A STUDY TO INVESTIGATE THE RELIABILITY AND CONSISTENCY OF THE SPORTS TUTOR TENNIS CUBETM VELOCITY, TRAJECTORY AND LANDING POINTS

The purpose of this study was to investigate the reliability and consistency of the Sports Tutor Tennis CubeTM ball launcher. Five identical (mass, diameter) competition standard tennis balls were each launched twenty-five times and flight was assessed using 3D infra red motion analysis. 3D resultant velocity was found to be 18.9 ± 0.89 m/s, landing points had a coefficient of variation in the lateral direction of 8.28% and 18.4% in the vertical direction Trajectory was also projected to estimate ball carry showing ball flight range (horizontal spread) of 14.9 ± 3.71 m. Results showed that whilst the commercially popular tennis ball launcher was stroke specific, it exhibited a level of variability This could be seen to bring variance to tennis players’ practice that they once thought did not occur with the use of tennis ball machines

12.2-GHz methanol maser MMB follow-up catalogue - II. Longitude range 186 to 330 degrees

We present the second portion of a catalogue of 12.2-GHz methanol masers detected towards 6.7-GHz methanol masers observed in the unbiased Methanol Multibeam (MMB) Survey. Using the Parkes radio telescope we have targeted all 207 6.7-GHz methanol masers in the longitude range 186 to 330 degrees for 12.2-GHz counterparts. We report the detection of 83 12.2-GHz methanol masers, and one additional source which we suspect is thermal emission, equating to a detection rate of 40 per cent. Of the 83 maser detections, 39 are reported here for the first time. We discuss source properties, including variability and highlight a number of unusual sources. We present a list of 45 candidates that are likely to harbor methanol masers in the 107.0-GHz transition.Comment: Accepted MNRAS 19 July 201

Non-invasive cytometry of tumours using diffusion MRI, measuring water exchange across the cell membrane with Diffusion Exchange Spectroscopy (DEXSY)

The aim of this thesis was to develop a technique to carry out non- invasive cytometry in tumours using diffusion MRI, by measuring water exchange across the cell membrane. My thesis is built on previous work done to charac- terise tumour micro-structure in-vivo, using Vascular Extracellular and Restricted Diffusion for Cytometry in Tumours (VERDICT) MRI by E. Pangiotaki and S. Walker-Samuel et al. [81], and work on Diffusion Exchange Spectroscopy (DEXSY) by Dr Bernard Siow [93] and P. T. Callaghan who first developed DEXSY as a technique for studying porous media [18]. In particular I aimed to develop DEXSY to measure cell membrane permeability. These advanced diffusion MRI techniques could reduce the need for invasive tissue biopsies, enable earlier di- agnosis and better monitoring of disease progression in cancer, through in-vivo characterisation of tissue micro-structure. These advanced diffusion techniques could also be used to gain a better understanding of barriers to drug delivery in mouse models of cancer. I have developed a biological phantom for validating dif- fusion MRI techniques, and used physical phantoms to demonstrate the accuracy of diffusion measurements made with DEXSY. My computational simulations sug- gest that DEXSY can be used to provide a quantitative indicator of cell membrane permeability, as I observe a monotonic relationship between Diffusion Exchange Index (DEI) and permeability in-silico, for a range of permeabilities greater than the physiological range. The DEXSY data acquired from yeast phantoms con- firm that we can observe diffusion exchange in-vitro with this technique. Further work to evaluate the technique in-vivo suggests that DEXSY is sensitive to dif- fusion exchange and tissue micro-structure in tumours. The work in this thesis demonstrates that DEI could be used as a quantitative indicator of cell membrane permeability, and as a potential imaging biomarker in cancer

12.2-GHz methanol maser MMB follow-up catalogue - I. Longitude range 330 to 10 degrees

We present a catalogue of 12.2-GHz methanol masers detected towards 6.7-GHz methanol masers observed in the unbiased Methanol Multibeam (MMB) survey in the longitude range 330\circ (through 360\circ) to 10\circ. This is the first portion of the catalogue which, when complete, will encompass all of the MMB detections. We report the detection of 184 12.2-GHz sources towards 400 6.7-GHz methanol maser targets, equating to a detection rate of 46 per cent. Of the 184 12.2-GHz detections, 117 are reported here for the first time. We draw attention to a number of 'special' sources, particularly those with emission at 12.2-GHz stronger than their 6.7-GHz counterpart and conclude that these unusual sources are not associated with a specific evolutionary stage.Comment: accepted to MNRAS 21 Dec 201

