Fast and precise map-making for massively multi-detector CMB experiments

Future cosmic microwave background (CMB) polarisation experiments aim to measure an unprecedentedly small signal - the primordial gravity wave component of the polarisation field B-mode. To achieve this, they will analyse huge datasets, involving years worth of time-ordered data (TOD) from massively multi-detector focal planes. This creates the need for fast and precise methods to complement the M-L approach in analysis pipelines. In this paper, we investigate fast map-making methods as applied to long duration, massively multi-detector, ground-based experiments, in the context of the search for B-modes. We focus on two alternative map-making approaches: destriping and TOD filtering, comparing their performance on simulated multi-detector polarisation data. We have written an optimised, parallel destriping code, the DEStriping CARTographer DESCART, that is generalised for massive focal planes, including the potential effect of cross-correlated TOD 1/f noise. We also determine the scaling of computing time for destriping as applied to a simulated full-season data-set for a realistic experiment. We find that destriping can out-perform filtering in estimating both the large-scale E and B-mode angular power spectra. In particular, filtering can produce significant spurious B-mode power via EB mixing. Whilst this can be removed, it contributes to the variance of B-mode bandpower estimates at scales near the primordial B-mode peak. For the experimental configuration we simulate, this has an effect on the possible detection significance for primordial B-modes. Destriping is a viable alternative fast method to the full M-L approach that does not cause the problems associated with filtering, and is flexible enough to fit into both M-L and Monte-Carlo pseudo-Cl pipelines.Comment: 16 pages, 14 figures. MNRAS accepted. Typos corrected and computing time/memory requirement orders-of-magnitude numbers in section 4 replaced by precise number

Within-Session Analysis of Amphetamine-Elicited Rotation Behavior Reveals Differences between Young Adult and Middle-Aged F344/BN Rats with Partial Unilateral Striatal Dopamine Depletion

Preclinical modeling of Parkinson's disease using 6-hydroxydopamine (6-OHDA) has been valuable in developing and testing therapeutic strategies. Recent efforts have focused on modeling early stages of disease by infusing 6-OHDA into the striatum. The partial DA depletion that follows intrastriatal 6-OHDA is more variable than the near complete depletion following medial forebrain bundle infusion, and behavioral screening assays are not as well characterized in the partial lesion model. We compared relationships between amphetamine-elicited rotation behavior and DA depletion following intrastriatal 6-OHDA (12.5 μg) in 6 month vs. 18 month F344/BN rats, at 2-weeks and 6-weeks post-lesion. We compared the total number of rotations with within-session (bin-by-bin) parameters of rotation behavior as indicators of DA depletion. Striatal DA depletion was greater in the young adult than in the middle-aged rats at 2 weeks but not at 6 weeks post-lesion. The total number of rotations for the whole session and striatal DA depletion did not differ between the two age groups. Regression analysis revealed a greater relationship between within-session parameters of rotation behavior and DA depletion in the middle-aged group than in the young adult group. These results have implications for estimating DA depletion in preclinical studies using rats of different ages

Astrophysical thermonuclear functions

As theoretical knowledge and experimental verification of nuclear cross sections increases it becomes possible to refine analytic representations for nuclear reaction rates. In this paper mathematical/statistical techniques for deriving closed-form representations of thermonuclear functions are summarized and numerical results for them are given.The purpose of the paper is also to compare numerical results for approximate and closed-form representations of thermonuclear functions.Comment: 17 pages in LaTeX, 8 figures available on request from [email protected]

Excited states of the mirror nuclei, Li7 and Be7

By studying the alpha-particles emitted in the disintegration of B10 by protons it has been shown that there exists an excited state in Be7 at 434.4±4 kev which corresponds to the well-known first excited state in the mirror nucleus, Li7. Measurements on the inelastic scattering of protons in Li7 yield a value 479.0±1.0 kev for the energy of the Li7*. The existence of these mirror states adds support to the equality of the p-p and n-n interactions exclusive of electrostatic and magnetic forces. The small difference, 45±4 kev, in the excitation energies is larger than second-order electric effects and is believed to be consistent with the order of magnitude of magnetic interactions in nuclei. The splitting of the ground and excited states must arise in some specific property of the nuclear interactions. In connection with the energy determinations, a detailed discussion is given of the precise measurements of the Q-values of nuclear reactions employing high resolution analyzers, electrostatic and magnetic, in the determination of particle energies. Experimental determinations of the cross sections for B10(p,α)Be7, B10(p,α′)Be7*(γ)Be7, B10(p,p)B10, Li7(p,p)Li7, and Li7(p,p′)Li7*(γ)Li7 are given

Promoting healthy weight for all young children: a mixed methods study of child and family health nurses' perceptions of barriers and how to overcome them.

