99 research outputs found
Effects of early intervention targeting mathematically at-risk first grade students [abstract]
Abstract only availableIn the 2006-2007 school year, 7.3 percent of third grade students scored in the lowest percentile in mathematics on the Missouri Assessment Program test. This percentage increased as students progressed through school. In tenth grade, 24 percent of students scored below average. Although it is troubling that 7.3 percent of students were already struggling in third grade, this data shows more students are falling behind in mathematics as they progress through the grades. These percentages stress the importance of reaching students during early grades because a sound base in mathematics will keep students at grade-level throughout their schooling. Our study targets two first grade students who have been identified as mathematically at-risk by their teachers. One is a Caucasian male while the other is an African American female. The project examines whether or not individualized tutoring sessions based on an intervention program can increase the students' procedural and conceptual understanding in mathematics. Initial assessments measuring the students' understanding of mathematical concepts were administered. The research team met with students biweekly for tutoring sessions that targeted the skills they struggled with on the assessments. Students' progress was monitored throughout the year and the research team adjusted the students' activities based on each student's strengths and areas of concern. In May, students will be reassessed using the initial assessment. Results from the two time points will be compared and analyzed to ascertain how the students' performance has changed. The study will focus on students' performance in all of these areas with the assumption that the intervention program will have a positive influence. If significant improvement does not emerge, a reevaluation of the tasks and a consideration of what other factors might have affected student performance will be undertaken. Early intervention programs, such as this one, are an important step in helping mathematically at-risk students perform at grade level
Association of pre-radiotherapy tumour burden and overall survival in newly diagnosed glioblastoma adjusted for MGMT promoter methylation status
PURPOSE: We retrospectively evaluated the association between postoperative pre-radiotherapy tumour burden and overall survival (OS) adjusted for the prognostic value of O-methylguanine DNA methyltransferase (MGMT) promoter methylation in patients with newly diagnosed glioblastoma treated with radio-/chemotherapy with temozolomide.
MATERIALS AND METHODS: Patients were included from the CENTRIC (EORTC 26071-22072) and CORE trials if postoperative magnetic resonance imaging scans were available within a timeframe of up to 4weeks before radiotherapy, including both pre- and post-contrast T1w images and at least one T2w sequence (T2w or T2w-FLAIR). Postoperative (residual) pre-radiotherapy contrast-enhanced tumour (CET) volumes and non-enhanced T2w abnormalities (NT2A) tissue volumes were obtained by three-dimensional segmentation. Cox proportional hazard models and Kaplan Meier estimates were used to assess the association of pre-radiotherapy CET/NT2A volume with OS adjusted for known prognostic factors (age, performance status, MGMT status).
RESULTS: 408 tumour (of which 270 MGMT methylated) segmentations were included. Median OS in patients with MGMT methylated tumours was 117 weeks versus 61weeks in MGMT unmethylated tumours (p < 0.001). When stratified for MGMT methylation status, higher CET volume (HR 1.020; 95% confidence interval CI [1.013-1.027]; p < 0.001) and older age (HR 1.664; 95% CI [1.214-2.281]; p = 0.002) were significantly associated with shorter OS while NT2A volume and performance status were not.
CONCLUSION: Pre-radiotherapy CET volume was strongly associated with OS in patients receiving radio-/chemotherapy for newly diagnosed glioblastoma stratified by MGMT promoter methylation status
Association of pre-radiotherapy tumour burden and overall survival in newly diagnosed glioblastoma adjusted for <i>MGMT </i>promoter methylation status
PURPOSE: We retrospectively evaluated the association between postoperative pre-radiotherapy tumour burden and overall survival (OS) adjusted for the prognostic value of O-methylguanine DNA methyltransferase (MGMT) promoter methylation in patients with newly diagnosed glioblastoma treated with radio-/chemotherapy with temozolomide.
