Do morphological and physiological characteristics of males of the dragonfly Macrothemis imitans determine the winner of territorial contests?

Males of many animal species show intraspecific disputes for mating territories that range from displays without physical contact to physical fights with risk of injury. This variation motivated the proposition of different models that suggest possible rules used by rivals to decide the contest winner. To evaluate those models, it is necessary to identify how males behave during the fight and the individual attributes that determine their fighting ability (resource holding potential). For this, males of the dragonfly Macrothemis imitans (Karsch) (Odonata: Libellulidae) were used to evaluate two hypotheses conditioned on the occurrence of physical contact during the fight: if the contests occur with physical contact, features related to size should determine male resource holding potential, and if males do not exhibit physical contact during the contests, features that confer greater endurance should determine resource holding potential. To assess these hypotheses, we collected males that had ownership of territories (resident males) and males that occupied the territory after we removed the resident males (substitute males). After the capture, the resident and substitute males were transferred to the laboratory for measurements of wing area, dry weight, thoracic muscle mass, and fat content. The results showed that resident males do not differ in any measured trait from substitutes. Because the fights occur with physical contact, it is intriguing that resident males do not possess higher fighting capacity than intruders. Perhaps physical contact does not incur high costs during the fight, and other asymmetries, such as motivation associated with prior residency of the disputed territory, determine the contest winner.

Impact of coagulation in the development of thromboembolic events in patients with spinal cord injury.

STUDY DESIGN: Although the knowledge described about risk factors and venous thromboembolism (VT) in the general population, the impact of these factors in the development of thromboembolic events in patients with spinal injury (SI) caused by spinal cord injury (SCI) is poorly understood. OBJECTIVE: Evaluate the impact of risk factors in the development of thromboembolic events in patients with SCI. SETTING: Brazil, São Paulo. METHODS: Observational, prospective and cross-study. Eligible patients (n=100) had SI by SCI, >18 years. The degree of motor and sensory lesion was evaluated based on American Spinal Injury Association (ASIA) Impairment Scale (AIS). Blood samples were collected for coagulation exams, hemogram, laboratory and biochemical analyses. Ultrasonography analyzes were performed from deep and superficial venous systems of lower limbs. Quantitative real-time PCR experiments were performed in order to investigate mutations in the prothrombin (G20210A) and Leiden factor V (G1691A) genes. RESULTS: The main finding of this study was the higher occurrence of deep venous thrombosis (DVT) in patients with Leiden factor V and hyperhomocysteinemia. There was no association between SI for DVT, VT and thrombophilia. Also, there was no relation between lupus anticoagulant and anti-cardiolipin. CONCLUSION: There is an important difference in the incidence of DVT in patients with SI by acute and chronic SCI. Therefore, the conduct of the investigation for thrombophilia should be based on clinical factors, risk factors for DVT and family history of thrombosis.

Diversity of the ground-dwelling ant fauna (Hymenoptera: Formicidae) of a moist, montane forest of the semi-arid Brazilian Nordeste

Although the so called "green islands" of the semi-arid Brazilian "Nordeste" are economically, socially, and ecologically important, relatively little is known about their biodiversity. We present the results of the first survey of the ground-dwelling ant fauna of a secondary forest in the Serra de Baturité (4° 05’ - 4° 40’ S / 38° 30’ - 39° 10’ W), among the biggest of the moist, montane forests of the state of Ceará, Brazil. From February to March 2001, samples were taken every 50 m along twelve 200 m transects, each separated from the others by at least 50 m and cut on either side of a recreational trail. Where possible, two transects were cut from the same starting point on the trail, one on either side. At each sample site two methods were used, as recommended in the ALL protocol: a pitfall trap and the treatment of 1 m² of leaf litter with the Winkler extractor. The myrmecofauna of the Serra de Baturité is quite diverse: individuals from 72 species, 23 genera, and six subfamilies were collected. The observed patterns of specific richness show the same tendencies noted in other tropical regions, particularly the frequency of capture distribution with many rare and few abundant species. Differences with the Atlantic and Amazonian forests were also observed, especially the relative importance of the Ponerinae and Formicinae subfamilies, indicating a possible influence of the surrounding "caatinga" (savanna-like ecosystem) on the myrmecofauna of the moist, montane forest

