1,666 research outputs found
Influence of Changes in Political Barriers and of Geographic Distance on Kinship Inferred from Surnames and Migration Data in Olivenza (Spain) and Surrounding Portuguese Areas
The existing relationship between human populations is a function of their migratory and genetic exchange which will be inversely proportional to the distance separating them. The effect of geographic distance on population structure may be estimated by means of isonymic methods which use information on the surnames present in a territory as an approximation to the distribution of allele frequencies. The objective of this study is to analyse whether the modification in 1801 of the political border in an area surrounding the town of Olivenza, which experienced a change of sovereignty from Portugal to Spain, has had noticeable influence on the migration pattern and isolation by distance in that region. For this purpose data from marriage records of Olivenza and the neighbouring Portuguese municipalities of Alandroal, Juromenha, Elvas, Vila Boim (and Terrugem), Terena, Monsaraz, and Vila Viçosa were analysed. Two periods were considered in order to analyse the population structure: one prior to the change of domain (1775â1801), another after it (1802â1825), for which rates of diversity and inbreeding coefficients were determined. The results obtained show that following the border modification, the migration matrices changed differently according to sex, therefore altering the relationship between the various localities of the territory. In Olivenza inbreeding declined slightly and surnames became more heterogeneous. Moreover, following the change of domain the isolation by distance models illustrate a temporal reduction in the relative weight of geographical distance on inter-population kinship. The political border acted as a factor in population differentiation in the Iberian Peninsula (Spain and Portugal)
Measurements and understanding of radon adsorption in nanoporous materials
International audienceFor many experiments working at low energy and very low counting rate in particle and astroparticle physics, the background from the Radon decay chain is one of the strongest constraints. Most of the time, activated charcoal filters are used to dynamically capture the radon from the air or from the gas of the detectors. In general case activated charcoal is a good adsorptive material. It has large effective surface and broad porosity, going from macro to nanopores. However, the big constraints from futures experiments need ad hoc radon capture filters. The optimal adsorption depends on various parameters such as the correct pore size and shape, the temperature, the microscopic structure of the adsorbent or the competition between radon and carrier gas. In this context, we have developed at Centre de Physique des Particules de Marseille (CPPM), a test bench to study the radon capture in various porous materials1. Several very interesting results have been already obtained with non-standard, commercially and research adsorbents like some Carbon Molecular Sieves (CMS), organic molecular cage (CC3)2, or carbon aerogels.In this talk we present a global quantitative and qualitative study of radon adsorption in porous materials. This work is the results of the analysis of more than 30 porous materials in the framework of the collaboration between particle physicist and chemist from several universities
Search for neutrinos from transient sources with the ANTARES telescope and optical follow-up observations
The ANTARES telescope has the opportunity to detect transient neutrino
sources, such as gamma-ray bursts, core-collapse supernovae, flares of active
nuclei... To enhance the sensitivity to these sources, we have developed a new
detection method based on the optical follow-up of "golden" neutrino events
such as neutrino doublets coincident in time and space or single neutrinos of
very high energy. The ANTARES Collaboration has therefore implemented a very
fast on-line reconstruction with a good angular resolution. These
characteristics allow to trigger an optical telescope network; since February
2009. ANTARES is sending alert trigger one or two times per month to the two 25
cm robotic telescope of TAROT. This follow-up of such special events would not
only give access to the nature of the sources but also improves the sensitivity
for transient neutrino sources.Comment: 3 pages, 3 figures, Proceedings of the 31st ICRC, Lodz, Polan, July
200
MEMPHYS:A large scale water Cerenkov detector at Fr\'ejus
A water \v{C}erenkov detector project, of megaton scale, to be installed in
the Fr\'ejus underground site and dedicated to nucleon decay, neutrinos from
supernovae, solar and atmospheric neutrinos, as well as neutrinos from a
super-beam and/or a beta-beam coming from CERN, is presented and compared with
competitor projects in Japan and in the USA. The performances of the European
project are discussed, including the possibility to measure the mixing angle
and the CP-violating phase .Comment: 1+33 pages, 14 figures, Expression of Interest of MEMPHYS projec
MIMAC: MIcro-tpc MAtrix of Chambers for dark matter directional detection
Directional detection of non-baryonic Dark Matter is a promising search
strategy for discriminating WIMP events from neutrons, the ultimate background
for dark matter direct detection. This strategy requires both a precise
