Well-formedness judgment: A comparison of offline and online performance in Broca's aphasics

0na eg rcarmitimcaal tfieca tcuorem opfr ethhee nospieornat iodneafli cdietf i(nAitiCoDn )o ft hthaet frequently co-occurs with Broca’s aphasia is above-chance performance on well-formedness judgment tasks for many syntactic constructions, but impaired performance where syntactic binding of traces to their antecedents occurs. However, the methodologies used to establish this aspect of the performance profile of the ACD have been predominantly offline. Offline well-formedness tasks entail extralinguistic processing (e.g. perception, attention, short-term memory, conscious reflection) in varying amounts and the influence of such processes on parsing mechanisms is yet to be fully established. In order to (a) further understand the role of extra-linguistic processing on parsing, and (b) gain a more direct insight into the online nature of parsing in Broca’s aphasia, 8 subjects underwent a series of wellformedness judgment investigations using both offline and online test batteries. The sentence types and error types used were motivated by three current theories about the nature of the ACD, namely, the Trace-Based Account (Grodzinsky, 2000), the Mapping Hypothesis (Linebarger et al., 1983) and Capacity proposals (e.g. Frazier & Friederici, 1991). The results from the present investigation speak directly to the three aforementioned theories and also demonstrate the important role that extralinguistic processing plays during offline assessment. The clinical implications of the different outcomes from the offline vs. online tasks are also discussed.

Applications of accurate, high-precision Pb isotope ratio measurement by multi-collector ICP-MS

The isotope composition of Ph is difficult to determine accurately due to the lack of a stable normalisation ratio. Double and triple-spike addition techniques provide one solution and presently yield the most accurate measurements. A number of recent studies have claimed that improved accuracy and precision could also be achieved by multi-collector ICP-MS (MC-ICP-MS) Pb-isotope analysis using the addition of Tl of known isotope composition to Pb samples. In this paper, we verify whether the known isotope composition of Tl can be used for correction of mass discrimination of Pb with an extensive dataset for the NIST standard SRM 981, comparison of MC-ICP-MS with TIMS data, and comparison with three isochrons from different geological environments. When all our NIST SRM 981 data are normalised with one constant Tl-205/Tl-203 of 2.38869, the following averages and reproducibilities were obtained: Pb-207/Pb-206=0.91461+/-18; Pb-208/Ph-206 = 2.1674+/-7; and (PbPh)-Pb-206-Ph-204 = 16.941+/-6. These two sigma standard deviations of the mean correspond to 149, 330, and 374 ppm, respectively. Accuracies relative to triple-spike values are 149, 157, and 52 ppm, respectively, and thus well within uncertainties. The largest component of the uncertainties stems from the Ph data alone and is not caused by differential mass discrimination behaviour of Ph and Tl. In routine operation, variation of sample introduction memory and production of isobaric molecular interferences in the spectrometer's collision cell currently appear to be the ultimate limitation to better reproducibility. Comparative study of five different datasets from actual samples (bullets, international rock standards, carbonates, metamorphic minerals, and sulphide minerals) demonstrates that in most cases geological scatter of the sample exceeds the achieved analytical reproducibility. We observe good agreement between TIMS and MC-ICP-MS data for international rock standards but find that such comparison does not constitute the ultimate. test for the validity of the MC-ICP-MS technique. Two attempted isochrons resulted in geological scatter (in one case small) in excess of analytical reproducibility. However, in one case (leached Great Dyke sulphides) we obtained a true isochron (MSWD = 0.63) age of 2578.3 +/- 0.9 Ma, which is identical to and more precise than a recently published U-Pb zircon age (2579 3 Ma) for a Great Dyke websterite [Earth Planet. Sci. Lett. 180 (2000) 1-12]. Reproducibility of this age by means of an isochron we regard as a robust test of accuracy over a wide dynamic range. We show that reliable and accurate Pb-isotope data can be obtained by careful operation of second-generation MC-ICP magnetic sector mass spectrometers. (C) 2002 Elsevier Science B.V. All rights reserved.

