Effect of Fourier filters in removing periodic systematic effects from CMB data

We consider the application of high-pass Fourier filters to remove periodic systematic fluctuations from full-sky survey CMB datasets. We compare the filter performance with destriping codes commonly used to remove the effect of residual 1/f noise from timelines. As a realistic working case, we use simulations of the typical Planck scanning strategy and Planck Low Frequency Instrument noise performance, with spurious periodic fluctuations that mimic a typical thermal disturbance. We show that the application of Fourier high-pass filters in chunks always requires subsequent normalisation of induced offsets by means of destriping. For a complex signal containing all the astrophysical and instrumental components, the result obtained by applying filter and destriping in series is comparable to the result obtained by destriping only, which makes the usefulness of Fourier filters questionable for removing this kind of effects.Comment: 10 pages, 8 figures, published in Astronomy & Astrophysic

QUBIC: the Q&U Bolometric Interferometer for Cosmology. A novel way to look at the polarized Cosmic Microwave Background

In this paper we describe QUBIC, an experiment that takes up the challenge posed by the detection of primordial gravitational waves with a novel approach, that combines the sensitivity of state-of-the art bolometric detectors with the systematic effects control typical of interferometers. The so-called ``self-calibration'' is a technique deeply rooted in the interferometric nature of the instrument and allows us to clean the measured data from instrumental effects. The first module of QUBIC is a dual band instrument (150 GHz and 220 GHz) that will be deployed in Argentina during Fall 2018

More Than Just a Pretty Face. The Relationship Between Infant’s Temperament, Food Acceptance, and Mothers’ Perceptions of Their Enjoyment of Food

The goal of the present study was to determine whether mothers’ assessment of their infants’ temperament is associated with objective measures of the infant’s acceptance patterns and their judgments of the infants’ liking of a green vegetable. To this end, infants (N = 92) were video-recorded as their mothers fed them green beans. From these videos, we determined the frequency of facial distaste expressions made during the first 2 min of the feeding. Other measures included intake, maternal ratings of infants’ enjoyment of this vegetable, and temperament. Infants who scored high on the approach dimension of the temperament questionnaire were less likely to express facial expressions of distaste, consumed more food, and were perceived by their mothers as enjoying the food more. Mediation analyses revealed that ratings of enjoyment were not directly related to the child’s approach temperament, but rather the relationship between mothers’ ratings and temperament was mediated by the amount of time infants spent eating the vegetable. Regression analyses suggested that in addition to the length of time children ate, mothers’ ratings of their infants’ enjoyment was predicted by the number of squints that the infant expressed during the meal. These findings suggest that although certain aspects of children’s temperament are related to their food acceptance, mothers attend to facial expressions and time spent eating independently of these temperamental characteristics when judging their infant’s enjoyment of a food. Understanding how mothers use this information to decide which foods to feed their infants is an important area for future research

Full Sky Study of Diffuse Galactic Emission at Decimeter Wavelengths

A detailed knowledge of the Galactic radio continuum is of high interest for studies of the dynamics and structure of the Galaxy as well as for the problem of foreground removal in Cosmic Microwave Background measurements. In this work we present a full-sky study of the diffuse Galactic emission at frequencies of few GHz, where synchrotron radiation is by far the dominant component. We perform a detailed combined analysis of the extended surveys at 408, 1420 and 2326 MHz (by Haslam et al. 1982, Reich 1982, Reich & Reich, 1986 and Jonas et al. 1998, respectively). Using the technique applied by Schlegel et al. (1998) to the IRAS data, we produce destriped versions of the three maps. This allows us to construct a nearly-full-sky map of the spectral index and of the normalization factor with sub-degree angular resolution. The resulting distribution of the spectral indices has an average of beta = 2.695 and dispersion sigma_{beta} = 0.120. This is representative for the Galactic diffuse synchrotron emission, with only minor effects from free-free emission and point sources.Comment: 10 pages, 16 jpeg figures, accepted to Astronomy & Astrophysics, Comments and figure adde

The Relationship Between Infant Facial Expressions and Food Acceptance

Purpose of Review To highlight the range of methodological approaches used to objectively measure hedonic responses to taste stimuli during the first year of life and how these behavioral responses change with experience. Challenges inherent to this type of research are discussed. Recent Findings Although newborns display characteristic orofacial reactivity to four of the five basic tastes, the facial expressions made and the amount of food consumed can be modified by experience: children learn to like what they are fed. In some cases, changes in facial responses are concordant with infant consumption, whereas in other cases facial reactivity follows changes in intake. Summary Together with ingestive measurements, precise and objective measurements of orofacial reactivity provide an understanding of how early experiences shift the hedonic tone of the taste of foods, the foundation of dietary preferences

