Signal specific electric potential sensors for operation in noisy environments

Limitations on the performance of electric potential sensors are due to saturation caused by environmental electromagnetic noise. The work described involves tailoring the response of the sensors to reject the main components of the noise, thereby enhancing both the effective dynamic range and signal to noise. We show that by using real-time analogue signal processing it is possible to detect a human heartbeat at a distance of 40 cm from the front of a subject in an unshielded laboratory. This result has significant implications both for security sensing and biometric measurements in addition to the more obvious safety related applications

The Cryogenic Refractive Indices of S-FTM16, a Unique Optical Glass for Near-Infrared Instruments

The Ohara glass S-FTM16 is of considerable interest for near-infrared optical designs because it transmits well through the K band and because negative S-FTM16 elements can be used to accurately achromatize positive calcium fluoride elements in refractive collimators and cameras. Glass manufacturers have sophisticated equipment to measure the refractive index at room temperature, but cannot typically measure the refractive index at cryogenic temperatures. Near-infrared optics, however, are operated at cryogenic temperatures to reduce thermal background. Thus we need to know the temperature dependence of S-FTM16's refractive index. We report here our measurements of the thermal dependence of S-FTM16's refractive index between room temperature and ~77 K. Within our measurement errors we find no evidence for a wavelength dependence or a nonlinear temperature term so our series of measurements can be reduced to a single number. We find that Delta n_{abs} / Delta T = -2.4x10^{-6} K^{-1} between 298 K and ~77 K and in the wavelength range 0.6 micron to 2.6 micron. We estimate that the systematic error (which dominates the measurement error) in our measurement is 10%, sufficiently low for most purposes. We also find the integrated linear thermal expansion of S-FTM16 between 298 K and 77 K is -0.00167 m m^{-1}.Comment: 8 pages, including 9 figures. Uses emulateapj.cls. Accepted for publication in PAS

Body mass index, waist circumference, waist-hip ratio, and glucose intolerance in Chinese and Europid adults in Newcastle, UK.

OBJECTIVE: To compare the prevalence of glucose intolerance (impaired glucose tolerance and diabetes), and its relationship to body mass index (BMI) and waist-hip ratio in Chinese and Europid adults. DESIGN: This was a cross sectional study. SETTING: Newcastle upon Tyne. SUBJECTS: These comprised Chinese and Europid men and women, aged 25-64 years, and resident in Newcastle upon Tyne, UK. MAIN OUTCOME MEASURES: Two hour post load plasma glucose concentration, BMI, waist circumference, and waist-hip ratio. METHODS: Population based samples of Chinese and European adults were recruited. Each subject had a standard WHO oral glucose tolerance test. RESULTS: Complete data were available for 375 Chinese and 610 Europid subjects. The age adjusted prevalences of glucose intolerance in Chinese and Europid men were 13.0% (p = 0.04). Mean BMIs were lower in Chinese men (23.8 v 26.1) and women (23.5 v 26.1) than in the Europids (p values < 0.001), as were waist circumferences (men, 83.3 cm v 90.8, p < 0.001; women, 77.3 cm v 79.2, p < 0.05). Mean waist-hip ratios were lower in Chinese men (0.90 v 0.91, p = 0.02) but higher in Chinese women (0.84 v 0.78, p < 0.001) compared with Europids. In both Chinese and Europid adults, higher BMI, waist circumference, and waist-hip ratio were associated with glucose intolerance. CONCLUSIONS: The prevalence of glucose intolerance in Chinese men and women, despite lower BMIs, is similar to or higher than that in local Europid men and women and intermediate between levels found in China and those in Mauritius. It is suggested that an increase in mean BMI to the levels in the Europid population will be associated with a substantial increase in glucose intolerance in Chinese people

Variation in education doctoral students’ conceptions of university teaching

The development of doctoral students as university teachers has received substantially less attention compared with their development as researchers, with a similar deficit extending to research on how they experience and understand university teaching. This article reports the results of a phenomenographic study of education doctoral students’ conceptions of teaching in higher education. Using samples from two education departments in England and Sweden, we conducted interviews to identify variation in doctoral students’ experiences of university teaching. Analysis of the transcripts produced six qualitatively different conceptions of teaching: doctoral students conceptualised university teaching as a means of (A) transmitting knowledge, (B) presenting contrasting concepts of education, (C) communicating and engaging with students, (D) enabling students to apply knowledge and skills, (E) enabling students to interpret and compare concepts of education, and (F) promoting personal, professional and societal development and change. While in broad agreement with previous studies on university teachers’ conceptions of teaching, the study offers a unique insight into how the subject of education is understood by doctoral students who teach. The findings also underline the need to introduce common frameworks of academic development for academics and doctoral students alike that prioritise ways of representing and engaging with the structure of the subject, rather than the acquisition of teaching skills

