Salary Schedules, Teacher Sorting, and Teacher Quality

This study investigates how salary rigidities affect teacher quality across teaching subjects and high schools and whether high quality teachers can be compensated sufficiently to attract them into unfavorable schools. For identification, we rely on idiosyncratic variations in compensation across adjacent districts within the same state. The results indicate that, on average, math/science teachers’ scholastic aptitudes are 8.5 percentiles lower and humanities teachers are 4.5 percentiles lower compared to other teachers. Furthermore, we find that schools with higher percentages of student eligible for free lunch hire teachers with, on average, 7 to 17 percentiles lower scholastic aptitudes with the math/science teachers being even lower. Increases in lifetime compensation is found to raise the scholastic aptitude of teachers hired across all schools, with diminishing returns in schools with more favorable working conditions. However, the lower 26% of the teacher aptitude distribution seems to not respond to compensation at all with only marginal gains up to the 60th percentile. Furthermore, bonus/merit pay or additional school activity income do not seem to be significant in recruiting/retaining high aptitude teachers.

Reevaluating the Effect of Non-Teaching Wages on Teacher Attrition

Most researchers find that the non-teaching wage has a significant effect on teacher attrition. Surprisingly no study that estimates this effect actually uses former teachers? wages. The use of aggregate wage data can potentially cause upward bias coefficients due to selection issues. Using wages of former teachers in a simultaneous probit-tobit system of equations, the effect is estimated and found to be insignificant. The results indicate that higher teaching wages and student teaching significantly lower attrition while being attacked or threatened during the previous school year and whether the teacher lives in a household with income above $40,000 significantly increase attrition.

Voices from the margins: ‘Black’ Caribbean and Mexican heritage women educators in the rural south

This paper explores the ways in which immigrant and migrant women educators in the rural South understand and construct narratives of their lives. The ‘Black’ Caribbean and Mexican heritage women educators in this study experience and interpret events in their lives, as women, minorities, postcolonial ‘subjects,’ and outsiders in the rural South, a region traditionally dominated by white patriarchal norms and prejudices. We assert that from this position of multiple marginality they construct important insights into the nature of education in the rural South. As so-called “Third-World women” living in the “First World” of the United States, the interpretations that this group of immigrant and migrant women make of their lives illuminate the ‘real,’ yet fluid (Moya & Hames-Garcia, 2000), nature of identity and representation in this nation and in the “New” South. The experiences of these women clearly reveal that identity categories provide useful theoretical and practical understandings of often problematic constructs such as race, gender, social class and ethnicity and highlight the fact that experiences and interpretations vary within and across these identity categories. Thus, how these women respond to the South demonstrates the impact of significant continuities and discontinuities as these educators negotiate their identities in unfamiliar spaces

Stress corrosion cracking of titanium alloys at ambient temperature in aqueous solutions Progress report, Jun. - Aug. 1966

Stress corrosion cracking of titanium alloys at ambient temperature in aqueous solutio

The Impact of the Internet on Information Searching and Demand for Traditional Information Resources

The Internet is an efficient information search tool whose growth may have caused a structural change in information search and acquisition behaviors. This study investigates the effects of growing Internet accessibility on these behaviors. Using U.S. public library circulation counts to quantify changes in the use of information resources, the analysis indicates that greater Internet accessibility contributes to increased demand for traditional information sources. That is, a complementary relationship exists between Internet and traditional sources. Further, the results suggest that limiting Internet access can reduce the demand for traditional content. These outcomes imply that improvements in Internet accessibility can have profound effects on human capital development.

