Feeding behavior of the Yellow-chevroned Parakeet at the northeast of the State of Sao Paulo State, Brazil

This research was carried out from March 1990 to December 1993. It was designed to obtain data on the feeding behavior of the Yellow-chevroned Parakeet (Brotogeris chiriri) at four distinct areas of northeast Sao Paulo State. The following aspects of its feeding biology have been addressed: the plant species used as food, the items (flower, fruit, pulp, seed) included in the diet, the methods used to obtain food, and the flock size variation. Brotogeris chiriri used 45 plant species as food resource. From these it used seeds from 27 species, fruit pulp from 19 species and flowers from 16 species. There was a significant statistical variation on the methods used to gather food relative to the food item. The flock size of B. chiriri is highly variable (from one individual eating alone to about 45 individuals) on the same period of the year. The smallest average flock size was found during the breeding period of the species.1519510

Metabolic and morphological alterations induced by proteolysis-inducing factor from Walker tumour-bearing rats in C2C12 myotubes

BACKGROUND: Patients with advanced cancer suffer from cachexia, which is characterised by a marked weight loss, and is invariably associated with the presence of tumoral and humoral factors which are mainly responsible for the depletion of fat stores and muscular tissue. METHODS: In this work, we used cytotoxicity and enzymatic assays and morphological analysis to examine the effects of a proteolysis-inducing factor (PIF)-like molecule purified from ascitic fluid of Walker tumour-bearing rats (WF), which has been suggested to be responsible for muscle atrophy, on cultured C2C12 muscle cells. RESULTS: WF decreased the viability of C2C12 myotubes, especially at concentrations of 20-25 mug.mL-1. There was an increase in the content of the pro-oxidant malondialdehyde, and a decrease in antioxidant enzyme activity. Myotubes protein synthesis decreased and protein degradation increased together with an enhanced in the chymotrypsin-like enzyme activity, a measure of functional proteasome activity, after treatment with WF. Morphological alterations such as cell retraction and the presence of numerous cells in suspension were observed, particularly at high WF concentrations. CONCLUSION: These results indicate that WF has similar effects to those of proteolysis-inducing factor, but is less potent than the latter. Further studies are required to determine the precise role of WF in this experimental model. © 2008 Yano et al; licensee BioMed Central Ltd

Coinfection with Different Trypanosoma cruzi Strains Interferes with the Host Immune Response to Infection

A century after the discovery of Trypanosoma cruzi in a child living in Lassance, Minas Gerais, Brazil in 1909, many uncertainties remain with respect to factors determining the pathogenesis of Chagas disease (CD). Herein, we simultaneously investigate the contribution of both host and parasite factors during acute phase of infection in BALB/c mice infected with the JG and/or CL Brener T. cruzi strains. JG single infected mice presented reduced parasitemia and heart parasitism, no mortality, levels of pro-inflammatory mediators (TNF-α, CCL2, IL-6 and IFN-γ) similar to those found among naïve animals and no clinical manifestations of disease. On the other hand, CL Brener single infected mice presented higher parasitemia and heart parasitism, as well as an increased systemic release of pro-inflammatory mediators and higher mortality probably due to a toxic shock-like systemic inflammatory response. Interestingly, coinfection with JG and CL Brener strains resulted in intermediate parasitemia, heart parasitism and mortality. This was accompanied by an increase in the systemic release of IL-10 with a parallel increase in the number of MAC-3+ and CD4+ T spleen cells expressing IL-10. Therefore, the endogenous production of IL-10 elicited by coinfection seems to be crucial to counterregulate the potentially lethal effects triggered by systemic release of pro-inflammatory mediators induced by CL Brener single infection. In conclusion, our results suggest that the composition of the infecting parasite population plays a role in the host response to T. cruzi in determining the severity of the disease in experimentally infected BALB/c mice. The combination of JG and CL Brener was able to trigger both protective inflammatory immunity and regulatory immune mechanisms that attenuate damage caused by inflammation and disease severity in BALB/c mice

