Chronux is an open-source software package developed for the analysis of neural data. The current version of Chronux includes software for signal processing of neural time-series data including several specialized mini-packages for spike sorting, local regression, audio segmentation, and other data-analysis tasks typically encountered by a neuroscientist. Chronux is freely available along with user tutorials, sample data, and extensive documentation from http://chronux.org/.

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. These changes in leaf CO 2 concentrations occur as a result of photosynthesis and respiration. Furthermore, atmospheric CO 2 is predicted to double in the present century (1). Many studies have been carried out to determine the effects of atmospheric CO 2 increases on plant gas exchange, carbon fixation, and growth and the resulting impact this will have on natural and agricultural ecosystems (2-6). One of the mechanisms by which increased atmospheric CO 2 affects plants is CO 2 regulation of stomatal apertures. Reports show that a doubling of atmospheric [CO 2 ] causes significant stomatal closure by 20-40% in diverse plant species (7-9).Stomata experience diurnal changes in [CO 2 ] inside the leaf during light͞dark transitions. In the dark, CO 2 is produced in leaves by cellular respiration. The [CO 2 ] shifts caused by illumination changes are rapid and large, with [CO 2 ] in the stomatal cavity ranging from 200 to 650 ppm (10).Stomatal aperture is controlled by the turgor pressure in the guard cells surrounding the stomatal pore. Guard cell turgor pressure is mediated by the ion and organic solute concentration in guard cells. Elevated CO 2 has been shown to enhance potassium efflux channel and S type anion channel activities that mediate extrusion of ions during stomatal closure (11,12). In correlation with these findings, chloride release from guard cells is triggered by CO 2 elevation (13), and high CO 2 causes depolarization of guard cells (14, 15). Furthermore, CO 2 activation of R type anion channel currents was found in a subset of Vicia faba guard cells (12).Little is known about the CO 2 signal transduction mechanisms that function upstream of ion channels in guard cells (16)(17)(18)(19). CO 2 -induced stomatal movements were previously found to be absent in two mutants that affect the stomatal closure signaling network for the drought stress hormone abscisic acid (ABA): abi1-1 and abi2-1 (20). Conditional CO 2 responsiveness was reported in these mutants by using different experimental conditions (21,22 (16-18, 24, 26-32). Furthermore, some studies have also indicated a role for calcium increases in the opposing response of stomatal opening (33)(34)(35). It is unclear how these opposite responses could be directed via elevations in the same second messenger, Ca 2ϩ .CO 2 is a particularly interesting stomatal stimulus with respect to cytosolic Ca 2ϩ responses, as demonstrated in the present study. CO 2 can induce stomatal opening or closing depending on its concentration (36). Studies in animal and plant cells have shown that different patterns of repetitive calcium transients modulate responses (29,(37)(38)(39). Although previous studies have shown a role for calcium in CO 2 signaling in guard cells (24,25), changes in repetitive calcium transient patterns have not yet been studied in guard cells in response to CO 2 . The present study demonstrates CO 2 modulation of repetitive calcium transient patterns in Arabidopsis guard cells and characterizes roles of Ca 2ϩ in CO 2 -regulated stomatal ope...

In early 2018 Nigeria experienced an unprecedented increase in Lassa fever cases with widespread geographic distribution. We report 77 Lassa virus genomes generated from patient samples, 14 from 2018, to investigate whether recent changes in the virus genome contributed to this surge. Our data argue that the surge is not attributable to a single Lassa virus variant, nor has it been sustained by human-to-human transmission. We observe extensive viral diversity structured by geography, with major rivers appearing to act as barriers to migration of the rodent reservoir. Together our results support that the 2018 Lassa fever surge was driven by crossspecies transmission from local rodent populations of multiple viral variants from different lineages.