Exploration of the BaSeL stellar library for 9 F-type stars COROT potential targets

The Basel Stellar Library (BaSeL models) is constituted of the merging of various synthetic stellar spectra libraries, with the purpose of giving the most comprehensive coverage of stellar parameters. It has been corrected for systematic deviations detected in respect to UBVRIJHKLM photometry at solar metallicity, and can then be considered as the state-of-the-art knowledge of the broad band content of stellar spectra. In this paper, we consider a sample of 9 F-type stars with detailed spectroscopic analysis to investigate the Basel Stellar Library in two photometric systems simultaneously, Johnson (B-V, U-B) and Stromgren (b-y, m_1, and c_1). The sample corresponds to potential targets of the central seismology programme of the COROT space experiment, which have been recently observed at OHP. The atmospheric parameters T_eff, [Fe/H], and log g obtained from the BaSeL models are compared with spectroscopic determinations as well as with results of other photometric calibrations. For a careful interpretation of the BaSeL solutions, we computed confidence regions around the best $\chi$^2-estimates and projected them on T_eff-[Fe/H], T_eff-log g, and log g-[Fe/H] diagrams. (Abridged)Comment: 16 pages, LaTeX2e; version accepted for publication in the new A&A Journal: minor changes + figures in black and white for better readabilit

Willingness to compete, gender and career choices along the whole ability distribution

We expand the scope of the literature on willingness to compete by asking how it varies with academic ability and whether and how it predicts career choices at different ability levels. The literature so far has mainly focused on career choices made by students at the top of the ability distribution, particularly in academic institutions. We experimentally elicit the willingness to compete of 1500 Swiss lower-secondary school students at all ability levels and link it to the study choice that students make upon finishing compulsory school. Our analysis of the relationship between willingness to compete and the study choice considers the full set of study options, including the options in vocational education. We find that willingness to compete predicts which study option high-ability students choose, not only among academic specializations but also among vocational careers, and, importantly, it also predicts whether low-ability boys pursue upper-secondary education upon finishing compulsory schooling. Our second main contribution is to systematically explore how willingness to compete varies with academic ability. We find that high-ability boys, but not girls, are substantially more willing to compete compared to all other children. As a consequence, the gender gap in willingness to compete is significantly lower among low-ability students than among high-ability students. Overall, our study highlights that insights from the literature on willingness to compete are relevant for a broader set of policy questions, populations and choices

Status febrilis mit Bewusstlosigkeit

Zusammenfassung: Eine zerebrale Beteiligung bei Malaria mit Plasmodium vivax ist ungewöhnlich. Diese schwere Form der Malaria ist üblicherweise durch Plasmodium falciparum bedingt. Wir berichten über eine 18-jährige Patientin aus Pakistan mit langjähriger intermittierender Fieberanamnese, welche 4Monate nach Einreise in die Schweiz erstmals an einer zerebralen Vivax-Malaria erkrankt. Die eindrückliche neurologische Symptomatik mit Amaurosis und Bewusstseinsstörung bildete sich in diesem Fall unter Therapie in wenigen Tagen zurück. Jedoch sind Todesfälle bei zerebraler Malaria durch Plasmodium vivax beschriebe

Metallicity gradients in the Sagittarius dwarf spheroidal Galaxy

Metallicity gradients in the Sagittarius dwarf Galaxy (Sgr) are investigated by using infrared photometric data from the 2MASS survey. To search for metallicity effects, the giant branch in a field situated near the Center of the Sgr is compared to the giant branch in a field situated near its southern edge. The contamination of Sgr giant branch by foreground Galactic stars is canceled by statistical subtraction of diagrams symmetrical in Galactic latitude. After subtraction it is possible to reconstruct the Sgr giant branch with excellent accuracy. The giant branch in the two fields have similar slopes but are shifted in color. Even after correction for the differential reddening between the fields, the shift in color between the branch remains, and is very significant. This variation in the color of the giant branch corresponds to a metallicity variation of about -0.25 Dex. The existence of a metallicity gradient in Sgr may indicate that there are two different stellar population in Sgr. One has low metallicity, and another one of higher metallicity has a smaller spatial extension.Comment: 7 pages, 8 figures, A&A in pres

