Trade Adjustment: Worker Level Evidence

In the past two decades, China’s manufacturing exports have grown spectacularly, U.S. imports from China have surged, but U.S. exports to China have increased only modestly. Using representative, longitudinal data on individual earnings by employer, we analyze the effect of exposure to import competition on earnings and employment of U.S. workers over 1992 through 2007. Individuals who in 1991 worked in manufacturing industries that experienced high subsequent import growth garner lower cumulative earnings and are at elevated risk of exiting the labor force and obtaining public disability benefits. They spend less time working for their initial employers, less time in their initial two-digit manufacturing industries, and more time working elsewhere in manufacturing and outside of manufacturing. Earnings losses are larger for individuals with low initial wages, low initial tenure, low attachment to the labor force, and those employed at large firms with low wage levels. Import competition also induces substantial job churning among high-wage workers, but they are better able than low-wage workers to move across employers with minimal earnings losses, and are less likely to leave their initial firm during a mass layoff. These findings, which are robust to a large set of worker, firm and industry controls, and various alternative measures of trade exposure, reveal that there are significant worker-level adjustment costs to import shocks, and that adjustment is highly uneven across workers according to their conditions of employment in the pre-shock period

Magnetic structures in Pr6Ni2Si3 and Pr5Ni2Si3

The temperature dependence of magnetization in Pr6Ni2Si3 and Pr5Ni2Si3 compounds has been studied with the objective of providing a theoretical understanding of the behavior of the magnetic properties of the material. The ternary Pr–Ni–Si system contains the homologous series of compounds R(n+2)(n+1)Nin(n−1)+2Sin(n+1), where R is a rare earth element which provides a range of materials with different but related structures. The crystal structures and unit cells of Pr6Ni2Si3 (n=2) and Pr5Ni2Si3 (n=3) compounds are closely related consisting of an overall hexagonal structure comprising trigonal columns of atoms, in which the only difference is in the size of the triangular base of the column which depends directly on the chemical composition, specifically the index n. The calculations were based on a nearest neighbor exchange interaction approximation under two kinds of conditions: collinear and noncollinear magnetic structures. The results of these calculations show the Curie temperature, but do not yet predict quantitatively the spin reorientation transition at lower temperatures

Theoretical calculation of magnetic structure variation in Pr5Ni2Si3

The variation of magnetization with temperature of the Pr5Ni2Si3 compound was calculated using a nearest neighbor exchange interaction approximation. Pr atoms, which are the only element in this compound with a net magnetic moment, were classified into three types based on the number of nearest neighbor exchange interactions. The expected magnetization versus temperature curve for each type of Pr atom was calculated using the Brillouin function, as well as the average magnetization versus temperature curve for the entire unit cell. The results show that the “corner” atoms exhibit very different behavior from that of the other types of Pr atoms on the “center” or “edge” sites. This is due to the broken symmetry in exchange interaction at the corner site due to interactions with atoms from outside the unit cell that are in closer proximity than atoms within the unit cell. This is considered to be the cause of a second magnetic phase transition observed at a lower temperature than the Curie temperature

Prostaglandins A1 and E1 influence gene expression in an established insect cell line (BCIRL-HzAM1 cells)

Prostaglandins (PGs) and other eicosanoids exert important physiological actions in insects and other invertebrates, including influencing ion transport and mediating cellular immune defense functions. Although these actions are very well documented, we have no information on the mechanisms of PGs actions in insect cells. Here we report on the outcomes of experiments designed to test our hypothesis that PGs modulate gene expression in an insect cell line established from pupal ovarian tissue of the moth Helicoverpa zea (BCIRL-HzAM1 cells). We treated cells with either PGA1 or PGE1 for 12 or 24 h then analyzed cell lysates by 2-D electrophoresis. Analysis of the gels by densitometry revealed substantial changes in protein expression in some of the protein spots we analyzed. These spots were processed for mass spectrometric analysis by MALDI TOF/TOF, which yielded in silico protein identities for all 34 spots. The apparent changes in three of the proteins were confirmed by semi-quantative PCR, showing that the changes in mRNA expression were reflected in changes in protein expression. The 34 proteins were sorted into six categories, protein actions, lipid metabolism, signal transduction, protection, cell functions and metabolism. The findings support the hypothesis that one mechanism of PG action in insect cells is the modulation of gene expression

