Immigration and Housing Booms: Evidence from Spain

We estimate empirically the effect of immigration on house prices and residential construction activity in Spain over the period 1998-2008. This decade is characterized by both a spectacular housing market boom and a stunning immigration wave. We exploit the variation in immigration across Spanish provinces and construct an instrument based on the historical location patterns of immigrants by country of origin. The evidence points to a sizeable causal effect of immigration on both prices and quantities in the housing market. Between 1998 and 2008, the average Spanish province received an immigrant inflow equal to 17% of the initial working-age population. We estimate that this inflow increased house prices by about 52% and is responsible for 37% of the total construction of new housing units during the period. These figures imply that immigration can account for roughly one third of the housing boom, both in terms of prices and new construction.Housing market, Immigration, House prices, Construction, Spain

Immigration, Family Responsibilities and the Labor Supply of Skilled Native Women

This paper investigates the effects of Spain's large recent immigration wave on the labor supply of highly skilled native women. We hypothesize that female immigration led to an increase in the supply of affordable household services, such as housekeeping and child or elderly care. As a result, i) native females with high earnings potential were able to increase their labor supply, and ii) the effects were larger on skilled women whose labor supply was heavily constrained by family responsibilities. Our evidence indicates that over the last decade immigration led to an important expansion in the size of the household services sector and to an increase in the labor supply of women in high-earning occupations (of about 2 hours per week). We also find that immigration allowed skilled native women to return to work sooner after childbirth, to stay in the workforce longer when having elderly dependents in the household, and to postpone retirement. Methodologically, we show that the availability of even limited Registry data makes it feasible to conduct the analysis using quarterly household survey data, as opposed to having to rely on the decennial Census.Immigration, Labor supply, Fertility, Retirement, Household services

Anaesthesia for trauma patients

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Development of encapsulated olive leaf extracts as innovative natural and functional food ingredients

The increasing consumer concern and demand in the last decades for foods with natural ingredients and enhanced nutritional and health-promoting properties has pushed the research in the fields of nutrition and food technology in order to find, characterize, formulate and incorporate bioactive compounds into common foods or nutraceuticals. Some of the most used food bioactives are plant phytochemicals like polyphenols present in most plants as secondary metabolites. Olive biophenols, present in most parts of the plant and found in high concentrations in the leaves, are widely recognized for their bioactive properties. Thus, olive leaves, traditionally considered as a by-product, are an abundant source of olive phenolic compounds that can be recovered and further exploited as functional ingredients in food and nutraceuticals. However, the intrinsic chemical characteristics of these and other phytochemicals compounds makes its direct use in foods very challenging. In this context, food microencapsulation has been progressively implemented to partially or totally tackle these technological and sensorial issues associated to their incorporation into foods. The large variety of bioactives (pure compounds, phenolic-rich extracts) and carriers, the specific objective of the encapsulation and the large complexity of food matrices are the reasons for the wide research and development approaches in this field. Due to the different nature of the encapsulation techniques, specific investigations on their related critical parameters and optimization of the encapsulation process and performance are needed. The investigations carried out in this work aimed to better understand the use of phenolic extracts from olive leaves by studying its chemical stability and developing encapsulated ingredients with encapsulation techniques of different nature with the potential to be used in real food matrices. Firstly, a phenolic extract from olive leaves rich in oleuropein, a well defined compound with significant health-promoting properties, was characterised in terms of thermal stability at varying pH conditions of the phenolic content, profile and radical scavenging properties, by implementing a kinetic model and also structural characterization using flurescence spectroscopy.The thermal degradation of the major component, oleuropein, followed first-order kinetics and was high at lowest pH values (pH = 2), while verbascoside appeared to be more labile at pH 6. Oleuropein hydrolysis products resulted in an increasing hydroxytyrosol concentration, that followed zero-order kinetics. These changes were also detected by fluorescence spectroscopy. On the other hand, no remarkable changes in total phenolic content and radical scavenging activity were observed. Freeze-drying was studied as a method to encapsulate olive leaf bioactives in amorphous dry carbohydrate matrices. The effect of the carrier formulation and ratio bioactive:carrier on the encapsulation efficiency, the thermal, physical and structural properties of freeze-dried microencapsulated powders was assessed by using a response surface modellig approach. Also, the impact of these factors on the chemical stability of bioactive compounds was studied. Maltodextrin and trehalose were chosen as encapsulating materials as representatives of high and low molecular weight carbohydrates with good glass forming properties for encapsulation purposes. The increasing concentration of maltodextrin enhanced the encapsulation of both total phenolics and oleuropein up to an almost total retention when maltodextrin was used alone, which could be directly observed thanks to fluorescence imaging. Color and thermal properties of the microencapsulated powders depended on the maltodextrin-trehalose ratio and a plasticizing effect of olive leaf extract was also observed, especially in the glassy powders containing maltodextrin. The storage study of unencapsulated and microencapsulated olive leaf extract powders under different physical states revealed that at least for 7 weeks, the chemical stability and antioxidant properties of the bioactives were not affected. Liposomal encapsulation of olive bioactives was investigated, first in model phospholipid membranes by evaluating the effects of oleuropein on membrane thermotropic behavior (differential scanning calorimetry) and ordering and fluidity (fluorescence polarization) in systems with passively encapsulated oleuropein (i.e., added after formation of liposomes) compared to actively encapsulated oleuropein (i.e., encapsulated during formation of liposomes). Also, the antioxidant capacity of oleuropein to inhibit lipid peroxidation. was evaluated under two types of oxidation induction. A potential food ingredient was developed by encapsulating the olive leaf extract in commercial soy phosphatidylcholine, and characterized for its morphological, physical and functional properties in model and real systems (commercial soft drink). Oleuropein and verbascoside were encapsulated with a mean efficiency of 34% and 75%, which indicated that optimization this process can be further investigated to improve the encapsulation. However, liposome encapsulation was effective for a delay of oleuropein degradation at low pH (i.e., pH 2.0), and for the maintenance of oleuropein stability over long periods at refrigeration temperatures and at different pHs. This thus shows that this lipid encapsulation indeed provides a suitable carrier in food systems, such as beverages. Finally, the antioxidant performance of olive leaf extract and other standard and plant extracts was assessed in more challenging and real food processing conditions like those commonly employed during melt-extrusion processing/encapsulation, as opposed to classical liquid antioxidant assays. A simple and novel approach has been proposed to estimate the antioxidant performance under controlled conditions using a lab-scale extruder by implementing a solid-state adaption of the crocin-bleaching liquid assay, based on the bleaching of saffron crocins

