Tunable fibre-coupled multiphoton microscopy with a negative curvature fibre

Negative curvature fibre (NCF) guides light in its core by inhibiting the coupling of core and cladding modes. In this work, an NCF was designed and fabricated to transmit ultrashort optical pulses for multiphoton microscopy with low group velocity dispersion (GVD) at 800 nm. Its attenuation was measured to be <0.3 dB m(-1) over the range 600-850 nm and the GVD was -180 ± 70 fs(2)  m(-1) at 800 nm. Using an average fibre output power of ∼20 mW and pulse repetition rate of 80 MHz, the NCF enabled pulses with a duration of <200 fs to be transmitted through a length of 1.5 m of fibre over a tuning range of 180 nm without the need for dispersion compensation. In a 4 m fibre, temporal and spectral pulse widths were maintained to within 10% of low power values up to the maximum fibre output power achievable with the laser system used of 278 mW at 700 nm, 808 mW at 800 nm and 420 mW at 860 nm. When coupled to a multiphoton microscope, it enabled imaging of ex vivo tissue using excitation wavelengths from 740 nm to 860 nm without any need for adjustments to the set-up

Overexpression, purification and crystallization of a choline-binding protein CbpI from Streptococcus pneumoniae

The choline-binding protein CbpI from S. pneumoniae has been purified and crystallized and diffraction data have been collected to 3.5 Å resolution

Oil whirl of flexible rotors

Abstract Not Provided

Politics in Leicestershire, c1677 to c1716

This study has two principal aims. The first is to identify the characteristic features of Leicestershire’s politics at a time of turbulence in English political history and the second to examine the relationship between political activity at a local level and nationally. For the purpose of this study ‘politics’ is defined as the way individuals manoeuvred, intrigued and competed with rivals to maintain their personal position and secure political objectives. The focus therefore is on the way men behaved politically in a variety of formal and informal contexts. Five settings are used to examine this behaviour: the role played by the leading aristocrats and gentry, the appointment of local governors, the established church and non-conformity, parliamentary elections and the borough of Leicester. The opening chapters set the national and local context for the research findings that follow. Inter alia the study looks at the local impact of Charles II and James II’ policies of re-modelling local offices to ensure that the militia, the commission of the peace and the corporation were composed of men who would support royal policy and also at the course of parliamentary elections throughout the four decades with particular reference to those during 1678-81, 1701-2 and 1710-15. These elections show the divisions which existed within the political community, the extent to which they were influenced by differences over religion and the way that they were exploited for partisan advantage. Although focussed on local politics, this study is predicated on the assumption that local politics can only be fully understood when the national context is taken into account