Evolved gas analysis of hydrated phases in Murchison and Orgueil

To better characterise the hydrated minerals in chondrites Evolved Gas Analysis of Murchison, Orgueil and selected minerals has been carried out. Meteorite water release profiles show significant differences to expected reference minerals

The oxygen isotopic composition of water extracted from unequilibrated ordinary chondrites

The oxygen isotopic composition of water extracted from the unequilibrated ordinary chondrites Semarkona and Bishunpur reveals differences in alteration mineralogy and levels of isotopic enrichment – reflecting key parameters in the alteration process

Immigration, Offshoring and American Jobs

How many \"American jobs\" have U.S.-born workers lost due to immigration and offshoring? Or, alternatively, is it possible that immigration and offshoring, by promoting cost-savings and enhanced efficiency in firms, have spurred the creation of jobs for U.S. natives? We consider a multi-sector version of the Grossman and Rossi-Hansberg (2008) model with a continuum of tasks in each sector and we augment it to include immigrants with heterogeneous productivity in tasks. We use this model to jointly analyze the impact of a reduction in the costs of offshoring and of the costs of immigrating to the U.S. The model predicts that while cheaper offshoring reduces the share of natives among less skilled workers, cheaper immigration does not, but rather reduces the share of offshored jobs instead. Moreover, since both phenomena have a positive \"cost-savings\" effect they may leave unaffected, or even increase, total native employment of less skilled workers. Our model also predicts that offshoring will push natives toward jobs that are more intensive in communication-interactive skills and away from those that are manual and routine intensive. We test the predictions of the model on data for 58 U.S. manufacturing industries over the period 2000-2007 and find evidence in favor of a positive productivity effect such that immigration has a positive net effect on native employment while offshoring has no effect on it. We also find some evidence that offshoring has pushed natives toward more communication-intensive tasks while it has pushed immigrants away from them.Employment, production tasks, immigrants, offshoring

Immigration, Offshoring and American Jobs

How many "American jobs" have U.S.-born workers lost due to immigration and offshoring? Or, alternatively, is it possible that immigration and offshoring, by promoting cost-savings and enhanced efficiency in firms, have spurred the creation of jobs for U.S. natives? We consider a multi-sector version of the Grossman and Rossi-Hansberg (2008) model with a continuum of tasks in each sector and we augment it to include immigrants with heterogeneous productivity in tasks. We use this model to jointly analyze the impact of a reduction in the costs of offshoring and of the costs of immigrating to the U.S. The model predicts that while cheaper offshoring reduces the share of natives among less skilled workers, cheaper immigration does not, but rather reduces the share of offshored jobs instead. Moreover, since both phenomena have a positive "cost-savings" effect they may leave unaffected, or even increase, total native employment of less skilled workers. Our model also predicts that offshoring will push natives toward jobs that are more intensive in communication-interactive skills and away from those that are manual and routine intensive. We test the predictions of the model on data for 58 U.S. manufacturing industries over the period 2000-2007 and find evidence in favor of a positive productivity effect such that immigration has a positive net effect on native employment while offshoring has no effect on it. We also find some evidence that offshoring has pushed natives toward more communication-intensive tasks while it has pushed immigrants away from them.Employment, Production tasks, Immigrants, Offshoring

Continued investigation of the light element geochemistry of Tagish Lake

We have determined the abundance and isotopic composition of two separate carbonate generations within Tagish Lake. Nitrogen isotope analysis of the chondrite shows it to be organic-rich, with d15N values higher than in CI and CM chondrites

Immigration, offshoring and American jobs

How many "American jobs" have U.S.-born workers lost due to immigration and offshoring? Or, alternatively, is it possible that immigration and offshoring, by promoting cost-savings and enhanced efficiency in firms, have spurred the creation of jobs for U.S. natives? We consider a multi-sector version of the Grossman and Rossi-Hansberg (2008) model with a continuum of tasks in each sector and we augment it to include immigrants with heterogeneous productivity in tasks. We use this model to jointly analyze the impact of a reduction in the costs of offshoring and of the costs of immigrating to the U.S. The model predicts that while cheaper offshoring reduces the share of natives among less skilled workers, cheaper immigration does not, but rather reduces the share of offshored jobs instead. Moreover, since both phenomena have a positive "cost-savings" effect they may leave unaffected, or even increase, total native employment of less skilled workers. Our model also predicts that offshoring will push natives toward jobs that are more intensive in communication-interactive skills and away from those that are manual and routine intensive. We test the predictions of the model on data for 58 U.S. manufacturing industries over the period 2000-2007 and find evidence in favor of a positive productivity effect such that immigration has a positive net effect on native employment while offshoring has no effect on it. We also find some evidence that offshoring has pushed natives toward more communication-intensive tasks while it has pushed immigrants away from them.Employment, production tasks, immigrants, offshoring

Space weathering: Laboratory analyses and in-situ instrumentation

Simulations of space weathering using laser irradiation are exploited to study the formation of sub-microscopic iron. A variety of magnetic techniques are evaluated to characterise this iron and are considered for in-situ instrumentation

Magmatic carbon in Martian meteorites: attempts to constrain the carbon cycle on Mars

One of the current goals of Martian exploration is to find evidence for extinct (or even extant) life. Carbon (an essential ingredient of life on Earth) is known to occur on Mars as CO2 in the atmosphere and frozen in the polar caps; it is inferred to be present as carbonates in the Martian crust and soils. We are attempting to define and quantify the different carbon reservoirs on Mars, so that we can follow Mars' carbon cycle. This paper discusses a primordial magmatic component that could be the starting point of such a cycle. The nature, distribution and isotopic composition of carbon was measured in a suite of Martian meteorites, comprising Chassigny and 11 shergottites. Other Martian meteorites were not included, as they sample rocks that have been altered by fluids at Mars' surface. Our results, obtained by high-resolution stepped combustion and mass spectrometry, show that the magmatic component has a very variable abundance of 1–100 ppm, with [delta]13C~[minus sign]20±4‰. This value is close to magmatic carbon determined for Moon and for Vesta (the parent body of the HED basaltic meteorites), but very different from that of Earth