988 resultados para 1055
Resumo:
Vicariance is thought to have played a major role in the evolution of modern parrots. However, as the relationships especially of the African taxa remained mostly unresolved, it has been difficult to draw firm conclusions about the roles of dispersal and vicariance. Our analyses using the broadest taxon sampling of old world parrots ever based on 3219 bp of three nuclear genes revealed well-resolved and congruent phylogenetic hypotheses. Agapornis of Africa and Madagascar was found to be the sister group to Loriculus of Australasia and Indo-Malayasia and together they clustered with the Australasian Loriinae, Cyclopsittacini and Melopsittacus. Poicephalus and Psittacus from mainland Africa formed the sister group Of the Neotropical Arini and Coracopsis from Madagascar and adjacent islands may be the closest relative of Psittrichas from New Guinea. These biogeographic relationships are best explained by independent colonization of the African continent via trans-oceanic dispersal from Australasia and Antarctica in the Paleogene following what may have been vicariance events in the late Cretaceous and/or early Paleogene. Our data support a taxon pulse model for the diversification of parrots whereby trans-oceanic dispersal played a more important role than previously thought and was the prerequisite for range expansion into new continents. (C) 2009 Elsevier Inc. All rights reserved
Resumo:
Two asylum seekers (patient A, 30 year old man from Mongolia; patient B, 18 year old woman from the Sudan) were referred to our outpatient clinic because of acute and chronic deterioration of their general condition and shortness of breath. Both patients presented with a clear clinical picture of systemic venous hypertension and moderate pulmonary congestion. Patient B had a paradoxical pulse compatible to cardiac tamponade.
Resumo:
A longitudinal bone survey was conducted in 86 female Wistar rats in order to assess mineral density kinetics from young age (5 weeks: 115 g) till late adulthood (64 weeks: 586 g). In vivo quantitative radiographic scanning was performed on the caudal vertebrae, taking trabecular mass as the parameter. Measurements were expressed as Relative Optical Density (ROD) units by means of a high resolution densitometric device. Results showed a progressive increase in mineral density throughout the life cycle, with a tendency to level in the higher weight range, indicating that progressive mineral aposition occurs in rats in dependency of age. This phenomenon, however, should be always considered within the context of continuous skeletal growth and related changes typical of this species. Twelve different animals were also examined following induction of articular inflammation with Freund's adjuvant in six of them. Bone survey conducted 12 to 18 days after inoculation revealed a significant (P less than 0.01) reduction in trabecular bone mass of scanned vertebrae in comparison with the weight-matched untreated controls. It is concluded that the in vivo quantitative assessment of bone density illustrated in this report represents a sensitive and useful tool for the long-term survey of naturally occurring or experimentally induced bone changes. Scanning of the same part of the skeleton can be repeated, thereby avoiding sacrifice of the animal and time-consuming preparation of post-mortem material.
Resumo:
Avascular necrosis of the hamate is a very rare condition. After repetitive stress a young male developed left wrist pain which was found to be an avascular necrosis of the hamate. After progression of the necrosis with cyst formation on follow-up magnetic resonance imaging (MRI) and persisting pain, the patient underwent successful revascularisation with a vascular bone graft of the distal radius.
Resumo:
'Early-onset' studies have shown that symptomatic response often occurs early and that early symptomatic response is predictive for later outcome. Limiting factors of these studies include the restriction on symptomatic outcome, the inclusion of mostly moderately ill patients, and the use of various antipsychotics.