VLA observations of water masers towards 6.7 GHz methanol maser sources

22 GHz water and 6.7 GHz methanol masers are usually thought as signposts of early stages of high-mass star formation but little is known about their associations and the physical environments they occur in. The aim was to obtain accurate positions and morphologies of the water maser emission and relate them to the methanol maser emission recently mapped with Very Long Baseline Interferometry. A sample of 31 methanol maser sources was searched for 22 GHz water masers using the VLA and observed in the 6.7 GHz methanol maser line with the 32 m Torun dish simultaneously. Water maser clusters were detected towards 27 sites finding 15 new sources. The detection rate of water maser emission associated with methanol sources was as high as 71%. In a large number of objects (18/21) the structure of water maser is well aligned with that of the extended emission at 4.5 $\mu$m confirming the origin of water emission from outflows. The sources with methanol emission with ring-like morphologies, which likely trace a circumstellar disk/torus, either do not show associated water masers or the distribution of water maser spots is orthogonal to the major axis of the ring. The two maser species are generally powered by the same high-mass young stellar object but probe different parts of its environment. The morphology of water and methanol maser emission in a minority of sources is consistent with a scenario that 6.7 GHz methanol masers trace a disc/torus around a protostar while the associated 22 GHz water masers arise in outflows. The majority of sources in which methanol maser emission is associated with the water maser appears to trace outflows. The two types of associations might be related to different evolutionary phases.Comment: accepted by Astronomy & Astrophysic

Using Diffusion-Diffusion Exchange Spectroscopy to observe diffusion exchange in yeast

The permeability of cell membranes varies significantly across both healthy and diseased tissue, and changes in cell membrane permeability can occur during treatment response in tumours. Measurements of cell membrane permeability could therefore be useful for tumour detection and as biomarkers of treatment response in the clinic. As the diffusion of water across the cell membrane is directly dependent on cell membrane permeability, we have investigated the ability of diffusion-diffusion exchange spectroscopy to quantify the diffusion exchange of water in a suspension of yeast, as a first step towards its application in tumours

European VLBI Network imaging of 6.7 GHz methanol masers

Context. Methanol masers at 6.7 GHz are well known tracers of high-mass star-forming regions. However, their origin is still not clearly understood. Aims. We aimed to determine the morphology and velocity structure for a large sample of the maser emission with generally lower peak flux densities than those in previous surveys. Methods. Using the European VLBI Network (EVN) we imaged the remaining sources from a sample of sources that were selected from the unbiased survey using the Torun 32 m dish. In this paper we report the results for 17 targets. Together they form a database of a total of 63 source images with high sensitivity (3σ rms = 15−30 mJy/beam ), milliarcsecond angular resolution (6−10 mas) and very good spectral resolution (0.09 km/s or 0.18 km/s ) for detailed studies. Results. We studied in detail the properties of the maser clouds and calculated the mean and median values of the projected size (17.4 ± 1.2 au and 5.5 au, respectively) as well as the FWHM of the line (0.373 ± 0.011 km/s and 0.315 km/s for the mean and median values, respectively), testing whether it was consistent with Gaussian profile. We also found maser clouds with velocity gradients (71%) that ranged from 0.005 km/s/au to 0.210 km/s/au. We tested the kinematic models to explain the observed structures of the 6.7 GHz emission. There were targets where the morphology supported the scenario of a rotating and expanding disk or a bipolar outflow. Comparing the interferometric and single-dish spectra we found that, typically, 50–70% of the flux was missing. This phenomena is not strongly related to the distance of the source. Conclusions. The EVN imaging reveals that in the complete sample of 63 sources the ring-like morphology appeared in 17% of sources, arcs were seen in a further 8%, and the structures were complex in 46% cases. The ultra-compact (UC) H II regions coincide in position in the sky for 13% of the sources. They are related both to extremely high and low luminosity masers from the sample

Moving frames applied to shell elasticity

Exterior calculus and moving frames are used to describe curved elastic shells. The kinematics follow from the Lie-derivative on forms whereas the dynamics via stress-forms.Comment: 20 pages, 1 figur