2,601 research outputs found
The Bolsonaro Government’s 2019 pension reform in Brazil:A policy discourse analysis
In 2019, the Brazilian Government secured support to pass radical reforms to the state pension system. Drawing on concepts from historical materialist policy analysis and critical discourse analysis, this paper contributes to understanding how the Bolsonaro Government utilized narratives of inter- and intra-class and generational (in)equity to problematize constitutional guarantees of social and economic rights and warrant fiscal austerity and curtailment of social protections. We contend that the 2019 pension reform can be understood as a complementary political project to the preceding Temer Government’s labor market reforms and successful passing of legislation to place a ceiling on Federal expenditure to constrain pro-welfare politics. Our analysis adds to understanding of how policy discourse legitimated a transformation in Brazilian social policy commensurate with advancing a conservative austere-liberal market hegemony project
Instrumental Uncertainty as a Determinant of Behavior Under Interval Schedules of Reinforcement
Interval schedules of reinforcement are known to generate habitual behavior, the performance of which is less sensitive to revaluation of the earned reward and to alterations in the action-outcome contingency. Here we report results from experiments using different types of interval schedules of reinforcement in mice to assess the effect of uncertainty, in the time of reward availability, on habit formation. After limited training, lever pressing under fixed interval (FI, low interval uncertainty) or random interval schedules (RI, higher interval uncertainty) was sensitive to devaluation, but with more extended training, performance of animals trained under RI schedules became more habitual, i.e. no longer sensitive to devaluation, whereas performance of those trained under FI schedules remained goal-directed. When the press-reward contingency was reversed by omitting reward after pressing but presenting reward in the absence of pressing, lever pressing in mice previously trained under FI decreased more rapidly than that of mice trained under RI schedules. Further analysis revealed that action-reward contiguity is significantly reduced in lever pressing under RI schedules, whereas action-reward correlation is similar for the different schedules. Thus the extent of goal-directedness could vary as a function of uncertainty about the time of reward availability. We hypothesize that the reduced action-reward contiguity found in behavior generated under high uncertainty is responsible for habit formation
The Burst Alert Telescope (BAT) on the Swift MIDEX Mission
The Burst Alert Telescope (BAT) is one of 3 instruments on the Swift MIDEX
spacecraft to study gamma-ray bursts (GRBs). The BAT first detects the GRB and
localizes the burst direction to an accuracy of 1-4 arcmin within 20 sec after
the start of the event. The GRB trigger initiates an autonomous spacecraft slew
to point the two narrow field-of-view (FOV) instruments at the burst location
within 20-70 sec so to make follow-up x-ray and optical observations. The BAT
is a wide-FOV, coded-aperture instrument with a CdZnTe detector plane. The
detector plane is composed of 32,768 pieces of CdZnTe (4x4x2mm), and the
coded-aperture mask is composed of approximately 52,000 pieces of lead
(5x5x1mm) with a 1-m separation between mask and detector plane. The BAT
operates over the 15-150 keV energy range with approximately 7 keV resolution,
a sensitivity of approximately 10E-8 erg*cm^-2*s^-1, and a 1.4 sr (half-coded)
FOV. We expect to detect >100 GRBs/yr for a 2-year mission. The BAT also
performs an all-sky hard x-ray survey with a sensitivity of approximately 2
mCrab (systematic limit) and it serves as a hard x-ray transient monitor.Comment: 18 Pages, 12 Figures, To be published in Space Science Review
The Giant Branch of the Globular Cluster NGC3201
Infrared photometry has been obtained for 26 stars in the field of the globular cluster NGC 3201. For 14 of these stars, optical spectra have also been obtained. These observations show that the giant branch of this cluster possesses an intrinsic width of 0.13 mag (± 1 σ) in (V-K)_0. We conclude however, that variable reddening across the cluster with σ[E(B-V)] = 0.023 is the most likely explanation of this result. In particular, the observed intrinsic width cannot be due to a range in heavy metal abundance, since there is no star-to-star scatter in the strengths of various strong metal lines.
There is a range in G band (CH) strength at constant (V-K)_0 that correlates with CO strength: stars with weak CH also have weak CO. Comparisons with published synthetic spectra show that star-to-star variations in carbon abundance of less than a factor of 3 are sufficient to explain the range in G-band strengths. With the exception of two stars, no significant scatter was found in the strengths of the λ3883 CN band.
