Pulsed beams as field probes for precision measurement

We describe a technique for mapping the spatial variation of static electric, static magnetic, and rf magnetic fields using a pulsed atomic or molecular beam. The method is demonstrated using a beam designed to measure the electric dipole moment of the electron. We present maps of the interaction region, showing sensitivity to (i) electric field variation of 1.5 V/cm at 3.3 kV/cm with a spatial resolution of 15 mm; (ii) magnetic field variation of 5 nT with 25 mm resolution; (iii) radio-frequency magnetic field amplitude with 15 mm resolution. This new diagnostic technique is very powerful in the context of high-precision atomic and molecular physics experiments, where pulsed beams have not hitherto found widespread application.Comment: 6 pages, 12 figures. Figures heavily compressed to comply with arxiv's antediluvian file-size polic

Incidence of community-acquired lower respiratory tract infections and pneumonia among older adults in the United Kingdom: a population-based study.

Community-acquired lower respiratory tract infections (LRTI) and pneumonia (CAP) are common causes of morbidity and mortality among those aged ≥65 years; a growing population in many countries. Detailed incidence estimates for these infections among older adults in the United Kingdom (UK) are lacking. We used electronic general practice records from the Clinical Practice Research Data link, linked to Hospital Episode Statistics inpatient data, to estimate incidence of community-acquired LRTI and CAP among UK older adults between April 1997-March 2011, by age, sex, region and deprivation quintile. Levels of antibiotic prescribing were also assessed. LRTI incidence increased with fluctuations over time, was higher in men than women aged ≥70 and increased with age from 92.21 episodes/1000 person-years (65-69 years) to 187.91/1000 (85-89 years). CAP incidence increased more markedly with age, from 2.81 to 21.81 episodes/1000 person-years respectively, and was higher among men. For both infection groups, increases over time were attenuated after age-standardisation, indicating that these rises were largely due to population aging. Rates among those in the most deprived quintile were around 70% higher than the least deprived and were generally higher in the North of England. GP antibiotic prescribing rates were high for LRTI but lower for CAP (mostly due to immediate hospitalisation). This is the first study to provide long-term detailed incidence estimates of community-acquired LRTI and CAP in UK older individuals, taking person-time at risk into account. The summary incidence commonly presented for the ≥65 age group considerably underestimates LRTI/CAP rates, particularly among older individuals within this group. Our methodology and findings are likely to be highly relevant to health planners and researchers in other countries with aging populations

Inequalities in glycemic management in people living with type 2 diabetes mellitus and severe mental illnesses: cohort study from the UK over 10 years

Introduction Using data from a a primary care pay-for-performance scheme targeting quality indicators, the objective of this study was to assess if people living with type 2 diabetes mellitus (T2DM) and severe mental illnesses (SMI) experienced poorer glycemic management compared with people living with T2DM alone, and if observed differences varied by race/ethnicity, deprivation, gender, or exclusion from the scheme. Research design and methods Primary care data from a cohort of 56 770 people with T2DM, including 2272 people with T2DM and SMI, from London (UK), diagnosed between January 17, 2008 and January 16, 2018, were used. Adjusted mean glycated hemoglobin (HbA1c) and HbA1c differences were assessed using multilevel regression models. Results Compared with people with T2DM only, people with T2DM/SMI were more likely to be of an ethnic minority background, excluded from the pay-for-performance scheme and residing in more deprived areas. Across the sample, mean HbA1c was lower in those with T2DM and SMI (mean HbA1c: 58 mmol/mol; 95% CI 57 to 59), compared with people with T2DM only (mean HbA1c: 59 mmol/mol; 95% CI 59 to 60). However, HbA1c levels were greater in Bangladeshi, Indian, Pakistani, and Chinese people compared with the White British reference in the T2DM/SMI group. People with T2DM/SMI who had been excluded from the pay-for-performance scheme, had HbA1c levels which were +7 mmol/mol (95% CI 2 to 11) greater than those with T2DM/SMI not excluded. Irrespective of SMI status, increasing deprivation and male gender were associated with increased HbA1c levels. Conclusions Despite a pay-for-performance scheme to improve quality standards, inequalities in glycemic management in people with T2DM and SMI persist in those excluded from the scheme and by gender, ethnicity, and area-level deprivation

