Does It Pay To Attend An Elite Private College? Cross Cohort Evidence on the Effects of College Quality on Earnings

While there is evidence of a substantial and rising labor market premium associated with college attendance, little is known about how this premium varies across institutions of different quality and across time. Previous research which has estimated the return to college quality has not taken into account that individuals likely select the type of college they attend based in part on the expected economic return and net costs. In this paper we explicitly model high school students' choice of college type (characterized by quality and control) based on individual and family characteristics (including ability and parental economic status), and an estimate of the net costs of attendance and expected labor market return. We estimate selectivity corrected outcome equations, using data from both the National Longitudinal Study of the High School Class of 1972 and High School and Beyond, which permit us to determine the effects of college quality on wages and earnings and how this effect varies across time. Even after controlling for selection effects there is strong evidence of significant economic return to attending an elite private institution, and some evidence that this premium has increased over time.

Characterization of FRO\u3csub\u3e1\u3c/sub\u3e, a Pea Ferric-Chelate Reductase Involved in Root Iron Acquisition

To acquire iron, many plant species reduce soil Fe(III) to Fe(II) by Fe(III)-chelate reductases embedded in the plasma membrane of root epidermal cells. The reduced product is then taken up by Fe(II) transporter proteins. These activities are induced under Fe deficiency. We describe here the FRO1 gene from pea (Pisum sativum), which encodes an Fe(III)-chelate reductase. Consistent with this proposed role, FRO1 shows similarity to other oxidoreductase proteins, and expression of FRO1 in yeast conferred increased Fe(III)-chelate reductase activity. Furthermore, FRO1 mRNA levels in plants correlated with Fe(III)-chelate reductase activity. Sites of FRO1 expression in roots, leaves, and nodules were determined. FRO1 mRNA was detected throughout the root, but was most abundant in the outer epidermal cells. Expression was detected in mesophyll cells in leaves. In root nodules, mRNA was detected in the infection zone and nitrogen-fixing region. These results indicate that FRO1 acts in root Fe uptake and they suggest a role in Fe distribution throughout the plant. Characterization of FRO1 has also provided new insights into the regulation of Fe uptake. FRO1 expression and reductase activity was detected only in Fe-deficient roots of Sparkle, whereas both were constitutive in brz and dgl, two mutants with incorrectly regulated Fe accumulation. In contrast, FRO1 expression was responsive to Fe status in shoots of all three plant lines. These results indicate differential regulation of FRO1 in roots and shoots, and improper FRO1 regulation in response to a shoot-derived signal of iron status in the roots of the brz and dgl mutants

Homocysteine Levels, Haemostatic Risk Factors and Patency Rates after Endovascular Treatment of the Above-Knee Femoro-Popliteal Artery

AbstractObjectives. To investigate the relationship between plasma homocysteine and other haemostatic variables and restenoses or reocclusions after endovascular treatment of symptomatic atherosclerosis of the above-knee femoro-popliteal artery.Design. Prospective observational study.Setting. University hospital.Patients and methods. The study included 103 patients (116 limbs), treated with subintimal angioplasty in 58 cases (50%) and with intraluminal PTA in 58 (50%): 39 (34%) patients were treated for critical limb ischaemia. Blood samples for analyses of fasting plasma values of homocysteine, fibrinogen, D-dimer, activated protein C resistance were drawn upon admission. Median follow-up for all procedures was 11 months (range 0–42 months). Outcome events (arterial patency) were defined as ≥50% restenosis or reocclusion in the treated arterial segment. Patency rates were estimated with the product limit method and Kaplan–Meier curves. Variables found to be related significantly to patency were included in multivariate analysis performed with the Cox proportional hazard model.Results. The 1-year cumulative primary patency rate for all procedures was 48%. One-year limb salvage rate in cases of critical ischaemia was 74%. Multivariate analysis demonstrated significant independent associations between patency rates and plasma D-dimer, diabetes mellitus, the nature of the lesion treated (stenosis vs. occlusion) and antithrombotic therapy with aspirin after the procedure. Plasma levels of homocysteine, fibrinogen or activated protein C resistance were not associated with patency rates. Homocysteine levels were higher in patients with critical limb ischaemia than those with intermittent claudication.Conclusions. Early restenosis or reocclusion after endovascular intervention of lesions in the above-knee femoro-popliteal artery was more frequent following treatment of occlusion (versus stenosis), for patients with diabetes, patients with elevated D-dimer and those without antithrombotic therapy after the procedure. Plasma homocysteine did not appear to influence the outcome of endovascular intervention

Gestational age at delivery and special educational need: retrospective cohort study of 407,503 schoolchildren

<STRONG>Background</STRONG> Previous studies have demonstrated an association between preterm delivery and increased risk of special educational need (SEN). The aim of our study was to examine the risk of SEN across the full range of gestation. <STRONG>Methods and Findings</STRONG> We conducted a population-based, retrospective study by linking school census data on the 407,503 eligible school-aged children resident in 19 Scottish Local Authority areas (total population 3.8 million) to their routine birth data. SEN was recorded in 17,784 (4.9%) children; 1,565 (8.4%) of those born preterm and 16,219 (4.7%) of those born at term. The risk of SEN increased across the whole range of gestation from 40 to 24 wk: 37–39 wk adjusted odds ratio (OR) 1.16, 95% confidence interval (CI) 1.12–1.20; 33–36 wk adjusted OR 1.53, 95% CI 1.43–1.63; 28–32 wk adjusted OR 2.66, 95% CI 2.38–2.97; 24–27 wk adjusted OR 6.92, 95% CI 5.58–8.58. There was no interaction between elective versus spontaneous delivery. Overall, gestation at delivery accounted for 10% of the adjusted population attributable fraction of SEN. Because of their high frequency, early term deliveries (37–39 wk) accounted for 5.5% of cases of SEN compared with preterm deliveries (<37 wk), which accounted for only 3.6% of cases. <STRONG>Conclusions</STRONG> Gestation at delivery had a strong, dose-dependent relationship with SEN that was apparent across the whole range of gestation. Because early term delivery is more common than preterm delivery, the former accounts for a higher percentage of SEN cases. Our findings have important implications for clinical practice in relation to the timing of elective delivery

