49,978 research outputs found
Space photography and the exploration of Mars
A general exposition of the scientific potentialities and analytic framework of space photography is presented using the photography of Mars from flybys and orbiters as the principal example. Space photography is treated here as a communication process in which planetary scene information is communicated to the eye-brain receiver of earth-based interpreters. The salient parameters of this process are: (1) total information returned, (2) surface resolution, and (3) a priori knowledge regarding the planetary surface observed
Study of the application of perceptrons for prediction of solar flares. solar flare forecasting with a recognizing automaton final report, phase ii
Perceptrons for solar flare prediction with pattern recognition automato
Dynamical Self-assembly during Colloidal Droplet Evaporation Studied by in situ Small Angle X-ray Scattering
The nucleation and growth kinetics of highly ordered nanocrystal
superlattices during the evaporation of nanocrystal colloidal droplets was
elucidated by in situ time resolved small-angle x-ray scattering. We
demonstrated for the first time that evaporation kinetics can affect the
dimensionality of the superlattices. The formation of two-dimensional
nanocrystal superlattices at the liquid-air interface of the droplet has an
exponential growth kinetics that originates from interface "crushing".Comment: 4 pages, 4 figure
Cigarette smoking is associated with amplified age-related volume loss in subcortical brain regions
BACKGROUND:
Magnetic resonance imaging studies of cigarette smoking-related effects on human brain structure have primarily employed voxel-based morphometry, and the most consistently reported finding was smaller volumes or lower density in anterior frontal regions and the insula. Much less is known about the effects of smoking on subcortical regions. We compared smokers and non-smokers on regional subcortical volumes, and predicted that smokers demonstrate greater age-related volume loss across subcortical regions than non-smokers.
METHODS:
Non-smokers (n=43) and smokers (n=40), 22-70 years of age, completed a 4T MRI study. Bilateral total subcortical lobar white matter (WM) and subcortical nuclei volumes were quantitated via FreeSurfer. In smokers, associations between smoking severity measures and subcortical volumes were examined.
RESULTS:
Smokers demonstrated greater age-related volume loss than non-smokers in the bilateral subcortical lobar WM, thalamus, and cerebellar cortex, as well as in the corpus callosum and subdivisions. In smokers, higher pack-years were associated with smaller volumes of the bilateral amygdala, nucleus accumbens, total corpus callosum and subcortical WM.
CONCLUSIONS:
Results provide novel evidence that chronic smoking in adults is associated with accelerated age-related volume loss in subcortical WM and GM nuclei. Greater cigarette quantity/exposure was related to smaller volumes in regions that also showed greater age-related volume loss in smokers. Findings suggest smoking adversely affected the structural integrity of subcortical brain regions with increasing age and exposure. The greater age-related volume loss in smokers may have implications for cortical-subcortical structural and/or functional connectivity, and response to available smoking cessation interventions
Brain GABA and Glutamate Concentrations Following Chronic Gabapentin Administration: A Convenience Sample Studied During Early Abstinence From Alcohol.
Gabapentin (GBP), a GABA analog that may also affect glutamate (Glu) production, can normalize GABA and Glu tone during early abstinence from alcohol, effectively treating withdrawal symptoms and facilitating recovery. Using in vivo magnetic resonance spectroscopy, we tested the degree to which daily GBP alters regional brain GABA and Glu levels in short-term abstinent alcohol-dependent individuals. Regional metabolite levels were compared between 13 recently abstinent alcohol-dependent individuals who had received daily GBP for at least 1 week (GBP+) and 25 matched alcohol-dependent individuals who had not received GBP (GBP-). Magnetic resonance spectra from up to five different brain regions were analyzed to yield absolute GABA and Glu concentrations. GABA and Glu concentrations in the parieto-occipital cortex were not different between GBP- and GBP+. Glu levels in anterior cingulate cortex, dorsolateral prefrontal cortex, and basal ganglia did not differ between GBP- and GBP+. However, in a subgroup of individuals matched on age, sex, and abstinence duration, GBP+ had markedly lower Glu in the frontal white matter (WM) than GBP-, comparable to concentrations found in light/non-drinking controls. Furthermore, lower frontal WM Glu in GBP+ correlated with a higher daily GBP dose. Daily GBP treatment at an average of 1,600 mg/day for at least 1 week was not associated with altered cortical GABA and Glu concentrations during short-term abstinence from alcohol, but with lower Glu in frontal WM. GBP for the treatment of alcohol dependence may work through reducing Glu in WM rather than increasing cortical GABA
The Concordiensis, Volume 5, Number 9
Summer Song (poetry); History; Prophecy; Address; Salutatory; Class Oration; Ivy Oration; Honoriad
Editorial Department: Junion and Sophmore Prize; Speaking
Commencement; Obituary; Athletic Department
Local Department: Concordiensis Editors; Notice to Subscribers; President Potter\u27s Letter; In Memoriam; President Arthur\u27s Regretshttps://digitalworks.union.edu/concordiensis_1882/1005/thumbnail.jp
The Concordiensis, Volume 5, Number 7
Editorial Department: Comments on a Sermon; Williams College Freshmen; Where Are Our Commencement Exercises to be Held?; Our Stone Walk
Local Department: Phonographic Exhibition; Philomathean Officers; Seniors Visit to the Observatory; Cremation of Bourdon; Beaver and Cane Parade; Engineers Reception
Extranea Department; Exchange Department; Personal Department; Collegensia Department
Athletic Department: Lawn Tennis; Football; Athetic Contests, Etc.
Literary Department: A Holiday Jaunthttps://digitalworks.union.edu/concordiensis_1882/1003/thumbnail.jp
The Concordiensis, Volume 5, Number 1
Literary Department: Childhood (a poem); Young Men and Politics
Editorial Department: Welcome; Ponying; Improvements about College; A New Era in Chapel Excericses; The Varsity for 1881-82
Local Department: University Nine; Old Gillespie Club Room; Washburne Memorial Building; New Baseball Grounds; List of Freshman Class; Senior Class Officers; Gymnasium...
Baseball Column: The Yates Championship Cup; Entertainment for Raising Funds
Personal Department: Obituary, etc.
Memorial Services in Honor of President Garfield: Chapel Services; Resolutions of the Delta Upsilon Society
Exchange Department; Extranea Department; Collegensia Departmenthttps://digitalworks.union.edu/concordiensis_1881/1006/thumbnail.jp
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