1,061 research outputs found
"Phoenix' reflectarray unit cell with reduced size and inductive loading
This study presents a new Phoenix unit cell with reduced size (l0/3 at centre frequency). Three different
techniques are investigated to preserve a complete 360° phase range, with quasi-linear and parallel phase responses
over a reasonable frequency band, in spite of this small size. The phase cycle successively uses two different printed
elements with complementary capacitive and inductive responses. The studied techniques aim at increasing the
insufficient inductive effect. As a demonstration, a 1877-element reflectarray is fabricated with the technique
compatible with a single-substrate fabrication process. Measured results show a 1 dB gain bandwidth of 11.3%.Makdissy, T.; Gillard, R.; Fourn, E.; Ferrando Rocher, M.; Girard, E.; Legay, H.; Le Coq, L. (2016). "Phoenix' reflectarray unit cell with reduced size and inductive loading. IET Microwaves Antennas and Propagation. 10(12):1363-1370. doi:10.1049/iet-map.2015.0626S13631370101
Clustering, host halos and environment of z2 galaxies as a function of their physical properties
Using a sample of 25683 star-forming and 2821 passive galaxies at ,
selected in the COSMOS field following the BzK color criterion, we study the
hosting halo mass and environment of galaxies as a function of their physical
properties. Spitzer and Herschel provide accurate SFR estimates for starburst
galaxies. We measure the auto- and cross-correlation functions of various
galaxy sub-samples and infer the properties of their hosting halos using both
an HOD model and the linear bias at large scale. We find that passive and
star-forming galaxies obey a similarly rising relation between the halo and
stellar mass. The mean host halo mass of star forming galaxies increases with
the star formation rate between 30 and 200 M.yr, but flattens
for higher values, except if we select only main-sequence galaxies. This
reflects the expected transition from a regime of secular co-evolution of the
halos and the galaxies to a regime of episodic starburst. We find similar large
scale biases for main-sequence, passive, and starburst galaxies at equal
stellar mass, suggesting that these populations live in halos of the same mass.
We detect an excess of clustering on small scales for passive galaxies and
showed, by measuring the large-scale bias of close pairs, that this excess is
caused by a small fraction () of passive galaxies being hosted by
massive halos ( M) as satellites. Finally,
extrapolating the growth of halos hosting the z2 population, we show that
M M galaxies at z2 will evolve, on average,
into massive (M M), field galaxies in the local
Universe and M M galaxies at z=2 into local,
massive, group galaxies. The most massive main-sequence galaxies and close
pairs of massive, passive galaxies end up in today's clusters.Comment: 18 pages, 16 figures, Accepted by A&
Biological and prognostic impact of apobec-induced mutations in the spectrum of plasma cell dyscrasias
In multiple myeloma (MM), whole exome sequencing (WES) studies have revealed four mutational signatures: two associated with aberrant activities of APOBEC cytidine deaminases (Signatures #2 and #13) and two clock-like signatures associated with "cancer age" (Signatures #1 and #5). Mutational signatures have not been investigated systematically in larger series, nor in other primary plasma cell dyscrasias such as monoclonal gammopathy of unknown significance (MGUS) or primary plasma cell leukemia (pPCL). Finally, while APOBEC activity has been correlated to increased mutational burden and poor-prognosis MAF/MAFB translocations in MM at diagnosis, this has never been confirmed in multivariate analysis in an independent series.
To answer these questions, we mined 1151 MM samples from public WES datasets, including samples from the IA9 public release of the CoMMpass trial. The CoMMpass data were generated as part of the Multiple Myeloma Research Foundation Personalized Medicine Initiatives. We also analyzed 6 MGUS/Smoldering MM as well as 5 previously published pPCLs. Extraction of mutational signatures was performed using the NNMF algorithm as previously described (Alexandrov et al. Nature 2013).
