1,619 research outputs found
A municipality-level analysis of excess mortality in Italy in the period January-April 2020
BACKGROUND: the first confirmed cases of COVID-19 in WHO European Region was reported at the end of January 2020 and, from that moment, the epidemic has been speeding up and rapidly spreading across Europe. The health, social, and economic consequences of the pandemic are difficult to evaluate, since there are many scientific uncertainties and unknowns. OBJECTIVES: the main focus of this paper is on statistical methods for profiling municipalities by excess mortality, directly or indirectly caused by COVID-19. METHODS: the use of excess mortality for all causes has been advocated as a measure of impact less vulnerable to biases. In this paper, observed mortality for all causes at municipality level in Italy in the period January-April 2020 was compared to the mortality observed in the corresponding period in the previous 5 years (2015-2019). Mortality data were made available by the Ministry of Internal Affairs Italian National Resident Population Demographic Archive and the Italian National Institute of Statistics (Istat). For each municipality, the posterior predictive distribution under a hierarchical null model was obtained. From the posterior predictive distribution, we obtained excess death counts, attributable community rates and q-values. Full Bayesian models implemented via MCMC simulations were used. RESULTS: absolute number of excess deaths highlights the burden paid by major cities to the pandemic. The Attributable Community Rate provides a detailed picture of the spread of the pandemic among the municipalities of Lombardy, Piedmont, and Emilia-Romagna Regions. Using Q-values, it is clearly recognizable evidence of an excess of mortality from late February to April 2020 in a very geographically scattered number of municipalities. A trade-off between false discoveries and false non-discoveries shows the different values of public health actions. CONCLUSIONS: despite the variety of approaches to calculate excess mortality, this study provides an original methodological approach to profile municipalities with excess deaths accounting for spatial and temporal uncertainty
Demonstration of FPGA acceleration of Monte Carlo simulation
We present results from a stand-alone simulation of electron single Coulomb scattering as implemented completely on an Field Programmable Gate Array (FPGA) architecture and compared with an identical simulation on a standard CPU. FPGA architectures offer unprecedented speed-up capability for Monte Carlo simulations, however with the caveats of lengthy development cycles and resource limitation, particularly in terms of on-chip memory and DSP blocks. As a proof of principle of acceleration on an FPGA, we chose a single scattering process of electrons in water at an energy of 6 MeV. The initial code-base was implemented in C++ and optimised for CPU processing. To measure the potential performance gains of FPGAs compared to modern multi-core CPUs we computed 100M histories of a 6 MeV electron interacting in water. Without performing any hardware-specific optimisation, the results show that the FPGA implementation is over 110 times faster than an optimised parallel implementation running on 12 CPU-cores, and over 270 times faster than a sequential single-core CPU implementation. The results on both architectures were statistically equivalent. The successful implementation and acceleration results are very encouraging for the future exploitation of more sophisticated Monte Carlo simulation on FPGAs for High Energy Physics applications
Realisation of an optical pressure standard by a multi-reflection interferometric technique
A novel realization of an optical pressure standard, alternative to Fabry-Perot cavity-based techniques, is presented. It is based on the measurement of the refractive index of a gas through an unbalanced homodyne interferometer, designed to have one of its two arms formed by a multi reflection double mirror assembly to establish an unbalance length larger than 6 m in a compact setup.
The paper illustrates the most important steps concerning its realization: the estimate of the pressure-induced deformation of the interferometer, the temperature control at millikelvin level and the measurement in vacuum of the unbalance of the interferometer.
