6,307 research outputs found
Network properties underlying seed germination control
We sought to gain a mechanistic understanding of the control of seed dormancy and germination by hormone balance. The field has matured to a stage where most of the key genes are known, and competing hypotheses have been proposed to explain how hormone balance works in seeds. During the meeting we simplified a more complex model of seed germination (Figure 1), reducing it to a tractable network. We then showed that if considered as a set of competing protein complexes the network took on the properties of a switch. Results from two models of the reduced network, which incorporated the biological switching phenomena, were found to be in good agreement with both wild and mutant phenotypic data. Our models made the novel prediction that one complex in particular was key to promoting germination, and this prediction can now
be tested in the laboratory
Research Laboratory of Electronics Quarterly status report, 16 Feb. - 15 May 1969
Computer program for calculating large signal nonlinear transient effects in avalanche diod
Research Laboratory of Electronics Semiannual status report, 16 Nov. 1968 - 15 Feb. 1969
Static negative resistance in avalanche diodes and transient
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Assessment, Evaluations and Definitions of Research Impact: A Review
This article aims to explore what is understood by the term âresearch impactâ and to provide a comprehensive assimilation of available literature and information, drawing on global experiences to understand the potential for methods and frameworks of impact assessment being implemented for UK impact assessment. We take a more focused look at the impact component of the UK Research Excellence Framework taking place in 2014 and some of the challenges to evaluating impact and the role that systems might play in the future for capturing the links between research and impact and the requirements we have for these systems.Jisc [DIINN10
Maneuvering for paper: physical and social experiences of bureaucracy in Venezuelan Amazonia
This article explores an apprenticeship in bureaucracy that the Venezuelan Sanema have experienced through their participation in the projects of the late Hugo Chavez's Bolivarian Revolution. The analysis focuses on the maneuverability that paperwork engenders, and thus contributes to an understanding of mobility and corporeal experiences of the state apparatus in contemporary Amazonia. New patterns of movementâtravel to and from cities, daily errands, and maneuvering within social spheresâmust be understood with reference to the state and its bureaucratic pervasiveness, but also as congruous with customary practices of âjourneying for knowledge,â which forge an intimate link between physical and social mobility. The new maneuverability that is both prompted and necessitated by the current political setting is equally as important as literacy in navigating bureaucratic structures and accessing state resources
Dodged Debts and the Submissive Predator:Perspectives on Amazonian Relations of Dependence
This article explores the nature of interethnic asymmetry and the dynamic of long-term dependence in Amazonia. Drawing on the case of the Sanema and their neighbouring Yeâkwana, the article seeks to gain a deeper understanding of submission and indebtedness with a view to re-thinking where the power might lie in such relationships. The association between the two groups, I argue, is motivated by the Sanemaâs pursuit of manufactured items, access to which the Yeâkwana had historically monopolized. The dynamic entered into in order to procure these goods is one of voluntary deference on the part of the Sanema, a demeanour that is actively pursued because it enables morally valued autonomy and a freedom from on-going reciprocity. I conclude that this âsubmissive extractionâ can offer new perspectives on the relationship between debt, predation and freedom
Microbial communities in an anaerobic membrane bioreactor (AnMBR) treating domestic wastewater at ambient temperatures in a temperate climate
Master of ScienceDepartment of Civil EngineeringPrathap ParameswaranThe ever-increasing demand for water, food, and energy and the simultaneous diminishment of our planetsâ ecosystems wrought by humans have prompted a more sustainable approach to engineering the built environment. Wastewater treatment systems stand at the interface that connects the built and natural environment where potential solutions for resource and environmental issues exist. Wastewater treatment technologies can address issues involving water, food, energy, and environmental regulation when resources are properly captured from the wastewater while itâs being treated. This way of thought allows wastewater to be perceived as a source of valuable products rather than an obligate waste stream. For this reason, anaerobic wastewater treatment is progressively being considered because of its ability to improve energy and resource recovery, while reducing costs and environmental impacts associated with conventional domestic wastewater treatment. More specifically, anaerobic membrane bioreactors (AnMBRs) hold promise to effectively treat wastewater at low temperatures with low energy and nutrient requirements, low sludge production, while having the benefit of generating methane-rich biogas suitable as an energy source and the potential to capture nutrients used to fertilize cropland. But, at low temperatures the microbial communities that control anaerobic digestion (AD) face biochemical obstacles. Elucidating the microbial community dynamics within AnMBRs with respect to seasonal temperatures will give insight on how to efficiently operate AnMBRs with the goal of energy-neutral wastewater treatment. DNA based tools such as advanced high-throughput sequencing was coupled with AnMBR process data to explicate the mechanism of methane production in the suspended biomass of an AnMBR from a mesophilic startup leading into psychrophilic conditions, and then returning to mesophilic temperatures
Golden-winged warbler (\u3cem\u3eVermivora chrysoptera\u3c/em\u3e) demographics and habitat use and the potential effects of land use change on golden-winged and cerulean warblers (\u3cem\u3eDendroica cerulea\u3c/em\u3e) in the Cumberland Mountains of Tennessee
The golden-winged warbler (Vermivora chrysoptera) is an early successional Nearctic-Neotropical migrant songbird undergoing population declines range-wide. The Cumberland Mountains contain one of the southernmost populations where goldenwingeds occur in relatively high densities on old reclaimed surface mines. The three objectives of this research were to (1) describe the basic demography and habitat use of this population, (2) compare the demography of the Cumberland population to a population in Ontario, and (3) to model alternative land use scenarios and the impacts on both the golden-winged warbler and the cerulean warbler (Dendroica cerulean), another declining Nearctic-Neotropical migrant that occupies mature forests. Specifically, I modeled daily nest survival rate as a function of biologically meaningful covariates (Part 2) and the relative effects of habitat and demographic factors on territory size variation (Part 3) for the Tennessee population. There was some evidence of annual variation in nest survival rates and a decline throughout the nesting season, but I found little evidence that local habitat characteristics measurably affected nest survival. Territory size varied with the percent cover of vines and the number of snags. The single demographic factor related to territory size was nest success; birds with larger territories had a greater rate of nest success. I compared annual adult survival, fecundity, rate of population growth (λ), and mean time to extinction for Tennessee and Ontario populations (Part 4). Adult survival and fecundity were similar for the two populations such that predictions based on the theory of life history variation with latitude were not supported. Lambda estimates suggested that both populations were declining and I projected extirpation within 20-30 years without immigration. To further explore avian populations in the Cumberlands, I modeled coal mining, reclamation, and timber harvesting under a base-case scenario (as described by landowners and industries) as well as for alternatives that limited the amount of disturbance (Part 5). None of the scenarios were sustainable alternatives for cerulean and golden-winged warbler populations. My results suggest that future disturbances should be significantly limited to meet cerulean population goals and existing early successional habitat should be maintained and enhanced to sustain goldenwinged warbler populations
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