Severity of sports-related concussion and neuropsychological test performance

Concussion severity grades according to the Cantu, Colorado Medical Society, and American Academy of Neurology systems were not clearly related to the presence or duration of impaired neuropsychological test performance in 21 professional rugby league athletes. The use of concussion severity guidelines and neuropsychological testing to assist return to play decisions requires further investigation.

The Limits of Rational Choice: New Institutionalism in the Test Bed of Central Banking Politics in Australia

This paper tests the explanatory capacities of different versions of new institutionalism by examining the Australian case of a general transition in central banking practice and monetary politics: namely, the increased emphasis on low inflation and central bank independence. Standard versions of rational choice institutionalism largely dominate the literature on the politics of central banking, but this approach (here termed RC1) fails to account for Australian empirics. RC1 has a tendency to establish actor preferences exogenously to the analysis; actors' motives are also assumed a priori; actor's preferences are depicted in relatively static, ahistorical terms. And there is the tendency, even a methodological requirement, to assume relatively simple motives and preference sets among actors, in part because of the game theoretic nature of RC1 reasoning. It is possible to build a more accurate rational choice model by re-specifying and essentially updating the context, incentives and choice sets that have driven rational choice in this case. Enter RC2. However, this move subtly introduces methodological shifts and new theoretical challenges. By contrast, historical institutionalism uses an inductive methodology. Compared with deduction, it is arguably better able to deal with complexity and nuance. It also utilises a dynamic, historical approach, and specifies (dynamically) endogenous preference formation by interpretive actors. Historical institutionalism is also able to more easily incorporate a wider set of key explanatory variables and incorporate wider social aggregates. Hence, it is argued that historical institutionalism is the preferred explanatory theory and methodology in this case.

Extensive multiple test centre evaluation of the VecTest malaria antigen panel assay

To determine which species and populations of Anopheles transmit malaria in any given situation, immunological assays for malaria sporozoite antigen can replace traditional microscopical examination of freshly dissected Anopheles. We developed a wicking assay for use with mosquitoes that identifies the presence or absence of specific peptide epitopes of circumsporozoite (CS) protein of Plasmodium falciparum and two strains of Plasmodium vivax (variants 210 and 247). The resulting assay (VecTest(TM) Malaria) is a rapid, one-step procedure using a 'dipstick' test strip capable of detecting and distinguishing between P. falciparum and P. vivax infections in mosquitoes. The objective of the present study was to test the efficacy, sensitivity, stability and field-user acceptability of this wicking dipstick assay. In collaboration with 16 test centres world-wide, we evaluated more than 40 000 units of this assay, comparing it to the standard CS ELISA. The 'VecTest(TM) Malaria' was found to show 92% sensitivity and 98.1% specificity, with 97.8% accuracy overall. In accelerated storage tests, the dipsticks remained stable for >15 weeks in dry conditions up to 45degreesC and in humid conditions up to 37degreesC. Evidently, this quick and easy dipstick test performs at an acceptable level of reliability and offers practical advantages for field workers needing to make rapid surveys of malaria vectors.

Angiotensinogen genotype, plasma protein and mRNA concentration in isolated systolic hypertension

Isolated systolic hypertension (ISH) occurs predominantly in the elderly, with a considerable morbidity and mortality. Its etiology is unknown but is likely to involve a significant genetic component. The aim of this study was to examine the angiotensinogen gene in ISH. The M235T and G(- 6)A polymorphisms were genotyped by polymerase chain reaction (PCR) in 86 ISH patients and 120 normotensive controls. Plasma angiotensinogen concentration was determined in 198 subjects by an indirect radioimmunoassay technique. Angiotensinogen mRNA concentration was determined by quantitative competitive reverse transcription (RT)-PCR in subcutaneous adipose tissue from a subset of these patients (n = 8) and controls (n = 6). Both the M235T (p = 0.0015) and G(- 6)A (p = 0.029) polymorphisms were associated with ISH. Plasma angiotensinogen concentration was higher in patients than controls (p < 0.0001), but was not associated with genotype. Angiotensinogen mRNA concentration in adipose tissue from ISH subjects was significantly lower than in adipose tissue from normotensive subjects (p = 0.033). The association of angiotensinogen gene variants with ISH and the elevation of plasma angiotensinogen concentration in these patients suggests a role of the angiotensinogen gene in this form of hypertension. Angiotensinogen gene expression may be altered in ISH, but this requires further examination.

