bluuebunny/crossref_metadata_2025 huggingface dataset:
Language profiles of monolingual and bilingual Finnish preschool children at risk for language impairment
Authors: Westman Martin , Korkman Marit , Mickos Annika , Byring Roger
Published: May 2008

Background: A large proportion of children are exposed to more than one language, yet research on simultaneous bilingualism has been relatively sparse. Traditionally, there has been concern that bilingualism may aggravate language difficulties of children with language impairment. However, recent studies have not found specific language impairment (SLI) or language‐related problems to be increased by bilingualism.

Aims: The topic of bilingualism and its effects has high actuality in Finland, where increasing numbers of children in the country's 6% Swedish‐speaking minority grow up in bilingual families, where one parent's primary language is Swedish and the other's Finnish. The present study aimed at exploring the influence of such bilingualism on the language profiles of children from this population at risk for language impairment (LI).

Methods & Procedures: Participants were recruited from a language screening of 339 children from kindergartens with instruction only in Swedish, from the Swedish‐speaking parts of Finland. Of these children, 33 (9.7%) were defined as a Risk Group for LI, whereas 48 non‐risk children were randomly selected to form a control group. When subdividing the children according to home language, 35 were found to be monolingual, Swedish‐speaking, and 46 were Swedish–Finnish bilingual. The children underwent neuropsychological assessment during their preschool year. Assessment methods included subtests from the Wechsler Primary and Preschool Scale of Intelligence – Revised and the NEPSY Developmental Neuropsychological Assessment.

Outcomes & Results: A repeated‐measures multiple analysis of covariance (MANCOVA) showed a significant effect of risk of LI on the NEPSY language scores. The effect of home language was not significant and there was no interaction between home language and risk for LI. Non‐verbal IQ was controlled for. Across groups, bilingual children scored lower than monolingual children only on measures of vocabulary and sentence repetition.

Conclusions: Although a slight general cost of bilingualism was found in the language profile of the six‐year olds in this study, a bilingual background was not associated with more severe language problems in the LI Risk Group. Thus, there would seem to be no need to shield language‐impaired children from opportunities for dual language learning.
Increasing prevalence of specific language impairment (SLI) in primary healthcare of a Finnish town, 1989–99
Authors: Hannus Sinikka , Kauppila Timo , Launonen Kaisa
Published: May 2008

Background: The increasing prevalence of specific language impairment (SLI) is a matter of current debate.

Aims: Speech and language therapists and other authorities in Finland have discussed the prevalence of SLI since the 1990s. This discussion has been based on international studies because of the lack of national studies. This paper presents the first Finnish prevalence study of SLI in primary healthcare and, thus, participates in the international discussion on the prevalence of SLI. Furthermore, two samples of delayed language development (DLD) were studied.

Methods & Procedures: This is a retrospective study from 1989–1999. It was conducted on the population of one of the biggest towns in Finland, and was collected from the statistical records of speech and language therapists.

Outcomes & Results: The prevalence of SLI increased, and this increase was statistically significant. The prevalence of SLI was less than 1% in age group 0–6 years and, thus, presents a much lower prevalence than international discussion has suggested. SLI seems to be present particularly in boys though it was also increasing in girls. Furthermore, children with SLI seem to be more affected by receptive difficulties over the period studied. Particularly important is the observation that the prevalence of DLD was also increasing, and together with SLI they suggest a prevalence rate of 2.5% in Finland.

Conclusions: The low prevalence of SLI in this study might be a consequence of the path of intervention that effectively separates SLI from delayed language development. Furthermore, the questions of language specific features needs to be emphasized. The findings of this study suggest that the prevalence of SLI increased as did the prevalence of DLD. The range of prevalence estimates of SLI in different studies raises the need for national and international epidemiological studies of SLI with equal criteria of assessment in each language.
Specific language impairment and school outcomes. I: Identifying and explaining variability at the end of compulsory education
Authors: Conti‐Ramsden Gina , Durkin Kevin , Simkin Zoë , Knox Emma
Published: May 2008

Background: This investigation reports the results of national educational examinations in secondary schooling for young people who have been participating in the Manchester Language Study.

Aims: The emphasis of the study is on furthering understanding of educational outcomes at the end of compulsory education.

Methods & Procedures: A total of 120 adolescents with a history of specific language impairment (SLI) and 121 adolescents with typical development (TD) who were in their final year of compulsory secondary schooling (mean age = 17;4 years) participated. National educational examination results throughout secondary schooling were collected along with a range of psycholinguistic skills from 11 to 16/17 years.

Outcomes & Results: Forty‐four per cent of young people with SLI obtained at least one of the expected qualifications at the end of secondary education, indicating some improvements compared with reports on earlier cohorts. Regression analyses revealed that literacy and language skills were predictive of educational attainment after controlling for IQ and maternal education. Nearly one‐quarter of the sample of adolescents with SLI was not entered for any examinations at the end of compulsory education. A very strong association between earlier patterns of entry for examinations and patterns of examination entry at school leaving age was found.

