Field of study and partner choice

© 2021There is strong assortative mating by field of study. To examine to which extent this is due to self selection or to a causal effect of access to specific ”marriage markets”, we use data from participants in admission lotteries of four oversubscribed studies in the Netherlands. For each of the four studies, we find that the winning compliers of an admission lottery are significantly more likely than the losing compliers to have a partner from the lottery study, whereas losing compliers are only marginally more likely to have a partner from the lottery study than would occur under random matching. These results indicate that assortative mating by field of study is largely due to marriage market access and that self selection plays a minor role. JEL-codes: I26, J12, J13

Feasibility of an In-Situ Microbial Decontamination of an Ice-Melting Probe

Autonomous robotic systems for penetrating thick ice shells with simultaneous collecting of scientific data are very promising devices in both terrestrial (glacier, climate research) and extra-terrestrial applications. Technical challenges in development of such systems are numerous and include 3D-navigation, an appropriate energy source, motion control, etc. Not less important is the problem of forward contamination of the pristine glacial environments with microorganisms and biomolecules from the surface of the probe. This study was devoted to establishing a laboratory model for microbial contamination of a newlyconstructed ice-melting probe called IceMole and to analyse the viability and amount of the contaminating microorganisms as a function of distance. The used bacterial strains were Bacillus subtilis (ATCC 6051) and Escherichia coli (ATCC 11775). The main objective was development of an efficient and reliable in-situ decontamination method of the melting probe. Therefore, several chemical substances were tested in respect of their efficacy to eliminate bacteria on the surface of the melting probe at low temperature (0 - 5 °C) and at continuous dilution by melted water. Our study has shown that at least 99.9% decontamination of the IceMole can be successfully achieved by the injection of 30% (v/v) hydrogen peroxide and 3% (v/v) sodium hypochlorite into the drilling site. We were able to reproduce this result in both time-dependent and depth-dependent experiments. The sufficient amount of 30% (v/v) H2O2 or 3% (v/v) NaClO has been found to be approximately 18 L per cm² of the probe’s surface

Fresnel laws at curved dielectric interfaces of microresonators

We discuss curvature corrections to Fresnel's laws for the reflection and transmission of light at a non-planar refractive-index boundary. The reflection coefficients are obtained from the resonances of a dielectric disk within a sequential-reflection model. The Goos-H\"anchen effect for curved light fronts at a planar interface can be adapted to provide a qualitative and quantitative extension of the ray model which explains the observed deviations from Fresnel's laws.Comment: submitted to Phys. Rev.

Kaspar Schott’s “encyclopedia of all mathematical sciences”

In 1661, Kaspar Schott published his comprehensive textbook “Cursus mathematicus” in Würzburg for the first time, his “Encyclopedia of all mathematical sciences”. It was so successful that it was published again in 1674 and 1677. In its 28 books, Schott gave an introduction for beginners in 22 mathematical disciplines by means of 533 figures and numerous tables. He wanted to avoid the shortness and the unintelligibility of his predecessors Alsted and Hérigone. He cited or recommended far more than hundred authors, among them Protestants like Michael Stifel and Johannes Kepler, but also Catholics like Nicolaus Copernicus. The paper gives a survey of this work and explains especially interesting aspects: The dedication to the German emperor Leopold I., Athanasius Kircher’s letter of recommendation as well as Schott’s classification of sciences, explanations regarding geometry, astronomy, and algebra

Geometric Spin Hall Effect of Light at Polarizing Interfaces

The geometric Spin Hall Effect of Light (geometric SHEL) amounts to a polarization-dependent positional shift when a light beam is observed from a reference frame tilted with respect to its direction of propagation. Motivated by this intriguing phenomenon, the energy density of the light beam is decomposed into its Cartesian components in the tilted reference frame. This illustrates the occurrence of the characteristic shift and the significance of the effective response function of the detector. We introduce the concept of a tilted polarizing interface and provide a scheme for its experimental implementation. A light beam passing through such an interface undergoes a shift resembling the original geometric SHEL in a tilted reference frame. This displacement is generated at the polarizer and its occurrence does not depend on the properties of the detection system. We give explicit results for this novel type of geometric SHEL and show that at grazing incidence this effect amounts to a displacement of multiple wavelengths, a shift larger than the one introduced by Goos-H\"anchen and Imbert-Fedorov effects.Comment: 6 pages, 4 figure

Technoscientia est Potentia?: Contemplative, interventionist, constructionist and creationist idea(l)s in (techno)science

Within the realm of nano-, bio-, info- and cogno- (or NBIC) technosciences, the ‘power to change the world’ is often invoked. One could dismiss such formulations as ‘purely rhetorical’, interpret them as rhetorical and self-fulfilling or view them as an adequate depiction of one of the fundamental characteristics of technoscience. In the latter case, a very specific nexus between science and technology, or, the epistemic and the constructionist realm is envisioned. The following paper focuses on this nexus drawing on theoretical conceptions as well as empirical material. It presents an overview of different technoscientific ways to ‘change the world’—via contemplation and representation, intervention and control, engineering, construction and creation. It further argues that the hybrid character of technoscience makes it difficult (if not impossible) to separate knowledge production from real world interventions and challenges current science and technology policy approaches in fundamental ways

Interplay between n-3 and n-6 long-chain polyunsaturated fatty acids and the endocannabinoid system in brain protection and repair.

