Search results for "methods [Diffusion Tensor Imaging]"

GES: pre-main-sequence clusters [Fe/H]

2017

The radial metallicity distribution in the Galactic thin disc represents a crucial constraint for modelling disc formation and evolution. Open clusters allow us to derive both the radial metallicity distribution and its evolution over time. In this paper we perform the first investigation of the present-day radial metallicity distribution based on [Fe/H] determinations in late type members of pre-main-sequence clusters. Because of their youth, these clusters are therefore essential for tracing the current inter-stellar medium metallicity. We used the products of the Gaia-ESO Survey analysis of 12 young regions (age<100Myr), covering Galactocentric distances from 6.67 to 8.70kpc. For the fir…

VRi light curves of the lensed QSO HE 0435-1223

2011

We present VRi photometric observations of the quadruply imaged quasar HE0435-1223, carried out with the Danish 1.54m telescope at the La Silla Observatory. Our aim was to monitor and study the magnitudes and colors of each lensed component as a function of time.

ALMA third image of lensed quasar PKS 1830-211

2020

Strong gravitational lensing distorts our view of sources at cosmological distances but brings invaluable constraints on the mass content of foreground objects and on the geometry and properties of the Universe. We report the detection of a third continuum source toward the strongly lensed quasar PKS 1830-211 in ALMA multi-frequency observations of high dynamic range and high angular resolution. This third source is point-like and located slightly to the north of the diagonal joining the two main lensed images, A and B, 0.3" away from image B. It has a flux density that is 140 times weaker than images A and B and a similar spectral index, compatible with synchrotron emission. We conclude th…

2015

The combination of local orientation collinearity and spatial frequency contrast in contour integration was studied in two experiments using a 2AFC contour detection and discrimination task. Target contours were defined by local orientation collinearity, spatial frequency contrast between contour and background elements, or both cues. Experiments differed in the source of spatial frequency contrast by manipulating the spatial frequency of either contour or background elements. Cue summation gains, defined as the performance benefit of double cue conditions over single cue conditions, were evaluated and tested against the predictions derived from probability summation and linear summation. S…

Acoustic detection of neutrinos in bedrock

2019

We propose to utilize bedrock as a medium for acoustic detection of particle showers following interactions of ultra-high energy neutrinos. With the density of rock three-times larger and the speed of sound four-times larger compared to water, the amplitude of the generated bipolar pressure pulse in rock should be larger by an order of magnitude. Our preliminary simulations confirm that prediction. Higher density of rock also guarantees higher interaction rate for neutrinos. A noticeably longer attenuation length in rock reduces signal dissipation. The Pyh\"asalmi mine has a unique infrastructure and rock conditions to test this idea and, if successful, extend it to a full-size experiment.

L'évaluation socio-économique des infrastructures de transport : enrichir les approches du développement territorial

2007

International audience; Dans les années récentes, en France, le processus décisionnel en matière de grands équipements a sensiblement évolué, débouchant sur des réponses institutionnelles en termes de procédures adaptées. Ceci a eu pour conséquence d'accroître l'exigence informationnelle destinée à alimenter les débats, éclairer les problématiques abordées, leur donner un contenu le plus objectivé possible. L'une des principales thématiques systématiquement abordées dans le cadre de ces procédures participatives, est celle du développement territorial, dont l'importance en fait un des éléments essentiels de l'acceptabilité sociale. Les enseignements des observatoires socio-économiques autor…

Modélisation des objets historiques selon la fonction, l'espace et le temps pour l'étude des dynamiques urbaines dans la longue durée

2010

The proposed principle for understanding the urban fabric is based on considering the town as a set of complex objects, taking a systemic approach. The town system used to study the urban fabric over large time spans is composed of three sub-systems relating to historical objects from the level of the excavation to that of the former urban space: function (social use), space (location, surface area and morphology) and time (dating, duration and chronology). The historical object is the analytical unit of the space studied. The purposed model allows urban changes to be observed. The originality of this procedure lies in its approach whereby it is possible to start not from the mapping of a p…

Design and performance of the prototype Schwarzschild-Couder telescope camera

2022

Journal of astronomical telescopes, instruments, and systems 8(01), 014007-1 (2022). doi:10.1117/1.JATIS.8.1.014007

Live imaging of developmental processes in a living meristem of Davidia involucrata (Nyssaceae).

2014

Morphogenesis in plants is usually reconstructed by scanning electron microscopy and histology of meristematic structures. These techniques are destructive and require many samples to obtain a consecutive series of states. Unfortunately, using this methodology the absolute timing of growth and complete relative initiation of organs remain obscure. To overcome this limitation, an in vivo observational method based on Epi-Illumination Light Microscopy (ELM) was developed and tested with a male inflorescence meristem (floral unit) of the handkerchief tree Davidia involucrata Baill. (Nyssaceae). We asked whether the most basal flowers of this floral unit arise in a basipetal sequence or, altern…

Measurement of Atmospheric Neutrino Oscillations at 6–56 GeV with IceCube DeepCore

2018

We present a measurement of the atmospheric neutrino oscillation parameters using three years of data from the IceCube Neutrino Observatory. The DeepCore infill array in the center of IceCube enables the detection and reconstruction of neutrinos produced by the interaction of cosmic rays in Earth's atmosphere at energies as low as ∼5 GeV. That energy threshold permits measurements of muon neutrino disappearance, over a range of baselines up to the diameter of the Earth, probing the same range of L/Eν as long-baseline experiments but with substantially higher-energy neutrinos. This analysis uses neutrinos from the full sky with reconstructed energies from 5.6 to 56 GeV. We measure Δm322=2.31…