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Genetic analysis of a heritage variety collection
J. M. Preston, B. V. Ford-Lloyd, L. M. J. Smith, R. Sherman, N. Munro, N. Maxted
Journal: Plant Genetic Resources / Volume 17 / Issue 3 / June 2019
Published online by Cambridge University Press: 11 December 2018, pp. 232-244
Landraces (including heritage varieties) are an important agrobiodiversity resource offering considerable value as a buffer against crop failures, as a crop for niche markets, and as a source of diversity for crop genetic improvement activities underpinning future food security. Home gardens are reservoirs of landrace diversity, but some of the accessions held in them are vulnerable or threatened with extinction. Those associated with seed saving networks have added security, for example, ca. 800 varieties are stored in the Heritage Seed Library (HSL) of Garden Organic, UK. In this study, Amplified Fragment Length Polymorphisms-based genetic analysis of accessions held in the HSL was used to (a) demonstrate the range of diversity in the collection, (b) characterize accessions to aid collection management and (c) promote broader use of the collection. In total, 171 accessions were included from six crops: Vicia faba L., Pisum sativum L., Daucus carota L., Cucumis sativus L., Lactuca sativa L. and Brassica oleracea L. var. acephala (DC.) Metzq. Average expected heterozygosity ranged from 0.18 to 0.28 in D. carota; 0.02–0.18 in P. sativum; 0.05–0.18 in L. sativa; 0.15–0.26 in B. oleracea var. acephala; 0.15–0.37 in C. sativus and 0.07–0.36 in V. faba. Genetic diversity and Fst values generally reflected the breeding system and cultivation history of the different crops. Comparisons of the diversity found in heritage varieties with that found in commercial varieties did not show a consistent pattern. Principal coordinates analysis and Unweighted Pair Group Method with Arithmetic Mean cluster analysis were used to identify four potential duplicate accession pairs.
The initial development of a jet caused by fluid, body and free surface interaction. Part 5. Parasitic capillary waves on an initially horizontal surface
J. Billingham, D. J. Needham, E. Korsukova, R. J. Munro
In Part 3 of this series of papers (Needham et al., Q. J. Mech. Appl. Maths, vol. 61, 2008, pp. 581–614), we studied the free surface flow generated in a horizontal layer of inviscid fluid when a flat, rigid plate, inclined at an external angle $\unicode[STIX]{x1D6FC}$ to the horizontal, is driven into the fluid with a constant, horizontal acceleration. We found that the most interesting behaviour occurs when $\unicode[STIX]{x1D6FC}>\unicode[STIX]{x03C0}/2$ (the plate leaning into the fluid). When $\unicode[STIX]{x03C0}/2<\unicode[STIX]{x1D6FC}\leqslant \unicode[STIX]{x1D6FC}_{c}$ , with $\unicode[STIX]{x1D6FC}_{c}\approx 102.6^{\circ }$ , we were able to find the small-time asymptotic solution structure, and solve the leading-order problem numerically. When $\unicode[STIX]{x1D6FC}=\unicode[STIX]{x1D6FC}_{c}$ , we found numerical evidence that a $120^{\circ }$ corner exists on the free surface, at leading order as $t\rightarrow 0$ . For $\unicode[STIX]{x1D6FC}>\unicode[STIX]{x1D6FC}_{c}$ , we could find no numerical solution of the leading-order problem as $t\rightarrow 0$ , and hypothesised that the solution does not exist for any $t>0$ for these values of $\unicode[STIX]{x1D6FC}$ . At the present time, there is no rigorous proof of this hypothesis. In this paper, we demonstrate that the likely non-existence of a solution for any $t>0$ when $\unicode[STIX]{x1D6FC}>\unicode[STIX]{x1D6FC}_{c}$ can be reconciled with the physics of the system by including the effect of surface tension in the model. Specifically, we find that for $\unicode[STIX]{x1D6FC}>\unicode[STIX]{x1D6FC}_{c}$ , the solution exists for $0\leqslant t<t_{c}$ , with $t_{c}\sim Bo^{-1/(3\unicode[STIX]{x1D6FE}-1)}\unicode[STIX]{x1D70F}_{c}$ and $\unicode[STIX]{x1D70F}_{c}=O(1)$ as $Bo^{-1}\rightarrow 0$ , where $Bo$ is the Bond number ( $Bo^{-1}$ is the square of