Context. Astrophysical polarized foregrounds represent the most critical challenge in cosmic microwave background (CMB) B -mode experiments, requiring multifrequency observations to constrain ...astrophysical foregrounds and isolate the CMB signal. However, recent observations indicate that foreground emission may be more complex than anticipated. Not properly accounting for these complexities during component separation can lead to a bias in the recovered tensor-to-scalar ratio. Aims. In this paper we investigate how the increased spectral resolution provided by band-splitting in bolometric interferometry (BI) through a technique called spectral imaging can help control the foreground contamination in the case of an unaccounted-for Galactic dust frequency de-correlation along the line of sight (LOS). Methods. We focused on the next-generation ground-based CMB experiment CMB-S4 and compared its anticipated sensitivity, frequency, and sky coverage with a hypothetical version of the same experiment based on BI (CMB-S4/BI). We performed a Monte Carlo analysis based on parametric component separation methods (FGBuster and Commander) and computed the likelihood of the recovered tensor-to-scalar ratio, r . Results. The main result is that spectral imaging allows us to detect systematic uncertainties on r from frequency de-correlation when this effect is not accounted for in the component separation. Conversely, an imager such as CMB-S4 would detect a biased value of r and would be unable to spot the presence of a systematic effect. We find a similar result in the reconstruction of the dust spectral index, and we show that with BI we can more precisely measure the dust spectral index when frequency de-correlation is present and not accounted for in the component separation. Conclusions. The in-band frequency resolution provided by BI allows us to identify dust LOS frequency de-correlation residuals where an imager with a similar level of performance would fail. This creates the possibility of exploiting this potential in the context of future CMB polarization experiments that will be challenged by complex foregrounds in their quest for B -mode detection.
We evaluate the ability of future cosmic microwave background (CMB) experiments to measure the power spectrum of large scale structure using quadratic estimators of the weak lensing deflection field. ...We calculate the sensitivity of upcoming CMB experiments such as BICEP, QUaD, BRAIN, ClOVER and PLANCK to the non-zero total neutrino mass M_nu indicated by current neutrino oscillation data. We find that these experiments greatly benefit from lensing extraction techniques, improving their one-sigma sensitivity to M_nu by a factor of order four. The combination of data from PLANCK and the SAMPAN mini-satellite project would lead to sigma(M_nu) = 0.1 eV, while a value as small as sigma(M_nu) = 0.035 eV is within the reach of a space mission based on bolometers with a passively cooled 3-4 m aperture telescope, representative of the most ambitious projects currently under investigation. We show that our results are robust not only considering possible difficulties in subtracting astrophysical foregrounds from the primary CMB signal but also when the minimal cosmological model (Lambda Mixed Dark Matter) is generalized in order to include a possible scalar tilt running, a constant equation of state parameter for the dark energy and/or extra relativistic degrees of freedom.
In the quest for the faint primordial B-mode polarization of the Cosmic Microwave Background, three are the key requirements for any present or future experiment: an utmost sensitivity, excellent ...control over instrumental systematic effects and over Galactic foreground contamination. Bolometric Interferometry (BI) is a novel technique that matches them all by combining the sensitivity of bolometric detectors, the control of instrumental systematics from interferometry and a software-based, tunable, in-band spectral resolution due to its ability to perform band-splitting during data analysis (spectral imaging). In this paper, we investigate how the spectral imaging capability of BI can help in detecting residual contamination in case an over-simplified model of foreground emission is assumed in the analysis. To mimic this situation, we focus on the next generation of ground-based CMB experiment, CMB-S4, and compare its anticipated sensitivities, frequency and sky coverage with a hypothetical version of the same experiment based on BI, CMB-S4/BI, assuming that lineof-sight (LOS) frequency decorrelation is present in dust emission but is not accounted for during component separation. We show results from a Monte-Carlo analysis based on a parametric component separation method (FGBuster), highlighting how BI has the potential to diagnose the presence of foreground residuals in estimates of the tensor-to-scalar ratio r in the case of unaccounted Galactic dust LOS frequency decorrelation.
