Low-profile and wearable energy harvester based on plucked piezoelectric cantilevers

The Pizzicato Energy Harvester (EH) introduced the technique of frequency up-conversion to piezoelectric EHs wearable on the lateral side of the knee-joint. The operation principle is to pluck the piezoelectric bimorphs with plectra so that they produce electrical energy during the ensuing mechanical vibrations. The device presented in this work is, in some ways, an evolution of the earlier Pizzicato: it is a significantly more compact and lighter device; the central hub holds 16 piezoelectric bimorphs shaped as trapezoids, which permits a sleek design and potentially increased energy output for the same bimorph area. Plectra were formed by Photochemical Machining of a 100-μm-thick steel sheet. To avoid the risk of short-circuiting, the plectra were electrically passivated by sputtering a 100 nm layer of ZrO2. Bench tests with the steel plectra showed a very large energy generation. Polyimide plectra were also manufactured with a cutting plotter from a 125μm-thick film. Besides bench tests, a volunteer wore the device while walking on flat ground or climbing stairs, with a measured energy output of approximately 0.8 mJ per step. Whereas most of the tests were performed by the traditional method of discharging the rectified output from the EH onto a resistive load, tests were performed also with a circuit offering a stabilised 3.3 V supply. The circuit produced a stable 0.1 mA supply during running gait with kapton plectra

Understanding Orthostatic Intolerance and Exercise Programming for the Health and Fitness Practitioner

The purpose of this manuscript is to briefly review Orthostatic Intolerance (OI) and discuss proper exercise programming and progression guidelines for working with those affected by OI; a disorder associated with autonomic nervous system dysfunction, characterized by a difficulty standing upright. In order to do this, we performed a review of the published literature using google scholar and PubMed search engines. Evidence indicated that a light to moderate intensity aerobic exercise program would aid in improving orthostatic tolerance. Previous studies have indicated that progressive resistance training aids in mechanisms that are dysfunctional in OI such as blood volume increases and a decrease in baroreceptor responses. Preparticipation physical exams and initial value assessments are an integral part of the OI exercise prescription as many individuals will have unhealthy vital capacities due to OI symptomology and accompanying deconditioning. Many Individuals with OI have responded positively to aerobic and resistance training. Using informed judgment when prescribing exercise and careful progression of frequency, intensity, and duration should be considered

Direct measurement of the charge distribution along a biased carbon nanotube bundle using electron holography

Nanowires and nanotubes can be examined in the transmission electron microscope under an applied bias. Here we introduce a model-independent method, which allows the charge distribution along a nanowire or nanotube to be measured directly from the Laplacian of an electron holographic phase image. We present results from a biased bundle of carbon nanotubes, in which we show that the charge density increases linearly with distance from its base, reaching a value of similar to 0.8 electrons/nm near its tip. (C) 2011 American Institute of Physics. [doi:10.1063/1.3598468

The Influence of a Total Body Resistance Training Program on Autonomic Modulation and Strength Variables in Young Adults

International Journal of Exercise Science 14(2): 802-814, 2021. The purpose of this study was to examine autonomic modulation using multiple quantitative measures before and after a resistance training (RT) intervention. Seventeen young adults (age 18-35 years) were tested for body composition, muscular strength, and autonomic activity. The RT protocol targeted total-body large muscle groups, which were performed three days a week for eight-weeks. Autonomic assessments included respiratory sinus arrhythmia (RSA), static handgrip exercise, Valsalva maneuver, heart rate variability (HRV), and tilt-table testing. The main finding was that tilt-table duration increased by 68 seconds (p = 0.05) after RT. Upper body strength increased by 11.2 kg (p = 0.001) and lower body strength increased by 68.3 kg (p \u3c 0.001) following completion of the RT intervention. The average total lean mass increased by 1.5 kg (p \u3c 0.01), while total fat mass was unchanged (∆ = 0.5 kg, p = 0.23). RSA (∆ = 0.4, p = 0.89), Valsalva ratio (∆= -0.09, p = 0.48), static handgrip (∆ = 8 mm Hg, p = 0.07), and HRV (∆ = -0.4, p = 0.53) were not affected by RT. The results from this study suggest that RT improves tilt-table tolerance in a young healthy population as evidence by improved tilt-table duration. However, RT seemed to have no effect on cardio-vagal or adrenergic function