the ratio of the capillary length to the fluid depth) and $\unicode[STIX]{x1D6FE}\equiv 1/(1-\unicode[STIX]{x03C0}/4\unicode[STIX]{x1D6FC})$ . The solution does not exist for $t\geqslant t_{c}$ due to a topological transition driven by a nonlinear capillary wave, i.e. the free surface pinches off (self-intersects) when $t=t_{c}$ . We are also able to compare this asymptotic solution with experimental results which show that, in an experimental case where the contact angle remains approximately constant (the modelling assumption that we make in this paper), the asymptotic solution is in good agreement. In general, the inclusion of surface tension leads to the generation of capillary waves ahead of the wavecrest, which decay as $t$ increases for $\unicode[STIX]{x1D6FC}<\unicode[STIX]{x1D6FC}_{c}$ but dominate the flow and lead to pinch-off for $\unicode[STIX]{x1D6FC}>\unicode[STIX]{x1D6FC}_{c}$ . These capillary waves are an unsteady analogue of the parasitic capillary waves that can be generated ahead of steadily propagating, periodic capillary–gravity waves, e.g. Lin & Rockwell (J. Fluid Mech., vol. 302, 1995, pp. 29–44).
Associations of rumen parameters with feed efficiency and sampling routine in beef cattle
S. Lam, J. C. Munro, M. Zhou, L. L. Guan, F. S. Schenkel, M. A. Steele, S. P. Miller, Y. R. Montanholi
Journal: animal / Volume 12 / Issue 7 / July 2018
Characterizing ruminal parameters in the context of sampling routine and feed efficiency is fundamental to understand the efficiency of feed utilization in the bovine. Therefore, we evaluated microbial and volatile fatty acid (VFA) profiles, rumen papillae epithelial and stratum corneum thickness and rumen pH (RpH) and temperature (RT) in feedlot cattle. In all, 48 cattle (32 steers plus 16 bulls), fed a high moisture corn and haylage-based ration, underwent a productive performance test to determine residual feed intake (RFI) using feed intake, growth, BW and composition traits. Rumen fluid was collected, then RpH and RT logger were inserted 5.5±1 days before slaughter. At slaughter, the logger was recovered and rumen fluid and rumen tissue were sampled. The relative daily time spent in specific RpH and RT ranges were determined. Polynomial regression analysis was used to characterize RpH and RT circadian patterns. Animals were divided into efficient and inefficient groups based on RFI to compare productive performance and ruminal parameters. Efficient animals consumed 1.8 kg/day less dry matter than inefficient cattle (P⩽0.05) while achieving the same productive performance (P⩾0.10). Ruminal bacteria population was higher (P⩽0.05) (7.6×1011 v. 4.3×1011 copy number of 16S rRNA gene/ml rumen fluid) and methanogen population was lower (P⩽0.05) (2.3×109 v. 4.9×109 copy number of 16S rRNA gene/ml rumen fluid) in efficient compared with inefficient cattle at slaughter with no differences (P⩾0.10) between samples collected on-farm. No differences (P⩾0.10) in rumen fluid VFA were also observed between feed efficiency groups either on-farm or at slaughter. However, increased (P⩽0.05) acetate, and decreased (P⩽0.05) propionate, butyrate, valerate and caproate concentrations were observed at slaughter compared with on-farm. Efficient had increased (P⩽0.05) rumen epithelium thickness (136 v. 126 µm) compared with inefficient cattle. Efficient animals also spent 318% and 93.2% more time (P⩽0.05) in acidotic (4.14% v. 1.30%) (pH⩽5.6) and optimal (5.6<pH<6.0) (8.53% v. 4.42%) RpH range compared with inefficient cattle. The circadian patterns revealed lower (P⩽0.05) RpH and no differences (P⩾0.10) in RT pre-, during, and post-prandial periods in efficient compared with inefficient cattle. In essence, superior feed efficiency in cattle seems linked to rumen features consistent with improved efficiency of feed utilization. Microbial abundance, rumen epithelial histomorphology, and RpH, may serve as indicators for feed efficiency in cattle. The divergences of assessments made on-farm and at slaughter should be considered in the development of proxies for feed efficiency.
