9 research outputs found
Observation of diffractive orbits in the spectrum of excited NO in a magnetic field
We investigate the experimental spectra of excited NO molecules in the
diamagnetic regime and develop a quantitative semiclassical framework to
account for the results. We show the dynamics can be interpreted in terms of
classical orbits provided that in addition to the geometric orbits, diffractive
effects are appropriately taken into account. We also show how individual
orbits can be extracted from the experimental signal and use this procedure to
reveal the first experimental manifestation of inelastic diffractive orbits.Comment: 4 fig
Mesoscopic scattering in the half-plane: squeezing conductance through a small hole
We model the 2-probe conductance of a quantum point contact (QPC), in linear
response. If the QPC is highly non-adiabatic or near to scatterers in the open
reservoir regions, then the usual distinction between leads and reservoirs
breaks down and a technique based on scattering theory in the full
two-dimensional half-plane is more appropriate. Therefore we relate conductance
to the transmission cross section for incident plane waves. This is equivalent
to the usual Landauer formula using a radial partial-wave basis. We derive the
result that an arbitrarily small (tunneling) QPC can reach a p-wave channel
conductance of 2e^2/h when coupled to a suitable reflector. If two or more
resonances coincide the total conductance can even exceed this. This relates to
recent mesoscopic experiments in open geometries. We also discuss reciprocity
of conductance, and the possibility of its breakdown in a proposed QPC for atom
waves.Comment: 8 pages, 3 figures, REVTeX. Revised version (shortened), accepted for
publication in PR
The Determinants of Trade Credit in Transition Countries
The paper investigates the determinants of trade credit in transition countries. Traditional theories of trade credit extension suggest that both financial and commercial motives may induce non-financial companies to assume a role of financial intermediation. Furthermore, specific conditions of financing for companies in transition countries may reserve to trade credit an important role in financial structure. We test the determinants of accounts receivable and accounts payable on a sample of about 9300 companies from nine Central and Eastern European Countries. Results suggest that both financial and commercial motives explain the credit behaviour of firms. However, we do not find generalised patterns in the use of trade credit among all transition countries. Copyright Springer 2005trade credit, transition economies, G32, P34,
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Safety and tolerability of srx246, a vasopressin 1a antagonist, in irritable huntingtonâs disease patientsâa randomized phase 2 clinical trial
SRX246 is a vasopressin (AVP) 1a receptor antagonist that crosses the bloodâbrain barrier. It reduced impulsive aggression, fear, depression and anxiety in animal models, blocked the actions of intranasal AVP on aggression/fear circuits in an experimental medicine fMRI study and demonstrated excellent safety in Phase 1 multipleâascending dose clinical trials. The present study was a 3âarm, multicenter, randomized, placeboâcontrolled, doubleâblind, 12âweek, dose escalation study of SRX246 in early symptomatic Huntingtonâs disease (HD) patients with irritability. Our goal was to determine whether SRX246 was safe and well tolerated in these HD patients given its potential use for the treatment of problematic neuropsychiatric symptoms. Participants were randomized to receive placebo or to escalate to 120 mg twice daily or 160 mg twice daily doses of SRX246. Assessments included standard safety tests, the Unified Huntingtonâs Disease Rating Scale (UHDRS), and exploratory measures of problem behaviors. The groups had comparable demographics, features of HD and baseline irritability. Eightyâtwo out of 106 subjects randomized completed the trial on their assigned dose of drug. Oneâsided exactâmethod confidence interval tests were used to reject the null hypothesis of inferior tolerability or safety for each dose group vs. placebo. Apathy and suicidality were not affected by SRX246. Most adverse events in the active arms were considered unlikely to be related to SRX246. The compound was safe and well tolerated in HD patients and can be moved forward as a candidate to treat irritability and aggression. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]