Snakes and kittens in the grass: No evidence for preferential processing of fear-relevant animals in visual search

Ohman and colleagues provided evidence for preferential processing of pictures depicting fear-relevant animals by showing that pictures of snakes and spiders are found faster among pictures of fiowers and mushrooms than vice versa and that the speed of detecting fear-relevant animals was not affected by set size whereas the speed of detecting fiowers/mushrooms was. Experiment 1 replicated this finding. Experiment 2, however, found similar search advantages when pictures of cats and horses or of wolves and big cats were to be found among pictures of flowers and mushrooms. Moreover, Experiment 3, in a within subject comparison, failed to find faster identification of snakes and spiders than of cats and horses among flowers and mushrooms. The present findings seem to indicate that previous reports of preferential processing of pictures of snakes and spiders in a visual search task may reflect a processing advantage for animal pictures in general rather than fear-relevance.

Why fear snakes and spiders? Evidence for a learning-based account of fear-relevant stimulus-processing

Fear-relevant stimuli, such as snakes, spiders and heights, preferentially capture attention as compared to nonfear-relevant stimuli. This is said to reflect an encapsulated mechanism whereby attention is captured by the simple perceptual features of stimuli that have evolutionary significance. Research, using pictures of snakes and spiders, has found some support for this account; however, participants may have had prior fear of snakes and spiders that influenced results. The current research compared responses of snake and spider experts who had little fear of snakes and spiders, and control participants across a series of affective priming and visual search tasks. Experts discriminated between dangerous and nondangerous snakes and spiders, and expert responses to pictures of nondangerous snakes and spiders differed from those of control participants. The current results dispute that stimulus fear relevance is based purely on perceptual features, and provides support for the role of learning and experience.

Individual differences in motivated social cognition: The case of self-serving information processing

Three experiments examined the hypothesis that people show consistency in motivated social cognitive processing across self-serving domains. Consistent with this hypothesis, Experiment 1 revealed that people who rated a task at which they succeeded as more important than a task at which they failed also cheated on a series of math problems, but only when they could rationalize their cheating as unintentional. Experiment 2 replicated this finding and demonstrated that a self-report measure of self-deception did not predict this rationalized cheating. Experiment 3 replicated Experiments 1 and 2 and ruled out several alternative explanations. These experiments suggest that people who show motivated processing in ego-protective domains also show motivated processing in extrinsic domains. These experiments also introduce a new measurement procedure for differentiating between intentional versus rationalized cheating.

Visuospatial processing and the function of prefrontal-parietal networks in autism spectrum disorders: a functional MRI study

Objective: Individuals with autism spectrum disorders typically have normal visuospatial abilities but impaired executive functioning, particularly in abilities related to working memory and attention. The aim of this study was to elucidate the functioning of frontoparietal networks underlying spatial working memory processes during mental rotation in persons with autism spectrum disorders. Method: Seven adolescent males with normal IQ with an autism spectrum disorder and nine age- and IQ-matched male comparison subjects underwent functional magnetic resonance imaging scans while performing a mental rotation task. Results: The autism spectrum disorders group showed less activation in lateral and medial premotor cortex, dorsolateral prefrontal cortex, anterior cingulate gyrus, and caudate nucleus. Conclusions: The finding of less activation in prefrontal regions but not in parietal regions supports a model of dysfunction of frontostriatal networks in autism spectrum disorders.

Centrifugal processing of cell debris and inclusion bodies from recombinant Escherichia coli