Conclusions: In addition to performance IQ, concurrent and early literacy and language skills have significant effects on the academic attainments of young people with a history of SLI. The transition from primary to secondary schooling is a crucial time for assessment and evaluation of individual children's needs and levels of support required.
Quality of phonological representations: a window into the lexicon?
Authors: Claessen Mary , Heath Steve , Fletcher Janet , Hogben John , Leitão Suze
Published: May 2008

Background: There is a great deal of evidence to support the robust relationship between phonological awareness and literacy development. Researchers are beginning to understand the relationship between the accuracy and distinctiveness of stored phonological representations and performance on phonological awareness tasks. However, many of the tasks currently used to assess the integrity of underlying representations are confounded by requiring spoken output.

Aims: This paper describes the development of the Quality of Phonological Representations (QPR) task, a task that does not require speech output, and its evaluation in the context of a larger study examining predictors of literacy outcomes in Western Australia.

Methods & Procedures: The QPR task was given as part of a larger task battery to a cohort of 235 mainstream children in the last term of their Preprimary year (average age = 5;5) and to 179 children at follow‐up at the end of Year 2 (average age = 7;9).

Outcomes & Results: Normative data for both accuracy and reaction time are presented in percentile tables (appendix B). In their Preprimary year, children were able to identify correct productions of multi‐syllabic words (hits) on average 87.5% of the time, rising to an average of 93.8% in Year 2. As expected, children became quicker at making these judgements, reaction time shifting from an average of 1.1 s in Preprimary to 0.83 s in Year 2. A similar pattern was observed with the data for correct rejections. To make these judgements, the children had to identify a pseudo‐word as an incorrect pronunciation by ‘Katie the computer’. In the Preprimary year, children were able to reject correctly the pseudo‐words on average 68.5% of the time, rising to an average of 81.7% in Year 2. As expected, children became quicker at making these judgements, reaction time shortening from an average of 1.4 s in Preprimary to 0.81 s in Year 2. The QPR task was shown to have moderate reliability and concurrent validity.

Conclusions: The QPR task appears to be a useful and cost‐effective addition to task batteries aiming to identify at‐risk children in the early stages of schooling. The ability to profile children's phonological awareness skills and gain insight into their underlying phonological representation skills allows more informed goal setting and intervention planning.
Health‐related quality of life in people with severe aphasia
Authors: Hilari Katerina , Byng Sally
Published: May 2008

Background: Health‐related quality of life (HRQL) measures are increasingly used to help us understand the impact of disease or disability on a person's life and to measure the effectiveness of interventions. A small number of studies have looked at perceived HRQL in people with mild or moderate aphasia. They report that reduced HRQL is associated with low psychological well‐being and depression, reduced activity levels and high levels of communication disability. Still, very little is known about the quality of life of people with severe aphasia.

Aims: This study aimed to evaluate the HRQL of people with severe aphasia as rated by their proxy respondents. To increase our understanding of these proxy evaluations, the findings were compared with those of two other studies of HRQL in people with moderate or mild aphasia, using proxy and self‐report respondents.

Methods & Procedures: A questionnaire‐based cross‐sectional survey was carried out where proxies of people with severe aphasia reported on their HRQL. The people with severe aphasia who took part in this study were part of a larger cohort of people with aphasia who were able to self‐report on their HRQL. Aphasia was assessed with the American Speech and Hearing Association Functional Assessment of Communication Skills for Adults (ASHA‐FACS) and the Frenchay Aphasia Screening Test (FAST) and HRQL with the Stroke and Aphasia Quality of Life (SAQOL) scale (proxy‐reported). SAQOL‐39 scores were derived from the SAQOL.

Results & Results: People with severe aphasia's quality of life, as measured by their proxies (n = 12), was low and more than one standard deviation below that of the standardization sample of the SAQOL. The overall mean score for the SAQOL‐39 and the means for its physical and communication domains were below the 20th centile. They were also significantly lower that those of the comparison studies of self‐reports (n = 83) and proxy ratings (n = 50) of people with mild or moderate aphasia (p0.003). In the comparison studies there were no significant differences between the self‐report and proxy ratings of people with mild or moderate aphasia.