Background:Childhood obesity is a global health concern. Early intervention to help parents adopt best practice for infant feeding and physical activity is critical for maintaining healthy weight. Australian governments provide universal free primary healthcare from child and family health nurses (CFHNs) to support families with children aged up to five years and to provide evidence-based advice to parents. This paper aims to examine factors influencing the child obesity prevention practices of CFHNs and to identify opportunities to support them in promoting healthy infant growth. Methods:This mixed methods study used a survey (n = 90) and semi-structured interviews (n = 20) with CFHNs working in two local health districts in Sydney, Australia. Survey data were analysed descriptively; interview transcripts were coded and analysed iteratively. Survey and interview questions examined how CFHNs addressed healthy infant feeding practices, healthy eating, active play and limiting sedentary behaviour during routine consultations; factors influencing such practices; and how CFHNs could be best supported. Results:CFHNs frequently advised parents on breastfeeding, introducing solid foods, and techniques for settling infants. They spent less time providing advice on evidence-based formula feeding practices or encouraging physical activity in young children. Although nurses frequently weighed and measured children, they did not always use growth charts to identify those at risk of becoming overweight or obese. Nurses identified several barriers to promoting healthy weight gain in infants and young children, including limited parental recognition of overweight in their children or motivation to change diet or lifestyle; socioeconomic factors (such as the cost of healthy food); and beliefs and attitudes about infant weight and the importance of breastfeeding and physical activity amongst parents and family members. Conclusions:CFHNs require further education and support for their role in promoting optimal child growth and development, especially training in behaviour change techniques to increase parents' understanding of healthy infant weight gain. Parent information resources should be accessible and address cultural diversity. Resources should highlight the health effects of childhood overweight and obesity and emphasise the benefits of breastfeeding, appropriate formula feeding, suitable first foods, responsiveness to infant feeding cues, active play and limiting screen time

Validation of the present day annual cycle in heavy precipitation over the British Islands simulated by 14 RCMs

The representation of the annual cycle of heavy daily precipitation events across the United Kingdom within 14 regional climate models (RCMs) and the European observation data set (E-OBS) over the 1961-2000 period is investigated. We model extreme precipitation as an inhomogeneous Poisson process with a non-stationary threshold and use a sinusoidal model for the location and scale parameter of the corresponding generalized extreme value distribution and a constant shape parameter. First we fit the statistical model to the UK Met Office 5 km gridded precipitation data set (UKMO). Second the statistical model is fitted to 14 reanalysis driven 25 km resolution RCMs from the ENSEMBLES project and to E-OBS. The resulting characteristics from the RCMs and from E-OBS are compared with those from UKMO. We study the peak time of the annual cycle of the monthly return levels, the relative amplitude of their annual cycle and the relative bias of their absolute values. We show that the performance of the RCMs depends strongly on the region. The RCMs show deficits in modeling the characteristics of the annual cycle, especially in modeling its relative amplitude and mainly in Eastern England. However the peak time of the annual cycle is adequately simulated by most RCMs. E-OBS exhibits considerable biases in the absolute values of all monthly return levels, but the relative amplitude and the phase of the annual cycle of heavy precipitation are well represented. Our results imply that studies which rely on the explicit annual cycle of simulated heavy precipitation should be carefully considered

The Private Life of Environmental Treaties

The gravitational pull of environmental treaties is felt not only by states. Yet international lawyers almost exclusively focus on states to explain treaty compliance, measure treaty implementation, and assess treaty effectiveness. This essay draws attention to a phenomenon that falls outside traditional boundaries of treaty analysis: the efforts of private corporations that aim at complying with environmental treaties. Existing models of treaty implementation are inadequate to explain these direct interactions between corporations and treaties. The dominant grammar of treaty “compliance” equally fails to fit. Using a little-studied example - the UNESCO World Heritage Convention - this essay highlights the phenomenon of corporations’ aspiring to conform their behavior to environmental treaty requirements

Non-linear Dynamics in QED_3 and Non-trivial Infrared Structure

In this work we consider a coupled system of Schwinger-Dyson equations for self-energy and vertex functions in QED_3. Using the concept of a semi-amputated vertex function, we manage to decouple the vertex equation and transform it in the infrared into a non-linear differential equation of Emden-Fowler type. Its solution suggests the following picture: in the absence of infrared cut-offs there is only a trivial infrared fixed-point structure in the theory. However, the presence of masses, for either fermions or photons, changes the situation drastically, leading to a mass-dependent non-trivial infrared fixed point. In this picture a dynamical mass for the fermions is found to be generated consistently. The non-linearity of the equations gives rise to highly non-trivial constraints among the mass and effective (`running') gauge coupling, which impose lower and upper bounds on the latter for dynamical mass generation to occur. Possible implications of this to the theory of high-temperature superconductivity are briefly discussed.Comment: 29 pages LATEX, 7 eps figures incorporated, uses axodraw style. Discussion on the massless case (section 2) modified; no effect on conclusions, typos correcte