103 research outputs found

    The Long-Run Impacts of Same-Race Teachers

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    Black primary-school students matched to a same-race teacher perform better on standardized tests and face more favorable teacher perceptions, yet little is known about the long-run, sustained impacts of student-teacher demographic match. We show that assigning a black male to a black teacher in the third, fourth, or fifth grades significantly reduces the probability that he drops out of high school, particularly among the most economically disadvantaged black males. Exposure to at least one black teacher in grades 3-5 also increases the likelihood that persistently low-income students of both sexes aspire to attend a four-year college. These findings are robust across administrative data from two states and multiple identification strategies, including an instrumental variables strategy that exploits within-school, intertemporal variation in the proportion of black teachers, family fixed-effects models that compare siblings who attended the same school, and the random assignment of students and teachers to classrooms created by the Project STAR class-size reduction experiment

    Bichromatic Driving of a Solid State Cavity QED System

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    The bichromatic driving of a solid state cavity quantum electrodynamics system is used to probe cavity dressed state transitions and observe coherent interaction between the system and the light field. We theoretically demonstrate the higher order cavity-dressed states, supersplitting, and AC stark shift in a solid state system comprised of a quantum dot strongly coupled to a photonic crystal cavity for on- and far off-resonant cases. For the off-resonant case, phonons mediate off-resonant coupling between the quantum dot and the photonic resonator, a phenomenon unique to solid state cavity quantum electrodynamics.Comment: 8 pages 6 figure

    Receptor tyrosine kinase activation of RhoA is mediated by AKT phosphorylation of DLC1

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    We report several receptor tyrosine kinase (RTK) ligands increase RhoA-guanosine triphosphate (GTP) in untransformed and transformed cell lines and determine this phenomenon depends on the RTKs activating the AKT serine/threonine kinase. The increased RhoA-GTP results from AKT phosphorylating three serines (S298, S329, and S567) in the DLC1 tumor suppressor, a Rho GTPase-activating protein (RhoGAP) associated with focal adhesions. Phosphorylation of the serines, located N-terminal to the DLC1 RhoGAP domain, induces strong binding of that N-terminal region to the RhoGAP domain, converting DLC1 from an open, active dimer to a closed, inactive monomer. That binding, which interferes with the interaction of RhoA-GTP with the RhoGAP domain, reduces the hydrolysis of RhoA-GTP, the binding of other DLC1 ligands, and the colocalization of DLC1 with focal adhesions and attenuates tumor suppressor activity. DLC1 is a critical AKT target in DLC1-positive cancer because AKT inhibition has potent antitumor activity in the DLC1-positive transgenic cancer model and in a DLC1-positive cancer cell line but not in an isogenic DLC1-negative cell line

    Demonstration of Universal Parametric Entangling Gates on a Multi-Qubit Lattice

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    We show that parametric coupling techniques can be used to generate selective entangling interactions for multi-qubit processors. By inducing coherent population exchange between adjacent qubits under frequency modulation, we implement a universal gateset for a linear array of four superconducting qubits. An average process fidelity of F=93%\mathcal{F}=93\% is estimated for three two-qubit gates via quantum process tomography. We establish the suitability of these techniques for computation by preparing a four-qubit maximally entangled state and comparing the estimated state fidelity against the expected performance of the individual entangling gates. In addition, we prepare an eight-qubit register in all possible bitstring permutations and monitor the fidelity of a two-qubit gate across one pair of these qubits. Across all such permutations, an average fidelity of F=91.6±2.6%\mathcal{F}=91.6\pm2.6\% is observed. These results thus offer a path to a scalable architecture with high selectivity and low crosstalk

    Venous thromboembolism after inpatient surgery in administrative data vs NSQIP: a multi-institutional study