Conclusions & Implications: This small study suggests that the HRQL of people with severe aphasia, as reported by their proxies, is severely compromised. Further research, using a wide range of methodologies, is needed in order to address the challenge of understanding better the quality of life of people with severe aphasia.
Evidence for expectancy as a mediator of avoidance and anxiety in a laboratory model of human avoidance learning
Authors: Lovibond Peter F. , Saunders J. Clare , Weidemann Gabrielle , Mitchell Christopher J.
Published: May 2008

A laboratory model was developed to study human avoidance learning. Participants could avoid an electric shock signalled by a 5-s conditioned stimulus (CS) by pressing one of a set of response buttons. Self-reported shock expectancy and skin conductance were recorded during a subsequent 10-s interval before shock. Shock expectancy declined when the correct avoidance response was learned and returned when the response was unavailable. Learning transferred to another shock CS. Parallel effects were observed on skin conductance once performance anxiety was controlled by requiring responding on all trials. Learning was faster when the Pavlovian contingencies were trained before introduction of the instrumental response. The results support a cognitive model of anxiety in which performance of an avoidance response reduces expectancy of an aversive outcome and thereby reduces anxiety.
Effects of timbre and tempo change on memory for music
Authors: Halpern Andrea R. , Müllensiefen Daniel
Published: May 2008

We investigated the effects of different encoding tasks and of manipulations of two supposedly surface parameters of music on implicit and explicit memory for tunes. In two experiments, participants were first asked to either categorize instrument or judge familiarity of 40 unfamiliar short tunes. Subsequently, participants were asked to give explicit and implicit memory ratings for a list of 80 tunes, which included 40 previously heard. Half of the 40 previously heard tunes differed in timbre (Experiment 1) or tempo (Experiment 2) in comparison with the first exposure. A third experiment compared similarity ratings of the tunes that varied in timbre or tempo. Analysis of variance (ANOVA) results suggest first that the encoding task made no difference for either memory mode. Secondly, timbre and tempo change both impaired explicit memory, whereas tempo change additionally made implicit tune recognition worse. Results are discussed in the context of implicit memory for nonsemantic materials and the possible differences in timbre and tempo in musical representations.
Motor limitation in dual-task processing with different effectors
Authors: Bratzke Daniel , Ulrich Rolf , Rolke Bettina , Schröter Hannes , Jentzsch Ines , Leuthold Hartmut
Published: May 2008

According to the extended bottleneck model, dual-task interference does not arise only from a central bottleneck but also from processing limitations at the motor stage. Evidence for this assumption has previously been found only for same-effector tasks but not for different-effector tasks. In order to examine the existence of motor interference with different effectors, we used the psychological refractory period paradigm and employed response sequences of different length in Task 1 (R1 sequence length). Experiment 1 incorporated vocal response sequences in Task 1 and a manual response in Task 2. In Experiment 2, the assignment of the effectors to the two tasks was reversed. In both experiments, the long R1 sequence prolonged reaction time for Task 2 (RT2), and this effect was reduced with decreasing temporal overlap of the two tasks. Thus, the present experiments demonstrate motor interference between different-effector tasks. This interference may be due to on-line programming or to central response monitoring.
Temporal Dynamics of the Action–Sentence Compatibility Effect
Authors: Kaschak Michael P. , Borreggine Kristin L.
Published: May 2008

A number of recent studies have demonstrated variants of the action–sentence compatibility effect (ACE), wherein the execution of a motor response is facilitated by the comprehension of sentences that describe actions taking place in the same direction as the motor response (e.g., a sentence about action towards one's body facilitates the execution of an arm movement towards the body). This paper presents an experiment that explores how the timing of the motor response during the processing of sentences affects the magnitude of the ACE that is observed. The results show that the ACE occurs when the motor response is executed at an early point in the comprehension of the sentence, disappears for a time, and then reappears when the motor response is executed right before the end of the sentence. These data help to refine our understanding of the temporal dynamics involved in the activation and use of motor information during sentence comprehension.
Putting in the mind versus putting on the green: Expertise, performance time, and the linking of imagery and action
Authors: Beilock Sian L. , Gonso Sara
Published: May 2008

Does manipulating the time available to image executing a sensorimotor skill impact subsequent skill execution outcomes in a similar manner as manipulating execution time itself? Novice and skilled golfers performed a series of imaged golf putts followed by a series of actual golf putts under instructions that emphasized either speeded or nonspeeded imaging/putting execution. Novices putted less accurately (i.e., higher putting error score) following either putting or imagery instructions in which speed was stressed. Skilled golfers showed the opposite pattern. Although more time available to execute a skill enhances novice performance, this extra time harms the proceduralized skill of experts. Manipulating either actual execution time or imagined execution time produces this differential impact on novice and skilled performance outcomes. These results are discussed in terms of the functional equivalence between imagery and action and expertise differences in the attentional control structures governing complex sensorimotor skill execution.
Attention and expectation in human predictive learning: The role of uncertainty
Authors: Hogarth Lee , Dickinson Anthony , Austin Alison , Brown Craig , Duka Theodora
Published: May 2008