Experimental study of oscillating-grid turbulence interacting with a solid boundary
Mark W. McCorquodale, R. J. Munro
The interaction between oscillating-grid turbulence and a solid, impermeable boundary (positioned below, and aligned parallel to, the grid) is studied experimentally. Instantaneous velocity measurements, obtained using two-dimensional particle imaging velocimetry in the vertical plane through the centre of the (horizontal) grid, are used to study the effect of the boundary on the root-mean-square velocity components, the vertical flux of turbulent kinetic energy (TKE) and the terms in the Reynolds stress transport equation. Identified as a critical aspect of the interaction is the blocking of a vertical flux of TKE across the boundary-affected region. Terms of the Reynolds stress transport equations show that the blocking of this energy flux acts to increase the boundary-tangential turbulent velocity component, relative to the far-field trend, but not the boundary-normal velocity component. The results are compared with previous studies of the interaction between zero-mean-shear turbulence and a solid boundary. In particular, the data reported here are in support of viscous and 'return-to-isotropy' mechanisms governing the intercomponent energy transfer previously proposed, respectively, by Perot & Moin (J. Fluid Mech., vol. 295, 1995, pp. 199–227) and Walker et al. (J. Fluid Mech., vol. 320, 1996, pp. 19–51), although we note that these mechanisms are not independent of the blocking of energy flux and draw parallels to the related model proposed by Magnaudet (J. Fluid Mech., vol. 484, 2003, pp. 167–196).
The spin-up of a linearly stratified fluid in a sliced, circular cylinder
R. J. Munro, M. R. Foster
Journal: Journal of Fluid Mechanics / Volume 806 / 10 November 2016
Published online by Cambridge University Press: 30 September 2016, pp. 254-303
Print publication: 10 November 2016
A linearly stratified fluid contained in a circular cylinder with a linearly sloped base, whose axis is aligned with the rotation axis, is spun-up from a rotation rate $\unicode[STIX]{x1D6FA}-\unicode[STIX]{x0394}\unicode[STIX]{x1D6FA}$ to $\unicode[STIX]{x1D6FA}$ (with $\unicode[STIX]{x0394}\unicode[STIX]{x1D6FA}\ll \unicode[STIX]{x1D6FA}$ ) by Rossby waves propagating across the container. Experimental results presented here, however, show that if the Burger number $S$ is not small, then that spin-up looks quite different from that reported by Pedlosky & Greenspan (J. Fluid Mech., vol. 27, 1967, pp. 291–304) for $S=0$ . That is particularly so if the Burger number is large, since the Rossby waves are then confined to a region of height $S^{-1/2}$ above the sloped base. Axial vortices, ubiquitous features even at tiny Rossby numbers of spin-up in containers with vertical corners (see van Heijst et al. Phys. Fluids A, vol. 2, 1990, pp. 150–159 and Munro & Foster Phys. Fluids, vol. 26, 2014, 026603, for example), are less prominent here, forming at locations that are not obvious a priori, but in the 'western half' of the container only, and confined to the bottom $S^{-1/2}$ region. Both decay rates from friction at top and bottom walls and the propagation speed of the waves are found to increase with $S$ as well. An asymptotic theory for Rossby numbers that are not too large shows good agreement with many features seen in the experiments. The full frequency spectrum and decay rates for these waves are discussed, again for large $S$ , and vertical vortices are found to occur only for Rossby numbers comparable to $E^{1/2}$ , where $E$ is the Ekman number. Symmetry anomalies in the observations are determined by analysis to be due to second-order corrections to the lower-wall boundary condition.
