Publications by authors named "Claire Nichols"

The Western United States is experiencing historic drought, increasing pressure on water management systems. Agricultural production that relies on surface water flows is therefore imperiled, requiring new innovations and partnerships in order to adapt and survive. In Arizona, some agriculture continues to rely on historic, low-tech irrigation infrastructure such as hand-dug open ditches that divert river water to flood fields.

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In recent decades, the number of farmers markets has increased dramatically across the country. Though farmers markets have been described as White spaces, they can play important roles in reducing food insecurity. It is particularly true in Michigan, where farmers markets were crucial collaborators in pioneering programs such as Double-Up Food Bucks that help low-income residents and people of color gain access to fresh, healthy, locally grown food.

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We report paleomagnetic data showing that an intraoceanic Trans-Tethyan subduction zone existed south of the Eurasian continent and north of the Indian subcontinent until at least Paleocene time. This system was active between 66 and 62 Ma at a paleolatitude of 8.1 ± 5.

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Magnetic measurements of the lunar crust and Apollo samples indicate that the Moon generated a dynamo magnetic field lasting from at least 4.2 until <2.5 billion years (Ga) ago.

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SgrAI is a type II restriction endonuclease with an unusual mechanism of activation involving run-on oligomerization. The run-on oligomer is formed from complexes of SgrAI bound to DNA containing its 8 bp primary recognition sequence (uncleaved or cleaved), and also binds (and thereby activates for DNA cleavage) complexes of SgrAI bound to secondary site DNA sequences which contain a single base substitution in either the 1st/8th or the 2nd/7th position of the primary recognition sequence. This modulation of enzyme activity via run-on oligomerization is a newly appreciated phenomenon that has been shown for a small but increasing number of enzymes.

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Palaeomagnetic measurements of meteorites suggest that, shortly after the birth of the Solar System, the molten metallic cores of many small planetary bodies convected vigorously and were capable of generating magnetic fields. Convection on these bodies is currently thought to have been thermally driven, implying that magnetic activity would have been short-lived. Here we report a time-series palaeomagnetic record derived from nanomagnetic imaging of the Imilac and Esquel pallasite meteorites, a group of meteorites consisting of centimetre-sized metallic and silicate phases.

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Background And Purpose: Current knowledge states that vasoconstrictor responses to ATP are mediated by rapidly desensitizing ligand-gated P2X1 receptors in vascular smooth muscle cells (VSMCs). However, ATP is implicated in contributing to pathological conditions involving sustained vasoconstrictor response such as cerebral vasospasm. The purpose of this study is to test the hypothesis that the stimulation of VSMC P2XR receptors (P2XRs) contributes to ATP-evoked sustained vasoconstrictions in rat middle cerebral arteries (RMCAs).

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Stimulation of P2X receptors by ATP in vascular smooth muscle cells (VSMCs) is proposed to mediate vascular tone. However, understanding of P2X receptor-mediated actions in human blood vessels is limited, and therefore, the current work investigates the role of P2X receptors in freshly isolated small human gastro-omental arteries (HGOAs). Expression of P2X1 and P2X4 receptor subunit messenger RNA (mRNA) and protein was identified in individual HGOA VSMCs using RT-PCR and immunofluorescent analysis and using Western blot in multi-cellular preparations.

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