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Item Nicotine exacerbates exertional heat strain in trained men: A randomized, placebo-controlled, double-blind study.(American Physiological Society, 2024-08-16) Moyen NE; Barnes MJ; Perry BG; Fujii N; Amano T; Kondo N; Mundel TTo determine whether using nicotine exacerbates exertional heat strain through an increased metabolic heat production (Hprod) or decreased skin blood flow (SkBF), 10 nicotine-naïve trained males [37 ± 12 yr; peak oxygen consumption (V̇o2peak): 66 ± 10 mL·min−1·kg−1] completed four trials at 20°C and 30°C following overnight transdermal nicotine (7 mg·24 h−1) and placebo use in a crossover, double-blind design. They cycled for 60 min (55% V̇o2peak) followed by a time trial (∼75% V̇o2peak) during which measures of gastrointestinal (Tgi) and mean weighted skin (̅Tsk) temperatures, SkBF, Hprod, and mean arterial pressure (MAP) were made. The difference in ΔTgi between nicotine and placebo trials was greater during 30°C (0.4 ± 0.5°C) than 20°C (0.1 ± 0.7°C), with ̅Tsk higher during nicotine than placebo trials (0.5 ± 0.5°C, P = 0.02). SkBF became progressively lower during nicotine than placebo trials (P = 0.01) and progressively higher during 30°C than 20°C trials (P < 0.01); MAP increased from baseline (P < 0.01) and remained elevated in all trials. The difference in Hprod between 30°C and 20°C trials was lower during nicotine than placebo (P = 0.01) and became progressively higher during 30°C than 20°C trials with exercise duration (P = 0.03). Mean power output during the time trial was lower during 30°C than 20°C trials (24 ± 25 W, P = 0.02), and although no effect of nicotine was observed (P > 0.59), two participants (20%) were unable to complete their 30°C nicotine trials as one reached the ethical limit for Tgi (40.0°C), whereas the other withdrew due to “nausea and chills” (Tgi = 39.7°C). These results demonstrate that nicotine use increases thermal strain and risk of exertional heat exhaustion by reducing SkBF. NEW & NOTEWORTHY In naïve participants, acute nicotine use exerts a hyperthermic effect that increases the risk of heat exhaustion during exertional heat strain, which is driven by a blunted skin blood flow response. This has implications for 1) populations that face exertional heat strain and demonstrate high nicotine use (e.g., athletes and military, 25%–50%) and 2) study design whereby screening and exclusion for nicotine use or standardization of prior use (e.g., overnight abstinence) is encouraged.Item Amplification of Ovis aries papillomavirus type 2 DNA from an ovine cutaneous fibropapilloma.(John Wiley and Sons, Inc., 2024-04-01) Munday JS; Klobukowska HJ; Nicholson KSeven of 60 Perendale sheep within a flock developed single or multiple exophytic masses on their distal hind limbs. A mass was excised from one sheep and histological evaluation revealed epidermal and mesenchymal proliferation, papillomavirus-induced keratinocyte changes and marked keratohyalin clumping. Ovis aries papillomavirus type 2 DNA sequences were amplified using PCR.Item Osteoinductive squamous cell carcinoma associated with a putative novel papillomavirus on the digit of a cat.(Taylor and Francis Group, 2024-03-01) Munday JS; Dunbar ME; Wightman P; Piripi SCASE HISTORY AND CLINICAL FINDINGS: An approximately 10-year-old, castrated male domestic short-haired cat developed swelling and ulceration of the second digit of the right front paw. Radiographs revealed a spherical soft tissue swelling with irregular distal margins that contained multiple lacy mineral opacities. The digit was amputated and submitted for histology. No recurrence has been observed 7 months after amputation. PATHOLOGICAL AND MOLECULAR FINDINGS: Histology revealed a moderately well-circumscribed proliferation of well-differentiated squamous cells arranged in trabeculae and nests. Numerous thin spicules of osseous metaplasia were visible throughout the neoplasm. Around 70% of the neoplastic cells contained papillomavirus-induced cell changes including large amphophilic cytoplasmic bodies and cells with shrunken nuclei surrounded by a clear halo. Intense p16CDKN2A protein immunostaining was visible within the neoplastic cells, suggesting papillomavirus-induced changes in cell regulation. A DNA sequence from a putative novel Taupapillomavirus type was amplified from the neoplasm. DIAGNOSIS: Osteoinductive squamous cell carcinoma associated with a putative novel papillomavirus type. CLINICAL RELEVANCE: The findings in this case increase the number of papillomavirus types known to infect cats, and the squamous cell carcinoma had histological features that have not been previously reported. The neoplasm was not as invasive as is typical for a squamous cell carcinoma and excision appeared curative. This is the first report of an osteoinductive squamous cell carcinoma of the skin of cats and the neoplasm had a unique radiographic appearance.Item Skin thickness as a potential indirect trait for genetic improvement of lamb survival : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Animal Science at Massey University, Palmerston North, New Zealand(Massey University, 2021) Soltanighombavani, MasoudLamb survival, as a trait of great economic importance with low heritability, might show more response to indirect selection for traits of higher heritability that are genetically correlated with lamb survival, as a trait of high economic importance. The main objective of this thesis was to explore if ultrasonographically measured skin thickness (ST) at about