738 research outputs found
Science in the Middle School Revisited: Contrasting 1965 with 1990
Describing science as middle school students experience it continues to be a challenge. The science that students experience in the classroom is that which their teachers have selected and organized for them. This selection/organization process is itself guided by the teacher\u27s knowledge base and the expectations of the schooling context. Presented here is a contrast practiced in the middle school in 1990 with 1965. The findings show that while teachers today may be better prepared in terms of academic courses, they are still not being adequately prepared to work with the emerging adolescent in the middle school
The Business Case for the Efficiency and Effectiveness of Tele-Intensive Care Units
A tele-Intensive Care Unit (tele-ICU) is the use of telemedicine in an Intensive Care Unit (ICU) setting, using technology to provide care to critically ill patients by off-site clinical resources. This literature review examined a large number of studies of the implementation of tele-ICU systems in hospitals. Generally, implementation of a tele-ICU system was associated with cost savings, shorter lengths of stay, and decreased mortality. Implementation of tele-ICUs is initially relatively expensive but result in cost savings and better clinical outcomes. Intensivists working these systems are used more effective providing better clinical outcomes for patients at lower costs for hospitals
Comparison of DMSP cross-track ion drifts and SuperDARN line-of-sight velocities
Cross-track ion drifts measured by the DMSP satellites are compared with line-of-sight SuperDARN HF velocities in approximately the same directions. Good overall agreement is found for a data set comprising of 209 satellite passes over the field of view of nine SuperDARN radars in both the Northern and Southern Hemispheres. The slope of the best linear fit line relating the SuperDARN and DMSP velocities is of the order of 0.7 with a tendency for SuperDARN velocities to be smaller. The agreement implies that the satellite and radar data can be merged into a common set provided that spatial and temporal variations of the velocity as measured by both instruments are smooth.<br><br> <b>Keywords.</b> Ionosphere (Ionospheric irregularities; Plasma convection; Auroral ionosphere
An Inservice Model to Impact Life Science Classroom Practice: Part One
A model inservice program built on a theoretical foundation for changing behavior incorporates both teachers\u27 knowledge, their attitudes as well as what they do. What teachers do in the classroom depends on both what they know and how they feel about what they know, Changing what teachers know and do is accomplished in a three phase sequence, awareness, arousal and action. In the awareness phase, teachers are confronted with their knowledge needs. In the arousal phase, teacher generate interest in using what they know. Action is reflected in what teachers do and is reinforced when they have time to reflect on that action, its effect, its value and acceptance
An Inservice Model to Impact Life-Science Classroom Practice: Part Two
This model for an inservice program describes why teachers change the nature of their students\u27 experiences in science. In the evaluation study with 7th grade Life Science teachers in Southeast, evidence showed that as teachers\u27 knowledge in specific topics in biology was enhanced, their classroom use of this knowledge also changed. As their knowledge of science and alternative teaching practices was expanded, their attitudes toward teaching showed that they were more aware that there was more to learn but were also more confident that they could acquire the new knowledge they needed. In their classroom, their concerns for students showed significant shifts toward involving students more in their learning rather than being most concerned about managing or controlling them. This was especially true if there was an institutional willingness for them to use different teaching strategies. Thus based on this evaluation study, teachers are more likely to change if the changes are consistent with the external demands of their schooling context; and their internal belief systems
Magnetospheric Response Times Following Southward IMF Turnings
We analyze the response times of various regions of the magnetosphere-ionosphere system to sudden southward turnings of the IMF. Our data set consists of 26 events during which the IMP BZ component was observed by WIND to change from a stea northward field to a southward field, which subsequently led to a substorm. The magnetospheric response to such IMF southward turnings is examined using data from the POLAR EFI experiment, the GOES 9 magnetometer, and ground magnetometers. The POLAR/EFI was used to investigate changes in the polar cap electric field which occurred in response to the changing interplanetary electric field, and these results are compared with response timings derived from high-latitude ground magnetometers. POLAR/EFI data show responses in the polar cap about 15 minutes after the arrival of the IMF change at the magnetopause. Auroral zone magnetograms and geosynchronous spacecraft measurements are utilized to evaluate the response timing within the closed field line region. In one event examined in detail, the start of a substorm growth phase was observed by GOES 9 in the midnight sector of geosynchronous orbit about two minutes before POLAR observed a response in the polar cap. Using superposed epoch analysis, we calculate typical response times in the polar cap, in the nightside plasma sheet, and in the ionosphere in order to discuss the various suggested mechanisms for information propagation from the subsolar magnetopause into the magnetosphere. We find that for the set of ten events for which the GOES 9 and the CANOPUS array are in the midnight sector, the field at geosynchronous as measured by GOES responds at or before the time of response in the polar cap as measured by POLAR, suggesting different methods of information propagation
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Youll feel better in the morning: slow wave activity and overnight mood regulation in interepisode bipolar disorder.
