Natural and anthropogenic factors associated with the distribution of South American sea lion along the Atlantic coast

The aim of this work was to analyse those characteristics of the Atlantic coast that are associated with distribution, abundance and breeding activity of Otaria flavescens at three ecological scales. We followed a research strategy that consists in looking at the variables that are associated with the pattern of distribution at regional and landscape scales, instead of following local population in time. We used bibliographic data of censuses carried out between 1946 and 1997 and a Geographic Information System (GIS) to integrate information proceeding from censuses and different environmental variables. At a regional scale, we found that the distribution of breeding colonies did not vary in the period of time analysed and was associated with the pattern of occupation of the coast and the tide width. There was a significant decrease in abundance between 1946 and 1997. In ‘north-central Patagonia’, the segment of coast with the highest number of sea lions in Argentina, distribution of colonies was associated with islands availability and negatively correlated with places were anthropogenic disturbance was high. At a local scale, breeding colonies were positive associated with slight slope coasts and negatively associated to rocky beaches. We identify those characteristics of the coast associated with distribution of breeding colonies of O. flavescens, which operate at different ecological and temporal scales. Handling editor: K. Martens     

Asymmetric Spatiotemporal Evolution of Prebiotic Homochirality

The role of asymmetry on the evolution of prebiotic homochirality is investigated in the context of autocatalytic polymerization reaction networks. A model featuring enantiometric cross-inhibition and chiral bias is used to study the diffusion equations controlling the spatiotemporal development of left and right-handed domains. Bounds on the chiral bias are obtained based on present-day constraints on the emergence of life on early Earth. The viability of biasing mechanisms such as weak neutral currents and circularly polarized UV light is discussed. The results can be applied to any hypothetical planetary platform.     

Caatinga Ethnobotany: Anthropogenic Landscape Modification and Useful Species in Brazil’s Semi-Arid Northeast

Caatinga Ethnobotany: Anthropogenic Landscape Modification and Useful Species in Brazil’s Semi-Arid Northeast This study explores the contribution of anthropogenic landscapes in providing useful botanical resources to a Caatinga community in Pernambuco, Brazil. Ethnobotanical data were collected through semi-structured interviews using the checklist-interview method and by means of a “field herbarium” of the most abundant species in the anthropogenic zones. We recorded 119 species distributed in 36 families, of which 79 were found to be useful. Forage was the most prominent use category, containing 84% of the citations, followed by medicinals (36.70%), foods (10.12%), and wood (8.86%). Herbaceous species predominated (63.29%), followed by shrubs (3.79%), sub-shrubs (21.51%), trees (8.86%), and creepers (2.53%). Trees exhibited a greater number of uses than other life-forms (p < 0.05). Significant differences in richness were found, with the highest richness of species (χ2 = 60.28, p < 0.05), genera (χ2 = 49.03, p < 0.05), and families (χ2 = 20.16, p < 0.05) appearing in the rainy season. We concluded that fodder use was the most important category in our anthropogenic research areas, accounting for a higher number of species, genera, and families. The next most important categories were medicinal, timber, and food plants, respectively.     

Purification,characterization, sequence determination,and mass spectrometric analysis of a trypsin inhibitor from seeds of the brazilian treeDipteryx alata (leguminosae)

Dipteryx alata trypsin inhibitor (DATI) has been purified and completely sequenced. It showed homology to members of the Bowman-Birk family of inhibitors. The last step of DATI purification by RP-HPLC (narrow-bore C18 column) suggested the existence of some isoforms of the inhibitor due to the presence of a cluster of very close peaks in the chromatogram. By using electrospray ionization mass spectrometry (ESIMS) and laser desorption mass spectrometry (LDIMS), the identification of DATI isoforms was made possible. From the ESIMS data, the following molecular masses were found: 6803.22±0.92 for isoforma; 6890.94±0.73 forb; 6977.58±0.39 for c; 7065.07±0.67 ford; 7151.42±0.86 for e; and 7291.70±0.43 forf. Similar masses were found when using LDIMS. Isoformb was the most abundant and its molecular mass matched the molecular mass of 6893 calculated from the sequence of DATI. The mass differences betweena andb, b andc, c andd, andd ande were equal to 87, which corresponds to Ser. Isoforma might not have the N-terminal Ser present in isoformb, while the other additional Ser residues might comprise a row localized in the C- or N-terminal. The appearance of all these isoforms could result from posttranslational N- and C-terminal processing.     