SiGe integrated circuits dedicated to the readout of superconducting bolometer arrays for astrophysics have been developed since more than 10 years at APC. Whether for Cosmic Microwave Background ...(CMB) observations with the QUBIC ground-based experiment (Aumont et al. in astro-ph.IM,
2016
.
arXiv:1609.04372
) or for the Hot and Energetic Universe science theme with the X-IFU instrument on-board of the ATHENA space mission (Barret et al. in SPIE 9905, space telescopes & instrumentation 2016: UV to
γ
Ray,
2016
.
https://doi.org/10.1117/12.2232432
), several kinds of Transition Edge Sensor (TES) (Irwin and Hilton, in ENSS (ed) Cryogenic particle detection, Springer, Berlin,
2005
) arrays have been investigated. To readout such superconducting detector arrays, we use time or frequency domain multiplexers (TDM, FDM) (Prêle in JINST 10:C08015,
2016
.
https://doi.org/10.1088/1748-0221/10/08/C08015
) with Superconducting QUantum Interference Devices (SQUID). In addition to the SQUID devices, low-noise biasing and amplification are needed. These last functions can be obtained by using BiCMOS SiGe technology in an Application Specific Integrated Circuit (ASIC). ASIC technology allows integration of highly optimised circuits specifically designed for a unique application. Moreover, we could reach very low-noise and wide band amplification using SiGe bipolar transistor either at room or cryogenic temperatures (Cressler in J Phys IV 04(C6):C6-101,
1994
.
https://doi.org/10.1051/jp4:1994616
). This paper discusses the use of SiGe integrated circuits for SQUID/TES readout and gives an update of the last developments dedicated to the QUBIC telescope and to the X-IFU instrument. Both ASIC called
SQmux
128 and
AwaXe
are described showing the interest of such SiGe technology for SQUID multiplexer controls.
A superconducting quantum interference device (SQUID) is a transducer with a nonlinear flux-to-voltage transfer function. This transfer function is periodic due to the quantization of the magnetic ...flux in a weakly connected superconducting loop. Thus, a SQUID is usually used operating in a flux-locked loop (FLL) to linearize its response. However, the periodicity of the SQUID transfer function introduces a multiplicity of allowed operating points, in FLL, for given input and output values. Furthermore, this periodicity in the open loop implies that the FLL feedback could be positive or negative, depending on the operating point. To improve the stability and linearization provided by the FLL, it is crucial to be able to determine the operating point of a SQUID in an FLL. Based on simple control considerations applied to this specific periodic system, we discuss a way to understand the FLL operating point. Measurements and simulations illustrate the point. The dynamic range of the FLL and shape with flux jumps in the flux-to-voltage transfer function is also discussed.
We are developing superconducting Microwave Kinetic Inductance Detectors to operate at near infrared and optical wavelengths for astronomy. In order to efficiently meet with the requirements of ...astronomical applications, we propose to replace the interdigitated capacitor by a metal–insulator–metal capacitor which has the advantage of presenting a larger capacitance value within a much smaller space. The pixel will occupy a space of typically 100 × 85 µm which is nine times less than a typical pixel size using the interdigitated capacitor operating at the same frequency, below 2 GHz.
The University Hospitals Paris Centre Pharmacy compounds three concentrations of cyclosporine eye drops: 20mg/mL (=2%); 5mg/mL (=0.5%) and 0.5mg/mL (=0.05%). Cyclosporine A 2% drops were developed in ...1995 to prevent the rejection of high-risk cornea transplants after failure of topical steroids. The other concentrations of eye drops were developed for the treatment of various immune or inflammatory diseases of the cornea, conjunctiva and uvea. These eye drops are dispensed with a physician's prescription to hospitalized or ambulatory patients. A retrospective study over 4 years (2009-2013) was conducted to analyze the details of prescription and possible adverse events.
Dispensations made from January 1st, 2009 through December 31st, 2013 were studied, including patient age, dose of cyclosporine and practice location of prescribing physician. We also recorded the indications for cyclosporine eye drops in a sample of ambulatory patients. The analysis of local tolerability and the effect on visual comfort was based on questionnaires sent to the patients on cyclosporine 2% over a period of 2 months.
Cyclosporine eye drops prescription grew continuously from 2009 through 2013 for all concentrations. In 2013, 5,859 patients were treated, among which 3,616 patients with topical cyclosporine 2%, 1,681 patients with 0.5%, and 562 patients with 0.05%. In total, this represents 62,621 eye drops. Treated patients ranged from 1 week to 100 years old. Topical 2% cyclosporine is indicated in 61% of cases to prevent high-risk corneal graft rejection. Other indications are corneal ulcer (6%), atopic keratoconjunctivitis (5%), vernal keratoconjunctivitis (5%) and herpetic keratitis (4%). Topical 0.5% cyclosporine is prescribed primarily for dry eye syndrome (20%) and to prevent rejection of high-risk corneal transplantation (11%), to treat ocular rosacea (10%), vernal keratoconjunctivitis (10%), atopic keratoconjunctivitis (8%) and Sjögren's syndrome (7%). Topical 0.05% cyclosporine is prescribed primarily for dry eye syndrome resistant to conventional treatment (47%) and Sjögren's syndrome (21%). Local tolerability of topical cyclosporine was evaluated in 388 patients. The majority of patients (63%) did not experience any adverse effects. The main side effects are redness, burning sensation and itching.