Associations of acute stress and overnight heart rate with feed efficiency in beef heifers
J. C. Munro, F. S. Schenkel, P. W. Physick-Sheard, A. B. P. Fontoura, S. P. Miller, T. Tennessen, Y. R. Montanholi
Journal: animal / Volume 11 / Issue 3 / March 2017
Proxies have the potential to accelerate feed efficiency (residual feed intake (RFI); kg dry matter/day) improvement, assisting with the reduction of beef cattle feed costs and environmental impact. Heart rate (HR) (beats per minute (BPM)) is associated with feed efficiency and influenced by autonomic activity and peripheral metabolism, suggesting HR could be used as a proxy for feed efficiency. Objectives were to assess associations between overnight HR, lying patterns and RFI, and between acute stress HR and RFI. Heifer calves (n=107; 408±28 days of age, 341±42.2 kg) and yearling heifers (n=36; 604±92 days of age, 539±52.2 kg) were exposed to a performance test to determine productive performance. Overnight HR (electrode based) and lying patterns (accelerometer based) were monitored on a subgroup of heifer calves (n=40; 20 lowest RFI; 20 highest RFI). In the 10-min acute stress assessment, all heifers were individually exposed to the opening and closing of an umbrella and HR before (HRBEF), in response to (HRMAX), after (HRAFT) and change (HRCHG; HRAFT−HRBEF) as a result of exposure were determined. Using polynomial regression, rate of HR decrease pre-exposure (β 1) and rates of HR increase (β 2) and decrease (β 3, β 4) post-exposure were determined. Heifer calves in the overnight assessment were classified into equal RFI groups (low RFI; high RFI) and HR means were treated as repeated measures and compared using multiple regression. In the acute stress assessment, heifers were classified within cattle category into equal RFI groups (low RFI; high RFI) and means and polynomial regression parameters were compared using multiple regression. Low-RFI heifer calves had a lower overnight HR (69.2 v. 72.6 BPM), similar HR change from lying to standing intervals (8.9 v. 9.2 BPM) and similar time lying (61.1% v. 64.5%) compared with high-RFI heifer calves. Low-RFI heifer calves had a higher absolute HRMAX (162.9 v. 145.7 BPM) and β 2 (−0.34 v. −0.20) than high-RFI heifer calves. Low-RFI yearling heifers had similar acute stress HR means and a lower β 1 (0.003 v. 0.006) than high-RFI yearling heifers. Overnight HR and acute stress HR are potential indicators of RFI in heifer calves. However, acute stress HR results varied in yearling heifers, suggesting previous handling experience and/or age influence stress response. Pending further development (predictive ability, repeatability), the acute stress assessment could have potential for on-farm application as a feed efficiency proxy in young heifers with minimal handling experience.
On the formation of axial corner vortices during spin-up in a cylinder of square cross-section
R. J. Munro, R. E. Hewitt, M. R. Foster
Journal: Journal of Fluid Mechanics / Volume 772 / 10 June 2015
Print publication: 10 June 2015
We present experimental and theoretical results for the adjustment of a fluid (homogeneous or linearly stratified), which is initially rotating as a solid body with angular frequency ${\it\Omega}-{\rm\Delta}{\it\Omega}$ , to a nonlinear increase ${\rm\Delta}{\it\Omega}$ in the angular frequency of all bounding surfaces. The fluid is contained in a cylinder of square cross-section which is aligned centrally along the rotation axis, and we focus on the $O(\mathit{Ro}^{-1}{\it\Omega}^{-1})$ time scale, where $\mathit{Ro}={\rm\Delta}{\it\Omega}/{\it\Omega}$ is the Rossby number. The flow development is shown to be dominated by unsteady separation of a viscous sidewall layer, leading to an eruption of vorticity that becomes trapped in the four vertical corners of the container. The longer-time evolution on the standard 'spin-up' time scale, $E^{-1/2}{\it\Omega}^{-1}$ (where $E$ is the associated Ekman number), has been described in detail for this geometry by Foster & Munro (J. Fluid Mech., vol. 712, 2012, pp. 7–40), but only for small changes in the container's rotation rate (i.e. $\mathit{Ro}\ll 1$ ). In the linear case, for $\mathit{Ro}\ll E^{1/2}\ll 1$ , there is no sidewall separation. In the present investigation we focus on the fully nonlinear problem, $\mathit{Ro}=O(1)$ , for which the sidewall viscous layers are Prandtl boundary layers and (somewhat unusually) periodic around the container's circumference. Some care is required in the corners of the container, but we show that the sidewall boundary layer breaks down (separates) shortly after an impulsive change in rotation rate. These theoretical boundary-layer results are compared with two-dimensional Navier–Stokes results which capture the eruption of vorticity, and these are in turn compared to laboratory observations and data. The experiments show that when the Burger number, $S=(N/{\it\Omega})^{2}$ (where $N$ is the buoyancy frequency), is relatively large – corresponding to a strongly stratified fluid – the flow remains (horizontally) two-dimensional on the $O(\mathit{Ro}^{-1}{\it\Omega}^{-1})$ time scale, and good quantitative predictions can be made by a two-dimensional theory. As $S$ was reduced in the experiments, three-dimensional effects were observed to become important in the core of each corner vortex, on this time scale, but only after the breakdown of the sidewall layers.
