1,190 research outputs found

    Job mobility and wage growth between regions

    Full text link
    Individual wage growth is higher in more densely populated regions. Using data on detailed labour market biographies from Germany, this paper shows that job mobility contributes to this urban premium in wage growth. In urban regions, wage growth is higher both within jobs and between jobs. The higher between-job wage growth is driven by a combination of higher frequency of job changes and a higher payoff of moving between jobs. This finding is consistent with better coordination in denser labour markets. Further evidence shows that the gain from higher urban wage growth is not lost upon moving across regions, suggesting that a better job match results in higher human capital accumulation

    Urban wage premia and heterogeneous sorting

    Full text link
    Wages are higher in urban regions. These urban wage premia may be driven by sorting of more productive workers into urban regions, by a static productivity advantage, and by higher wage growth. This paper documents a size-earnings elasticity of five per cent in Germany. Sorting of more productive workers into larger regions explains 40 per cent of this elasticity. The remainder is driven in equal parts by a static productivity effect and a dynamic learning effect. The urban wage premium is strongly increasing in educational attainment. This is largely driven by different degrees of sorting between education groups. Similarly, there are large urban wage premium differences between occupation groups, which are entirely driven by differences in sorting

    Occupational change and wage inequality in Germany

    Full text link
    Wage inequality between education groups in Germany has increased sharply in recent decades. This paper studies how compositional changes to the occupational structure and the geographic distribution of different types of jobs have affected this type of inequality. Employment has shifted away from traditionally mid-paying production occupations towards higher-paying cognitive/interactive occupations, and – to a lesser extent – towards low-paying manual services. However, only workers with university degrees have benefited from the expansion of higher-paid work. This increase in polarization played out relatively evenly across space. While such occupational shifts can contribute to between-group wage inequality, in the German case, the increase in occupational polarization was not large enough to materially contribute to wage inequality between education groups

    Functional Diversity of Photosynthetic Light Use of 16 Vascular Epiphyte Species Under Fluctuating Irradiance in the Canopy of a Giant Virola michelii (Myristicaceae) Tree in the Tropical Lowland Forest of French Guyana

    Get PDF
    Here we present the first study, in which a large number of different vascular epiphyte species were measured for their photosynthetic performance in the natural environment of their phorophyte in the lowland rainforest of French Guyana. More than 70 epiphyte species covered the host tree in a dense cover. Of these, the photosynthesis of 16 abundant species was analyzed intensely over several months. Moreover, the light environment was characterized with newly developed light sensors that recorded continuously and with high temporal resolution light intensity next to the epiphytes. Light intensity was highly fluctuating and showed great site specific spatio-temporal variations of photosynthetic photon flux. Using a novel computer routine we quantified the integrated light intensity the epiphytes were exposed to in a 3 h window and we related this light intensity to measurements of the actual photosynthetic status. It could be shown that the photosynthetic apparatus of the epiphytes was well adapted to the quickly changing light conditions. Some of the epiphytes were chronically photoinhibited at predawn and significant acute photoinhibition, expressed by a reduction of potential quantum efficiency (Fv/Fm)30′, was observed during the day. By correlating (Fv/Fm)30′ to the integrated and weighted light intensity perceived during the previous 3 h, it became clear that acute photoinhibition was related to light environment prior to the measurements. Additionally photosynthetic performance was not determined by rain events, with the exception of an Aechmea species. This holds true for all the other 15 species of this study and we thus conclude that actual photosynthesis of these tropical epiphytes was determined by the specific and fluctuating light conditions of their microhabitat and cannot be simply attributed to light-adapted ancestors

    Laser interference lithography for nanostructured surfaces

    Get PDF

    Integrated Lithographic Molding for Microneedle-Based Devices

    Get PDF
    This paper presents a new fabrication method consisting of lithographically defining multiple layers of high aspect-ratio photoresist onto preprocessed silicon substrates and release of the polymer by the lost mold or sacrificial layer technique, coined by us as lithographic molding. The process methodology was demonstrated fabricating out-of-plane polymeric hollow microneedles. First, the fabrication of needle tips was demonstrated for polymeric microneedles with an outer diameter of 250 mum, through-hole capillaries of 75-mum diameter and a needle shaft length of 430 mum by lithographic processing of SU-8 onto simple v-grooves. Second, the technique was extended to gain more freedom in tip shape design, needle shaft length and use of filling materials. A novel combination of silicon dry and wet etching is introduced that allows highly accurate and repetitive lithographic molding of a complex shape. Both techniques consent to the lithographic integration of microfluidic back plates forming a patch-type device. These microneedle-integrated patches offer a feasible solution for medical applications that demand an easy to use point-of-care sample collector, for example, in blood diagnostics for lithium therapy. Although microchip capillary electrophoresis glass devices were addressed earlier, here, we show for the first time the complete diagnostic method based on microneedles made from SU-8
    corecore