24,220 research outputs found
Experimental Basis and First Application of CLinical Lymphvessel-Transplantation of Secondary Lamphedema
Chebychev Trajectory Optimization Program /CHEBYTOP/ Final report
Digital computer program for interplanetary trajectory optimization and variable thrust dat
Ground state and constrained domain walls in Gd/Fe multilayers
The magnetic ground state of antiferromagnetically coupled Gd/Fe multilayers
and the evolution of in-plane domain walls is modelled with micromagnetics. The
twisted state is characterised by a rapid decrease of the interface angle with
increasing magnetic field. We found that for certain ratios M(Fe):M(Gd), the
twisted state is already present at low fields. However, the magnetic ground
state is not only determined by the ratio M(Fe):M(Gd) but also by the
thicknesses of the layers, that is the total moments of the layer. The
dependence of the magnetic ground state is explained by the amount of overlap
of the domain walls at the interface. Thicker layers suppress the Fe aligned
and the Gd aligned state in favour of the twisted state. Whereas ultrathin
layers exclude the twisted state, since wider domain walls can not form in
these ultrathin layers
Allometric growth in the Diademodontinae (Reptilia; Therapsida); a preliminary report
Main articleThe hypothesis that many, if not all, of the South African and Zambian specimens, which have
been regarded as different diademodontine genera and species, actually consitute a taxonomically
homogeneous, ontogenetic growth series is tested. The principles of allometric growth were
applied to this sample of fossils, which varied considerably in size and shape. The approach
which was followed was exclusively morphometric. The results indicate that these specimens do
represent various ontogenetic stages of a growth series of only a single species of Diademodon
Seeley.Non
Multilocus Genetic Investigation of Species Limits in the Caddo Mountain Salamander (Plethodon caddoensis)
Alexandra D. Hahn is an undergraduate student in the School of Biological Sciences at Louisiana Tech University.
Donald B. Shepard is an Assistant Professor in the School of Biological Sciences at Louisiana Tech University
Preliminary Solar Sail Design and Fabrication Assessment: Spinning Sail Blade, Square Sail Sheet
Blade design aspects most affecting producibility and means of measurement and control of length, scallop, fullness and straightness requirements and tolerances were extensively considered. Alternate designs of the panel seams and edge reinforcing members are believed to offer advantages of seam integrity, producibility, reliability, cost and weight. Approaches to and requirements for highly specialized metalizing methods, processes and equipment were studied and identified. Alternate methods of sail blade fabrication and related special machinery, tooling, fixtures and trade offs were examined. A preferred and recommended approach is also described. Quality control plans, inspection procedures, flow charts and special test equipment associated with the preferred manufacturing method were analyzed and are discussed
Coping with multiple enemies : pairwise interactions do not predict evolutionary change in complex multitrophic communities
Predicting the ecological and evolutionary trajectories of populations in multispecies communities is one of the fundamental challenges in ecology. Many of these predictions are made by scaling patterns observed from pairwise interactions. Here, we show that the coupling of ecological and evolutionary outcomes is likely to be weaker in increasingly complex communities due to greater chance of life-history trait correlations. Using model microbial communities comprising a focal bacterial species (Bacillus subtilis), a bacterial competitor, protist predator and phage parasite, we found that increasing the number of enemies in a community had an overall negative effect on B. subtilis population growth. However, only the competitor imposed direct selection for B. subtilis trait evolution in pairwise cultures and this effect was weakened in the presence of other antagonists that had a negative effect on the competitor. In contrast, adaptation to parasites was driven indirectly by correlated selection where competitors had a positive and predators a negative effect. For all measured traits, selection in pairwise communities was a poor predictor of B. subtilis evolution in more complex communities. Together, our results suggest that coupling of ecological and evolutionary outcomes is interaction-specific and weakly coupled in more complex communities. We conclude that understanding 2 the ecological and evolutionary mechanisms underpinning trait correlations is crucial to predict species response to global change in complex microbial communitie
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