"Production of resonances by pions"

This thesis contains a description of investigations that have been undertaken to examine the inelastic interactions of positively charged pi-mesons with protons. The experiment was carried out at the European Centre for Nuclear Research in Geneva using a separated beam of 5 GeV/c pions produced by the 27 GeV Proton Synchrotron. Pictures were taken of the interactions of the pions with the protons of the 150 cm. British National Hydrogen Bubble Chamber. To analyse the interactions recorded on the films of the chamber a digitized measuring apparatus was constructed. The machine provided data about the interactions encoded in a suitable manner for automatic processing. The numerical and statistical methods used in the computation of the most probable dynamical interpretation of each interaction are given. In the sample of these high multiplicity interactions that have six or seven particles in the final state of the reaction, evidence was found for the production of intermediate particles or resonances. The statistical analysis carried out was consistent with a large production of the well-known resonances N*3/2,pº,wº which decay into two or three particles. Apart from a small number of Xº particles, no evidence was found for a large production of any other resonances including those of which the N*3/2,pº, and wº constitute one of the decay products. The production of resonances in high multiplicity interactions therefore does not proceed by the quasi two-body mode which has been shown to be a dominant feature of the lower multiplicity interaction. It was found that the mechanism of resonance production in k, 5 and 6 body intermediate states could not be described adequately by the statistical model. The distributions of dynamical parameters showed similar effects to those observed for the peripheral production of resonance in the quasi two-body mode of lower multiplicity interactions. It was found that the mechanism of resonance production in 4, 5 and 6 body intermediate states could not be described adequately by the statistical model. The distributions of dynamical parameters showed similar effects to those observed for the peripheral production of resonance in the quasi two-body mode of lower multiplicity interactions

The Effect of Bilingualism On Intelligence At The High School Level

The purpose of this study is to determine the effect of bilingualism on intelligence at the high school level

Is communications a strategic activity in UK Education?

This qualitative exploratory paper investigates whether communications/public relations is regarded by opinion formers in UK education as a strategic business activity or a tactical marketing tool. It is based upon depth interviews with 16 senior managers with strategic roles in UK higher or further education, or Government bodies, conducted between June and September 2004. The findings seem to suggest that communications/PR is ideally seen by leaders as a strategic function, but that there are limitations to this vision becoming a reality. The research goes on to offer initial conclusions on some of the issues surrounding perception, resource, and implementation of strategic communications/PR in UK education, with implications for practitioners considered

Particle size distributions and the vertical distribution of suspended matter in the upwelling region off Oregon

Various methods of presenting and mathematically describing particle size distribution are explained and evaluated. The hyperbolic distribution is found to be the most practical but the more complex characteristic vector analysis is the most sensitive to changes in the shape of the particle size distributions. A method for determining onshore-offshore flow patterns from the distribution of particulates was presented. A numerical model of the vertical structure of two size classes of particles was developed. The results show a close similarity to the observed distributions but overestimate the particle concentration by forty percent. This was attributed to ignoring grazing by zooplankton. Sensivity analyses showed the size preference was most responsive to the maximum specific growth rates and nutrient half saturation constants. The verical structure was highly dependent on the eddy diffusivity followed closely by the growth terms

Scalable multimodal convolutional networks for brain tumour segmentation

Brain tumour segmentation plays a key role in computer-assisted surgery. Deep neural networks have increased the accuracy of automatic segmentation significantly, however these models tend to generalise poorly to different imaging modalities than those for which they have been designed, thereby limiting their applications. For example, a network architecture initially designed for brain parcellation of monomodal T1 MRI can not be easily translated into an efficient tumour segmentation network that jointly utilises T1, T1c, Flair and T2 MRI. To tackle this, we propose a novel scalable multimodal deep learning architecture using new nested structures that explicitly leverage deep features within or across modalities. This aims at making the early layers of the architecture structured and sparse so that the final architecture becomes scalable to the number of modalities. We evaluate the scalable architecture for brain tumour segmentation and give evidence of its regularisation effect compared to the conventional concatenation approach.Comment: Paper accepted at MICCAI 201