Lifecourse patterns of protein consumption and physical capability in later life
C. A. Munro, A. J. Adamson, A. M. Stephen, D. Kuh, R. Cooper, John C. Mathers
Last Words on Lucilius
from No. XVIII
By R. Ellis, H. A. J. Munro
Edited by William Aldis Wright, Ingram Bywater, Henry Jackson
Book: The Journal of Philology
The linear spin-up of a stratified, rotating fluid in a square cylinder
M. R. Foster, R. J. Munro
Published online by Cambridge University Press: 14 September 2012, pp. 7-40
Here we present experimental and theoretical results for how a stratified fluid, initially rotating as a solid body with constant angular velocity, $\Omega $ , within a closed cylinder of square cross-section, is spun up when subject to a small, impulsive increase, $ \mrm{\Delta} \Omega $ , in the cylinder's rotation rate. The fluid's adjustment to the new state of solid rotation can be characterized by: (a) an inviscid, horizontal starting flow which conserves the vorticity of the initial condition; (b) the eruption of Ekman layer fluid from the perimeter region of the cylinder's base and lid; (c) horizontal-velocity Rayleigh layers that grow into the interior from the container's sidewalls; and (d) the formation and decay of columnar vortices in the vertical corner regions. Asymptotic results describe the inviscid starting flow, and the subsequent interior spin-up that occurs due to the combined effects of Ekman suction through the base and lid Ekman layers, and the growth of the sidewall Rayleigh layers. Attention is focused on the flow development over the spin-up time scale ${T}_{s} = {E}^{\ensuremath{-} 1/ 2} {\Omega }^{\ensuremath{-} 1} $ , where $E$ is the Ekman number. (The spin-up process over the much longer diffusive time scale, ${T}_{d} = {E}^{\ensuremath{-} 1} {\Omega }^{\ensuremath{-} 1} $ , is not considered here.) Experiments were performed using particle imaging velocimetry (PIV) to measure horizontal velocity components at fixed heights within the flow interior and at regular stages during the spin-up period. The velocity data obtained are shown to be in excellent agreement with the asymptotic theory.
Correlation of nanoindentation-induced deformation microstructures in diamondlike carbon coatings on silicon substrates with simulation studies
Ayesha J. Haq, Paul R. Munroe, Mark Hoffman, Phil J. Martin, Avi Bendavid
Journal: Journal of Materials Research / Volume 25 / Issue 5 / May 2010
The effect of the presence of diamondlike carbon coatings deposited on (100) Si substrates on the deformation mechanisms operating in the silicon substrate during contact loading have been investigated by both cross-sectional transmission electron microscopy and modeling of the stresses generated beneath the indenter tip. The observed subsurface microstructures were correlated to the Tresca shear stress and the hydrostatic stress generated in the silicon substrate beneath the indenter tip. The presence of the coating altered the stresses generated in the substrate, and changed the deformation mechanism from one of principally phase transformation in uncoated Si to predominantly dislocation motion in the silicon substrate for the diamondlike C–Si system. The magnitude and distribution of the shear and hydrostatic stresses in the substrate were found to depend on both the indentation load and the thickness of the coating. Furthermore, the observed width of deformation, parallel to the interface, which was found to increase with coating thickness, was correlated to the wider distribution of the Tresca shear stress in the substrate brought about by the presence of the coating.
Is E-conferencing a useful communication tool in education and could it be used to promote health and wellbeing?
