How do frequent fires in the Cerrado alter the lepidopteran community?

Despite the great biodiversity of lepidopterans, there are few studies focusing on caterpillars and the effects of fire on their community structure in the Cerrado. The aim of this study was to evaluate the effects of frequent fires every 2 years for 16 years, on the Lepidoptera larval community hosted on Byrsonima coccolobifolia (Malpighiaceae). The study was carried out in the Cerrado sensu stricto in the Reserva Ecológica of the Instituto Brasileiro de Geografia e Estatística (IBGE-RECOR) (15°55′–15°58′S, 47°52′–47°55′W), in Distrito Federal, Brazil, from December 2005 to August 2006. We selected two burned parcels, one of which was burned during the mid-dry season (FM) and the other of which burned in the late dry season (FL), in addition to a preserved, unburned parcel (FA). In each parcel, 900 plants of B. coccolobifolia were inspected for caterpillars, which were then collected and reared in a laboratory of the University of Brasilia. We found 480 caterpillars from 49 species distributed in 16 Lepidoptera families. The frequency of plants with larvae, the number of caterpillars and species composition varied among parcels. In the unburned parcel the frequency of plants with caterpillars was 2.4 and 5.2 times higher than in burned parcels (FM and FL), respectively. The species richness did not differ among parcels, and an asymptotic curve was nearly reached in only the unburned parcel. The dominant species in the preserved parcel was Cerconota achatina (Elachistidae). In the FM, the dominant species was Concana mundissima (Noctuidae) and in the FL, the dominant species was Stenoma salome (Elachistidae). The dissimilarity between unburned and burned parcels was 64%. Results indicated that fire events have a strong negative impact on caterpillar abundance and species composition.     

Tissue Nitrogen and Phosphorus in Seaweeds in a Tropical Eutrophic Environment: What a Long-Term Study Tells Us

Percentages of nitrogen and phosphorus in 10 species of seaweeds (6 green and 4 red algae) were monitored from 1997 to 2004 by seasonal sampling in Guanabara Bay, South-eastern Brazil. The species did not show consistent variations in tissue N, P and N:P that related to annual cycles. Throughout this study, higher percentages of tissue N and P were found in Bostrychia radicans and Grateloupia doryphora (red algae) and lower in Cladophora rupestris and Codium decorticatum (green algae). In November 1999, the Icaraí Submarine Sewage Outfall became operational, resulting in a reduction of visual pollution in the area and an improvement in the local quality of seawater for recreational use. Measurements of dissolved nutrients at the sampling site did not indicate significant changes in concentrations after the commissioning of the submarine sewage outfall; however, tissue P and N:P ratio of most of species were significantly lower than in the first two years of this survey. Variations in tissue nitrogen throughout this study were not significant, except for G. doryphora in some comparisons. Results show that seaweeds function very well as monitors of environmental changes in Guanabara Bay. Experimental data are needed to identify possible environmental processes which are promoting changes in chemical composition of the local seaweed populations.     

The presence of serum anti-Ascaris lumbricoides IgE antibodies and of Trichuris trichiura infection are risk factors for wheezing and/or atopy in preschool-aged Brazilian children

Background

The elucidation of factors that trigger the development of transient wheezing in early childhood may be an important step toward understanding the pathogenesis of asthma and other allergic diseases later in life. Transient wheezing has been mainly attributed to viral infections, although sensitisation to aeroallergens and food allergens may occur at an early age. In developing countries, intestinal helminthic infections have also been associated with allergy or atopy-related disorders.

Objective

The aim of this study was to explore the association of Trichuris trichiura and Ascaris lumbricoides infections with wheezing and atopy in early childhood.

Study design

A cross-sectional study using a Portuguese-language ISAAC phase I questionnaire, adapted for preschool-aged children, nested in a cohort study of childhood diarrhoea, was conducted on 682 children. Two faecal samples per child were examined for the presence of intestinal helminthic infection. IgE antibodies against three allergenic preparations (Dermatophagoides pteronyssinus, Blomia tropicalis and common child food), as well as against A. lumbricoides antigens, were measured in a sub-sample of these children, whose parents allowed the procedure. Atopy was defined by the presence of levels of serum IgE antibodies ≥0.35 kU/L against at least one of the three tested allergenic preparations.

Results

Active T. trichiura infection but not A. lumbricoides infection was positively associated with wheezing in the total studied children population [adjusted OR = 2.60; CI = 1.54;4.38] and in the atopic children sub-population [adjusted OR = 3.07; CI = 1.00;9.43]. The association with atopy was also positive and statistically significant only in the brute analysis [OR = 2.13; CI = 1.03;4.40]. Anti-A. lumbricoides IgE antibodies, but not current A. lumbricoides infection, were positively associated with wheezing in atopic children [adjusted OR = 2.01; CI = 1.00;4.50] and in non-atopic children [adjusted OR = 3.07; CI = 1.13;8.35] and it was also associated with atopy [adjusted OR = 7.29; CI = 3.90; 13.4]. On the other hands, reports of wheezing were not significantly associated with atopy.

Conclusions

These data corroborate previous studies showing that wheezing is predominantly associated with infection in early childhood and shows that anti-A. lumbricoides IgE antibodies, but not active Ascaris infections, are associated with wheezing and atopy. Additionally, the data demonstrate that T. trichiura infection may play a role in the pathogenesis of atopic wheezing in early childhood.     

Low temperature conversion of rice husks, eucalyptus sawdust and peach stones for the production of carbon-like adsorbent

In this study, the feasibility of preparing effective adsorbents from unmitigated agroforestry wastes was investigated. Three different kinds of carbon-like materials were produced by low temperature pyrolysis (LTC, <500 degrees C) of the raw materials rice husks, eucalyptus sawdust and peach stones. The carbon-like materials were characterized by instrumental methods (SEM,X-RDS,BET,MAS-RMN,FTIR), physico-chemical adsorption (iodine-, methylene blue- and phenazone-number; acetic acid adsorption isotherm; textile dyes- and carbohydrate adsorption), and heat value determination. The produced materials, which showed appreciable adsorption capacity, can be considered as precursors for the production of active coal or even be used directly as well.