237 research outputs found
Integration theories and European education policy: bringing the role of ideas back in
Education policy, traditionally a fortress of state-building processes, is now being challenged by the emergence of a new dimension at the European level. The Lisbon Strategy of 2000 has not only redefined education as a tool for improving Europe’s competitiveness within the knowledge economy, but it has also significantly expanded the role of the European Commission as a legitimate actor intervening in education. Although the increasing involvement of the EU in education has been empirically covered by the existing literature, less attention has been devoted to elucidating these changes from a theoretical point of view. This article contends that these transformations raise a theoretical puzzle in terms of the understanding of the two mainstream theories of European integration. This argument is developed in three steps. First, the article examines the historical developments of EU competences in education. It then critically engages with the main theoretical explanations of European integration theories in relation to these changes, namely supranationalism and liberal intergovernmentalism, asserting that these approaches do not fully account for a comprehensive explanation of the drivers behind these transformations. By contrast, the article suggests that broadening the analytical lens to include a more ideas-centred approach provides a more in-depth understanding of European education policy
Economic Methodology for Pasture Grass and Legume Seed Production
The importance and complexity of the industrial process of seed production is known. Thus, conditions should be established for achieving and efficiently controlling the activity in order to know production costs, selling prices and to guarantee economic efficiency. The objective of this paper was to evaluate from an economic point of view, seed production of species of tropical grasses and legumes based on a preliminary methodology facilitating the control of the whole activity
Near to short wave infrared light generation through AlGaAs-on-insulator nanoantennas
AlGaAs-on-insulator (AlGaAs-OI) has recently emerged as a promising platform for nonlinear optics at the nanoscale. Among the most remarkable outcomes, second-harmonic generation (SHG) in the visible/near infrared spectral region has been demonstrated in AlGaAs-OI nanoantennas (NAs). In order to extend the nonlinear frequency generation towards the short wave infrared window, in this work we propose and demonstrate via numerical simulations difference frequency generation (DFG) in AlGaAs-OI NAs. The NA geometry is finely adjusted in order to obtain simultaneous optical resonances at the pump, signal and idler wavelengths, which results in an efficient DFG with conversion efficiencies up to 0.01%. Our investigation includes the study of the robustness against random variations of the NA geometry that may occur at fabrication stage. Overall, these outcomes identify what we believe to be a new potential and yet unexplored application of AlGaAs-OI NAs as compact devices for the generation and control of the radiation pattern in the near to short infrared spectral region
Integrated Generation of High-dimensional Entangled Photon States and Their Coherent Control
We demonstrate the generation of high-dimensional entangled photon pairs with a Hilbert-space dimensionality larger than 100 from an on-chip nonlinear microcavity, and introduce a coherent control scheme using standard telecommunications components
The effects of sex-ratio and density on locomotor activity in the house fly, Musca domestica
Although locomotor activity is involved in almost all behavioral traits, there is a lack of knowledge on what factors affect it. This study examined the effects of sex—ratio and density on the circadian rhythm of locomotor activity of adult Musca domestica L. (Diptera: Muscidae) using an infra—red light system. Sex—ratio significantly affected locomotor activity, increasing with the percentage of males in the vials. In accordance with other studies, males were more active than females, but the circadian rhythm of the two sexes was not constant over time and changed during the light period. There was also an effect of density on locomotor activity, where males at intermediate densities showed higher activity. Further, the predictability of the locomotor activity, estimated as the degree of autocorrelation of the activity data, increased with the number of males present in the vials both with and without the presence of females. Overall, this study demonstrates that locomotor activity in M. domestica is affected by sex—ratio and density. Furthermore, the predictability of locomotor activity is affected by both sex—ratio, density, and circadian rhythm. These results add to our understanding of the behavioral interactions between houseflies and highlight the importance of these factors when designing behavioral experiments using M. domestica
Epidemiology of Toxoplasma and CMV serology and of GBS colonization in pregnancy and neonatal outcome in a Sicilian population
Background: Aim of our study is to analyze the immunological status in pregnancy for two main TORCH agents, Toxoplasma and Cytomegalovirus (CMV), and the results of group B streptococcus (GBS) screening, assessing the risk for congenital infection in a population from Palermo, Italy.
Methods: We retrospectively analyzed the medical records of all inborn live newborns who were born in our division during 2012, gathering information about the mother, the pregnancy and neonatal hospitalization at birth. Whenever data were available, we categorized the serologic status of the mothers for Toxoplasma and CMV. We also considered the results of rectal and vaginal swabs for GBS. We compared the results in Italian and immigrant mothers. The neonatal outcome was evaluated in all cases at risk.
