Gender differences in time allocation of poor children in Colombia

This paper studies the e§ect of credit constraints and constraints on transfers between parents and children, on di§erences in labor and schooling across children within the same household, with an application to gender. When families are unconstrained in these respects, di§erences in labor supply or education are driven by di§erences in wages or returns to education. If the family faces an imperfect capital market, the labor supply of each child is ine¢ cient, but di§erences across children are still driven by comparative advantage. However, if interfamily transfers are constrained so that parents cannot o§set inequality between their children, they will favor the human capital accumulation of the more disadvantaged child -generally the one who works more as a child. We use our theory to examine the gender gap in child labor. Using a sample of poor families in Colombia, we conÖrm our prediction among rural households, although this is less clear for urban households. The gender gap is largely explained by the wage gap between girls and boys. Moreover, families with the potential to make capital transfers to adult children (e.g. those with large animals), can compensate adult sons for their greater child labor and reduced educational attainment. In such families, as predicted, the male/female labor gap isgreater.Child labor, schooling, credit constraints.

Optimizing a Bank of Kalman Filters for Navigation Integrity

Alternative navigation is an area of research which employs a variety of sensor technologies to provide a navigation solution in Global Navigation Satellite System degraded or denied environments. The Autonomy and Navigation Technology Center at the Air Force Institute of Technology has recently developed the Autonomous and Resilient Management of All-source Sensors (ARMAS) navigation framework which utilizes an array of Kalman Filters to provide a navigation solution resilient to sensor failures. The Kalman Filter array size increases exponentially as system sensors and detectable faults are scaled up, which in turn increases the computational power required to run ARMAS in areal-world application. In an effort to engineer a real-time ARMAS system, this study developed C CPU and GPU versions to examine the performance trade-offs as system sensors and detectable faults are scaled up. Results show promise that a real-time ARMAS system can be achieved for large scale applications through parallel processing on a many-core processor architecture

Contextualizing the Cassese Report: the dictatorship that changed the United Nations human rights system and its legacy in monitoring economic, social and cultural rights

This chapter explains the key reasons underpinning the low impact of the Cassese Report on foreign aid and its relationship with human rights violations in Chile during Pinochet's dictatorship. Through the lenses of the intergovernmental decisions establishing the mandates and scope of competences of special procedures, the analysis demonstrates the absence of political will to equate the importance granted to civil and political rights with that granted to economic, social and cultural rights. The progress to mitigate this imbalance since the time of publication of the Cassese Report has been quantitative rather than qualitative. While economic, social and cultural rights have gained prominence over the years, most advances remain insufficient, especially regarding the role of business in human rights abuses. As long as the political decisions adopted within the human rights monitoring system do not implement the indivisibility of all rights, it will be very difficult to achieve substantial progress in this field

Role of Membrane GM1 on Early Neuronal Membrane Actions of Aβ During Onset of Alzheimer\u27s Disease

The ability of beta-amyloid peptide (Aβ) to disrupt the plasma membrane through formation of pores and membrane breakage has been previously described. However, the molecular determinants for these effects are largely unknown. In this study, we examined if the association and subsequent membrane perforation induced by Aβ was dependent on GM1levels. Pretreatment of hippocampal neurons with D-PDMP decreased GM1 and Aβ clustering at the membrane (Aβ fluorescent-punctas/20 μm, control = 16.2 ± 1.1 vs. D-PDMP = 6.4 ± 0.4, p \u3c 0.001). Interestingly, membrane perforation with Aβ occurred with a slower time course when the GM1 content was diminished (time to establish perforated configuration (TEPC) (min): control = 7.8 ± 2 vs. low GM1 = 12.1 ± 0.5, p \u3c 0.01), suggesting that the presence of GM1 in the membrane can modulate the distribution and the membrane perforation by Aβ. On the other hand, increasing GM1 facilitated the membrane perforation (TEPC: control = 7.8 ± 2 vs. GM1 = 6.2 ± 1 min, p \u3c 0.05). Additionally, using Cholera Toxin Subunit-B (CTB) to block the interaction of Aβ with GM1 attenuated membrane perforation significantly. Furthermore, pretreatment with CTB decreased the membrane association of Aβ (fluorescent-punctas/20 μm, Aβ: control = 14.8 ± 2.5 vs. CTB = 8 ± 1.4, p \u3c 0.05), suggesting that GM1 also plays a role in both association of Aβ with the membrane and in perforation. In addition, blockade of the Aβ association with CTB inhibited synaptotoxicity. Taken together, our results strongly suggest that membrane lipid composition can affect the ability of Aβ to associate and subsequently perforate the plasma membrane thereby modulating its neurotoxicity in hippocampal neurons

Separation of bitumen from Utah tar sands by a hot water digestion-flotation technique

Journal ArticleTar sand deposits in the state of Utah contain more than 25 billion bbl of in-place bitumen. Although 30 times smaller than the well-known Athabasca tar sands, Utah tar sands do represent a significant domestic energy resource comparable to the national crude oil reserves (31.3 billion bbl). Based upon a detailed analysis of the physical and chemical properties of both the bitumen and the sand, a hot-water separation process for Utah tar sands is currently being developed in our laboratories at the University of Utah. This process involves intense agitation of the tar sand in a hot caustic solution and subsequent separation of the bitumen by a modified froth flotation technique. Experimental results with an Asphalt Ridge, Utah, tar sand sample indicated that percent solids and caustic concentration were the two most important variables controlling the performance of the digestion stage. These variables were identified by means of an experimental factorial design, in which coefficients of separation greater than 0.90 were realized. Although preliminary in nature, the experimental evidence gathered in this investigation seems to indicate that a hot-water separation process for Utah tar sands would allow for the efficient utilization of this important energy resource

Influência do tipo de levedura e do uso de enzima pectolítica sobre a qualidade de vinhos tintos tropicais cv. Petit verdot.

