Theoretical aspects of high--Q^2 deep inelastic scattering

We present an overview of the theory of high--Q^2 deep inelastic scattering. We focus in particular on the theoretical uncertainties in the predictions for neutral and charged current cross sections obtained by extrapolating from lower Q^2.Comment: 10 (Latex) pages, including 6 embedded figures, uses epsfig.sty, ioplppt.sty and iopl12.sty; Plenary talk presented at the 3rd UK Phenomenology Workshop on HERA Physics, Durham, September 1998, to be published in the Proceeding

Optical followup of galaxy clusters detected by the South Pole Telescope

The South Pole Telescope (SPT) is a 10 meter telescope operating at mm wavelengths. It has recently completed a three-band survey covering 2500 sq. degrees. One of the survey's main goals is to detect galaxy clusters using Sunyaev-Zeldovich effect and use these clusters for a variety of cosmological and astrophysical studies such as the dark energy equation of state, the primordial non-gaussianity and the evolution of galaxy populations. Since 2005, we have been engaged in a comprehensive optical and near-infrared followup program (at wavelengths between 0.4 and 5 {\mu}m) to image high-significance SPT clusters, to measure their photometric redshifts, and to estimate the contamination rate of the candidate lists. These clusters are then used for various cosmological and astrophysical studies.Comment: For TAUP 2011 proceeding

Photoplethysmography for an independent measure of pulsatile pressure under controlled flow conditions

Noninvasive continuous blood pressure measurements are desirable for patients and clinicians. This work proposes and validates a method for transmural pressure measurement using photoplethysmography (PPG) in an in vitro setup that allows control of pressure and flow conditions. The optimum pulsatile volume measure is obtained by comparing parameters extracted from the photoplethysmographic signal (AC amplitude, normalized pulse volume (NPV) and adjusted pulse volume (APV)). Pulsatile volume can then provide pressure measurements using the exponential pressure-volume (P-V) relationship and validated using the gold standard catheter pressure measurement. Pressure, red (R) and infrared (IR) PPG signals were recorded continuously in two arterial models with different cross-sectional areas (Model 1 and Model 2) utilising a pulsatile pump. Flow rates were controlled by varying pumping frequencies at low and high stroke volumes. The optimum method for estimation of the pulsatile volume is through APV, which had a highly significant correlation (r (2)  =  0.99, p  <  0.001) for Model 1 and (r (2)  =  0.98, p  <  0.001) for Model 2. APV obtained a significantly better fit when compared to NPVIR (r (2)  =  0.73, z  =  25.85, p  <  0.001), NPVR (r (2)  =  0.95, z  =  12.26, p  <  0.001), IRAC (r (2)  =  0.52, z  =  28.29, p  <  0.0001) and RAC (r (2)  =  0.92, z  =  15.27, p  <  0.0001) in Model 1, and when compared to NPVIR (r (2)  =  0.92, z  =  10.23, p  <  0.0001), NPVR (r (2)  =  0.96, z  =  5.08, p  <  0.001) IRAC (r (2)  =  0.63, z  =  22.47, p  <  0.0001) and RAC (r (2)  =  0.92, z  =  17.70, p  <  0.0001) in Model 2. These preliminary findings suggest that APV could be used as a potential non-invasive continuous method of blood pressure measurement at different flow conditions

Resonant Subband Landau Level Coupling in Symmetric Quantum Well

Subband structure and depolarization shifts in an ultra-high mobility GaAs/Al_{0.24}Ga_{0.76}As quantum well are studied using magneto-infrared spectroscopy via resonant subband Landau level coupling. Resonant couplings between the 1st and up to the 4th subbands are identified by well-separated anti-level-crossing split resonance, while the hy-lying subbands were identified by the cyclotron resonance linewidth broadening in the literature. In addition, a forbidden intersubband transition (1st to 3rd) has been observed. With the precise determination of the subband structure, we find that the depolarization shift can be well described by the semiclassical slab plasma model, and the possible origins for the forbidden transition are discussed.Comment: 4 pages, 2 figure

Observation of thundercloud-related gamma rays and neutrons in Tibet

During the 2010 rainy season in Yangbajing (4300 m above sea level) in Tibet, China, a long-duration count enhancement associated with thunderclouds was detected by a solar-neutron telescope and neutron monitors installed at the Yangbajing Comic Ray Observatory. The event, lasting for ∼40  min, was observed on July 22, 2010. The solar-neutron telescope detected significant γ-ray signals with energies >40  MeV in the event. Such a prolonged high-energy event has never been observed in association with thunderclouds, clearly suggesting that electron acceleration lasts for 40 min in thunderclouds. In addition, Monte Carlo simulations showed that >10  MeV γ rays largely contribute to the neutron monitor signals, while >1  keV neutrons produced via a photonuclear reaction contribute relatively less to the signals. This result suggests that enhancements of neutron monitors during thunderstorms are not necessarily clear evidence for neutron production, as previously thought

‘Talent-spotting’ or ‘social magic’? Inequality, cultural sorting and constructions of the ideal graduate in elite professions