Three localized, visual pattern stimuli were trained as predictive signals of auditory outcomes. One signal partially predicted an aversive noise in Experiment 1 and a neutral tone in Experiment 2, whereas the other signals consistently predicted either the occurrence or absence of the noise. The expectation of the noise was measured during each signal presentation, and only participants for whom this expectation demonstrated contingency knowledge showed differential attention to the signals. Importantly, when attention was measured by visual fixations, the contingency-aware group attended more to the partially predictive signal than to the consistent predictors in both experiments. This profile of visual attention supports the Pearce and Hall (1980) theory of the role of attention in associative learning.
Reminiscence Bump in Autobiographical Memory: Unexplained by Novelty, Emotionality, Valence, or Importance of Personal Events
Authors: Janssen Steve M. J. , Murre Jaap M. J.
Published: May 2008

People tend to recall a disproportionately large number of personal events from their adolescence and early adulthood. This “reminiscence bump” has been examined extensively, but its causes remain unclear. In this Internet-based experiment, nearly 3,500 participants were given 10 cue words and were asked to describe the personal events that came to mind. Furthermore, they were asked to date each event and to indicate whether it was a first-time experience. Finally, the participants were asked to rate the strength of the emotional reaction to the event or the valence or the importance of the event. Surprisingly, the reminiscence bump consisted of relatively fewer novel, emotional, important positive or negative events. This result increases the likelihood of an alternative explanation—namely, that memory is generally enhanced in adolescence and early adulthood. However, this account has not been tested directly.
Priming of Abstract Letter Identities in the Letter Match Task
Authors: Kinoshita Sachiko , Kaplan Leanne
Published: May 2008

Previous studies of letter recognition have not found priming for abstract letter identities. We used a task that required participants to decide whether a target is the same or different from a reference letter presented in opposite case, which avoids the shortcomings of tasks used in previous studies. We found robust priming effects in this task, which were the same size for letter pairs that have similar visual features across case (e.g., c/C, x/X) and dissimilar features (e.g., a/A, b/B). Also, the pattern of priming was the same whether the prime was in the same or different case as the reference. We take these findings as evidence that abstract letter identities support priming in this task. We suggest that the same–different match task is a useful tool for studying representations used to support masked priming in letter recognition and with other stimuli with limited set size.
Within-Subject Renewal in Sign Tracking
Authors: Rescorla Robert A.
Published: May 2008

Three sign-tracking experiments using pigeon subjects examined the contextual dependence of extinction after conditioning. Renewal of extinguished responding occurred when testing occurred in a different context, using a variety of different renewal designs. In each case, a within-subject design ensured that the various contexts were equivalent in their general treatment histories and differed only in whether or not a particular stimulus had been extinguished in their presence. These results strengthen the view that extinction is relatively context specific.
The varying effects of age of acquisition
Authors: Catling Jonathan C. , Johnston Robert A.
Published: May 2008

There are a number of theories that suggest that age of acquisition (AoA) effects are not uniform across different tasks. Catling and Johnston (2006a) found greater AoA effects within an object-naming task than in a semantic classification task. They explained these findings by suggesting that AoA effects might accumulate according to how many levels of representation a task necessitates access to. Brysbaert and Ghyselinck (2006) explain the difference in AoA effects by proposing two distinct types of AoA (frequency dependent and frequency independent), the first accounted for by a connectionist-type mechanism and the latter situated at the interface between semantics and word production. Moreover, Moore, Smith-Spark, and Valentine (2004) and Holmes and Ellis (2006) have suggested that there are two loci of AoA effects: at the phonological level and somewhere within the perceptual level of representation. Again, this could account for the varying degrees of AoA effects. This study sets about testing these ideas by assessing the effect size of AoA across a series of different tasks that necessitate access to various levels of representation. Experiments 1–4 demonstrate significant effects of AoA in a novel picture–picture verification task, an object classification task, a picture verification task, and an object-naming task. Experiment 5 showed no effects of initial phoneme on the naming of the critical objects used within Experiments 1–4. The implication of the varying AoA effect sizes found within Experiments 1–4 in relation to explanations of AoA are discussed.
Why do people show minimal knowledge updating with task experience: Inferential deficit or experimental artifact?
Authors: Hertzog Christopher , Price Jodi , Burpee Ailis , Frentzel William J. , Feldstein Simeon , Dunlosky John
Published: May 2008

Students generally do not have highly accurate knowledge about strategy effectiveness for learning, such as that imagery is superior to rote repetition. During multiple study–test trials using both strategies, participants’ predictions about performance on List 2 do not markedly differ for the two strategies, even though List 1 recall is substantially greater for imagery. Two experiments evaluated whether such deficits in knowledge updating about the strategy effects were due to an experimental artifact or to inaccurate inferences about the effects the strategies had on recall. Participants studied paired associates on two study–test trials—they were instructed to study half using imagery and half using rote repetition. Metacognitive judgements tapped the quality of inferential processes about the strategy effects during the List 1 test and tapped gains in knowledge about the strategies across lists. One artifactual explanation—noncompliance with strategy instructions—was ruled out, whereas manipulations aimed at supporting the data available to inferential processes improved but did not fully repair knowledge updating.
Partial reinforcement and context switch effects in human predictive learning
Authors: Abad María J. F. , Ramos-álvarez Manuel M. , Rosas Juan M.
Published: May 2008

