Chemical treatment of papaya seeds aiming at long-term storage and control of damping off

Damping off is a nursery disease of great economic importance in papaya and seed treatment may be an effective measure to control. The aim of this work was to evaluate the quality of papaya seeds treated with fungicides and stored under two environmental and packaging conditions. Additionally, the efficiency of fungicide treatments in the control of damping-off caused by Rhizoctonia solani was evaluated. Papaya seeds were treated with the fungicides Captan, Tolylfluanid and the mixture Tolylfluanid + Captan (all commercial wettable powder formulations). Seeds of the control group were not treated. The seeds were stored for nine months in two conditions: packed in aluminum coated paper and kept at 7 ± 1ºC and in permeable kraft paper and kept in non-controlled environment. At the beginning of the storage and every three months the seed quality (germination and vigor tests), emergence rate index, height, dry mass and damping of plants in pre and post-emergence (in contaminated substrate and mycelia-free substrate) were analyzed. Both storage conditions as well as the fungicide treatments preserved the germination and seed vigor. In the infested substrate, seedling emergence was favored by fungicides, but in post-emergence, fungicides alone did not control the damping off caused by R. solani. Symptoms of damping off were not observed in the clean substrate. The results showed that the fungicide treatments may be used to pretreat papaya seed for long-term storage and commercialization.

Antifungal susceptibility and distribution of Candida spp. isolates from the University Hospital in the municipality of Dourados, State of Mato Grosso do Sul, Brazil

Introduction Hospital infections caused by Candida spp. are a leading cause of morbidity and mortality in hospitalized patients, particularly those that are critically ill or immunocompromised. In this study, the distribution of Candida species in isolates from the University Hospital of the Federal University at Grande Dourados and their in vitro susceptibility to antifungal drugs were analyzed. Methods Yeasts were phenotypically identified using classical methodologies. Antifungal susceptibility tests to amphotericin B and fluconazole were performed using the broth microdilution technique. Results A total of 50 Candida isolates were obtained from hospitalized patients during the study period. We analyzed yeast isolates from urine (n=31; 62%), blood (n=12; 24%), and tracheal secretions (n=7; 14%). The following Candida species were identified: C. tropicalis (n=21; 42%), C. albicans (n=18; 36%), C. glabrata (n=10; 20%), and C. krusei (n=1; 2%). Antifungal susceptibility tests demonstrated that C. albicans was susceptible to both antifungal agents. However, 31.2% of the non-C. albicans Candida isolates displayed dose-dependent susceptibility to fluconazole, and 3.1% were resistant to amphotericin B. Conclusions In contrast to previous reports, our results indicated that C. tropicalis was the most commonly isolated yeast species among the hospital patients. The predominance of non-C. albicans Candida infections confirms the importance of species-level identification for implementing appropriate antifungal therapies.

Density, size and distribution of stomata in 35 rainforest tree species in Central Amazonia

Stomata are turgor-operated valves that control water loss and CO2 uptake during photosynthesis, and thereby water relation and plant biomass accumulation is closely related to stomatal functioning. The aims of this work were to document how stomata are distributed on the leaf surface and to determine if there is any significant variation in stomatal characteristics among Amazonian tree species, and finally to study the relationship between stomatal density (S D) and tree height. Thirty five trees (>17 m tall) of different species were selected. Stomatal type, density (S D), size (S S) and stomatal distribution on the leaf surface were determined using nail polish imprints taken from both leaf surfaces. Irrespective of tree species, stomata were located only on the abaxial surface (hypostomaty), with large variation in both S D and S S among species. S D ranged from 110 mm-2 in Neea altissima to 846 mm-2 in Qualea acuminata. However, in most species S D ranges between 271 and 543 mm-2, with a negative relationship between S D and S S. We also found a positive relationship between S D and tree height (r² = 0.14, p < 0.01), but no correlation was found between S D and leaf thickness. The most common stomatal type was anomocytic (37%), followed by paracytic (26%) and anisocytic (11%). We conclude that in Amazonian tree species, stomatal distribution on the leaf surface is a response most likely dependent on the genetic background of every species, rather than a reaction to environmental changes, and that somehow S D is influenced by environmental factors dependent on tree height.