Limits to the Cas A 44^{44}Ti Line Flux and Constraints on the Ejecta Energy and the Compact Source

Two long observations of Cas A supernova remnant were made by the \emph{Rossi X-ray Timing Explorer} in 1996 and 1997 to search for hard X-ray line emission at 67.9 and 78.4 keV from decay of $^{44}$Ti formed during the supernova event. Continuum flux was detected up to 100 keV, but the $^{44}$Ti lines were not detected. The 90% confidence upper limit to the line flux is 3.6$\times10^{-5}$ photons cm$^{-2}$s$^{-1}$. This is consistent with the recent \emph{BeppoSAX} detection and with the \emph{CGRO}/COMPTEL detection of the companion transition line flux for $^{44}$Sc decay. The mean \emph{BeppoSAX}--COMPTEL flux indicates that 1.5$\pm$0.3 $\times10^{-4}$M$_\odot$ of $^{44}$Ti was produced in the supernova explosion. Based upon recent theoretical calculations, and optical observations suggesting a WN Wolf-Rayet progenitor with an initial mass of $\geq$25 M$_\odot$, the observed $^{44}$Ti yield implies that the Cas A supernova ejecta energy was $\sim2\times10^{51}$ ergs, and as a result a neutron star was formed, rather than a black hole. We suggest Cas A is possibly in the early stages of the AXP/SGR scenario in which the push-back disk has yet to form, and when the disk does form, the accretion will increase the luminosity to that of present-day AXP/SGRs and pulsed emission will commence.Comment: 12 pages, 3 tables, 1 figure, accepted for publication in the Astrophysical Journa

Factors affecting metal mobilisation during oxidation of sulphidic, sandy wetland substrates

Most metals accumulate as sulphides under anoxic conditions in wetland substrates, reducing their bioavailability due to the solubility of metal sulphides. However, upon oxidation of these sulphides when the substrate is occasionally oxidised, metals can be released from the solid phase to the pore water or overlaying surface water. This release can be affected by the presence of carbonates, organic matter and clay. We compared changes of Cd, Cu and Zn mobility (CaCl2 extraction) during oxidation of a carbonate-rich and a carbonate-poor sulphidic, sandy wetland substrate. In addition, we studied how clay with low and high cation sorption capacity (bentonite and kaolinite, respectively) and organic matter (peat) can counteract Cd, Cu and Zn release during oxidation of both carbonate-rich and carbonate-poor sulphidic sediments. CaCl2-extractability of Cu, a measure for its availability, is low in both carbonate-poor and carbonate-rich substrates, whereas its variability is high. The availability of Cd and Zn is much higher and increases when peat is supplied to carbonate-poor substrates. A strong reduction of Cd and Zn extractability is observed when clay is added to carbonate-poor substrates. This reduction depends on the clay type. Most observations could be explained taking into account pH differences between treatments, with kaolinite resulting in a lower pH in comparison to bentonite. These pH differences affect the presence and characteristics of dissolved organic carbon and the metal speciation, which in turns affects the interaction of metals with the solid soil phase. In carbonate-rich substrates, Cd and Zn availability is lower and the effects of peat and clay amendment are less clear. The latter can also be attributed to the high pH and lack of pH differences between treatments

Infrared Properties of Cataclysmic Variables from 2MASS: Results from the 2nd Incremental Data Release

Because accretion-generated luminosity dominates the radiated energy of most cataclysmic variables, they have been ``traditionally'' observed primarily at short wavelengths. Infrared observations of cataclysmic variables contribute to the understanding of key system components that are expected to radiate at these wavelengths, such as the cool outer disk, accretion stream, and secondary star. We have compiled the J, H, and Ks photometry of all cataclysmic variables located in the sky coverage of the 2 Micron All Sky Survey (2MASS) 2nd Incremental Data Release. This data comprises 251 systems with reliably identified near-IR counterparts and S/N > 10 photometry in one or more of the three near-IR bands.Comment: 2 pages, including 1 figure. To appear in the proceedings of The Physics of Cataclysmic Variables and Related Objects, Goettingen, Germany. For our followup ApJ paper (in press), also see http://www.ctio.noao.edu/~hoard/research/2mass/index.htm

