bluuebunny/crossref_metadata_2025 huggingface dataset:
Endochondral bone tissue engineering using embryonic stem cells
Authors: Jukes Jojanneke M. , Both Sanne K. , Leusink Anouk , Sterk Lotus M. Th. , van Blitterswijk Clemens A. , de Boer Jan
Published: May 2008

Embryonic stem cells can provide an unlimited supply of pluripotent cells for tissue engineering applications. Bone tissue engineering by directly differentiating ES cells (ESCs) into osteoblasts has been unsuccessful so far. Therefore, we investigated an alternative approach, based on the process of endochondral ossification. A cartilage matrix was formed
in vitro
by mouse ESCs seeded on a scaffold. When these cartilage tissue-engineered constructs (CTECs) were implanted s.c., the cartilage matured, became hypertrophic, calcified, and was ultimately replaced by bone tissue in the course of 21 days. Bone aligning hypertrophic cartilage was observed frequently. Using various chondrogenic differentiation periods
in vitro
, we demonstrated that a cartilage matrix is required for bone formation by ESCs. Chondrogenic differentiation of mesenchymal stem cells and articular chondrocytes showed that a cartilage matrix alone was not sufficient to drive endochondral bone formation. Moreover, when CTECs were implanted orthotopically into critical-size cranial defects in rats, efficient bone formation was observed. We report previously undescribed ESC-based bone tissue engineering under controlled reproducible conditions. Furthermore, our data indicate that ESCs can also be used as a model system to study endochondral bone formation.
Dachshund inhibits oncogene-induced breast cancer cellular migration and invasion through suppression of interleukin-8
Authors: Wu Kongming , Katiyar Sanjay , Li Anping , Liu Manran , Ju Xiaoming , Popov Vladimir M. , Jiao Xuanmao , Lisanti Michael P. , Casola Antonella , Pestell Richard G.
Published: May 2008

Oncogene-mediated signaling to the host environment induces a subset of cytokines and chemokines. TheDrosophila Dacgene promotes migration of the morphogenetic furrow during eye development. Expression of the cell-fate determination factorDachshund(DACH1) was lost in poor prognosis invasive breast cancer. Mouse embryo fibroblasts derived fromDach1−/−mice demonstrated endogenousDach1constitutively represses cellular migration. DACH1 inhibited cellular migration and invasion of oncogene (Ras, Myc, ErbB2, c-Raf)-transformed human breast epithelial cells. An unbiased proteomic analysis identified and immunoneutralizing antibody and reconstitution experiments demonstrated IL-8 is a critical target of DACH1 mediating breast cancer cellular migration and metastasisin vivo. DACH1 bound the endogenousIL-8promoter in ChIP assays and repressed theIL-8promoter through the AP-1 and NF-κB binding sites. Collectively, our data identify a pathway by which an endogenous cell-fate determination factor blocks oncogene-dependent tumor metastasis via a key heterotypic mediator.
A citation analysis of Henri Tajfel's work on intergroup relations
Authors: Dumont Kitty , Louw Johann
Published: May 2008

The late Henri Tajfel (1919–1982) is one of the central figures who shaped the development of post‐war European social psychology. His contributions range from the establishment of an infrastructure for a European social psychology, and the start of a new intellectual movement within social psychology, to the formulation of a set of concepts addressing intergroup relations that were finally integrated into Social Identity Theory. The present study provides an empirical examination of Tajfel's contribution to intergroup research over the last 30 years via a citation analysis of five journals: the Journal of Personality and Social Psychology, the British Journal of Social Psychology, the European Journal of Social Psychology, the South African Journal of Psychology, and the German Journal of Social Psychology (Zeitschrift für Sozialpsychologie). The results indicate that Tajfel's work on intergroup relations is increasingly cited, especially since the 1990s, and the international recognition of his work is substantial. Three possible reasons for the recognition his work still enjoys are proposed: its potential to generate theoretical and empirical controversies; its explanatory power; and the extent to which his work is used as a referential framework.
The adaptation of Chinese adolescents in two societies: A comparison of Chinese adolescents in Hong Kong and Australia
Authors: Leung Cynthia , Karnilowicz Wally
Published: May 2008