The position of the giant branch in the infrared C-M diagram and the strengths of metal lines in the optical spectra indicate that the overall metal abundance of NGC 3201 is comparable to those of M3, M5, and NGC 6752. This is significantly more metal-poor than the preliminary abundance determined from echelle plates by Pilachowski, Sneden, and Canterna
Willman 1 - a probable dwarf galaxy with an irregular kinematic distribution
We investigate the kinematic properties and stellar population of the
Galactic satellite Willman 1 (Wil 1) by combining Keck/DEIMOS spectroscopy with
KPNO mosaic camera imaging. Wil 1 is an ultra-low luminosity Milky Way
companion. This object lies in a region of size-luminosity space (M_V ~ -2 mag,
d ~ 38 kpc, r_half ~ 20 pc) also occupied by the Galactic satellites Bo\"otes
II and Segue 1 and 2, but no other known old stellar system. We use kinematic
and color-magnitude criteria to identify 45 stars as possible members of Wil 1.
With a systemic velocity of v_helio = -12.8 +/- 1.0 km/s, Wil 1 stars have
velocities similar to those of foreground Milky Way stars. Informed by
Monte-Carlo simulations, we identify 5 of the 45 candidate member stars as
likely foreground contaminants. We confirm a significant spread in the
abundances of the likely Wil 1 red giant branch members ([Fe/H] = -1.73 +/-
0.12 and -2.65 +/- 0.12, [Ca/Fe] = -0.4 +/- 0.18 and +0.13 +/- 0.28). This
spread supports the scenario that Wil 1 is an ultra-low luminosity dwarf galaxy
rather than a star cluster. Wil 1's innermost stars move with radial velocities
offset by 8 km/s from its outer stars and have a velocity dispersion consistent
with 0 km/s, suggesting that Wil 1 may not be in dynamical equilibrium. The
combination of the foreground contamination and unusual kinematic distribution
make it difficult to robustly determine the dark matter mass of Wil 1. As a
result, X-ray or gamma-ray observations of Wil 1 that attempt to constrain
models of particle dark matter using an equilibrium mass model are strongly
affected by the systematics in the observations presented here. We conclude
that, despite the unusual features in the Wil 1 kinematic distribution,
evidence indicates that this object is, or at least once was, a dwarf galaxy.Comment: AJ accepted version. The primary improvements are a detailed
investigation of the membership probability (Section 3.4 and new Figures 6, 7
and 8) and the revised spectroscopic [Fe/H] and [Ca/Fe] measurements of the
two brightest member stars. Conclusions are unchanged from the submitted
versio
First observations of Weddell seals foraging in sponges in Erebus Bay, Antarctica
Attaching cameras to marine mammals allows for first-hand observation of underwater behaviours that may otherwise go unseen. While studying the foraging behaviour of 26 lactating Weddell seals (Leptonychotes weddellii) in Erebus Bay during the austral spring of 2018 and 2019, we witnessed three adults and one pup investigating the cavities of Rossellidae glass sponges, with one seal visibly chewing when she removed her head from the sponge. To our knowledge, this is the first report of such behaviour. While the prey item was not identifiable, some Trematomus fish (a known Weddell seal prey) use glass sponges for shelter and in which to lay their eggs. Three of the four sponge foraging observations occurred around 13:00 (NZDT). Two of the three sponge foraging adults had higher-than-average reproductive rates, and the greatest number of previous pups of any seal in our study population, each having ten pups in 12 years. This is far higher than the study population average of three previous pups (± 2.6 SD). This novel foraging strategy may have evolved in response to changes in prey availability, and could offer an evolutionary advantage to some individuals that exploit prey resources that others may not. Our observations offer new insight into the foraging behaviours of one of the world’s most studied marine mammals. Further research on the social aspects of Weddell seal behaviour may increase our understanding of the extent and mechanisms of behavioural transfer between conspecifics. Research into the specific foraging behaviour of especially successful or experienced breeders is also warranted
Correlations Between Lag, Luminosity, and Duration in Gamma-ray Burst Pulses
We derive a new peak lag vs. peak luminosity relation in gamma-ray burst
(GRB) pulses. We demonstrate conclusively that GRB spectral lags are pulse
rather than burst properties and show how the lag vs. luminosity relation
determined from CCF measurements of burst properties is essentially just a
rough measure of this newly derived relation for individual pulses. We further
show that most GRB pulses have correlated properties: short-lag pulses have
shorter durations, are more luminous, and are harder within a burst than
long-lag pulses. We also uncover a new pulse duration vs. pulse peak luminosity
relation, and indicate that long-lag pulses often precede short-lag pulses.
