Measurement of angular distributions of Drell-Yan dimuons in p+p interactions at 800 GeV/c.

We report a measurement of the angular distributions of Drell-Yan dimuons produced using an 800 GeV/c proton beam on a hydrogen target. The polar and azimuthal angular distribution parameters have been extracted over the kinematic range 4.5

Measurement of Upsilon production for p + p and p + d interactions at 800 GeV/c.

We report a high statistics measurement of Upsilon production with an 800 GeV/c proton beam on hydrogen and deuterium targets. The dominance of the gluon-gluon fusion process for Upsilon production at this energy implies that the cross section ratio, sigma(p+d-->Upsilon)/2sigma(p+p-->Upsilon), is sensitive to the gluon content in the neutron relative to that in the proton. Over the kinematic region 0

Measurement of angular distributions of Drell-Yan dimuons in p+d interactions at 800 GeV/c.

We report a measurement of the angular distributions of Drell-Yan dimuons produced using an 800 GeV/c proton beam on a deuterium target. The muon angular distributions in the dilepton rest frame have been measured over the kinematic range 4.5

The principles of techniques for cleaning root canals.

Chemomechanical preparation of the root canal includes both mechanical instrumentation and antibacterial irrigation, and is principally directed toward the elimination of micro-organisms from the root canal system. A variety of instruments and techniques have been developed and described for this critical stage of root canal treatment. Since their introduction in 1988, nickel-titanium (NiTi) rotary instruments have become a mainstay in clinical endodontics because of their exceptional ability to shape root canals with potentially fewer procedural complications. Safe clinical usage of NiTi instruments requires an understanding of basic metallurgy of the alloy including fracture mechanisms and their correlation to canal anatomy. This paper reviews the biologic principles of preparing root canals with an emphasis on correct use of current rotary NiTi instrumentation techniques and systems. The role and properties of contemporary root canal irrigants is also discussed.

Measurement of Neutron Decay Parameters-The abBA Experiment.

We are developing an experiment to measure the correlations a, A, and B, and the Fierz interference term b in neutron decay, with a precision of approximately 10(-4). The experiment uses an electromagnetic spectrometer in combination with two large-area segmented silicon detectors to detect the proton and electron from the decay in coincidence, with 4π acceptance for both particles. For the neutron-polarization-dependent observables A and B, precision neutron polarimetry is achieved through the combination of a pulsed neutron beam, under construction at the SNS, and a polarized (3)He neutron polarizer. Measuring a and A in the same apparatus provides a redundant determination of λ = gA/gV . Uncertainty in λ dominates the uncertainty of CKM unitarity tests.

J/psi polarization in 800-GeV p-Cu interactions.

We present measurements of the polarization of the J/psi produced in 800-GeV proton interactions with a copper target. Polarization of the J/psi is sensitive to the ccmacr; production and hadronization processes. A longitudinal polarization is observed at large x(F), while at small x(F) the state is produced essentially unpolarized or slightly transversely polarized. No significant variation of the polarization is observed versus p(T).

Observation of polarization in bottomonium production at square root of s = 38.8 GeV.

We present a measurement of the polarization observed for bottomonium states produced in p-Cu collisions at square root of s = 38.8 GeV. The angular distribution of the decay dimuons of the Upsilon(1S) state shows no polarization at small values of the fractional longitudinal momentum x(F) and transverse momentum p(T) but significant positive transverse production polarization for either p(T)>1.8 GeV/c or for x(F)>0.35. The Upsilon(2S+3S) (unresolved) states show a large transverse production polarization at all values of x(F) and p(T) measured. These observations challenge NRQCD calculations of the polarization expected in the hadronic production of bottomonium states.

Paraparesis due to syphilitic aortic dissection.

A patient is presented who developed an acute spinal cord infarct with paraparesis and segmental pain but no sensory or sphincter involvement. Investigations revealed an extensive dissecting thoracic aortic aneurysm and positive treponemal serologic findings consistent with tertiary cardiovascular syphilis.

Variability in measurement of extracranial internal carotid artery stenosis as displayed by both digital subtraction and magnetic resonance angiography: an assessment of three caliper techniques and visual impression of stenosis.