The evaluation of the uncertainty of the realized optical pressure standard currently demonstrated to fulfill the main goal of having the ability to measure pressure with a relative uncertainty of 10 ppm at 100 kPa
Misura di un artefatto dodecaedrico tramite CMM
Nel presente RT si descrive l’attività svolta presso il lab. CMM dell’INRiM al fine di ottenere la misura di alcune caratteristiche geometriche di un artefatto, realizzato con tecniche di additive manufacturing. La destinazione operativa dell’oggetto è quella di fungere da campione per rilievi di fotogrammetria.This RT describes the activity carried out at the lab. CMM of INRiM in order to obtain the measurement of some geometric characteristics of an artefact, realized by means of additive manufacturing method. The purpose of the object is to serve as a sample for photogrammetric surveys
Charge-carrier complexes in monolayer semiconductors
The photoluminescence (PL) spectra of monolayer (1L) semiconductors feature
peaks ascribed to different charge-carrier complexes. We perform diffusion
quantum Monte Carlo simulations of the binding energies of these complexes and
examine their response to electric and magnetic fields. We focus on quintons
(charged biexcitons), since they are the largest free charge-carrier complexes
in transition-metal dichalcogenides (TMDs). We examine the accuracy of the
Rytova-Keldysh interaction potential between charges by comparing the binding
energies of charge-carrier complexes in 1L-TMDs with results obtained using
interaction potentials. Magnetic fieldsT change the
binding energies (BEs) by meV,T, in agreement with experiments,
with the BE variations of different complexes being very similar. Our results
will help identify charge complexes in the PL spectra of 1L-semiconductor
The role of mercury, selenium and the Se-Hg antagonism on cognitive neurodevelopment: A 40-month follow-up of the Italian mother-child PHIME cohort
Despite a 15-year long effort to define the \u201csafety\u201d of fish intake during pregnancy, there remains still uncertainty on this important public health issue. The evaluation of the toxic effects of contaminants, particularly mercury (Hg) in fish-eating populations is complicated by the fact that sea-food is also rich in beneficial nutrients, such as selenium (Se). There is toxicological plausibility of an antagonistic effects between Se and Hg, and some theoretical support for the inclusion of the Se\u2013Hg interaction to better assess the risk linked with fish intake. To assess the effects of exposure to low-level Hg through fish consumption on the developing brain and the interaction between Hg and Se, we conducted an analysis at age 40 months in Italian children, enrolled in a prospective mother-child cohort, comparing additive and multiplicative models. Participant subjects were the 470 children born within the Northern Adriatic Cohort II (NAC-II) cohort who were tested by using the Bayley Scales of Infant and Toddler Development third edition (Bayley-III) (BSID-III) at age 40. Family demographic and socioeconomic information, pregnancy and delivery history, parental and child medical history and food consumption were assessed through questionnaires. Maternal blood samples were collected during pregnancy, cord blood at birth and maternal milk 1 month after delivery. As other exposures of interest, we considered the level of Se in maternal and cord blood and in breast milk and the potential Se\u2013Hg antagonism. Se and inverse of THg (1:THg) concentrations were categorized according to the tertiles of their distributions, in low, medium and high levels of exposure. The lower end of the composite cognitive score distribution closest to 20% was defined as suboptimal development. Multiple logistic regression were applied to assess the association between the dichotomized composite cognitive score and the categorized exposure to Se and 1:THg, and the antagonism between Se and 1:THg. In the recruiting period, 900 pregnant women were enrolled in the cohort; 767 of these remained in the study at delivery and 470 children at 40 months. After excluding preterm births, 456 children were used in the final analyses. The larger difference in risk for suboptimal neurodevelopment was observed for the category with High THg and Low Se with OR = 2.55 (90% CI 1.02; 6.41) under the multiplicative and OR = 1.33 (90% CI 0.80; 1.87) under the additive model. The category High THg and High Se showed a very slightly better fit of the additive model (OR = 1.07, 90% CI 0.65; 1.50) versus the multiplicative (OR = 1.66, 90% CI 0.73; 1.77). A negative \u2013 antagonistic \u2013 interaction term for this category was estimated under the multiplicative model giving an OR = 1.17 (90% CI 0.42; 3.28). Although this evidence of the effects of the Se\u2013Hg antagonism on the children neuro-development needs to be confirmed, if Se can counterbalance Hg toxicity, the evaluation of the effect on human health of fish consumption, should also consider the diverse ratios between Se and Hg concentration in different fish species