ISO observations of a sample of Compact Steep Spectrum and GHz Peaked Spectrum Radio Galaxies

We present results from observations obtained with ISOPHOT, on board the ISO satellite, of a representative sample of seventeen CSS/GPS radio galaxies and of a control sample of sixteen extended radio galaxies spanning similar ranges in redshift (0.2 = 10^26 W/Hz). The observations have been performed at lambda = 60, 90, 174 and 200 microns. Seven of the CSS/GPS sources have detections >= 3 sigma at one or more wavelengths, one of which is detected at >= 5 sigma. By co-adding the data we have obtained average flux densities at the four wavelengths. We found no evidence that the FIR luminosities of the CSS/GPS sources are significantly different from those of the extended objects and therefore there is not any support for CSS/GPS sources being objects "frustrated" by an abnormally dense ambient medium. The two samples were then combined, providing FIR information on a new sample of radio galaxies at intermediate redshifts. We compare this information with what previously known from IRAS and discuss the average properties of radio galaxies in the redshift range 0.2 - 0.8. The FIR emission cannot be accounted for by extrapolation of the synchrotron radio spectrum and we attribute it to thermal dust emission. The average FIR luminosity is >= 6*10^11 L_sun. Over the observed frequency range the infrared spectrum can be described by a power law with spectral index alpha >~1.0 +/- 0.2. Assuming the emission to be due to dust, a range of temperatures is required, from >=80 K to \~25 K. The dust masses required to explain the FIR emission range from 5*10^5 M_sun for the hotter component up to 2*10^8 M_sun for the colder one. (abridged)Comment: Astronomy & Astrophysics, in press, 16 pages, 2 Figure

Effect of Sex and Menstrual Cycle on Skin Sensory Nerve Contribution to Local Heating

International Journal of Exercise Science 12(2): 1265-1279, 2019. The purpose of this study was to determine sex differences in the contribution of sensory nerves to rapid cutaneous thermal hyperemia. Healthy young females (n = 15, tested during both the early follicular (EF) and the mid-luteal (ML) phase of the menstrual cycle) and males (n = 15) had a 4 cm2 area of skin on one forearm and one leg treated with a eutectic mixture of local anesthetic (EMLA). EMLA sites, along with corresponding control sites, were instrumented with laser Doppler flowmetry probes and local skin heaters. Baseline (33 °C), rapid and sustained vasodilation (42 °C), and maximal vasodilation (44 °C) skin blood flow data were obtained and expressed as a percentage of maximal cutaneous vascular conductance (%CVCmax). Contribution of sensory nerve involvement was determined by comparing the EMLA site to its matched control site utilizing the formula [(% CVCmax control - % CVCmax treatment) / % CVCmax control] × 100. The contribution of sensory nerves to rapid cutaneous thermal hyperemia in the forearm was 24 ± 18 %CVCmax in males, 41 ± 17 %CVCmax in ML females (p = 0.02 vs. males), and 35 ± 17 %CVCmax in EF females (p \u3e 0.05 vs. males). In the leg, the contribution of sensory nerves was 16 ± 15 %CVCmax in males, 34 ± 17 %CVCmax for ML females (p = 0.02 vs. males), and 28 ± 21 %CVCmax in EF females (p \u3e 0.05 vs. males). ML females exhibited a greater contribution of sensory nerves to rapid cutaneous thermal hyperemia in the forearm and leg, possibly attributed to elevated reproductive hormones during the ML phase