nine months of age could be considered as an alternative to direct selection for lamb survival from birth to weaning (SBW). For this purpose, in the first step, the reliability of ultrasonography as an accurate and noninvasive method for measurement of ST was validated using plicometry and histometry. In the second experiment, the heritability of ultrasonographically measured ST at an age of about 9 months was estimated to be 0.21 ± 0.03 and 0.20 ± 0.03, respectively from analyses with and without adjustment for live weight at scanning (LWS), implying that the trait would respond to genetic selection. Estimates of genetic correlation of ST with SBW from the analyses with LWS considered as a covariate for ST ranged from 0.16 to 0.35 depending on the minimum number of progeny per sire for each trait, while the corresponding estimates from the analyses with LWS excluded ranged from 0.08 to 0.27. When correction was made for LWS, ST showed genetic correlations of 0.21 ± 0.07, -0.13 ± 0.09, -0.32 ± 0.12, -0.23 ± 0.09, -0.10 ± 0.10, 0.02 ± 0.11, and 0.20 ± 0.11 with fat depth (FD), eye muscle depth (EMD), weights at weaning (WWT), 8 months (LW8), scanning (LWS), and 12 months (LW12), and fleece weight at 12 months (FW12), respectively. The corresponding estimates when no adjustment was made for LWS, were respectively 0.24 ± 0.08, -0.08 ± 0.10, -0.01 ± 0.12, 0.09 ± 0.09, 0.19 ± 0.09, 0.30 ± 0.10, and 0.20 ± 0.11. In the third experiment, the role of skin thickness in thermoregulation through its effect on surface heat loss and a few other indices of cold resistance was explored in two groups of new-born lambs with the thickest skin (thick-skinned category) and the thinnest skin (thin-skinned category) exposed to cold-stress. As a result of lower skin surface temperature (as an indicator of heat loss) in thick-skinned lambs compared to thin-skinned lambs, the first group had higher rectal temperature and were more likely to maintain body temperature during cold stress, even though they produced significantly less heat (W Kg-1). This means there is less need to consume body reserves as a source of energy and consequently better conservation of body reserves in the thick-skinned lambs. In the fourth experiment, skin thickness measured at six to eight months of age was revealed to be a moderately reliable indicator of skin thickness at birth. This is of high importance from both practical and economic points of views. Measuring skin thickness at six to eight months of age is much easier than at birth for sheep farmers/breeders. Furthermore, ultrasound measurement of skin thickness at these ages facilitates simultaneous recording of other traits of importance like fat depth and eye muscle depth, which are normally taken at these ages. In the final study, the effects of genetic variation in the uncoupling protein 1 (UCP1), prolactin (PRL), and prolactin receptor (PRLR) genes on the indices of cold resistance were tested in new-born lambs exposed to cold stress. Although significant effects on some of the indices were observed at/during some time-points/periods of the cold stress, they seem to be mostly due to biases resulting from low number of lambs rather than being real. Considering all the findings, it could be generally concluded that ultrasonographically measured skin thickness at about nine months of age could be considered as a supplement to direct selection for lamb survival in genetic improvement programs. Nevertheless, the large standard errors of the correlations of ST with SBW as well as the unfavorable correlation of ST with other traits should also be considered.Item Epidemiological studies of bovine digital dermatitis in pasture-based dairy system in New Zealand : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Veterinary Sciences at Massey University, Palmerston North, New Zealand(Massey University, 2019) Yang, DanchenBovine digital dermatitis (BDD) is an infectious disease of the feet of cattle. Worldwide, it is one of the most commonly observed foot diseases on many dairy farms, and is the most important infectious cause of lameness in cattle in confined dairy system. Although BDD is generally less common in pasture-based dairy system it can still cause significant production losses and welfare issues, in such systems. This thesis contains seven original research works covering the epidemiological aspects of BDD in pasture-based cattle in New Zealand. Firstly, cross-sectional and longitudinal data obtained from Taranaki were analysed to identify the factors (including climate) associated with the disease. This was followed by a large scale cross-sectional study covering four regions in New Zealand looking at the prevalence of and risk factors for BDD. A longitudinal study was then undertaken on three farms in order to collect disease data (including BDD lesion type) over a lactation. Using this dataset, a deterministic compartment model was built to study the transmission dynamics of BDD within a dairy herd in New Zealand. Along with these large studies, two small validation studies were also carried out. The first study evaluated the agreement between two trained BDD observers in determining BDD presence/ absence in digital photographs, while the second one evaluated the reliability of clinical examination of BDD lesions in the milking parlour without prior washing of the animals’ feet. This work suggests that BDD has spread widely across New Zealand, although it has yet to reach the West Coast. In the four regions where BDD was identified, true between herd prevalences