Previous research has shown that dairy cows require a dry period of at least 40 d for maximal milk yield in the subsequent lactation. Reducing the dry period requirement could prove beneficial to animal health and dairy profitability if subsequent milk yield was not reduced. Studies were conducted to evaluate the effects of continuous milking (CM) and hormonal treatments on milk yield, mammary epithelial cell (MEC) turnover during late gestation and early lactation, and mammary gene expression in dairy cows. A commercial trial using primiparous and multiparous cows demonstrated equal milk yields in bST-supplemented, CM and 60-d dry (CTL) multiparous cows, but lower milk yields in bST-supplemented CM, primiparous cows treated with bST. Subsequent experiments evaluated mammary development requirements during the dry period in primiparous cows and methods of rescuing milk yield. MEC growth was lower in CM glands during most of late gestation. Maintenance of lactation in CM glands resulted in a marked reduction in the MEC turnover process that occurs in the early dry period. In the last 20 d of gestation, MEC growth remained reduced in CM glands. By the last week of gestation, MEC growth was 50% less in CM tissue vs. CTL tissue. MEC apoptosis was unaffected by CM during the last 20 d of gestation, but a premature decrease in early lactation apoptosis occurred in CM glands at 7 d postpartum. Mammary gene expression demonstrated bax and insulin-like growth factor binding protein 5 are involved in apoptosis and cyclin D1, CCAT/enhancer binding protein-β, and bcl2 are involved in mammary development. Ultrastructure of CM tissue revealed large populations of resting or involuting alveoli by d 20 postpartum, whereas CTL glands had a homogenous population of secretory alveoli. Collectively, these data suggest that a 40-53% reduction in milk yield in CM glands is caused by reductions in MEC renewal and reduced secretory capacity. Treatments (bST, prostaglandin E2) to stimulate milk synthesis or MEC growth in CM primiparous glands were unsuccessful. In conclusion, primiparous cows continue to require a 60-d dry period, but multiparous cows are good candidates for short dry periods, and potentially no dry period.

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We report on different addressing mechanisms for quasi-distributed absorption sensors based on the frequency modulated continuous wave (FMCW) method. The sensor units consist of open-path micro-optic cells constructed from GRIN lenses, each of differing lengths. Guided by initial simulations, two approaches are experimentally investigated and evaluated, namely reference arm addressing and coherence addressing. Reference arm addressing is accomplished by the selection of different length reference arms in a Michelson configuration where each reference arm corresponds to a certain sensing unit. Coherence addressing is achieved by the interferometric mixing of two signals originating from each cell (from the glass/air interfaces). For each method, we show theoretically and experimentally how individual cells can be addressed and the measured signals obtained by suitable choice of cell length, proper modulation of the source and appropriate signal processing. In order to improve sensitivity we present the theoretical analysis of a new scheme based on combining the (FMCW) technique with frequency modulation spectroscopy (FMS). Here we arrange for only one sideband of the rf-modulation to be attenuated by the absorption feature and a new signal, proportional to the absorbance, appears in the output spectrum at a frequency corresponding to the difference between the rf-modulation frequency and the beat frequency of a cell. The method is highly sensitive and applicable to a variety of chemical species with narrow absorption lines, such as in trace gas analysis. We present the mathematical analysis of the proposed method for single and multiple cell systems, using methane detection as an example.

High power diode-pumped solid state (DPSS) lasers are a rapidly growing technology that is attractive for various applications in scientific and industrial fields. DPSS lasers are highly efficient, reliable and durable with superior beam quality when compared to flash-lamp pumped solid state lasers. Double-tungstate crystal of neodymium-doped potassium gadolinium tungstate (Nd:KGW) is one of the most effective active media used in DPSS lasers for generation of continuous wave radiation and ultrashort (i.e. picosecond, 10-12 s) pulses. Unfortunately, the thermal conductivity of KGW host crystals is relatively low (~3 Wm-1K-1). This low thermal conductivity and large quantum defect while pumping with ~808 nm lead to significant thermo-optical distortions. One way to minimize thermo-optical distortions is to reduce the quantum defect. This can be done by pumping at longer wavelengths as compared to conventional 808 nm. In this work we demonstrate what we believe is the first continuous wave Nd:KGW laser with hot band diode pumping at ~910 nm. This pumping wavelength reduced the quantum defect by >46% as compared to the conventional ~808 nm pumping and resulted in significantly lower thermal lensing. The laser produced 2.9 W of average output power at 1067 nm in a diffraction limited beam for an absorbed pump power of 8.3 W. The slope efficiency and optical-to-optical efficiency were found to be 43% and 35%, respectively. Significant reduction of quantum defect offered by this pumping wavelength and availability of suitable high power laser diodes opens an attractive way to further power and efficiency scaling of the Nd:KGW lasers. / October 2016

Aim: To describe and analyse the epidemiology and management of asthma, atopy and related morbidity in a Scottish Primary Care population by exploiting the Continuous Morbidity Recording database. Methods: The patient information used in this thesis was extracted from the computerised data of general practices contributing to the Continuous Morbidity Recording project. Results: A significant increase in the prescribing of short-acting beta2 (p<0.005) and adjunct therapy prescribing (p<0.001) occurred over the four study years. There was a significant shift to treatment steps 3 and 4 of the British Asthma Guidelines (p<0.002) in asthma patients followed up over the four study years. Significant declines in the incidence of asthma were observed in children (p<0.001), with no apparent compensatory diagnostic shift. There was a significant increase in the risk of presenting with a Th1 mediated autoimmune condition in patients with a history of allergic disease. There was a particularly strong association between current psoriasis and current eczema. Conclusions: The concurrence of morbidity and prescribing epidemiology with external sources of data such as surveys suggest high quality of data stored by the Continuous Morbidity Recording database. General practitioners prescribed higher doses of inhaled corticosteroids and more new adjunct therapies during the study period, possibly due to the impact of new British Asthma Guidelines completed in 1995 and published in 1997. The decrease in asthma prevalence suggests that the burden of this disease on general practitioner workload is in decline. The decrease of the incidence of asthma gives the first indication of either a permanent or temporary decline of this disease in Scotland after reported increasing prevalences over several decades. The new finding that Th1 and Th2 mediated diseases are significantly associated in a large general practice population supports the proposal that these diseases share risk factors that increase the propensity of the immune system to generate both Th1 and Th2-mediated inappropriate responses to non-pathological antigens.

We prove two results; first, we show that a boundary value problem for the semilinear wave equation with smooth, asymptotically linear nonlinearity and sinusoidal smooth forcing along a characteristic cannot have a continuous solution. Thereafter, we show that if the sinusoidal forcing is not isolated to a characteristic of the wave equation, then the problem has a continuous solution.