2,258 research outputs found
The Milky Way's stellar halo - lumpy or triaxial?
We present minimum chi-squared fits of power law and Hernquist density
profiles to F-turnoff stars in eight 2.5 deg wide stripes of SDSS data: five in
the North Galactic Cap and three in the South Galactic cap. Portions of the
stellar Galactic halo that are known to contain large streams of tidal debris
or other lumpy structure, or that may include significant contamination from
the thick disk, are avoided. The data strongly favor a model that is not
symmetric about the Galaxy's axis of rotation. If included as a free parameter,
the best fit to the center of the spheroid is surprisingly approx 3 kpc from
the Galactic center in the direction of the Sun's motion. The model fits favor
a low value of the density of halo stars at the solar position. The alternative
to a non-axisymmetric stellar distribution is that our fits are contaminated by
previously unidentified lumpy substructure.Comment: 10 pages, 10 figs, to appear in proceedings of conference "Physics at
the end of the Galactic Cosmic Ray Spectrum", Journal of Physics: Conf.
series, eds. G. Thomson and P. Sokolsk
Noninvasive Brain Stimulation and Personal Identity: Ethical Considerations.
As noninvasive brain stimulation (NIBS) technology advances, these methods may become increasingly capable of influencing complex networks of mental functioning. We suggest that these might include cognitive and affective processes underlying personality and belief systems, which would raise important questions concerning personal identity and autonomy. We give particular attention to the relationship between personal identity and belief, emphasizing the importance of respecting users\u27 personal values. We posit that research participants and patients should be encouraged to take an active approach to considering the personal implications of altering their own cognition, particularly in cases of neurocognitive enhancement. We suggest that efforts to encourage careful consideration through the informed consent process would contribute usefully to studies and treatments that use NIBS
Improving the Accuracy of DaT Scan Interpretation: a retrospective study to identify variables that standardize the review of DaT scans for idiopathic Parkinson’s disease
Introduction: Until recently, the diagnosis of Parkinson’s disease (PD) has been based solely on clinical observation. The DaT scan is a tool that allows clinicians to visualize areas of neurodegeneration in PD and can help guide diagnosis. However, there is a discordance between clinical judgement and interpretation of DaT scans. In this study, we aim to improve the utility of DaT scans in the diagnosis of PD by identifying factors that can lead to a misdiagnosis and determine which image findings predict a clinical syndrome of parkinsonism.
Methods: We will conduct a retrospective chart review to analyze DaT scans of 100 patients clinically diagnosed with PD. We will calculate the initial SN/SP/PPV/NPV for diagnoses based clinically compared to scan. We will then blindly review and reclassify all scans as definitely abnormal, definitely normal, or indeterminate. We will then recalculate a revised SN/SP/PPV/NPV to see if these values changed following reanalysis. From the discordant scans, we will attempt to identify factors that can further assist in interpreting DaT scans.
Results: Patients have been identified and we are in the process of extracting data. We anticipate that after systematic, careful re-review, the specificity of DaT scans will be higher, due to improvement in identifying positive scans.
Discussion: Imaging can be costly and cumbersome for patients and clinicians alike. Currently, DaT scans do not offer an improved accuracy in diagnosis over clinical judgement. If the interpretation of DaT scans can be optimized, they will be of greater utility to both patients and physicians
The Norumbega Fault Zone between Bath and Freedom, Maine
Guidebook for field trips in southwestern Maine: New England Intercollegiate Geological Conference, 78th annual meeting, Bates College, Lewiston, Maine, October 17, 18, and 19, 1986: Trip A-
Recommended from our members
Perceptions of General and Situational Influence in Predicting Negative Conflict Behavior: The Moderating Role of Attachment Style
Because of the numerous ways to operationalize power, much of the literature about power in relationships has not been cohesive. However, to understand when and how perceptions of power are associated with behaviors in relationships, multiple conceptualizations of power must be considered along with personal characteristics. The present study tested how perceptions of general power and situational power interact to predict negative behaviors during relationship conflict for people of various attachment orientations. Additionally, we tested if effects remained stable or changed over the early years of marriage. We found that low general and low situational influence did interact to predict less hostility than different combinations of influence, which did not support my hypothesis. Largely, we did not find systematic support that attachment style was a relevant moderator in considering influence and negative conflict behavior, with one interaction between general influence, situational influence, gender, and avoidance as an exception. Finally, we found that the proposed effects did not differ over time
Klipsun Magazine, 1978, Volume 08, Issue 05 - June
https://cedar.wwu.edu/klipsun_magazine/1042/thumbnail.jp
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