Temperature dependence of magnetic anisotropy of Ga-substituted cobalt ferrite

The temperature dependence of magnetization, magnetic anisotropy, and coercive field of gallium-substituted cobaltferrite was investigated for a series of compositions of CoGaxFe2−xO4 (0⩽x⩽0.8). Hysteresis loops were measured for each sample over the range of −5T⩽μ0H⩽5T for selected temperatures between 10 and 400K. The magnetization at 5T and low temperatures was found to increase for the lower Ga contents (x=0.2 and 0.4) compared to pure CoFe2O4, indicating that at least initially, Ga3+substitutes predominantly into the tetrahedral sites of the spinel structure. The high field regions of these loops were modeled using the law of approach to saturation, which represents the rotational process, together with an additional linear forced magnetization term. The first order cubic magnetocrystalline anisotropy coefficient K1 was calculated from curve fitting to these data. It was found that K1 decreased with increasing Ga content at all temperatures. Both anisotropy and coercivity increased substantially as temperature decreased. Below 150K, for certain compositions (x=0, 0.2, 0.4), the maximum applied field of μ0H=5T was less than the anisotropy field and, therefore, insufficient to saturate the magnetization. In these cases, the use of the law of approach method can lead to calculated values of K1 which are lower than the correct value

EGF-stimulation activates the nuclear localization signal of SHP-1

Protein tyrosine phosphatase SHP-1 plays a critical role in the regulation of a variety of intracellular signaling pathways. SHP-1 is predominantly expressed in the cells of hematopoietic origin, and is recognized as a negative regulator of lymphocyte development and activation. SHP-1 consists of two Src homology 2 (SH2) domains and one protein tyrosine phosphatase (PTP) domain followed by a highly basic C-terminal tail containing tyrosyl phosphorylation sites. It is unclear how the C-terminal tail regulates SHP-1 function. We report the examination of the subcellular localization of a variety of truncated or mutated SHP-1 proteins fused with enhanced green fluorescent protein (EGFP) protein at either the N-terminal or the C-terminal end in different cell lines. Our data demonstrate that a nuclear localization signal (NLS) is located in the C-terminal tail of SHP-1 and the signal is primarily defined by three amino-acid residues (KRK) at the C-terminus. This signal is generally blocked in the native protein and can be exposed by fusing EGFP at the appropriate position or by domain truncation. We have also revealed that this NLS of SHP-1 is triggered by epidermal growth factor (EGF) stimulation and mediates translocation of SHP-1 from the cytosol to the nucleus in COS7 cell lines. These results not only demonstrate the importance of the C-terminal tail of SHP-1 in the regulation of nuclear localization, but also provide insights into its role in SHP-1-involved signal transduction pathways. © 2004 Wiley-Liss, Inc

Entanglement Swapping Chains for General Pure States

We consider entanglement swapping schemes with general (rather than maximally) entangled bipartite states of arbitary dimension shared pairwise between three or more parties in a chain. The intermediate parties perform generalised Bell measurements with the result that the two end parties end up sharing a entangled state which can be converted into maximally entangled states. We obtain an expression for the average amount of maximal entanglement concentrated in such a scheme and show that in a certain reasonably broad class of cases this scheme is provably optimal and that, in these cases, the amount of entanglement concentrated between the two ends is equal to that which could be concentrated from the weakest link in the chain.Comment: 18 pages, 5 figure

A New Method to Identify Nearby, Young, Low-mass Stars

We describe a new method to identify young, late-type stars within ~150 pc of the Earth that employs visual or near-infrared data and the GALEX GR4/5 database. For spectral types later than K5, we demonstrate that the ratio of GALEX near-ultraviolet (NUV) to visual and near-IR emission is larger for stars with ages between 10 and 100 Myr than for older, main sequence stars. A search in regions of the sky encompassing the TW Hya and Scorpius-Centaurus Associations has returned 54 high-quality candidates for followup. Spectroscopic observations of 24 of these M1-M5 objects reveal Li 6708 angstrom absorption in at least 17 systems. Because GALEX surveys have covered a significant fraction of the sky, this methodology should prove valuable for future young star studies.Comment: 27 pages, 8 figures, accepted for publication in ApJ. Some significant changes were made in proof, we recommend readers use the ApJ versio