The brain is enriched in arachidonic acid (ARA) and docosahexaenoic acid (DHA), long-chain polyunsaturated fatty acids (LCPUFA) of the n-6 and n-3 series, respectively. Both are essential for optimal brain development and function. Dietary enrichment with DHA and other long-chain n-3 PUFA, such as eicosapentaenoic acid (EPA) have shown beneficial effects on learning and memory, neuroinflammatory processes and synaptic plasticity and neurogenesis. ARA, DHA and EPA are precursors to a diverse repertoire of bioactive lipid mediators, including endocannabinoids. The endocannabinoid system comprises cannabinoid receptors, their endogenous ligands, the endocannabinoids, and their biosynthetic and degradation enzymes. Anandamide (AEA) and 2-archidonoylglycerol (2-AG) are the most widely studied endocannabinoids, and are both derived from phospholipid-bound ARA. The endocannabinoid system also has well established roles in neuroinflammation, synaptic plasticity and neurogenesis, suggesting an overlap in the neuroprotective effects observed with these different classes of lipids. Indeed, growing evidence suggests a complex interplay between n-3 and n-6 LCPUFA and the endocannabinoid system. For example, long-term DHA and EPA supplementation reduces AEA and 2-AG levels, with reciprocal increases in levels of the analogous endocannabinoid-like DHA and EPA-derived molecules. This review summarises current evidence of this interplay and discusses the therapeutic potential for brain protection and repair

Educação no trabalho na atenção primária à saúde: interfaces entre a educação permanente em saúde e o agir comunicativo

O trabalho em saúde e a educação no trabalho constituem-se com uma dupla dimensão - ação instrumental e intersubjetividade. OBJETIVO: Analisar as concepções de educação que fundamentam as atividades educativas de trabalhadores da saúde na atenção primária. MÉTODO: Estudo de abordagem qualitativa realizado em duas unidades básicas de saúde do município de São Paulo, por meio de entrevista semiestruturada gravada com 36 informantes-chave, representativos de cada categoria profissional dos serviços, incluindo o segmento gerencial e o de trabalhadores da saúde. Os dados foram analisados com a técnica de análise de conteúdo temática com base no quadro teórico: processo de trabalho em saúde, teoria do agir comunicativo, educação continuada (EC), educação permanente em saúde (EPS) e integralidade, os quais permitiram a construção das categorias empíricas: educação instrumental/tradicional e educação comunicativa/emancipatória. Resultados: Os resultados mostram o predomínio da concepção de educação no trabalho como construção coletiva do saber a partir da realidade de trabalho, pertinentes à EPS que se pretende instituir para a mudança das práticas e do modelo assistencial biomédico. Contudo, alguns depoentes expressam uma concepção de educação instrumental com ênfase em ações técnicas e de atualização do saber, que se aproxima da EC. CONCLUSÃO: Os resultados evidenciam a convivência das duas concepções de educação de trabalhadores - instrumental e comunicativa com o predomínio da segunda, que mostra a capilaridade da política de EPS entre os trabalhadores de saúde das UBS e a necessidade de aprofundar o debate para consolidar a prática educativa no cotidiano de trabalho.Health work and work education are a double dimension - instrumental action and intersubjectivity. OBJECTIVE: To analyze the conceptions of education that support educational activities of health care workers in Primary Health Care. METHOD: This qualitative study was conducted in two primary health care units (PHCU) in São Paulo, through semi-structured interviews with 36 key informants representing each professional category, including managers and health care workers. Data were analyzed based on thematic content analysis and on the theoretical framework: the healthcare work process, theory of communicative action, continuing education (CE), permanent education in health (PEH) and integrality (comprehensive approach), which allowed the construction of the empirical categories: instrumental/traditional education and communicative/emancipatory education. RESULTS: The results show the prevailing notion of work education as a collective construction of knowledge from the reality of work, relevant to the PEH that is intended to be introduced in order to change the practices and the biomedical health care model. However, some interviewed subjects expressed an instrumental conception of education that emphasizes technical actions and knowledge updating, which is closer to CE. Conclusion: Results show the coexistence of the two conceptions of workers' education: instrumental and communicative, with the predominance of the second one, which shows the reach of the PEH policy among the health workers of PHCU and the need for deepening the discussion to consolidate educational practice in daily work

Design concepts for the Cherenkov Telescope Array CTA: an advanced facility for ground-based high-energy gamma-ray astronomy

Ground-based gamma-ray astronomy has had a major breakthrough with the impressive results obtained using systems of imaging atmospheric Cherenkov telescopes. Ground-based gamma-ray astronomy has a huge potential in astrophysics, particle physics and cosmology. CTA is an international initiative to build the next generation instrument, with a factor of 5-10 improvement in sensitivity in the 100 GeV-10 TeV range and the extension to energies well below 100 GeV and above 100 TeV. CTA will consist of two arrays (one in the north, one in the south) for full sky coverage and will be operated as open observatory. The design of CTA is based on currently available technology. This document reports on the status and presents the major design concepts of CTA