A Study of Effective Soil Compaction Control of Granular Soils

Although it is known that impact compaction tests are not appropriate for granular soils, these tests continue to be widely used. Excessive settlements frequently occur in granular soils where specified field compaction is based on Standard Proctor (ASTM D 698; AASHTO T 99) maximum dry unit weights. A laboratory test program evaluated alternative test methods for granular soil compaction control and showed that a Vibrating Hammer method (similar to British Standard BS 1377:1975, Test 14) has great promise for laboratory compaction of these soils. A One-Point Vibrating Hammer test on an oven-dry soil sample is able to provide the maximum dry unit weight and water content range for effective field compaction of most granular soils. The maximum dry unit weight obtained is comparable to that from other current methods such as the Vibrating Table test (ASTM D 4253) and the Modified Proctor test (ASTM D 1557), and is greater than that from the Standard Proctor test (ASTM D 698). The method is applicable to a broader range of soils than current vibratory table compaction tests (up to 35 percent non-plastic fines and up to 15 percent plastic fines). The equipment is relatively inexpensive and is portable enough to be taken into the field. The test is easier and quicker to perform than the other methods mentioned above and provides reproducible and consistent results. Large sized granular soils/aggregates create potential problems for compaction control methods due to the presence of oversize particles. Oversize particles defined here are those retained on a 3/4-inch (19-mm) sieve. INDOT Specification 202.34 (b) 2 requiring correction of densities from laboratory compaction tests on soils with oversized particles is not being used in practice. It is not being followed primarily because guidance is not provided. As a result, the values of maximum dry unit weight from standard compaction tests will be significantly lower than those corrected for oversized particles. This finding may be the biggest reason why granular fills with oversized particles are under- performing. The proposed Vibrating Hammer Method of Compaction specifically addresses the influence of oversize particles. Based on the results from this research, a draft ASTM Standard for the Vibrating Hammer Method of Compaction has been written, is well into the balloting process, and should become an ASTM Standard Method of Test in late 2007 or early 2008. It is included in Appendix A. This report also introduces a simple calibration procedure to verify that the vibrating hammer is supplying sufficient energy to the soil. The Vibrating Hammer Method of Compaction is an alternative method for specifying maximum dry unit weights for granular soils. The method also establishes a water content range for field compaction. This research expands the applicable range of granular soils to those containing oversize particles. An experimental program, along with review of previous compaction research, was carried out to determine the effect of oversize particles on compaction performance. Testing was performed in two sizes of compaction molds, 6- inch and 11-inch, in determining this effect. An oversize correction method was considered for water content and dry density when performing a test in a 6-inch mold with scalping, i.e. removal of oversize particles. Results of an INDOT pilot implementation project used to determine the viability of using the Vibrating Hammer for field compaction are reported. Results indicate that the Vibrating Hammer method is sufficient for use with oversize particles and that maximum dry unit weights may occur at or near saturation

Bayesian multi-model projection of climate: bias assumptions and interannual variability

Current climate change projections are based on comprehensive multi-model ensembles of global and regional climate simulations. Application of this information to impact studies requires a combined probabilistic estimate taking into account the different models and their performance under current climatic conditions. Here we present a Bayesian statistical model for the distribution of seasonal mean surface temperatures for control and scenario periods. The model combines observational data for the control period with the output of regional climate models (RCMs) driven by different global climate models (GCMs). The proposed Bayesian methodology addresses seasonal mean temperatures and considers both changes in mean temperature and interannual variability. In addition, unlike previous studies, our methodology explicitly considers model biases that are allowed to be time-dependent (i.e. change between control and scenario period). More specifically, the model considers additive and multiplicative model biases for each RCM and introduces two plausible assumptions ("constant bias” and "constant relationship”) about extrapolating the biases from the control to the scenario period. The resulting identifiability problem is resolved by using informative priors for the bias changes. A sensitivity analysis illustrates the role of the informative prior. As an example, we present results for Alpine winter and summer temperatures for control (1961-1990) and scenario periods (2071-2100) under the SRES A2 greenhouse gas scenario. For winter, both bias assumptions yield a comparable mean warming of 3.5-3.6°C. For summer, the two different assumptions have a strong influence on the probabilistic prediction of mean warming, which amounts to 5.4°C and 3.4°C for the "constant bias” and "constant relation” assumptions, respectively. Analysis shows that the underlying reason for this large uncertainty is due to the overestimation of summer interannual variability in all models considered. Our results show the necessity to consider potential bias changes when projecting climate under an emission scenario. Further work is needed to determine how bias information can be exploited for this tas

Complications and treatment errors in implant positioning in the aesthetic zone: Diagnosis and possible solutions.

Incorrect implant positioning can lead to functional and aesthetic compromise. Implant positioning errors can occur in three dimensions: mesiodistal, corono-apical, and orofacial. Treatment solutions to manage adverse outcomes through positioning errors require an understanding of the underlying conditions and of those factors that may have led to the error being committed in the first place. These types of complications usually occur because of human factors. If errors do occur with adverse aesthetic outcomes, they are difficult and sometimes impossible to correct. Connective tissue grafts to reverse recession defects are only feasible in defined situations. The option to remove and replace the implant may be the only recourse, provided the removal process does not further compromise the site. Error in judgment by the clinician