Effects of dofetilide on cardiovascular tissues from normo- and hypertensive rats

The aim was to test whether dofetilide has some potential for use in the treatment of heart failure. Dofetilide at less than or equal to 3 x 10(-5) m had no effect on the quiescent Wistar Kyoto (WKY) rat aorta, mesenteric and intralobar arteries, or the spontaneous contractions of the WKY rat portal vein. Dofetilide at 10(-6) to 3 x 10(-5) m relaxed the KCl-contracted aorta. Dofetilide at 10(-9)-10(-7) m augmented the force of contraction of left ventricle strips from 12- and 18-month-old WKY rats at 2 Hz. Spontaneously hypertensive rats (SHRs) at 12 and 17-21 months of age are models of cardiac hypertrophy and failure, respectively. The augmentation of force at 2 Hz with dofetilide was similar on 12- and 18-month-old WKY rats and 12-month-old SHRs but reduced on the 18-month-old SHR left ventricle. At a higher more physiological frequency, 4 Hz, the threshold concentration of dofetilide required to augment the force responses of 21-month-old SHR left ventricles was markedly increased and the maximum augmenting effect was decreased. Dofetilide at 10(-7)-10(-5) m reduced the rate of the 17-month-old WKY rat right atrium, and had a similar effect on age-matched SHR right atrium. In summary, dofetilide is a positive inotrope and negative chronotrope in the rat. However, as the positive inotropic effect is not observed with clinically relevant concentrations at a physiological rate in heart failure, dofetilide is unlikely to be useful as a positive inotrope in the treatment of heart failure.

Do increases in xylem sap pH and/or ABA concentration mediate stomatal closure following nitrate deprivation?

Stomatal conductance (g(s)) of pepper (Capsicum annuum L.) plants decreased during the second photoperiod (day 2) after withholding nitrate (N). Stomatal closure of N-deprived plants was not associated with a decreased shoot water potential (Psi(shoot)); conversely Psi(shoot) was lower in N-supplied plants. N deprivation transiently (days 2 and 3) alkalized (0.2-0.3 pH units) xylem sap exuded from de-topped root systems under root pressure, and xylem sap expressed from excised shoots by pressurization. The ABA concentration of expressed sap increased 3-4-fold when measured on days 2 and 4. On day 2, leaves detached from N-deprived and N-supplied plants showed decreased transpiration rates when fed an alkaline (pH 7) artificial xylem (AX) solution, independent of the ABA concentration (10-100 nM) supplied. Thus changes in xylem sap composition following N deprivation can potentially close stomata. However, the lower transpiration rate of detached N-deprived leaves relative to N-supplied leaves shows that factors residing within N-deprived leaves also mediate stomatal closure, and that these factors assume greater importance as the duration of N deprivation increases.

Relationship between cranio-cervical flexion range of motion and pressure change during the cranio-cervical flexion test

The purpose of this study was to quantify the sagittal angular displacement of the head (cranio-cervical flexion) for the five incremental stages of the cranio-cervical flexion test (CCFT). Range of cranio-cervical flexion during the CCFT was measured using a digital imaging method in 20 healthy volunteer subjects. The intra- and inter-rater reliability of the digital imaging technique for the assessment of this movement were also examined. The results of this study demonstrated a linear relationship between the incremental pressure targets of the CCFT and the percentages of full range cranio-cervical flexion range of motion (ROM) measured in the supine lying position of the test using a digital imaging technique. A mean of 22.9% full range cranio-cervical flexion was used to reach the first pressure target of the CCFT followed by linear increments up to 76.6% for the last stage of the test. An increasing amount of cranio-cervical flexion ROM was used to achieve the five successive stages of the CCFT reflecting an increasing contractile demand on the deep cervical flexor muscles. Excellent inter-rater (ICC = 0.994) and intra-rater reliability (ICC = 0.988-0.998) were demonstrated for the angular measurements using this digital imaging technique. (C) 2003 Elsevier Science Ltd. All rights reserved.