Modelling stunting in LiST: the effect of applying smoothing to linear growth data.

BACKGROUND: The Lives Saved Tool (LiST) is a widely used resource for evidence-based decision-making regarding health program scale-up in low- and middle-income countries. LiST estimates the impact of specified changes in intervention coverage on mortality and stunting among children under 5 years of age. We aimed to improve the estimates of the parameters in LiST that determine the rate at which the effects of interventions to prevent stunting attenuate as children get older. METHODS: We identified datasets with serial measurements of children's lengths or heights and used random effects models and restricted cubic splines to model the growth trajectories of children with at least six serial length/height measurements. We applied WHO growth standards to both measured and modelled (smoothed) lengths/heights to determine children's stunting status at multiple ages (1, 6, 12, 24 months). We then calculated the odds ratios for the association of stunting at one age point with stunting at the next ("stunting-to-stunting ORs") using both measured and smoothed data points. We ran analyses in LiST to compare the impact on intervention effect attenuation of using smoothed rather than measured stunting-to-stunting ORs. RESULTS: A total of 21,786 children with 178,786 length/height measurements between them contributed to our analysis. The odds of stunting at a given age were strongly related to whether a child is stunted at an earlier age, using both measured and smoothed lengths/heights, although the relationship was stronger for smoothed than measured lengths/heights. Using smoothed lengths/heights, we estimated that children stunted at 1 month have 45 times the odds of being stunted at 6 months, with corresponding odds ratios of 362 for the period 6 to 12 months and 175 for the period 12 to 24 months. Using the odds ratios derived from the smoothed data in LiST resulted in a somewhat slower attenuation of intervention effects over time, but substantial attenuation was still observed in the LiST outputs. For example, in Mali the effect of effectively eliminating SGA births reduced prevalence of stunting at age 59 months from 44.4% to 43.7% when using odds ratios derived from measured lengths/heights and from 44.4% to 41.9% when using odds ratios derived from smoothed lengths/heights. CONCLUSIONS: Smoothing of children's measured lengths/heights increased the strength of the association between stunting at a given age and stunting at an earlier age. Using odds ratios based on smoothed lengths/heights in LiST resulted in a small reduction in the attenuation of intervention effects with age and thus some increase in the estimated benefits, and may better reflect the true benefits of early nutritional interventions

Experimental study of a flag-flutter energy harvester

In the present era, the possibility to generate electrical energy from an operational environment is a critical factor for an aerospace industry, particularly to drive microelectronic components. In this research, a solution for energy harvesting mechanism based on fluid-structure interaction (FSI) is investigated via experimental campaign. The possibility to harvest energy from Limit Cycle Oscillations (LCOs) by means of piezoelectric transduction is investigated experimentally. A typical condition for energy harvesting, which requires a strong interaction between the external energy and the components where the harvester is embedded. Moreover, the flutter instability of a cantilevered flag with piezoelectric and aluminium patches, subjected to an axial flow has been experimentally studied. The practical interest of this instability mechanism, which can lead to self-sustained oscillations, is the possible application inflow energy harvesting. The presented model is suitable to harvest energy and to drive wireless sensors. The maximum power output obtained by the designed piezoelectric aeroelastic energy harvester (PAEH) is found to be 1.12 mW for 66.6KΩ of resistance

Flutter investigation for piezoelectric aeroelastic energy harvester

In the present era, the possibility to generate electrical energy from an operational environment is a critical factor for an aerospace industry, particularly to drive microelectronic components. In this research, a solution for energy harvesting mechanism based on fluid-structure interaction (FSI) is investigated via experimental campaign. The possibility to harvest energy from Limit Cycle Oscillations (LCOs) by means of piezoelectric transduction is investigated experimentally. A typical condition for energy harvesting, which requires a strong interaction between the external energy and the components where the harvester is embedded. Moreover, the flutter instability of a cantilevered flag with and without piezoelectric patches, subjected to an axial flow has been experimentally studied. The practical interest of this instability mechanism, which can lead to self-sustained oscillations, is the possible application in ow energy harvesting. The presented model is suitable to harvest energy and to drive wireless sensors. The maximum power output obtained by the designed piezoelectric aeroelastic energy harvester (PAEH) is found to be 1.12mW for 66.6K-Ohm of resistance

