T. G. Zimmerer to Mr. James Meredith (1 October 1962)

https://egrove.olemiss.edu/mercorr_pro/1402/thumbnail.jp

Luminescence evidence for bulk and surface excitons in free xenon clusters

Cathodoluminescence spectra of free xenon clusters produced by condensation of xenon-argon gas mixtures in supersonic jets expanding into vacuum were studied. By varying initial experimental parameters, including xenon concentration, we could obtain clusters with a xenon core (300-3500 atoms) covered by an argon outer shell as well as shell-free xenon clusters (about 1500 atoms). The cluster size and temperature (about 40 K for both cases) were measured electronographically. Luminescence bands evidencing the existence of bulk and surface excitons were detected for shell-free xenon clusters. The emission from bulk excitons in small clusters is supposed to be due to processes of their multiple elastic reflections from the xenon-vacuum interface. A presence of an argon shell causes extinction of the excitonic bands. In addition, some new bands were found which have no analogs for bulk xenon cryosamples.Comment: The final modified version will be published in Phys. Rev. A 76 (2007

"I don't know": a usage-based approach to familiar collocations in non-fluent aphasia

Background: Familiar collocations (e.g., “it’s alright”) are an important part of everyday conversation. Such word combinations are often retained in speakers with Broca’s aphasia. However, only few investigations have studied the forms and functions of familiar collocations available to speakers with Broca’s aphasia. // Aims: We first apply a frequency-based perspective to word combinations produced by speakers with Broca’s aphasia and their conversation partners (CPs), and compare the frequency characteristics of word combinations in dyadic and non-dyadic speech. Second, we investigate the conversational functions of one prominent familiar collocation, “I don’t know” (IDK). // Methods & Procedures: In the first analysis, speech samples from interactions of nine dyads (each a speaker with Broca’s aphasia and their CP) were examined. Non-dyadic samples were selected from 39 speakers with Broca’s aphasia from AphasiaBank (MacWhinney et al., 2011). The Frequency in Language Analysis Tool (FLAT; Zimmerer & Wibrow, 2015) was used to estimate collocation strength (the degree of association between words in a combination) of well-formed bigrams (two-word combinations) and trigrams (three-word combinations). The second analysis presents a qualitative investigation of uses of IDK in dyadic exchanges. // Outcomes & Results: Analysis 1 revealed that residual trigrams in Broca’s aphasia were more strongly collocated in comparison to language produced by CPs. There was no difference in frequency-based profiles between dyadic and non-dyadic aphasic speech. Analysis 2 indicated that speakers with Broca’s aphasia and CPs used IDK to achieve a variety of communicative functions. However, patterns specific to each participant group were found. // Conclusions: These findings highlight that frequency-based analysis is useful in explaining residual, grammatically well-formed word combinations in Broca’s aphasia. This study provides evidence that IDK can aid turn construction in aphasia

Exciton-induced lattice defect formation

The lattice defect formation in solid Ne induced by electronic excitation was studied using the selective vacuum ultraviolet spectroscopy method. The samples were excited with synchrotron radiation in the range of excitonic absorption n = 2Г(3/2). The dose dependence of the intensity distribution in the band of atomic type self-trapped exciton luminescence was analyzed. A direct evidence of the formation and accumulation of point lattice defects in solid Ne via the excitonic mechanism was obtained for the first time. The model of the permanent lattice defect formation is discussed

Influencing Test Ordering In Primary Care Using Influential Physicians

The purpose of this study was to evaluate the use of influential physicians to influencetest ordering in a primary care setting. Structured order forms for three commonly orderedtests were developed in conjunction with the chief residents in internal medicineand family practice at Methodist Hospital of Indiana, a 1120 bed private teachinghospital. After data were collected for a nine month baseline period, the forms wereintroduced by the chief residents to the house staff in the Adult Ambulatory Care Centerand the Family Practice Center. After two months, the study was discontinued. Thedata were analyzed using a multivariate analysis of variance with repeated measuresand paired t-tests. Test ordering rates for complete blood counts were significantlyreduced in both centers. Urinalysis rates were significantly reduced in the FamilyPractice Center. There was no significant effect of the intervention on ordering ratesfor the chemistry-23 test. The findings suggest that the use of influential physicians isan effective way to change physician behavior in primary care settings

Exciton self-trapping into diatomic and triatomic molecular complexes in xenon cryocrystals

The recent study of molecular trapped centers in Xe cryocrystals was extended on triatomic self-trapped excitons. Time- and spectrally-resolved molecular luminescence was measured in the temperature range 5–60 K. The processes of intrinsic exciton self-rapping into diatomic and triatomic molecular complexes and extrinsic exciton trapping at lattice imperfections were separated by selective photoexcitation of Xe cryocrystals by synchrotron radiation. The temperature dependencies of triplet lifetimes of molecular exciton subbands were measured for the first time