Results: Prevalence of anti-Toxo IgG antibodies was 17.97%, and was significantly higher in immigrant women (30% vs 16.4% in Italian women; p = 0.0008). Prevalence of anti-CMV IgG antibodies was 65.87%. Again, it was significantly higher in immigrant women (91.4% vs 62.5%, p = 3.31e-08). We compared those data with a previous study performed in our hospital in 2005-2006, and found that the prevalence of anti-Toxoplasma and anti-CMV antibodies in our population has remained stable, both in the immigrant and in the local population. Seroconversion rates and neonatal infections were rare: no seroconversions were observed for Toxoplasma, 4 seroconversions for CMV. One neonatal Toxoplasma infection and two neonatal CMV infections were documented. In some cases with dubious patterns or probable persistence of IgM, we performed additional tests and follow-up. Vaginal and rectal swabs were positive for GBS in 7.98% of cases, with no significant difference between the Italian and the immigrant population. No GBS neonatal sepsis was documented.
Conclusions: The prevalence of Toxoplasma IgG antibodies in pregnant women was low in our population, if compared with European countries and with other parts of Italy, and is significantly higher in immigrant women. The prevalence of CMV IgG antibodies was intermediate if compared to other countries, and it was higher in immigrant women. GBS positivity was low, and comparable in Italian and immigrant mothers. Neonatal infection was rare for all these agents
Effects of post-mortem storage conditions of bovine epididymides on sperm characteristics:investigating a tool for preservation of sperm from endangered species
The aim of this study was to establish and validate a reliable and efficient protocol for the recovery and cryopreservation of epididymal spermatozoa used for in vitro fertilization, using bulls of two different age classes. Testicles from 26 (37–51 weeks old, group 1) and 19 (52–115 weeks old, group 2) Danish Holstein bulls were collected after slaughter and stored at 5°C. After 0, 24 or 48 h, epididymides were isolated and spermatozoa collected. Assessments included spermatozoal motility, viability and morphology before and after cryopreservation and in vitro embryo production. Results showed that live spermatozoa can be collected from epididymides of bulls after their death. Storage of the testicles at 5°C for 24 h followed by cryopreservation of recovered epididymal spermatozoa resulted in 21% (group 1) and 31% (group 2) blastocysts produced in vitro. These results illustrate that epididymal spermatozoa recovered from testicles kept in specific conditions can be used to preserve genetic material from endangered and threatened species or populations in nature as well as in domestic and zoo animals
Enhancing second harmonic generation by Q-boosting lossless cavities beyond the time bandwidth limit
Nanostructures proved to be versatile platforms to control the electromagnetic field at subwavelength scale. Indeed, high-quality-factors nanocavities have been used to boost and control nonlinear frequency generation by increasing the light-matter interaction. However, nonlinear processes are triggered by high-intensities, which are provided by ultrashort laser pulses with large bandwidth, that cannot be fully exploited in such devices. Time-varying optical systems allow one to overcome the time-bandwidth limit by modulating the cavity external coupling. Here we present a general treatment, based on coupled mode theory, to describe second harmonic generation in a doubly resonant cavity for which the quality-factor at the fundamental frequency is modulated in time. We identify the initial quality factor maximizing second harmonic efficiency when performing Q-boosting and we predict a theoretical conversion efficiency close to unity. Our results have direct impact on the design of next generation time-dependent metasurfaces to boost nonlinear frequency conversion of ultrashort laser pulses
Surface Periodic Poling in Lithium Niobate and Lithium Tantalate
Periodic Poling of Lithium Niobate crystals (PPLN) by means of electric field has revealed the best technique for finely tailoring PPLN structures and parameters, which play a central role in many current researches in the field of nonlinear integrated optics.
Besides the most studied technique of bulk poling, recently a novel technique where domain inversion occurs just in a surface layer using photoresist or silica masks has been devised and studied. This surface periodic poling (SPP) approach is best suited when light is confined in a thin surface guiding layer or stripe, as in the case of optical waveguide devices.
Also, we found that SPP respect to bulk poling offers two orders of magnitude reduction on the scale of periodicity, so that even nanostructures can be obtained provided an high resolution holographic mask writing technique is adopted. We were able to demonstrate 200 nm domain size, and also good compatibility with alpha-phase proton exchange channel waveguide fabrication.
Our first experiments on Lithium Tantalate have also shown that the SPP technology appears to be applicable to this crystal (SPPLT), whose properties can allow to overcome limitations such as optical damage or UV absorption still present in PPLN devices.
Finally, the issue of SPP compatibility with proton exchange waveguide fabrication will be addresse
Effect of landscape elements on the symmetry and variance of the spatial distribution of individual birds within foraging flocks of geese
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