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    Previous studies have documented significant differences between administrative data and registry data in the determination of postoperative venous thromboembolism (VTE). The goal of this study was to characterize the discordance between administrative and registry data in the determination of postoperative VTE.This study was performed using data from the American College of Surgeons NSQIP merged with administrative data from 8 different hospitals (5 different medical centers) between 2013 and 2015. Occurrences of postoperative vein thrombosis (VT) and pulmonary embolism (PE) as ascertained by administrative data and NSQIP data were compared. In each situation where the 2 sources disagreed (discordance), a 2-clinician chart review was performed to characterize the reasons for discordance.The cohort used for analysis included 43,336 patients, of which 53.3% were female and the mean age was 59.5 years. Concordance between administrative and NSQIP data was worse for VT (Îş 0.57; 95% CI 0.51 to 0.62) than for PE (Îş 0.83; 95% CI 0.78 to 0.89). A total of 136 cases of discordance were noted in the assessment of VT; of these, 50 (37%) were explained by differences in the criteria used by administrative vs NSQIP systems. In the assessment of postoperative PE, administrative data had a higher accuracy than NSQIP data (odds ratio for accuracy 2.86; 95% CI 1.11 to 7.14) when compared with the 2-clinician chart review.This study identifies significant problems in ability of both NSQIP and administrative data to assess postoperative VT/PE. Administrative data functioned more accurately than NSQIP data in the identification of postoperative PE. The mechanisms used to translate VTE measurement into quality improvement should be standardized and improved

    Gain-of-function RHOA mutations promote focal adhesion kinase activation and dependency in diffuse gastric cancer

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    Diffuse gastric cancer (DGC) is a lethal malignancy lacking effective systemic therapy. Among the most provocative recent results in DGC has been that of highly recurrent missense mutations in the GTPase RHOA. The function of these mutations has remained unresolved. We demonstrate that RHOAY42C, the most common RHOA mutation in DGC, is a gain-of-function oncogenic mutant, and that expression of RHOAY42C with inactivation of the canonical tumor suppressor Cdh1 induces metastatic DGC in a mouse model. Biochemically, RHOAY42C exhibits impaired Y42C GTP hydrolysis and enhances interaction with its effector ROCK. RHOA mutation and Cdh1 loss induce actin/cytoskeletal rearrangements and activity of focal adhesion kinase (FAK), which activates YAP–TAZ, PI3K–AKT, and β-catenin. RHOAY42C murine models were sensitive to FAK inhibition and to combined YAP and PI3K pathway blockade. These results, coupled with sensitivity to FAK inhibition in patient-derived DGC cell lines, nominate FAK as a novel target for these cancers. SIGNIFICANCE: The functional significance of recurrent RHOA mutations in DGC has remained unresolved. Through biochemical studies and mouse modeling of the hotspot RHOAY42C mutation, we establish that these mutations are activating, detail their effects upon cell signaling, and define how RHOA-mediated FAK activation imparts sensitivity to pharmacologic FAK inhibitors

    Genes, Education, and Labor Market Outcomes: Evidence from the Health and Retirement Study

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    Recent advances have led to the discovery of specific genetic variants that predict educational attainment. We study how these variants, summarized as a genetic score variable, are associated with human capital accumulation and labor market outcomes in the Health and Retirement Study (HRS). We demonstrate that the same genetic score that predicts education is also associated with higher wages, but only among individuals with a college education. Moreover, the genetic gradient in wages has grown in more recent birth cohorts, consistent with interactions between technological change and labor market ability. We also show that individuals who grew up in economically disadvantaged households are less likely to go to college when compared to individuals with the same genetic score, but from higher socioeconomic status households. Our findings provide support for the idea that childhood socioeconomic status is an important moderator of the economic returns to genetic endowments. Moreover, the finding that childhood poverty limits the educational attainment of high-ability individuals suggests the existence of unrealized human potential

    Who Believes in Me? The Effect of Student-Teacher Demographic Match on Teacher Expectations

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    Teachers are an important source of information for traditionally disadvantaged students. However, little is known about how teachers form expectations and whether they are systematically biased. We investigate whether student-teacher demographic mismatch affects high school teachers’ expectations for students’ educational attainment. Using a student fixed effects strategy that exploits expectations data from two teachers per student, we find that non-black teachers of black students have significantly lower expectations than do black teachers. These effects are larger for black male students and math teachers. Our findings add to a growing literature on the role of limited information in perpetuating educational attainment gaps
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