Interregional migration in The Netherlands: an aggregate analysis

The understanding of migration behaviour is of key importance for regional population forecasting. This paper studies the phenomenon empirically, the results are to be applied in a regional labour market model that forecasts the spatial distribution of employment and labour force in the long term. Therefore, we pay particular attention to the impact of local labour market developments. Population forecasting demands for a macro approach to migration. However, certain relations that appear evident from microanalyses are difficult to trace in aggregate data. There are two ways in which we deal with this problem. We distinguish seven age groups. Since some migration motives (like education) are associated with particular age groups, we get a clearer picture of underlying mechanisms. Secondly, we expect that the share of labour motivated migrations in the flow between two regions increases with the distance between them. We therefore consider the impact of explanatory variables both on short and on longer distances. We split the migration decision into a decision to move and a choice of destination. For each age group, we propose a generation model based on population characteristics, that projects the total number of movers per region. The distribution of these migrants is determined by means of a production constrained spatial interaction model. Explanatory variables cover housing, labour market and study motives. Housing market related variables dominate short distance moves. Our estimation results show that labour market variables indeed play a significant role in describing long distance moves of young adults.

Equine digital tendons show breed‐specific differences in their mechanical properties that may relate to athletic ability and predisposition to injury

Background Throughout the ages, human subjects have selected horse breeds for their locomotor capacities. Concurrently, tissue properties may have diversified because of specific requirements of different disciplines. Objectives The aim of this study was to compare the biomechanical properties of tendons with different functions between equine breeds traditionally selected for racing or sport. Study design This study used ex vivo tendons and compared the mechanical properties of the common digital extensor tendon (CDET) and superficial digital flexor tendon (SDFT) between racehorses (Thoroughbred [TB]) and sports horses (Friesian Horse [FH], Warmblood [WB]). Methods The SDFT and CDET of FH (n = 12), WBs (n = 12) and TBs (n = 8) aged 3-12 years were harvested. The cross sectional area (cm(2)), maximal load (N), ultimate strain (%), ultimate stress (MPa) and elastic modulus (MPa) were determined and tested for significant differences between the breeds (P<0.05). Results The SDFT from WB horses had a significantly lower elastic modulus than TB horses and failed at a higher strain and load than both FHs and TBs. The mechanical properties of the CDET did not differ between breeds. In agreement with previous studies, the CDET failed at a higher stress and had a higher elastic modulus than the SDFT and, for the WB group of horses only, failed at a significantly lower strain. Interestingly, the mode of failure differed between breeds, particularly with respect to the FHs. Main limitations The exercise history of horses used in this study was unknown and the age-range was relatively large; both these factors may have influenced the absolute properties reported in this study. Conclusions This study shows for the first time that mechanical properties of the SDFT differ between breeds. These properties are likely to be related to selection for high-speed vs. an extravagant elastic gait and may be an important indicator of performance ability. The is available in Spanish - see Supporting Informatio

Prophosphatrane compounds as proton abstracting reagents

Prophosphatrane compounds of the formula ##STR1## are disclosed. These compounds are strong Lewis bases and are useful as proton abstracting reagents

Converting homogeneous to heterogeneous catalysts

Homogeneous transition metal complex catalysts for organic industrial processes are converted to catalysts which are heterogeneous with respect to the reactants, and which have substantially equal catalytic activity to the homogeneous catalysts. This is done by reacting a normally homogeneous transition metal complex catalyst with a metal bridging ligand which substantially duplicates the ligand moiety of the metal complex, to provide a polymerized, normally solid, heterogeneous phase, transition metal complex catalyst

Method for synthesis of triarylisocyanurates from aryl isocyanates using triazaprophosphatrane catalysts

A method is provided to prepare triaryl isocyanurates from aryl isocyanates by using triazaprophosphatrane catalyst

The spectrum of Progressive Familial Intrahepatic Cholestasis diseases:Update on pathophysiology and emerging treatments

The Progressive Familial Intrahepatic Cholestasis (PFIC) disease spectrum encompasses a variety of genetic diseases that affect the bile production and the secretion of bile acids. Typically, the first presentation of these diseases is in early childhood, frequently followed by a severe course necessitating liver transplantation before adulthood. Except for transplantation, treatment modalities have been rather limited and frequently only aim at the symptoms of cholestasis, such as cholestatic pruritus. In recent years, progress has been made in understanding the pathophysiology of these diseases and new treatment modalities have been emerging. Herewith we summarize the latest developments in the field and formulate the current key questions and opportunities for further progress

Preparation of pyrrol and oxazole compounds; formation of porphyrins and C-acyl-α-amino acid esters therefrom

A process for preparation of new or previously known pyrrol derivatives is provided. The process involves reacting a nitroalkane or a nitroalkene with an isocyanoacetate in the presence of a prophosphatrane super base to prepare the pyrrol compounds. Through production of new pyrrol compounds, new pyrrol derivatives such as dipyrromethanes and porphyrins may be synthesized. In addition, the high yields of pyrrol compounds produced according to the method of the invention provide for more efficient production of previously known dipyrromethane and porphyrin compounds. The invention further provides a mild, high yield process for de-esterification of esterified pyrrol and dipyrromethane compounds. The invention also provides a synthetic method for the production of high yields of oxazoles through reaction of an aryl halide or acid anhydride with an isocyanoacetate in the presence of a prophosphatrane super base . The product oxazoles serve as intermediates for subsequent treatment to provide pharmaceutically interesting C-acyl-α-amino acid esters