1,142 research outputs found
What Does it Take to Achieve Equality of Opportunity in Education ? An Empirical Investigation Based on Brazilian Data
Roemer s’ 1998 seminal work on equality of opportunity has contributed to the emergence of a theory of justice that is modern, conceptually clear and easy to mobilize in policy design. In this paper, we apply Roemer’s theory to education policy. We first analyze the reallocations of educational expenditure required to equalize opportunities (taken to be test scores close to the end of compulsory education). Using Brazilian data, we find that implementing an equal-opportunity policy across pupils of different socio-economic background, by using per-pupil spending as the instrucment, and ensuring that nobody receives less that 1/3 of the current national average, requires multiplying by 8.6 the current level of spending on the lowest achieving pupils. This result is driven by the extremely low elasticity of scores to per-pupil spending. As such, it implies large reallocations that are probably politically unacceptable. By exploiting our knowledge of the education production function, we then identify ways of reducing financial reallocations needed to achieve equality of opportunity. We show that the simultaneous redistribution of monetary and non-moneary inputs, like peer group quality (i.e. desegregation) and school effectiveness (i.e. equalizing access to the best-run schools), considerably reduces - by almost 50% - the magnitude of financial redistribution needed. Implementing an EOp policy would not come at any particular cost (or benefit) in terms of efficiencyEquality of Opportunity; Education; Formula Funding
Using Firm-Level Data to Assess Gender Wage Discrimination in the Belgian Labour Market
In this paper we explore a matched employer-employee data set to investigate the presence of gender wage discrimination in the Belgian private economy labour market. We identify and measure gender wage discrimination from firm-level data using a labour index decomposition pioneered by Hellerstein and Neumark (1995), which allows us to compare direct estimates of a gender productivity differential with those of a gender labour costs differential. We take advantage of the panel structure of the data set and identify gender wage discrimination from within-firm variation. Moreover, inspired by recent developments in the production function estimation literature, we address the problem of endogeneity in input choice using a structural production function estimator (Levinsohn and Petrin, 2003). Our results suggest that there is no gender wage discrimination inside private firms located in Belgium.labour productivity; wages; gender discrimination; structural production function estimation; panel data
Nationwide population-based cohort study of uterine rupture in Belgium : results from the Belgian Obstetric Surveillance System
Objectives: We aimed to assess the prevalence of uterine rupture in Belgium and to evaluate risk factors, management and outcomes for mother and child.
Design: Nationwide population-based prospective cohort study.
Setting: Emergency obstetric care. Participation of 97% of maternity units covering 98.6% of the deliveries in Belgium.
Participants: All women with uterine rupture in Belgium between January 2012 and December 2013. 8 women were excluded because data collection forms were not returned.
Results: Data on 90 cases of confirmed uterine rupture were obtained, of which 73 had a previous Caesarean section (CS), representing an estimated prevalence of 3.6 (95% CI 2.9 to 4.4) per 10000 deliveries overall and of 27 (95% CI 21 to 33) and 0.7 (95% CI 0.4 to 1.2) per 10000 deliveries in women with and without previous CS, respectively. Rupture occurred during trial of labour after caesarean section (TOLAC) in 57 women (81.4%, 95% CI 68% to 88%), with a high rate of augmented (38.5%) and induced (29.8%) labour. All patients who underwent induction of labour had an unfavourable cervix at start of induction (Bishop Score 7 in 100%). Other uterine surgery was reported in the history of 22 cases (24%, 95% CI 17% to 34%), including 1 case of myomectomy, 3 cases of salpingectomy and 2 cases of hysteroscopic resection of a uterine septum. 14 cases ruptured in the absence of labour (15.6%, 95% CI 9.5% to 24.7%). No mothers died; 8 required hysterectomy (8.9%, 95% CI 4.6% to 16.6%). There were 10 perinatal deaths (perinatal mortality rate 117/1000 births, 95% CI 60 to 203) and perinatal asphyxia was observed in 29 infants (34.5%, 95% CI 25.2% to 45.1%).