Structure and distribution of glandular trichomes in three species of Bignoniaceae

Glandular trichomes play a major role in the morphological characterization of the Bignoniaceae. Due to their great diversity of forms and functions, this study aimed to inventory the glandular trichomes present in the aerial vegetative axis of Amphilophium magnoliifolium, Martinella obovata and Stizophyllum riparium, analyze their structure and register the participation of ants in these plants. Fresh samples from the nodal region, petiole and from medium to apical regions of the leaflet blade were fixed and processed according to usual methods in light and scanning electron microscopies. The glandular trichomes found were: peltate, capitate, stipitate, and patelliform/cupular. Peltate trichomes are the most abundant ones and present the most uniform distribution. Patelliform/cupular trichomes occur at specific regions, such as prophylls, leaflet blade and nodal regions. Martinella obovata is the only species that presents capitate and stipitate trichomes, which are widely distributed along the entire aerial vegetative axis. Ants were found in all species, mainly at nodal regions. The occurrence of the capitate-type trichome is reported for the first time to the genus.

Sewage impact on the composition and distribution of Polychaeta associated to intertidal mussel beds of the Mar del Plata rocky shore, Argentina

The polychaete composition and distribution within mussel beds were studied in order to assess organic pollution due to domestic sewage in a rocky shore of Mar del Plata (Argentina) during 1997. Four stations and a control site were randomly sampled around the local effluent. Quantitative data on polychaetes, as well as sediment accumulated among mussels and its organic carbon content were measured. Polychaete distribution patterns are related to the organic matter gradient, being Capitella cf. capitata, Neanthes succinea (Frey & Leuckart, 1847) and Boccardia polybranchia (Haswell, 1885) the dominant indicator species close to the effluent. At medial distances, the cirratulids Caulleriella alata (Southern, 1914) and Cirratulus cirratus (Müller, 1776) are very important in abundance. The syllids Syllis prolixa Ehlers, 1901 and S. gracilis Grube, 1840 are distributed along the study area, but dominate at the medial stations and at the control site. The orbiniid Protoariciella uncinata Hartmann-Schröder, 1962 is subdominant at the control station.

Biosyslematics and distribution of Simuliid vectors of human onchocerciasis in South America

A brief review is given of the taxonomic status, biology and medical importance, and distribution of the vectors of human onchocerciasis in Latin America. Key reference works are cited and distribution maps of each vector species in relation to the known onchocerciasis foci are given.

Taxonomy and distribution of phlebotomine sandflies in Venezuela: I. The Oswaldoi species group of the genus Lutzomyia (Diptera: Psychodidae)

Species of sandflies in the oswaldoi-group of the genus Lutzomyia occuring in Venezuela are reviewed. A new species, Lutzomyia saccai n. sp. is described. A distribution map and pictorial keys for males and females are provided with notes on biological and ecological data collected in Venezuela.

Taxonomy and distribution of phlebotomine sandflies in Venezuela: II. The subgenus Trichopygomyia of the genus Lutzomyia (Diptera: Psychodidae)

Species of sandflies in the subgenuys Trichopygomyia of the genus Lutzomyia occurring in Venezuela are reviewd. A new species, Lutzomyia pinna n. sp. is described. A distribution map and a pictorial key for maleds are provided with remarks on the ecological data collected in Venezuela.

Eokines: synthesis, storage and release from human eosinophils

Eosinophils are prominent inflammatory cells in asthma and other allergic disorders, as well as in helminthic parasite infections. Recently, eosinophils have been reported to synthesize and store a range of regulatory proteins within their secretory granules (eokines). Eokines comprise a group of cytokines, chemokines, and growth factors which are elaborated by eosinophils. These proteins, and the messages which encode them, appear to be identical to those produced by lymphocytes and other tissues. Interestingly, immunoreactivity to many of these eokines has been found to co-localize to the eosinophil´s secretory granules. In this review, we have discussed the repertoire of 18 eokines so far identified in eosinophils, and focused on four of these, namely, interleukin-2 (IL-2), IL-4, granulocyte/macrophage colony-stimulating factor (GM-CSF), and RANTES. These four eokines co-localize to the crystalloid granules in eosinophils, as shown in studies using subcellular fractionation and immunogold labeling in electron microscopy. During stimulation by physiological triggers, for example, with serum-coated particles, eosinophils release these mediators into the surrounding supernatant. In addition, eokines are likely to be synthesized within eosinophils rather than taken up by endocytosis, as show in detection of mRNA for each of these proteins using in situ hybridization, RT-PCR, and in the case of RANTES, in situ RT-PCR. Eokines synthesis and release from eosinophils challenges the commonly held notion that these cells act downstream of key elements in immune system, and indicate that they may instead belong to the afferent arm of immunity.

