6,654 research outputs found
The GeoHistorian Project
The GeoHistorian Project is an initiative from Kent State University's Research Center for Educational Technology (RCET), aimed at educating K-12 students to become local historians who create digital content for an audience that transcends the walls of their classrooms. Project activities will include the creation of curriculum for teaching how to do digital, local history, training teachers how to apply it in their classrooms, and curriculum implementation. Expected outcomes include student-created, digital, and local historical content that will be available online and freely accessible by way of wireless mobile devices and QR codes (2-dimensional bar codes) that will be placed in relevant community locations. In addition, we will evaluate the impact of the GeoHistorian curriculum on student learning in the humanities and the role that digital technologies play in this process. Finally, we will investigate how our efforts can be scaled up and sustained over a longer period of time
Effect of local treatments of convection upon the solar p-mode excitation rates
We compute, for several solar models, the rates P at which the solar radial p
modes are expected to be excited. The solar models are computed with two
different local treatments of convection : the classical mixing-length theory
(MLT hereafter) and Canuto, Goldmann and Mazzitelli(1996, CGM hereafter)'s
formulation. For one set of solar models (EMLT and ECGM models), the atmosphere
is gray and assumes Eddington's approximation. For a second set of models (KMLT
and KCGM models), the atmosphere is built using a T(tau) law which has been
obtained from a Kurucz's model atmosphere computed with the same local
treatment of convection. The mixing-length parameter in the model atmosphere is
chosen so as to provide a good agreement between synthetic and observed Balmer
line profiles, while the mixing-length parameter in the interior model is
calibrated so that the model reproduces the solar radius at solar age. For the
MLT treatment, the rates P do depend significantly on the properties of the
atmosphere. On the other hand, for the CGM treatment, differences in P between
the ECGM and the KCGM models are very small compared to the error bars attached
to the seismic measurements. The excitation rates P for modes from the EMLT
model are significantly under-estimated compared with the solar seismic
constraints. The KMLT model results in intermediate values for P and shows also
an important discontinuity in the temperature gradient and the convective
velocity. On the other hand, the KCGM model and the ECGM model yield values for
P closer to the seismic data than the EMLT and KMLT models. We conclude that
the solar p-mode excitation rates provide valuable constraints and according to
the present investigation cleary favor the CGM treatment with respect to the
MLT.Comment: 4 pages, 3 figures, proceedings of the SOHO14/GONG 2004 workshop
"Helio- and Asteroseismology: Towards a Golden Future" from July 12-16 2004
at New Haven CT (USA
Rachel Emma Rothschild, Poisonous Skies: Acid Rain and the Globalization of Pollution (Chicago: University of Chicago Press, 2019)
Book Review of Rachel Emma Rothschild, Poisonous Skies: Acid Rain and the Globalization of Pollution (Chicago: University of Chicago Press, 2019
To build a gaming human interface device, designed for those with limited dexterity
With the competition in the games market focus is placed on entertaining the user for the sale of their products. This brings entertainment to the safe environment of the home. To play these games the user needs to use a keyboard and mouse.
For somebody without finger dexterity and limited arm movement, pressing keys on the keyboard is impossible without pressing other keys at the same time. The mouse is also impossible to use.
This project involves the design of a wireless controller made for an individual who has no finger dexterity, limited arm movement and has access to an optical head tracker to move the mouse cursor. The inputs are done by buttons and joysticks. The project requires careful design and testing to ensure the inputs can be operated by this individual.
The average time spent comfortably playing on the game controller was four hours. The delay coming from the controller was not noticeable for all the button presses. The processing time to do a key press by the controller was tested to be less than thirty two milliseconds. The battery that is in the controller will last for 16 hours of gameplay. The controller is mostly operated by the user so that less work is done by the carers. The only other method of playing games before the controller was to have a pointer glued into his splint. This could then be used to operate the mobile phone by using the pointer on the touch screen. The user found that computer gaming is more entertaining than playing games on a mobile phone
Brain structure and function in primary adrenal insufficiency
Individuals with primary adrenal insufficiency (PAI), i.e., congenital adrenal hyperplasia (CAH) and
autoimmune Addison’s disease (AAD), suffer from impaired production of the adrenal gland hormones
cortisol and aldosterone, and in the case of AAD, also androgens. Replacement medication for these
hormones is sub-optimal due to the difficulties in replicating the natural rhythms of cortisol secretion.
The hormones are known to affect brain function via many mechanisms, and both pre- and postnatal
hormone dysregulation may affect cognitive functioning, brain structure and brain function. Therefore,
studying brain health in PAI is of interest and is needed to optimise treatment and patient wellbeing.
The present thesis investigated brain structure related to cognitive functioning in individuals with CAH,
and cognitive functioning, brain structure and resting-state functional connectivity in individuals with
AAD. We found that individuals with CAH have impairments in white matter microstructure, as well
as cortical thinning of the frontoparietal network that was related to weaker performance on a
visuospatial working memory task. On the other hand, individuals with AAD performed equally to
control subjects on most measures of cognitive functions assessed with standardized tests during the
lab-visit, but they self-reported executive function problems in daily life, which were related to
experienced mental fatigue. As opposed to individuals with CAH, those with AAD did not have
profound differences in the structure of the brain, apart from smaller total brain volumes. However, they
displayed increased resting-state functional connectivity, particularly in primary visual regions and the
orbitofrontal cortex. Our results suggest that the effects of adrenal hormone insufficiency affect
individuals with CAH and AAD differently. This difference may be related to the onset of the disease,
which is from conception for those with CAH and in adolescence or adulthood for those with AAD.
Long-term follow-up studies are needed to assess whether the observed differences contribute to
increased cognitive decline later in life and how to optimise replacement medication to sustain brain
health
Stellar Fluxes as Probes of Convection in Stellar Atmospheres
Convection and turbulence in stellar atmospheres have a significant effect on
the emergent flux from late-type stars. The theoretical advancements in
convection modelling over recent years have proved challenging for the
observers to obtain measurements with sufficient precision and accuracy to
allow discrimination between the various predictions.
An overview of the current observational techniques used to evaluate various
convection theories is presented, including photometry, spectrophotometry, and
spectroscopy. The results from these techniques are discussed, along with their
successes and limitations.
The prospects for improved observations of stellar fluxes are also given.Comment: 3 pages, 1 figure; to appear in Convection in Astrophysics, Proc.
IAUS 239, F.Kupka, I.W. Roxburgh, K.L. Chan ed
Influence of local treatments of convection upon solar p mode excitation rates
We compute the rates P at which acoustic energy is injected into the solar
radial p modes for several solar models. The solar models are computed with two
different local treatments of convection: the classical mixing-length theory
(MLT hereafter) and Canuto et al (1996)'s formulation (CGM hereafter). Among
the models investigated here, our best models reproduce both the solar radius
and the solar luminosity at solar age and the observed Balmer line profiles.
For the MLT treatment, the rates P do depend significantly on the properties of
the atmosphere whereas for the CGM's treatment the dependence of P on the
properties of the atmosphere is found smaller than the error bars attached to
the seismic measurements. The excitation rates P for modes associated with the
MLT models are significantly underestimated compared with the solar seismic
constraints. The CGM models yield values for P closer to the seismic data than
the MLT models. We conclude that the solar p-mode excitation rates provide
valuable constraints and according to the present investigation clearly favor
the CGM treatment with respect to the MLT, although neither of them yields
values of P as close to the observations as recently found for 3D numerical
simulations.Comment: 11 pages, 7 figures, accepted for publication in Astronomy &
Astrophysic
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