Human participants were trained in a trial-by-trial contingency judgements task in which they had to predict the probability of an outcome (diarrhoea) following different cues (food names) in different contexts (restaurants). Cue P was paired with the outcome on half of the trials (partial reinforcement), while cue C was paired with the outcome on all the trials (continuous reinforcement), both cues in Context A. Test was conducted in both Context A and a different but equally familiar context (B). Context change decreased judgements to C, but not to P (Experiment 1). This effect was found only in the cue trained in the context where a different cue was partially reinforced (Experiment 2). Context switch effects disappeared when different cues received partial reinforcement in both contexts of training (Experiment 3). The implications of these results for an explanation of context switch effects in terms of ambiguity in the meaning of the cues prompting attention to the context (e.g., Bouton, 1997) are discussed.
Why did I right that? Factors that influence the production of homophone substitution errors
Authors: White Katherine K. , Abrams Lise , Zoller Sarah M. , Gibson Samantha M.
Published: May 2008

Despite considerable research on language production errors involving speech, little research exists in the complementary domain of writing. Two experiments investigated the production of homophone substitution errors, which occur when a contextually appropriate word (e.g., beech) is replaced with its homophone (e.g., beach tree). Participants wrote down auditorily presented sentences containing dominant or subordinate homophones. Homophones were preceded by a lexical prime that overlapped in phonology and orthography (e.g., teacher) or only orthography (e.g., headmaster) with the target homophone. Results showed more substitution errors when the context elicited a subordinate homophone than when it elicited a dominant homophone. Furthermore, both types of primes equivalently increased production of homophone errors relative to control words (e.g., lawyer), suggesting that only orthographic overlap between the prime and target was necessary to influence errors. These results are explained within dual-route models of spelling, which postulate an interaction between lexical and sublexical routes when spelling.
Independent effects of colour on object identification and memory
Authors: Lloyd-Jones Toby J. , Nakabayashi Kazuyo
Published: May 2008

We examined the effects of colour on object identification and memory using a study–test priming procedure with a coloured-object decision task at test (i.e., deciding whether an object is correctly coloured). Objects were selected to have a single associated colour and were either correctly or incorrectly coloured. In addition, object shape and colour were either spatially integrated (i.e., colour fell on the object surface) or spatially separated (i.e., colour formed the background to the object). Transforming the colour of an object from study to test (e.g., from a yellow banana to a purple banana) reduced priming of response times, as compared to when the object was untransformed. This utilization of colour information in object memory was not contingent upon colour falling on the object surface or whether the resulting configuration was of a correctly or incorrectly coloured object. In addition, we observed independent effects of colour on response times, whereby coloured-object decisions were more efficient for correctly than for incorrectly coloured objects but only when colour fell on the object surface. These findings provide evidence for two distinct mechanisms of shape–colour binding in object processing.
Dynamic action in virtual environments: Constraints on the accessibility of action knowledge in children and adults
Authors: Daum Moritz M. , Krist Horst
Published: May 2008

In a series of three experiments, we probed the accessibility of action knowledge in different versions of a virtual environment (VE) with 7-year-old children and adults. Using a PHANToMTM haptic interface, participants performed a virtual throwing task in which they tried to propel a ball from a table to hit a target on the ground. In Experiments 1 and 2, the virtual scene was presented on a computer monitor, and, in Experiment 3, it was projected by using a video projector so that the vertical and horizontal dimensions and the spatial location of the VE corresponded to the real-world dimensions. Results indicate that action knowledge is accessible even in a nonimmersive VE, but also suggest that the need to recalibrate perceptual-motor mappings constrains the accessibility of this kind of intuitive knowledge.
After-effects of goal shifting and response inhibition: A comparison of the stop-change and dual-task paradigms
Authors: Verbruggen Frederick , Logan Gordon D.
Published: May 2008

In the present study, we tested three hypotheses that account for after-effects of response inhibition and goal shifting: the goal-shifting hypothesis, the reaction time (RT) adjustment hypothesis, and the stimulus–goal association hypothesis. To distinguish between the hypotheses, we examined performance in the stop-change paradigm and the dual-task paradigm. In the stop-change paradigm, we found that responding on no-signal trials slowed down when a stop-change signal was presented on the previous trial. Similarly, in the dual-task paradigm, we found that responding on no-signal trials slowed down when a dual-task signal was presented on the previous trial. However, after-effects of unsuccessful inhibition or dual-task performance were observed only when the stimulus of the previous trial was repeated. These results are consistent with stimulus–goal association hypothesis, which assumes that the stimulus is associated with the different task goals on signal trials; when the stimulus is repeated, the tasks goal are retrieved, and interference occurs.
Evidence for Modality-Independent Order Coding in Working Memory
Authors: Depoorter Ann , Vandierendonck André
Published: May 2008