BACKGROUND AND PURPOSE: The degree of stenosis in the extracranial internal carotid artery helps predict the risk of an individual suffering subsequent cerebrovascular ischemic events. Different techniques have evolved to measure stenosis from angiograms, leading to some confusion and a call for the adoption of a single technique. To help choose the most reliable technique, this study assessed observer variability in reporting carotid stenosis for four different techniques, from both digital subtraction (DSA) and MR angiograms (MRA). Three of the techniques used caliper measurements; the fourth was the visual impression of stenosis. METHODS: From a total of 137 angiograms, caliper measurements were possible on 105 DSAs and 74 MRAs. Measurements from these angiograms were made by two independent observers on two separate occasions to assess interobserver and intraobserver variation in reporting. RESULTS: For DSA, the variability in reporting and the number of clinically significant differences arising as a result were similar for each of the four techniques. While the typical measurement errors for each of the techniques studied were on the order of +/- 5%, each technique produced some sizable individual differences for the same angiogram, with resultant wide 95% limits of agreement. Observer variability for reporting MRA was generally a little greater than for DSA. Compared with the caliper techniques, the visual impression of stenosis technique performed well, particularly for MRA. CONCLUSIONS: Although observer variability in reporting can be considerable, no important differences were found among the different techniques widely used for measuring carotid stenosis.

Observer variation in the interpretation of intra-arterial angiograms and the risk of inappropriate decisions about carotid endarterectomy.

OBJECTIVE: To determine how often observer variation in the interpretation of intra-arterial angiograms might alter the decision whether or not to refer patients for carotid surgery. METHODS: A prospective study was carried out in a consecutive series of 99 patients with transient ischaemic attacks and minor strokes. Interpretable angiographic films were available for 179 carotid artery bifurcations. Stenosis of the internal carotid artery was measured using mm scales, independently by three different radiologists (A, B, and C), using the European Carotid Surgery Trial method. RESULTS: An analysis of the grouped data showed good to moderate agreement by kappa statistics for radiologists A v B, B v C, and A v C of 0.68, 0.60, and 0.70 respectively. The mean absolute difference in the estimate of stenosis by each of the different radiologists (interobserver variation) was 9.5% and for each radiologist on two separate occasions (intraobserver variation) 8.4%. The degree of observer error was smallest among severely stenosed arteries. Although the absolute differences were small, "clinically important" differences which could change the treatment recommended from surgery to no surgery (or vice versa) occurred between radiologists A and B, B and C, and A and C in: seven (3.9%), six (3.4%), and 11 (6.1%) vessels respectively. CONCLUSIONS: Because observer variation affects all of the imaging methods (Doppler, duplex, contrast arteriography, and MR angiography) used to select patients with transient ischaemic attack and stroke, these findings are likely to be widely relevant. Any centre assessing patients with cerebrovascular disease will need to implement strict quality control measures in the interpretation of angiograms (and other vascular imaging procedures) to minimise observer error and thereby reduce the number of inappropriate decisions made to refer for carotid artery surgery or not.

Comparison of magnetic resonance angiography, duplex ultrasound, and digital subtraction angiography in assessment of extracranial internal carotid artery stenosis.

The results of a prospective study comparing ultrasound, intra-arterial digital subtraction angiography, and magnetic resonance angiography in the assessment of the degree of extracranial internal carotid artery stenosis are reported in patients with symptoms of recent carotid territory ischaemia. A total of 70 patients and 137 vessels were examined by all three techniques. The results obtained by each technique were reported blind. The mean difference (SD) for the comparison of magnetic resonance angiography and digital subtraction angiography was -0.7 (14)%, for ultrasound and digital subtraction angiography 3.1 (15)%, and for magnetic resonance angiography and ultrasound -3.8 (15)%. The level of agreement was greater for the more tightly stenosed vessels. With the assumption that the results of the digital subtraction angiogram reflect the true situation, the sensitivity and specificity in the detection of > or = 30% stenoses were 93% and 82% with ultrasound and 89% and 82% with magnetic resonance angiography; for stenoses > or = 70% 93% and 92% with ultrasound and 90% and 95% with magnetic resonance angiography; and for stenoses of 70-99% 89% and 93% with ultrasound and 86% and 93% with magnetic resonance angiography. For occlusion the values were 93% and 99% with ultrasound and 80% and 99% with magnetic resonance angiography. Increased sensitivity and specificity were obtained when analysis was confined to those vessels in which ultrasound and magnetic resonance angiography were in agreement over classification. It is thus possible to accurately categorize the degree of stenosis of the extracranial internal carotid artery from a combination of ultrasound and magnetic resonance angiography. The adoption of this combination for the investigation of patients before carotid endarterectomy removes the risk associated with conventional angiography and represents an important advance in the management of carotid stenosis.