Existem leveduras com atividades metabólicas variáveis, que permitem a elaboração de vinhos com características sensoriais diferentes. A região do Vale do Submédio São Francisco vem produzindo vinhos há 20 anos, mas está ainda em busca de cultivares que sejam representativas e que possibilitem a obtenção de vinhos potenciais com qualidade e tipicidade. O objetivo deste trabalho foi avaliar a influência do tipo de levedura e do uso de enzima pectolítica, em três condições, sobre a qualidade de vinhos da cv. Petit Verdot. As plantas foram instaladas em fevereiro de 2005, enxertadas sobre o porta-enxerto R110, sistema de condução em espaldeira, solo arenoso, irrigadas por gotejamento. As uvas foram colhidas em julho/2007, apresentando sólidos solúveis totais de 24,5 (ºBrix), acidez total titulável (ATT) de 8 g.L-1 em ácido tartárico, pH 3,5 e peso médio de 100 bagas de 97,6 g. A vinificação foi realizada em frascos de vidro de 20 L, utilizando-se 15 Kg de uvas para cada tratamento. As cinco leveduras testadas foram PDM, Ever rouge e Ever cru, Fermol rouge e Fermol cru. Para cada levedura, foram realizados três tratamentos: sem adição de enzima pectolítica (25 ºC, a temperatura de fermentação), com enzima adicionada a frio (10 ºC durante 24 h) para a maceração pré-fermentação, e enzima adicionada a 25 ºC, totalizando quinze tratamentos. Após a fermentação malolática, os vinhos foram analisados, apresentando variações no teor de álcool (entre 14,2 e 15 % v/v), ATT (entre 4,4 e 7,7), pH (entre 3,9 e 4,3) e índice de polifenóis totais, IPT (entre 89,7 e 101,6). A escolha do tipo de levedura e o uso de enzimas é fundamental para a obtenção de vinhos com diferentes estilos, principalmente nas condições do Vale do São Francisco, onde se busca ainda conhecer o potencial de diferentes cultivares às condições edafo-climáticas locais

Risk assessment of an offshore wind turbine and remaining useful life estimation of the power converter. Improving availability by prioritising failures with higher risk to operation

By 2014, almost 2500 offshore wind turbines were installed in Europe representing 8GW of capacity connected to the grid and, there is a growing market penetration for the next years. Offshore wind farm operators are facing many challenges related to disparate data sources utilisation for O&M logistic optimisation. Therefore, the decision-making process needs to be based on sound analysis of the wind farm information or data available. According to several technical reports operation and maintenance (O&M) cost could reach until 30% of the levelised cost of energy (LCOE). Understanding the reliability of an offshore wind turbine and the resources required to maintain it is crucial to reduce O&M costs and thus, to reduce the levelised cost of energy (LCOE). There is a need to reduce unnecessary tasks, prioritise the most urgent tasks, improve usage of vessels, crew and technicians, reduce the cost of spare parts held and schedule preventative maintenance to minimise downtime and maximise revenue. Currently, risk assessment plays an important role in the operation and maintenance (O&M) strategies of offshore wind farms. A comprehensive failure mode and effect analysis (FMEA) has been carried out to determine critical assemblies of a generic offshore wind turbine with an induction generator, three stages gearbox and monopile foundation. The main objectives of undertaking this comprehensive FMEA was to identify those failures with significant impact on the wind turbine operation and to identify or highlight areas of risk for maintainability and availability. The FMEA is validated with; widely-used data available in the public domain; Lloyd’s Register’s experience of working with wind farm operators and; Lloyd’s Register experience of working on reliability of the mechanical system of different industrial sectors for decades. The FMEA is further augmented and updated by the use of on-going measurements from operating wind farms. Yaw system, pitch system, power converter and gearbox have been identified in the FMEA as the most critical assemblies regarding risk to the turbine operation. Power converter analysis shows high failure rates and a large proportion of undetectable failures, therefore maintenance resources have been spent on fault finding with its corresponding cost. New approaches are necessary to tackle electrical or electronic failures, especially on the power converter. To improve overall reliability, a method to estimate the remaining useful life (RUL) of a fully-rated converter in a variable speed wind turbine is proposed using data commonly available for offshore wind farm operators. Studies show that the economic impact is dominated by failures related to power electronic components such as IGBTs and capacitors due to their higher repair cost. Mathematical models have been developed to correlate turbine operation variables and environmental conditions with failure root causes to define wear and maintenance actions based on the probability of failur

Quantum dissipation due to the interaction with chaotic degrees-of-freedom and the correspondence principle

Both in atomic physics and in mesoscopic physics it is sometimes interesting to consider the energy time-dependence of a parametrically-driven chaotic system. We assume an Hamiltonian ${\cal H}(Q,P;x(t))$ where $x(t)=Vt$. The velocity $V$ is slow in the classical sense but not necessarily in the quantum-mechanical sense. The crossover (in time) from ballistic to diffusive energy-spreading is studied. The associated irreversible growth of the average energy has the meaning of dissipation. It is found that a dimensionless velocity $v_{PR}$ determines the nature of the dynamics, and controls the route towards quantal-classical correspondence (QCC). A perturbative regime and a non-perturbative semiclassical regime are distinguished.Comment: 4 pages, clear presentation of the main poin