Innate and learned preferences for sweet taste during childhood

Purpose of review: In nature, carbohydrates are a source of energy often equated with sweetness, the detection of which is associated with powerful hedonic appeal. Intakes of processed carbohydrates in the form of added sugars and sugar-sweetened beverages have risen consistently among all age groups over the last two decades. In this review, we describe the biological underpinnings that drive the consumption of sweet-tasting foods among pediatric populations. Recent findings: Scientific literature suggests that children\u27s liking for all that is sweet is not solely a product of modern-day technology and advertising but reflects their basic biology. In fact, heightened preference for sweet-tasting foods and beverages during childhood is universal and evident among infants and children around the world. The liking for sweet tastes during development may have ensured the acceptance of sweet-tasting foods, such as mother\u27s milk and fruits. Moreover, recent research suggests that liking for sweets may be further promoted by the pain-reducing properties of sugars

An experimental approach to study individual differences in infants\u27 intake and satiation behaviors during bottle-feeding

Background: As a group, bottle-fed infants are at higher risk for rapid weight gain compared with breast-fed infants. However, little is known about individual differences in feeding behaviors of bottle-feeding infants, as well as maternal and infant characteristics associated with bottle-feeding outcomes. Methods: We conducted a 2-day, within-subject study of 21 formula-feeding dyads; the within-subject factor was feeding condition: mother-led (ML; mothers were given the instruction to feed their infants as they typically would) vs. infant-led (IL; the experimenter ensured feeding began when infants signaled hunger and ended when they rejected the bottle on three consecutive occasions). Intake was determined by bottle weight; feedings were video-recorded and later analyzed to determine feeding duration and types of satiation behaviors displayed. Percent difference scores were calculated for each outcome as [((ML – IL)/IL) × 100] to standardize differences among dyads. Mothers completed questionnaires of feeding styles and infant temperament. Results: On average, infants consumed ∼42% more formula during the ML- than IL-condition (p = 0.03). However, notable variation existed in difference scores for intake (range = −52.8% to 268.9%; higher scores reflect greater intake during ML than IL). Stepwise regression illustrated that greater intakes during the ML-condition were predicted by the combination of: (1) higher infant age; (2) lower levels of infant rhythmicity and adaptability; (3) higher levels of infant positive mood; and (4) lower levels of maternal restrictive and responsive feeding styles. Conclusions: This objective, experimental approach illustrated that variation in bottle-feeding outcomes is associated with characteristics of both members of the dyad

Anisotropies of the Cosmic Microwave Background

We review the present status of Cosmic Microwave Background (CMB) anisotropy observations and discuss the main related astrophysical issues, instrumental effects and data analysis techniques. We summarise the balloon-borne and ground-based experiments that, after COBE-DMR, yielded detection or significant upper limits to CMB fluctuations. A comparison of subsets of combined data indicates that the acoustic features observed today in the angular power spectrum are not dominated by undetected systematics. Pushing the accuracy of CMB anisotropy measurements to their ultimate limits represents one of the best opportunities for cosmology to develop into a precision science in the next decade. We discuss the forthcoming sub-orbital and space programs, as well as future prospects of CMB observations.Comment: 83 pages, 16 figures. Revised version, accepted by "La Rivista del Nuovo Cimento

Advanced modelling of the Planck-LFI radiometers

The Low Frequency Instrument (LFI) is a radiometer array covering the 30-70 GHz spectral range on-board the ESA Planck satellite, launched on May 14th, 2009 to observe the cosmic microwave background (CMB) with unprecedented precision. In this paper we describe the development and validation of a software model of the LFI pseudo-correlation receivers which enables to reproduce and predict all the main system parameters of interest as measured at each of the 44 LFI detectors. These include system total gain, noise temperature, band-pass response, non-linear response. The LFI Advanced RF Model (LARFM) has been constructed by using commercial software tools and data of each radiometer component as measured at single unit level. The LARFM has been successfully used to reproduce the LFI behavior observed during the LFI ground-test campaign. The model is an essential element in the database of LFI data processing center and will be available for any detailed study of radiometer behaviour during the survey.Comment: 21 pages, 15 figures, this paper is part of the Prelaunch status LFI papers published on JINST: http://www.iop.org/EJ/journal/-page=extra.proc5/jins