920 research outputs found
Simultaneous measurements of magnetotail dynamics by IMP spacecraft
Changes in tail energy density during substorms in the magnetotail are given. In addition to plasma sheet thinnings seen prior to substorm onsets, a gradual decrease in plasma beta was detected in the deep tail which precedes onset and the more prominent plasma disappearance that typically accompanies it. The frequency of thinnings and the regions over which they occurred indicate that drastic changes in plasma sheet thickness are common features of substorms which occur at all locations across the tail
Neurotransmitter interactions in the stomatogastric system of the spiny lobster: One peptide alters the response of a central pattern generator to a second peptide
Two of the peptides found in the stomatogastric nervous system of the spiny lobster. Panulirus interruptus, interacted to modulate the activity of the cardiac sac motor pattern. In the isolated stomatogastric ganglion, red- pigment-concentrating hormone (RPCH), but not proctolin, activated the bursting activity in the inferior ventricular (IV) neurons that drives the cardiac sac pattern. The cardiac sac pattern normally ceased within 15 min after the end of RPCH superfusion. However, when proctolin was applied within a few minutes of that time, it was likewise able to induce cardiac sac activity. Similarly, proctolin applied together with subthreshold RPCH induced cardiac sac bursting. The amplitude of the excitatory postsynaptic potentials from the IV neurons to the cardiac sac dilator neuron CD2 (1 of the 2 major motor neurons in the cardiac sac system) was potentiated in the presence of both proctolin and RPCH. The potentiation in RPCH was much greater than in proctolin alone. However, the potentiation in proctolin after RPCH was equivalent to that recorded in RPCH alone. Although we do not yet understand the mechanisms for these interactions of the two modulators, this study provides an example of one factor that can determine the \u27state\u27 of the system that is critical in determining the effect of a modulator that is \u27state dependent,\u27 and it provides evidence for yet another level of flexibility in the motor output of this system
One-Liners
One-Liners from P.T. Borgia, J. Irelan and E.U. Selker, and B.C. Turner and A. Fairfiel
Bostonia. Volume 12
Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs
MeV magnetosheath ions energized at the bow shock
A causal relationship between midlatitude magnetosheath energetic ions and bow shock magnetic geometry was previously established for ion energy up to 200 keV eâ1 for the May 4, 1998, storm event. This study demonstrates that magnetosheath ions with energies above 200 keV up to 1 MeV simply extend the ion spectrum to form a power law tail. Results of cross-correlation analysis suggest that these ions also come directly from the quasi-parallel bow shock, not the magnetosphere. This is confirmed by a comparison of energetic ion fluxes simultaneously measured in the magnetosheath and at the quasi-parallel bow shock when both regions are likely connected by the magnetic field lines. We suggest that ions are accelerated at the quasi-parallel bow shock to energies as high as 1 MeV and subsequently transported into the magnetosheath during this event
Improving Colorectal Cancer Screening Decision Making Processes
Introduction:
Although shared decision making is recommended for cancer screening, it is not routinely completed in practice because of time constraints. We evaluated a process for improving decision making about colorectal cancer (CRC) screening using mailed decision aids (DA) with follow-up telephone support in primary care practices.
Methods:
We identified patients aged 50-75 who were not up to date with CRC screening in three primary care practices. DA were distributed via mail with telephone follow-up to eligible patients, and charts were reviewed six months later for CRC screening completion.
Results:
Among 1,064 eligible patients who received the mailed DA, 513 (48.2%) were reached by phone. During the six months after the intervention, 148/1064 (13.9%) patients were screened for CRC (4.8% underwent FIT, 9.1% underwent colonoscopy). Younger patients (aged 50-54) had higher rates of any screening (32.4%) compared with all other age groups (range 12.8%-19.6%), p=0.026, while Medicaid patients had the lowest rates of screening (4.0%), and insured patients had the highest rates (45.3%), p=0.003. Overall, 113/513 (22.0%) who were reached by phone went on to complete screening within 6 months, compared with 35/551 (6.4%) of patients who were not reached by phone (p
Conclusion:
A standard process for identifying patients unscreened for CRC and DA distribution via mail with telephone decision support modestly increased CRC screening and is consistent with the goal of providing preference-sensitive care and informed decision making. Improving care processes to include decision support outside of office visits is possible in primary care practices
Pressure balance at the magnetopause: Experimental studies
The pressure balance at the magnetopause is formed by magnetic field and
plasma in the magnetosheath, on one side, and inside the magnetosphere, on the
other side. In the approach of dipole earth's magnetic field configuration and
gas-dynamics solar wind flowing around the magnetosphere, the pressure balance
predicts that the magnetopause distance R depends on solar wind dynamic
pressure Pd as a power low R ~ Pd^alpha, where the exponent alpha=-1/6. In the
real magnetosphere the magnetic filed is contributed by additional sources:
Chapman-Ferraro current system, field-aligned currents, tail current, and
storm-time ring current. Net contribution of those sources depends on
particular magnetospheric region and varies with solar wind conditions and
geomagnetic activity. As a result, the parameters of pressure balance,
including power index alpha, depend on both the local position at the
magnetopause and geomagnetic activity. In addition, the pressure balance can be
affected by a non-linear transfer of the solar wind energy to the
magnetosheath, especially for quasi-radial regime of the subsolar bow shock
formation proper for the interplanetary magnetic field vector aligned with the
solar wind plasma flow.Comment: 8 pages, 2 figure
Never Mind the Gap: Formative Assessment Confronted with Deweyâs and Gadamerâs Concept of Experience
The notion of âclosing the learning gapâ is widely used in the conceptualisation of formative assessment. It builds on an unarticulated assumption that students' learning can and should be controlled towards predefined outcomes. This article discusses this control assumption in the light of the concept of the American philosopher John Dewey and the German philosopher HansâGeorg Gadamer. Their conceptualisation challenges the idea of learning as a linear and controllable process that results in stable and predictable outcomes. Using the concept of experience, we argue that learning follows a continuous circular movement where previous experiences condition future interpretations and that every experience changes the subject. This process of change is both unpredictable and diverse and requires that attention is paid to the uniqueness of each situation and to students as subjects. Following the discussion, we propose a model for considering the extensiveness and rigidity of formative assessment practices and that authors pay attention to whether they conceptualise formative assessment in a way that promotes student and teacher âgap closingâ and control.publishedVersio
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