Do Different Groups Invest Differently in Higher Education?

On average, education accounts for about 2 percent of total annual expenditures by U.S. consumers, but this percentage varies greatly by demographic. Some groups appear to spend much more than others, so it is natural to question what influences this variation in spending. A popular conception is that racial and ethnic groups value higher education differently. In economic terms, this is a reflection of the value of human capital—how much people are willing to invest in their children’s education. The notion that some groups invest more than others is often based on average participation rates but does not account for actual expenditures or the expenditures when you consider socioeconomic differences. This Beyond the Numbers article looks at the amount of money invested in education by different race and ethnic groups and examines different factors that could contribute to the differences in expenditures. We find that race and ethnicity groups do, on average, spend vastly different amounts on education, but the likelihood of going to college (and thus having education expenditures) and socioeconomic factors have the most influence on families’ investment in higher education—and race and ethnicity is not the driving factor, as commonly thought

A new model for the double well potential

A new model for the double well potential is presented in the paper. In the new potential, the exchanging rate could be easily calculated by the perturbation method in supersymmetric quantum mechanics. It gives good results whether the barrier is high or sallow. The new model have many merits and may be used in the double well problem.Comment: 3pages, 3figure

T cell cross-reactivity between coxsackievirus and glutamate decarboxylase is associated with a murine diabetes susceptibility allele.

Limited regions of amino acid sequence similarity frequently occur between microbial antigens and host proteins. It has been widely anticipated that during infection such sequence similarities could induce cross-reactive T cell responses, thereby initiating T cell-mediated autoimmune disease. However, the nature of major histocompatibility complex (MHC)-restricted antigen presentation confers a number of constraints that should make this type of T cell cross-reactivity a rare, MHC allele-dependent event. We tested this prediction using two insulin-dependent diabetes mellitus (IDDM)-associated antigens, coxsackievirus P2-C (Cox P2-C) protein and glutamate decarboxylase (GAD65), which share a prototypic sequence similarity of six consecutive amino acids within otherwise unrelated proteins. We surveyed a panel of 10 murine MHC class II alleles that encompass the spectrum of standard alleles for the ability to cross-reactively present Cox P2-C and GAD65. Out of the 10 restriction elements tested, the sequence similarity regions were both dominant determinants and were cross-reactively displayed after the natural processing of whole antigens, only in the context of I-Anod. These data show that cross-reactive T cell recognition of sequence similarity regions in unrelated proteins is confined to certain MHC alleles, which may explain MHC association with autoimmune disease. It is striking that these two diabetes-associated antigens were cross-reactively recognized only in the context of a diabetes susceptibility allele. Since the human and the murine class II alleles associated with IDDM share conserved features, cross-reactive T cell recognition of GAD65 and Cox P2-C may contribute to the pathogenesis of human IDDM and account for the epidemiological association of coxsackievirus with IDDM

Pulsars identified from the NRAO VLA Sky Survey

We identified 97 strong pulsars from the NRAO VLA Sky Survey (NVSS) at 1.4 GHz north of Dec(J2000) >-40\degr. The total flux density, linear polarization intensity and polarization angle (PA) of all pulsars are extracted from the NVSS catalog. The well-calibrated PA measurement of 5 pulsars can be used for absolute PA calibrations in other observations. Comparing the source positions with those in the pulsar catalog, we got the first measurement of the proper motion upper limit of PSR B0031-07, which is $\mu_{\alpha}\cos\delta = -102 \pm 74 mas/yr$ and $\mu_{\delta} = -105 \pm 78 mas/yr$.Comment: 7 pages; 3 figures; one big table; To appear in A&A Supplement

Solar transition region in the quiet Sun and active regions

The solar transition region (TR), in which above the photosphere the tempera- ture increases rapidly and the density drops dramatically, is believed to play an important role in coronal heating and solar wind acceleration. Long-lasting up-flows are present in the upper TR and interpreted as signatures of mass supply to large coronal loops in the quiet Sun. Coronal bright points (BPs) are local heating phenomena and we found a different Doppler-shift pattern at TR and coronal temperatures in one BP, which might be related to the twisted loop system. The dominant energy loss in the lower TR is the Ly-alpha emission. It has been found that most Ly-alpha radiance profiles are stronger in the blue peak, an asymmetry opposite to higher order Lyman lines. This asymmetry is stronger when the downflow in the middle TR is stronger, indicating that the TR flows play an important role in the line formation process. The peak separation of Ly-alpha is found to be larger in coronal holes than in the quiet Sun, reflecting the different magnetic structures and radiation fields between the two regions. The Lyman line profiles are found to be not reversed in sunspot plume and umbra regions, while they are obviously reversed in the surrounding plage region. At TR temperatures, the densities of the sunspot plume and umbra are a factor of 10 lower than of the plage, indicating that the sunspot plasma emitting at TR temperatures is higher and possibly more extended above sunspots than above the plage region.Comment: This paper has been withdrawn by the author because it's not a referred pape

CAN FOOD PROCESSORS USE CONTRACTS TO INFLUENCE FARM CASH PRICES? THE COMPETITIVE IMPLICATIONS OF TOP-OF-THE-MARKET AND RELATED PRICING CLAUSES

When contract production is marketed contemporaneously with production sold through a spot market, it is conveninet to specify the contract price in terms of the subsequent cash price. This paper examines the competitive implications of such pricing arrangements, focusing in particular upon so-called "top-of-the-market (TOMP) pricing in cattle procurement, wherein the contract guarantees the producer the highest cash price prevailing at the time of delivery. We show that these contracts have anticompetitive consequences when the same buyers who purchase cattle with the TOMP clause also compete to procure cattle in the subsequent spot market. By committing to purchase cattle at a price to be determined later, beef packers' incentives to compete aggressively in the spot market are attenuated. Although TOMP pricing is not in producers' collective interest, rational sellers may nonetheless sign these contracts, in some cases with little or no financial inducement.Demand and Price Analysis,