The Quantity and Quality of Teachers: A Dynamic Trade-off

We study the dynamics of the quantity and quality of teachers in the framework of dynamic general equilibrium OLG model. The quantity and quality are jointly set by a government agency wishing to maximize the quality of basic education per student while being bound by teachers’ collective bargaining agreement which equalizes teacher pay. Our model features two stages of education: basic and advanced (college), the latter being required of teachers. The cost of hiring teachers is influenced by the outside opportunities that college educated individuals have in the production sector. We show that this factor strengthens in the process of endogenous growth and moreover that it pushes the optimal trade-off between quantity and quality of teachers in the direction of the former. Namely, the number of teachers hired will grow over time while their relative quality (but not the absolute human capital attainment) will fall. This evolution of human capital accumulation is accompanied by increasing inequality, within the group of college educated workers in particular. Further, we consider the comparative dynamics effect of an exogenous skill biased technological change represented by a positive shock to productivity of the skilled workers, hence to the college premium. We show that this will exacerbate the negative trends in the quality of basic education in relation to GDP growth. Countering this trend would therefore require an increase in the share of GDP spent on basic education, assuming that the institutional setup of the school system remains unchanged.basic and college education, skill premium, student-teacher ratio

Large amplitude electrothermal waves in a nonequilibrium plasma

Steady, one-dimensional current streamers have been observed in nonequilibrium plasma subjected to crossed E and B fields. Their half-width and amplitude agree with a nonlinear model of electrothermal waves

Identification and expression analysis of CBF/DREB1 and COR15 genes in mutants of Brassica oleracea var. botrytis with enhanced proline production and frost resistance.

Frost resistant mutants of Brassica oleracea var. botrytis were investigated for the presence of CBF/DREB1 and COR15a gene products and induced frost resistance. Total RNA of clones was isolated after 3 h, 6 h, 24 h and 14 d acclimation at 4 °C and proteins and free proline were isolated after 14 d acclimation. cDNA was produced using RT-PCR and the first CBF gene in B. oleracea detected and did quantify. Through SDS-PAGE and Western blotting, the COR15a protein was detected for the first time in B. oleracea. The results confirmed the first report of the presence of BoCBF/DREB1 in B. oleracea and this only appeared under cold acclimation. The sequence analysis of predicted amino acids revealed a very high homology (90%) with CBF sequences of other Brassica species (BnCBF5/DREB1, BrDREB1 and BjDREB1B) and homology reduced to 67% when compared to plants other than Brassicas. BoCBF/DREB1 transcript levels increased up to 24 h acclimation and then declined. Some mutants showed BoCBF/DREB1 expression at 3 h while others only after 6 h and 24 h acclimation. The genotypes showed positive significant correlation between BoCBF/DREB1 expression and frost resistance (R(2) = 0.9343). The proline level under acclimation increased about 8 fold and demonstrated positive and significant correlation with BoCBF/DREB1 expression. Proline also showed positive and significant correlation with frost resistance under cold acclimation but very not under non-acclimation. All clones were positive for COR15a protein after 14 d cold acclimation and expression correlated with frost resistance. Under non-acclimation COR15a was constitutively expressed in 3 mutants

Rapid behavioral transitions produce chaotic mixing by a planktonic microswimmer

Despite their vast morphological diversity, many invertebrates have similar larval forms characterized by ciliary bands, innervated arrays of beating cilia that facilitate swimming and feeding. Hydrodynamics suggests that these bands should tightly constrain the behavioral strategies available to the larvae; however, their apparent ubiquity suggests that these bands also confer substantial adaptive advantages. Here, we use hydrodynamic techniques to investigate "blinking," an unusual behavioral phenomenon observed in many invertebrate larvae in which ciliary bands across the body rapidly change beating direction and produce transient rearrangement of the local flow field. Using a general theoretical model combined with quantitative experiments on starfish larvae, we find that the natural rhythm of larval blinking is hydrodynamically optimal for inducing strong mixing of the local fluid environment due to transient streamline crossing, thereby maximizing the larvae's overall feeding rate. Our results are consistent with previous hypotheses that filter feeding organisms may use chaotic mixing dynamics to overcome circulation constraints in viscous environments, and it suggests physical underpinnings for complex neurally-driven behaviors in early-divergent animals.Comment: 20 pages, 4 figure