Se presentan los resultados del primer inventario de la mirmecofauna del suelo en un parche de bosque montano húmedo del "Nordeste" semi-árido brasileño. Aunque estos parches o "islas verdes" son importantes económica, social, y ecológicamente, se conoce relativamente poco acerca de su biodiversidad. La investigación fue llevada a cabo en un bosque secundario en la Serra de Baturité, uno de los mayores del bosque montano húmedo del estado de Ceará, Brazil. La mirmecofauna de Serra de Baturité es muy diversa: encontramos individuos de 72 especies, 23 géneros y seis fsubfamilias. Los patrones de riqueza específica muestran las mismas tendencias de otras regiones tropicales, particularmente en la distribución de frecuencia de capturas, con muchas especies escasas y unas pocas especies abundantes. También hay diferencias con los bosques atlántico y amazónico, especialmente en cuanto a la importancia relativa de las subfamilias Ponerinae y Formicinae, lo que indica una posible influencia de la "caatinga" (ecosistema semejante a la sabana) cercana en la mirmecofauna del bosque montano húmedo

Diversity of the ground-dwelling ant fauna (Hymenoptera: Formicidae) of a moist, Montane forest of the semi-arid Brazilian "Nordeste".

Although the so called "green islands" of the semi-arid Brazilian "Nordeste" are economically, socially, and ecologically important. relatively little is known about their biodiversity. We present the results of the first survey of the ground-dwelling ant fauna of a secondary forest in the Serra de Baturité (4 degrees 05'-4 degrees 40' S / 38 degrees 30'-39 degrees 10' W), among the biggest of the moist, montane forests of the state of Ceará, Brazil. From February to March 2001, samples were taken every 50 m along twelve 200 m transects, each separated from the others by at least 50 m and cut on either side of a recreational trail. Where possible, two transects were cut from the same starting point on the trail, one on either side. At each sample site two methods were used, as recommended in the ALL. protocol: a pitfall trap and the treatment of 1 m2 of leaf litter with the Winkler extractor. The myrmecofauna of the Serra de Baturité is quite diverse: individuals from 72 species, 23 genera, and six subfamilies were collected. The observed patterns of specific richness show the same tendencies noted in other tropical regions, particularly the frequency of capture distribution with many rare and few abundant species. Differences with the Atlantic and Amazonian forests were also observed, especially the relative importance of the Ponerinac and Formicinae subfamilies, indicating a possible influence of the surrounding "caatinga" (savanna-like ecosystem) on the myrmecofauna of the moist, montane forest.

Morte súbita de caprinos por enterotoxemia / Sudden death of goats due to enterotoxaemia

Descreve-se a ocorrência de morte súbita observada em uma criaçäo de caprinos. A maioria das mortes ocorreu sem qualquer manifestaçäo sintomática prévia; entretanto, em alguns casos observou-se incoordenaçäo motora, eliminaçäo de cíbalas envoltas em fragmentos de mucosa intestinal e diarréia. Nos momentos que antecediam à morte, alguns animais emitiam fortes berros. O isolamento de um bacilo anaeróbio, Gram-positivo e bioquimicamente identificado como Clostridium perfringens, foi possível a partir de amostras de materiais coletadas em diferentes porçöes dos intestinos, retículo e também da raçäo. Nos filtros obtidos dos conteúdos dos órgäos citados, evidenciou-se a presença, em alta dosagem, de uma toxina termolábil e letal para camundongos. A necrópsia, observaram-se compartimentos gástricos plenos de alimento e hemorragias na mucosa intestinal. Estas constataçöes, associadas aos resultados laboratoriais, possibilitaram concluir tratar-se de um quadro de enterotoxemia