BACKGROUND: Sleep disturbances are prominent correlates of acute mood episodes and inadequate recovery in bipolar disorder (BD), yet the mechanistic relationship between sleep physiology and mood remains poorly understood. Using a series of pre-sleep mood inductions and overnight sleep recording, this study examined the relationship between overnight mood regulation and a marker of sleep intensity (non-rapid eye movement sleep slow wave activity; NREM SWA) during the interepisode phase of BD. METHODS: Adults with interepisode BD type 1 (BD; n = 20) and healthy adult controls (CTL; n = 23) slept in the laboratory for a screening night, a neutral mood induction night (baseline), a happy mood induction night, and a sad mood induction night. NREM SWA (0.75-4.75 Hz) was derived from overnight sleep EEG recordings. Overnight mood regulation was evaluated using an affect grid pleasantness rating post-mood induction (pre-sleep) and the next morning. RESULTS: Overnight mood regulation did not differ between groups following the sad or happy inductions. SWA did not significantly change for either group on the sad induction night compared with baseline. In BD only, SWA on the sad night was related to impaired overnight negative mood regulation. On the happy induction night, SWA increased relative to baseline in both groups, though SWA was not related to overnight mood regulation for either group. CONCLUSIONS: These findings indicate that SWA disruption may play a role in sustaining negative mood state from the previous night in interepisode BD. However, positive mood state could enhance SWA in bipolar patients and healthy adults
Effects of rapid prey evolution on predator-prey cycles
We study the qualitative properties of population cycles in a predator-prey
system where genetic variability allows contemporary rapid evolution of the
prey. Previous numerical studies have found that prey evolution in response to
changing predation risk can have major quantitative and qualitative effects on
predator-prey cycles, including: (i) large increases in cycle period, (ii)
changes in phase relations (so that predator and prey are cycling exactly out
of phase, rather than the classical quarter-period phase lag), and (iii)
"cryptic" cycles in which total prey density remains nearly constant while
predator density and prey traits cycle. Here we focus on a chemostat model
motivated by our experimental system [Fussmann et al. 2000,Yoshida et al. 2003]
with algae (prey) and rotifers (predators), in which the prey exhibit rapid
evolution in their level of defense against predation. We show that the effects
of rapid prey evolution are robust and general, and furthermore that they occur
in a specific but biologically relevant region of parameter space: when traits
that greatly reduce predation risk are relatively cheap (in terms of reductions
in other fitness components), when there is coexistence between the two prey
types and the predator, and when the interaction between predators and
undefended prey alone would produce cycles. Because defense has been shown to
be inexpensive, even cost-free, in a number of systems [Andersson and Levin
1999, Gagneux et al. 2006,Yoshida et al. 2004], our discoveries may well be
reproduced in other model systems, and in nature. Finally, some of our key
results are extended to a general model in which functional forms for the
predation rate and prey birth rate are not specified.Comment: 35 pages, 8 figure
Rapid contemporary evolution and clonal food web dynamics
Character evolution that affects ecological community interactions often
occurs contemporaneously with temporal changes in population size, potentially
altering the very nature of those dynamics. Such eco-evolutionary processes may
be most readily explored in systems with short generations and simple genetics.
Asexual and cyclically parthenogenetic organisms such as microalgae,
cladocerans, and rotifers, which frequently dominate freshwater plankton
communities, meet these requirements. Multiple clonal lines can coexist within
each species over extended periods, until either fixation occurs or a sexual
phase reshuffles the genetic material. When clones differ in traits affecting
interspecific interactions, within-species clonal dynamics can have major
effects on the population dynamics. We first consider a simple predator-prey
system with two prey genotypes, parameterized with data on a well-studied
experimental system, and explore how the extent of differences in defense
against predation within the prey population determine dynamic stability versus
instability of the system. We then explore how increased potential for
evolution affects the community dynamics in a more general community model with
multiple predator and multiple prey genotypes. These examples illustrate how
microevolutionary "details" that enhance or limit the potential for heritable
phenotypic change can have significant effects on contemporaneous
community-level dynamics and the persistence and coexistence of species.Comment: 30 pages, 6 Figure
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