The outcome of different bargaining models: the effects on wages, employment and the employment mix

The paper analyses data on wages, employment and labour composition in the Uruguayan manufacturing sector during 1985-1999 in order to get some evidence on the effects of union action on these variables. The whole period is first studied using a model in which no assumptions on the underlying bargaining model are made. The results support the hypothesis of two different bargaining frameworks in the 80s and 90s. Therefore, a right-tomanage bargaining model is specified for the 80s and a recursive contracts model for the 90s. Union effects are such that while in the 80s the effect of trade unions were to increase wages and hence decrease employment, in the nineties they moderated wage demands in exchange of more job stability. They not only managed to have a positive direct effect on employment but also to buffer the negative effects of increased openness and demand fluctuations on employment. The existence of unions also had an impact on labour composition, favouring a higher share of non-production workers in total employment. The result can be linked to the fact that firms moved to more capital intensive – or at least more skilled labour intensivetechnologies to avoid union costs. A final finding is related to the fact that the change in the Uruguayan bargaining regime at the beginning of the 90s – by which the mandatory extension of contracts vanished – favoured a more decentralised negotiation scheme and thus ended with the homogenous impact found in the 80s, since coordination in bargaining was lost.

The impact of unions on the economic performance of firms

This study examines the impact of unionization at the industry level and of the degree of centralization in bargaining – the industry or the firm - on wages and on the economic performance of firms within the manufacturing sector in Uruguay, using a panel of establishments for the period 1988-1995. The model, estimated using the Generalized Method of Moments, used controls for the degree of exposure to international and regional competition, and a set of industry and firm characteristics. The main findings point at unionization increasing wages and employment; promoting investment due to the firms substituting labor by capital; being organized in those plants with higher rate of profits, but promoting increases in productivity and preventing profitability increases. Given the negative effect of unionization at the industry level on the rate of growth of profitability of firms, results also suggest that unions tended to organize and to be stronger in those sectors in which extra rents were higher due to monopoly power. The evidence also points at firm-level negotiations taking into account the interests of both parties – workers and managers - so that enhanced productivity and probably survival were achieved together with lower rates of wage inflation; substitution of labor by capital and lower profits.

Technology challenges for space interferometry: the option of mid-infrared integrated optics

Nulling interferometry is a technique providing high angular resolution which is the core of the space missions Darwin and the Terrestrail Planet Finder. The first objective is to reach a deep degree of starlight cancelation in the range 6 -- 20 microns, in order to observe and to characterize the signal from an Earth-like planet. Among the numerous technological challenges involved in these missions, the question of the beam combination and wavefront filtering has an important place. A single-mode integrated optics (IO) beam combiner could support both the functions of filtering and the interferometric combination, simplifying the instrumental design. Such a perspective has been explored in this work within the project Integrated Optics for Darwin (IODA), which aims at developing a first IO combiner in the mid-infrared. The solutions reviewed here to manufacture the combiner are based on infrared dielectric materials on one side, and on metallic conductive waveguides on the other side. With this work, additional inputs are offered to pursue the investigation on mid-infrared photonics devices.Comment: Accepted in Adv. in Space Researc

High resolution observations of Cen A: Yellow and red supergiants in a region of jet-induced star formation?

We present the analysis of near infrared (NIR), adaptive optics (AO) Subaru and archived HST imaging data of a region near the northern middle lobe (NML) of the Centaurus A (Cen A) jet, at a distance of $\sim15$ kpc north-east (NE) from the center of NGC5128. Low-pass filtering of the NIR images reveals strong -- $>3\sigma$ above the background mean -- signal at the expected position of the brightest star in the equivalent HST field. Statistical analysis of the NIR background noise suggests that the probability to observe $>3\sigma$ signal at the same position, in three independent measurements due to stochastic background fluctuations alone is negligible ($\leq10^{-7}\%$) and, therefore, that this signal should reflect the detection of the NIR counterparts of the brightest HST star. An extensive photometric analysis of this star yields $V-I$, visual-NIR, and NIR colors expected from a yellow supergiant (YSG) with an estimated age $\sim10^{+4}_{-3}$ Myr. Furthermore, the second and third brighter HST stars are, likely, also supergiants in Cen A, with estimated ages $\sim16^{+6}_{-3}$ Myr and $\sim25^{+15}_{-9}$ Myr, respectively. The ages of these three supergiants are in good agreement with the ages of the young massive stars that were previously found in the vicinity and are thought to have formed during the later phases of the jet-HI cloud interaction that appears to drive the star formation (SF) in the region for the past $\sim100$ Myr.Comment: 11 pages, 6 figures, 2 tables, accepted for publication in Ap

First fringes with an integrated-optics beam combiner at 10 um - A new step towards instrument miniaturization for mid-infrared interferometry

Observations at mas-resolution scales and high dynamic range hold a central place in achieving, for instance, the spectroscopic characterization of exo-Earths or the detailed mapping of their protoplanetary disc birthplace. Ground or space-based multi-aperture infrared interferometry is a promising technique to tackle these goals. But significant efforts still need to be undertaken to achieve a simplification of these instruments if we want to combine the light from a large number of telescopes. Integrated-optics appears as an alternative to the current conventional designs, especially if its use can be extended to a higher number of astronomical bands. This article reports for the first time the experimental demonstration of the feasibility of an integrated-optics approach to mid-infrared beam combination for single-mode stellar interferometry. We have fabricated a 2-telescope beam combiner prototype integrated on a substrate of chalcogenide glasses, a material transparent from 1 to 14 um. We have developed laboratory tools to characterize the modal properties and the interferometric capabilities of our device. We obtain fringes at 10 um and measure a mean contrast V=0.981 \pm 0.001 with high repeatability over one week and high stability over 5h. We show experimentally - as well as on the basis of modeling considerations - that the component has a single-mode behavior at this wavelength, which is essential to achieve high-accuracy interferometry. From previous studies, the propagation losses are estimated to 0.5 dB/cm for such components. We also discuss possible issues that may impact the interferometric contrast. The IO beam combiner performs well at 10. We also anticipate the requirement of a better matching between the numerical apertures of the component and the (de)coupling optics to optimize the total throughput. The next step foreseen is the achievement of wide-band interferograms.Comment: Accepted in A&A; 7 pages; 7 figure

