Most studies dealing with species distribution patterns on fragmented landscapes focus on the characteristics of habitat patches that influence local occurrence and abundance, but they tend to neglect the question of what drives colonization of previously unoccupied patches. In a study of the dryad butterfly, we combined classical approaches derived from metapopulation theory and landscape ecol...

dopamine (da) is one of the main catecholamines in the brain and is crucial for movement coordination, endocrine function, reward, mood, memory and emotions. the dopaminergic system is the primary therapeutic target in the treatment of parkinson’s disease (pd), drug addiction and schizophrenia. notwithstanding, dysfunction of central dopaminergic neurotransmission has also been associated to de...

Atomic hydrogen adsorption energies on bimetallic overlayer systems have been determined by periodic density functional theory calculations within the generalized gradient approximation. On the pseudomorphic Pd/Cu(111) surface, both the substrate interaction and the lattice compression of the Pd overlayer lead to smaller hydrogen binding energies. For pseudomorphic Cu/Pd(111), on the hand, the ...

BACKGROUND The total amount of native vegetation is an important property of fragmented landscapes and is known to exert a strong influence on population and metapopulation dynamics. As the relationship between habitat loss and local patch and gap characteristics is strongly non-linear, theoretical models predict that immigration rates should decrease dramatically at low levels of remaining nat...

The interactive effects of predator density and prey distribution on the foraging behavior of an important estuarine predator were studied, at a fine temporal scale, using ultrasonic telemetry. The movement and agonistic activity of individual blue crabs Callinectes sapidus were monitored in large field enclosures, in which the density of crabs and the distribution of patches of bivalve prey Ma...

BACKGROUND patients with Parkinson's disease (PD) have a high risk of sustaining osteoporotic fractures as a result of falls and reduced bone mass. OBJECTIVE to summarise the underlying pathophysiological mechanisms of bone loss in PD by reviewing the available literature. METHODS a Medline search was performed for articles published between January 1975 and January 2011, using the keywords...

Depression, anxiety and apathy are common mood disturbances in Parkinson's disease (PD) but their pathophysiology is unclear. Advanced neuroimaging has been increasingly used to unravel neural substrates linked to these disturbances. A systematic review is provided of neuroimaging findings in depression, anxiety and apathy in PD. A PubMed, MEDLINE and EMBASE search of peer-reviewed original res...

OBJECTIVES Parkinson's disease (PD) and osteoporosis are two common chronic disabling conditions in older adults that adversely affect quality of life. The aim of the present work was to study the relationship between bone changes and PD. METHODS eighty-two patients with established PD aged 65 years or older and 68 age-, sex- and body mass index (BMI)-matched healthy control subjects were rec...

Ultrasmall and uniform Pd6Co nanocrystals were deposited on 3D graphene by a facile one-pot surfactant-free route for a catalyst toward formic acid oxidation, showing a much higher electrocatalytic activity, larger peak current density and better stability than Pd/3DG, Pd/C as well as commercial Pd-C, and thus offering great potential for an efficient anode catalyst toward high performance dire...