The aim of the present study was to investigate the representation of serial order in working memory, more specifically whether serial order is coded by means of a modality-dependent or a modality-independent order code. This was investigated by means of a series of four experiments based on a dual-task methodology in which one short-term memory task was embedded between the presentation and recall of another short-term memory task. Two aspects were varied in these memory tasks—namely, the modality of the stimulus materials (verbal or visuo-spatial) and the presence of an order component in the task (an order or an item memory task). The results of this study showed impaired primary-task recognition performance when both the primary and the embedded task included an order component, irrespective of the modality of the stimulus materials. If one or both of the tasks did not contain an order component, less interference was found. The results of this study support the existence of a modality-independent order code.
Segmenting the Body into Parts: Evidence from Biases in Tactile Perception
Authors: de Vignemont Frédérique , Majid Asifa , Jola Corinne , Haggard Patrick
Published: May 2008

How do we individuate body parts? Here, we investigated the effect of body segmentation between hand and arm in tactile and visual perception. In a first experiment, we showed that two tactile stimuli felt farther away when they were applied across the wrist than when they were applied within a single body part (palm or forearm), indicating a “category boundary effect”. In the following experiments, we excluded two hypotheses, which attributed tactile segmentation to other, nontactile factors. In Experiment 2, we showed that the boundary effect does not arise from motor cues. The effect was reduced during a motor task involving flexion and extension movements of the wrist joint. Action brings body parts together into functional units, instead of pulling them apart. In Experiments 3 and 4, we showed that the effect does not arise from perceptual cues of visual discontinuities. We did not find any segmentation effect for the visual percept of the body in Experiment 3, nor for a neutral shape in Experiment 4. We suggest that the mental representation of the body is structured in categorical body parts delineated by joints, and that this categorical representation modulates tactile spatial perception.
Mediated Conditioning versus Retrospective Revaluation in Humans: The Influence of Physical and Functional Similarity of Cues
Authors: Liljeholm Mimi , Balleine Bernard W.
Published: May 2008

Two experiments assessed whether similarity between the two elements of a compound would influence the degree of mediated extinction versus recovery from overshadowing in human causal judgements. In both Experiments 1 and 2, we assessed the influence of extinguishing one element of a two-element compound on judgements about the other element. In Experiment 1 we manipulated the physical similarity of the two elements of the compound; in Experiment 2, we used equivalence and distinctiveness pretraining in order to vary their functional similarity. We found that these procedures influenced mediated extinction and recovery from overshadowing as a function of both physical and acquired similarity and distinctiveness, respectively. The implications of these results for previously reported differences between humans and nonprimate animals are discussed.
Age of acquisition's effect on memory for semantically associated word pairs
Authors: Gullick Margaret M. , Juhasz Barbara J.
Published: May 2008

This experiment investigated the effects of age of acquisition (AoA) in memory for associated word pairs in a cued recall task. Participants studied a list of frequency-controlled early- and late-acquired words in semantically related pairs and then were asked to recall the second word of the pair when cued with the first. Reaction time effects were found, showing that a late-acquired cue for an early-acquired target word was responded to significantly faster than other combinations. Additionally, late-acquired target words resulted in significantly more accurate responses. As significant differences were found even when frequency was controlled, the effects must therefore stem from the manipulations of AoA. Given this evidence, the implications for AoA's effects on the organization of semantic memory are explored.
IL-15Rα chaperones IL-15 to stable dendritic cell membrane complexes that activate NK cells via trans presentation
Authors: Mortier Erwan , Woo Tammy , Advincula Rommel , Gozalo Sara , Ma Averil
Published: May 2008

Natural killer (NK) cells are innate immune effectors that mediate rapid responses to viral antigens. Interleukin (IL)-15 and its high affinity IL-15 receptor, IL-15Rα, support NK cell homeostasis in resting animals via a novel trans presentation mechanism. To better understand how IL-15 and IL-15Rα support NK cell activation during immune responses, we have used sensitive assays for detecting native IL-15 and IL-15Rα proteins and developed an assay for detecting complexes of these proteins. We find that IL-15 and IL-15Rα are preassembled in complexes within the endoplasmic reticulum/Golgi of stimulated dendritic cells (DCs) before being released from cells. IL-15Rα is required for IL-15 production by DCs, and IL-15 that emerges onto the cell surface of matured DCs does not bind to neighboring cells expressing IL-15Rα. We also find that soluble IL-15–IL-15Rα complexes are induced during inflammation, but membrane-bound IL-15–IL-15Rα complexes, rather than soluble complexes, support NK cell activation in vitro and in vivo. Finally, we provide in vivo evidence that expression of IL-15Rα specifically on DCs is critical for trans presenting IL-15 and activating NK cells. These studies define an unprecedented cytokine–receptor biosynthetic pathway in which IL-15Rα serves as a chaperone for IL-15, after which membrane-bound IL-15Rα–IL-15 complexes activate NK cells via direct cell–cell contact.
The stream of precursors that colonizes the thymus proceeds selectively through the early T lineage precursor stage of T cell development
Authors: Benz Claudia , Martins Vera C. , Radtke Freddy , Bleul Conrad C.
Published: May 2008

