Demographic Change and the Structure of Wages: A Demand-Theoretic Analysis for Brazil

With rapidly declining fertility and increased longevity the age structure of the labor force in developing countries has changed rapidly. Changing relative supply of workers by age group, and by educational attainment, can have profound effects on labor costs. Their impacts on earnings have been heavily studied in the United States but have received little attention in Asia and Latin America, where supply shocks are at least as large and have often proceeded less evenly across the economy. We use data on 502 local Brazilian labor markets from Censuses 1970-2000 to examine the extent of substitution among demographic groups as relative supply has changed. The results suggest that age-education groups are imperfect substitutes, so that larger age-education cohorts see depressed wage rates, particularly among more-educated groups. The extent of substitution has increased over time, so that the decreasing size of the least-skilled labor force today is barely raising its remaining members' wages.

Current Topics in Children's Learning and Cognition

Learning in Cognitive Niches / Gerhardt, Ana Flávia Lopes Magela -- Using the Dynamics of a Person-Context System to Describe Children’s Understanding of Air Pressure / Steen, Steffie Van der; Steenbeek, Henderien; Geert, Paul Van -- Preschoolers Learning Science: Myth or Reality? / Kloos, Heidi; Baker, Heather; Luken, Eleanor; Brown, Rhonda; Pfeiffer, David; Carr, Victoria -- The Emergence of Scientific Reasoning / Morris, Bradley J.; Croker, Steve; Masnick, Amy M.; Zimmerman, Corinne -- Cognition and the Child Witness : Understanding the Impact of Cognitive Development in Forensic Contexts / Segovia, Daisy A.; Crossman, Angela M. -- Beyond the Black-and-White of Autism : How Cognitive Performance Varies with Context / Amaral, Joseph L.; Collins, Susan; Bohache, Kevin T.; Kloos, Heidi -- Psychological Fitness in Young Adult Video Game Players / Pokorski, Mieczyslaw; Borecki, Lukasz; Jernajczyk, Urszula -- The Impact of Moving Away from Home on Undergraduate Metacognitive Development / Downing, KevinAs a whole, the essays in this book address theoretical and empirical issues related to children's learning and cognition. The first essay, titled Learning in Cognitive Niches, treats the process of sense making on a theoretical level, discussing the complexity of factors that give rise to children's learning. It is followed by an essay, titled Using the Dynamics of a Person-Context System to Describe Children's Understanding of Air Pressure, that applies ideas from complexity science and dynamics-systems theory to children's learning about science. The next four essays summarize and synthesize already published findings, in an effort to go beyond individual viewpoints and present a more nuanced picture of children's sense making. In particular, two of these summaries, Preschoolers Learning Science: Myth or Reality? and The Emergence of Scientific Reasoning, focus on children's ability to make sense of their physical environment. The essay Cognition and the Child Witness: Understanding the Impact of Cognitive Development in Forensic Contexts seeks to shed light on children's sense making relevant to forensic issues. And the essay Beyond the Black-and-White of Autism: How Cognitive Performance Varies with Context ventures in the area of autism, a disorder that demonstrates atypical processes of combining pieces of information. The final two essays provide original data to add to the discussion of what factors affect cognitive functioning. In particular, the essay Cognitive Fitness in Young Adult Video Game Players seeks to re-assess the often-assumed relation between video gaming and various aspects of thinking, memory, intelligence, and visual-spatial abilities. And the essay Impact of Moving Away from Home on Undergraduate Metacognitive Development explicitly connects life circumstances to the ability to monitor and control one's thinking. Together, the collection of essays are a further step towards understanding the process of sense making as children and young adults interact with their environment

The threats endangering Australia's at-risk fauna

Reducing the rate of species extinctions is one of the great challenges of our time. Understanding patterns in the distribution and frequency of both threatened species and the threatening processes affecting them improves our ability to mitigate threats and prioritize management actions. In this quantitative synthesis of processes threatening Australian at-risk fauna, we find that species are impacted by a median of six threats (range 1–19), though there is considerable variation in numbers of threats among major taxonomic groups. Invasive species, habitat loss, biological resource use, natural systems modification and climate change are the processes most commonly affecting Australian threatened species. We identified an uneven distribution of research knowledge among species, with half of the total number of species-specific peer-reviewed scientific publications associated with only 11 threatened species (2.7%). Furthermore, the number of threats associated with each species was correlated with the research effort for that species, and research effort was correlated with body mass. Hence, there appears to be a research bias towards larger-bodied species, and certain charismatic species, that could result in inferences biased towards these favored species. However, after accounting for these effects we found that for birds, amphibians, reptiles and marine mammals body mass is positively correlated with the number of threats associated with each species. Many threats also co-occur, indicating that threat syndromes may be common

The prevalence of common skin infections in four districts in Timor-Leste: a cross sectional survey

Background\ud Skin infections are a common public health problem in developing countries; however, they are rarely managed using a population based approach. Recent data on the burden of skin infections in Timor-Leste are limited. Our survey appears to be the only widespread survey conducted in more than 30 years and was designed to determine the baseline prevalence of some common skin infections in Timor-Leste.\ud \ud Methods\ud We conducted a cross sectional survey in 14 sites including community health clinics, schools and hospitals within four different geographical regions. Participants were examined for five conditions (scabies, pyoderma, fungal infections, leprosy and yaws) by a multidisciplinary team. Analyses were conducted using EpiInfo version 6.04d.\ud \ud Results\ud We examined the skin of 1535 participants aged between four months and 97 years. The majority of participants were male, aged between 11 and 20 years and had at least one condition of interest (56.0%, 56.0%, and 63.1%, respectively). Fungal infections were the most common presentation (39.0%) and males were more commonly affected than females (42.3% vs 34.0%, respectively, pvalue < 0.0001).\ud \ud Among those people with more than one condition the two most common co-infections were scabies with either pyoderma or a fungal infection (38.0% and 32.0%, respectively). The survey identified 29 previously undiagnosed cases of leprosy and six cases of yaws.\ud \ud Conclusions\ud Our findings indicate the need for a comprehensive programme to address these conditions. There are successful disease control programmes in place within the country and it is hoped a healthy skin programme could be integrated into an established disease control programme in order to maximise health benefits and resources

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

Measurement of the production cross section for W-bosons in association with jets in pp collisions at s=7 TeV with the ATLAS detector

This Letter reports on a first measurement of the inclusive W + jets cross section in proton-proton collisions at a centre-of-mass energy of 7 TeV at the LHC, with the ATLAS detector. Cross sections, in both the electron and muon decay modes of the W-boson, are presented as a function of jet multiplicity and of the transverse momentum of the leading and next-to-leading jets in the event. Measurements are also presented of the ratio of cross sections sigma (W + >= n)/sigma(W + >= n - 1) for inclusive jet multiplicities n = 1-4. The results, based on an integrated luminosity of 1.3 pb(-1), have been corrected for all known detector effects and are quoted in a limited and well-defined range of jet and lepton kinematics. The measured cross sections are compared to particle-level predictions based on perturbative QCD. Next-to-leading order calculations, studied here for n <= 2, are found in good agreement with the data. Leading-order multiparton event generators, normalized to the NNLO total cross section, describe the data well for all measured jet multiplicitie

Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≥20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≤{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration