Impossible shadows and lightness constancy

The intersection between an illumination and a reflectance edge is characterised by the `ratio-invariant' property, that is the luminance ratio of the regions under different illumination remains the same. In a CRT experiment, we shaped two areas, one surrounding the other, and simulated an illumination edge dividing them in two frames of illumination. The portion of the illumina- tion edge standing on the surrounding area (labelled contextual background) was the contextual edge, while the portion standing on the enclosed area (labelled mediating background) was the mediating edge. On the mediating background, there were two patches, one per illumination frame. Observers were asked to adjust the luminance of the patch in bright illumination to equate the lightness of the other. We compared conditions in which the luminance ratio at the contextual edge could be (i) equal (possible shadow), or (ii) larger (impossible shadow) than that at the mediating edge. In addition, we manipulated the reflectance of the backgrounds. It could be higher for the contextual than for the mediating background; or, vice versa, lower for the contextual than for the mediating background. Results reveal that lightness constancy significantly increases when: (i) the luminance ratio at the contextual edge is larger than that at the mediating edge creating an impossible shadow, and (ii) the reflectance of the contextual background is lower than that of the mediating one. We interpret our results according to the albedo hypothesis, and suggest that the scission process is facilitated when the luminance ratio at the contextual edge is larger than that at the mediating edge and/or the reflectance of the including area is lower than that of the included one. This occurs even if the ratio-invariant property is violated

Local Distributional Effects of Government Cash Transfers in Chile

Despite rapid economic growth and poverty reduction, inequality in Chile has remained high and remarkably constant over the last 20 years, prompting academic and public interest in the subject. Due to data limitations, however, research on inequality in Chile has concentrated on the national and regional levels. The impact of cash subsidies to poor households on local inequality is thus not well understood. Using poverty mapping methods to asses this impact, we find heterogeneity in the effectiveness of regional and municipal governments in reducing inequality via poverty-reduction transfers, suggesting that alternative targeting regimes may complement current practice in aiding the poor.http://deepblue.lib.umich.edu/bitstream/2027.42/57252/1/wp872 .pd

Estimating Poverty for Indigenous Groups in Chile by Matching Census and Survey Data

It is widely held that indigenous Chileans experience greater rates of poverty and indigence than non-indigenous Chileans, yet the evidence to date has been based on surveys that are not representative by ethnicity. In this paper, we use poverty mapping methodologies that are typically applied to geography to develop statistically precise estimates of poverty, indigence, poverty gaps, and indigence gaps for each of the eight indigenous groups recognized by Chilean law. We find that indigenous people experience higher rates of poverty and indigence and greater depth of poverty and indigence than non-indigenous people. These results hold within individual regions, suggesting that the differential access to economic opportunities in different parts of the country cannot fully explain the results. We also find that the burden of poverty is not shared equally across indigenous groups. Instead, the Mapuche and Aymar· experience disproportionately high poverty rates. We argue that including ethnicity in criteria for identifying poor households may help policy-makers to improve antipoverty targeting.http://deepblue.lib.umich.edu/bitstream/2027.42/64360/1/wp932.pd

Estimating Poverty for Indigenous Groups in Chile by Matching Census and Survey Data

It is widely held that indigenous Chileans experience greater rates of poverty and indigence than non-indigenous Chileans, yet the evidence to date has been based on surveys that are not representative by ethnicity. In this paper, we use poverty mapping methodologies that are typically applied to geography to develop statistically precise estimates of poverty, indigence, poverty gaps, and indigence gaps for each of the eight indigenous groups recognized by Chilean law. We find that indigenous people experience higher rates of poverty and indigence and greater depth of poverty and indigence than non-indigenous people. These results hold within individual regions, suggesting that the differential access to economic opportunities in different parts of the country cannot fully explain the results. We also find that the burden of poverty is not shared equally across indigenous groups. Instead, the Mapuche and Aymará experience disproportionately high poverty rates. We argue that including ethnicity in criteria for identifying poor households may help policy-makers to improve antipoverty targeting.Poverty; Indigence; Ethnicity; Poverty Mapping; Chile

Neighbor effects in the provision of public goods in a young democracy: Evidence from China