Sequential Optimum Selection: a categorical alternative to discriminant analysis for conducting research in assessment.

Sequential Optimum Selection, SOS, a nonparametric computer-assisted alternative to discriminant analysis, was introduced and explicated. SOS is an iterative procedure that develops ongoing decision rules for discriminating among groups, successively expunging frequency distributions or classes until all cases are accounted for. In three illustrative comparisons using clinical assessment data, SOS proved competitive with discriminant analysis in terms of over-all hit rates for parsimonious extraction of meaningful variables. Further, in one demonstration using parametric data, SOS held up better on cross-validation. While discriminant analysis will, in most cases, yield better discrimination than SOS, the latter does not make parametric assumptions and should therefore be considered a viable alternative as an exploratory procedure.

A comparison of three Rorschach diagnostic systems and use of the Hand Test for detecting multiple personality disorder in outpatients.

Eleven individuals diagnosed with multiple personality disorder (MPD) on the basis of clinical observation by experienced therapists plus elevated scores on the Dissociative Experiences Scale (DES; Bernstein & Putnam, 1986) were administered the Rorschach Inkblot Test and the Hand Test. Results from the sample (n = 11) and a matched control group (N = 22) were analyzed and discussed in accordance with previous Rorschach diagnostic systems. The Wagner Signs diagnosed 91% (n = 10) of the MPD cases in this outpatient sample, with no false positives. The Labott Signs were found to have no utility, and the Barach Signs, when they occurred, seemed to be diagnostic of MPD but yielded a high rate of false negatives. Hand Test results were analyzed and found to be possibly diagnostic of MPD. Tentative criteria were proposed for its use as an additional tool for diagnosing MPD.

Behavioral specificity in the Rorschach human movement response: a comparison of strippers and models.

The presence of exhibitionism in actively exhibitionistic strippers and passively exhibitionistic models was confirmed when it was discovered that 40 out of 43 subjects produced at least one exhibitionistic (EXH) response on the Hand Test, which purportedly measures behavior. Subsequently, based on highly reliable ratings, it was found that the strippers produced significantly more active exhibitionistic human movement (M) responses on the Rorschach and the models more passive exhibitionistic M. This finding was interpreted as confirming Piotrowski's position that M represents reasonably specific overt behaviors. Implications were discussed, and an attempt was made to integrate past research on the Rorschach M score within the context of these findings.

Rorschach blends, IQ, and the effect of R.

A correlation of .351 was found between the Rorschach blend score and the Wechsler Adult Intelligence Scale Full Scale IQ (WAIS FSIQ) score for 70 outpatients. When the total number of responses (R) was partialed out, however, the correlation dropped to .255. We concluded that it is advisable to take into account the effects of R in validity studies showing significant but low correlations. The importance of further exploring the psychological implications of R was stressed.

Intrapleural bupivacaine in the control of postthoracotomy pain.

A randomized, double-blind trial was conducted to determine the effectiveness of intrapleural bupivacaine hydrochloride in the management of pain after thoracotomy. Thirty-three men and 7 women with a mean age of 62 years (range, 21 to 76 years) undergoing elective posterolateral thoracotomy were randomly allocated preoperatively to either a study group receiving 20 mL of 0.25% bupivacaine or a control group receiving 20 mL of 0.9% saline solution through a pleural catheter every 4 hours. Patients received supplementary doses of intramuscular papaveretum as required. Assessment of pain, somnolence, and breathing capacity was performed after the intrapleural injections at 4, 24, 48, and 72 hours postoperatively. Pain assessment, as measured by a linear analog scale, was lower in the bupivacaine group at all times, reaching significance at 4, 24, and 72 hours (p less than 0.05). The forced vital capacity and forced expiratory volume in 1 second at 6 weeks postoperatively remained significantly lower than preoperatively (p less than 0.05). The fall in forced vital capacity from this postoperative level was significantly less in the bupivacaine group at 4, 24, and 48 hours, and the fall in forced expiratory volume in 1 second was significantly less at 4 and 48 hours in the treated group. When used in conjunction with doses of parenteral narcotic, intrapleural bupivacaine gives better pain control with less respiratory depression than intermittent doses of narcotic alone.