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Antagonists of Wnt and BMP signaling promote the formation of vertebrate head muscle
(Cold Spring Harbor Laboratory Press, 2003)
Recent studies have postulated that distinct regulatory cascades control myogenic differentiation in the head and the trunk. However, although the tissues and signaling molecules that induce skeletal myogenesis in the trunk ...
The genetic basis of adaptive melanism in pocket mice
(Proceedings of the National Academy of Sciences, 2003)
Identifying the genes underlying adaptation is a major challenge in evolutionary biology. Here, we describe the molecular changes underlying adaptive coat color variation in a natural population of rock pocket mice, ...
Vase-shaped Microfossils from the Neoproterozoic Chuar Group, Grand Canyon: A Classification Guided by Modern Testate Amoebae
(Society of Economic Paleontologists and Mineralogists, 2003)
Vase-shaped microfossil (VSM) assemblages front early diagenetic carbonate nodules in >742 +/- 6 Ma black shales of the Chuar Group, Grand Canyon, provide evidence for affinities with testate amoebae. Not only are VSMs ...
Stomatal Closure During Leaf Dehydration, Correlation with Other Leaf Physiological Traits
(American Society of Plant Biologists, 2003)
The question as to what triggers stomatal closure during leaf desiccation remains controversial. This paper examines characteristics of the vascular and photosynthetic functions of the leaf to determine which responds most ...
Molar Tooth Structures in Calcareous Nodules, Early Neoproterozoic Burovaya Formation, Turukhansk Region, Siberia
(Elsevier, 2003)
Molar tooth structures are abundant in large (1-2 m diameter) carbonate nodules within fine-grained, subtidal carbonates of the early Neoproterozoic (lower Upper Riphean) Burovaya Formation along the Sukhaya Tunguska River, ...
The NASA Astrobiology Roadmap
(Mary Ann Liebert, Inc., 2003)
The NASA Astrobiology Roadmap provides guidance for research and technology development across the NASA enterprises that encompass the space, Earth, and biological sciences. The ongoing development of astrobiology roadmaps ...
Recognizing and Interpreting the Fossils of Early Eukaryotes
(Springer Verlag, 2003)
Using molecular sequence data, biologists can generate hypotheses of protistan phylogeny and divergence times. Fossils, however, provide our only direct constraints on the timing and environmental context of early eukaryotic ...
Scaling Phloem Transport: Water Potential Equilibrium and Osmoregulatory Flow
(Blackwell Publishing, 2003)
In this work, the common assumption that phloem sap is in water potential equilibrium with the surrounding apoplast was examined. With a dimensionless model of phloem translocation that scales with just two dimensionless ...
Patterns of Variation in MHC Class II Beta Loci of the Little Greenbul (Andropadus virens) with Comments on MHC Evolution in Birds
(Blackwell Publishing, 2003)
The hydraulic conductance of leaves (k<sub>leaf</sub>) was examined to determine whether this little understood component of the water transport pathway plays a role in governing leaf phenology of two deciduous dry forest ...
The Major Veins of Mesomorphic Leaves Revisited: Tests for Conductive Overload in Acer saccharum (Aceraceae) and Quercus rubra (Fagaceae)
(Botanical Society of America, 2003)
Many leaves survive the severing of their major veins in apparently excellent health. According to the classical explanation, the leaf minor veins provide "conductive overload," an excess of parallel conductive paths, ...