Quasilinear and singular elliptic systems

In this paper, we investigate a general quasilinear elliptic and singular system. By monotonicity methods, we give some existence and uniqueness results. Next, we give some applications to biological models

Diversity of human capital attributes and diversity of remunerations

The purpose is to provide some empirical evidence for promoting new insights into the economics of education. Particular attention is paid to the concept of competence and its influence on employee reward. The paper aims at comparing the impact on fixed earnings and flexible pay of the traditional human capital theory variables (education and experience) on the one hand and of specifically identified and assessed competences, on the other hand. The objective is to test if the HCV (years of schooling, years of labour market experience) and competences substitute or complement each other in the definition of earnings.Human Capital ; Remunerations ; Fixed earnings ; Flexible pay ; Education ; Professional Experience ; Competencies

Diversity of human capital attributes and diversity of remunerating systems

This paper aims at comparing the respective impact of the traditional Human Capital Variables (HCV) and of competences explicitly assessed on employees' remuneration. The data are derived from an original survey conducted in five large banking companies in Portugal. Six hundred clerks were interviewed regarding their individual characteristics (age, gender, education, experience in the labour market, experience in the company). Their respective supervisors were asked to assess their competences using a list of thirty skills. Complementary models are used in this research, relating to earnings and the distribution of profit shares to employees. Analyses take the specific structure of the multilevel data into account. These different dimensions show that traditional human capital variables are important determinants for earnings, whereas competences explain the profit shares distributed to employees.Earnings ; Human capital ; Competences ; Profit sharing ; Banking sector ; Portugal

INTEGRAL and Nuclear Astrophysics

We briefly review the fundamentals of nuclear gamma-ray line astronomy (radioactive astronomy), focusing on its role to decipher the intimate physics of supernovae, either immediatly (via $^{56}Co)$ or after a time delay (via $^{44}Ti$). All kinds of supernovae can be in principle tested through their radioactivities and their associated gamma-ray lines. Dedicated to the spectroscopy and imaging of celestial sources in the 15 keV to 10 MeV band, the ESA scientific observatory INTEGRAL will open a golden age of nuclear astrophysics in EuropeComment: Invited review, "Cosmic Evolution", meeting in honor of the 60th birthday of Jean Audouze and Jim Truran, to be published by World Scientific, 6 pages, 1 figur

Nuclear Gamma ray Astronomy in the perspective of the INTEGRAL satellite

We present a broad overview of the principal processes and astrophysical sites of gamma-ray line production and review the main pre-INTEGRAL satellite observations to set the stage to the next European era of gamma-ray line astronomy.Comment: 5 pages, 0 figures, in "International Nuclear Physics Conference, Paris, August 1998, to be published Elsevier Ed

The role of recent experience and weight on hen's agonistic behaviour during dyadic conflict resolution.

Recent victory or defeat experiences and 2-hour familiarity with the meeting place were combined with size differences in order to better understand their effects on the behaviour leading to the establishment of dyadic dominance relationships between hens not previously acquainted with each other. Three kinds of encounters were videotaped: (i) a previous winner unfamiliar with the meeting place met a previous loser familiar for 2 hours with the meeting place (n = 12 dyads); (ii) as in (i) but both were unfamiliar with the meeting place (n=12); (iii) as in (i) but the previous winner was familiar with the meeting place while the previous loser was unfamiliar (n=13). The weight asymmetry was combined with these three types of encounters by selecting hens of various weight differences: in 29 dyads the recent loser was heavier than the recent winner and in 8 dyads it was the reverse. Recent experience had a major influence upon both agonistic behaviour and dominance outcome. Hens that were familiar with the meeting site initiated attacks more frequently than their unfamiliar opponent but did not win significantly more often. Recent experience and site familiarity could be used to identify 80% of future initiators. Once the first aggressive behaviour had been initiated, it led to victory of its initiator in 92% of cases. Weight was not found to influence agonistic behaviour nor dominance outcome. However, hens with superior comb and wattles areas won significantly more initial meetings than opponents with smaller ones. In the final encounters, victory also went more frequently to the bird showing larger comb and wattles, which happened also to be the previous dominant in a majority of cases. The use of higher-order partial correlations as an ex post facto control for comb and wattles indicates that they were not influential upon agonistic behaviour nor on dominance outcome, but were simply co-selected with the selection of victorious and defeated birds in the first phase of the experiment designed to let hens acquire recent victory/defeat experience

The role of hen's weight and recent experience on dyadic conflict outcome

This study simultaneously varied experiences of recent victory or defeat, 2-hour familiarity with the meeting place, and hen weight in order to understand their combined effects on the establishment of dyadic dominance relationships between hens not previously acquainted with each other. Three kinds of encounters were arranged: (i) a previous winner unfamiliar with the meeting place met a previous loser familiar with the meeting place (n =28 dyads); (ii) a previous winner met a previous loser, both unfamiliar with the meeting place (n=27); (iii) a previous winner familiar with the meeting place encountered a previous loser unfamiliar with the meeting place (n=28). The weight asymmetry was combined with these three types of encounters by selecting hens showing various weight differences, in favour of the recent loser in 54 dyads and of the recent winner in 29 dyads. Results indicate that recent victory or defeat experience significantly affected the outcome. Even an important weight asymmetry, or familiarity with the meeting place were not sufficient for a hen recently defeated to overcome an opponent that was previously victorious. A 2-hour period of familiarization with the meeting place did not provide any significant advantage over unfamiliarity. Although a significant relationship was found to exist between comb and wattles areas and the initial and final statuses, examination of partial correlations indicates that the influence was from initial status to final status, rather than from comb and wattles to final status. These results suggest that more importance should be attributed to recent social experience in comparison to intrinsic factors in determining dyadic dominance in the hen