The settling characteristics of cell debris and inclusion bodies prior to, and following, fractionation in a disc-stack centrifuge were measured using Cumulative Sedimentation Analysis (CSA) and Centrifugal Disc photosedimentation (CDS). The impact of centrifuge feedrate and repeated homogenisation on both cell debris and inclusion body collection efficiency was investigated. Increasing the normalised centrifuge feedrate (Q/Sigma) from 1.32 x 10(-9) m s(-1) to 3.97 x 10(-9) m s(-1) leads to a 36% increase in inclusion body paste purity. Purity may also be improved by repeated homogenisation. Increasing the number of homogeniser passes results in smaller cell debris size whilst leaves inclusion body size unaltered. At a normalised centrifuge feedrate of 2.65 x 10(-9) m s(-1), increasing the number of homogeniser passes from two (2) to ten (10) improved overall inclusion body paste purity by 58%. Grade-efficiency curves for both the cell debris and inclusion bodies have also been generated in this study. The data are described using an equation developed by Mannweiler (1989) with parameters of k = 0.15-0.26 and n = 2.5-2.6 for inclusion bodies, and k = 0.12-0.14 and n = 2.0-2.2 for cell debris. This is the first accurate experimentally-determined grade efficiency curve for cell debris. Previous studies have simply estimated debris grade efficiency curves using an approximate debris size distribution and grade efficiency curves determined with 'ideal particles' (e.g. spherical PVA particles). The findings of this study may be used to simulate and optimise the centrifugal fractionation of inclusion bodies from cell debris.

Mild head injury and speed of information processing: A prospective study of professional rugby league players

The sensitivity of several short tests of speed of information processing to the effects of mild head injury in rugby league football was investigated. The measures used were the Symbol Digit Modalities Test, the Digit Symbol Substitution Test, and the Speed of Comprehension Test. Two studies were conducted, the first to examine the effect of practice, the second to determine sensitivity to cognitive impairment immediately following injury. The first study established alternate form equivalence and demonstrated that performance on the Speed of Comprehension and Digit Symbol Substitution tests improved with practice, whereas the Symbol Digit Modalities test remained stable. A second study of 10 players who subsequently sustained mild head injuries showed that measures of speed of information processing were sensitive to impairment in the postacute phase, whereas an untimed task of word recognition (Spot-the-Word) was not. Speed of Comprehension was more sensitive to postinjury impairment than either the Digit Symbol Substitution or Symbol Digit Modalities tests. A repeated baseline assessment before injury using the higher score to reflect a player's potential, allowed measurement of impaired performance on sensitive tests.

Conformational dynamics of thyroid hormones by variable temperature nuclear magnetic resonance: The role of side chain rotations and cisoid/transoid interconversions

H-1 NMR spectra of the thyroid hormone thyroxine recorded at low temperature and high field show splitting into two peaks of the resonance due to the H2,6 protons of the inner (tyrosyl) ring. A single resonance is observed in 600 MHz spectra at temperatures above 185 K. An analysis of the line shape as a function of temperature shows that the coalescence phenomenon is due to an exchange process with a barrier of 37 kJ mol(-1). This is identical to the barrier for coalescence of the H2',6' protons of the outer (phenolic) ring reported previously for the thyroid hormones and their analogues. It is proposed that the separate peaks at low temperature are due to resonances for H2,6 in cisoid and transoid conformers which are populated in approximately equal populations. These two peaks are averaged resonances for the individual H2 and H6 protons. Conversion of cisoid to transoid forms can occur via rotation of either the alanyl side chain or the outer ring, from one face of the inner ring to the other. It is proposed that the latter process is the one responsible for the observed coalescence phenomenon. The barrier to rotation of the alanyl side chain is greater than or equal to 37 kJ mol(-1), which is significantly larger than has previously been reported for Csp(2)-Csp(3) bonds in other Ph-CH2-X systems. The recent crystal structure of a hormone agonist bound to the ligand-binding domain of the rat thyroid hormone receptor (Wagner et al. Nature 1995, 378, 690-697) shows the transoid form to be the bound conformation. The significant energy barrier to cisoid/transoid interconversion determined in the current study combined with the tight fit of the hormone to its receptor suggests that interconversion between the forms cannot occur at the receptor site but that selection for the preferred bound form occurs from the 50% population of the transoid form in solution.

Enhancing the phonological processing skills of children with specific reading disability

The present study evaluated the benefits of phonological processing skills training for children with persistent reading difficulties. Children aged between 9-14 years, identified as having a specific reading disability, participated in the study. In a series of three experiments, pedagogical issues related to length of training time, model of intervention and severity of readers' phonological processing skills deficit prior to intervention, were explored. The results indicated that improvement in poor readers' phonological processing skills led to a dramatic improvement in their reading accuracy and reading comprehension performance. Increasing the length of training time significantly improved transfer effects to the reading process. Children with particularly severe phonological processing skill deficits benefited from art extended training period, and both individual and group intervention models for phonological processing training proved successful. Implications for speech and language therapists are discussed.

