Problematic Methods in the Assessment of Scholarly Productivity in Clinical PhD Programs

We review the methods in the ranking of clinical psychology doctoral programs provided by Stewart, Roberts, and Roy (2007). Using our own program as an example, we identify several areas of concern (e.g., authorship credits, criteria applied, faculty attrition). The inaccuracies identified for our program ranking, in combination with methodological concerns highlighted by previous commentaries, suggest that the validity of the rankings can be called into question.     

The measurement of the tacticity of poly(vinyl chloride) by 13C nuclear magnetic resonance spectroscopy

Fourier transform ¹H-decoupled ¹³C NMR spectra were obtained on seven poly(vinyl chloride), (PVC), samples in solution in o-dichlorobenzene. Four of the polymers were of the commercial type and the others were prepared by suspension polymerisation at +90°C, +5°C, and -30°C. Measurements of the spectra were used to assess the precision and accuracy with which information about the tacticity of PVC can be obtained from such spectra. The results show that the well-resolved α-carbon triad and β-carbon tetrad spectra obtained may be reliably analysed to give values of the probability of syndiotactic placement with a precision of about 0,005 for measurements on a single run on a single sample. The simplest and probably the most reliable method of measuring the areas under the peaks which correspond to specific triads ot tetrads is to use the spectrometer integrator, although results of slightly lower precision may be obtained by the use of a curve resolver. Consideration of possible systematic errors due to different T₁ relaxation times, unequal nuclear Overhauser enhancement (NOE) factors, and incomplete dissolution of the polymer has shown that the only one of these which is possibly significant is that due to NOE, which is almost certainly less than 0,008, so that the absolute accuracies of the P_r values should be better than that. A more detailed study of the data shows that the polymers made at 5°C and -30°C are almost certainly non-Bernoullian and that firstoder Markov statistics can adequately describe the observed departures from Bernoullian statistics. These departures may have significant consequences for the physical properties of the polymers.     

Characterization of self-reactive T cells that evade tolerance in hepatitis B e antigen transgenic mice

Previous studies of hepatitis B e antigen (HBeAg)-expressing transgenic (Tg31e) mice have indicated that the degree of T cell tolerance was epitope specific. For example, T cells specific for residues 120–131 of HBeAg are profoundly tolerant, whereas a proportion of T cells specific for residues 129–140 escape tolerance induction in B10. S × B10-Tg31e mice. To understand the basis for differential tolerance towards two T cell sites on the same self antigen, we characterized T cell recognition of HBeAg by primary T cells and T cell hybridomas derived from HBeAg-Tg and non-Tg mice. The self-reactive T cells surviving in B10-Tg31e mice exhibited a unique fine specificity, albeit still focussed on HBeAg residues 129–140, which could be distinguished from the HBeAg-specific T cell repertoire in non-Tg B10 mice. Further, self-reactive T cells were comprised predominantly of Th2-type cells that preferentially evaded tolerance induction as compared to their Th1 counterparts. Because HBeAg may act as a tolerogen during the vertical transmission of chronic hepatitis B virus (HBV) infection, these results suggest that a predominance of HBeAg-specific Th2 cells expressing a limited repertoire may influence the initiation or the maintenance of the HBV chronic carrier state.     

Evaluating Differences in Whole Blood,Serum, and Urine Screening Tests for Zika Virus,Puerto Rico,USA, 2016

We evaluated nucleic acid amplification testing (NAAT) for Zika virus on whole-blood specimens compared with NAAT on serum and urine specimens among asymptomatic pregnant women during the 2015–2016 Puerto Rico Zika outbreak. Using NAAT, more infections were detected in serum and urine than in whole blood specimens.     

Culture and in vitro bromodeoxyuridine-labelling of mouse kidney explants

Summary A method is described for extended mouse renal organ culture and is evaluated for the study of cell proliferation in 1 mm³ explants of renal cortex. Explants were maintained for up to 14 days with cellular viability being sustained at 20% of the original tissue block from day 2. Labelling indices in tuft, capsular and tubular cells ranged from 0 to approximately 20% over the culture period, following in vitro bromodeoxyuridine uptake. This technique offers potential for the study of local effects of inhibitors of proliferation.     