measurement of the energy down to a few keV and 3D reconstruction of tracks
down to a few mm. The MIMAC (MIcro-tpc MAtrix of Chambers) collaboration has
developed in the last years an original prototype detector based on the direct
coupling of large pixelized micromegas with a special developed fast
self-triggered electronics showing the feasibility of a new generation of
directional detectors. The first bi-chamber prototype has been installed at
Modane, underground laboratory in June 2012. The first undergournd background
events, the gain stability and calibration are shown. The first spectrum of
nuclear recoils showing 3D tracks coming from the radon progeny is presented.Comment: Proceedings of the 4th International Conference on Directional Dark
Matter Detection CYGNUS2013, held in Toyoma (Japan), June 201
Measurement errors and implications for preprocessing in miniaturised near-infrared spectrometers: Classification of sweet and bitter almonds as a case of study
Near-infrared (NIR) spectroscopy is a well-established analytical technique that has been used in many applications over the years. Due to the advancements in the semiconductor industry, NIR instruments have evolved from benchtop instruments to miniaturised portable devices. The miniaturised NIR instruments have gained more interest in recent years because of the fast and robust measurements they provide with almost no sample pretreatments. However, due to the very different configurations and characteristics of these instruments, they need a dedicated optimization of the measurement conditions, which is crucial for obtaining reliable results. To comprehensively grasp the capabilities and potentials offered by these sensors, it is imperative to examine errors that can affect the raw data, which is a facet frequently overlooked. In this study, measurement error covariance and correlation matrices were calculated and then visually inspected to gain insight into the error structures associated with the devices, and to find the optimal preprocessing technique that may result in the improvement of the models built. This strategy was applied to the classification of sweet and bitter almonds, which were measured with the three portable low-cost NIR devices (SCiO, FlameNIR+ and NeoSpectra Micro Development Kit) after removing the shelled, since their classification is of utmost importance for the almond industry. The results showed that bitter almonds can be classified from sweet almonds using any of the instruments after selecting the optimal preprocessing, obtained through inspection of covariance and correlation matrices. Measurements obtained with FlameNIR + device provided the best classification models with an accuracy of 98 %. The chosen strategy provides new insight into the performance characterization of the fast-growing miniaturised NIR instruments
Social impact analysis of products under a holistic approach: A case study in the meat product supply chain
Social impact assessment of products can be approached through different methodologies that need to be adapted to the particularities and features of the studied subject. Thus, the Social Life Cycle Assessment methodology can be used to assess different innovative practices of product manufacturing, under a circular economy approach, by identifying potential positive as well as negative impacts along productsâ life cycle. This paper presents the results of the Social Life Cycle Impact Assessment of a reference product from the Spanish meat industry using existing and new innovative methods of social impact analysis. Worker discrimination, health and safety for workers, consumers and local community were identified as the social aspects with relevant significance into the business or for the influence on customerâs perception of the products studied. Therefore, results can represent a reference scenario for the future assessment of innovative solutions in the Spanish meet sector. Despite the scarce use of Social Life Cycle Impact Assessment, this case study is a good example of how this innovative kind of assessment can be helpful for companies to identify their weak and strong social performance areas and design strategies to improve in Social Responsibility Management. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
Photoionization in the time and frequency domain
Ultrafast processes in matter, such as the electron emission following light
absorption, can now be studied using ultrashort light pulses of attosecond
duration (s) in the extreme ultraviolet spectral range. The lack of
spectral resolution due to the use of short light pulses may raise serious
issues in the interpretation of the experimental results and the comparison
with detailed theoretical calculations. Here, we determine photoionization time
delays in neon atoms over a 40 eV energy range with an interferometric
technique combining high temporal and spectral resolution. We spectrally
disentangle direct ionization from ionization with shake up, where a second
electron is left in an excited state, thus obtaining excellent agreement with
theoretical calculations and thereby solving a puzzle raised by seven-year-old
measurements. Our experimental approach does not have conceptual limits,
allowing us to foresee, with the help of upcoming laser technology, ultra-high
resolution time-frequency studies from the visible to the x-ray range.Comment: 5 pages, 4 figure
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