120 research outputs found
Service Learning in Overseas Nations: U.S. Student Teachers Give, Grow, and Gain Outside the Classroom
Service learning and overseas student teaching are receiving increased attention in education literature. For example, Kielsmeier (1993) touts service learning as an emerging educational improvement strategy (p. 5) in the U.S. school reform movement. Learning activities, by combining classroom work with service/social action projects, ... can help produce dramatic improvements in student attitudes, motivation, and achievement (Nathan & Kielsmeier, 1991, p. 739)
Cross-Cultural Field Placements: Student Teachers Learning From Schools and Communities
The student teaching experience is typically characterized by a collaboration of school and university-cooperating teacher and university supervisor- to prepare novice educators for the instructional, managerial, and disciplinary demands of classroom teaching. Less often are individuals and groups outside of the immediate school environment perceived as active and important contributors to learning outcomes and professional development for student teachers. However, an increasing number of teacher educators are addressing the role of the community in providing student teachers with information and insights that will enhance the classroom experience in vital ways
Service Learning in Overseas and Navajo Reservation Communities: Student Teachersâ Powerful Experiences Build Community Connections, Broaden Worldview, and Inform Classroom Practice
A study examined student teachers\u27 service learning in Navajo Reservation and overseas communities. Participants were 88 student teachers attending Indiana University. Results revealed that student teachers\u27 service learning experiences helped to build community links, contributed to broader worldviews, and informed classroom practice
Exploring Student and Faculty Reactions to Smartphone Policies in the Classroom
The current studies examined attitudes about classroom cell phone usage and reactions to cell phone policies among students and faculty. Study 1 documented studentsâ and facultyâs perceptions of appropriateness of cell phones in the classroom and about what classroom policies should be. Students reported greater leniency regarding cell phone use in the classroom and suggested stricter penalties for inappropriate use. Study 2 surveyed faculty and students about four cell phone policies ranging in level of leniency. The results indicated as policy leniency increased, cell phone use increased and enforcement decreased. Study 3 evaluated studentsâ reactions to actual classroom cell phone policies. Students reported using their phones more than they anticipated and rated policy enforcement lower than expected, except under a prohibitive policy. These results indicate that differences remain between faculty and students and that there is a mismatch between what students prefer and perceive as effective cell phone policies
Signatures of the disk-jet coupling in the Broad-line Radio Quasar 4C+74.26
Here we explore the disk-jet connection in the broad-line radio quasar
4C+74.26, utilizing the results of the multiwavelength monitoring of the
source. The target is unique in that its radiative output at radio wavelengths
is dominated by a moderately-beamed nuclear jet, at optical frequencies by the
accretion disk, and in the hard X-ray range by the disk corona. Our analysis
reveals a correlation (local and global significance of 96\% and 98\%,
respectively) between the optical and radio bands, with the disk lagging behind
the jet by days. We discuss the possible explanation for this,
speculating that the observed disk and the jet flux changes are generated by
magnetic fluctuations originating within the innermost parts of a truncated
disk, and that the lag is related to a delayed radiative response of the disk
when compared with the propagation timescale of magnetic perturbations along
relativistic outflow. This scenario is supported by the re-analysis of the
NuSTAR data, modelled in terms of a relativistic reflection from the disk
illuminated by the coronal emission, which returns the inner disk radius
. We discuss the global energetics in
the system, arguing that while the accretion proceeds at the Eddington rate,
with the accretion-related bolometric luminosity erg s , the jet total kinetic energy
erg s, inferred from the dynamical
modelling of the giant radio lobes in the source, constitutes only a small
fraction of the available accretion power.Comment: 9 pages and 6 figures, ApJ accepte
Radial Velocity Studies of Close Binary Stars. IX
Radial-velocity measurements and sine-curve fits to the orbital velocity
variations are presented for the eighth set of ten close binary systems: AB
And, V402 Aur, V445 Cep, V2082 Cyg, BX Dra, V918 Her, V502 Oph, V1363 Ori, KP
Peg, V335 Peg. Half of the systems (V445 Cep, V2082 Cyg, V918 Her, V1363 Ori,
V335 Peg) were discovered photometrically by the Hipparcos mission and all
systems are double-lined (SB2) contact binaries. The broadening function method
permitted improvement of the orbital elements for AB And and V502 Oph. The
other systems have been observed for radial velocity variations for the first
time; in this group are five bright (V<7.5) binaries: V445 Cep, V2082 Cyg, V918
Her, KP Peg and V335 Peg. Several of the studied systems are prime candidates
for combined light and radial-velocity synthesis solutions.Comment: 17+ pages, 2 tables, 4 figure
Radial Velocity Studies of Close Binary Stars.VI
Radial-velocity measurements and sine-curve fits to the orbital velocity
variations are presented for the sixth set of ten close binary systems: SV Cam,
EE Cet, KR Com, V410 Cyg, GM Dra, V972 Her, ET Leo, FS Leo, V2388 Oph, II UMa.