T cell development in the thymus depends on continuous colonization by hematopoietic precursors. Several distinct T cell precursors have been identified, but whether one or several independent precursor cell types maintain thymopoiesis is unclear. We have used thymus transplantation and an inducible lineage-tracing system to identify the intrathymic precursor cells among previously described thymus-homing progenitors that give rise to the T cell lineage in the thymus. Extrathymic precursors were not investigated in these studies. Both approaches show that the stream of T cell lineage precursor cells, when entering the thymus, selectively passes through the early T lineage precursor (ETP) stage. Immigrating precursor cells do not exhibit characteristics of double-negative (DN) 1c, DN1d, or DN1e stages, or of populations containing the common lymphoid precursor 2 (CLP-2) or the thymic equivalent of circulating T cell progenitors (CTPs). It remains possible that an unknown hematopoietic precursor cell or previously described extrathymic precursors with a CLP, CLP-2, or CTP phenotype feed into T cell development by circumventing known intrathymic T cell lineage progenitor cells. However, it is clear that of the known intrathymic precursors, only the ETP population contributes significant numbers of T lineage precursors to T cell development.
Robotically Assisted Beating Heart Totally Endoscopic Coronary Artery Bypass (TECAB). is There a Future?
Authors: Srivastava Sudhir , Gadasalli Suresh , Agusala Madhava , Kolluru Ram , Barrera Reyna , Quismundo Shaune , Srivastava Vishwa , Seshadri-Kreaden Usha
Published: May 2008

Objective

Since the introduction of beating heart totally endoscopic coronary artery bypass (TECAB), approximately 400 patients have undergone the procedure worldwide. Despite satisfactory results and reduced morbidity, the procedure has not gained wide acceptance. This report describes the authors’ experience of beating heart TECAB with robotic assistance and the potential adoption of this technique for the future.

Methods

Between July 2004 and December 2005, 93 patients underwent successful for beating heart TECAB (47 males and 46 females). Mean age was 67.4 + 12.3 years. Fifteen (13.8%) were excluded or converted intraoperatively to thoracotomy for completion of procedure. The procedure was performed through port incisions for the robotic arms and the endostabilizer. Single or bilateral internal thoracic arteries were used as conduits. Anastomoses were done using surgical U-clips. Eighteen (19.4%) patients underwent planned hybrid revascularization. Eighty-four (90.3%) patients underwent computed tomography or conventional angiography.

Results

Details of 93 completed revascularization cases are summarized in the tables. No in-hospital mortality, myocardial infarction, or CVA was noted. Mean operative time was 272.6 + 128.9 minutes (median, 270 minutes). Mean anastomotic time was 13.8 + 3.7 minutes. Mean length of hospital stay was 3.4 + 2.0 days (median, 3 days). At the time of study, 122 of 122 (100%) grafts were found to be patent.

Conclusions

Single- and multivessel beating heart TECAB with or without hybrid revascularization may offer a less invasive approach in a selected group of patients.
Properties of non-structural protein 1 of Semliki Forest virus and its interference with virus replication
Authors: Kiiver Kaja , Tagen Ingrid , Žusinaite Eva , Tamberg Nele , Fazakerley John K. , Merits Andres
Published: May 2008

Semliki Forest virus (SFV) non-structural protein 1 (nsP1) is a major component of the virus replicase complex. It has previously been studied in cells infected with virus or using transient or stable expression systems. To extend these studies, tetracycline-inducible stable cell lines expressing SFV nsP1 or its palmitoylation-negative mutant (nsP16D) were constructed. The levels of protein expression and the subcellular localization of nsP1 in induced cells were similar to those in virus-infected cells. The nsP1 expressed by stable, inducible cell lines or by SFV-infected HEK293 T-REx cells was a stable protein with a half-life of approximately 5 h. In contrast to SFV infection, induction of nsP1 expression had no detectable effect on cellular transcription, translation or viability. Induction of expression of nsP1 or nsP16D interfered with multiplication of SFV, typically resulting in a 5–10-fold reduction in virus yields. This reduction was not due to a decrease in the number of infected cells, indicating that nsP1 expression does not block virus entry or initiation of replication. Expression of nsP1 interfered with virus genomic RNA synthesis and delayed accumulation of viral subgenomic RNA translation products. Expression of nsP1 with a mutation in the palmitoylation site reduced synthesis of genomic and subgenomic RNAs and their products of translation, and this effect did not resolve with time. These results are in agreement with data published previously, suggesting a role for nsP1 in genomic RNA synthesis.
Viral accessory protein X stimulates the assembly of functional Borna disease virus polymerase complexes
Authors: Poenisch Marion , Staeheli Peter , Schneider Urs
Published: May 2008

