The Migration of Skilled Women: A Case Study in the United

Abstract: This article concerns the case of Spanish women with higher education and their migration to the United Kingdom between 2009 and 2012. Based on an analysis of available statistical data and qualitative research (participant observation and 12 in-depth interviews), we explore the work and living conditions of migrant women. The results indicate: 1) that the number of migrants during the crisis is lower than previously thought and that, according to the available data, it cannot be classed as skilled migration; 2) similarly, that the socio-demographic profile is heterogeneous and, 3) that there are diverse economic conditions upon entry, often resulting in situations of vulnerability and social exclusion

Ionization fraction and the enhanced sulfur chemistry in Barnard 1

Barnard B1b has revealed as one of the most interesting globules from the chemical and dynamical point of view. It presents a rich molecular chemistry characterized by large abundances of deuterated and complex molecules. Furthermore, it hosts an extremely young Class 0 object and one candidate to First Hydrostatic Core (FHSC). Our aim was to determine the cosmic ray ionization rate and the depletion factors in this extremely young star forming region. We carried out a spectral survey towards Barnard 1b as part of the IRAM Large program ASAI using the IRAM 30-m telescope at Pico Veleta (Spain). This provided a very complete inventory of neutral and ionic C-, N- and S- bearing species with, up to our knowledge, the first secure detections of the deuterated ions DCS+ and DOCO+. We used a state-of-the-art pseudo-time-dependent gas-phase chemical model to determine the value of the cosmic ray ionization rate and the depletion factors. The observational data were well fitted with $\zeta_{H_2}$ between 3E-17 s$^{-1}$ and 1E-16 s$^{-1}$. Elemental depletions were estimated to be ~10 for C and O, ~1 for N and ~25 for S. Barnard B1b presents similar depletions of C and O than those measured in pre-stellar cores. The depletion of sulfur is higher than that of C and O but not as extreme as in cold cores. In fact, it is similar to the values found in some bipolar outflows, hot cores and photon-dominated regions. Several scenarios are discussed to account for these peculiar abundances. We propose that it is the consequence of the initial conditions (important outflows and enhanced UV fields in the surroundings) and a rapid collapse (~0.1 Myr) that permits to maintain most S- and N-bearing species in gas phase to great optical depths. The interaction of the compact outflow associated with B1b-S with the surrounding material could enhance the abundances of S-bearing molecules, as well.Comment: Paper accepted in Astronomy and Astrophysics; 28 pags, 21 figure

Dislocation Emission around Nanoindentations on a (001) fcc Metal Surface Studied by STM and Atomistic Simulations

We present a combined study by Scanning Tunneling Microscopy and atomistic simulations of the emission of dissociated dislocation loops by nanoindentation on a (001) fcc surface. The latter consist of two stacking-fault ribbons bounded by Shockley partials and a stair-rod dislocation. These dissociated loops, which intersect the surface, are shown to originate from loops of interstitial character emitted along the directions and are usually located at hundreds of angstroms away from the indentation point. Simulations reproduce the nucleation and glide of these dislocation loops.Comment: 10 pages, 4 figure

Spectral line survey of the ultracompact HII region Mon R2

Ultracompact (UC) HII regions constitute one of the earliest phases in the formation of a massive star and are characterized by extreme physical conditions (Go>10^5 Habing field and n>10^6 cm^-3). The UC HII Mon R2 is the closest one and therefore an excellent target to study the chemistry in these complex regions. We carried out a 3mm and 1mm spectral survey using the IRAM 30-m telescope towards three positions that represent different physical environments in Mon R2: (i) the ionization front (IF) at (0",0"); two peaks in the molecular cloud (ii) MP1 at the offset (+15",-15") and (iii) MP2 at the farther offset (0",40"). In addition, we carried out extensive modeling to explain the chemical differences between the three observed regions. We detected more than thirty different species. We detected SO+ and C4H suggesting that UV radiation plays an important role in the molecular chemistry of this region. We detected the typical PDR molecules CN, HCN, HCO, C2H, and c-C3H2. While the IF and the MP1 have a chemistry similar to that found in high UV field and dense PDRs like the Orion Bar, the MP2 is more similar to lower UV/density PDRs like the Horsehead nebula. We also detected complex molecules that are not usually found in PDRs (CH3CN, H2CO, HC3N, CH3OH and CH3C2H). Sulfur compounds CS, HCS+, C2S, H2CS, SO and SO2 and the deuterated species DCN and C2D were also identified. [DCN]/[HCN]=0.03 and [C2D]/[C2H]=0.05, are among the highest in warm regions. Our results show that the high UV/dense PDRs present a different chemistry from that of the low UV case. Abundance ratios like [CO+]/[HCO+] or [HCO]/[HCO+] are good diagnostics to differentiate between them. In Mon R2 we have the two classes of PDRs, a high UV PDR towards the IF and the adjacent molecular bar and a low-UV PDR which extends towards the north-west following the border of the cloud.Comment: 31 page

Physical structure of the photodissociation regions in NGC 7023: Observations of gas and dust emission with <i>Herschel</i>

The determination of the physical conditions in molecular clouds is a key step towards our understanding of their formation and evolution of associated star formation. We investigate the density, temperature, and column density of both dust and gas in the photodissociation regions (PDRs) located at the interface between the atomic and cold molecular gas of the NGC 7023 reflection nebula. We study how young stars affect the gas and dust in their environment. Our approach combining both dust and gas delivers strong constraints on the physical conditions of the PDRs. We find dense and warm molecular gas of high column density in the PDRs