Correlated Prompt Fission Data in Transport Simulations

Detailed information on the fission process can be inferred from the observation, modeling and theoretical understanding of prompt fission neutron and $\gamma$-ray~observables. Beyond simple average quantities, the study of distributions and correlations in prompt data, e.g., multiplicity-dependent neutron and \gray~spectra, angular distributions of the emitted particles, $n$-$n$, $n$-$\gamma$, and $\gamma$-$\gamma$~correlations, can place stringent constraints on fission models and parameters that would otherwise be free to be tuned separately to represent individual fission observables. The FREYA~and CGMF~codes have been developed to follow the sequential emissions of prompt neutrons and $\gamma$-rays~from the initial excited fission fragments produced right after scission. Both codes implement Monte Carlo techniques to sample initial fission fragment configurations in mass, charge and kinetic energy and sample probabilities of neutron and $\gamma$~emission at each stage of the decay. This approach naturally leads to using simple but powerful statistical techniques to infer distributions and correlations among many observables and model parameters. The comparison of model calculations with experimental data provides a rich arena for testing various nuclear physics models such as those related to the nuclear structure and level densities of neutron-rich nuclei, the $\gamma$-ray~strength functions of dipole and quadrupole transitions, the mechanism for dividing the excitation energy between the two nascent fragments near scission, and the mechanisms behind the production of angular momentum in the fragments, etc. Beyond the obvious interest from a fundamental physics point of view, such studies are also important for addressing data needs in various nuclear applications. (See text for full abstract.)Comment: 39 pages, 57 figure files, published in Eur. Phys. J. A, reference added this versio

Anchoring of proteins to lactic acid bacteria

The anchoring of proteins to the cell surface of lactic acid bacteria (LAB) using genetic techniques is an exciting and emerging research area that holds great promise for a wide variety of biotechnological applications. This paper reviews five different types of anchoring domains that have been explored for their efficiency in attaching hybrid proteins to the cell membrane or cell wall of LAB. The most exploited anchoring regions are those with the LPXTG box that bind the proteins in a covalent way to the cell wall. In recent years, two new modes of cell wall protein anchoring have been studied and these may provide new approaches in surface display. The important progress that is being made with cell surface display of chimaeric proteins in the areas of vaccine development and enzyme- or whole-cell immobilisation is highlighted.

Machine learning predicts lung recruitment in acute respiratory distress syndrome using single lung CT scan

Background: To develop and validate classifier models that could be used to identify patients with a high percentage of potentially recruitable lung from readily available clinical data and from single CT scan quantitative analysis at intensive care unit admission. 221 retrospectively enrolled mechanically ventilated, sedated and paralyzed patients with acute respiratory distress syndrome (ARDS) underwent a PEEP trial at 5 and 15 cmH2O of PEEP and two lung CT scans performed at 5 and 45 cmH2O of airway pressure. Lung recruitability was defined at first as percent change in not aerated tissue between 5 and 45 cmH2O (radiologically defined; recruiters: Δ45-5non-aerated tissue > 15%) and secondly as change in PaO2 between 5 and 15 cmH2O (gas exchange-defined; recruiters: Δ15-5PaO2 > 24 mmHg). Four machine learning (ML) algorithms were evaluated as classifiers of radiologically defined and gas exchange-defined lung recruiters using different models including different variables, separately or combined, of lung mechanics, gas exchange and CT data. Results: ML algorithms based on CT scan data at 5 cmH2O classified radiologically defined lung recruiters with similar AUC as ML based on the combination of lung mechanics, gas exchange and CT data. ML algorithm based on CT scan data classified gas exchange-defined lung recruiters with the highest AUC. Conclusions: ML based on a single CT data at 5 cmH2O represented an easy-to-apply tool to classify ARDS patients in recruiters and non-recruiters according to both radiologically defined and gas exchange-defined lung recruitment within the first 48 h from the start of mechanical ventilation