109 research outputs found
Ertragsbildung von unterschiedlichen Kulturarten für die Biogaserzeugung im ökologischen Landbau
Energy crops for biogas production need to be integrated into sustainable and site
adapted crop rotation systems, minimising the competition with food production.
Luzerne/clover (-grass), sun flower, maize, green-rye + maize and vetch-rye + maize
were compared at two sites in Austria with semi-arid (Raasdorf) and humid (Lambach)
conditions with and without biogas slurry application. The yield of legumes and
fertilised non-legumes at the humid site were 9 % to 56 % higher then at the semi-arid
site. The 2-crop system maize following vetch-rye achieved the highest yields at both
sites. Slurry from the biogas plant increased the yield only at the humid site
Big Food, Food Systems, and Global Health
In an article that forms part of the PLoS Medicine series on Big Food, guest editors David Stuckler and Marion Nestle lay out why more examination of the food industry is necessary, and offer three competing views on how public health professionals might engage with Big Food
A new large-bodied oviraptorosaurian theropod dinosaur from the Latest Cretaceous of Western North America
The oviraptorosaurian theropod dinosaur clade Caenagnathidae has long been enigmatic due to the incomplete nature of nearly all described fossils. Here we describe Anzu wyliei gen. et sp. nov., a new taxon of large-bodied caenagnathid based primarily on three well-preserved partial skeletons. The specimens were recovered from the uppermost Cretaceous (upper Maastrichtian) Hell Creek Formation of North and South Dakota, and are therefore among the stratigraphically youngest known oviraptorosaurian remains. Collectively, the fossils include elements from most regions of the skeleton, providing a wealth of information on the osteology and evolutionary relationships of Caenagnathidae. Phylogenetic analysis reaffirms caenagnathid monophyly, and indicates that Anzu is most closely related to Caenagnathus collinsi, a taxon that is definitively known only from a mandible from the Campanian Dinosaur Park Formation of Alberta. The problematic oviraptorosaurs Microvenator and Gigantoraptor are recovered as basal caenagnathids, as has previously been suggested. Anzu and other caenagnathids may have favored well-watered floodplain settings over channel margins, and were probably ecological generalists that fed upon vegetation, small animals, and perhaps eggs
Reptilian Heart Development And The Molecular Basis Of Cardiac Chamber Evolution
The emergence of terrestrial life witnessed the need for more sophisticated circulatory systems. This has evolved in birds, mammals and crocodilians into complete septation of the heart into left and right sides, allowing separate pulmonary and systemic circulatory systems, a key requirement for the evolution of endothermy(1-3). However, the evolution of the amniote heart is poorly understood. Reptilian hearts have been the subject of debate in the context of the evolution of cardiac septation: do they possess a single ventricular chamber or two incompletely septated ventricles(4-7)? Here we examine heart development in the red-eared slider turtle, Trachemys scripta elegans (a chelonian), and the green anole, Anolis carolinensis (a squamate), focusing on gene expression in the developing ventricles. Both reptiles initially form a ventricular chamber that homogenously expresses the T-box transcription factor gene Tbx5. In contrast, in birds and mammals, Tbx5 is restricted to left ventricle precursors(8,9). In later stages, Tbx5 expression in the turtle (but not anole) heart is gradually restricted to a distinct left ventricle, forming a left-right gradient. This suggests that Tbx5 expression was refined during evolution to pattern the ventricles. In support of this hypothesis, we show that loss of Tbx5 in the mouse ventricle results in a single chamber lacking distinct identity, indicating a requirement for Tbx5 in septation. Importantly, misexpression of Tbx5 throughout the developing myocardium to mimic the reptilian expression pattern also results in a single mispatterned ventricular chamber lacking septation. Thus ventricular septation is established by a steep and correctly positioned Tbx5 gradient. Our findings provide a molecular mechanism for the evolution of the amniote ventricle, and support the concept that altered expression of developmental regulators is a key mechanism of vertebrate evolution
Climate-mediated diversification of turtles in the Cretaceous
The file attached is the published version of the article
Who decides what is fair in fair trade? The agri-environmental governance of standards, access, and price
