5,297 research outputs found
A Biologically Informed Hylomorphism
Although contemporary metaphysics has recently undergone a neo-Aristotelian revival wherein dispositions, or capacities are now commonplace in empirically grounded ontologies, being routinely utilised in theories of causality and modality, a central Aristotelian concept has yet to be given serious attention – the doctrine of hylomorphism. The reason for this is clear: while the Aristotelian ontological distinction between actuality and potentiality has proven to be a fruitful conceptual framework with which to model the operation of the natural world, the distinction between form and matter has yet to similarly earn its keep. In this chapter, I offer a first step toward showing that the hylomorphic framework is up to that task. To do so, I return to the birthplace of that doctrine - the biological realm. Utilising recent advances in developmental biology, I argue that the hylomorphic framework is an empirically adequate and conceptually rich explanatory schema with which to model the nature of organism
Reducing Uncertainties in the Production of the Gamma Emitting Nuclei 26Al, 44Ti, and 60Fe in Core Collapse Supernovae by Using Effective Helium Burning Rates
We have used effective reaction rates (ERR) for the helium burning reactions
to predict the yield of the gamma-emitting nuclei 26Al, 44Ti, and 60Fe in core
col- lapse supernovae. The variations in the predicted yields for values of the
reaction rates allowed by the ERR are much smaller than obtained previously,
and smaller than other uncertainties. A "filter" for supernova nucleosynthesis
yields based on pre-supernova structure was used to estimate the effect of
failed supernovae on the initial mass function-averaged yields; this
substantially reduced the yields of all these isotopes, but the predicted yield
ratio 60Fe/26Al was little affected. The robustness of this ratio is promising
for comparison with data, but it is larger than observed in nature; possible
causes for this discrepancy are discussed.Comment: 16 pages, 3 figure
Assessing Occupational Exposure Risk and COVID-19 Incidence Rates in Nebraska by Industry and Occupation, 2020
Occupational outbreaks of COVID-19 have been described during the pandemic, yet the epidemiology of COVID-19 across a larger workforce population is currently not well characterized in the United States. Describing COVID-19 incident rates by industry and occupation will elucidate how the pandemic affected the workforce in Nebraska. However, nonresponse bias occurs in the employment information when participants are unwilling or unable to respond to contract tracer questions, thus affecting the results. Nonresponse bias will be analyzed, and appropriate statistical approaches will be utilized to adjust for any bias in the data. Adjusting for bias, incidence rates by detailed industry and occupation groups will be calculated using employment data from American Community Survey Public Use Microdata Sample data. Comparison of occupational incidence rates to the Council of State and Territorial Epidemiologists SARS-CoV-2 Occupational Exposure Matrix highlights its potential use to identify occupations with high, medium, and low exposure risks. By describing how Nebraska’s workforce was affected by the COVID-19 pandemic, and identifying what occupations are at higher risk for COVID-19 exposures, we can better to develop improved prevention strategies
Source Rock Overpressure Prediction and Its Relation to Kerogen Maturity
Accurate formation pressure estimation is important to drilling and production operations and necessary for reservoir engineering calculations. Methods developed to estimate formation pressure from well logs are reliable for conventional reservoirs but do not translate well to unconventionals. Due to a limited hydraulic connectivity between the organic matter (kerogen) pore network and the inorganic matrix pore network holding the stored hydrocarbons, current methods may not accurately estimate the magnitude of overpressure in source rocks and unconventional targets in mature basins.
In this work, a pressure estimation method is developed mainly using data from porosity logs. The proposed method is applied to areas in the Delaware Basin to demonstrate the presence of overpressure in the Bone Spring Sands and Wolfcamp formation. Validation pressure measurements based on DST, flowback, and managed pressure drilling data through multiple horizons indicate the weak transport coupling of the 3rd Bone Spring Sands and Wolfcamp horizons while also demonstrating a reliable method to estimate formation pressures using sonic well logs. The estimated overpressures in the Delaware Basin demonstrate a strong correlation with previously measured kerogen maturity and indicate that hydrocarbon generation is the significant source of the recognized present day overpressure
Evaluating the effects of pine and miscanthus biochar on water activity and Escherichia coli populations in commercial broiler litter
The decrease in subtherapeutic antibiotic administration in poultry has increased the need to address production challenges caused by pathogens, such as E. coli. One potential way to improve bird health and reduce bacterial infection is through the addition of litter amendments that absorb moisture. Biochar (BC) has previously been shown to increase water holding capacity in poultry litter, but its effects on E. coli mitigation are unknown. The objectives of this research were to 1) evaluate water activity of poultry litter amended with pine and miscanthus BC, and 2) determine the effects of different BC inclusion rates on litter E. coli populations. The studies found that BC increased water activity when mixed with broiler litter, and pine BC resulted in lower E. coli counts over time than miscanthus BC. An inclusion rate of 30% by weight of pine BC was most effective at reducing E. coli populations in broiler litter
HaskHOL: A Haskell Hosted Domain Specific Language for Higher-Order Logic Theorem Proving
HaskHOL is an implementation of a HOL theorem proving capability in Haskell. Motivated by a need to integrate theorem proving capabilities into a Haskell-based tool suite, HaskHOL began as a simple port of HOL Light to Haskell. However, Haskell's laziness, immutable data, and monadic extensions both complicate an implementation and enable a new feature class. This thesis describes HaskHOL, its motivation and implementation. Its use to implement a primitive, interactive theorem prover is explored and its performance is evaluated using a collection of intuitionistically valid problems
Thermal adaptation of life history traits in the Drosophila melanogaster group
Thermal adaptation is typically detected by examining the tolerance to extreme temperatures in a few populations within a single life stage. However, the extent to which adaptation occurs among many different populations might depend on the tolerance of multiple life stages and the average temperature range that the population experiences. Here, I examined adaptation to local temperature conditions in four species of fruit flies, including a cosmopolitan species, Drosophila melanogaster, and three species with geographically small-sized ranges, D. nepalensis, D. sechellia, and D. mauritiana. The cosmopolitan species showed adaptation to native temperatures during the larval and adult life stages, but the species with geographically restricted ranges differed in their responses to temperature changes during all life stages. Therefore, species with restricted ranges are more sensitive to temperature shifts than widespread species, and within species there are differences in tolerance among populations and life stages
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