Gait Extraction and Description by Evidence-Gathering

Using gait as a biometric is of increasing interest, yet there are few model-based, parametric, approaches to extract and describe moving articulated objects. One new approach can detect moving parametric objects by evidence gathering, hence accruing known performance advantages in terms of performance and occlusion. Here we show how that the new technique can be extended not only to extract a moving person, but also to extract and concurrently provide a gait signature for use as a biometric. We show the natural relationship between the bases of these approaches, and the results they can provide. As such, these techniques allow for gait extraction and description for recognition purposes, and with known performance advantages of a well-established vision technique

Understanding and Applying Ecological Principles in Cities

Renaturing cities requires a thorough understanding of how plants and animals interact with the urban environment and humans. But cities are a challenging environment for ecologists to work in, with high levels of heterogeneity and rapid rates of change. In addition, the hostile conditions often found in cities mean that each city, and region of a city, can have their own unique geographical context. In this chapter, we contrast urban ecological research in the UK and Brazil, to demonstrate the challenges and approaches needed to renature cities. In so doing, we provide a platform for global transferability of these locally contextualised approaches. The UK has a long history of urbanisation and, as a result of increasing extinction debts over 200 years, well-established urban ecological research. Research is generally focused on encouraging species back into the city. In contrast, Brazil is a biodiversity hotspot with relatively rich urban flora and fauna. This rich ecosystem is imperilled by current rapid urbanisation and lack of support for urban nature by city-dwellers. By working together and transferring expertise, UK and Brazilian researchers stand a better chance of understanding urban ecological processes and unlocking renaturing processes in each location. We present one such method for applying ecological knowledge to cities, so-called Ecological Engineering, in particular by discussing ecomimicry—the adaptive approach needed to apply global ecological principles to local urban challenges. By reading the ecological landscape in which urban developments sit and applying tailored green infrastructure solutions to new developments and greenspaces, cities may be able to reduce the rate at which extinction debt is accumulated

Physiological responses to moderate intensity continuous and high-intensity interval exercise in persons with paraplegia

Randomized crossover. To test differences in the duration and magnitude of physiological response to isocaloric moderate intensity continuous (MICE) and high-intensity interval exercise (HIIE) sessions in persons with spinal cord injury (SCI). Academic medical center in Miami, FL, USA. Ten adult men (mean ± s.d.; 39 ± 10 year old) with chronic (13.2 ± 8.8 year) paraplegia (T2-T10) completed a graded exercise test. Then, in a randomized order, participants completed MICE and HIIE for a cost of 120 kcal. MICE was performed at 24.6% PO . During HIIE, exercise was completed in 2 min work and recovery phases at 70%:10% PO . MICE and HIIE were isocaloric (115.9 ± 21.8 and 116.6 ± 35.0 kcal, respectively; p = 0.903), but differed in duration (39.8 ± 4.6 vs 32.2 ± 6.2 min; p < 0.001) and average respiratory exchange ratio (RER; 0.90 ± 0.08 vs 1.01 ± 0.07; p = 0.002). During MICE, a workrate of 24.6 ± 6.7% PO elicited a V̇O of 53.1 ± 6.5% V̇O (10.1 ± 2.2 ml kg  min ). During HIIE, a workrate at 70% PO elicited 88.3 ± 6.7% V̇O (16.9 ± 4.2 ml kg  min ), and 29.4 ± 7.7% of the session was spent at or above 80% V̇O . During HIIE working phase, RER declined from the first to last interval (1.08 ± 0.07 vs 0.98 ± 0.09; p < 0.001), reflecting an initially high but declining glycolytic rate. Compared with MICE, HIIE imposed a greater physiological stimulus while requiring less time to achieve a target caloric expenditure. Thus, exercise intensity might be an important consideration in the tailoring of exercise prescription to address the cardiometabolic comorbidities of SCI

Physiological responses to moderate intensity continuous and high-intensity interval exercise in persons with paraplegia

Study design: Randomized crossover. Objectives: To test differences in the duration and magnitude of physiological response to isocaloric moderate intensity continuous (MICE) and high-intensity interval exercise (HIIE) sessions in persons with spinal cord injury (SCI). Setting: Academic medical center in Miami, FL, USA. Methods: Ten adult men (mean ± s.d.; 39 ± 10 year old) with chronic (13.2 ± 8.8 year) paraplegia (T2–T10) completed a graded exercise test. Then, in a randomized order, participants completed MICE and HIIE for a cost of 120 kcal. MICE was performed at 24.6% PO peak. During HIIE, exercise was completed in 2 min work and recovery phases at 70%:10% PO peak. Results: MICE and HIIE were isocaloric (115.9 ± 21.8 and 116.6 ± 35.0 kcal, respectively; p = 0.903), but differed in duration (39.8 ± 4.6 vs 32.2 ± 6.2 min; p &lt; 0.001) and average respiratory exchange ratio (RER; 0.90 ± 0.08 vs 1.01 ± 0.07; p = 0.002). During MICE, a workrate of 24.6 ± 6.7% PO peak elicited a V̇O 2 of 53.1 ± 6.5% V̇O 2peak (10.1 ± 2.2 ml kg −1 min −1). During HIIE, a workrate at 70% PO peak elicited 88.3 ± 6.7% V̇O 2peak (16.9 ± 4.2 ml kg −1 min −1), and 29.4 ± 7.7% of the session was spent at or above 80% V̇O 2peak. During HIIE working phase, RER declined from the first to last interval (1.08 ± 0.07 vs 0.98 ± 0.09; p &lt; 0.001), reflecting an initially high but declining glycolytic rate. Conclusions: Compared with MICE, HIIE imposed a greater physiological stimulus while requiring less time to achieve a target caloric expenditure. Thus, exercise intensity might be an important consideration in the tailoring of exercise prescription to address the cardiometabolic comorbidities of SCI. </p

Where are the Hedgehogs in Nematics?