The agri-environmental governance of value chains can favour a Polanyian double movement seeking social protection and control over price setting markets or it can advance a neoliberal logic that strives to overcome the few remaining civic and ecologic obstacles to full market dominance. Coupled with a typology that contrasts corporate social responsibility and social economy Fair Trade models, this theoretical framework elucidates positions in the current policy debates about the minimum coffee price standard. Many Southern smallholders consider Fair Trade's standards, which for coffee include direct market accesses for smallholder cooperatives, minimum prices, and environmental criteria, among the best deals available. The smallholder empowerment benefits are often better than competing eco-labels. However, this study finds that Fair Trade minimum prices lost 41 percent of their real value from 1988 to 2008. Despite objections from several 'market driven' firms and national labelling initiatives, smallholders' collective advocacy and this research contributed to the Fairtrade Labelling Organisations International's (FLO) decision to mandate a 7-11 percent minimum price increase. The price debates demonstrate that Fair Trade governance is neither purely neoliberal nor social movement led - it is a highly contested socially embedded practice. Voices without votes, North-South inequalities, and dwindling prices paid to its stated protagonists indicate the need for governance reform, cost of living price adjustments, and additional investment in the innovative alternative trade and hybrid models
A toothed turtle from the Late Jurassic of China and the global biogeographic history of turtles
Turtles (Testudinata) are a successful lineage of vertebrates with about 350 extant species that inhabit all major oceans and landmasses with tropical to temperate climates. The rich fossil record of turtles documents the adaptation of various sub- lineages to a broad range of habitat preferences, but a synthetic biogeographic model is still lacking for the group.Results: We herein describe a new species of fossil turtle from the Late Jurassic of Xinjiang, China, Sichuanchelys palatodentata sp. nov., that is highly unusual by plesiomorphically exhibiting palatal teeth. Phylogenetic analysis places the Late Jurassic Sichuanchelys palatodentata in a clade with the Late Cretaceous Mongolochelys efremovi outside crown group Testudines thereby establishing the prolonged presence of a previously unrecognized clade of turtles in Asia, herein named Sichuanchelyidae. In contrast to previous hypotheses, M. efremovi and Kallokibotion bajazidi are not found within Meiolaniformes, a clade that is here reinterpreted as being restricted to Gondwana.Conclusions: A revision of the global distribution of fossil and recent turtle reveals that the three primary lineages of derived, aquatic turtles, including the crown, Paracryptodira, Pan-Pleurodira, and Pan- Cryptodira can be traced back to the Middle Jurassic of Euramerica, Gondwana, and Asia, respectively, which resulted from the primary break up of Pangaea at that time. The two primary lineages of Pleurodira, Pan-Pelomedusoides and Pan-Chelidae, can similarly be traced back to the Cretaceous of northern and southern Gondwana, respectively, which were separated from one another by a large desert zone during that time. The primary divergence of crown turtles was therefore driven by vicariance to the primary freshwater aquatic habitat of these lineages. The temporally persistent lineages of basal turtles, Helochelydridae, Meiolaniformes, Sichuanchelyidae, can similarly be traced back to the Late Mesozoic of Euramerica, southern Gondwana, and Asia. Given the ambiguous phylogenetic relationships of these three lineages, it is unclear if their diversification was driven by vicariance as well, or if they display a vicariance-like pattern. The clean, primary signal apparent among early turtles is secondarily obliterated throughout the Late Cretaceous to Recent by extensive dispersal of continental turtles and by multiple invasions of marine habitats
A nomenclature for fossil and living turtles using phylogenetically defined clade names
Over the last 25Â years, researchers, mostly paleontologists, have developed a system of rank-free, phylogenetically defined names for the primary clades of turtles. As these names are not considered established by the PhyloCode, the newly created nomenclatural system that governs the naming of clades, we take the opportunity to convert the vast majority of previously defined clade names for extinct and extant turtles into this new nomenclatural framework. Some previously defined names are converted with minor adjustments. We also define a number of new clade names to close apparent nomenclatural gaps. In total, we establish 113 clade names, of which 79 had already received phylogenetic definitions and 34 are new
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