3D sound for simulation of arthroscopic surgery

Arthroscopic surgery offers many advantages compared to traditional surgery. Nevertheless, the required skills to practice this kind of surgery need specific training. Surgery simulators are used to train surgeon apprentices to practice specific gestures. In this paper, we present a study showing the contribution of 3D sound in assisting the triangulation gesture in arthroscopic surgery simulation. This ability refers to the capacity of the subject to manipulate the instruments while having a modified and limited view provided by the video camera of the simulator. Our approach, based on the use of 3D sound metaphors, provides interaction cues to the subjects about the real position of the instrument. The paper reports a performance evaluation study based on the perception of 3D sound integrated in the process of training of surgical task. Despite the fact that 3D sound cueing was not shown useful to all subjects in terms of execution time, the results of the study revealed that the majority of subjects who participated to the experiment confirmed the added value of 3D sound in terms of ease of use

Using BCSA Cement to Repair Waterway Transportation Structures

Many maritime structures (e.g., locks, dams, ports) in the US are either reaching or are past their design lives, and there are limited funds for the necessary maintenance activities which can lead to repairs that requires closures. These structures are not easy to detour and often require dewatering before repairs can be made, closures can cause delays and business-related losses which can have a large effect on the nation’s economy. Thus, it is advantageous to reduce the repair time for maritime structures. BCSA (belitic calcium sulfoaluminate) cement is a promising material to perform this type of repair due to its properties. BCSA cement is a fast-setting hydraulic cement capable of reaching compressive strengths greater than 4000 psi (27.6 MPa) in less than 2 hours. BCSA also has low shrinkage and good long-term strengths. This research consisted of developing an optimal rapid-setting underwater mortar mixture design using BCSA cement. Properties such as compressive strength and workability were tested to choose the best mix design. Additionally, soil cements made with BCSA cement were compared to portland cement-based soil cements. These soil cements have applications for rapid repair of levees and earthen dams, but also for rapid soil stabilization. The results obtained prove that BCSA cement is feasible to rapidly perform underwater repairs and repairs of soil-based waterway structures. Keywords: BCSA, underwater, repair, rapid-strength development, soil-cement

Young’s Modulus as a Measurement to Estimate Damage Related with Alkali-Silica Reaction in Concrete.

The main purpose of this research is to compare two nondestructive methods to assess Alkali-Silica reaction (ASR) in concrete. Fifteen concrete prisms were cast using aggregates with different Alkali-Silica reactivity such as Jobe sand and Van Buren sand. The change in strain, shear wave velocity and Young’s modulus were determined according to ASTM C129 and ASTM C215, respectively. This data was collected by Dillon K Self, who determined that the shear wave velocity and strain are inversely proportional. However, when single cracking in the concrete specimen transition to map cracking, the shear wave velocity dropped significantly, whereas the strain value does not. Thus, the shear wave velocity is more sensitive than strain measurements to determine the damage caused by (ASR) in concrete. The Young’s modulus data was analyzed and compared to the results obtained from Self’s experiments using shear wave velocity. Young’s Modulus of the concrete prisms typically follows the same trends as shear wave velocity with strain increasing the Young’s modulus decreases. The percent decrease in Young’s modulus is similar to the percent decrease in shear modulus, and both occur at nearly the same rate and specimen age. Thus, Young’s modulus and shear modulus provide a good estimate to assess concrete conditions