Although most pulse behaviors are supportive of internal shocks (including
long-lag pulses), we identify some pulse shapes that could result from external
shocks.Comment: 14 pages, 4 figures, 1 table; accepted for publication in
Astrophysical Journal Letter
Is albumin gradient or fluid to serum albumin ratio better than the pleural fluid lactate dehydroginase in the diagnostic of separation of pleural effusion?
BACKGROUND: To determine the accuracy of serum-effusion albumin gradient (SEAG) and pleural fluid to serum albumin ratio (ALBR) in the diagnostic separation of pleural effusion into transudate and exudate and to compare SEAG and ALBR with pleural fluid LDH (FLDH) the most widely used test. METHODS: Data collected from 200 consecutive patients with a known cause of pleural effusion in a United Kingdom district general hospital. RESULTS: The median and inter quartile ranges (IQR) for SEAG 93.5 (33.8 to 122.5) g/dl, ALBR 0.49 (0.42 to 0.62) and FLDH 98.5 IU/L(76.8 to 127.5) in transudates were significantly lower than the corresponding values for exudates 308.5 (171 to 692), 0.77 (0.63 to 0.85), 344 (216 to 695) all p < 0.0001. The Area Under the Curve (AUC) with 95% confidence intervals (Cl) for SEAG, ALBR and FLDH were 0.81 (0.75 to 0.87), 0.79 (0.72 to 0.86) and 0.9 (0.87 to 0.96) respectively. The positive likelihood ratios with 95%CI for FLDH, SEAG, and ALBR were: 7.3(3.5–17), 6.3(3–15) 6.2(3–14) respectively. There was a significant negative correlation between SEAG and ALBR (r= -0.89, p < 0.0001). CONCLUSION: The discriminative value for SEAG and ALBR appears to be similar in the diagnostic separation of transudates and exudates. FLDH is a superior test compared to SEAG and ALBR
AI reflections in 2020
We invited authors of selected Comments and Perspectives published in Nature Machine Intelligence in the latter half of 2019 and first half of 2020 to describe how their topic has developed, what their thoughts are about the challenges of 2020, and what they look forward to in 2021.Postprint (author's final draft
Cost-effectiveness of a community-delivered multicomponent intervention compared with enhanced standard care of obese adolescents: cost-utility analysis alongside a randomised controlled trial (the HELP trial)
Objective To undertake a cost-utility analysis of a motivational multicomponent lifestyle-modification intervention in a community setting (the Healthy Eating
Lifestyle Programme (HELP)) compared with enhanced standard care.
Design Cost-utility analysis alongside a randomised controlled trial. Setting Community settings in Greater London, England. Participants 174 young people with obesity aged 12–19 years. Interventions Intervention participants received 12 one to-one sessions across 6months, addressing lifestyle behaviours and focusing on motivation to change and self esteem
rather than weight change, delivered by trained graduate health workers in community settings. Control participants received a single 1-hour one-to-one nurse delivered
session providing didactic weight-management
advice. Main outcome measures Mean costs and quality adjusted life years (QALYs) per participant over a 1-year period using resource use data and utility values collected during the trial. Incremental cost-effectiveness ratio (ICER) was calculated and non-parametric bootstrapping was conducted to generate a cost-effectiveness acceptability curve (CEAC).
Results Mean intervention costs per participant were £918 for HELP and £68 for enhanced standard care. There were no significant differences between the two
groups in mean resource use per participant for any type of healthcare contact. Adjusted costs were significantly higher in the intervention group (mean incremental costs
for HELP vs enhanced standard care £1003 (95% CI £837 to £1168)). There were no differences in adjusted QALYs between groups (mean QALYs gained 0.008 (95% CI −0.031 to 0.046)). The ICER of the HELP versus enhanced standard care was £120 630 per QALY gained. The CEAC shows that the probability that HELP was cost-effective relative to the enhanced standard care was 0.002 or 0.046, at a threshold of £20 000 or £30 000 per QALY gained.
Conclusions We did not find evidence that HELP was more effective than a single educational session in improving quality of life in a sample of adolescents with
obesity. HELP was associated with higher costs, mainly due to the extra costs of delivering the intervention and therefore is not cost-effective
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