The willingness to continue caring in family supporters of older people

Research has revealed the importance of characteristics of the supporter, the care-recipient, and circumstances of caregiving in the success or failure of community-based care of older people. The Dundee Study of Carers and Dementia examined factors associated with the maintenance and care of older people in the community, and with the impact of dementia on family supporters. Two hundred and twenty-eight family supporters of community-resident older people (≥65) (50% with dementia, 50% without, matched for age and sex) were interviewed. Supporters' responses to their relative's condition and circumstances, their ways of coping with stressful caregiving problems, and their willingness to continue their caregiving role, were assessed. Findings indicated that willingness to care and stress were associated in different ways with the supporter's response to his/her relative. Coping was found to be significantly associated with stress, response to relative, and willingness to care in only three out of a total of 45 tests. Willingness to care was positively associated with the coping behaviour internalization. The findings are discussed in the context of developing interventions for improving the well-being of supporters of an older relative in the community.     

The Cerebral Cortex of the Rat and Visual Attentional Function: Dissociable Effects of Mediofrontal, Cingulate, Anterior Dorsolateral, and Parietal Cortex Lesions on a Five-Choice Serial Reaction Time Task

Dissociable effects of bilateral excitotoxic lesions of differentregions of the rat neocortex, including medial prefrontal andanterior cingulate cortices, were investigated in a five-choiceserial reaction time task that provides several indices of theaccuracy and speed of attentional function. Whereas medial prefrontalcortical lesions impaired performance of the task as revealedby a reduction in choice accuracy, an increase in the latencyto respond correctly to the visual target and enhanced perseverativeresponding, lesions of the anterior cingulate cortex specificallyincreased premature responding. By contrast, lateral frontalcortical lesions did not significantly disrupt baseline performanceof the task, but rather increased the latency to respond correctlyto the visual target during various behavioral manipulations,for example, when the length of the intertrial interval wasvaried unpredictably and during interpolation of distractingbursts of white noise. Lesions of the parietal cortex failedto disrupt any aspect of task performance investigated. These behavioral effects in the five-choice task were comparedwith the effect of these same lesions on acquisition and retentionof a one-trial passive avoidance task. The main finding fromthis paradigm was that lesions of the lateral frontal cortexproduced a significant disruption to the retention of passiveavoidance, which stands in marked contrast to the successfulretention observed by animals of the other lesion groups. Inaddition, this pattern of results reveals that the "disinhibitory"effect of cingulate cortex lesions are relatively specific tothe five-choice attentional task. Finally, the results of the present study are compared withthe findings of previous experiments using the five-choice task,which have examined the effect of selective manipulations ofthe ascending noradrenergic, cholinergic, dopaminergic. andserotonergic projections. In particular, the deficits in attentionalfunction observed following cholinergic lesions of the nucleusbasalis magnocellularis appear to be attributable to cholinergicdenervation of the medial frontal cortex. These results arediscussed in terms of the role of parallel distributed neuralsystems within the neocortex that mediate continuous attentionalperformance in the rat.     

Vascular and electromyographic responses evoked in forearm muscle by isometric contraction of the contralateral forearm

There is controversy over whether isometric contraction of the forearm evokes vasoconstriction or vasodilatation in the muscles of the contralateral forearm. In the present study we have investigated in normal man, the effects of isometric contraction of one arm at 75, 50 and 25% maximum voluntary contraction (MVC) on arterial pressure, heart rate, blood flow and vascular resistance of the contralateral forearm and on electromyographic (EMG) activity recorded from that same arm with sensitive, surface electrodes.When EMG activity was not being recorded from the resting arm, isometric contraction of the contralateral arm for 2 min evoked increases in arterial pressure and heart rate whose magnitudes were graded with % MVC and an increase in forearm blood flow and a decrease in forearm vascular resistance at 75, 50 and 25% MVC, indicating vasodilatation. Further experiments in which EMG activity was recorded from the resting arm demonstrated that the decrease in forearm vascular resistance evoked by 75% MVC was associated with a substantial increase in EMG activity of the extensor and flexor muscles of that arm. By contrast, when forearm contraction was performed at 75% MVC whilst subjects viewed the EMG activity in the resting arm on an oscilloscope and kept EMG activity minimal, vascular resistance increased in that arm, indicating vasoconstriction. Further, when subjects performed contraction at 25% MVC whilst showing minimal EMG activity in the contralateral arm, vascular resistance in that same arm increased (from 78 ± 16 to 124 ± 29 mmHg/ml/min/100 ml tissue). These results are discussed in relation to those of previous studies. We propose, that in normal man, isometric contraction of the forearm evokes primary vasoconstriction in the muscles of the contralateral forearm, but that this response may be overcome by muscle vasodilatation occurring secondary to unintended muscle contraction or as part of the alerting response to acute stress.