Immunohistochemistry and polymerase chain reaction on paraffin-embedded material improve the diagnosis of cutaneous leishmaniasis in the Amazon region

Background Recently, there has been an increase in the incidence of cutaneous leishmaniasis (CL), which represents an important health problem. This increase may be related to the epidemiologic expansion of the infective agent and the increase in tourism in tropical areas. The difficulty in clinical diagnosis, mainly in areas in which CL is not the first consideration of local physicians, has intensified efforts to describe diagnostic tests, which should be specific, sensitive, and practical. Amongst the new tests described are those including nucleic acid amplification (polymerase chain reaction, PCR) and immunohistochemistry (IHC). Methods In this study, we evaluated the sensitivity of a PCR based on small subunit (SSU) ribosomal DNA, in comparison with IHC using Leishmania spp. antibodies, in biopsies embedded in paraffin. Result The results indicated a total sensitivity of 96% (90.9% with PCR and 68.8% with IHC), showing the possibility of using paraffin-embedded biopsies to diagnose CL. Conclusion We propose the use of the two tests together as a routine protocol for diagnosis. This would require the provision of local medical services to perform molecular biology techniques and adequate Leishmania antibodies.

Usefulness of qualitative polymerase chain reaction for Trypanosoma cruzi DNA in endomyocardial biopsy specimens of chagasic heart transplant patients

BACKGROUND: Chagas` disease reactivation (CDR) after heart transplantation is characterized by relapse of the infectious disease, with direct detection of Trypanosoma cruzi parasites in blood, cerebrospinal fluid, or tissues. CDR affecting the myocardium induces lymphocytic myocarditis and should be distinguished from acute cellular rejection in endomyocardial biopsy (EMB) specimens. METHODS: We performed retrospectively qualitative polymerase chain reaction for T cruzi DNA using 2 sets of primers targeting nuclear DNA (nDNA) or kinetoplast DNA (kDNA) in 61 EMB specimens of 11 chagasic heart transplant recipients who presented with CDR. Thirty-five EMB specimens were obtained up to 6 months before (pre-CDR group) and 26 up to 2 years after the diagnosis of CDR. The control group consisted of 6 chagasic heart transplant recipients with 18 EMB specimens who never experienced CDR. RESULTS: Amplification of kDNA occurred in 8 of 35 (22.9%) EMB specimens of the pre-CDR group, in 5 of 18(27.8%) of the control group, and in 17 of 26(65.4%) EMB specimens obtained after the successful treatment of CDR. Amplification of nDNA occurred in 3 of 35 (8.6%) EMB specimens of the pre-CDR group, 0 of 18 (0%) of the control group, and 6 of 26 (23.1%) EMB specimens obtained after the successful treatment of CDR. CONCLUSIONS: Amplification of kDNA in EMB specimens is not specific for the diagnosis of CDR, occurring also in patients with no evidence of CDR (control group). However, amplification of nDNA occurred in a few EMB specimens obtained before CDR, but in none of the control group specimens. Qualitative PCR for T cruzi DNA in EMB specimens should not be used as a criterion for cure of CDR because it can persist positive despite favorable clinical evolution of the patients. J Heart Lung Transplant 2011;30:799-804 (C) 2011 International Society for Heart and Lung Transplantation. All rights reserved.

Dual candidemia detected by nested polymerase chain reaction in two critically ill children

The use of improved microbiological procedures associated with molecular techniques has increased the identification of Candida bloodstream infections, even if the isolation of more than one species by culture methods remains uncommon. We report the cases of two children presenting with severe gastrointestinal disorders and other risk factors that contribute to Candida infections. In the first patient, C. albicans DNA was initially detected by a nested-amplification and C. tropicalis was found later during hospitalization, while blood cultures were persistently negative. In the second child, there was amplification of C. albicans and C. glabrata DNA in the same samples, but blood cultures yielded only C. albicans. Both patients received antifungal therapy but had unfavorable outcomes. These two cases illustrate that PCR was more successful than culture methods in detecting Candida in the bloodstream of high risk children, and was also able to detect the presence of more than one species in the same patient that might impact therapy when the fungi are resistant to azole compounds.