Taking Aim

Taking Aim. 1993. 41 min., color. video by Monica Frota. For more information contact Monica Frota at Rua Visconde de Ouro Preto 611/201, Rio de Janeiro, Brazil 22250-180, (55 21 5376235).     

Non-fluoroscopic catheter ablation: A randomized trial

BackgroundCatheter ablation provides curative treatment for tachyarrhythmias. Fluoroscopy, the method used for this, presents several risks. The electroanatomical mapping (MEA) presents a three-dimensional image without using X-rays, and may be adjunct to fluoroscopy.ObjectivesWe evaluated the possibility of performing catheter ablation with the exclusive use of electroanatomical mapping (MEA), dispensing with fluoroscopy. We compared the total time of procedure and success rates against the technique using fluoroscopy (RX) with emission of X-rays.MethodsRandomized, unicentric, uni-blind study of patients referred for tachyarrhythmia ablation.ResultsTwelve patients were randomized to the XR group and 11 to the EAM group. The mean age was 48.5 (±12.6) vs 46.3 (±16.6) (P = ns). Success occurred in 11 patients (91.7%) in the RX group and 9 (81.8%) in the MEA group (P = 0.46). The procedure time in minutes was higher in the MEA group than in the RX group (79-47-125min vs 49-30-100min; P = 0.006). The mean fluoroscopy time was 11 ± 9 min versus zero (RX vs MEA: P < 0.001). The mean radiofrequency applications were lower in the RX group against the MEA group (6 ± 3.5 × 13.2 ± 18.2 p < 0.019). There were no complications.ConclusionMEA opened new therapeutic possibilities for patients with arrhythmias, reducing the risk of radiation. In this study, it was possible to demonstrate that it is feasible to perform ablation only with the use of MEA, with similar success with fluoroscopy, at the expense of a longer procedure time.     

Response of two parasitoid species (Hymenoptera: Braconidae,Figitidae) to tephritid host and host food substrate cues

The Neotropical‐native figitid Aganaspis pelleranoi (Brèthes) and the Asian braconid Diachasmimorpha longicaudata (Ashmead) are two parasitoids of Tephritidae fruit flies with long and recent, respectively, evolutionary histories in the Neotropics. Both species experienced a recent range of overlap. In Argentina, A. pelleranoi is a potential species in biological control programs against the pestiferous tephritid species, Anastrepha fraterculus (Wiedemann) and Ceratitis capitata (Wiedemann), whereas D. longicaudata is already used in open‐field releases against Medfly in central‐western Argentina. To characterize the host‐foraging strategies of A. pelleranoi and D. longicaudata, olfactometer experiments were conducted comparing responses to C. capitata and A. fraterculus larvae, in two kinds of food substrate: fruit and artificial larval medium. To control the possible influence of host larvae used for parasitoid rearing on olfactory response, two strains of both parasitoid species, reared on both tephrtid species, were studied. Volatiles directly emanating either from A. fraterculus or C. capitata larvae may be detected by both A. pelleranoi and D. longicaudata, although chemical stimuli originating from the combination of host larvae and the habitat of the host were preferred. However, olfactory cues associated with host larvae probably play a relevant role in host searching behaviour of A. pelleranoi, whereas for D. longicaudata, the host‐habitat olfactory stimuli would be highly essential in short‐range host location. The strain of the parasitoids did not affect host search ability on the two tephritid species evaluated. These evidences are relevant for mass production of both parasitoids and their impact following open‐field augmentative releases.