MATERIALS AND METHODS: Patients were included from the CENTRIC (EORTC 26071-22072) and CORE trials if postoperative magnetic resonance imaging scans were available within a timeframe of up to 4weeks before radiotherapy, including both pre- and post-contrast T1w images and at least one T2w sequence (T2w or T2w-FLAIR). Postoperative (residual) pre-radiotherapy contrast-enhanced tumour (CET) volumes and non-enhanced T2w abnormalities (NT2A) tissue volumes were obtained by three-dimensional segmentation. Cox proportional hazard models and Kaplan Meier estimates were used to assess the association of pre-radiotherapy CET/NT2A volume with OS adjusted for known prognostic factors (age, performance status, MGMT status).
RESULTS: 408 tumour (of which 270 MGMT methylated) segmentations were included. Median OS in patients with MGMT methylated tumours was 117 weeks versus 61weeks in MGMT unmethylated tumours (p < 0.001). When stratified for MGMT methylation status, higher CET volume (HR 1.020; 95% confidence interval CI [1.013-1.027]; p < 0.001) and older age (HR 1.664; 95% CI [1.214-2.281]; p = 0.002) were significantly associated with shorter OS while NT2A volume and performance status were not.
CONCLUSION: Pre-radiotherapy CET volume was strongly associated with OS in patients receiving radio-/chemotherapy for newly diagnosed glioblastoma stratified by MGMT promoter methylation status
Systematic investigation of the elastic proton-deuteron differential cross section at intermediate energies
To investigate the importance of three-nucleon forces (3NF) systematically
over a broad range of intermediate energies, the differential cross sections of
elastic proton-deuteron scattering have been measured at proton bombarding
energies of 108, 120, 135, 150, 170 and 190 MeV at center-of-mass angles
between and . Comparisons with Faddeev calculations show
unambiguously the shortcomings of calculations employing only two-body forces
and the necessity of including 3NF. They also show the limitations of the
latest few-nucleon calculations at backward angles, especially at higher beam
energies. Some of these discrepancies could be partially due to relativistic
effects. Data at lowest energy are also compared with a recent calculation
based on \chipt
Proton-deuteron radiative capture cross sections at intermediate energies
Differential cross sections of the reaction have been
measured at deuteron laboratory energies of 110, 133 and 180 MeV. The data were
obtained with a coincidence setup measuring both the outgoing He and the
photon. The data are compared with modern calculations including all possible
meson-exchange currents and two- and three- nucleon forces in the potential.
The data clearly show a preference for one of the models, although the shape of
the angular distribution cannot be reproduced by any of the presented models.Comment: 6 pages, 6 figures, accepted for publication in EPJ
Proton-proton bremsstrahlung towards the elastic limit at 190 MeV incident beam energy
AbstractA series of nucleonânucleon bremsstrahlung (NNÎł) experiments at 190 MeV incident beam energy have been performed at KVI in order to gain more insight into the dynamics governing the bremsstrahlung reaction. After initial measurements wherein the bremsstrahlung process was studied far away from the elastic limit, a new study was used to probe the process nearer to the elastic limit by measuring at lower photon energies. Measured cross sections and analyzing powers are compared with the predictions of a microscopic model and those of two soft-photon models. The theoretical calculations overestimate the data by up to â30%, for some kinematics
Wages in high-tech start-ups - do academic spin-offs pay a wage premium?
Due to their origin from universities, academic spinâoffs operate at the forefront of the
technological development. Therefore, spinâoffs exhibit a skillâbiased labour demand, i.e. spinâoffs
have a high demand for employees with cutting edge knowledge and technical skills. In order to accommodate
this demand, spinâoffs may have to pay a relative wage premium compared to other
highâtech startâups. However, neither a comprehensive theoretical assessment nor the empirical
literature on wages in startâups unambiguously predicts the existence and the direction of wage differentials
between spinâoffs and nonâspinâoffs. This paper addresses this research gap and examines
empirically whether or not spinâoffs pay their employees a wage premium. Using a unique linked
employerâemployee data set of German highâtech startâups, we estimate Mincerâtype wage regressions
applying the HausmanâTaylor panel estimator. Our results show that spinâoffs do not pay a
wage premium in general. However, a notable exception from this general result is that spinâoffs that
commercialise new scientific results or methods provide higher wages to employees with linkages to
the university sector â either as university graduates or as student workers
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