Tactile thresholds are preserved yet complex sensory function is impaired over the lumbar spine of chronic non-specific low back pain patients. A preliminary investigation

Objectives: To investigate impairments in sensory function in chronic non-specific low back pain patients and the relationship between any impairment and the clinical features of the condition. Design: A cross-sectional case-control study. Setting: Laboratory based study. Participants: Nineteen chronic non-specific low back pain patients and nineteen healthy controls. Main Outcome measures: Tactile threshold, two point discrimination distance and accuracy at a task involving recognizing letters drawn over the skin of the lower back (graphaesthesia) were assessed over the lumbar spine in both groups. Pain duration, pain intensity, physical function, anxiety and depression were assessed by questionnaire in the back pain group Results: We found no difference in tactile threshold between the two groups (median difference 0.00 95% CI -0.04 – 0.04). There was a significant difference between controls and back pain patients for two point discrimination (mean difference 17.85 95% CI 5.93 – 29.77) and graphaesthesia accuracy (mean difference 6.13 95% CI 1.27-10.99). Low back pain patients had a larger lumbar two point discrimination distance threshold and a greater letter recognition error rate. In the patient group, we found no relationship between clinical profile and sensory function and no relationship between the sensory tests. Conclusions: These data support existing findings of perceptual abnormalities in chronic non-specific low back pain patients and are suggestive of cortical rather than peripheral sensory dysfunction. Amelioration of these abnormalities may present a target for therapeutic intervention

Left Atrial scar assessment using imaging with isotropic spatial resolution and compressed sensing

Summary. We assess left atrial scar using late gadolinium enhancement (LGE) with isotropic spatial resolution of $1.4^3 mm^3$ by using highly accelerated LOST [1] reconstruction. Background. Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia [2]. Pulmonary vein isolation (PVI) using radiofrequency (RF)-ablation is the leading treatment for AF. Recently, LGE imaging of the LA has been used to identify atrial wall scar due to RF-ablation [3]. However, current LGE methods have limited spatial resolution that substantially impact assessment of scar in the complex geometry of PVs and LA. In this study, we sought to utilize prospective random k-space sampling and LOST [1] for accelerated LGE imaging, where reduction in imaging time was traded-off for improved isotropic spatial-resolution. Methods. 23 patients with history of AF (6 females, $58.1 \pm 9.6$ years, 9 pre-PVI, 2 with history of PVI; 8 post-PVI; 3 with both pre and post-PVI) were recruited for this study. LGE images were acquired 10-to-20 minutes after bolus infusion of 0.2 mmol/kg Gd-DTPA. Free-breathing ECG-triggered navigator-gated inversion-recovery GRE sequences were used for all acquisitions ($TR/TE/ \alpha = 5.2/2.6ms/25°, FOV=320×320×100mm$). The PV inflow artifact reduction technique in [4] was also utilized. For each patient, a standard non-isotropic 3D LGE scan ($1.4×1.4×4.0mm^3$) and a 3-fold-accelerated highresolution 3D LGE scan ($1.4^3 mm^3$) were performed, with randomized acquisition order. For random undersampling, central k-space (45×35 in ky-kz) was fullysampled, edges randomly discarded, and phase reordering performed as in [5]. Acquisition times were ~4 mins assuming 100% scan-efficiency at 70bpm for both scans. All undersampled data were reconstructed offline using LOST [1]. LOST-reconstructed high-resolution, and standard LGE images were scored by two blinded readers for diagnostic value, presence of LGE(yes/no); and image quality in axial(Ax), coronal(Co) and sagittal (Sa) views (1=poor,4=excellent). Results. Three cases were declared non-diagnostic due to contrast-washout and imperfect inversion-time. LGE was visually present in 14 of the remaining 20 patients based on standard-LGE images, and 12 based on LOST-reconstructed ones (disagreement on one pre- and one postPVI patient). Figure 1 and 2 show comparisons of isotropic vs. non-isotropic LGE images in two patients. Image scores for LOST-LGE: $Ax=2.90 \pm 0.70, Sa=3.33 \pm 0.66, Co=3.00 \pm 0.63$; and standard LGE: $Ax=3.76 \pm 0.54, Sa=2.48 \pm 0.60, Co=2.24 \pm 0.44$, where differences were significant in all views. Conclusions. LOST allows isotropic spatial-resolution in LGE for assessment of LA and PV scar. Isotropic resolution allows reformatting LGE images in any orientation and facilitates assessment of scar. Further clinical study is needed to assess if the improved spatial resolution will impact the diagnostic interpretation of data

WARNING: Physics Envy May Be Hazardous To Your Wealth!

The quantitative aspirations of economists and financial analysts have for many years been based on the belief that it should be possible to build models of economic systems - and financial markets in particular - that are as predictive as those in physics. While this perspective has led to a number of important breakthroughs in economics, "physics envy" has also created a false sense of mathematical precision in some cases. We speculate on the origins of physics envy, and then describe an alternate perspective of economic behavior based on a new taxonomy of uncertainty. We illustrate the relevance of this taxonomy with two concrete examples: the classical harmonic oscillator with some new twists that make physics look more like economics, and a quantitative equity market-neutral strategy. We conclude by offering a new interpretation of tail events, proposing an "uncertainty checklist" with which our taxonomy can be implemented, and considering the role that quants played in the current financial crisis.Comment: v3 adds 2 reference

Determinants of social inequalities in stroke incidence across Europe:a collaborative analysis of 126 635 individuals from 48 cohort studies

Knowledge on the origins of the social gradient in stroke incidence in different populations is limited. This study aims to estimate the burden of educational class inequalities in stroke incidence and to assess the contribution of risk factors in determining these inequalities across Europe

Retrieval of vegetative fluid resistance terms for rigid stems using airborne lidar.

