246 research outputs found
Motivation, Mindset, and Grading Systems
This action research study examines whether students in a standards-based grading environment are more intrinsically motivated than students in traditional grading environment. Additionally, it examines whether students in a standards-based grading environment exhibit more of a fixed or growth mindset compared to students in a traditional grading environment. The participants were 72 sixth grade students in a standards-based grading classroom environment, and 32 students in a traditional grading-based classroom environment. A survey with statements reflecting students’ intrinsic motivation, extrinsic motivation, fixed mindset, and growth mindset was administered to both groups of students. The survey results suggest that the grading environment, standards-based or traditional, does not account for students’ levels of intrinsic and extrinsic motivation, nor does it predict whether a student has a fixed or growth mindset
A study of hypertension in twins
A study of the blood pressure of 86 pairs of like-sexed twins over age 40 selected at random was performed. Twelve per cent were found to have a diastolic blood pressure in excess of 94 mm. Hg. In 4 out of 5 identical twin sets both members were found to have hypertension of about equal magnitude. In the fifth set, the predetermined definition of diastolic hypertension was not met in one member of the pair, although the systolic blood pressure was clearly elevated. In two identical twin sets, where information concerning previous blood pressure could be obtained, the age of onset of the hypertension differed. Among the 49 dizygetic twin sets, diastolic hypertension was found in 15 per cent of the individuals. In 3 of 12 of these pairs, it was present in both members.Since the prevalence of hypertension after age 40 in the identical twin sample resembles that in the population at large, it is concluded that the ultimate development of this condition is heavily dependent on genetic influences.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/32777/1/0000150.pd
Interplay of initial deformation and Coulomb proximity on nuclear decay
Alpha particles emitted from an excited projectile-like fragment (PLF*)
formed in a peripheral collision of two intermediate-energy heavy ions exhibit
a strong preference for emission towards the target-like fragment (TLF). The
interplay of the initial deformation of the PLF* caused by the reaction,
Coulomb proximity, and the rotation of the PLF* results in the observed
anisotropic angular distribution. Changes in the shape of the angular
distribution with excitation energy are interpreted as being the result of
forming more elongated initial geometries in the more peripheral collisions.Comment: 4 figure
Excitation and decay of projectile-like fragments formed in dissipative peripheral collisions at intermediate energies
Projectile-like fragments (PLF:15<=Z<=46) formed in peripheral and
mid-peripheral collisions of 114Cd projectiles with 92Mo nuclei at E/A=50 MeV
have been detected at very forward angles, 2.1 deg.<=theta_lab<=4.2 deg.
Calorimetric analysis of the charged particles observed in coincidence with the
PLF reveals that the excitation of the primary PLF is strongly related to its
velocity damping. Furthermore, for a given V_PLF*, its excitation is not
related to its size, Z_PLF*. For the largest velocity damping, the excitation
energy attained is large, approximately commensurate with a system at the
limiting temperatureComment: 5 pages, 6 figure
Fragment Production in Non-central Collisions of Intermediate Energy Heavy Ions
The defining characteristics of fragment emission resulting from the
non-central collision of 114Cd ions with 92Mo target nuclei at E/A = 50 MeV are
presented. Charge correlations and average relative velocities for mid-velocity
fragment emission exhibit significant differences when compared to standard
statistical decay. These differences associated with similar velocity
dissipation are indicative of the influence of the entrance channel dynamics on
the fragment production process
Fragment Isospin as a Probe of Heavy-Ion Collisions
Isotope ratios of fragments produced at mid-rapidity in peripheral and
central collisions of 114Cd ions with 92Mo and 98Mo target nuclei at E/A = 50
MeV are compared. Neutron-rich isotopes are preferentially produced in central
collisions as compared to peripheral collisions. The influence of the size (A),
density, N/Z, E*/A, and Eflow/A of the emitting source on the measured isotope
ratios was explored by comparison with a statistical model (SMM). The
mid-rapidity region associated with peripheral collisions does not appear to be
neutron-enriched relative to central collisions.Comment: 12 pages including figure
Rapidity and centrality dependence of proton and antiproton production from 197Au + 197Au collisions at √SNN = 130 GeV
We report on the rapidity and centrality dependence of proton and antiproton transverse mass distributions from 197Au + 197Au collisions at sqrt[sNN ]=130 GeV as measured by the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). Our results are from the rapidity and transverse momentum range of |y| <0.5 and 0.35< pt <1.00 GeV/c . For both protons and antiprotons, transverse mass distributions become more convex from peripheral to central collisions demonstrating characteristics of collective expansion. The measured rapidity distributions and the mean transverse momenta versus rapidity are flat within |y| <0.5 . Comparisons of our data with results from model calculations indicate that in order to obtain a consistent picture of the proton (antiproton) yields and transverse mass distributions the possibility of prehadronic collective expansion may have to be taken into account
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