N. Fordyce, C. Munro, E. Hepburn, S. Ramnarine, J. Mcnulty, K. Cheng, S. Brown, D. Keith, D. Jones, M. R. Ritchie
Old and new techniques together resolve a problem of infection by Salmonella typhimurium
D. J. Platt, D. J. Brown, D. C. Old, R. M. Barker, D. S. Munro, J. Taylor
Journal: Epidemiology & Infection / Volume 99 / Issue 1 / August 1987
Isolates of Salmonella typhimurium, recovered over a 9-month period from a child with gastroenteritis, were characterized by biotyping, phage-typing and plasmid-profile analysis. Because the data from the different methods were discrepant, it was difficult to establish whether her infection was due to a single strain that had changed character in vivo or was due to recurrent infections with different, unrelated strains. Restriction-enzyme fingerprinting of the plasmids from the different isolates provided an explanation for the initial discrepancy and highlighted a source of potential confusion in epidemiological studies.
6 - The morphology and sedimentology of landforms created by subglacial megafloods
By Mandy J. Munro-Stasiuk, John Shaw, Darren B. Sjogren, Tracy A. Brennand, Timothy G. Fisher, David R. Sharpe, Philip S.G. Kor, Claire L. Beaney, Bruce B. Rains
Edited by Devon M. Burr, University of Tennessee, Paul A. Carling, University of Southampton, Victor R. Baker, University of Arizona
Book: Megaflooding on Earth and Mars
Print publication: 24 September 2009, pp 78-103
Subglacial landforms across various scales preserve the history of movement, deposition and erosion by the last great ice sheets and their meltwater. The origin of many of these landforms is, however, contentious. In this chapter these forms are described both individually and as suites that make up entire landscapes. Their interpretations are discussed with reference to the megaflood hypothesis. A description is provided of individual forms via their size, shape, landform associations, sedimentology and the relationship between landform surfaces and internal sediments. The possible origins of each are then discussed. To simplify the chapter the landforms are categorised by their size (micro, meso, macro and mega), although, importantly, it should be noted that several landforms show similarities across scales. Also discussed is the relevant subglacial hydrology associated with the described forms, especially the volume and discharge rates of megaflood flows, and where water may have been stored prior to the megaflood events.
As early as 1812, Sir James Hall interpreted the famous Castle Rock in Edinburgh, Scotland, a crag and tail, as a landform created by immense, turbulent floods. Likening the hill to features carved in snow by wind, he could only hypothesise that water was responsible; probably giant tidal waves, as, at that time, he knew of no other mechanism that could conceivably create such streamlining. It is now very clear that the streamlined forms first noted by Hall are part of a continuum containing landforms of many shapes and sizes.
Intrusive gravity currents from finite-length locks in a uniformly stratified fluid
J. R. MUNROE, C. VOEGELI, B. R. SUTHERLAND, V. BIRMAN, E. H. MEIBURG
Journal: Journal of Fluid Mechanics / Volume 635 / 25 September 2009
Print publication: 25 September 2009
Gravity currents intruding into a uniformly stratified ambient are examined in a series of finite-volume full-depth lock-release laboratory experiments and in numerical simulations. Previous studies have focused on gravity currents which are denser than fluid at the bottom of the ambient or on symmetric cases in which the intrusion is the average of the ambient density. Here, we vary the density of the intrusion between these two extremes. After an initial adjustment, the intrusions and the internal waves they generate travel at a constant speed. For small departures from symmetry, the intrusion speed depends weakly upon density relative to the ambient fluid density. However, the internal wave speed approximately doubles as the waves change from having a mode-2 structure when generated by symmetric intrusions to having a mode-1 structure when generated by intrusions propagating near the bottom. In the latter circumstance, the interactions between the intrusion and internal waves reflected from the lock-end of the tank are sufficiently strong and so the intrusion stops propagating before reaching the end of the tank. These observations are corroborated by the analysis of two-dimensional numerical simulations of the experimental conditions. These reveal a significant transfer of available potential energy to the ambient in asymmetric circumstances.
Lyme disease: a search for a causative agent in ticks in south–eastern Australia
R. C. Russell, S. L. Doggett, R. Munro, J. Ellis, D. Avery, C. Hunt, D. Dickeson
Journal: Epidemiology & Infection / Volume 112 / Issue 2 / April 1994
Attempts were made to identify the causative organism of Lyme disease in Australia from possible tick vectors.