Graduate outcomes – including rates of employment and earnings – are marked by persistent inequalities related to social class, as well as gender, ethnicity and institution. Despite national policy agendas related to social mobility and ‘fair access to the professions’, high-status occupations are disproportionately composed of those from socially privileged backgrounds, and evidence suggests that in recent decades many professions have become less socially representative. This article makes an original contribution to sociological studies of inequalities in graduate transitions and elite reproduction through a distinct focus on the ‘pre-hiring’ practices of graduate employers. It does this through a critical analysis of the graduate recruitment material of two popular graduate employers. It shows how, despite espousing commitments to diversity and inclusion, constructions of the ‘ideal’ graduate privilege individuals who can mobilise and embody certain valued capitals. Using Bourdieusian concepts of ‘social magic’ and ‘institutional habitus’, the article argues that more attention must be paid to how graduate employers’ practices constitute tacit processes of social exclusion and thus militate against the achievement of more equitable graduate outcomes and fair access to the ‘top jobs

First Results from Pan-STARRS1: Faint, High Proper Motion White Dwarfs in the Medium-Deep Fields

The Pan-STARRS1 survey has obtained multi-epoch imaging in five bands (Pan-STARRS1 gps, rps, ips, zps, and yps) on twelve "Medium Deep Fields", each of which spans a 3.3 degree circle. For the period between Apr 2009 and Apr 2011 these fields were observed 50-200 times. Using a reduced proper motion diagram, we have extracted a list of 47 white dwarf (WD) candidates whose Pan-STARRS1 astrometry indicates a non-zero proper motion at the 6-sigma level, with a typical 1-sigma proper motion uncertainty of 10 mas/yr. We also used astrometry from SDSS (when available) and USNO-B to assess our proper motion fits. None of the WD candidates exhibits evidence of statistically significant parallaxes, with a typical 1-sigma uncertainty of 8 mas. Twelve of these candidates are known WDs, including the high proper motion (1.7"/yr) WD LHS 291. We confirm three more objects as WDs through optical spectroscopy. Based on the Pan-STARRS1 colors, ten of the stars are likely to be cool WDs with 4170 K Teff 5000 K and cooling ages <9 Gyr. We classify these objects as likely thick disk WDs based on their kinematics. Our current sample represents only a small fraction of the Pan-STARRS1 data. With continued coverage from the Medium Deep Field Survey and the 3pi survey, Pan-STARRS1 should find many more high proper motion WDs that are part of the old thick disk and halo.Comment: 33 pages, 8 figures, submitted to Ap

Ultra-High Energy Cosmic Ray Nuclei from Individual Magnetized Sources

We investigate the dependence of composition, spectrum and angular distributions of ultra-high energy cosmic rays above 10^19 eV from individual sources on their magnetization. We find that, especially for sources within a few megaparsecs from the observer, observable spectra and composition are severely modified if the source is surrounded by fields of ~ 10^-7 Gauss on scales of a few megaparsecs. Low energy particles diffuse over larger distances during their energy loss time. This leads to considerable hardening of the spectrum up to the energy where the loss distance becomes comparable to the source distance. Magnetized sources thus have very important consequences for observations, even if cosmic rays arrive within a few degrees from the source direction. At the same time, details in spectra and chemical composition may be intrinsically unpredictable because they depend on the unknown magnetic field structure. If primaries are predominantly nuclei of atomic mass A accelerated up to a maximum energy E_max with spectra not much softer than E^-2, secondary protons from photo-disintegration can produce a conspicuous peak in the spectrum at energy ~ E_max/A. A related feature appears in the average mass dependence on energy.Comment: 15 pages, 16 ps figures, published version with minor changes, see http://stacks.iop.org/1475-7516/2004/i=08/a=01

"They think we're OK and we know we're not". A qualitative study of asylum seekers' access, knowledge and views to health care in the UK

&lt;i&gt;Background&lt;/i&gt;: The provision of healthcare for asylum seekers is a global issue. Providing appropriate and culturally sensitive services requires us to understand the barriers facing asylum seekers and the facilitators that help them access health care. Here, we report on two linked studies exploring these issues, along with the health care needs and beliefs of asylum seekers living in the UK. &lt;i&gt;Methods&lt;/i&gt;: Two qualitative methods were employed: focus groups facilitated by members of the asylum seeking community and interviews, either one-to-one or in a group, conducted through an interpreter. Analysis was facilitated using the Framework method. &lt;i&gt;Results&lt;/i&gt;: Most asylum seekers were registered with a GP, facilitated for some by an Asylum Support nurse. Many experienced difficulty getting timely appointments with their doctor, especially for self-limiting symptoms that they felt could become more serious, especially in children. Most were positive about the health care they received, although some commented on the lack of continuity. However, there was surprise and disappointment at the length of waiting times both for hospital appointments and when attending accident and emergency departments. Most had attended a dentist, but usually only when there was a clinical need. The provision of interpreters in primary care was generally good, although there was a tension between interpreters translating verbatim and acting as patient advocates. Access to interpreters in other settings, e.g. in-patient hospital stays, was problematic. Barriers included the cost of over-the-counter medication, e.g. children's paracetamol; knowledge of out-of-hours medical care; and access to specialists in secondary care. Most respondents came from countries with no system of primary medical care, which impacted on their expectations of the UK system. &lt;i&gt;Conclusion&lt;/i&gt;: Most asylum seekers were positive about their experiences of health care. However, we have identified issues regarding their understanding of how the UK system works, in particular the role of general practitioners and referral to hospital specialists. The provision of an Asylum Support nurse was clearly a facilitator to accessing primary medical care. Initiatives to increase their awareness and understanding of the UK system would be beneficial. Interpreting services also need to be developed, in particular their role in secondary care and the development of the role of interpreter as patient advocate