Homogeneous nucleation of colloidal melts under the influence of shearing fields

We study the effect of shear flow on homogeneous crystal nucleation, using Brownian Dynamics simulations in combination with an umbrella sampling like technique. The symmetry breaking due to shear results in anisotropic radial distribution functions. The homogeneous shear rate suppresses crystal nucleation and leads to an increase of the size of the critical nucleus. These observations can be described by a simple, phenomenological extension of classical nucleation theory. In addition, we find that nuclei have a preferential orientation with respect to the direction of shear. On average the longest dimension of a nucleus is along the vorticity direction, while the shortest dimension is preferably perpendicular to that and slightly tilted with respect to the gradient direction.Comment: 10 pages, 8 figures, Submitted to J. Phys.: Condens. Matte

Energy Down Conversion between Classical Electromagnetic Fields via a Quantum Mechanical SQUID Ring

We consider the interaction of a quantum mechanical SQUID ring with a classical resonator (a parallel $LC$ tank circuit). In our model we assume that the evolution of the ring maintains its quantum mechanical nature, even though the circuit to which it is coupled is treated classically. We show that when the SQUID ring is driven by a classical monochromatic microwave source, energy can be transferred between this input and the tank circuit, even when the frequency ratio between them is very large. Essentially, these calculations deal with the coupling between a single macroscopic quantum object (the SQUID ring) and a classical circuit measurement device where due account is taken of the non-perturbative behaviour of the ring and the concomitant non-linear interaction of the ring with this device.Comment: 7 pages, 6 figure

Nonergodicity transitions in colloidal suspensions with attractive interactions

The colloidal gel and glass transitions are investigated using the idealized mode coupling theory (MCT) for model systems characterized by short-range attractive interactions. Results are presented for the adhesive hard sphere and hard core attractive Yukawa systems. According to MCT, the former system shows a critical glass transition concentration that increases significantly with introduction of a weak attraction. For the latter attractive Yukawa system, MCT predicts low temperature nonergodic states that extend to the critical and subcritical region. Several features of the MCT nonergodicity transition in this system agree qualitatively with experimental observations on the colloidal gel transition, suggesting that the gel transition is caused by a low temperature extension of the glass transition. The range of the attraction is shown to govern the way the glass transition line traverses the phase diagram relative to the critical point, analogous to findings for the fluid-solid freezing transition.Comment: 11 pages, 7 figures; to be published in Phys. Rev. E (1 May 1999

A population-based analysis of germline BAP1 mutations in melanoma

Germline mutation of the BRCA1 associated protein-1 (BAP1) gene has been linked to uveal melanoma, mesothelioma, meningioma, renal cell carcinoma and basal cell carcinoma. Germline variants have also been found in familial cutaneous melanoma pedigrees, but their contribution to sporadic melanoma has not been fully assessed. We sequenced BAP1 in 1,977 melanoma cases and 754 controls and used deubiquitinase assays, a pedigree analysis, and a histopathological review to assess the consequences of the mutations found. Sequencing revealed 30 BAP1 variants in total, of which 27 were rare (ExAc allele frequency <0.002). Of the 27 rare variants, 22 were present in cases (18 missense, one splice acceptor, one frameshift and two near splice regions) and 5 in controls (all missense). A missense change (S98R) in a case that completely abolished BAP1 deubiquitinase activity was identified. Analysis of cancers in the pedigree of the proband carrying the S98R variant and in two other pedigrees carrying clear loss-of-function alleles showed the presence of BAP1-associated cancers such as renal cell carcinoma, mesothelioma and meningioma, but not uveal melanoma. Two of these three probands carrying BAP1 loss-of-function variants also had melanomas with histopathological features suggestive of a germline BAP1 mutation. The remaining cases with germline mutations, which were predominantly missense mutations, were associated with less typical pedigrees and tumours lacking a characteristic BAP1-associated histopathological appearances, but may still represent less penetrant variants. Germline BAP1 alleles defined as loss-of-function or predicted to be deleterious/damaging are rare in melanoma

Correct Social Usage Volume 1: A Course of Instruction in Good Form Style and Deportment by Eighteen Distinguished Authors

The preface of the volume says that, This course of instruction sums up for its readers the substance of the truest good form. It teaches society\u27s customs intelligently, it treats society topics thoroughly, it offers helps for social perplexities. In the scope of its subject matter it includes everything which could rightly be placed between the covers of a practical work on etiquette, while in the unique manner of presenting this matter it has accomplished something never attempted before. This volume is organized into three books: Social Self-Culture, Everyday Etiquette, and Conventional Requirements, each with several essays by an individual author. The book about Social Self-Culture provides general discussion of good manners and etiquette in society. Everyday Etiquette gives more specific advice for various social occasions, such as conversation, table etiquette, correspondence and gifts. Conventional Requirements provides guidelines for such social situations as introductions, calls, and visiting cards.https://openworks.wooster.edu/motherhomeheaven/1091/thumbnail.jp