The Borna disease virus (BDV) proteins X and P are translated from a bicistronic viral mRNA. Here, it was shown that the rescue of recombinant BDV from cDNA was enhanced approximately eightfold if reconstitution of the viral polymerase complex was performed with an expression vector encoding X and P rather than P alone. The results provide evidence that appropriate amounts of X reduce the previously reported high sensitivity of the BDV polymerase to imbalances between the viral proteins N and P. These data indicate that X buffers an unfavourable excess of P, thereby stimulating the assembly of functional BDV polymerase complexes.
Premature expression of the latency-related RNA encoded by bovine herpesvirus type 1 correlates with higher levels of beta interferon RNA expression in productively infected cells
Authors: Perez Sandra , Meyer Florencia , Saira Kazima , Doster Alan , Jones Clinton
Published: May 2008

Bovine herpesvirus type 1 (BHV-1) is an important pathogen that can initiate bovine respiratory disease complex. Like other members of the subfamily Alphaherpesvirinae, BHV-1 establishes latency in sensory neurons. The latency-related (LR) gene expresses a family of alternatively spliced transcripts in infected sensory neurons that have the potential to encode several LR proteins. An LR mutant virus that contains three stop codons near the 5′ terminus of the first open reading frame in the LR gene does not express two LR proteins or reactivate from latency. In addition, the LR mutant virus induces higher levels of apoptosis in trigeminal ganglionic neurons and grows less efficiently in certain tissues of infected calves. In spite of the reduced pathogenesis, the LR mutant virus, wild-type BHV-1 and the LR rescued virus exhibit identical growth properties in cultured bovine cells. In this study, we demonstrated that during early phases of productive infection the LR mutant virus expressed higher levels of LR-RNA relative to the LR rescued virus or wt BHV-1. Bovine kidney cells infected with the LR mutant virus also induced higher levels of beta interferon RNA and interferon response genes. These results suggest that inappropriate expression of LR-RNA, in the absence of LR protein expression, may influence the latency-reactivation cycle and pathogenic potential of BHV-1.
Peripheral blood mononuclear cells represent a reservoir of bovine papillomavirus DNA in sarcoid-affected equines
Authors: Brandt Sabine , Haralambus Rhea , Schoster Angelika , Kirnbauer Reinhard , Stanek Christian
Published: May 2008

Bovine papillomaviruses of types 1 and 2 (BPV-1 and -2) chiefly contribute to equine sarcoid pathogenesis. However, the mode of virus transmission and the presence of latent infections are largely unknown. This study established a PCR protocol allowing detection of ≤10 copies of the BPV-1/-2 genes E5 and L1. Subsequent screening of peripheral blood mononuclear cell (PBMC) DNA derived from horses with and without BPV-1/2-induced skin lesions demonstrated the exclusive presence of E5, but not L1, in PBMCs of BPV-1/2-infected equines. To validate this result, a blind PCR was performed from enciphered PBMC DNA derived from 66 horses, revealing E5 in the PBMCs of three individuals with confirmed sarcoids, whereas the remaining 63 sarcoid-free animals were negative for this gene. L1 could not be detected in any PBMC DNA, suggesting either deletion or interruption of this gene in PBMCs of BPV-1/-2-infected equines. These results support the hypothesis that PBMCs may serve as host cells for BPV-1/-2 DNA and contribute to virus latency.
Purification of viral genome-linked protein VPg from potato virus A-infected plants reveals several post-translationally modified forms of the protein
Authors: Hafrén Anders , Mäkinen Kristiina
Published: May 2008

In order to be able to analyse post-translational modifications and protein interactions of viral genome-linked protein VPg taking place during potato virus A (PVA) infection, an affinity tag-based purification system was developed by inserting a sequence encoding a six-histidine and haemagglutinin (HisHA) tag to the 3′ end of the VPg coding sequence within the infectious cDNA clone of PVA. The engineered virus was fully functional and the HisHA tag-encoding sequence remained stable in the PVA genome throughout the infection process. Purification under denaturing conditions resulted in a protein sample that contained multiple VPg and NIa forms carrying post-translational modifications that altered their isoelectric points. Non-modified tagged VPg (pI 8) was a minor product in the protein sample derived from total leaf proteins, but when the replication-associated membranes were used as starting material, its relative amount increased. Further characterization demonstrated that some of the PVA VPg isoforms were modified by multiple phosphorylation events. Purity of the proteins derived from the native purifications with either of the tags was evaluated. A clearly purer VPg sample was obtained by performing tandem affinity purification utilizing both tags sequentially. NIb, CI and HC-Pro co-purified in an affinity-tagged VPg-dependent manner, indicating that the system was able to isolate protein complexes operating during PVA infection.