Long-term storage and viability of Ochlerotatus albifasciatus (Diptera: Culicidae)

The viability of Ochlerotatus albifasciatus (Macquart) eggs stored at room temperature and at 5ºC was studied over 31 months. After 12, 18 and 31 months of storage, eggs were acclimatized at 22ºC for ten days, and then inundated twice every seven days. The effect of the storage period on the percentage of hatching was analyzed by one way ANOVA. Differences on the hatching response between the first and second flooding were analyzed by paired t-test. Differences on the hatching response between the two storage conditions were analyzed by Mann-Whitney rank test. Results showed that (1) Oc. albifasciatus eggs were able to survive and hatch over 31 months; (2) the percent hatching of eggs stored at 5ºC was higher than that of eggs stored at room temperature; and (3) low temperatures and long periods without water favor installment hatching.

Mansonella ozzardi in Amazonas, Brazil: prevalence and distribution in the municipality of Coari, in the middle Solimões River

This study investigated some epidemiological aspects of the Mansonella ozzardi in municipality of Coari, Amazonas. Clinical symptoms were correlated with the filarial infection and the parasitic infection rates (PIR) were estimated in simuliid vectors. The general M. ozzardi human prevalence rate was 13.3% (231/1733), of which 10.2% (109/1069) were from the urban area and 18.4% (122/664) from the rural area. The prevalence rates were higher in men (14.5% urban and 19.7% rural) than in women (6.7% urban and 17.2% rural) and occurred in most age groups. The indices of microfilaremics were higher in people > 51 years old (26.9% urban and 61.5% rural). High prevalence rates were observed in retired people (27.1% urban area), housewives and farmer (41.6% and 25%, respectively, in rural area). The main clinical symptoms were joint pains and sensation of leg coldness. Only Cerqueirellum argentiscutum (Simuliidae) transmits M. ozzardi in this municipality (PIR = 5.6% urban and 7.1% rural). M. ozzardi is a widely distributed parasitic disease in Coari. Thus, temporary residency in the region of people from other localities involved with the local gas exploitation might be a contributing factor in spreading the disease.

Diversity and distribution of sandflies (Diptera: Psychodidae: Phlebotominae) in a military area in the state of Amazonas, Brazil

This study reports the distribution, ecotopes and fauna diversity of sandflies captured in five training bases on a military reserve in Manaus, state of Amazonas (AM). A total of 10,762 specimens were collected, which were distributed among 58 species, with the highest number recorded at Base Instruction 1 (BI1). A higher rate of species richness was found at the Base Instruction Boina Rajada and low levels of diversity associated with a high abundance index with the clear dominance of Lutzomyia umbratilis, Lutzomyia ruii and Lutzomyia anduzei were found at BI1. The abundance of Lu. umbratilis raises the possibility of outbreaks of American cutaneous leishmaniasis by the main vector of the disease in AM.

Density and distribution of nests of Mycetophylax simplex (Emery) (Hymenoptera, Formicidae) in areas with mobile dunes on the northern coast of Rio Grande do Sul, Brazil

Studies on lower attines are scarce, especially on nesting and foraging ecology and behavior. This study aimed to contribute to the knowledge of an Attini in dunes ecosystems through the description of density and spatial distribution of Mycetophylax simplex (Emery, 1887) nests in a strip of mobile dunes in the Praia Grande beach, Torres, northern coast of Rio Grande do Sul, Brazil. The density and spatial distribution of nests were estimated in four plots of 2,500 m² each, in which were found 20, 209, 284 and 324 nests, with average densities of 0.01 nests/m², 0.09, 0.11 and 0.13 nests/m², respectively. The nests were found near to the vegetation and showed clumped distribution. The density and distribution pattern of the nests seem to be related to the availability of nesting places and foraging resources.

Systematics and distribution of the genus Johnsonius Marsh (Hymenoptera, Braconidae, Doryctinae) with description of two new species from Brazil

The genus Johnsonius Marsh includes five species, most of them known from Costa Rica and one known from Venezuela, Peru and Costa Rica. Two of these species and two new species were recently collected in Atlantic rain forest. Description of the new species, illustrations of some morphological characters, a key for identification of all known species and the new geographic records are presented.