18 research outputs found
COSORE: A community database for continuous soil respiration and other soil‐atmosphere greenhouse gas flux data
Globally, soils store two to three times as much carbon as currently resides in the atmosphere, and it is critical to understand how soil greenhouse gas (GHG) emissions and uptake will respond to ongoing climate change. In particular, the soil‐to‐atmosphere CO2 flux, commonly though imprecisely termed soil respiration (RS), is one of the largest carbon fluxes in the Earth system. An increasing number of high‐frequency RS measurements (typically, from an automated system with hourly sampling) have been made over the last two decades; an increasing number of methane measurements are being made with such systems as well. Such high frequency data are an invaluable resource for understanding GHG fluxes, but lack a central database or repository. Here we describe the lightweight, open‐source COSORE (COntinuous SOil REspiration) database and software, that focuses on automated, continuous and long‐term GHG flux datasets, and is intended to serve as a community resource for earth sciences, climate change syntheses and model evaluation. Contributed datasets are mapped to a single, consistent standard, with metadata on contributors, geographic location, measurement conditions and ancillary data. The design emphasizes the importance of reproducibility, scientific transparency and open access to data. While being oriented towards continuously measured RS, the database design accommodates other soil‐atmosphere measurements (e.g. ecosystem respiration, chamber‐measured net ecosystem exchange, methane fluxes) as well as experimental treatments (heterotrophic only, etc.). We give brief examples of the types of analyses possible using this new community resource and describe its accompanying R software package
Parental provisioning in house wrens: Effects of varying brood size and consequences for offspring
In biparental species, conflict between the sexes is expected when optimal levels of parental care differ between males and females. We studied food provisioning in house wrens (Troglodytes aedon) to test whether male provisioning is more strongly affected than female provisioning by brood size, because this should influence the marginal return on a male\u27s investment. To test this, we created broods of reduced and enlarged size, and found that per-nestling food delivery varied more strongly for males than for females in association with brood size and nestling age; males delivered more food per nestling to enlarged broods, and less to small broods, as nestlings grew and approached asymptotic size. Although parents delivered a greater amount of prey to larger broods, the amount of food per nestling was initially higher for nestlings in small broods, and the amount of food delivered early in nestling development, particularly by males, affected offspring body mass, survival to fledging, and recruitment to the breeding population. However, provisioning rates were negatively associated with prey size, suggesting a trade-off between prey quantity and size. Finally, parents provisioning at a high rate to broods of reduced size were less likely to return to breed, suggesting that they assessed the low return on their investment and dispersed. Although potential for sexual conflict in house wrens remains, our data suggest that its resolution does not involve negotiation over provisioning, possibly because selection for offspring viability favors heavy investment by both parents
Wide-Field Calcium Imaging of Neuronal Network Dynamics In Vivo
A central tenet of neuroscience is that sensory, motor, and cognitive behaviors are generated by the communications and interactions among neurons, distributed within and across anatomically and functionally distinct brain regions. Therefore, to decipher how the brain plans, learns, and executes behaviors requires characterizing neuronal activity at multiple spatial and temporal scales. This includes simultaneously recording neuronal dynamics at the mesoscale level to understand the interactions among brain regions during different behavioral and brain states. Wide-field Ca2+ imaging, which uses single photon excitation and improved genetically encoded Ca2+ indicators, allows for simultaneous recordings of large brain areas and is proving to be a powerful tool to study neuronal activity at the mesoscopic scale in behaving animals. This review details the techniques used for wide-field Ca2+ imaging and the various approaches employed for the analyses of the rich neuronal-behavioral data sets obtained. Also discussed is how wide-field Ca2+ imaging is providing novel insights into both normal and altered neural processing in disease. Finally, we examine the limitations of the approach and new developments in wide-field Ca2+ imaging that are bringing new capabilities to this important technique for investigating large-scale neuronal dynamics
Parental provisioning in house wrens: effects of varying brood size and consequences for offspring
In biparental species, conflict between the sexes is expected when optimal levels of parental care differ between males and females. We studied food provisioning in house wrens (Troglodytes aedon) to test whether male provisioning is more strongly affected than female provisioning by brood size, because this should influence the marginal return on a male\u27s investment. To test this, we created broods of reduced and enlarged size, and found that per-nestling food delivery varied more strongly for males than for females in association with brood size and nestling age; males delivered more food per nestling to enlarged broods, and less to small broods, as nestlings grew and approached asymptotic size. Although parents delivered a greater amount of prey to larger broods, the amount of food per nestling was initially higher for nestlings in small broods, and the amount of food delivered early in nestling development, particularly by males, affected offspring body mass, survival to fledging, and recruitment to the breeding population. However, provisioning rates were negatively associated with prey size, suggesting a trade-off between prey quantity and size. Finally, parents provisioning at a high rate to broods of reduced size were less likely to return to breed, suggesting that they assessed the low return on their investment and dispersed. Although potential for sexual conflict in house wrens remains, our data suggest that its resolution does not involve negotiation over provisioning, possibly because selection for offspring viability favors heavy investment by both parents