Electrochemical carbon dioxide concentrator subsystem development

The most promising concept for a regenerative CO2 removal system for long duration manned space flight is the Electrochemical CO2 Concentrator (EDC), which allows for the continuous, efficient removal of CO2 from the spacecraft cabin. This study addresses the advancement of the EDC system by generating subsystem and ancillary component reliability data through extensive endurance testing and developing related hardware components such as electrochemical module lightweight end plates, electrochemical module improved isolation valves, an improved air/liquid heat exchanger and a triple redundant relative humidity sensor. Efforts included fabrication and testing the EDC with a Sabatier CO2 Reduction Reactor and generation of data necessary for integration of the EDC into a space station air revitalization system. The results verified the high level of performance, reliability and durability of the EDC subsystem and ancillary hardware, verified the high efficiency of the Sabatier CO2 Reduction Reactor, and increased the overall EDC technology engineering data base. The study concluded that the EDC system is approaching the hardware maturity levels required for space station deployment

Comparative Recruitment Dynamics of Alewife and Bloater in Lakes Michigan and Huron

The predictive power of recruitment models often relies on the identification and quantification of external variables, in addition to stock size. In theory, the identification of climatic, biotic, or demographic influences on reproductive success assists fisheries management by identifying factors that have a direct and reproducible influence on the population dynamics of a target species. More often, models are constructed as one‐time studies of a single population whose results are not revisited when further data become available. Here, we present results from stock recruitment models for Alewife Alosa pseudoharengus and Bloater Coregonus hoyi in Lakes Michigan and Huron. The factors that explain variation in Bloater recruitment were remarkably consistent across populations and with previous studies that found Bloater recruitment to be linked to population demographic patterns in Lake Michigan. Conversely, our models were poor predictors of Alewife recruitment in Lake Huron but did show some agreement with previously published models from Lake Michigan. Overall, our results suggest that external predictors of fish recruitment are difficult to discern using traditional fisheries models, and reproducing the results from previous studies may be difficult particularly at low population sizes.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141414/1/tafs0294.pd

Plans for Crash-Tested Bridge Railings for Longitudinal Wood Decks on Low-Volume Roads

The plans for crashworthy bridge railings for low-volume roads were developed through a cooperative research program involving the USDA Forest Service, Forest Products Laboratory (FPL); the Midwest Roadside Safety Facility, University of Nebraska-Lincoln (MwRSF); and the Forest Service, National Forest System, Engineering. Three railings were developed and successfully tested in accordance with National Cooperative Highway Research Program (NCHRP) Report 350 Test Level-1 requirements. The fourth system was developed for a lower test level based on criteria developed by the Forest Service for single-lane bridges on very low-volume roads. For the convenience of the user, full drawing sets are provided in customary U.S. and S.I. units

Testing for Evidence of Maternal Effects among Individuals and Populations of White Crappie

For an increasing number of species, maternal characteristics have been correlated with the characteristics of their eggs or larvae at the individual level. Documenting these maternal effects at the population level, however, is uncommon. For white crappies Pomoxis annularis, we evaluated whether individual maternal effects on eggs existed and then explored whether incorporating maternal effects explained additional variation in recruitment, a population-level response. Individual egg quality (measured as ovary energy density) increased with maternal length among individuals from seven Ohio reservoirs in 1999 and three in 2000. Among these same individuals, egg quality increased with maternal condition factor (measured as residual wet mass for a given length) in 1999 but not in 2000. In 2000 we estimated somatic energy density, an improved measure of condition; egg quality increased with somatic energy density, but somatic energy density was also strongly correlated with maternal length. Hence, we could not determine whether maternal length or condition was the primary factor influencing white crappie egg quality. Across seven populations, the relative population fecundity (i.e., stock size) of the 1999 year-class was unable to explain the variation in recruitment to age 2 (Ricker model r^2 = 0.04 and Beverton and Holt model r^2 = 0.02). Mean ovary energy density (i.e., egg quality), however, was unable to explain additional recruitment variability in either model. Hence, we documented evidence of maternal effects on individual ovaries but not on population-level recruitment. Nonetheless, we recommend that future studies seeking to understand white crappie recruitment continue to consider maternal effects as a potential factor, especially those studies that may have greater sample sizes at the population level and, in turn, a greater probability of documenting a population-level effect.This research was funded by Federal Aid in Sport Fish Restoration Project F-69-P, administered jointly by U.S. Fish and Wildlife Service and Ohio Department of Natural Resources, Division of Wildlife and the Department of Evolution, Ecology, and Organismal Biology at Ohio State University

