3D tomography of cells in micro-channels

We combine confocal imaging, microfluidics and image analysis to record 3D-images of cells in flow. This enables us to recover the full 3D representation of several hundred living cells per minute. Whereas 3D confocal imaging has thus far been limited to steady specimen, we overcome this restriction and present a method to access the 3D shape of moving objects. The key of our principle is a tilted arrangement of the micro-channel with respect to the focal plane of the microscope. This forces cells to traverse the focal plane in an inclined manner. As a consequence, individual layers of passing cells are recorded which can then be assembled to obtain the volumetric representation. The full 3D information allows for a detailed comparisons with theoretical and numerical predictions unfeasible with e.g.\ 2D imaging. Our technique is exemplified by studying flowing red blood cells in a micro-channel reflecting the conditions prevailing in the microvasculature. We observe two very different types of shapes: `croissants' and `slippers'. Additionally, we perform 3D numerical simulations of our experiment to confirm the observations. Since 3D confocal imaging of cells in flow has not yet been realized, we see high potential in the field of flow cytometry where cell classification thus far mostly relies on 1D scattering and fluorescence signals

No Eigenvalue in Finite Quantum Electrodynamics

We re-examine Quantum Electrodynamics (QED) with massless electron as a finite quantum field theory as advocated by Gell-Mann-Low, Baker-Johnson, Adler, Jackiw and others. We analyze the Dyson-Schwinger equation satisfied by the massless electron in finite QED and conclude that the theory admits no nontrivial eigenvalue for the fine structure constant.Comment: 13 pages, Late

Further evidence that singing fosters mental health and wellbeing: The West Kent and Medway project

Purpose Clift and Morrison (2011) report that weekly singing over eight months for people with enduring mental health issues led to clinically important reductions in mental distress. The present study tested the robustness of the earlier findings. Design Four community singing groups for people with mental health issues ran weekly from November 2014 to the end of 2015. Evaluation place over a six-month period using two validated questionnaires: the short Clinical Outcomes in Routine Evaluation questionnaire (CORE-10), and the Warwick Edinburgh Mental Wellbeing Scale (WEMWBS). Findings Twenty-six participants completed baseline and follow-up questionnaires. CORE-10 scores were significantly reduced, and WEMWBS scores significantly increased. Comparisons with the earlier study found a similar pattern of improvements on CORE items that are part of the 'problems' sub-scale in the full CORE questionnaire. There was also evidence from both studies of participants showing clinically important improvements in CORE-10 scores. Research limitations The main limitations of the study are a small sample size, and the lack of a randomised control group. Originality No attempts have been made previously to directly test the transferability of a singing for health model to a new geographical area and evaluate outcomes using the same validated measure

The Kato square root problem on vector bundles with generalised bounded geometry

We consider smooth, complete Riemannian manifolds which are exponentially locally doubling. Under a uniform Ricci curvature bound and a uniform lower bound on injectivity radius, we prove a Kato square root estimate for certain coercive operators over the bundle of finite rank tensors. These results are obtained as a special case of similar estimates on smooth vector bundles satisfying a criterion which we call generalised bounded geometry. We prove this by establishing quadratic estimates for perturbations of Dirac type operators on such bundles under an appropriate set of assumptions.Comment: Slight technical modification of the notion of "GBG constant section" on page 7, and a few technical modifications to Proposition 8.4, 8.6, 8.

Anomalous Chiral Symmetry Breaking above the QCD Phase Transition

We study the anomalous breaking of U_A(1) symmetry just above the QCD phase transition for zero and two flavors of quarks, using a staggered fermion, lattice discretization. The properties of the QCD phase transition are expected to depend on the degree of U_A(1) symmetry breaking in the transition region. For the physical case of two flavors, we carry out extensive simulations on a 16^3 x 4 lattice, measuring a difference in susceptibilities which is sensitive to U_A(1) symmetry and which avoids many of the staggered fermion discretization difficulties. The results suggest that anomalous effects are at or below the 15% level.Comment: 10 pages including 2 figures and 1 tabl

The unitary ability of IQ in the WISC-IV and its computation

Flanagan and Kaufman (2009) use a difference of 23 IQ points between the highest score (Max) and the lowest score (Min) reported by subjects in the 4 Indexes of Verbal Comprehension, Perceptual Reasoning, Working Memory and Processing Speed to define unitarity of IQ in the WISC-IV. Such a difference in scores is considered very rare and the authors therefore conclude that the total IQ scores in these cases cannot be interpreted. Hereby, we want to argue against the choice of this cut-off threshold value by showing that it was based on the wrong standard deviation value when first computed

Patient and provider characteristics associated with communication about opioids: An observational study

Objective Our objective is to examine the relationship of patient and provider characteristics and communication with chronic non-cancer pain and opioid management in primary care. Method We conducted an observational study using audio-recorded primary care appointments (up to 3/patient) and self-reported assessments of primary care providers (PCPs) and patients. We coded visit transcripts for 1) opioid and pain management talk and 2) mental health and opioid safety talk. Results Eight PCPs and 30 patients had complete data for 78 clinic visits. PCPs and patients engaged in more opioid and pain management talk when patients reported greater pain catastrophizing and PCPs reported higher psychosocial orientation. PCPs and patients engaged in talk about mental health and opioid safety when patients reported greater anxiety, higher working alliance with their PCP, and when PCPs reported higher burnout. PCPs’ negative attitudes about opioids were associated with fewer discussions about mental health and opioid safety. Conclusions Our results should facilitate design of interventions that improve communication and, ultimately, pain outcomes for patients. Practice Implications Clinicians can use our results to increase patient engagement in discussions about opioid use and pain management or mental health and safety discussions

Critical State Behaviour in a Low Dimensional Metal Induced by Strong Magnetic Fields

We present the results of magnetotransport and magnetic torque measurements on the alpha-(BEDT-TTF)2KHg(SCN)4 charge-transfer salt within the high magnetic field phase, in magnetic fields extending to 33 T and temperatures as low as 27 mK. While the high magnetic field phase (at fields greater than ~ 23 T) is expected, on theoretical grounds, to be either a modulated charge-density wave phase or a charge/spin-density wave hybrid, the resistivity undergoes a dramatic drop below ~ 3 K within the high magnetic field phase, falling in an approximately exponential fashion at low temperatures, while the magnetic torque exhibits pronounced hysteresis effects. This hysteresis, which occurs over a broad range of fields, is both strongly temperature-dependent and has several of the behavioural characteristics predicted by critical-state models used to describe the pinning of vortices in type II superconductors in strong magnetic fields. Thus, rather than exhibiting the usual behaviour expected for a density wave ground state, both the transport and the magnetic properties of alpha-(BEDT-TTF)2KHg(SCN)4, at high magnetic fields, closely resembles those of a type II superconductor

QCDOC: A 10-teraflops scale computer for lattice QCD

The architecture of a new class of computers, optimized for lattice QCD calculations, is described. An individual node is based on a single integrated circuit containing a PowerPC 32-bit integer processor with a 1 Gflops 64-bit IEEE floating point unit, 4 Mbyte of memory, 8 Gbit/sec nearest-neighbor communications and additional control and diagnostic circuitry. The machine's name, QCDOC, derives from ``QCD On a Chip''.Comment: Lattice 2000 (machines) 8 pages, 4 figure