varied by region (from ~ 40% to > 65%). Furthermore, although BDD was found in many herds, true cow level prevalence was low in all affected regions, being generally less than 4% in affected herds. Several biosecurity related management practices were repeatedly identified as factors associated with increased BDD prevalence at both the herd and cow level. These included mixing heifers with animals from other properties; purchasing heifers for replacement and using outside staff to treat lame cows. In addition to the identified management practices, climate (rainfall and soil temperature) was also found to have had a significant association with the prevalence of BDD. These studies used examination in the milking parlour as the method of identifying BDD lesions. This method while the best method of lesion detection for large scale studies is not perfect. It generally requires that feet are washed prior to examination, as lesions masked by dirt are difficult to identify. Our study quantified the effect, under New Zealand conditions, of feet washing prior to examination finding sensitivities of 0.34 (95% credible interval [CrI]: 0.088-0.69) and 0.63 (95%CrI: 0.46- 0.78) for pre- and post-washing, respectively. There was a 93.95% probability that the sensitivity of examination post-washing was greater than that prewashing. Limited information on the reliability of examination in the milking parlour prompted comparison of two trained observers using digital photographs. Agreement between the two observers was good; we could be 75% sure that the two observers had almost perfect agreement and 95% sure the two observers had at least substantial agreement. It is crucial that since examination in the milking parlour is not a perfect reference test for detecting BDD lesions that when estimating prevalence, the sensitivity and specificity of this method is factored into the analysis. This is often achieved using an approach based on the binomial distribution. However, as the dairy herd is a finite population and the sampling of animals for BDD lesion is effectively sampling without replacement, the correct distribution to use is the hypergeometric one. This is computationally complex so the Bayesian superpopulation approach was developed to allow continued use of the binomial distribution. The superpopulation approach was used to estimate prevalence in this thesis, one of the first uses of this approach in the veterinary field. The appearance of BDD in New Zealand is different from that elsewhere. Most lesion have been observed are small grey, rubbery lesions which may or may not have thickened, darker edges. Less commonly larger, more proliferative lesions can also be found. Red active lesions are extremely rare. Post-treatment lesions are not a feature of the disease in New Zealand as lesions are treated only very rarely. Thus modelling approach used a BDD score system which focuses on early stage of BDD. This found that in infected dairy herds, although BDD prevalence will tend to increase year-on-year it is likely to remain relatively low (<18%) even after 10 years of within-herd transmission. It is likely that the low transmission rate during the late lactation (model assumption) results in more cases resolving than developing during this period and therefore results in the low prevalence of infectious cattle at the start of each subsequent lactation. Cattle with larger, more proliferative lesions had a stronger influence on the establishment and maintenance of DD than cattle with small lesions highlighting the importance of targeting these animals for intervention.Item Conversational skins : heirloom 'pelts' that emerge and evolve : an exegesis presented in partial fulfilment of the requirements for the degree of Master of Design at Massey University, Wellington, New Zealand(Massey University, 2015) Menzies, GretaFabric garments augment and transform the body as a second skin. This project is a poetic, heuristic inquiry that investigates taking this ‘second skin’ through multiple forms, transitioning between flat fabric, garment form, flat fabric, garment form etc. In this cyclical long-term relationship, the surface of the textile-skin is inscribed and augmented as cuts are made, and ‘healed’ through various textile processes. The scars write a story on the surface. There is a ceremonial sensation to removing and the ‘flattening’ the skin, which evokes the collection of a pelt. Using a phenomenological methodology the ‘flat’ and ‘form’ iterations are performed and photographed, growing a catalogue of the fabric’s evolution. Returning a garment to ‘flat’ offers erasure of form; it can become a level plane for a new construction. This action is achieved by utilising the method of ‘zero waste’ design, in which no fabric is removed in the construction of a garment. This enables the form to be unpicked, reassembled and sewn back to a flat-fabric state. The flat/ form/flat/form cycle is played out as a conversation with the cloth, responding to the flow and tendencies of each textile. The central proposition is that the flat-form-flat cycle provides a channel to engage in the transformative performance of dress, while enacting a use practice that diverges from problematic consumption models. In doing this, a unique surface pattern is inscribed on the cloth. The process asks: ‘what might be allowed to develop?’ The outcome demonstrates a collection of nine textile ‘pelts’ with documented progression; liminal pieces that are detailed artefacts in themselves, yet invite further interaction. Key Words: Textile Design, Speculative, Zero-waste, Shapeshift, Fashion, Skin, Transformation, Performance.Item A study of changes in the thickness and chemical composition of the skin of sheep during growth and after shearing : being a thesis presented in partial fulfillment of the requirements for the degree of M. Agr. Sc., Massey Agricultural College, University of New Zealand(Massey University, 1954) Wodzicka, Maria ManikaThis study reports on the development of a stochastic dynamic model to simulate a pastoral sheep enterprise. The event driven model was constructed using the iconic simulation package, ExtendTM. Events corresponded to the shifting of animals from one paddock to another. Each paddock was represented as a single entity with inherent attributes such as grazing area, sward characteristics and pasture production potential. The rotation sequence for grazing was determined by always allocating the flock of ewes, flock replacements or lambs to the paddock with the greatest pasture mass. Herbage mass was divided into three fractions: leaf, stem and dead. Pasture growth and senescence rates for individual paddocks were calculated from pasture leaf mass. A Micherlich-type function was used to relate leaf mass to total pasture growth. Senescence was assumed to increase linearly with herbage mass. Deterministic or stochastic pasture growth rate data can be generated by the model. Pasture responses to nitrogen were estimated dynamically and moderated for the farm by entering a user-defined response for a standard 50 kg/ha nitrogen application. Animal performance was calculated using average attributes for ewes, ewe hoggets and rams, but lambs were simulated individually. Lamb performance is affected by its date of birth and sex, and this information was generated by a sub-model for mixed-age ewe and ewe hogget reproduction. The potential herbage intake of the sheep was defined by their rumen fill and physiological energy demand, and herbage availability which was defined by pre-grazing green herbage mass and green herbage allowance for rotational grazing and leaf mass for continuous grazing. The grazing time spent in each paddock was derived from a linear interpolation of user-defined herbage allowances for each month of the year. The proportion of leaf, stem and dead material in the diet was calculated according to the proportion of these fractions in the sward and herbage availability. If animals were supplemented they consumed all of the material offered. This caused pasture substitution by decreasing the physiological energy demand and utilising rumen space otherwise taken up by grazed pasture. The partitioning of nutrients by animals was estimated from the ratio between energy intake and energy demand in an animal growth sub-model. This was driven by the DNA, protein and fat content of individual lambs and the average for animals in other sheep classes. Lambs were drafted for sale and graded according to user-defined threshold drafting weights. Carcass weight and fatness (GR) were generated from the live weight and sex of individuals lambs. A genetic optimisation algorithm was developed to optimise the systems control variables incorporated in the model. These were pasture allowance, supplement fed, nitrogen applied and lamb drafting weight. The model was evaluated against three New Zealand "farmlet" grazing experiments. This validation suggested re-parameterisation of the physiological intake limit is needed and that the British equation used to relate intake to leaf mass availability is overly sensible to the pasture conditions found in New Zealand. The model was also used to test the effects of pasture measurement errors on the profitability of a grazing system. Significant differences in profitability occurred when a CV of 40% in measurement of pasture mass was assumed (Gross margin = $NZ 495 /ha vs. $NZ 542 /ha and $NZ 570 /ha for 20 and 0% CV in measurement estimations and normal variability in pasture accumulation rates and Gross margin = $NZ 587 /ha, $NZ 576/ha and $NZ 519/ha, respectively for 40,20 and 0% CV in measurement estimates and no pasture accumulation rate variability). It was concluded that low gains in system performance can be expected by improving the accuracy of measuring pre-grazing herbage mass beyond the level (13-16% CV) provided by the correct use of current measurement techniques.Item Collagen dehydration(Elsevier BV, 1/09/2022) Haverkamp RG; Sizeland KH; Wells HC; Kamma-Lorger CType I collagen is a ubiquitous structural protein in animal tissues. It is normally present in a hydrated form. However, collagen is very dependent on associated water for its mechanical properties. In skin, where type I collagen is dominant, there is a longstanding concern that the skin and therefore collagen may partially dry out and result in structural degradation. Here we show that dehydration of type I collagen fibrils, using 2-propanol, results in a two-stage dehydration process. Initially, the fibrils do not change length, i.e. the D-period remains constant, but shrinkage occurs within the fibrils by an increase in the gap region and a decrease in the overlap region within a D-band and a shortening of the helical turn distance and fibril diameter. Only with further dehydration does the length of the collagen fibril decrease (a decrease in D-period). This mechanism explains why collagen materials are resistant to gross structural change in the early stages of dehydration and shows why they may then suffer from sudden external shrinkage with further dehydration.