Climate-influenced phenology of larval fish transport in a large lake

Elucidating physical transport phenologies in large lakes can aid understanding of larval recruitment dynamics. Here, we integrate a series of climate, hydrodynamic, biogeochemical, and Lagrangian particle dispersion models to: (1) simulate hatch and transport of fish larvae throughout an illustrative large lake, (2) evaluate patterns of historic and potential future climate-induced larval transport, and (3) consider consequences for overlap with suitable temperatures and prey. Simulations demonstrate that relative offshore transport increases seasonally, with shifts toward offshore transport occurring earlier during relatively warm historic and future simulations. Intra- and inter-annual trends in transport were robust to assumed pelagic larval duration and precise location and timing of hatching. Larvae retained nearshore generally encountered more favorable temperatures and zooplankton densities compared to larvae transported offshore. Larval exploitation of nearshore resources under climate change may depend on a concomitant shift to earlier spawning and hatch times in advance of earlier offshore transport

Evaluating consumptive and nonconsumptive predator effects on prey density using field time‐series data

Determining the degree to which predation affects prey abundance in natural communities constitutes a key goal of ecological research. Predators can affect prey through both consumptive effects (CEs) and nonconsumptive effects (NCEs), although the contributions of each mechanism to the density of prey populations remain largely hypothetical in most systems. Common statistical methods applied to time‐series data cannot elucidate the mechanisms responsible for hypothesized predator effects on prey density (e.g., differentiate CEs from NCEs), nor can they provide parameters for predictive models. State‐space models (SSMs) applied to time‐series data offer a way to meet these goals. Here, we employ SSMs to assess effects of an invasive predatory zooplankter, Bythotrephes longimanus, on an important prey species, Daphnia mendotae, in Lake Michigan. We fit mechanistic models in an SSM framework to seasonal time series (1994–2012) using a recently developed, maximum‐likelihood–based optimization method, iterated filtering, which can overcome challenges in ecological data (e.g., nonlinearities, measurement error, and irregular sampling intervals). Our results indicate that B. longimanus strongly influences D. mendotae dynamics, with mean annual peak densities of B. longimanus observed in Lake Michigan estimated to cause a 61% reduction in D. mendotae population growth rate and a 59% reduction in peak biomass density. Further, the observed B. longimanus effect is most consistent with an NCE via reduced birth rates. The SSM approach also provided estimates for key biological parameters (e.g., demographic rates) and the contribution of dynamic stochasticity and measurement error. Our study therefore provides evidence derived directly from survey data that the invasive zooplankter B. longimanus is affecting zooplankton demographics and offer parameter estimates needed to inform predictive models that explore the effect of B. longimanus under different scenarios, such as climate change.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148243/1/ecy2583-sup-0001-AppendixS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148243/2/ecy2583_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148243/3/ecy2583.pd

17 ways to say yes:Toward nuanced tone of voice in AAC and speech technology

People with complex communication needs who use speech-generating devices have very little expressive control over their tone of voice. Despite its importance in human interaction, the issue of tone of voice remains all but absent from AAC research and development however. In this paper, we describe three interdisciplinary projects, past, present and future: The critical design collection Six Speaking Chairs has provoked deeper discussion and inspired a social model of tone of voice; the speculative concept Speech Hedge illustrates challenges and opportunities in designing more expressive user interfaces; the pilot project Tonetable could enable participatory research and seed a research network around tone of voice. We speculate that more radical interactions might expand frontiers of AAC and disrupt speech technology as a whole