Experimental evaluation of piezoelectric energy harvester based on flag-flutter

In the present era, the possibility to generate electrical energy from an operational environment is a critical factor for the aerospace industry, particularly to drive microelectronic components. In this research, a solution for energy harvesting mechanism based on fluid-structure interaction (FSI) is investigated via the experimental campaign. The possibility to harvest energy from Limit Cycle Oscillations (LCOs) by means of piezoelectric transduction is investigated experimentally. Moreover, the flutter instability of a cantilevered flag with piezoelectric patches, subjected to an axial flow has been experimentally studied. The practical interest of this instability mechanism, which can lead to self-sustained oscillations, is the possible application in flow energy harvesting. The presented model is suitable to harvest energy and to drive wireless sensors. The maximum power output obtained by the designed piezoelectric aeroelastic energy harvester (PAEH) is found to be 1.12 mW for 66.6k-Ohm of resistance

LPNHE scientific perspectives for the European Strategy for Particle Physics

This note summarizes the activities and the scientific and technical perspectives of the Laboratoire de Physique Nucleaire et de Hautes Energies (LPNHE) at Sorbonne University, Paris. Although the ESPP is specifically aimed at particle physics, we discuss in this note in parallel the three scientific lines developed at LPNHE (Particle Physics, Astroparticles, Cosmology), first with the current scientific activities, then for the future activities. However, our conclusions and recommendations are focused on the particle physics strategy

Energy resolution and linearity of XENON1T in the MeV energy range

Xenon dual-phase time projection chambers designed to search for weakly interacting massive particles have so far shown a relative energy resolution which degrades with energy above ∼ 200 keV due to the saturation effects. This has limited their sensitivity in the search for rare events like the neutrinoless double-beta decay of 136Xe at its Q value, Qββ≃2.46MeV. For the XENON1T dual-phase time projection chamber, we demonstrate that the relative energy resolution at 1σ/μ is as low as (0.80 ± 0.02) % in its one-ton fiducial mass, and for single-site interactions at Qββ. We also present a new signal correction method to rectify the saturation effects of the signal readout system, resulting in more accurate position reconstruction and indirectly improving the energy resolution. The very good result achieved in XENON1T opens up new windows for the xenon dual-phase dark matter detectors to simultaneously search for other rare events

Projected WIMP sensitivity of the XENONnT dark matter experiment

XENONnT is a dark matter direct detection experiment, utilizing 5.9 t of instrumented liquid xenon, located at the INFN Laboratori Nazionali del Gran Sasso. In this work, we predict the experimental background and project the sensitivity of XENONnT to the detection of weakly interacting massive particles (WIMPs). The expected average differential background rate in the energy region of interest, corresponding to (1, 13) keV and (4, 50) keV for electronic and nuclear recoils, amounts to 12.3 ± 0.6 (keV t y)-1 and (2.2± 0.5)× 10-3 (keV t y)-1, respectively, in a 4 t fiducial mass. We compute unified confidence intervals using the profile construction method, in order to ensure proper coverage. With the exposure goal of 20 t y, the expected sensitivity to spin-independent WIMP-nucleon interactions reaches a cross-section of 1.4×10-48 cm2 for a 50 GeV/c2 mass WIMP at 90% confidence level, more than one order of magnitude beyond the current best limit, set by XENON1T . In addition, we show that for a 50 GeV/c2 WIMP with cross-sections above 2.6×10-48 cm2 (5.0×10-48 cm2) the median XENONnT discovery significance exceeds 3σ (5σ). The expected sensitivity to the spin-dependent WIMP coupling to neutrons (protons) reaches 2.2×10-43 cm2 (6.0×10-42 cm2)