A formally verified compiler back-end

This article describes the development and formal verification (proof of semantic preservation) of a compiler back-end from Cminor (a simple imperative intermediate language) to PowerPC assembly code, using the Coq proof assistant both for programming the compiler and for proving its correctness. Such a verified compiler is useful in the context of formal methods applied to the certification of critical software: the verification of the compiler guarantees that the safety properties proved on the source code hold for the executable compiled code as well

Toward a simulation approach for alkene ring-closing metathesis : scope and limitations of a model for RCM

A published model for revealing solvent effects on the ring-closing metathesis (RCM) reaction of di-Et diallylmalonate 7 has been evaluated over a wider range of conditions, to assess its suitability for new applications. Unfortunately, the model is too flexible and the published rate consts. do not agree with exptl. studies in the literature. However, by fixing the values of important rate consts. and restricting the concn. ranges studied, useful conclusions can be drawn about the relative rates of RCM of different substrates, precatalyst concn. can be simulated accurately and the effect of precatalyst loading can be anticipated. Progress has also been made toward applying the model to precatalyst evaluation, but further modifications to the model are necessary to achieve much broader aims

Size of third and fourth ventricle in obstructive and communicating acute hydrocephalus after aneurysmal subarachnoid hemorrhage

In patients with acute hydrocephalus after aneurysmal subarachnoid haemorrhage (SAH), lumbar drainage is possible if the obstruction is in the subarachnoid space (communicating hydrocephalus). In case of intraventricular obstruction (obstructive hydrocephalus), ventricular drainage is the only option. A small fourth ventricle is often considered a sign of obstructive hydrocephalus. We investigated whether the absolute or relative size of the fourth ventricle can indeed distinguish between these two types of hydrocephalus. On CT-scans of 76 consecutive patients with acute headache but normal CT and CSF, we measured the cross-sectional surface of the third and fourth ventricle to obtain normal planimetric values. Subsequently we performed the same measurements on 117 consecutive SAH patients with acute hydrocephalus. These patients were divided according to the distribution of blood on CT-scan into three groups: mainly intraventricular blood (n = 15), mainly subarachnoid blood (n = 54) and both intraventricular and subarachnoid blood (n = 48). The size of the fourth ventricle exceeded the upper limit of normal in 2 of the 6 (33%) patients with intraventricular blood but without haematocephalus, and in 15 of the 54 (28%) patients with mainly subarachnoid blood. The mean ratio between the third and fourth ventricle was 1.45 (SD 0.66) in patients with intraventricular blood and 1.42 (SD 0.91) in those with mainly subarachnoid blood. Neither fourth ventricular size nor the ratio between the third and fourth ventricles discriminates between the two groups. A small fourth ventricle does not necessarily accompany obstructive hydrocephalus and is therefore not a contraindication for lumbar drainage

Do Bans on Affirmative Action Hurt Minority Students? Evidence from the Texas Top 10% Plan

Standard-Nutzungsbedingungen: Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch gespeichert und kopiert werden. Sie dürfen die Dokumente nicht für öffentliche oder kommerzielle Zwecke vervielfältigen, öffentlich ausstellen, öffentlich zugänglich machen, vertreiben oder anderweitig nutzen. Sofern die Verfasser die Dokumente unter Open-Content-Lizenzen (insbesondere CC-Lizenzen) zur Verfügung gestellt haben sollten, gelten abweichend von diesen Nutzungsbedingungen die in der dort genannten Lizenz gewährten Nutzungsrechte. www.econstor.eu The Institute for the Study of Labor (IZA) in Bonn is a local and virtual international research center and a place of communication between science, politics and business. IZA is an independent nonprofit organization supported by Deutsche Post Foundation. The center is associated with the University of Bonn and offers a stimulating research environment through its international network, workshops and conferences, data service, project support, research visits and doctoral program. IZA engages in (i) original and internationally competitive research in all fields of labor economics, (ii) development of policy concepts, and (iii) dissemination of research results and concepts to the interested public. Terms of use: Documents in D I S C U S S I O N P A P E R S E R I E S IZA Discussion Papers often represent preliminary work and are circulated to encourage discussion. Citation of such a paper should account for its provisional character. A revised version may be available directly from the author. In light of the recent bans on affirmative action in higher education, this paper provides new evidence on the effects of alternative admissions policies on the persistence and college completion of minority students. I find that the change from affirmative action to the Top 10% Plan in Texas decreased both retention and graduation rates of lower-ranked minority students. Results show that both fall-to-fall freshmen retention and six-year college graduation of second-decile minority students decreased, respectively, by 2.4 and 3.3 percentage points. The effect of the change in admissions policy was slightly larger for minority students in the third and lower deciles: fall-to-fall freshmen retention and six-year college graduation decreased, respectively, by 4.9 and 4.2 percentage points. Moreover, I find no evidence in support of the minority "mismatch" hypothesis. These results suggest that most of the increase in the graduation gap between minorities and non-minorities in Texas, a staggering 90 percent, was driven by the elimination of affirmative action in the 1990s. JEL Classification: I21, I23, J15, J2