Hydraulic resistance of riparian forests is an unknown but important term in flood conveyance modeling. Lidar has proven to be a very important new data source to physically characterize floodplain vegetation. This research outlines a recent campaign that aims to retrieve vegetation fluid resistance terms from airborne laser scanning to parameterize trunk roughness. Information on crown characteristics and vegetation spacing can be extracted for individual trees to aid in the determining of trunk stem morphology. Airborne lidar data were used to explore the potential to characterize some of the prominent tree morphometric properties from natural and planted riparian poplar zones such as tree position, tree height, trunk location, and tree spacing. Allometric equations of tree characteristics extrapolated from ground measurements were used to infer below-canopy morphometric variables. Results are presented from six riparian-forested zones on the Garonne and Allier rivers in southern and central France. The tree detection and crown segmentation (TDCS) method identified individual trees with 85% accuracy, and the TreeVaW method detected trees with 83% accuracy. Tree heights were overall estimated at both river locations with an RMSE error of around 19% for both methods, but crown diameter at the six sites produced large deviations from ground-measured values of above 40% for both methods. Total height-derived trunk diameters using the TDCS method produced the closest roughness coefficient values to the ground-derived roughness coefficients. The stem roughness values produced from this method fell within guideline values

Clinical characteristics and outcomes of patients with acute myelogenous leukemia admitted to intensive care: a case-control study

<p>Abstract</p> <p>Background</p> <p>There is limited epidemiologic data on patients with acute myelogenous (myeloid) leukemia (AML) requiring life-sustaining therapies in the intensive care unit (ICU). Our objectives were to describe the clinical characteristics and outcomes in critically ill AML patients.</p> <p>Methods</p> <p>This was a retrospective case-control study. Cases were defined as adult patients with a primary diagnosis of AML admitted to ICU at the University of Alberta Hospital between January 1^st2002 and June 30^th2008. Each case was matched by age, sex, and illness severity (ICU only) to two control groups: hospitalized AML controls, and non-AML ICU controls. Data were extracted on demographics, course of hospitalization, and clinical outcomes.</p> <p>Results</p> <p>In total, 45 AML patients with available data were admitted to ICU. Mean (SD) age was 54.8 (13.1) years and 28.9% were female. Primary diagnoses were sepsis (32.6%) and respiratory failure (37.3%). Mean (SD) APACHE II score was 30.3 (10.3), SOFA score 12.6 (4.0) with 62.2% receiving mechanical ventilation, 55.6% vasoactive therapy, and 26.7% renal replacement therapy. Crude in-hospital, 90-day and 1-year mortality was 44.4%, 51.1% and 71.1%, respectively. AML cases had significantly higher adjusted-hazards of death (HR 2.23; 95% CI, 1.38-3.60, p = 0.001) compared to both non-AML ICU controls (HR 1.69; 95% CI, 1.11-2.58, p = 0.02) and hospitalized AML controls (OR 1.0, reference variable). Factors associated with ICU mortality by univariate analysis included older age, AML subtype, higher baseline SOFA score, no change or an increase in early SOFA score, shock, vasoactive therapy and mechanical ventilation. Active chemotherapy in ICU was associated with lower mortality.</p> <p>Conclusions</p> <p>AML patients may represent a minority of all critically ill admissions; however, are not uncommonly supported in ICU. These AML patients are characterized by high illness severity, multi-organ dysfunction, and high treatment intensity and have a higher risk of death when compared with matched hospitalized AML or non-AML ICU controls. The absence of early improvement in organ failure may be a useful predictor for mortality for AML patients admitted to ICU.</p

Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

This paper presents measurements of the $W^+ \rightarrow \mu^+\nu$ and $W^- \rightarrow \mu^-\nu$ cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

Genome-scale constraint-based modeling of Geobacter metallireducens

Background: Geobacter metallireducens was the first organism that can be grown in pure culture to completely oxidize organic compounds with Fe(III) oxide serving as electron acceptor. Geobacter species, including G. sulfurreducens and G. metallireducens, are used for bioremediation and electricity generation from waste organic matter and renewable biomass. The constraint-based modeling approach enables the development of genome-scale in silico models that can predict the behavior of complex biological systems and their responses to the environments. Such a modeling approach was applied to provide physiological and ecological insights on the metabolism of G. metallireducens. Results: The genome-scale metabolic model of G. metallireducens was constructed to include 747 genes and 697 reactions. Compared to the G. sulfurreducens model, the G. metallireducens metabolic model contains 118 unique reactions that reflect many of G. metallireducens\u27 specific metabolic capabilities. Detailed examination of the G. metallireducens model suggests that its central metabolism contains several energy-inefficient reactions that are not present in the G. sulfurreducens model. Experimental biomass yield of G. metallireducens growing on pyruvate was lower than the predicted optimal biomass yield. Microarray data of G. metallireducens growing with benzoate and acetate indicated that genes encoding these energy-inefficient reactions were up-regulated by benzoate. These results suggested that the energy-inefficient reactions were likely turned off during G. metallireducens growth with acetate for optimal biomass yield, but were up-regulated during growth with complex electron donors such as benzoate for rapid energy generation. Furthermore, several computational modeling approaches were applied to accelerate G. metallireducens research. For example, growth of G. metallireducens with different electron donors and electron acceptors were studied using the genome-scale metabolic model, which provided a fast and cost-effective way to understand the metabolism of G. metallireducens. Conclusion: We have developed a genome-scale metabolic model for G. metallireducens that features both metabolic similarities and differences to the published model for its close relative, G. sulfurreducens. Together these metabolic models provide an important resource for improving strategies on bioremediation and bioenergy generation