A Cohort Analysis of Labor Participation in Mexico, 1987-2009

This paper conducts a cohort analysis of labor participation in urban Mexico in recent decades. The rates analyzed are the labor force participation, the unemployment rate, and the employment shares of the formal and informal salaried sectors, as well as of self-employment. These rates are decomposed into age, cohort, and time effects. The life cycle patterns of labor force participation and formal employment follow a standard inverted U-shape. Younger workers are more likely to participate in the informal salaried sector, while self-employment increases monotonically with age. However, significant informal salaried employment is also observed among older unskilled workers and women of different ages. Strong countercyclical variations are observed for the informal salaried sector, while the opposite occurs for the formal sector. Self-employment fluctuations are for the most part acyclical. These facts support a mixed view of the labor markets whereby some informal sector workers are rationed out of the formal sector, while others go into this sector voluntarily. The analysis also indicates that the female labor force is countercyclical, suggesting the existence of an "added worker" effect. Long-run generational effects show a steadily rising participation in the informal sector with a corresponding decline in formality among newer generations of salaried workers. Some preliminary explanations for this fact are discussed.Latin America, labor force composition, informal sector

Path to Destruction: Cook County\u27s Property Tax System is a Cause for Concern as it Mimics the Defunct Taxing Procedures that Led to the Detroit Foreclosure Crisis

For decades, Cook County, Illinois, has had one of the highest property tax rates in the country, and as a result the County has begun to experience unprecedented foreclosure rates which has contributed, in part, to the State’s significant population decline. Residents are forced to endure a property tax system that disproportionately burdens low-income homeowners, while providing tax breaks to higher-income individuals and commercial owners. The primary causes and characteristics of Cook County’s defunct property tax system are strikingly similar to those that sent the City of Detroit spiraling into bankruptcy in 2013. This note provides a comparative analysis of the economic, societal, and political factors that led to the Detroit Foreclosure Crisis and how these same factors are prevalent in modern-day Cook County. Along with the various causes behind Cook County’s defective property tax system, this note explores the detrimental effects that the excessive property taxes have on low-income residents, particularly within the impoverished communities on the South Side of Chicago. Ultimately, significant changes to the property tax system are necessary to prevent Cook County from suffering the same fate as Detroit

Gas physical conditions and kinematics of the giant outflow Ou4

Ou4 is a recently discovered bipolar outflow with a projected size of more than one degree in the plane of the sky. It is apparently centred on the young stellar cluster -whose most massive representative is the triple system HR8119- inside the HII region Sh 2-129. The driving source, the nature, and the distance of Ou4 are not known. Deep narrow-band imagery of the whole nebula at arcsec resolution was obtained to study its morphology. Long-slit spectroscopy of the tips of the bipolar lobes was secured to determine the gas ionization mechanism, physical conditions, and line-of-sight velocities. An estimate of the proper motions at the tip of the south lobe using archival images is attempted. The existing multi-wavelength data for Sh 2-129 and HR 8119 are also comprehensively reviewed. The morphology of Ou4, its emission-line spatial distribution, line flux ratios, and the kinematic modelling adopting a bow-shock parabolic geometry, illustrate the expansion of a shock-excited fast collimated outflow. The radial velocities and reddening are consistent with those of Sh 2-129 and HR 8119. The improved determination of the distance to HR8119 (composed of two B0 V and one B0.5 V stars) and Sh 2-129 is 712 pc. We identify in WISE images a 5 arcmin-radius (1 pc at the distance above) bubble of emission at 22 micron emitted by hot (107 K) dust, located inside the central part of Ou4 and corresponding to several [O III] features of Ou4. The apparent position and the properties studied in this work are consistent with the hypothesis that Ou4 is located inside the Sh 2-129 HII region, suggesting that it was launched some 90 000 yrs ago by HR8119. The outflow total kinetic energy is estimated to be ~4e47~ergs. However, the alternate possibility that Ou4 is a bipolar planetary nebula, or the result of an eruptive event on a massive AGB or post-AGB star not yet identified, cannot be ruled out.Comment: Accepted for publication in Astronomy and Astrophysics. Also available at http://hal.archives-ouvertes.fr/hal-0102228

The OpenMC Monte Carlo particle transport code

A new Monte Carlo code called OpenMC is currently under development at the Massachusetts Institute of Technology as a tool for simulation on high-performance computing platforms. Given that many legacy codes do not scale well on existing and future parallel computer architectures, OpenMC has been developed from scratch with a focus on high performance scalable algorithms as well as modern software design practices. The present work describes the methods used in the OpenMC code and demonstrates the performance and accuracy of the code on a variety of problems.United States. Department of Energy (DE-AC05-00OR22725

Optimized design and performance of a shared pump single clad 2 µm TDFA

International audienceWe report the design, experimental performance, and simulation of a single stage, co-and counter-pumped Tm-doped fiber amplifier (TDFA) in the 2 μm signal wavelength band with an optimized 1567 nm shared pump source. We investigate the dependence of output power, gain, and efficiency on pump coupling ratio and signal wavelength. Small signal gains of >50 dB, an output power of 2 W, and small signal noise figures of <3.5 dB are demonstrated. Simulations of TDFA performance agree well with the experimental data. We also discuss performance tradeoffs with respect to amplifier topology for this simple and efficient TDFA

Towards conflictual narrative mechanics

We propose a five steps methodology to retrieve, reconstruct and analyse conflict related narratives in a standardized and automated way. Our methodology combines AI and network analysis techniques to build a visual representation of key agents and entities involved in a conflict and to characterize their relations. Unlike the majority of existing methods, ours can be applied to any type of conflict, as, through two data downloading phases, it first generates a bird’s-eye representation and then a fine-grained map of any conflict. Given the broad applicability of the proposed methodology, we believe that this work moves the first steps towards a better understanding of conflictual narrative mechanics

Quest for wine yeasts—An old story revisited

Numerous studies have described the yeast biota of grapes, and grape must in order to understand better the succession of yeasts during fermentation of wine. The origin of the wine yeasts has been rather controversial. By using more elaborate isolation methods, classical genetic analysis and electrophoretic karyotyping of monosporic clones, with this study, credible proof now exists that the vineyard is the primary source for the wine yeasts and that strains found on the grapes can be followed through the fermentation process

The 2022 FIFA World Cup May Be the Catalyst to Dismantle (or at Least Reform) the Kafala Labor System

On December 2, 2010, the football/soccer world was stunned when the small Middle Eastern country known as the State of Qatar (Qatar) won the rights to host the 2022 Fédération Internationale de Football Associate (FIFA) Men’s Football World Cup even though its national team had never qualified for a single FIFA World Cup competition. What made Qatar’s bid so attractive to FIFA was that it included  the building of a new airport, a commitment to updating the country’s public transportation infrastructure, the construction of $20 billion worth of new roads and highways which included a bridge to the neighboring country of Bahrain (the longest in the world), the creation of 54 training camps and the opening of a number of hotels to accommodate the spectators, teams, and broadcasting/press corps from the various countries that would be visiting the country over the 29-day contest period. Most importantly, however, Qatar also assured FIFA that it would construct no less than nine football/soccer specific stadiums, each state-of-the-art and equipped with cooling systems that would help alleviate the oppressive Qatari heat since the average temperature on the Gulf peninsula averages around 29 degrees Celsius (85 degrees Fahrenheit) but can reach as high as 45 degrees Celsius (113 degrees Fahrenheit) during the summer months