Investigation of charge coupled device correlation techniques

Analog Charge Transfer Devices (CTD's) offer unique advantages to signal processing systems, which often have large development costs, making it desirable to define those devices which can be developed for general system's use. Such devices are best identified and developed early to give system's designers some interchangeable subsystem blocks, not requiring additional individual development for each new signal processing system. The objective of this work is to describe a discrete analog signal processing device with a reasonably broad system use and to implement its design, fabrication, and testing

Cosmological Implications of the Tetron Model of Elementary Particles

Based on a possible solution to the tetron spin problem, a modification of the standard Big Bang scenario is suggested, where the advent of a spacetime manifold is connected to the appearance of tetronic bound states. The metric tensor is constructed from tetron constituents and the reason for cosmic inflation is elucidated. Furthermore, there are natural dark matter candidates in the tetron model. The ratio of ordinary to dark matter in the universe is calculated to be 1:5.Comment: 23 page

Transverse Momentum in Semi-Inclusive Polarized Deep Inelastic Scattering and the Spin-Flavor Structure of the Proton

The non-valence spin-flavor structure of the nucleon extracted from semi-inclusive measurements of polarized deep inelastic scattering depends strongly on the transverse momentum of the detected hadrons which are used to determine the individual polarized sea distributions. This physics may explain the recent HERMES observation of a positively polarized strange sea through semi-inclusive scattering, in contrast to the negative strange sea polarization deduced from inclusive polarized deep inelastic scattering.Comment: 4 pages, revtex style, 2 figure

Changes in chemsex and sexual behaviour over time, among a cohort of MSM in London and Brighton: Findings from the AURAH2 study.

BACKGROUND: Recent evidence has suggested that chemsex (the use of mephedrone, crystal methamphetamine and γ -hydroxybutyrate/ γ -butryolactone (GHB/GBL) to enable, enhance and prolong sexual interactions) has increased among men having sex with men (MSM) attending sexual health clinics in large UK cities. To date there has been no data from the UK or Europe that describes changes in chemsex over time within a cohort of MSM. METHODS: The prospective cohort study, Attitudes to and Understanding Risk of Acquisition of HIV over Time (AURAH2), collected online questionnaire data from HIV negative or undiagnosed MSM (at enrolment) from 2015 to 2018, recruited from sexual health clinics. We aim to investigate changes in chemsex, three individual drugs associated with chemsex, frequency of chemsex sessions and measures of sexual behaviour, among the cohort of MSM over the study's 3 year follow-up period. RESULTS: In total 622 MSM completed at least one online questionnaire for the AURAH2 study, of which 400 (64.3%) were still engaged with the study within the last six months of follow-up. Prevalence of chemsex significantly declined during the follow-up from 31.8% (198/622) at the first online questionnaire, to 11.1% (8/72; p < 0.001) at the 9th. This decline was reflected in the proportion of MSM reporting use of two of the three individual chemsex drugs: mephedrone use had significantly declined from 25.2% at the first online questionnaire to 9.7% (p < 0.001) at the 9th, GHB/GBL use had also declined from 19.9% to 8.3% (p = 0.001). While crystal methamphetamine use declined, but not significantly (11.1%-6.9% [p = 0.289]). Most measures of sexual behaviour (any anal sex, group sex, recent HIV test and bacterial STI) also tended to decline over the follow-up period, with the exception of CLAI with more than one and more than two partners. CONCLUSIONS: Chemsex and use of two individual chemsex drugs (mephedrone and GHB/GBL) significantly declined over time among individuals in the study, alongside most measures of sexual behaviour with the exception of those related to CLAI. Focusing health promotion and HIV prevention, such as awareness of post-exposure prophylaxis (PEP) and access to pre-exposure prophylaxis (PrEP), on MSM that report chemsex, and in particular problematic chemsex, would be highly beneficial, potentially only necessary for a relatively short period of time for individuals, and could have long term benefits for HIV and STI prevention

Radio-frequency discharges in Oxygen. Part 1: Modeling

In this series of three papers we present results from a combined experimental and theoretical effort to quantitatively describe capacitively coupled radio-frequency discharges in oxygen. The particle-in-cell Monte-Carlo model on which the theoretical description is based will be described in the present paper. It treats space charge fields and transport processes on an equal footing with the most important plasma-chemical reactions. For given external voltage and pressure, the model determines the electric potential within the discharge and the distribution functions for electrons, negatively charged atomic oxygen, and positively charged molecular oxygen. Previously used scattering and reaction cross section data are critically assessed and in some cases modified. To validate our model, we compare the densities in the bulk of the discharge with experimental data and find good agreement, indicating that essential aspects of an oxygen discharge are captured.Comment: 11 pages, 10 figure

Polarized semi-inclusive electroweak structure functions at next-to-leading-order

We present a next-to-leading order (NLO) computation of the full set of polarized and unpolarized electroweak semi-inclusive DIS (SIDIS) structure functions, whose knowledge is crucial for a precise extraction of polarized parton distributions. We focus on the phenomenology of the polarized structure functions for the kinematical conditions that could be reached in an Electron-Ion-Collider. We show that the NLO corrections are sizeable, particularly in the small-$x$ range. We test the sensitivity of these structure functions on certain quark distributions and compare it to the situation of inclusive DIS and electromagnetic SIDIS.Comment: 17 pages, 5 figure

A study of patent thickets

Report analysing whether entry of UK enterprises into patenting in a technology area is affected by patent thickets in the technology area

Changes in recreational drug use, drug use associated with chemsex, and HIV-related behaviours, among HIV-negative men who have sex with men in London and Brighton, 2013-2016.

