Description: This report describes the findings of a study conducted on the Eastern Watersheds of Lake Lavon, Lake Ray Hubbard, Lake Tawakoni, Lake Palestine and Lake Fork, which are located within the Blackland Prairie, Post Oak Savannah and Pineywoods provinces. These watersheds are among nine that provide drinking water to Dallas, Texas. The study examines the potential benefit of "remote sensing and geographic information systems (GIS) for watershed management" in these five watersheds (p. iii).

Description: This article is in response to an authors' reply to 'Use of prior odds for missing persons identifications.' This response is to the reply by Alex Biedermann, Franco Taroni, and Pierre Margot.

Description: This article discusses the role of hypoxia in the evolution and development of the cardiovascular system. How multicellular organisms obtain and use oxygen and other substrates has evolved over hundreds of millions of years in parallel with the evolution of oxygen-delivery systems. A steady supply of oxygen is critical to the existence of organisms that depend on oxygen as a primary source of fuel (i.e., those that live by aerobic metabolism). Not surprisingly, a number of mechanisms have evolved to defend against oxygen deprivation. This review highlights evolutionary and developmental aspects of O(2) delivery to allow understanding of adaptive responses to O(2) deprivation (hypoxia). First, the authors consider how the drive for more efficient oxygen delivery from the heart to the periphery may have shaped the evolution of the cardiovascular system, with particular attention to the routing of oxygenated and deoxygenated blood in the cardiac outlet. Then the authors consider the role of O(2) in the morphogenesis and the cardiovascular system of animals of increasing size and complexity. The authors conclude by suggesting areas for future research regarding the role of oxygen deprivation and oxidative stress in the normal development of the heart and vascular or in the pathogenesis of ...

Description: This article discusses symplastic continuity between companion cells and the translocation stream. Substantial symplastic continuity appears to exist between companion cells (CCs) and sieve elements of the phloem, which suggests that small solutes within the CC are subject to indiscriminate long-distance transport via the translocation stream. To test this hypothesis, the distributions of exotic and endogenous solutes synthesized in the CCs of minor veins were studied. Octopine, a charged molecule derived from arginine and pyruvate, was efficiently transported through the phloem but was also transferred in substantial amounts to the apoplast, and presumably other non-phloem compartments. The disaccharide galactinol also accumulated in non-phloem compartments, but long-distance transport was limited. Conversely, sucrose, raffinose, and especially stachyose demonstrated reduced accumulation and efficient transport out of the leaf. The authors conclude that small metabolites in the cytosol of CCs do enter the translocation stream indiscriminately but are also subject to distributive forces, such as nonselective and carrier-mediated membrane transport and symplastic dispersal, that may effectively clear a compound from the phloem or retain it for long-distance transport. A model is proposed in which the transport or oligosaccharides is an adaptive strategy to improve photoassimilate retention, and consequently translocation efficiency, the phloem.

Description: This article accompanies a poster presentation on temporal associative memory (TAM). Spike-timing synaptic plasticity (STDP) describes the increase and decrease in synaptic strength depending on the relative arrival time of the pre- and post-synaptic spikes. The relative timing that determines whether the synapse is strengthened by long-term potentiation (LTP), or weakened by long-term depression (LTD) was first reported experimentally and computationally. Because of the asymmetry in timing, it is also called "temporally asymmetric Hebbian plasticity" theoretically. Numerous studies on STDP had explored the biological mechanisms for induction of LTP and LTD. This paper will focus on the computational function of STDP in the formation of temporal associative memory (TAM).