Main Features Of Arbitration In Peru

Sustained economic growth cannot be achieved if the State does not protect two fundamental pillars that allow private agents to create wealth: contracts and property right

Physical characterization of 2020 AV2, the first known asteroid orbiting inside Venus orbit

The first known asteroid with the orbit inside that of Venus is 2020~AV$_{2}$. This may be the largest member of a new population of small bodies with the aphelion smaller than 0.718~au, called Vatiras. The surface of 2020~AV$_{2}$ is being constantly modified by the high temperature, by the strong solar wind irradiation that characterizes the innermost region of the Solar system, and by high-energy micrometeorite impacts. The study of its physical properties represents an extreme test-case for the science of near-Earth asteroids. Here, we report spectroscopic observations of 2020~AV$_{2}$ in the 0.5-1.5~$\mu m$ wavelength interval. These were performed with the Nordic Optical Telescope and the William Herschel Telescope. Based on the obtained spectra, we classify 2020~AV$_{2}$ as a Sa-type asteroid. We estimate the diameter of this Vatira to be $1.50_{-0.65}^{+1.10}$ km by considering the average albedo of A-type and S-complex asteroids ($p_V=0.23_{-0.08}^{+0.11}$), and the absolute magnitude (H=$16.40\pm0.78$ mag). The wide spectral band around 1~$\mu m$ shows the signature of an olivine rich composition. The estimated band centre $BIC = 1.08 \pm 0.02~\mu m$ corresponds to a ferroan olivine mineralogy similar to that of brachinite meteorites.Comment: Accepted for publication in MNRAS. 10 pages, 5 figures

Sustainability-driven decision-making model: case study of fiber-reinforced concrete foundation piles

Currently, foundation piles for inhabited areas are often constructed using a continuous flight auger, which is a cost- and time-efficient technology that does not require stabilization of the borehole wall; the steel bar reinforcement is embedded after the concrete has been poured. However, this reinforcement operation can lead to severe construction and structural issues. Thus, several improvements to this technology have been proposed since its first application in the 20th century, such as the use of more fluid concretes. Nevertheless, steel and polymers are emerging as a potential replacement for steel bars in concrete reinforcement for several types of structures and building components, with identified and quantified benefits from a sustainability perspective. Accordingly, this paper proposes and validates a multicriteria decision-making approach designed with multidisciplinary experts within the construction field to assess the sustainability index of concrete pile foundations. The results of a case study enable us to conclude that polymeric fiber-reinforced concrete piles are the most sustainable due to their cost–structural efficiency ratio, high durability, and minimal risks during construction. Steel fiber-reinforced concrete alternatives were also found to be more sustainable than traditional reinforced concrete. Nonetheless, these results are unrepresentative of the current practice as direct costs were found to be the main driver in the decision-making processes, while other costs and both environmental and social indicators are disregarded. This justifies the urgency to provide sustainability-driven decision-making approaches capable of objectively quantifying the satisfaction degree of economic, environmental, and social indicators involved in the analysis

Mid-infrared PAH and H2 emission as a probe of physical conditions in extreme PDRs

Mid-infrared (IR) observations of polycyclic aromatic hydrocarbons (PAHs) and molecular hydrogen emission are a potentially powerful tool to derive physical properties of dense environments irradiated by intense UV fields. We present new, spatially resolved, \emph{Spitzer} mid-IR spectroscopy of the high UV-field and dense photodissocation region (PDR) around Monoceros R2, the closest ultracompact \hII region, revealing the spatial structure of ionized gas, PAHs and H$_2$ emissions. Using a PDR model and PAH emission feature fitting algorithm, we build a comprehensive picture of the physical conditions prevailing in the region. We show that the combination of the measurement of PAH ionization fraction and of the ratio between the H$_2$ 0-0 S(3) and S(2) line intensities, respectively at 9.7 and 12.3 $\mu$m, allows to derive the fundamental parameters driving the PDR: temperature, density and UV radiation field when they fall in the ranges $T = 250-1500$K, $n_H=10^4-10^6$cm$^{-3}$, $G_0=10^3-10^5$ respectively. These mid-IR spectral tracers thus provide a tool to probe the similar but unresolved UV-illuminated surface of protoplanetary disks or the nuclei of starburst galaxies.Comment: Accepted for publication in ApJ Letter

An Application of Item Response Theory to Basic Science Multiple-Choice Test Development and Validation

The study made use of instrumentation research design while item response theory was applied, to develop and validate Basic Science multiple-choice tests. 600 junior secondary school II students consisted of a sample that was randomly selected from 20 government co-education secondary schools in Udi education zone of Enugu State, Nigeria. The study was guided by six research questions. A 40-test item of Basic Science multiple choice test was constructed by the researchers and used to collect data. Three experts subjected the instrument to content and face validation to ensure its validity. Two of them were from the departments of Science education and educational foundations, respectively. A reliability index of 0.85, was realized. Analysis of the data that were generated, was carried out, using the maximum likelihood estimation technique of BILOG-MG computer programming. It revealed that 40-test items with the appropriate indices consisted of the final instrument developed and was used to assess the ability of students in Basic Science. The result of the study confirmed the reliability of the items of the Basic Science Multiple choice questions based on the three-parameter (3pl) model. The findings again revealed that the multiple-choice Basic Science test items were difficult and that there was differential item functioning in Basic Science among male and female learners. Recommendations that were in line with the findings were made, such as that: teachers and examination bodies should adopt and encourage IRT in the development of test instruments used in measuring the ability of students in Basic Science and other subjects