Stereodynamical Control of a Quantum Scattering Resonance in Cold Molecular Collisions

Cold collisions of light molecules are often dominated by a single partial wave resonance. For the rotational quenching of HD (v=1, j=2) by collisions with ground state para-H2, the process is dominated by a single L=2 partial wave resonance centered around 0.1 K. Here, we show that this resonance can be switched on or off simply by appropriate alignment of the HD rotational angular momentum relative to the initial velocity vector, thereby enabling complete control of the collision outcome

The life and work of Thomas Laycock (1812-1876)

Following an introduction giving the reasons for writing on Thomas Laycock, there are two chapters of personal biography making use of his unpublished personal Journal. An account is then given of his papers on hysteria and the thinking which led from hysteria to reflex brain function. Next a chapter is devoted to Laycock's writings on public health and his involvement with Edwin Chadwick in the preparation for the City of York of The Report on the state of Large Towns and Populous Districts. Laycock always had a special interest in medical psychology and extended reflex action to explain some of the phenomena of mental illness and memory. An account is also given of his various other writings related to psychiatry. He was aware that extending reflex function to the brain would result in various philosophical and theological problems and Laycock's opinions are given on these issues together with a brief account of his classical work Mind and Brain. Having a great interest in medical psychology, also being a lecturer at the York Medical School and later Professor of the Practice of Physic at Edinburgh, it was natural he should be a pioneer in the teaching of the subject. Many fascinating ideas are to be found in Laycock's writings on general medicine, especially his use of neurology to explain oedema and certain types of pulmonary disease. A trophic nervous system was thought to cause tissue pathology which was a reversion to a lower evolutionary type. In his last decade Laycock wrote consolidating many of his previous ideas but attempted to bring these into line with then current scientific advances. A selection of his unpublished writings is examined in the same chapter. In his lifetime Laycock was not an influential person but he impressed a few of his more able students, several of whom were to become professionally distinguished. The careers of these are described. After some conclusions a bibliography, with notes. is provided of published and unpublished works used in this thesis

Morphological and molecular characterisation of a mixed Cryptosporidium muris/Cryptosporidium felis infection in a cat

To date Cryptosporidium muris has been identified by microscopy and genotyping in cats in two studies. We report morphological and genetic evidence of a mixed C. muris and C. felis infection in a cat and provide the first histological, immunohistochemical, in situ hybridisation and genetic confirmation of a C. muris infection in the stomach of a cat. The cat suffered persistent diarrhoea after the initial consultation, which remained unresolved, despite several medical interventions. Further studies are required to determine the range, prevalence and clinical impact of Cryptosporidium species infecting cats

Building an ex vivo model of breast cancer lung metastasis

Cell cultures are traditionally studied as 2D monolayers with use of 3D culture systems gradually becoming more prevalent. The advantages of 3D culture over traditional methods are numerous as they: do not force apical-basal cell polarity, allow the formation of 3D cell structure and allow the study of complex microenvironments, amongst others. The study of biological processes can be hindered by the limitations of monolayer culture. One such process is the metastasis of malignant cells, which requires understanding of different chronological biological processes for efficacious secondary tumour formation. This thesis shows how the many biological events occurring during metastasis can be broken down and subsequently scrutinised by traditional methods, to gain insight into the strategies employed by different breast cancer sub types. Understanding each individual process alone has led to significant gains in our understating of metastasis, bringing all components together is now possible when integrating cells into a bioreactor 3D culture system. Findings here have shown the metastatic strategies of ‘luminal A’ breast cancer is delamination whilst triple negative ‘basal B’ breast cancers used a nomadic, single-cell strategy. It was found that the single-cell strategy induced large changes in phenotype when cells were cultured in suspension, including an increased resistance to paclitaxel, mitochondrial health and resistance to anoikis, and a ‘suspended animation’ phenotype. Importantly, these behaviours were seen to revert to a migratory, proliferative phenotype upon re-adherence to a substrate. These findings were then tested in 3D culture systems. Embryonic lung fibroblast organoids were first tested as a 3D substrate before decellularised rat lung matrices were selected as the most representative. Rat decellularised lung matrix was tested as a substrate for mimicking metastasis in the context of bioreactor system which allowed the transfer of cells from one matrix to another via the flow of media. This thesis shows that reconstituting models of metastasis is possible outside of animal models