Resistance and resilience of ecosystem descriptors and properties to dystrophic events: a study case in a Mediterranean lagoon
Mediterranean lagoons are naturally exposed, during the dry season, to dystrophic and hypoxic events determining dis-equilibrium conditions along temporal and spatial scales, which are linked to metabolism and life cycle of the biotic components. In summer 2008, Lesina lagoon (SE Italian coastline) was interested by a geographically localized dystrophic crisis which affected up to 8% of the total lagoon surface. Temporal dynamics of principal descriptors of abiotic (water, sediment) and biotic (phytoplankton, benthic macroinvertebrate) compartments have been followed during the 2008 by collecting data inside stressed and control lagoon areas before a dystrophic event and in the six months after the dystrophic event. The aim of the study was to analyse the pathways of ecosystem responses to dystrophic stress, searching for the characteristic scales of ecosystem compartment resistance and resilience. The characteristic time-scale of abiotic and biotic component time responses varied from days, for the selected markers of the water column, to year, for the benthic ones. Short-term biotic and abiotic responses in the water column were strongly coupled while biotic and abiotic responses at the sediment level were remarkably un-coupled. Dynamics and recovery time of water column and benthic components do not match in Lesina following the dystrophic crisis, highlighting an intrinsic individualistic behavior within the lagoon community driving ecosystem processes and ecosystem level responses. Taxonomic and non-taxonomic descriptors of both phytoplankton and benthic macroinvertebrates showed different response patterns as early warning signals and overall resilience. The emphasized differences in the stability components, i.e., resistance and resilience, of water column and sediment abiotic and biotic characteristics as well as of taxonomic and non-taxonomic descriptors has key implication in planning monitoring strategies and programs for transitional waters in the Mediterranean and Black Sea EcoRegions
p-wave triggered superconductivity in single-layer graphene on an electron-doped oxide superconductor
Electron pairing in the vast majority of superconductors follows the Bardeen-Cooper-Schrieffer theory of superconductivity, which describes the condensation of electrons into pairs with antiparallel spins in a singlet state with an s-wave symmetry. Unconventional superconductivity was predicted in single-layer graphene (SLG), with the electrons pairing with a -wave or chiral d-wave symmetry, depending on the position of the Fermi energy with respect to the Dirac point. By placing SLG on an electron-doped (non-chiral) d-wave superconductor and performing local scanning tunnelling microscopy and spectroscopy, here we show evidence for a -wave triggered superconducting density of states in SLG. The realization of unconventional superconductivity in SLG offers an exciting new route for the development of p-wave superconductivity using two-dimensional materials with transition temperatures above 4.2 K.The work was funded by the following agencies: Royal Society (‘Superconducting Spintronics’), Leverhulme Trust (IN-2013-033), Schiff Foundation, the EPSRC (EP/N017242/1, EP/G037221/1, EP/K01711X/1, EP/K017144/1, EP/N010345/1, EP/M507799/1, EP/L016087/1), ERC Grant Hetero2D, EU Graphene Flagship, COST Action MP-1201, MSCA-IFEF-ST No. 656485-Spin3, Outstanding Academic Fellows programme at NTNU, Research Council of Norway (205591, 216700 and 24080)
Large-scale quantum-emitter arrays in atomically thin semiconductors
This is the final version. Available on open access from Nature Research via the DOI in this recordData availability:
The data that supports the findings of this study are available from the corresponding author upon request.Quantum light emitters have been observed in atomically thin layers of transition metal dichalcogenides. However, they are found at random locations within the host material and usually in low densities, hindering experiments aiming to investigate this new class of emitters. Here, we create deterministic arrays of hundreds of quantum emitters in tungsten diselenide and tungsten disulphide monolayers, emitting across a range of wavelengths in the visible spectrum (610–680 nm and 740–820 nm), with a greater spectral stability than their randomly occurring counterparts. This is achieved by depositing monolayers onto silica substrates nanopatterned with arrays of 150-nm-diameter pillars ranging from 60 to 190 nm in height. The nanopillars create localized deformations in the material resulting in the quantum confinement of excitons. Our method may enable the placement of emitters in photonic structures such as optical waveguides in a scalable way, where precise and accurate positioning is paramount.European CommissionEuropean Research Council (ERC)Engineering and Physical Sciences Research Council (EPSRC)National Science Foundation (NSF
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