This study aimed to compare the adaptation of two groups of migrant Chinese adolescents with their nonmigrant peers. The migrant adolescents included 55 Chinese migrant adolescents who migrated to Australia (Chinese‐Australian) and 111 China‐born adolescents who migrated to Hong Kong (Chinese‐Hong Kong). The nonmigrant adolescents included 157 Anglo‐Australian adolescents residing in Australia and 456 Hong Kong‐born Chinese adolescents residing in Hong Kong. There were three research questions in this study. First, would there be any differences in the adaptation of Chinese migrant adolescents in different societies of settlement? Second, would migrant adolescents experience more adaptation problems than nonmigrant adolescents? Third, would there be any differences in the adaptation of adolescents in the two societies, Australia and Hong Kong? It was hypothesized that: (1) mainland Chinese migrant adolescents in Hong Kong would experience more adaptation problems than Chinese migrant adolescents in Australia; (2) migrant adolescents would report better adaptation than nonmigrant adolescents; (3) adolescents in Hong Kong would report poorer adaptation than adolescents in Australia. The participants were requested to complete a questionnaire on various adaptation outcome measures including life satisfaction, self‐esteem, psychological symptoms, academic satisfaction, and behaviour problems. The results indicated that Chinese‐Australian adolescents reported better psychological adaptation but Chinese‐Hong Kong adolescents reported better sociocultural adaptation. Adolescents resident in Australia reported higher psychological adaptation but lower sociocultural adaptation than those in Hong Kong. Migrant adolescents reported better psychological and sociocultural adaptation than their nonmigrant counterparts. The results were discussed in relation to the social and educational systems of the two societies.
Individual and social dimensions of Filipino students' achievement goals
Authors: Bernardo Allan B. I.
Published: May 2008

Achievement goal theory assumes that self‐instrumental (mastery) achievement goals are associated with academic achievement, whereas social‐instrumental (performance) goals are not. However, research on Asian students shows that both mastery and performance‐approach goals are positively related to achievement; possibly because achievement motivation in Asian cultures is socially oriented and not individually oriented. The current study explored the structure of the social and individual achievement motivation orientations, and how these achievement orientations and achievement goals were related to achievement of Filipino university students. The results showed two dimensions of social‐oriented achievement motivations—parent‐oriented and teacher‐oriented motivations—and two dimensions of individual‐oriented achievement motivations—personal performance standards and personal goal choice. However, these achievement motivation orientations were not associated with achievement. Instead mastery and performance‐approach goals were both positively associated with academic achievement, personal performance standards, and parent‐oriented achievement motivation.
Dialogic or dialectic? The significance of ontological assumptions in research on educational dialogue
Authors: Wegerif Rupert
Published: May 2008

This article explores the relationship between ontological assumptions and studies of educational dialogue through a focus on Bakhtin's ‘dialogic’. The term dialogic is frequently appropriated to a modernist framework of assumptions, in particular the neo‐Vygotskian or sociocultural tradition. However, Vygotsky's theory of education is dialectic, not dialogic. From a dialogic perspective the difference between voices in dialogue is constitutive of meaning in such a way that it makes no sense to imagine ‘overcoming’ this difference. By contrast, due to the implicit assumption that meaning is ultimately grounded on identity rather than upon difference, the dialectic perspective applied by Vygotsky interprets differences as ‘contradictions’ that need to be overcome or transcended. A case study of research on exploratory talk is used to illustrate the potential for a fruitful relationship between ‘high level’ theory and research that is relevant to classroom practice.
The arts, social inclusion and social class: The case of dance
Authors: Sanderson Patricia
Published: May 2008

This article places the results of an empirical research study on the relationship between the social class factor and young people's perceptions of dance within the context of recent British government initiatives promoting social and educational inclusion through the arts. Four Likert‐type dance attitude scales that were developed from pupil opinion expressed during prior discussions were included in a survey questionnaire and responses sought from a nation‐wide representative sample of 1298 11–16‐year‐old boys and girls. Analyses of the data showed that attitudes to aspects of dance varied with social class and that there was an interaction between gender and social class in just one instance. A major implication of the research is that dance and the arts should be more widely available in schools so that all children and young people can have access to aesthetic experiences that have the potential to improve quality of life. It is concluded that the current limited provision within the National Curriculum may be contributing to the social and educational exclusion of some pupils.
Independent reading: The relationship of challenge, non‐fiction and gender to achievement
Authors: Topping K. J. , Samuels J. , Paul T.
Published: May 2008

To explore whether different balances of fiction/non‐fiction reading and challenge might help explain differences in reading achievement between genders, data on 45,670 pupils who independently read over 3 million books were analysed. Moderate (rather than high or low) levels of challenge were positively associated with achievement gain, but non‐fiction read was generally more challenging than fiction. Non‐fiction reading was negatively correlated with successful comprehension and reading achievement gain. Overall, boys appeared to read less than girls, and proportionately more non‐fiction, but this less carefully—especially in the higher grades—and had lower reading achievement. Differences between classrooms in promoting successful comprehension of non‐fiction were evident, suggesting intervention could improve achievement. Implications for research and practice are explored.
Preliminary study of hemodynamic distribution in patient-specific stenotic carotid bifurcation by image-based computational fluid dynamics
Authors: Xue Y.-J. , Gao P.-Y. , Duan Q. , Lin Y. , Dai C.-B.
Published: May 2008

Background: Regions prone to atherosclerosis, such as bends and bifurcations, tend to exhibit a certain degree of non-planarity or curvature, and these geometric features are known to strongly influence local flow patterns. Recently, computational fluid dynamics (CFD) has been used as a means of enhancing understanding of the mechanisms involved in atherosclerotic plaque formation and development.

