23 research outputs found
ATP synthesis driven by a pH gradient imposed across the cell membranes of lipoic acid and unsaturated fatty acid auxotrophs of escherichia coli
L'edifici té el seu origen a principis del segle XIX.Primer pla, contrapicat, d'un edifici de
planta baixa i quatre plantes pis.
S'estructura segons eixos verticals amb
tres obertures per planta que s'organitzen
com a balconades en els dos primers pisos
i com a balcons en els restants
Reconstructing the nonadaptive radiation of an ancient lineage of ground‐dwelling stick insects (Phasmatodea: Heteropterygidae)
Stick and leaf insects (Phasmatodea) are large terrestrial herbivorous arthropods known for masquerading as plant parts such as bark, twigs and leaves. Their evolutionary history is largely shaped by convergent evolution associated with adaptive radiations on geographically isolated landmasses that have repeatedly generated ground-dwelling ecomorphs. The members of one lineage, however, the Oriental Heteropterygidae, are morphologically rather uniform, and have a predominantly ground-dwelling lifestyle. The phylogeny of Heteropterygidae that comprises approximately 130 described species is controversial and remains uncertain. In particular, the systematic position of the giant Jungle Nymph Heteropteryx dilatata, whose males are capable of flight and exhibit the most plesiomorphic wing morphology among extant phasmatodeans, is of major interest to the scientific community. Here, we analysed a set of seven nuclear and mitochondrial genes to infer the phylogeny of Heteropterygidae covering the group's overall diversity. The divergence time estimation and reconstruction of the historical biogeography resulted in an ancestral distribution across Sundaland with long distance dispersal events to Wallacea, the Philippines and the South Pacific. We were able to resolve the relationships among the three principal subgroups of Heteropterygidae and revealed the Dataminae, which contain entirely wingless small forms, as the sister group of Heteropteryginae + Obriminae. Within Heteropteryginae, Haaniella is recovered as paraphyletic in regard to Heteropteryx. Consequently, Heteropteryx must be considered a subordinate taxon deeply embedded within a flightless clade of stick insects. Within Obriminae, the Bornean Hoploclonia is strongly supported as the earliest diverging lineage. Based on this finding, we recognize only two tribes of equal rank among Obriminae, the Hoplocloniini trib. nov. and Obrimini sensu nov. Within the latter, we demonstrate that previous tribal assignments do not reflect phylogenetic relationships and that a basal splitting event occurred between the wing-bearing clade Miroceramia + Pterobrimus and the remaining wingless Obrimini. The Philippine genus Tisamenus is paraphyletic with regard to Ilocano hebardi, thus, we transfer the latter species to Tisamenus as Tisamenus hebardi comb. nov. and synonymize Ilocano with Tisamenus. We discuss character transformations in the light of the new phylogenetic results and conclude that the current taxonomic diversity appears to be mainly driven by allopatry and not to be the result of niche differentiation. This radiation is thus best described as a nonadaptive radiation
Peat in horticulture and conservation: the UK response to a changing world
Peat bogs are increasingly recognised as valuable habitats for wildlife and important stores of carbon. Yet the UK horticultural industry relies heavily on peat sourced from bogs in the UK and Republic of Ireland. Environmentalists, government and horticultural businesses in the UK now recognise the environmental consequences of using peat in horticulture, and the industry is turning increasingly to sustainable raw materials. In this paper, the strengths and weaknesses of campaigning since 1990 to implement this change are analysed, with the intention of providing useful information for other countries facing similar challenges. The campaign encountered deeply-ingrained practices so that the shift in behaviour has been slow and, although now widespread, still meets resistance in some quarters. The UK Government introduced targets for peat replacement which have helped stimulate the industry to develop suitable alternatives. The major gardening retailers have included peat replacement targets in their environmental codes of practice, and these are being met through incremental peat dilution with alternative materials such as green compost and processed timber by-products. Legislative requirements for European biodiversity conservation have led the UK government to terminate peat extraction on significant areas of former commercial extraction. The importance of peatlands for carbon sequestration and the major issue of climate change are increasingly focusing attention on peatland conservation, pointing towards the need for a more consistent approach to the use of peat across the European Community