Novel dry state co-milling encapsulation of olive leaf extract

Micro-encapsulation or nano-encapsulation is nowadays representing an interesting strategy to enhance the functionality of bioactives and other biomolecules, serving several purposes such as solubility enhancement, increased gastrointestinal absorption or targeted delivery of bioactive compounds (Li et al., 2015). High energy ball milling is used in the pharmaceutical industry to produce fine dispersions or “molecular alloys” of the active ingredient in a carrier/matrix to enhance solubility and bioavailability (Bandarkar and Vavia, 2011), to produce similar solid dispersion obtained with freeze-dying or spray drying (Willart et al., 2006). Modified starch by ball milling has been applied to encapsulate β-carotene (Roa et al., 2016), but no co-milling in the dry state to encapsulate food bioactives has been implemented yet. Olive leaves phenolic compounds have been widely studied for their health promoting properties (Martín-Peláez et al., 2013) In this work, olive leaf extract (OLE) was co-milled with maltodextrin/maltodextrin-trehalose as carrier, at different ratios and milling treatment time, using a planetary ball-mill. A milling time of 60 min resulted in maximized encapsulation efficiency (95-97%). When a higher ratio of OLE to matrix was applied, encapsulation efficiency was slightly lower compared to lower ratio up to 60 min treatment, but was maximized upon longer treatment. Microstructural analysis of the highly encapsulated OLE dispersions (60-180min) using CLSM microscopy showed fine and homogeneously distributed dispersion of OLE in the internal surface of the maltodextrin/maltodextrin-trehalose matrix. Also in these samples, OLE seemed to be protected from environmental moisture/solvent compared to low encapsulated samples (0-30min) as observed during microscopy analysis. Colour analysis of powder dispersions highlights that co-milling resulted in lighter yellowish homogeneous powders as compared to non-milled, thereby masking the brownish-yellowish colour of OLE. Further experiments are needed to confirm the encapsulation and stabilization of OLE by co-milling with a carrier in order to produce stable ingredients with nutritional and health promoting potential. References BANDARKAR, F. S. & VAVIA, P. R. 2011. An optimized commercially feasible milling technique for molecular encapsulation of meloxicam in beta-cyclodextrin. Drug Dev Ind Pharm, 37, 1318-28. MARTÍN-PELÁEZ, S., COVAS, M. I., FITÓ, M., KUŠAR, A. & PRAVST, I. 2013. Health effects of olive oil polyphenols: Recent advances and possibilities for the use of health claims. Molecular Nutrition & Food Research, 57, 760-771. ROA, D. F., BUERA, M. P., TOLABA, M. P. & SANTAGAPITA, P. R. 2016. Encapsulation and Stabilization of β-Carotene in Amaranth Matrices Obtained by Dry and Wet Assisted Ball Milling. Food and Bioprocess Technology, 10, 512-521. WILLART, J. F., DESCAMPS, N., CARON, V., CAPET, F., DANÈDE, F. & DESCAMPS, M. 2006. Formation of lactose-mannitol molecular alloys by solid state vitrification. Solid State Communications, 138, 194-199

Prediction of Thermal Conductance at Liquid-Gas Interfaces using Molecular Dynamics Simulations

Using Molecular Dynamics (MD) Simulations and Theoretical Calculations, We Study Heat Transfer Across Liquid-Gas Interfaces within a Planar Heat Pipe. to Determine the Thermal Conductance (Kapitza Conductance), GK, at the Interface, Two Heat Transfer Mechanisms, Namely, Conduction and Evaporation/condensation Are Considered. in the Case of Interfacial Heat Conduction, Gas Molecules, Particularly Non-Condensable Gas Molecules, Exchange Heat with Liquid Surfaces through Gas-Liquid Collisions, and the Theoretical Expression for GK is Derived from the Kinetic Theory of Gases. for Interfacial Heat Transfer by Evaporation or Condensation, the Theoretical Expression for GK is Derived from the Schrage Relationships. to Assess the Accuracies of the Theoretical Expressions for GK, We Compare These Theoretical Predictions to the GK Obtained Directly from MD Simulations. for All Cases Studied, the Theoretical Predictions Agree with the MD Simulation Results Very Well. If the Density of Non-Condensable Gas in the Heat Pipe is Much Higher Than that of the Working Fluid in the Gas Phase, We Find that the Interfacial Heat Conduction Could Contribute Significantly to the Total Heat Flux Across the Liquid-Gas Interfaces. the Effect of GK at Liquid-Gas Interfaces on the overall Heat Transfer Efficiency in a Planar Heat Pipe is Discussed