Purpose: To analyze flow patterns and hemodynamic distribution in stenotic carotid bifurcation in vivo by combining CFD with magnetic resonance angiography (MRA).

Material and Methods: Twenty-one patients with carotid atherosclerosis proved by digital subtraction angiography (DSA) and/or Doppler ultrasound underwent contrast-enhanced MR angiography of the carotid bifurcation by a 3.0T MR scanner. Hemodynamic variables and flow patterns of the carotid bifurcation were calculated and visualized by combining vascular imaging postprocessing with CFD.

Results: In mild stenotic cases, there was much more streamlined flow in the bulbs, with reduced or disappeared areas of weakly turbulent flow. Also, the corresponding areas of low wall shear stress (WSS) were reduced or even disappeared. As the extent of stenosis increased, stronger blood jets formed at the portion of narrowing, and more prominent eddy flows and slow back flows were noted in the lee of the stenosis. Regions of elevated WSS were predicted at the portion of stenosis and in the path of the downstream jet. Areas of low WSS were predicted on the leeward side of the stenosis, corresponding with the location of slowly turbulent flows.

Conclusion: CFD combined with MRA can simulate flow patterns and calculate hemodynamic variables in stenotic carotid bifurcations as well as normal ones. It provides a new method to investigate the relationship of vascular geometry and flow condition with atherosclerotic pathological changes.
High-resolution computed tomography with 16-row mdct: a comparison regarding visibility and motion artifacts of dose-modulated thin slices and “step and shoot” images
Authors: Vikgren J. , Johnsson Å. A. , Flinck A. , Kheddache S. , Milde H. , Båth M.
Published: May 2008

Background: Dose modulation can be used to reduce the radiation dose in computed tomography (CT) examinations while still obtaining the necessary diagnostic image quality. Multidetector-row computed tomography (MDCT) provides the possibility of simultaneous reconstruction of thin and thick slices from the same raw data.

Purpose: To compare thin slices reconstructed from a dose-modulated helical acquisition and conventional high-resolution computed tomography (HRCT) images taken with the “step and shoot” technique in terms of visibility and motion artifacts, in order to investigate the possibility of excluding “step and shoot” acquisition from the HRCT examination.

Material and Methods: Twenty patients were examined by a dose-modulated helical acquisition, “MDCT smart mA,” and by a noncontiguous cross-sectional high-resolution 16-row MDCT examination, “MDCT step and shoot.” Images from four anatomical levels, made anonymous regarding identity and technical data, were analyzed in random order by four thoracic radiologists.

Results: “MDCT smart mA” was worse than “MDCT step and shoot” in terms of visibility. Concerning motion artifacts, “MDCT smart mA” was better than “MDCT step and shoot.”

Conclusion: Thin images reconstructed from a dose-modulated 16-row helical MDCT acquisition (“MDCT smart mA”), as performed in our study, do not provide sufficient image quality regarding visibility compared to the “MDCT step and shoot” technique for the latter technique to be excluded from the HRCT examination.
A diagnostically promising technique for tallying nominal reference errors in the narratives of school‐aged children with Foetal Alcohol Spectrum Disorders (FASD)
Authors: Thorne John C. , Coggins Truman
Published: May 2008

Background: Foetal Alcohol Spectrum Disorders (FASD) include the range of disabilities that occur in children exposed to alcohol during pregnancy, with Foetal Alcohol Syndrome (FAS) on the severe end of the spectrum. Clinical research has documented a range of cognitive, social, and communication deficits in FASD and it indicates the need for diagnostic tools that can identify children with diminished communicative capacities resulting from prenatal alcohol exposure. Previous research indicates that analysis of nominal reference errors within narrative discourse may provide such a tool.

Aims: To demonstrate the potential diagnostic utility of a new tool for tallying nominal reference errors in the oral narratives of school‐aged children with FASD by presenting quantitative measurement data that address interrater agreement and predictive accuracy.

Methods & Procedures: Retrospective analysis was conducted on spontaneously produced oral narratives from 32 school‐aged children (8;5–11;7) with a range of socio‐economic and ethnic profiles. Sixteen of the children had been previously diagnosis with an FASD, including five with full or partial FAS (pFAS). The remaining 16 children were considered typically developing (TD). A range of methods for calculating the rate of nominal reference errors (rNRE) were used to predict which narratives were produced by children from each group. Accuracy (sensitivity and specificity) for two predictions (FASD versus TD, and FAS/pFAS versus all others) was quantified using receiver‐operating characteristic curve analyses. Pairwise statistical comparisons were made between methods to determine which had the most diagnostic potential.

