56 research outputs found
Detection of the pairwise kinematic Sunyaev-Zel'dovich effect with BOSS DR11 and the Atacama Cosmology Telescope
We present a new measurement of the kinematic Sunyaev-Zeldovich effect using
data from the Atacama Cosmology Telescope (ACT) and the Baryon Oscillation
Spectroscopic Survey (BOSS). Using 600 square degrees of overlapping sky area,
we evaluate the mean pairwise baryon momentum associated with the positions of
50,000 bright galaxies in the BOSS DR11 Large Scale Structure catalog. A
non-zero signal arises from the large-scale motions of halos containing the
sample galaxies. The data fits an analytical signal model well, with the
optical depth to microwave photon scattering as a free parameter determining
the overall signal amplitude. We estimate the covariance matrix of the mean
pairwise momentum as a function of galaxy separation, using microwave sky
simulations, jackknife evaluation, and bootstrap estimates. The most
conservative simulation-based errors give signal-to-noise estimates between 3.6
and 4.1 for varying galaxy luminosity cuts. We discuss how the other error
determinations can lead to higher signal-to-noise values, and consider the
impact of several possible systematic errors. Estimates of the optical depth
from the average thermal Sunyaev-Zeldovich signal at the sample galaxy
positions are broadly consistent with those obtained from the mean pairwise
momentum signal.Comment: 15 pages, 8 figures, 2 table
Astrocytes mediate synapse elimination through MEGF10 and MERTK pathways
To achieve its precise neural connectivity, the developing mammalian nervous system undergoes extensive activity-dependent synapse remodeling. Recently microglial cells have been shown to be responsible for a portion of synaptic remodeling, but the remaining mechanisms remain mysterious. Here we report a new role for astrocytes in actively engulfing CNS synapses. This process helps to mediate synapse elimination, requires the Megf10 and Mertk phagocytic pathways, and is strongly dependent on neuronal activity. Developing mice deficient in both astrocyte pathways fail to normally refine their retinogeniculate connections and retain excess functional synapses. Lastly, we show that in the adult mouse brain, astrocytes continuously engulf both excitatory and inhibitory synapses. These studies reveal a novel role for astrocytes in mediating synapse elimination in the developing and adult brain, identify Megf10 and Mertk as critical players in the synapse remodeling underlying neural circuit refinement, and have important implications for understanding learning and memory as well as neurological disease processes
Methamphetamine withdrawal induces activation of CRF neurons in the brain stress system in parallel with an increased activity of cardiac sympathetic pathways.
Methamphetamine (METH) addiction is a major public health problem in some countries. There is evidence to suggest that METH use is associated with increased risk of developing cardiovascular problems. Here, we investigated the effects of chronic METH administration and withdrawal on the activation of the brain stress system and cardiac sympathetic pathways. Mice were treated with METH (2 mg/kg, i.p.) for 10 days and left to spontaneous withdraw for 7 days. The number of corticotrophin-releasing factor (CRF), c-Fos, and CRF/c-Fos neurons was measured by immunohistochemistry in the paraventricular nucleus of the hypothalamus (PVN) and the oval region of the bed nucleus of stria terminalis (ovBNST), two regions associated with cardiac sympathetic control. In parallel, levels of catechol-o-methyl-transferase (COMT), tyrosine hydroxylase (TH), and heat shock protein 27 (Hsp27) were measured in the heart. In the brain, chronic-METH treatment enhanced the number of c-Fos neurons and the CRF neurons with c-Fos signal (CRF+/c-Fos+) in PVN and ovBNST. METH withdrawal increased the number of CRF+neurons. In the heart, METH administration induced an increase in soluble (S)-COMT and membrane-bound (MB)-COMT without changes in phospho (p)-TH, Hsp27, or pHsp27. Similarly, METH withdrawal increased the expression of S- and MB-COMT. In contrast to chronic treatment, METH withdrawal enhanced levels of (p)TH and (p)Hsp27 in the heart. Overall, our results demonstrate that chronic METH administration and withdrawal activate the brain CRF systems associated with the heart sympathetic control and point towards a METH withdrawal induced activation of sympathetic pathways in the heart. Our findings provide further insight in the mechanism underlining the cardiovascular risk associated with METH use and proposes targets for its treatment
Understanding adaptation to first episode psychosis through the creation of images
This article aims to understand and explore the meaning of adaptation to First Episode Psychosis (FEP). An innovative method of data collection was used with ten participants who experienced FEP which integrated drawings of their lived experience within semi-structured interviews. The data were analysed through Interpretative Phenomenological Analysis and hermeneutic-phenomenological image analysis. Participants’ experience was captured in four superordinate themes which identified that adaptation to FEP entailed: ‘Finding out how psychosis fits into my story’, ‘Breaking free from psychosis’, ‘Fighting my way through psychosis’, and ‘Finding a new way of being ‘me’’. The participants’ path of adaptation to FEP was an interplay of pains, challenges, and gains, and there was resonance with posttraumatic growth in their accounts. This article illustrates that creating images may offer a powerful way of conveying the multifaceted aspects of adaptation to FEP and could help individuals in communicating and processing their experience