Prescription of various formulations of topical cyclosporine is current practice for surgical indications: rejection of high-risk corneal transplantation; or medical indications: vernal or atopic keratoconjunctivitis and dry eye syndrome. Further prospective randomized studies would be necessary to validate formulations, doses and indications of cyclosporine eye drops.
Evolutions in pediatric cardiovascular surgery have allowed the treatment of a various range of cardiovascular malformations in infants. It is a difficult branch of surgery, with vital impact, which ...can also leave residual thoracic scars, possible sources for thoracomammary deformities in adults. Most thoracomammary deformities after thoracotomy are observed at puberty, when they appear as breast asymmetries. The main cause is the breast bud injured during thoracotomy. Several techniques have been suggested for breast reconstruction, but none give satisfying results. We have been practicing lipofilling since 1998 for breast reconstruction. Since 2001, we have started applying it to breast deformities. The final result is constant in time, natural, and has a good volume filler effect. We describe the fat grafting technique, an original technique, as a solution for this kind of deformities. The technique is illustrated by two clinical cases. In conclusion, fat grafting has really improved breast asymmetry due to iatrogenic deformation. Even if those cases are rare, surgeons have to know this kind of procedure. It is indeed a simple and efficient solution for those patients after childhood, with natural and long standing results.
L’évolution de la chirurgie pédiatrique cardiovasculaire a permis de traiter de nombreuses malformations cardiaques chez les enfants. C’est une branche difficile de la chirurgie, avec un impact vital majeur. Ce type de chirurgie peut également être source de cicatrice thoracique importante, potentiellement source de séquelles mammaires à l’âge adulte. La plupart de ces malformations mammaires apparaît à la puberté, quand apparaît une asymétrie mammaire, secondaire à l’atteinte du bourgeon mammaire. Plusieurs techniques de reconstruction ont été utilisées, avec plus récemment l’utilisation du lipofilling. Nous pratiquons le lipofilling depuis 1998, d’abord en reconstruction mammaire, puis depuis 2001 aux malformations mammaires. Les résultats sont naturels, durables et la consistance est proche de celle d’un sein normal. La technique est illustrée au travers de deux cas cliniques. En conclusion, le lipofilling a permis d’améliorer considérablement les déformations mammaires iatrogènes liées à la chirurgie cardiaque dans l’enfance. Il nous a semblé intéressant de diffuser la technique permettant d’obtenir un résultat naturel et durable. Le transfert graisseux est une solution simple pour l’asymétrie mammaire gênante de l’adolescente.
Once that the focal plane of the HFI instrument of the Planck mission (launched in May 2009) has reached operational temperature, we have observed the thermal effect of cosmic ray interaction with ...the Planck satellite, located at Lagrangian point L2. When a particle hits a component of the bolometers (e.g.: thermometer, grid or wafer) composing the focal plane of HFI, a thermal spike (called glitch), due to deposited energy, is observed. Processing these data revealed another effect due to high energy cosmic ray particle showers: High Coincidence Events (HCE), composed of glitches occurring coincidentally in many detectors and with a temperature increase from nK to
μ
K after the shower. A flux of about 100 HCE per hour has been calculated. Two types of HCE have been detected: fast and slow. For the first type, the untouched bolometers reach the same temperature as the touched ones in a few seconds which can be explained by a storage of the deposited energy in the stainless steel focal plane. The second type of HCE is not fully understood yet. These effects might be explained by extra conduction from the helium released from cryogenic surfaces, creating a temporary thermal link between the different stages of the HFI.
We report on the performance of a superconducting NbSi transition edge sensor (TES), which is co-evaporated on a suspended SiO/SiN/SiO trilayer membrane. The temperature sensitivity coefficient (α) ...calculated from the measured resistive transition curve is as high as 200. The current-voltage characteristics were measured at bath temperatures varying from 288 mK to 440 mK using a two-stage SQUID amplifier, from which the thermal conductance (G) was found to be 345 pW/K. We also measured the current noise at different bias voltages at 288 mK. The obtained electrical noise equivalent power (NEP) from its calculated current responsivity and measured current noise is about 8 × 10 -17 W/√Hz. In addition, the preliminary measurement results of time domain multiplexing scheme based on the superconducting quantum interference devices (SQUIDs) and an application specific integrated circuit (ASIC) are presented.
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