weight. Low-irradiance S. cayennensis had more nitrogen per unit of leaf area than high-irradiance plants; however, I. asarifolia showed no consistent pattern for this variable through time. For S. cayennensis, leaf nitrogen content and CO2 assimilation were inversely correlated to the amount of biomass allocated to developing reproductive structures. These results are discussed in relation to their ecological and weed management implications.

Controle da fusariose em plantas de pimenta-do-reino com bactérias endofíticas: sobrevivência e respostas morfofisiológicas

Oito bactérias endofíticas de plântulas de pimenta-do-reino foram testadas em casa de vegetação, objetivando controlar Fusarium solani f. sp. piperis e avaliar respostas morfofisiológicas das plantas tratadas com os agentes de controle. Plantas com quatro meses de idade tiveram o sistema radicular tratado com as suspensões bacterianas (10(9) ufc mL-1) por 10 minutos, e foram plantadas em vasos com solo natural infestado artificialmente com o patógeno (0,25%). O delineamento experimental foi inteiramente casualizado, com três repetições para avaliar o comportamento fotossintético, a produção e a alocação de biomassa, e cinco repetições para avaliar a mortalidade das plantas. As avaliações foram feitas 120 dias após a instalação do ensaio. O isolado B0 (Methylobacterium radiotolerans) controlou F. solani f. sp. piperis, provocando redução significativa do número de plantas mortas. Na ausência do patógeno, M. radiotolerans funcionou ainda como promotor de crescimento. Os demais isolados testados não apresentaram efeito na diminuição da mortalidade das plantas. A aplicação das bactérias endofíticas não afetou a taxa fotossintética instantânea das plantas, à exceção de B6, que teve efeito negativo. As plantas tratadas com M. radiotolerans priorizaram a alocação de carbono para a parte aérea.

Physiological and morphological responces of Brachiaria spp. to flooding

The physiological and morphological responses of the forage grasses Brachiaria brizantha cv. Marandu, B. decumbens and B. humidicola were compared for plants grown in pots under flooding and well-drained conditions for 14 days. Flooding reduced specific leaf area and biomass allocation to roots in all species and enhanced leaf senescence in B. brizantha and B. decumbens. Relative growth rate was reduced by flooding in B. brizantha and B. decumbens, but not in B. humidicola.Leaf elongation rate was unaffected by flooding in B. decumbens and B. humidicola, but declined in B. brizantha since the first day of flooding. Net photosynthesis and leaf chlorophyll content were reduced by flooding in B. brizantha; however, no flooding effect could be detected in the other two species. For all species, there was a close relationship between net photosynthesis and stomatal conductance under flooding. These results show that the studied species have distinct degrees of tolerance to flood, B. brizantha is intolerant, B. decumbens is moderately tolerant and B. humidicola is tolerant. Because leaf elongation rate was immediately depressed by flooding only in B. brizantha, this measurement could be appropriate as an early detection mechanism for relative flood tolerance in Brachiaria spp.

Growth and biomass allocation of the C4 grasses Brachiaria brizantha and B. humidicola under shade

The growth and biomass allocation responses of the tropical forage grasses Brachiaria brizantha cv. Marandu and B. humidicola were compared for plants grown outdoors, in pots, in full sunlight and those shaded to 30% of full sunlight over a 30day period. The objective was to evaluate the acclimation capacity of these species to low light. Both species were able to quickly develop phenotypic adjustments in response to low light. Specific leaf area and leaf area ratio were higher for low-light plants during the entire experimental period. Low-light plants allocated significantly less biomass to root and more to leaf tissue than high-light plants. However, the biomass allocation pattern to culms was different for the two species under low light: it increased in B. brizantha, but decreased in B. humidicola, probably as a reflection of the growth habits of these species. Relative growth rate and tillering were higher in high-light plants. Leaf elongation rate was significantly increased on both species under low light; however, the difference between treatments was higher in B. brizantha. These results are discussed in relation to the pasture management implications.

Tolerance to flooding in five Brachiaria brizantha accessions

Some physiological and morphological responses of five Brachiaria brizantha accessions (BRA000591 cultivar Marandu, BRA003441, BRA002844, BRA004308 and BRA004391) were compared for plants grown in pots under flooding and well-drained conditions for 14 days. Flooding caused a significant reduction in leaf dry mass production in all accessions, but, for root biomass, no differences between treatments could be detected in BRA003441 and BRA004391. No adventitious root production was observed in flooded BRA003441; all other accessions produced adventitious roots when flooded. Relative growth rate was reduced by flooding only in BRA000591 and BRA004308. Leaf elongation rate was reduced by flooding in all accessions, however, more severely in BRA003441. Net photosynthesis was reduced by flooding in all accessions, but with less intensity in BRA004391. For all accessions, there was a close relationship between net photosynthesis and stomatal conductance under flooding. The five accessions tested differed in tolerance to flooding. BRA004391 was the most tolerant. Accession BRA003441 was the most sensitive, followed by BRA000591 cultivar Marandu. Accessions BRA002844 and BRA004308 were classified as intermediate in flooding tolerance.

Characterization of rue extract and its potential for controlling rice blast

Abstract: The objective of this work was to purify and standardize the rue (Ruta graveolens) extract and evaluate its effect on Magnaporthe oryzae as an alternative to the integrated management of rice blast. The drug was characterized, the liquid extract was obtained, and the methodology for quantifying the standard markers psoralen and bergapten was validated. Rue extract and the markers, solely or in combination, were assayed in vitro, as well as in greenhouse conditions, for their ability to suppress leaf blast, by the evaluation of mycelial growth, conidial germination, and appressorium formation. Rue extract inhibited M. oryzae mycelial growth (100%), conidial germination (LD50=0.237 mg), and the appressorium formation (LD50=0.121 mg); besides, the extract reduced leaf blast severity by 80.84%. Fluorescence microscopy showed that rue extract did not damage M. oryzae cell wall and plasma membrane, indicating another mode of action. Rue extract has a great potential for controlling rice leaf blast.