A computer model of global thermospheric winds and temperatures

A computer model of the global, time-dependent, thermospheric horizontal vector neutral wind and neutral temperature fields has been constructed based on output from the NCAR thermospheric general circulation model (NCAR-TGCM). The wind field is represented by a vector spherical harmonic (VSH) expansion in the horizontal, a fourier expansion in Universal Time, and a polynomial expansion in altitude. The global temperature field representation differs in that a scalar spherical harmonic expansion is used in the horizontal and a Bates model temperature profile is used in altitude. A set of suitably-truncated spectral coefficients contains the wind and temperature description for a diurnally-reproducible run of the NCAR-TGCM. The VSH model is coded in a FORTRAN subroutine that returns vector wind and temperature values for a given UT, geographic location, and altitude. The model has applicability for studies of thermospheric and/or ionospheric physics were reasonable time-dependent neutral wind and temperature values are of interest. The routine is novel since portable computer models of thermospheric wind fields have not previously been available to researchers. The current version of the model is valid for solar maximum, December solstice only, although the model can be extended to any season and specific set of geophysical conditions for which TGCM results are available. Results from the VSH computer model are presented to compare with global-scale wind measurements from the Dynamics Explorer (DE-2) satellite. The agreement between the computer model results and data from individual orbits of DE-2 is good, indicating that the model provides reasonable wind values, having the appropriate characteristic latitudinal, diurnal, and Universal-Time-dependent signatures observed from the satellite at upper thermospheric altitudes. The VSH thermospheric temperature values are in general agreement with MSIS-83 temperatures but illustrate smaller-scale horizontal temperature structures than are resolved by MSIS-83, owing to the larger number of spectral harmonics retained.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26911/1/0000477.pd

Empowerment or Engagement? Digital Health Technologies for Mental Healthcare

We argue that while digital health technologies (e.g. artificial intelligence, smartphones, and virtual reality) present significant opportunities for improving the delivery of healthcare, key concepts that are used to evaluate and understand their impact can obscure significant ethical issues related to patient engagement and experience. Specifically, we focus on the concept of empowerment and ask whether it is adequate for addressing some significant ethical concerns that relate to digital health technologies for mental healthcare. We frame these concerns using five key ethical principles for AI ethics (i.e. autonomy, beneficence, non-maleficence, justice, and explicability), which have their roots in the bioethical literature, in order to critically evaluate the role that digital health technologies will have in the future of digital healthcare

Come back Marshall, all is forgiven? : Complexity, evolution, mathematics and Marshallian exceptionalism

Marshall was the great synthesiser of neoclassical economics. Yet with his qualified assumption of self-interest, his emphasis on variation in economic evolution and his cautious attitude to the use of mathematics, Marshall differs fundamentally from other leading neoclassical contemporaries. Metaphors inspire more specific analogies and ontological assumptions, and Marshall used the guiding metaphor of Spencerian evolution. But unfortunately, the further development of a Marshallian evolutionary approach was undermined in part by theoretical problems within Spencer's theory. Yet some things can be salvaged from the Marshallian evolutionary vision. They may even be placed in a more viable Darwinian framework.Peer reviewedFinal Accepted Versio

A novel online food recall checklist for use in an undergraduate student population : a comparison with diet diaries

Peer reviewedPublisher PD

The Non-linear Dynamics of Meaning-Processing in Social Systems

Social order cannot be considered as a stable phenomenon because it contains an order of reproduced expectations. When the expectations operate upon one another, they generate a non-linear dynamics that processes meaning. Specific meaning can be stabilized, for example, in social institutions, but all meaning arises from a horizon of possible meanings. Using Luhmann's (1984) social systems theory and Rosen's (1985) theory of anticipatory systems, I submit equations for modeling the processing of meaning in inter-human communication. First, a self-referential system can use a model of itself for the anticipation. Under the condition of functional differentiation, the social system can be expected to entertain a set of models; each model can also contain a model of the other models. Two anticipatory mechanisms are then possible: one transversal between the models, and a longitudinal one providing the modeled systems with meaning from the perspective of hindsight. A system containing two anticipatory mechanisms can become hyper-incursive. Without making decisions, however, a hyper-incursive system would be overloaded with uncertainty. Under this pressure, informed decisions tend to replace the "natural preferences" of agents and an order of cultural expectations can increasingly be shaped

Defining appropriateness in coach-athlete sexual relationships: The voice of coaches

The sporting culture, with omnipotent coaches, fierce competition for recognition and funding, and ‘win at all cost’ ethos, creates an environment conducive to sexual exploitation of athletes. Recent increased public awareness and the development of child protection policies in sport have led to the questioning of previously accepted coach-athlete relationships. This study is an exploratory investigation into male swimming coaches’ perceptions of appropriateness of coach-athlete sexual relationships. Sexual relationships with athletes under the age of 16 were unanimously considered totally inappropriate. With regard to sexual relationships with athletes above the age of consent for heterosexual sex, opinions ranged from “totally inappropriate” to “it’s a question of civil liberties.” These results are discussed in relation to how coaches have adapted their own behaviours in the face of public scrutiny but are still reluctant to restrict the rights of their fellow coaches

The anti-inflammatory effects of dimethyl fumarate in astrocytes involve glutathione and haem oxygenase-1