Controlling Rotational Quenching Rates in Cold Molecular Collisions

The relative orientation and alignment of colliding molecules plays a key role in determining the rates of chemical processes. Here, we examine in detail a prototypical example: rotational quenching of HD in cold collisions with H2. We show that the rotational quenching rate from j = 2 → 0, in the v = 1 vibrational level, can be maximized by aligning the HD along the collision axis and can be minimized by aligning the HD at the so called magic angle. This follows from quite general helicity considerations and suggests that quenching rates for other similar systems can also be controlled in this manner

A study of the centrally produced pi0pi0pi0 channel in pp interactions at 450 GeV/c

The reaction pp -> pf (pi0pi0pi0) ps has been studied at 450 GeV/c. The pi0pi0pi0 effective mass spectrum shows clear eta(547) and pi2(1670) signals. Branching ratios for the eta(547) and pi_2(1670) are given as well as upper limits for the decays of the omega(782), a1(1260) and a2(1320) into 3pi0.Comment: 10 pages, Latex, 4 Figure

The Isgur-Wise function in a relativistic model for qQˉq\bar Q system

We use the Dirac equation with a ``(asymptotically free) Coulomb + (Lorentz scalar) linear '' potential to estimate the light quark wavefunction for $q\bar Q$ mesons in the limit $m_Q\to \infty$. We use these wavefunctions to calculate the Isgur-Wise function $\xi (v.v^\prime )$ for orbital and radial ground states in the phenomenologically interesting range $1\leq v.v^ \prime \leq 4$. We find a simple expression for the zero-recoil slope, $\xi^ \prime (1) =-1/2- \epsilon^2 /3$, where $\epsilon$ is the energy eigenvalue of the light quark, which can be identified with the $\bar\Lambda$ parameter of the Heavy Quark Effective Theory. This result implies an upper bound of $-1/2$ for the slope $\xi^\prime (1)$. Also, because for a very light quark $q (q=u, d)$ the size $\sqrt {}$ of the meson is determined mainly by the ``confining'' term in the potential $(\gamma_\circ \sigma r)$, the shape of $\xi_{u,d}(v.v^\prime )$ is seen to be mostly sensitive to the dimensionless ratio $\bar \Lambda_{u,d}^2/\sigma$. We present results for the ranges of parameters $150 MeV <\bar \Lambda_{u,d} <600 MeV$ $(\bar\Lambda_s \approx \bar\Lambda_{u,d}+100 MeV)$, $0.14 {GeV}^2 \leq \sigma \leq 0.25 {GeV}^2$ and light quark masses $m_u, m_d \approx 0, m_s=175 MeV$ and compare to existing experimental data and other theoretical estimates. Fits to the data give: ${\bar\Lambda_{u,d}}^2/\sigma =4.8\pm 1.7$, $-\xi^\prime_{u,d}(1)=2.4\pm 0.7$ and $\vert V_{cb} \vert \sqrt {\frac {\tau_B}{1.48 ps}}=0.050\pm 0.008$ [ARGUS '93]; ${\bar\Lambda_{u,d}}^2/\sigma = 3.4\pm 1.8$, $-\xi^\prime_{u,d}(1)=1.8\pm 0.7$ and $\vert V_{cb} \vert \sqrt { \frac {\tau_B}{1.48 ps}}=0.043\pm 0.008$ [CLEO '93]; ${\bar\Lambda_{u,d}}^2/Comment: 22 pages, Latex, 4 figures (not included) available by fax or via email upon reques

Net positive outcomes for nature

Much research and policy effort is being expended on seeking ways to conserve living nature while enabling the economic and social development needed to increase global equity and end poverty. We propose that this will only be possible if the language of policy shifts away from setting conservation targets that focus on avoiding losses and towards developing processes that consider net outcomes for biodiversity

Moderate drinking before the unit: medicine and life assurance in Britain and the US c.1860–1930

This article describes the way in which “Anstie’s Limit” – a particular definition of moderate drinking first defined in Britain in the 1860s by the physician Francis Edmund Anstie (1833–1874) – became established as a useful measure of moderate alcohol consumption. Becoming fairly well-established in mainstream Anglophone medicine by 1900, it was also communicated to the public in Britain, North America and New Zealand through newspaper reports. However, the limit also travelled to less familiar places, including life assurance offices, where a number of different strategies for separating moderate from excessive drinkers emerged from the dialogue between medicine and life assurance. Whilst these ideas of moderation seem to have disappeared into the background for much of the twentieth century, re-emerging as the “J-shaped” curve, these early developments anticipate many of the questions surrounding uses of the “unit” to quantify moderate alcohol consumption in Britain today. The article will therefore conclude by exploring some of the lessons of this story for contemporary discussions of moderation, suggesting that we should pay more attention to whether these metrics work, where they work and why