In experiments which take a liquid crystal rapidly from the isotropic to the nematic phase, a dense tangle of defects is formed. In nematics, there are in principle both line and point defects (``hedgehogs''), but no point defects are observed until the defect network has coarsened appreciably. In this letter the expected density of point defects is shown to be extremely low, approximately $10^{-8}$ per initially correlated domain, as result of the topology (specifically, the homology) of the order parameter space.Comment: 6 pages, latex, 1 figure (self-unpacking PostScript)

Effects of exercise mode on postprandial metabolism in humans with chronic paraplegia:Exercise and postprandial metabolism in SCI

PURPOSE: The purpose of this study was to assess the acute effects of exercise mode and intensity on postprandial macronutrient metabolism.METHODS: Ten healthy men age 39 ± 10 yr with chronic paraplegia (13.2 ± 8.8 yr, ASIA A-C) completed three isocaloric bouts of upper-body exercise and a resting control. After an overnight fast, participants completed circuit resistance exercise (CRE) first and the following conditions in a randomized order, separated by >48 h: i) control (CON), ~45-min seated rest; ii) moderate-intensity continuous exercise (MICE), ~40-min arm cranking at a resistance equivalent to ~30% peak power output (PPO); and iii) high-intensity interval exercise (HIIE), ~30 min arm cranking with resistance alternating every 2 min between 10% PPO and 70% PPO. After each condition, participants completed a mixed-meal tolerance test consisting of a 2510-kJ liquid meal (35% fat, 50% carbohydrate, 15% protein). Blood and expired gas samples were collected at baseline and regular intervals for 150 min after a meal.RESULTS: An interaction (P < 0.001) was observed, with rates of lipid oxidation elevated above CON in HIIE until 60 min after a meal and in CRE at all postprandial time points up to 150 min after a meal. Postprandial blood glycerol was greater in MICE (P = 0.020) and CRE (P = 0.001) compared with CON. Furthermore, nonesterified fatty acid area under the curve had a moderate-to-strong effect in CRE versus MICE and HIIE (Cohen's d = -0.76 and -0.50, respectively).CONCLUSIONS: In persons with paraplegia, high-intensity exercise increased postprandial energy expenditure independent of the energy cost of exercise. Furthermore, exercise combining resistance and endurance modes (CRE) showed the greater effect on postprandial lipid oxidation

Effects of exercise mode on postprandial metabolism in humans with chronic paraplegia:Exercise and postprandial metabolism in SCI

PURPOSE: The purpose of this study was to assess the acute effects of exercise mode and intensity on postprandial macronutrient metabolism.METHODS: Ten healthy men age 39 ± 10 yr with chronic paraplegia (13.2 ± 8.8 yr, ASIA A-C) completed three isocaloric bouts of upper-body exercise and a resting control. After an overnight fast, participants completed circuit resistance exercise (CRE) first and the following conditions in a randomized order, separated by &gt;48 h: i) control (CON), ~45-min seated rest; ii) moderate-intensity continuous exercise (MICE), ~40-min arm cranking at a resistance equivalent to ~30% peak power output (PPO); and iii) high-intensity interval exercise (HIIE), ~30 min arm cranking with resistance alternating every 2 min between 10% PPO and 70% PPO. After each condition, participants completed a mixed-meal tolerance test consisting of a 2510-kJ liquid meal (35% fat, 50% carbohydrate, 15% protein). Blood and expired gas samples were collected at baseline and regular intervals for 150 min after a meal.RESULTS: An interaction (P &lt; 0.001) was observed, with rates of lipid oxidation elevated above CON in HIIE until 60 min after a meal and in CRE at all postprandial time points up to 150 min after a meal. Postprandial blood glycerol was greater in MICE (P = 0.020) and CRE (P = 0.001) compared with CON. Furthermore, nonesterified fatty acid area under the curve had a moderate-to-strong effect in CRE versus MICE and HIIE (Cohen's d = -0.76 and -0.50, respectively).CONCLUSIONS: In persons with paraplegia, high-intensity exercise increased postprandial energy expenditure independent of the energy cost of exercise. Furthermore, exercise combining resistance and endurance modes (CRE) showed the greater effect on postprandial lipid oxidation.</p

Pan-viral serology implicates enteroviruses in acute flaccid myelitis.

Since 2012, the United States of America has experienced a biennial spike in pediatric acute flaccid myelitis (AFM)1-6. Epidemiologic evidence suggests non-polio enteroviruses (EVs) are a potential etiology, yet EV RNA is rarely detected in cerebrospinal fluid (CSF)2. CSF from children with AFM (n = 42) and other pediatric neurologic disease controls (n = 58) were investigated for intrathecal antiviral antibodies, using a phage display library expressing 481,966 overlapping peptides derived from all known vertebrate and arboviruses (VirScan). Metagenomic next-generation sequencing (mNGS) of AFM CSF RNA (n = 20 cases) was also performed, both unbiased sequencing and with targeted enrichment for EVs. Using VirScan, the viral family significantly enriched by the CSF of AFM cases relative to controls was Picornaviridae, with the most enriched Picornaviridae peptides belonging to the genus Enterovirus (n = 29/42 cases versus 4/58 controls). EV VP1 ELISA confirmed this finding (n = 22/26 cases versus 7/50 controls). mNGS did not detect additional EV RNA. Despite rare detection of EV RNA, pan-viral serology frequently identified high levels of CSF EV-specific antibodies in AFM compared with controls, providing further evidence for a causal role of non-polio EVs in AFM

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