DMF (dimethyl fumarate) exerts anti-inflammatory and pro-metabolic effects in a variety of cell types, and a formulation (BG-12) is being evaluated for monotherapy in multiple sclerosis patients. DMF modifies glutathione (GSH) levels that can induce expression of the anti-inflammatory protein HO-1 (haem oxygenase-1). In primary astrocytes and C6 glioma cells, BG-12 dose-dependently suppressed nitrite production induced by either LI [LPS (lipopolysaccharide) at 1 \u3bcg/ml plus IFN\u3b3 (interferon \u3b3) at 20 units/ml] or a mixture of pro-inflammatory cytokines, with greater efficacy in C6 cells. BG-12 reduced NOS2 (nitric oxide synthase 2) mRNA levels and activation of a NOS2 promoter, reduced nuclear levels of NF-\u3baB (nuclear factor \u3baB) p65 subunit and attenuated loss of I\u3baB\u3b1 (inhibitory \u3baB\u3b1) in both cell types, although with greater effects in astrocytes. In astrocytes, LI decreased mRNA levels for GSHr (GSH reductase) and GCL (c-glutamylcysteine synthetase), and slightly suppressed GSHs (GSH synthetase) mRNAs. Co-treatment with BG-12 prevented those decreased and increased levels above control values. In contrast, LI reduced GSHp (GSH peroxidase) and GCL in C6 cells, and BG-12 had no effect on those levels. BG-12 increased nuclear levels of Nrf2 (nuclear factor-erythroid 2 p45 subunit-related factor 2), an inducer of GSH-related enzymes, in astrocytes but not C6 cells. In astrocytes, GSH was decreased by BG-12 at 2 h and increased at 24 h. Prior depletion of GSH using buthionine-sulfoximine increased the ability of BG-12 to reduce nitrites. In astrocytes, BG-12 increased HO-1 mRNA levels and effects on nitrite levels were blocked by an HO-1 inhibitor. These results demonstrate that BG-12 suppresses inflammatory activation in astrocytes and C6 glioma cells, but with distinct mechanisms, different dependence on GSH and different effects on transcription factor activation

A comparison of wind observations of the upper thermosphere from the dynamics explorer satellite with the predictions of a global time-dependent model

Seven polar passes of the NASA Dynamics Explorer 2 (DE-2) satellite during October and early December 1981 have been used to examine the high-latitude circulation in the upper thermosphere. Vector winds along the satellite track are derived by appropriate merging of the data from the remote-sensing Fabry-Perot interferometer (meridional wind) and the in situ wind and temperature spectrometer (zonal wind) and are compared with the predictions of a three-dimensional, time-dependent, global model of the thermosphere. Major features of the experimental winds, such as the mean day to night circulation caused by solar u.v. and e.u.v. heating, augmented by magnetospheric processes at high latitude and the sharp boundaries and flow reversals imposed on thermospheric winds by momentum transfer (ion drag) from the magnetosphere, are qualitatively explained by a version of the global model using a semi-empirical global model of polar electric fields (Volland Model 2 or Heppner Model A) and a model of global electron density which excludes the effects of high-latitude geomagnetic processes. A second version of the global dynamic model includes a theoretical model of the high-latitude ionosphere which is self-consistent and reflects the enhancement of ionization due to magnetospheric phenomena acting in addition to solar e.u.v. photo-ionization, including the interactive processes which occur between ionization and high latitude ion convection and thermospheric winds. This second dynamical model shows an improved comparison with the structure and magnitude of polar cap and auroral oval winds at times of other than extremely low geomagnetic activity, when the first model appears a better match. An improved empirical description of the complex magnetospheric processes exciting the thermosphere in the vicinity of the dayside polar cusp and an empirical description of storm-time electric fields will be required for a quantitative explanation of the polar thermospheric winds during geomagnetic substorm events.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25079/1/0000510.pd

A New Approach to Searching for Dark Matter Signals in Fermi-LAT Gamma Rays

Several cosmic ray experiments have measured excesses in electrons and positrons, relative to standard backgrounds, for energies from ~ 10 GeV - 1 TeV. These excesses could be due to new astrophysical sources, but an explanation in which the electrons and positrons are dark matter annihilation or decay products is also consistent. Fortunately, the Fermi-LAT diffuse gamma ray measurements can further test these models, since the electrons and positrons produce gamma rays in their interactions in the interstellar medium. Although the dark matter gamma ray signal consistent with the local electron and positron measurements should be quite large, as we review, there are substantial uncertainties in the modeling of diffuse backgrounds and, additionally, experimental uncertainties that make it difficult to claim a dark matter discovery. In this paper, we introduce an alternative method for understanding the diffuse gamma ray spectrum in which we take the intensity ratio in each energy bin of two different regions of the sky, thereby canceling common systematic uncertainties. For many spectra, this ratio fits well to a power law with a single break in energy. The two measured exponent indices are a robust discriminant between candidate models, and we demonstrate that dark matter annihilation scenarios can predict index values that require "extreme" parameters for background-only explanations.Comment: v1: 11 pages, 7 figures, 1 table, revtex4; v2: 13 pages, 8 figures, 1 table, revtex4, Figure 4 added, minor additions made to text, references added, conclusions unchanged, published versio

"An infinitude of Possible Worlds": towards a research method for hypertext fiction

While the investigation of creative writing as a research method is gathering apace, little work has been done into the specific case of hypertext fiction (fiction written through a digital medium). This paper argues that, while there remain certain similarities between paper-based and digital texts, fundamental differences in design and construction remain. If hypertext fictions are to be successfully understood, then the role and purpose of the digital writer needs to be more fully analysed as part of the creative process. This paper argues that Possible Worlds Theory offers a way forward. With its focus on the ontological structures created by hypertext fiction, Possible World Theory actively embraces narrative indeterminacy and ontological changeability. In this sense the method provides a structured means by which the creative manipulation of the unique affordances of a digital medium by a writer can be theorised