OBJECTIVES: The objective of this study was to compare the prevalence of polydrug use, use of drugs associated with chemsex, specific drug use, and HIV-related behaviours, between two time periods , using two groups of HIV-negative men who have sex with men (MSM) attending the same sexual health clinics in London and Brighton, in two consecutive periods of time from 2013 to 2016. METHODS: Data from MSM in the cross-sectional Attitudes to and Understanding Risk of Acquisition of HIV (AURAH) study (June 2013 to September 2014) were compared with baseline data from different MSM in the prospective cohort study Attitudes to and Understanding Risk of Acquisition of HIV over Time (AURAH2) (November 2014 to April 2016). Prevalence of polydrug use, drug use associated with chemsex and specific drug use, and 10 measures of HIV-related behaviours including condomless sex, post-exposure prophylaxis (PEP) use, pre-exposure prophylaxis (PrEP) use, and HIV testing, were compared. Prevalence ratios (PRs) for the association of the study (time period) with drug use and HIV-related behaviour measures were estimated using modified Poisson regression analysis, unadjusted and adjusted for sociodemographic factors. RESULTS: In total, 991 MSM were included from AURAH and 1031 MSM from AURAH2. After adjustment for sociodemographic factors, use of drugs associated with chemsex had increased (adjusted PR (aPR) 1.30, 95% CI 1.11 to 1.53) and there were prominent increases in specific drug use; in particular, mephedrone (aPR 1.32, 95% CI 1.10 to 1.57), γ-hydroxybutyric/γ-butryolactone (aPR 1.47, 95% CI 1.15 to 1.87) and methamphetamine (aPR 1.42, 95% CI 1.01 to 2.01). Use of ketamine had decreased (aPR 0.54, 95% CI 0.38 to 0.78). Certain measures of HIV-related behaviours had also increased, most notably PEP use (aPR 1.50, 95% CI 1.21 to 1.88) and number of self-reported bacterial STI diagnoses (aPR 1.24, 95% CI 1.08 to 1.43). CONCLUSIONS: There have been significant increases in drug use associated with chemsex and some measures of HIV-related behaviours among HIV-negative MSM in the last few years. Changing patterns of drug use and associated behaviours should be monitored to enable sexual health services to plan for the increasingly complex needs of some clients

Next-to-Leading Order QCD Corrections to Jet Cross Sections and Jet Rates in Deeply Inelastic Electron Proton Scattering

Jet cross sections in deeply inelastic scattering in the case of transverse photon exchange for the production of (1+1) and (2+1) jets are calculated in next-to-leading order QCD (here the `+1' stands for the target remnant jet, which is included in the jet definition for reasons that will become clear in the main text). The jet definition scheme is based on a modified JADE cluster algorithm. The calculation of the (2+1) jet cross section is described in detail. Results for the virtual corrections as well as for the real initial- and final state corrections are given explicitly. Numerical results are stated for jet cross sections as well as for the ratio \sigma_{\mbox{\small (2+1) jet}}/\sigma_{\mbox{\small tot}} that can be expected at E665 and HERA. Furthermore the scale ambiguity of the calculated jet cross sections is studied and different parton density parametrizations are compared.Comment: 40 pages, LBL-34147 (Latex file). (figures available by mail on request (send e-mail to [email protected]), please include your address such that it can be used as an address label

Attitudes to and Understanding of Risk of Acquisition of HIV Over Time: Design and Methods for an Internet-based Prospective Cohort Study Among UK Men Who Have Sex With Men (the AURAH2 Study)

Background: The annual number of new HIV infections among men who have sex with men (MSM) has risen in the UK and, of those HIV positive, the proportion undiagnosed is high. The prospective AURAH2 study aims to assess factors associated with HIV acquisition among MSM in the UK, and to investigate changes over time within individuals in sexual behaviour and HIV-testing practices. / Methods/Design: AURAH2 is a prospective study among MSM without diagnosed HIV, aiming to recruit up to 1000 sexually active MSM attending sexual health clinics in London and Brighton. Participants complete an initial paper-based questionnaire, followed by four monthly online follow-up questionnaires collecting socio-demographic, health and behavioural data, including sexual behaviour, recreational and other drug use, HIV testing practices and Pre-Exposure Prophylaxis use, over a planned three year period. / Discussion: The results from AURAH2 study will provide an important insight into established and emerging risk behaviours that may be associated with acquisition of HIV in MSM, in the UK, changes over time within individuals in sexual behaviour, and inform on HIV testing practices. This data will be crucial to inform future HIV prevention strategies