Analysis of ground source heat pumps in sub-Arctic conditions

Master's Project (M.S.) University of Alaska Fairbanks, 2014The Purpose of this project is to investigate the factors involved in the application of a ground source heat pump in subarctic conditions. This project originated with the construction of a ground source heat pump (GSHP) built at Cold Climate Housing Research Center's (CCHRC) Research Testing Facility. The GSHP built by CCHRC is an experiment to test the viability of a GSHP with different surface coverings. Specifically, this project will focus on different soil and atmospheric properties to gauge their effect on a GSHP in sub-arctic conditions. The project is primarily broken into 3 main sections which test in simulation: the effects of soil and atmospheric properties on heat flow into soil, the effects of these properties on a hypothetical GSHP and applying this to a simulation of CCHRC's GSHP. Additionally, some mitigation efforts were attem pted in simulation to improve the viability of the GSHP built by CCHRC

A consideration of resistance and tolerance for ruminant nematode infections

Debates on the relative merits of resistance (the ability of the host to control the parasite lifecycle) and tolerance (the net impact of infection on host performance) are often lively and unhindered by data or evidence. Resistance generally shows continuous, heritable variation but data are sparser for tolerance, the utility of which will depend upon the disease prevalence. Prevalence is a function of group mean resistance and infection pressure, which itself is influenced by mean resistance. Tolerance will have most value for endemic diseases with a high prevalence, but will be of little value for low prevalence diseases. The conditionality of tolerance on infection status, and hence resistance, makes it difficult to estimate independently of resistance.Tolerance is potentially tractable for nematode infections, as the prevalence of infection is ca. 100% in animals grazing infected pasture, and infection level can be quantified by faecal egg count (FEC). Whilst individual animal phenotypes for tolerance are difficult to estimate, breeding values are estimable if related animals graze pastures of different contamination levels. Selection for resistance, i.e. FEC, provides both direct and indirect benefits from ever decreased pasture contamination and hence decreased infectious challenge. Modelling and experimental studies have shown that such reductions in pasture contamination may lead to substantially increased performance.It is proposed that selection goals addressing nematode infections should include both resistance and performance under challenging conditions. However, there may be benefits from exploiting large datasets in which sires are used across cohorts differing in infection level, to further explore tolerance. This may help to customise breeding objectives, with tolerance given greater weight in heavily parasitized environments

The Case Against Copyright Protection for Programmable Logic Devices

Several commentators have argued that copyright protection should extend to protect logic equations incorporated in a type of semiconductor chip called a programmable logic device (PLD). They reach this result by analogizing to the storage of computer software in memory chips, an embodiment that is currently protected under the copyright laws. This Comment analyzes logic equations incorporated in a PLD with respect to the copyright statute, utilitarian device doctrine, and the legislative history of the Semiconductor Chip Protection Act. It concludes that copyright protection should not extend to protect the logic equations incorporated in a PLD

Genetic management strategies for controlling infectious diseases in livestock populations

This paper considers the use of disease resistance genes to control the transmission of infection through an animal population. Transmission is summarised by R0, the basic reproductive ratio of a pathogen. If R0 > 1.0 a major epidemic can occur, thus a disease control strategy should aim to reduce R0 below 1.0, e.g. by mixing resistant with susceptible wild-type animals. Suppose there is a resistance allele, such that transmission of infection through a population homozygous for this allele will be R02 < R01, where R01 describes transmission in the wildtype population. For an otherwise homogeneous population comprising animals of these two groups, R0 is the weighted average of the two sub-populations: R0 = R01ρ + R02 (1 - ρ), where ρ is the proportion of wildtype animals. If R01 > 1 and R02 < 1, the proportions of the two genotypes should be such that R0 ≤ 1, i.e. ρ ≤ (R0 - R02)/(R01 - R02). If R02 = 0, the proportion of resistant animals must be at least 1 - 1/R01. For an n genotype model the requirement is still to have R0 ≤ 1.0. Probabilities of epidemics in genetically mixed populations conditional upon the presence of a single infected animal were derived. The probability of no epidemic is always 1/(R0 + 1). When R0 ≤ 1 the probability of a minor epidemic, which dies out without intervention, is R0/(R0 + 1). When R0 > 1 the probability of a minor and major epidemics are 1/(R0 + 1) and (R0 - 1)/(R0 + 1). Wherever possible a combination of genotypes should be used to minimise the invasion possibilities of pathogens that have mutated to overcome the effects of specific resistance alleles