DIET AND FEEDING BEHAVIOR OF THE YELLOW-FACED PARROT (ALIPIOPSITTA XANTHOPS) IN BRASILIA, BRAZIL

There are only few reports on the biology of the near threatened Yellow-faced Parrot Alipiopsitta xanthops, and this is the first systematic study on the species diet over a year. The study was carried out in 2006 in Brasilia, Brazil. Observations consisted of feeding-bouts on plant species consumed by parrots and the attainment behavior. The species seems to be a foraging generalist, feeding on fruits, seeds, and leaves of 15 different plant species. We also registered ingestion of uncommon items such as soil and bark. We observed and described two main attainment methods: direct and indirect access. Preference for food attainment method varied according to plant morphology but parrots were also observed using both methods on the same plant species. Parrots used their feet when food resources were aggregated, allowing access to several food items. That way they improved feeding efficiency through searching time reduction. The parrots switch attainment method depending on the plant phenological stage. When fruits are closed and access is only possible through handling, parrots use indirect access. When fruits are open, parrots use direct access, reducing handling time. The left foot was mostly used during indirect access, but we also observed ambidextrous individuals. A total of 35 plant species has been so far recorded as part of the diet of the Yellow-faced Parrots, with a great turnover on species composition as it should be expected for a foraging generalist. Accepted 4 February 2011.2217988Faepex (Unicamp)Katherine Mclennan Brown Charitable Foundatio

Vocal Repertoire of the Yellow-Faced Parrot (Alipiopsitta xanthops)

We describe the vocal repertoire of the Yellow-faced Parrot (Alipiopsitta xanthops) from recorded vocalizations and also flock sizes in Brasilia (Brazil) during 2006. Vocal communication signals are both long-range and short-range sounds. We describe seven call types: flight call (long-range), long-range alarm call, congregation call (long-range), two agonistic calls (long-range/short-range), sentinel call (shortrange), and a short-range alarm call. The flight call is equivalent to the functional song and contains the species-specific recognition code. Flight calls may also be uttered when perched and, when in quick series, function as long-range alarm calls. Long-range alarm calls become a high intensity congregation signal when several individuals overlap and, despite degradation and attenuation, may contain the species-specific code over distances of 800 m. The average (+/- SD) feeding flock size was 7.7 +/- 8.2 individuals (n = 116) while the roosting flock size was 79.1 +/- 10.5 individuals (n = 7). Short-range calls maintain communication while minimizing detection. High intensity vocalizations allow long-range communication, improving feeding efficiency through use of large areas and stimulating late afternoon roost congregations. Low intensity vocalizations maintain communications without providing the position of the parrot. Received 22 June 2010. Accepted 9 February 2011.1233603608Faepex (Unicamp)Katherine McLennan Brown Charitable Foundatio

The importance of biotic interactions in species distribution models: a test of the Eltonian noise hypothesis using parrots

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)AimTo test the Eltonian noise hypothesis (ENH), that biotic interactions do not affect species distributions at large geographical scales. LocationThe Brazilian cerrado, a central South American savanna and biodiversity hotspot. MethodsWe modelled the distributions of 11 species of cerrado parrots using the software Maxent at four different spatial resolutions. We built models using abiotic variables, biotic variables (distribution of diet resources) and models combining abiotic and biotic variables. We compared model performance using the area under the curve of the receiver operating characteristic (AUC), retrieved from test data. We partitioned the variance between sets of predictors using a generalized linear model (GLM). Finally, we evaluated whether improvement in model performance (higher AUC values) in models with both abiotic and biotic variables, was related to the species' dietary niche breadth and/or spatial resolution of the models. ResultsWe found that model performance was improved in most cases by the addition of biotic variables. Our variance-partitioning approach revealed that abiotic and biotic variables contribute independently to the final model. We found no relationship between model improvement and spatial resolution. We also found no relationship between dietary niche breadth and model improvement, indicating that dietary generalist and specialist species were not differently affected by the inclusion of biotic variables in the models. Main conclusionsOur results did not support the ENH. In this study, we explicitly incorporated a biotic variable (diet resource distribution) into species distribution models (SDMs), and we showed that these variables generally improve models and have independent contributions. These results agree with previous studies that incorporated biotic variables into SDMs. Ultimately, our results indicate that SDMs performed with abiotic variables only may depict only a partial representation of the geographical distribution of a species.413513523Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)CNPq [563352/2010-8, 140121/2009-9