All systems except FS Leo are double-lined spectroscopic binaries. The type of
FS Leo is unknown while SV Cam is a close, detached binary; all remaining
systems are contact binaries. Eight binaries (all except SV Cam and V401 Cyg)
are the recent photometric discoveries of the Hipparcos satellite project. Five
systems, EE Cet, KR Com, V401 Cyg, V2388 Oph, II UMa, are members of
visual/spectroscopic triple systems. We were able to observe the close binary
system EE Cet separately of its companion, but in the remaining four systems we
could separate the spectral components only through the use of the
broadening-function approach. Several of the studied systems are prime
candidates for combined light and radial-velocity synthesis solutions.Comment: AASTeX5, 5 figures, 2 tables, modified after the AJ revie
Observations of the pulsating subdwarf B star Feige 48: Constraints on evolution and companions
Since pulsating subdwarf B (sdBV or EC14026) stars were first discovered
(Kilkenny et al, 1997), observational efforts have tried to realize their
potential for constraining the interior physics of extreme horizontal branch
(EHB) stars. Difficulties encountered along the way include uncertain mode
identifications and a lack of stable pulsation mode properties. Here we report
on Feige 48, an sdBV star for which follow-up observations have been obtained
spanning more than four years, which shows some stable pulsation modes.
We resolve the temporal spectrum into five stable pulsation periods in the
range 340 to 380 seconds with amplitudes less than 1%, and two additional
periods that appear in one dataset each. The three largest amplitude
periodicities are nearly equally spaced, and we explore the consequences of
identifying them as a rotationally split l=1 triplet by consulting with a
representative stellar model.
The general stability of the pulsation amplitudes and phases allows us to use
the pulsation phases to constrain the timescale of evolution for this sdBV
star. Additionally, we are able to place interesting limits on any stellar or
planetary companion to Feige 48.Comment: accepted for publication in MNRA
Immunotoxicity of polystyrene nanoplastics in different hemocyte subpopulations of Mytilus galloprovincialis
Plastic represents 60-80% of litter in the ocean. Degradation of plastic to small fragments leads to the formation of microplastics (MPs <5mm) and nanoplastics (NPs <1 mu m). One of the most widely used and representative plastics found in the ocean is polystyrene (PS). Among marine organisms, the immune system of bivalves is recognized as suitable to assess nanomaterial toxicity. Hemocyte subpopulations [R1 (large granular cells), R2 (small semi-granular cells) and R3 (small agranular or hyaline cells)] of Mytilus galloprovincialis are specialized in particular tasks and functions. The authors propose to examine the effects of different sizes (50 nm, 100 nm and 1 mu m) PS NPs on the different immune cells of mussels when they were exposed to (1 and 10mg.L-1) of PS NPs. The most noteworthy results found in this work are: (i) 1 mu m PS NPs provoked higher immunological responses with respect to 50 and 100nm PS NPs, possibly related to the higher stability in size and shape in hemolymph serum, (ii) the R1 subpopulation was the most affected with respect to R2 and R3 concerning immunological responses and (iii) an increase in the release of toxic radicals, apoptotic signals, tracking of lysosomes and a decrease in phagocytic activity was found in R1
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