Quantifying errors due to frequency changes and target location uncertainty for radar refractivity retrievals

Radar refractivity retrievals can capture near-surface humidity changes, but noisy phase changes of the ground clutter returns limit the accuracy for both klystron- and magnetron-based systems. Observations with a C-band (5.6 cm) magnetron weather radar indicate that the correction for phase changes introduced by local oscillator frequency changes leads to refractivity errors no larger than 0.25 N units: equivalent to a relative humidity change of only 0.25% at 20°C. Requested stable local oscillator (STALO) frequency changes were accurate to 0.002 ppm based on laboratory measurements. More serious are the random phase change errors introduced when targets are not at the range-gate center and there are changes in the transmitter frequency (ΔfTx) or the refractivity (ΔN). Observations at C band with a 2-μs pulse show an additional 66° of phase change noise for a ΔfTx of 190 kHz (34 ppm); this allows the effect due to ΔN to be predicted. Even at S band with klystron transmitters, significant phase change noise should occur when a large ΔN develops relative to the reference period [e.g., ~55° when ΔN = 60 for the Next Generation Weather Radar (NEXRAD) radars]. At shorter wavelengths (e.g., C and X band) and with magnetron transmitters in particular, refractivity retrievals relative to an earlier reference period are even more difficult, and operational retrievals may be restricted to changes over shorter (e.g., hourly) periods of time. Target location errors can be reduced by using a shorter pulse or identified by a new technique making alternate measurements at two closely spaced frequencies, which could even be achieved with a dual–pulse repetition frequency (PRF) operation of a magnetron transmitter

Aquaporins in GtoPdb v.2021.3

Aquaporins and aquaglyceroporins are membrane channels that allow the permeation of water and certain other small solutes across the cell membrane, or in the case of AQP6, AQP11 and AQP12A, intracellular membranes, such as vesicles and the endoplasmic reticulum membrane [16]. Since the isolation and cloning of the first aquaporin (AQP1) [20], 12 additional mammalian members of the family have been identified, although little is known about the functional properties of one of these (AQP12A; Q8IXF9) and it is thus not tabulated. The other 12 aquaporins can be broadly divided into three families: orthodox aquaporins (AQP0,-1,-2,-4,-5, -6 and -8) permeable mainly to water, but for some additional solutes [4]; aquaglyceroporins (AQP3,-7 -9 and -10), additionally permeable to glycerol and for some isoforms urea [14], and superaquaporins (AQP11 and 12) located within cells [12]. Some aquaporins also conduct ammonia and/or H2O2 giving rise to the terms 'ammoniaporins' ('aquaammoniaporins') and 'peroxiporins', respectively. Aquaporins are impermeable to protons and other inorganic and organic cations, with the possible exception of AQP1, although this is controversial [14]. One or more members of this family of proteins have been found to be expressed in almost all tissues of the body [reviewed in Yang (2017) [26]]. AQPs are involved in numerous processes that include systemic water homeostasis, adipocyte metabolism, brain oedema, cell migration and fluid secretion by epithelia. Loss of function mutations of some human AQPs, or their disruption by autoantibodies further underscore their importance [reviewed by Verkman et al. (2014) [23], Kitchen et al. (2105) [14]]. Functional AQPs exist as homotetramers that are the water conducting units wherein individual AQP subunits (each a protomer) have six TM helices and two half helices that constitute a seventh 'pseudotransmembrane domain' that surrounds a narrow water conducting channel [16]. In addition to the four pores contributed by the protomers, an additional hydrophobic pore exists within the center of the complex [16] that may mediate the transport through AQP1. Although numerous small molecule inhibitors of aquaporins, particularly APQ1, have been reported primarily from Xenopus oocyte swelling assays, the activity of most has subsequently been disputed upon retesting using assays of water transport that are less prone to various artifacts [5] and they are therefore excluded from the tables [see Tradtrantip et al. (2017) [22] for a review]