Ticks were collected in coastal areas of New South Wales, Australia, from localities associated with putative human infections. The ticks were dissected; a portion of the gut contents was examined for spirochaetes by microscopy, the remaining portion inoculated into culture media. The detection of spirochaetes in culture was performed using microscopy, and immunochemical and molecular (PCR) techniques. Additionally, whole ticks were tested with PCR for spirochaetes.
From 1990 to 1992, approximately 12000 ticks were processed for spirochaetes. No evidence of Borrelia burgdorferi or any other spirochaete was recovered from or detected in likely tick vectors. Some spirochaete–like objects detected in the cultures were shown to be artifacts, probably aggregates of bacterial flagellae.
There is no definitive evidence for the existence in Australia of B. burgdorferi the causative agent of true Lyme disease, or for any other tick–borne spirochaete that may be responsible for a local syndrome being reported as Lyme disease.
UK regional paediatric home parenteral nutrition (HPN) data suggest a national underestimate in service requirements
A. R. Barclay, C. E. Paxton, J. Livingstone, D. Hoole, F. Munro, P. Gillett, D. C. Wilson
Journal: Proceedings of the Nutrition Society / Volume 67 / Issue OCE3 / May 2008
Published online by Cambridge University Press: 04 July 2008, E140
Indentation-Induced Damage Mechanisms in Germanium
David J Oliver, Jodie E Bradby, Jim S Williams, Michael V Swain, Damien McGrouther, Paul Munroe
Published online by Cambridge University Press: 26 February 2011, 0983-LL08-02
The response of crystalline Ge to indentation has been studied over a range of maximum loads. At a certain load, an unusual 'giant pop-in' event occurs, in which a discontinuous extension of >1 μm is observed in the force-displacement curve. In such cases, load release curves show a pronounced 'elbowing' response, leading to increased depth recovery. TEM and Raman microspectroscopy revealed the presence of amorphous material in the residual impression. To examine cracking, a sequence of cross-sections was milled through the indent and images taken using an automated method (the 'slice-and-view' method). Using 3-D reconstruction software, the data was segmented and reconstructed into a 3-dimensional representation of the cracks around the indent. Applying this technique to indents featuring a giant pop-in, it was deduced that the inelastic elbowing observed was a bending response of material detached by lateral cracking. The giant pop-in is attributable to material removal, caused by lateral cracks formed during loading.
Microstructure of a Spinodal Fe-Ni-Mn-Al Alloy
I Baker, J A Hanna, M W Wittmann, P R Munroe
Journal: Microscopy and Microanalysis / Volume 11 / Issue S02 / August 2005
Published online by Cambridge University Press: 01 August 2005, pp. 1864-1865
Print publication: August 2005
Extended abstract of a paper presented at Microscopy and Microanalysis 2005 in Honolulu, Hawaii, USA, July 31--August 4, 2005
Identification of a cryptic lethal mutation in the mouse tw73 haplotype
GARETH R. HOWELL, REBECCA A. BERGSTROM, ROBERT J. MUNROE, JESSICA MASSE, JOHN C. SCHIMENTI
Journal: Genetics Research / Volume 84 / Issue 3 / December 2004
t haplotypes are naturally occurring, variant forms of the t complex on mouse chromosome 17, characterized by the presence of four inversions with respect to wild-type. They harbour mutations causing male sterility, male transmission ratio distortion (TRD) and embryonic lethality. Mice carrying t haplotypes have been found throughout the world, and genetic studies of the lethal mutations have identified at least 16 complementation groups. The embryonic lethal phenotypes of many t haplotypes have been characterized in detail, and are thought to be the consequence of homozygosity for single gene mutations. However, the existence of additional mutations in genes that function at later stages of development would be obscured. Here we investigated the possibility of multiple mutations in t haplotypes by screening the tw73 haplotype for the presence of novel mutations. Since genetic analysis of t haplotype mutations is hindered by recombination suppression due to the inversions, deletion complexes covering the proximal two-thirds of the t complex were used to uncover the presence of any new lethal alleles. This analysis revealed a novel mutation between D17Jcs41 and D17Mit100, causing mice carrying both tw73 and selected deletions to die at birth, prior to feeding. The finding of a new, cryptic lethal mutation in t haplotypes is an indication that these recombinationally isolated chromosomes, which already contain at least one lethal mutation that prevents homozygosity, may serve as sinks for the accumulation of additional recessive mutations.