Christy Tyler

This project contains data obtained by a consumer survey on preferences regarding product adoption, use, functionality, and replacement. <br>The Internet-based survey was developed by the authors with the support of Meliora Research, LLC, a market research and survey design firm, and administered in February 2015. The survey was administered to a panel of United States adults that was recruited and maintained by Lightspeed GMI, using their sampling and panel management platform. <br>The survey protocol and informed consent process was reviewed and approved by the Rochester Institute of Technology Institutional Review Board. The respondents' identities remained confidential, and researchers had no contact with the respondents. The panel was designed to be a nationally representative population, and survey results are comprised of responses from 1,011 US adults, aged 18 years and older. This sample size, relative to the total population of U.S. adults, provided a margi...

Background/Question/Methods Increases in the frequency and severity of disturbance events, such as periodic hypoxia and sediment resuspension by trawling, have lead to dramatic changes in benthic invertebrate communities in many coastal regions. In order to predict the effects of disturbance on ecosystem function, it is necessary to improve our understanding of how changes in invertebrate density and diversity affect benthic geochemical cycling. We used laboratory microcosms to test the effects of recolonization of previously defaunated sediments by deep-burrowing polychaetes (Nereis virens) and suspension-feeding bivalves (Mya arenaria) on porewater ammonium and soluble-sulfide concentrations as well as benthic fluxes of oxygen and nutrients: dissolved inorganic nitrogen (ammonium and nitrate + nitrite, or DIN) and soluble reactive phosphorus (SRP). We added single and two-species treatments including a range of densities comparable to densities common for shallow estuaries. We sam...

Background/Question/Methods Plant introductions in estuarine systems can produce substantial changes ranging from species replacement to broad-scale alteration of ecosystem properties. Here we examine the changes produced by the invasion of Atlantic smooth cordgrass Spartina alterniflora in two Pacific estuaries, San Francisco Bay, CA and Willapa Bay, WA. We compare and contrast benthic invertebrate foodwebs inhabiting invasive Spartina meadows relative to naturally unvegetated muflats (SF Bay) or relative to mudflats colonized by introduced Zostera japonica (Willapa Bay). In both bays, we use dual isotopic tracer experiments with δ 15N labeled Spartina detritus and δ 13C labeled microalgae as well as δ 15N labeled Zostera japonica detritus in Willapa Bay. Results/Conclusions At both sites, our results showed similar and substantial shifts in benthic communities including reductions in larger, surface-feeding taxa concurrent with increases in smaller, subsurface detritivores with po...

Plastic responses to stress in components of reproduction can have important effects on plant fitness and can vary both within and between species. Responses may also depend on when in the life cycle stress occurs. Here, it is predicted that the timing of initiation of a stress, defoliation, would affect the pattern of plastic responses. These differences should occur because some components of reproduction, such as flower number, are determined earlier in a plant's life than others, such as individual seed mass. To test this prediction, 50 % artificial defoliation treatments were initiated at four different times for Sesbania macrocarpa and S. vesicaria. Responses were measured in plant size, number of flowers, number of flowers/plant size, fruit set, number of seeds per fruit, individual seed mass and total seed mass per plant. For S. vesicaria, changes in the timing of stress changed the severity, but not the pattern of response. For S. macrocarpa, plastic responses to defoli...

Abstract Epistasis, or gene-gene interaction, is a ubiquitous phenomenon that is inadequately addressed in human genetic studies. There are few tools that can accurately identify high-order epistatic interactions, and there is a lack of general understanding as to how epistatic interactions fit into genetic architecture. Here we approach both problems through the lens of genetic programming (GP). It has recently been proposed that increasing open-endedness of GP will result in more complex solutions that better acknowledge the ...

Hippocampal theta rhythm is believed to play a critical role in learning and memory. In animal models of temporal lobe epilepsy (TLE), there is evidence that alterations of hippocampal theta oscillations are involved in the cognitive impairments observed in this model. However, hippocampal theta frequency and amplitude at both the local field potential (LFP) and single unit level are strongly modulated by running speed, suggesting that the integration of locomotor information into memory processes may also be critical for hippocampal processing. Here, we investigate whether hippocampal speed-theta integration influences spatial memory and whether it could account for the memory deficits observed in TLE rats. LFPs were recorded in both Control (CTR) and TLE rats as they were trained in a spatial alternation task. TLE rats required more training sessions to perform the task at CTR levels. Both theta frequency and power were significantly lower in the TLE group. In addition, speed/theta frequency correlation coefficients and regression slopes varied from session to session and were worse in TLE. Importantly, there was a strong relationship between speed/theta frequency parameters and performance. Our analyses reveal that speed/theta frequency correlation with performance cannot merely be explained by the direct influence of speed on behavior. Therefore, variations in the coordination of theta frequency with speed may participate in learning and memory processes. Impairments of this function could explain at least partially memory deficits in epilepsy.

ABSTRACT A mechanistic understanding of population dynamics requires close examination of species' differences in how physiological traits interact with environmental variation and translate into demographic variation. We focused on two co-occurring winter annual species (Pectocarya recurvata and Plantago insularis) that differ in photosynthetic resource-use efficiency and demographic responses to environmental variation and covariation between temperature and water availability. Previous work showed that Pectocarya has higher water-use efficiency and nitrogen allocation to light-driven dynamics of the Calvin cycle (Jmax:VCmaxVCmax) than Plantago, which is often associated with enhanced electron transport capacity at low temperatures and better light harvesting capacity. These traits could enhance Pectocarya photosynthesis during reliably moist but cool, cloudy periods following precipitation. We acclimated plants to low and high temperatures and then measured gas exchange across a 30 °C temperature range. As predicted, optimal temperatures of photosynthesis were lower for Pectocarya than Plantago. Additionally, Pectocarya experienced greater respiratory carbon loss than Plantago at higher temperatures (every 1 °C increase beyond 24 °C increased the ratio of carbon loss to gain 9% and 27% in cold and warm-acclimated plants, respectively). These differential patterns of photosynthetic optimization and assimilation in response to differing rainfall distributions may have important implications for population dynamic differences and species coexistence.