Extended Classical Over-Barrier Model for Collisions of Highly Charged Ions with Conducting and Insulating Surfaces

We have extended the classical over-barrier model to simulate the neutralization dynamics of highly charged ions interacting under grazing incidence with conducting and insulating surfaces. Our calculations are based on simple model rates for resonant and Auger transitions. We include effects caused by the dielectric response of the target and, for insulators, localized surface charges. Characteristic deviations regarding the charge transfer processes from conducting and insulating targets to the ion are discussed. We find good agreement with previously published experimental data for the image energy gain of a variety of highly charged ions impinging on Au, Al, LiF and KI crystals.Comment: 32 pages http://pikp28.uni-muenster.de/~ducree

Single photon emission computed tomography (SPECT) of anxiety disorders before and after treatment with citalopram

BACKGROUND: Several studies have now examined the effects of selective serotonin reuptake inhibitor (SSRI) treatment on brain function in a variety of anxiety disorders including obsessive-compulsive disorder (OCD), posttraumatic stress disorder (PTSD), and social anxiety disorder (social phobia) (SAD). Regional changes in cerebral perfusion following SSRI treatment have been shown for all three disorders. The orbitofrontal cortex (OFC) (OCD), caudate (OCD), medial pre-frontal/cingulate (OCD, SAD, PTSD), temporal (OCD, SAD, PTSD) and, thalamic regions (OCD, SAD) are some of those implicated. Some data also suggests that higher perfusion pre-treatment in the anterior cingulate (PTSD), OFC, caudate (OCD) and antero-lateral temporal region (SAD) predicts subsequent treatment response. This paper further examines the notion of overlap in the neurocircuitry of treatment and indeed treatment response across anxiety disorders with SSRI treatment. METHODS: Single photon emission computed tomography (SPECT) using Tc-(99 m )HMPAO to assess brain perfusion was performed on subjects with OCD, PTSD, and SAD before and after 8 weeks (SAD) and 12 weeks (OCD and PTSD) treatment with the SSRI citalopram. Statistical parametric mapping (SPM) was used to compare scans (pre- vs post-medication, and responders vs non-responders) in the combined group of subjects. RESULTS: Citalopram treatment resulted in significant deactivation (p = 0.001) for the entire group in the superior (t = 4.78) and anterior (t = 4.04) cingulate, right thalamus (t = 4.66) and left hippocampus (t = 3.96). Deactivation (p = 0.001) within the left precentral (t = 4.26), right mid-frontal (t = 4.03), right inferior frontal (t = 3.99), left prefrontal (3.81) and right precuneus (t= 3.85) was more marked in treatment responders. No pattern of baseline activation distinguished responders from non-responders to subsequent pharmacotherapy. CONCLUSIONS: Although each of the anxiety disorders may be mediated by different neurocircuits, there is some overlap in the functional neuro-anatomy of their response to SSRI treatment. The current data are consistent with previous work demonstrating the importance of limbic circuits in this spectrum of disorders. These play a crucial role in cognitive-affective processing, are innervated by serotonergic neurons, and changes in their activity during serotonergic pharmacotherapy seem crucial

Lawn and ornamentals research, 1966

Lawn grasses, mixtures, and blends / R. R. Davis -- Kentucky bluegrass varieties / M. H. Niehaus and R. R. Davis -- Bentgrass varieties for golf courses and lawns / R. W. Miller and R. R. Davis -- Spot treatment for perennial grass weeds / G. B. Triplett, Jr. and R. R. Davis -- Turf insect problems / J. B. Polivka -- Diseases of turfgrasses / H. A. Runnels -- Stripe smut of merion Kentucky bluegrass / R. E. Partyka -- Shade trees for yard and street beautification / O. D. Diller -- Fifty outstanding shade and ornamental trees / L. C. Chadwick -- Fifty choice shrubs and small trees / L. C. Chadwick -- Fifty outstanding shrubs and small trees with ornamental fruits / L. C. Chadwick -- Some recommended uncommon shrubs / L. C. Chadwick and K. W. Reisch -- Taxus--Yew / L. C. Chadwick and K. W. Reisch -- The viburnums / K. W. Reisch -- Pruning ornamental plants / K. W. Reisch and L. C. Chadwick -- Woody plant viability research / K. W. Reisch and F. K. Buscher -- Freeze injury on ornamental plants--Spring 1966 / K. W. Reisch and L. C. Chadwick -- Wilt diseases of trees and problems associated with control / G. J. Bar