NNMF in the whole cohort extracted the known 4 signatures pertaining to distinct mutational processes: the two clock-like processes (signatures #1 and #5) and aberrant APOBEC deaminase activity (signatures #2 and #13). While the clock-like processes were more prominent in the cohort as a whole (median 70%, range 0-100%), the APOBEC showed a heterogeneous contribution, more visible in samples with the highest mutation burden. In fact, the absolute and relative contribution of APOBEC activity to the mutational repertoire correlated with the overall number of mutations (r=0.71, p= < 0.0001). As previously described, APOBEC contribution was significantly enriched among MM patients with t(14;16) and with t(14;20) (p<0.001), but the association between relative APOBEC contribution and mutational load remained significant across all cytogenetic subgroups with the exception of t(11;14). In the MGUS/SMM series, APOBEC contribution was generally low. Conversely, APOBEC activity was preponderant in three out of five pPCL samples, all of them characterized by the t(14;16)( IGH / MAF); in the remaining two pPCL the absolute number of APOBEC mutations was similar to MM. Overall, the APOBEC contribution was characterized by a progressive increment from MGUS/SMM to MM and pPCL.
We next went on to investigate the prognostic impact of APOBEC signatures at diagnosis. Patients with APOBEC contribution in the 4th quartile had shorter PFS (2-y PFS 47% vs 66%, p<0.0001) and OS (2-y OS 70% vs 85%, p=0.0033) than patients in quartiles 1-3 (Figure 1a-b). This was independent from the association of APOBEC activity with MAF translocations and higher mutational burden, as shown by multivariate analysis with Cox regression (Figure 1c-d). ISS stage III was the only other variable that retained its independent prognostic value for both PFS and OS. We therefore combined both variables and found that co-occurrence of ISS III and APOBEC 4th quartile identifies a fraction of high-risk patients with 2-y OS of 53.8% (95% CI 36.6%-79%), while their simultaneous absence identifies long term survivors with 2-y OS of 93.3% (95% CI 89.6-97.2%).
In this study, we provided a global overview on the contribution of mutational processes in the largest whole exome series of plasma cell dyscrasias investigated to date by NNMF. We propose that cases with high APOBEC activity may represent a novel prognostic subgroup that is transversal to conventional cytogenetic subgroups, advocating for closer integration of next-generation sequencing studies and clinical annotation to confirm this finding in independent series
Measurement of the cosmic ray spectrum above eV using inclined events detected with the Pierre Auger Observatory
A measurement of the cosmic-ray spectrum for energies exceeding
eV is presented, which is based on the analysis of showers
with zenith angles greater than detected with the Pierre Auger
Observatory between 1 January 2004 and 31 December 2013. The measured spectrum
confirms a flux suppression at the highest energies. Above
eV, the "ankle", the flux can be described by a power law with
index followed by
a smooth suppression region. For the energy () at which the
spectral flux has fallen to one-half of its extrapolated value in the absence
of suppression, we find
eV.Comment: Replaced with published version. Added journal reference and DO
Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory
The Auger Engineering Radio Array (AERA) is part of the Pierre Auger
Observatory and is used to detect the radio emission of cosmic-ray air showers.
These observations are compared to the data of the surface detector stations of
the Observatory, which provide well-calibrated information on the cosmic-ray
energies and arrival directions. The response of the radio stations in the 30
to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of
the incoming electric field. For the latter, the energy deposit per area is
determined from the radio pulses at each observer position and is interpolated
using a two-dimensional function that takes into account signal asymmetries due
to interference between the geomagnetic and charge-excess emission components.
The spatial integral over the signal distribution gives a direct measurement of
the energy transferred from the primary cosmic ray into radio emission in the
AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air
shower arriving perpendicularly to the geomagnetic field. This radiation energy
-- corrected for geometrical effects -- is used as a cosmic-ray energy
estimator. Performing an absolute energy calibration against the
surface-detector information, we observe that this radio-energy estimator
scales quadratically with the cosmic-ray energy as expected for coherent
emission. We find an energy resolution of the radio reconstruction of 22% for
the data set and 17% for a high-quality subset containing only events with at
least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO
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