Preliminary assessment of candidate immobilization technologies for retrieved single-shell tank wastes

This report describes the initial work that has been performed to select technologies for immobilization of wastes that may be retrieved from Hanford single-shell tanks (SSTs). Two classes of waste will require immobilization. One is the combined high-level waste/transuranic (HLW/TRU) fraction, the other the low-level waste (LLW) fraction. A number of potential immobilization technologies are identified for each class of waste. Immobilization technologies were initially selected based on a number of considerations, including (1) the waste loading that could likely be achieved within the constraint of producing acceptable waste forms, (2) process flexibility (primarily compatibility with anticipated waste variability), (3) process complexity, and (4) state of development. Immobilization technologies selected for further development include the following: for HLW/TRU waste -- borosilicate glass, lead-iron phosphate glass, glass-calcine composites, glass-ceramics, and cement based forms; for non-denitrated LLW -- grout, laxtex-modified concrete, and polyethylene; and for denitrated LLW -- silicate glass, phosphate glass, and clay calcination or tailored ceramic in various matrices

'Once there is life, there is hope' Ebola survivors' experiences, behaviours and attitudes in Sierra Leone, 2015.

BACKGROUND: In Sierra Leone, over 4000 individuals survived Ebola since the outbreak began in 2014. Because Ebola survivorship was largely unprecedented prior to this outbreak, little is known about survivor experiences during and post illness. METHODS: To assess survivors' experiences and attitudes related to Ebola, 28 in-depth interviews and short quantitative surveys with survivors from all four geographic regions of Sierra Leone were conducted in May 2015. RESULTS: Survivor experiences, emotions and attitudes changed over time as they moved from disease onset to treatment, discharge and life post-discharge. Survivors mentioned experiencing acute fear and depression when they fell ill. Only half reported positive experiences in holding centres but nearly all were positive about their treatment centre experiences. Survivor euphoria on discharge was followed by concerns about their financial situation and future. While all reported supportive attitudes from family members, about a third described discrimination and stigma from their communities. Over a third became unemployed, especially those previously engaged in petty trade. Survivor knowledge about sexual transmission risk reflected counselling messages. Many expressed altruistic motivations for abstinence or condom use. In addition, survivors were strongly motivated to help end Ebola and to improve the healthcare system. Key recommendations from survivors included improved counselling in holding centres and long-term government support for survivors, including opportunities for participation in Ebola response efforts. CONCLUSIONS: Survivors face myriad economic, social and health challenges. Addressing survivor concerns, including the discrimination they face, could facilitate their reintegration into communities and their contributions to future Ebola responses

A Model for the Interplay of Receptor Recycling and Receptor-Mediated Contact in T Cells

Orientation of organelles inside T cells (TC) toward antigen-presenting cells (APC) ensures that the immune response is properly directed, but the orientation mechanisms remain largely unknown. Structural dynamics of TC are coupled to dynamics of T-cell receptor (TCR), which recognizes antigen on the APC surface. Engagement of the TCR triggers its internalization followed by delayed polarized recycling to the plasma membrane through the submembrane recycling compartment (RC), which organelle shares intracellular location with the TC effector apparatus. TCR engagement also triggers TC-APC interface expansion enabling further receptor engagement. To analyze the interplay of the cell-cell contact and receptor dynamics, we constructed a new numerical model. The new model displays the experimentally observed selective stabilization of the contact initiated next to the RC, and only transient formation of contact diametrically opposed to the RC. In the general case wherein the TC-APC contact is initiated in an arbitrary orientation to the RC, the modeling predicts that the contact dynamics and receptor recycling can interact, resulting effectively in migration of the contact to the TC surface domain adjacent to the submembrane RC. Using three-dimensional live-cell confocal microscopy, we obtain data consistent with this unexpected behavior. We conclude that a TC can stabilize its contact with an APC by aligning it with the polarized intracellular traffic of TCR. The results also suggest that the orientation of TC organelles, such as the RC and the effector apparatus, toward the APC can be achieved without any intracellular translocation of the organelles