Complements or substitutes? Immigrant and native task specialization in Spain

Learning about the impact that immigration has on the labor market of the receiving nation is a topic of major concern, particularly in Spain, where immigration has more than doubled from 4 percent to roughly 10 percent of the population within a decade. Yet, very little is known about the impact that large immigrant inflows have had on the labor market outcomes of Spanish natives. Furthermore, most studies assume that natives and immigrants are perfect substitutes within skill groups –a questionable assumption given recent findings in the literature. In this paper, we first document that foreign-born workers are not perfect substitutes of similarly skilled native Spanish workers, which may help explain why immigration has not significantly lowered natives’ wages. Instead, immigration has affected the occupational distribution of natives. Specifically, owing to the comparative advantage of foreign-born workers in manual as opposed to interactive tasks, natives relocated to occupations with a lower content of manual tasks –such as technical and alike professional occupations, clerical support jobs, and sales and service occupations. Yet, possibly owing to the significant and simultaneous reduction in the manual to interactive task supply resulting from the increase in the share of native female workers, the increase in the relative supply of manual to interactive tasks from foreign-born workers does not appear to have significantly changed the overall manual to interactive task supply in the Spanish economy

Impurity crystal in a Bose-Einstein condensate

We investigate the behavior of impurity fields immersed in a larger condensate field in 1, 2, and 3 dimensions. We discuss the localization of a single impurity field within a condensate and note the effects of surface energy. We derive the functional form of the attractive interaction between two impurities due to mediation from the condensate. Generalizing the analysis to $N$ impurity fields, we show that within various parameter regimes a crystal of impurity fields can form spontaneously in the condensate. Finally, the system of condensate and crystallized impurity structure is shown to have nonclassical rotational inertia, which is characteristic of superfluidity, i.e. the system can be seen to exhibit supersolid behavior.Comment: 5 pages, 3 color figures; Accepted to Phys. Rev. Let

The Possibility of Extending the Detection Function of an Analytical System to Lower Concentrations

It is shown that the only way to increase the detection capacity of an analytical system is based on the use of the multitude values of the single analytical signal. This can be achieved in two modalities: 1) fixed multitude values (as mean or as sum), and 2) sequential multitude values (as signal sum and as frequencies sum). By using these procedures, the analytical detection can be applied under the classical detection limit at as low concentrations as desired, provided that the multitude of the individual values of the signal be sufficiently high

Inhaled aerosolised recombinant human activated protein C ameliorates endotoxin-induced lung injury in anaesthetised sheep

Introduction We recently demonstrated that intravenously infused recombinant human activated protein C (APC) attenuates ovine lipopolysaccharide (LPS)-induced lung injury. In this study, our aim was to find out whether treatment with inhaled aerosolised APC (inhAPC) prevents formation of increased lung densities and oedema and derangement of oxygenation during exposure to LPS. Methods: Sheep were anaesthetised during placement of intravascular introducers. After one to four days of recovery from instrumentation, the animals were re-anaesthetised, endotracheally intubated and mechanically ventilated throughout a six-hour experiment where the sheep underwent quantitative lung computed tomography. Sheep were randomly assigned to one of three groups: a sham-operated group (n = 8) receiving inhaled aerosolised saline from two hours after the start of the experiment; a LPS group (n = 8) receiving an intravenous infusion of LPS 20 ng/kg per hour and, after two hours, inhaled aerosolised saline over the next four hours; a LPS+inhAPC group (n = 8) receiving an intravenous infusion of LPS 20 ng/kg per hour and, after two hours, aerosolised APC 48 µg/kg per hour inhaled throughout the experiment. Data were analysed with analysis of variance; P less than 0.05 was regarded as significant. Results: An infusion of LPS was associated with a reduction of well-aerated lung volume and a rapid fall in arterial oxygenation that were both significantly antagonised by inhaled APC. Pulmonary vascular pressures and extravascular lung water index increased significantly during exposure to LPS, but inhaled APC had no effect on these changes. Conclusions: Inhalation of aerosolised APC attenuates LPSinduced lung injury in sheep by preventing a decline in the volume of aerated lung tissue and improving oxygenation

Organizational Factors Contributing to Workplace Stress Among Office Professionals in Selected Hospitals in Laguna: Basis for Stress Management Program

This study determined the organizational factors contributing to workplace stress among office professionals in selected hospitals in Laguna that served as a basis for a stress management program. This quantitative research employed a descriptive correlational design using descriptive statistics in analyzing the data. Data were collected among 80 office professionals from four selected hospitals in Laguna, Philippines. Convenience sampling was utilized in choosing the respondents of the study. The study revealed that the respondents experienced or observed the following organizational factors: high in terms of leadership support, good for working conditions, fair for peer relationship, moderate for role ambiguity, while the workload is moderately heavy. It was also found out that the respondent’s physical and psychological stress is low. Moreover, correlation analysis revealed that role ambiguity, working condition, and leadership support is not significantly related to physical, psychological test, and the overall workplace stress and that there was no significant difference in the employees’ demographic profile considering the age, gender, highest educational attainment, year of service and civil status. Regression analysis also revealed that workload and peer relationship significantly predict workplace stress, with a variance accounted for 24.1%. Workload contributed a total of 19.3% of the variance in workplace stress and 4.8% for peer relationships and working conditions. This means the heavier the workload, the higher the workplace stress and the better peer relationship and working conditions, the higher the workplace stress. Based on the results, it is recommended that the proposed stress management program be utilized by the selected hospital respondents.Keywords: organizational factors, workplace stress, physical and psychological stress, peer relationship, working condition

Dynamics of a Vortex in a Trapped Bose-Einstein Condensate

We consider a large condensate in a rotating anisotropic harmonic trap. Using the method of matched asymptotic expansions, we derive the velocity of an element of vortex line as a function of the local gradient of the trap potential, the line curvature and the angular velocity of the trap rotation. This velocity yields small-amplitude normal modes of the vortex for 2D and 3D condensates. For an axisymmetric trap, the motion of the vortex line is a superposition of plane-polarized standing-wave modes. In a 2D condensate, the planar normal modes are degenerate, and their superposition can result in helical traveling waves, which differs from a 3D condensate. Including the effects of trap rotation allows us to find the angular velocity that makes the vortex locally stable. For a cigar-shape condensate, the vortex curvature makes a significant contribution to the frequency of the lowest unstable normal mode; furthermore, additional modes with negative frequencies appear. As a result, it is considerably more difficult to stabilize a central vortex in a cigar-shape condensate than in a disc-shape one. Normal modes with imaginary frequencies can occur for a nonaxisymmetric condensate (in both 2D and 3D). In connection with recent JILA experiments, we consider the motion of a straight vortex line in a slightly nonspherical condensate. The vortex line changes its orientation in space at the rate proportional to the degree of trap anisotropy and can exhibit periodic recurrences.Comment: 19 pages, 6 eps figures, REVTE