Eating behaviors, body image, perfectionism, and self-esteem in a sample of Portuguese girls
Objective: Eating disorders are an increasingly prevalent health problem among adolescent girls. It is well known that biological, psychosocial, and family-related factors interact in the development of this group of disorders. However, the mechanisms underlying the interaction between these variables are still poorly understood, especially in Portuguese adolescents. The aim of this study was to investigate the relationship between eating behaviors, body dissatisfaction, self-esteem, and perfectionism in a sample of Portuguese girls. Method: A community sample of 575 Portuguese girls attending secondary school, answered self-report questionnaires including data on weight, height, and the Portuguese versions of the Contour Figures Rating Scale, the Child and Adolescent Perfectionism Scale, the Children Eating Attitudes Test, and the Rosenberg Self-Esteem Scale. SPSS version 20.0 for Windows was used for statistical analyses. Results: High scores in the Children Eating Attitudes Test were associated with significantly higher levels of body dissatisfaction (r = 0.339), socially prescribed perfectionism (r = 0.175), self-oriented perfectionism (r = 0.211), and low self-esteem (r = -0.292) (all p < 0.001). Self-oriented perfectionism partially mediated the relation between body dissatisfaction and disordered eating behaviors. Conclusion: In this sample, dysfunctional eating behaviors appeared to correlate strongly with body dissatisfaction, low self-esteem, and perfectionism in girls. These themes should be addressed among female adolescents in the community
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The Simons Observatory: Science goals and forecasts
The Simons Observatory (SO) is a new cosmic microwave background experiment
being built on Cerro Toco in Chile, due to begin observations in the early
2020s. We describe the scientific goals of the experiment, motivate the design,
and forecast its performance. SO will measure the temperature and polarization
anisotropy of the cosmic microwave background in six frequency bands: 27, 39,
93, 145, 225 and 280 GHz. The initial configuration of SO will have three
small-aperture 0.5-m telescopes (SATs) and one large-aperture 6-m telescope
(LAT), with a total of 60,000 cryogenic bolometers. Our key science goals are
to characterize the primordial perturbations, measure the number of
relativistic species and the mass of neutrinos, test for deviations from a
cosmological constant, improve our understanding of galaxy evolution, and
constrain the duration of reionization. The SATs will target the largest
angular scales observable from Chile, mapping ~10% of the sky to a white noise
level of 2 K-arcmin in combined 93 and 145 GHz bands, to measure the
primordial tensor-to-scalar ratio, , at a target level of .
The LAT will map ~40% of the sky at arcminute angular resolution to an expected
white noise level of 6 K-arcmin in combined 93 and 145 GHz bands,
overlapping with the majority of the LSST sky region and partially with DESI.
With up to an order of magnitude lower polarization noise than maps from the
Planck satellite, the high-resolution sky maps will constrain cosmological
parameters derived from the damping tail, gravitational lensing of the
microwave background, the primordial bispectrum, and the thermal and kinematic
Sunyaev-Zel'dovich effects, and will aid in delensing the large-angle
polarization signal to measure the tensor-to-scalar ratio. The survey will also
provide a legacy catalog of 16,000 galaxy clusters and more than 20,000
extragalactic sources
The neuromagnetic correlates of self-initiated smooth pursuit eye movements and finger tracking in the absence of retinal input
Cosmological parameters from pre-Planck CMB measurements: A 2017 update
We present cosmological constraints from the combination of the full mission nine-year WMAP release and small-scale temperature data from the pre-Planck Atacama Cosmology Telescope (ACT) and South Pole Telescope (SPT) generation of instruments. This is an update of the analysis presented in Calabrese et al. [Phys. Rev. D 87, 103012 (2013)], and highlights the impact on ΛCDM cosmology of a 0.06 eV massive neutrino—which was assumed in the Planck analysis but not in the ACT/SPT analyses—and a Planck-cleaned measurement of the optical depth to reionization. We show that cosmological constraints are now strong enough that small differences in assumptions about reionization and neutrino mass give systematic differences which are clearly detectable in the data.We recommend that these updated results be used when comparing cosmological constraints from WMAP, ACT and SPT with other surveys or with current and future full-mission Planck cosmology. Cosmological parameter chains are publicly available on the NASA’s LAMBDA data archive
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