Fiscal mimicking and yardstick competition among neighboring jurisdictions have been widely documented in developed countries with long histories of democracy. However, there is very little empirical evidence concerning these practices in developing countries with young democracies. Using a primary panel of 86 rural Chinese administrative villages that have undergone transitions to democracy over the last two decades, we show that the neighborhood effect also exists in a young democracy, albeit at a lower magnitude than in a mature democracy. Elected chairs of village committees who have served more than one term respond positively to the provision of public projects in neighboring villages by increasing both the number of public projects and the funding allocated to undertake them. In contrast, appointed party secretaries with more than one year of service are insensitive to neighbors' performance. In addition, village leaders are strategic in timing the arrival of public projects to increase the probability of re-election: In the year preceding elections, both the number and budget of public projects increase significantly. In this sense, politicians in young and old democracies behave alike.neighbors, Public goods,

Does Perceptual Belongingness Affect Lightness Constancy?

Scientists have shown that two equal grey patches may differ in lightness when belonging to different reflecting surfaces. We extend this investigation to the constancy domain. In a CRT simulation of a bipartite field of illumination, we manipulated the arrangement of twelve patches: six squares and six diamonds. Patches of the same shape could be placed: (i) all within the same illumination field; or (ii) forming a row across the illumination fields. Furthermore, we manipulated proximity between the innermost patches and the illumination edge. The patches could be (i) touching (forming an X-junction); or (ii) not touching (not forming an X-junction). Observers were asked to perform a lightness match between two additional patches, one illuminated and the other in shadow. We found better lightness constancy when the patches of the same shape formed a row across the fields, with no effect of X-junctions

Twenty-seven years follow-up of a patient with congenital retinocephalofacial vascular malformation syndrome and additional congenital malformations (Bonnet-Dechaume-Blanc syndrome or Wyburn-Mason syndrome)

<p>Abstract</p> <p>Purpose</p> <p>Follow-up of vascular changes in a patient with congenital retinocephalofacial vascular malformation syndrome.</p> <p>Methods</p> <p>MRI and cerebral angiography.</p> <p>Results</p> <p>In a 36-year-old man, magnetic resonance im aging of the skull and cerebral angiography revealed left intracranial arteriovenous malformations. Follow-up observation of 27 years revealed no essential change of retinal and cerebral arteriovenous malformations. Additional congenital deficits in this patient were described.</p> <p>Conclusion</p> <p>Patients with retinal arteriovenous malformations should be early examined with neuroradiological methods.</p

The Large Hadron–Electron Collider at the HL-LHC

Se incluye contenido parcial de los autores, (contiene más de 300 autores)The Large Hadron–Electron Collider (LHeC) is designed to move the field of deep inelastic scattering (DIS) to the energy and intensity frontier of particle physics. Exploiting energy-recovery technology, it collides a novel, intense electron beam with a proton or ion beam from the High-Luminosity Large Hadron Collider (HL-LHC). The accelerator and interaction region are designed for concurrent electron–proton and proton–proton operations. This report represents an update to the LHeC’s conceptual design report (CDR), published in 2012. It comprises new results on the parton structure of the proton and heavier nuclei, QCD dynamics, and electroweak and top-quark physics. It is shown how the LHeC will open a new chapter of nuclear particle physics by extending the accessible kinematic range of lepton–nucleus scattering by several orders of magnitude. Due to its enhanced luminosity and large energy and the cleanliness of the final hadronic states, the LHeC has a strong Higgs physics programme and its own discovery potential for new physics. Building on the 2012 CDR, this report contains a detailed updated design for the energy-recovery electron linac (ERL), including a new lattice, magnet and superconducting radio-frequency technology, and further components. Challenges of energy recovery are described, and the lower-energy, high-current, three-turn ERL facility, PERLE at Orsay, is presented, which uses the LHeC characteristics serving as a development facility for the design and operation of the LHeC. An updated detector design is presented corresponding to the acceptance, resolution, and calibration goals that arise from the Higgs and parton-density-function physics programmes. This paper also presents novel results for the Future Circular Collider in electron–hadron (FCC-eh) mode, which utilises the same ERL technology to further extend the reach of DIS to even higher centre-of-mass energies

Quantum superposition principle and generation of ultrashort optical pulses

We discuss the propagation of laser radiation through a medium of quantum prepared {\Lambda}-type atoms in order to enhance the insight into the physics of QS-PT generator suggested in Phys. Rev. A 80, 035801 (2009). We obtain analytical results which give a qualitatively corerct description of the outcoming series of ultrashort optical pulses and show that for the case of alkali vapor medium QS-PT generation may be implemented under ordinary experimental conditions