Recovery in Level 7-10 USA Artistic Gymnastics

International Journal of Exercise Science 10(5): 734-742, 2017. This study assessed physical performance in women’s artistic gymnastics following three variable recovery periods. Participants included fifteen female gymnasts (mean age = 13.5 ± 1.1) who had competed at USA Gymnastics (USAG) levels 7 – 10 within at least one year prior to the study. Each testing session consisted of a warm-up followed by four muscular endurance tests and one explosive maximal test. Assessments included pull-ups, leg lifts, handstand push-ups, vertical jump, and push-ups. After the performance assessments, the participants completed a typical practice session. The performance measures were reassessed at the beginning of each of the recovery periods of 24, 48, and 72 hours in a counterbalanced design. Performance assessments were converted into Z-scores and then averaged for a composite session Z-score. The composite session Z-scores were compared to evaluate the recovery duration. Composite Z’s were significantly lower (p=0.000), after the 24 (z=-1.10) and the 48 hour (z=-0.71) recovery periods compared to baseline (z=0.00). However, there was no difference in scores (p=1.00) between the baseline and 72 hours (z=0.004) recovery. Full recovery required 72 hours under the conditions of this study

A genetic epidemiological model to describe resistance to an endemic bacterial disease in livestock: application to footrot in sheep

Selection for resistance to an infectious disease not only improves resistance of animals, but also has the potential to reduce the pathogen challenge to contemporaries, especially when the population under selection is the main reservoir of pathogens. A model was developed to describe the epidemiological cycle that animals in affected populations typically go through; viz. susceptible, latently infected, diseased and infectious, recovered and reverting back to susceptible through loss of immunity, and the rates at which animals move from one state to the next, along with effects on the pathogen population. The equilibrium prevalence was estimated as a function of these rates. The likely response to selection for increased resistance was predicted using a quantitative genetic threshold model and also by using epidemiological models with and without reduced pathogen burden. Models were standardised to achieve the same genetic response to one round of selection. The model was then applied to footrot in sheep. The only epidemiological parameters with major impacts for prediction of genetic progress were the rate at which animals recover from infection and the notional reproductive rate of the pathogen. There are few published estimates for these parameters, but plausible values for the rate of recovery would result in a response to selection, in terms of changes in the observed prevalence, double that predicted by purely genetic models in the medium term (e.g. 2–5 generations)

Progress and limits of PrP gene selection policy

Classical scrapie has proved to be a notoriously difficult disease to control due to a poor understanding of its natural history. The recognition of disease risk linkage to PrP genotype has offered the prospect of a disease control strategy, viz. genotyping and selective breeding, novel to veterinary medicine when first considered in the 1990s. The UK Spongiform Encephalopathy Advisory Committee recommended the exploitation of this approach in a voluntary, national programme to control classical scrapie and protect the public against food-borne exposure to bovine spongiform encephalopathy, should the national flock have been exposed via contaminated feed. The National Scrapie Plan for Great Britain was launched in 2001 and uptake has been widespread throughout the purebreeding sector of the sheep industry, with membership peaking at over 12 000 flocks in 2006. A total of 700 000 rams from 90 breeds have been genotyped. A comparison of ram lambs born in 2002 with those in 2006 shows evident changes in PrP genotype frequencies which are predicted to be associated with a reduction in disease risk. Various concerns have been raised regarding possible unintended consequences of widespread selection on PrP genotype, including impacts on other performance traits and possible effects on inbreeding and genetic diversity. To date, these concerns appear to be unfounded, as no consistent associations have been found with performance traits, nor are there likely to be any detectable impacts on inbreeding in mainstream breeds. Currently, semen banks have been implemented in Great Britain to store samples from animals of all common PrP genotypes, should these genotypes be required in the future. Various strategies to minimise future disease risks are discussed in the paper

A substantial eastern disjunction of Douglas’ Knotweed (Polygonum douglasii Greene, Polygonaceae) in New Brunswick, Canada

We report an isolated population of the native annual Douglas’ Knotweed (Polygonum douglasii Greene) from a dry, south-facing outcrop of conglomerate and sandstone at Big Bluff, near Sussex Corner, New Brunswick, Canada, consisting of about 2500 plants in 2018 and 2022. This occurrence is disjunct by ~450 km from the eastern limit of the known range of Douglas’ Knotweed in southwestern Maine, USA. The nearest known occurrence in Canada is in southern Quebec, ~660 km from Big Bluff. Several lines of evidence indicate that the population in New Brunswick is native. New state records for Wisconsin and Alaska found in online data sources are also verified