Transmission measurement at 10.6 microns of Te2As3Se5 rib-waveguides on As2S3 substrate

The feasibility of chalcogenide rib waveguides working at lambda = 10.6 microns has been demonstrated. The waveguides comprised a several microns thick Te2As3Se5 film deposited by thermal evaporation on a polished As2S3 glass substrate and further etched by physical etching in Ar or CF4/O2 atmosphere. Output images at 10.6 microns and some propagation losses roughly estimated at 10dB/cm proved that the obtained structures behaved as channel waveguides with a good lateral confinement of the light. The work opens the doors to the realisation of components able to work in the mid and thermal infrared up to 20 microns and even more.Comment: The following article appeared in Vigreux-Bercovici et al., Appl. Phys. Lett. 90, 011110 (2007) and may be found at http://link.aip.org/link/?apl/90/01111

Archaeological Investigations for the Canyon Hydroelectric Project, Comal County, Texas

During January 1986, the Center for Archaeological Research from The University of Texas at San Antonio conducted a pedestrian survey along portions of a proposed Canyon Lake hydroelectric transmission line right-of-way in Comal County, Texas, for the Guadalupe-Blanco River Authority. The survey located six prehistoric sites (41 CM 160, 41 CM 161, 41 CM 162, 41 CM 163, 41 CM 164, and 41 CM 166) in the right-of-way, and one historic building complex (41 CM 165) adjacent to but well outside of the right-of-way. Recommendations were made for further testing of the prehistoric sites and background research for the historic site to determine their potential eligibility for nomination to the National Register of Historic Places and as a Texas Archeological Landmark. During April 1986, the Center conducted testing at prehistoric sites 41 CM 160, 41 CM 161, 41 CM 162, 41 CM 163, and 41 CM 164. Archival research was done for 41 CM 165. This work was done for the Guadalupe-Blanco River Authority as required by the Texas Historical Commission. All of the prehistoric sites were found to be lithic quarry sites that are deemed to have little potential for contributing significant new archaeological information. None are recommended as potentially eligible for nomination to the National Register or for Texas Archeological Landmark status. The historic site (41 CM 165) appears to have National Register potential. Further background research, building documentation, and selective testing are recommended, but not as part of this project

Inner disk clearing around the Herbig Ae star HD\,139614: Evidence for a planet-induced gap ?

Spatially resolving the inner dust cavity of the transitional disks is a key to understanding the connection between planetary formation and disk dispersal. The disk around the Herbig star HD 139614 is of particular interest since it presents a pretransitional nature with an au-sized gap, in the dust, that was spatially resolved by mid-IR interferometry. Using new NIR interferometric observations, we aim to characterize the 0.1-10~au region of the HD~139614 disk further and identify viable mechanisms for the inner disk clearing. We report the first multiwavelength radiative transfer modeling of the interferometric data acquired on HD~139614 with PIONIER, AMBER, and MIDI, complemented by Herschel/PACS photometries. We confirm a gap structure in the um-sized dust, extending from about 2.5 au to 6 au, and constrained the properties of the inner dust component: e.g., a radially increasing surface density profile, and a depletion of 10^3 relative to the outer disk. Since self-shadowing and photoevaporation appears unlikely to be responsible for the au-sized gap of HD~139614, we thus tested if dynamical clearing could be a viable mechanism using hydrodynamical simulations to predict the gaseous disk structure. Indeed, a narrow au-sized gap is expected when a single giant planet interacts with the disk. Assuming that small dust grains are well coupled to the gas, we found that a ~ 3~Mjup planet located at 4.5 au from the star could, in less than 1 Myr, reproduce most of the aspects of the dust surface density profile, while no significant depletion in gas occurred in the inner disk, in contrast to the dust. However, the dust-depleted inner disk could be explained by the expected dust filtration by the gap and the efficient dust growth/fragmentation in the inner disk regions. Our results support the hypothesis of a giant planet opening a gap and shaping the inner region of the HD~139614 disk.Comment: Version accepted in A&A, with typos corrections in the tex

Toward optimal water management in Colorado's Lower Arkansas River Valley: monitoring and modeling to enhance agriculture and environment

Edition 1.0 June 2006.Includes bibliographical references (pages 42-44).For several years, Colorado State University has been documenting flow and water quality conditions in Colorado's Lower Arkansas River Valley with the goal of providing data and models that water users and managers can use to enhance both agriculture and the environment in the Valley. Extensive measurements are being made in the field, and some previously gathered data are still undergoing analysis. Models of the irrigated stream-aquifer system are under development, calibration, and refinement. Potential strategies for improving conditions in the river valley are being formulated and investigated. Small-scale pilot testing of solutions are scheduled to begin during the summer of 2006. The results presented in this technical report are published as a benchmark to document completion of the first phase of this work. They also provide broad information in support of current decision making in the river valley and hopefully will stimulate feedback and discussion. Some of the information presented here is provisional since it is still undergoing refinement and expansion.This research was partially funded by the U.S. Department of the Interior Geological Survey and Colorado Water Resources Research Institute Project on Grant Number 01HQGR0077, Project 2002CO6B and the Colorado Agricultural Experiment Station project COL00694 entitled 'Multidisciplinary Research on Salinity Issues in the Arkansas River Valley.