Conclusions: The prevalence of uterine rupture in Belgium is similar to that in other Western countries. There is scope for improvement through the implementation of nationally adopted guidelines on TOLAC, to prevent use of unsafe procedures, and thereby reduce avoidable morbidity and mortality
Theoretical study of scattering in graphene ribbons in the presence of structural and atomistic edge roughness
We investigate the diffusive electron-transport properties of charge-doped
graphene ribbons and nanoribbons with imperfect edges. We consider different
regimes of edge scattering, ranging from wide graphene ribbons with (partially)
diffusive edge scattering to ribbons with large width variations and
nanoribbons with atomistic edge roughness. For the latter, we introduce an
approach based on pseudopotentials, allowing for an atomistic treatment of the
band structure and the scattering potential, on the self-consistent solution of
the Boltzmann transport equation within the relaxation-time approximation and
taking into account the edge-roughness properties and statistics. The resulting
resistivity depends strongly on the ribbon orientation, with zigzag (armchair)
ribbons showing the smallest (largest) resistivity and intermediate ribbon
orientations exhibiting intermediate resistivity values. The results also show
clear resistivity peaks, corresponding to peaks in the density of states due to
the confinement-induced subband quantization, except for armchair-edge ribbons
that show a very strong width dependence because of their claromatic behavior.
Furthermore, we identify a strong interplay between the relative position of
the two valleys of graphene along the transport direction, the correlation
profile of the atomistic edge roughness, and the chiral valley modes, leading
to a peculiar strongly suppressed resistivity regime, most pronounced for the
zigzag orientation.Comment: 13 pages, 7 figure
Generalized phonon-assisted Zener tunneling in indirect semiconductors with non-uniform electric fields : a rigorous approach
A general framework to calculate the Zener current in an indirect
semiconductor with an externally applied potential is provided. Assuming a
parabolic valence and conduction band dispersion, the semiconductor is in
equilibrium in the presence of the external field as long as the electronphonon
interaction is absent. The linear response to the electron-phonon interaction
results in a non-equilibrium system. The Zener tunneling current is calculated
from the number of electrons making the transition from valence to conduction
band per unit time. A convenient expression based on the single particle
spectral functions is provided, enabling the numerical calculation of the Zener
current under any three-dimensional potential profile. For a one dimensional
potential profile an analytical expression is obtained for the current in a
bulk semiconductor, a semiconductor under uniform field and a semiconductor
under a non-uniform field using the WKB (Wentzel-Kramers-Brillouin)
approximation. The obtained results agree with the Kane result in the low field
limit. A numerical example for abrupt p - n diodes with different doping
concentrations is given, from which it can be seen that the uniform field model
is a better approximation than the WKB model but a direct numerical treatment
is required for low bias conditions.Comment: 29 pages, 7 figure
Evaluating the adequacy of social-emotional measures in early childhood
Technical adequacy and usability are important considerations in selecting early childhood social-emotional (SE) screening and assessment measures. As identification of difficulties can be tied to programming, intervention, accountability, and funding, it is imperative that practitioners and decision makers select appropriate and quality measures from the plethora of measures available. This study systematically reviewed and evaluated the technical adequacy and usability of 10 commonly used SE assessment and screening measures, using a framework for evaluating selected properties of measures (e.g., reliability, validity). Through this review, it was found that there are inadequacies in many commonly used SE measures, deserving the attention of both users and developers
Optimal Unravellings for Feedback Control in Linear Quantum Systems
For quantum systems with linear dynamics in phase space much of classical
feedback control theory applies. However, there are some questions that are
sensible only for the quantum case, such as: given a fixed interaction between
the system and the environment what is the optimal measurement on the
environment for a particular control problem? We show that for a broad class of
optimal (state-based) control problems (the stationary
Linear-Quadratic-Gaussian class), this question is a semi-definite program.
Moreover, the answer also applies to Markovian (current-based) feedback.Comment: 5 pages. Version published by Phys. Rev. Let
Energy Harvesting from the Beating Heart by a Mass Imbalance Oscillation Generator
Energy-harvesting devices attract wide interest as power supplies of today's medical implants. Their long lifetime will spare patients from repeated surgical interventions. They also offer the opportunity to further miniaturize existing implants such as pacemakers, defibrillators or recorders of bio signals. A mass imbalance oscillation generator, which consists of a clockwork from a commercially available automatic wrist watch, was used as energy harvesting device to convert the kinetic energy from the cardiac wall motion to electrical energy. An MRI-based motion analysis of the left ventricle revealed basal regions to be energetically most favorable for the rotating unbalance of our harvester. A mathematical model was developed as a tool for optimizing the device's configuration. The model was validated by an in vitro experiment where an arm robot accelerated the harvesting device by reproducing the cardiac motion. Furthermore, in an in vivo experiment, the device was affixed onto a sheep heart for 1h. The generated power in both experiments—in vitro (30μW) and in vivo (16.7μW)—is sufficient to power modern pacemaker
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