Is it cheating or learning the craft of writing? Using Turnitin to help students avoid plagiarism

Plagiarism is a growing problem for universities, many of which are turning to software detection for help in detecting and dealing with it. This paper explores issues around plagiarism and reports on a study of the use of Turnitin in a new university. The purpose of the study was to inform the senior management team about the plagiarism policy and the use of Turnitin. The study found that staff and students largely understood the university’s policy and Turnitin’s place within it, and were very supportive of the use of Turnitin in originality checking. Students who had not used Turnitin were generally keen to do so. The recommendation to the senior management team, which was implemented, was that the use of Turnitin for originality checking should be made compulsory where possible - at the time of the study the use of Turnitin was at the discretion of programme directors. A further aim of the study was to contribute to the sector’s body of knowledge. Prevention of plagiarism through education is a theme identified by Badge and Scott (2009) who conclude an area lacking in research is "investigation of the impact of these tools on staff teaching practices". Although a number of recent studies have considered educational use of Turnitin they focus on individual programmes or subject areas rather than institutions as a whole and the relationship with policy

Simonsenia aveniformis sp nov (Bacillariophyceae), molecular phylogeny and systematics of the genus, and a new type of canal raphe system

The genus Simonsenia is reviewed and S. aveniformis described as new for science by light and electron microscopy. The new species originated from estuarine environments in southern Iberia (Atlantic coast) and was isolated into culture. In LM, Simonsenia resembles Nitzschia, with bridges (fibulae) beneath the raphe, which is marginal. It is only electron microscope (EM) examination that reveals the true structure of the raphe system, which consists of a raphe canal raised on a keel (wing), supported by rib like braces (fenestral bars) and tube-like portulae; between the portulae the keel is perforated by open windows (fenestrae). Based on the presence of portulae and a fenestrated keel, Simonsenia has been proposed to be intermediate between Bacillariaceae and Surirellaceae. However, an rbcL phylogeny revealed that Simonsenia belongs firmly in the Bacillariaceae, with which it shares a similar chloroplast arrangement, rather than in the Surirellaceae. Lack of homology between the surirelloid and simonsenioid keels is reflected in subtle differences in the morphology and ontogeny of the portulae and fenestrae. The diversity of Simonsenia has probably been underestimated, particularly in the marine environment.Polish National Science Centre in Cracow within the Maestro program [N 2012/04/A/ST10/00544]; Sciences and Technologies Foundation-FCT (Portugal) [SFRH/BD/62405/2009]info:eu-repo/semantics/publishedVersio

A toy model of the five-dimensional universe with the cosmological constant

A value of the cosmological constant in a toy model of the five-dimensional universe is calculated in such a manner that it remains in agreement with both astronomical observations and the quantum field theory concerning the zero-point fluctuations of the vacuum. The (negative) cosmological constant is equal to the inverse of the Planck length squared, which means that in the toy model the vanishing of the observed value of the cosmological constant is a consequence of the existence of an energy cutoff exactly at the level of the Planck scale. In turn, a model for both a virtual and a real particle-antiparticle pair is proposed which describes properly some energetic properties of both the vacuum fluctuations and created particles, as well as it allows one to calculate the discrete "bare" values of an elementary-particle mass, electric charge and intrinsic angular momentum (spin) at the energy cutoff. The relationships between the discussed model and some phenomena such as the Zitterbewegung and the Unruh-Davies effect are briefly analyzed, too. The proposed model also allows one to derive the Lorentz transformation and the Maxwell equations while considering the properties of the vacuum filled with the sea of virtual particles and their antiparticles. Finally, the existence of a finite value of the vacuum-energy density resulting from the toy model leads us to the formulation of dimensionless Einstein field equations which can be derived from the Lagrangian with a dimensionless (naively renormalized) coupling constant.Comment: 52 pages, 1 figure; a post-final, rewritten version with a number of new remarks and conclusion