Outcomes & Results: The proposed system for calculating the rNRE was highly accurate at predicting which narratives were produced by children with FASD (versus TD, 88% overall accuracy), and which were produced by children with FAS/pFAS (versus all others, 97% overall accuracy), and outperformed all other methods tested. Agreement on coding decisions between independent judges was high (kappa = 0.90).

Conclusions: The strong predictive accuracy demonstrated in this study provides empirical evidence that the system proposed in this feasibility study has sufficient sensitivity and diagnostic utility to warrant further development for use with children suspected of prenatal alcohol exposure. It also points to the potential for the tool to be used with other clinical populations that, even in the absence of a confirmed alcohol exposure, share many of the communication challenges of this complex clinical population.
Environmental factors that influence communication between people with communication disability and their healthcare providers in hospital: a review of the literature within the International Classification of Functioning, Disability and Health (ICF) framework
Authors: O'Halloran Robyn , Hickson Louise , Worrall Linda
Published: May 2008

The importance of effective healthcare communication between healthcare providers and people needing healthcare is well established. People with communication disabilities are at risk of not being able to communicate effectively with their healthcare providers and this might directly compromise their health, healthcare and their right to participate actively in decisions about their healthcare. This paper reviews the literature on the environmental factors that influence communication between adults with communication disabilities and their healthcare providers in the acute hospital setting within the framework of the World Health Organization's International Classification of Functioning, Disability and Health (ICF) (2001). It focuses in particular on the environmental factors that facilitate or create barriers for people with communication disabilities because environmental factors can be modified so that acute care hospitals can become more accessible communicative environments for all people. The paper describes the particular environmental factors that have been identified in acute hospitals that influence the ability of people with specific types of communication disabilities and their healthcare providers to communicate. It then goes on to describe the common environmental factors that have been identified across people with different types of communication disabilities when they are communicating with their healthcare providers. This paper concludes with suggestions for directions of future research.
The Effects of Superficial and Structural Information on Online Problem Solving for Good versus Poor Anagram Solvers
Authors: Novick Laura R. , Sherman Steven J.
Published: May 2008

The two experiments reported here tested two predictions concerning the sensitivity of good and poor problem solvers to superficial and structural information during online problem solving: (a) Superficial features have a greater effect on solution difficulty for poor problem solvers, whereas (b) structural features have a greater effect on solution difficulty for good problem solvers. The tests were conducted in the domain of anagram solution by manipulating or measuring several superficial and structural characteristics in this domain. The results supported both predictions. They also indicated that better problem solvers have access to structural information from the earliest stages of processing (within the first 2 s). The authors discuss the implications of their results for the types of solution strategies used by more and less competent anagram solvers.
Effect of expertise acquisition on strategic perception: The example of chess
Authors: Ferrari Vincent , Didierjean André , Marmèche Evelyne
Published: May 2008

The two experiments presented here study perceptual processes implemented by chess players in situations related to their domain of expertise. The aim was to determine how patterns are perceived as a function of their strategic value when players acquire expertise. In this study, conducted on novice and more experienced players, it is hypothesized that with acquisition of expertise players would quickly encode familiar patterns and then rapidly focus their attention on patterns with a higher immediate strategic value. In Experiment 1, participants had to carry out a change-detection task that used the “flicker paradigm”. The results showed that during the perception of standard chess positions, experienced players—but not novices—quickly focused their attention on the most strategic patterns. In Experiment 2, experienced players and novices carried out a recognition task after having encoded chess positions for 1 or 5 s. The results indicated early encoding of familiar patterns without immediate strategic value, followed by the encoding of more strategic patterns. Taken together, the results of these two experiments are consistent with the results by both de Groot and Gobet (1996) and McGregor and Howes (2002) about the strategic content of Chase and Simon's chunks (Chase & Simon, 1973b).
Enhanced phonological facilitation and traces of concurrent word form activation in speech production: An object-naming study with multiple distractors
Authors: Abdel Rahman Rasha , Melinger Alissa
Published: May 2008

In the present study, we extended the classic picture–word interference paradigm by the presentation of multiple distractor words (Experiment 1) to reexamine whether the word forms of semantic alternatives receive activation in the course of object naming. Experiment 2 showed that phonological facilitation can be magnified by the presentation of multiple words that share overlapping initial and final segments with the target name. Experiments 3 and 4 tested for traces of nontarget phonological activation with multiple distractors, which enhances the chances of detecting such effects. These experiments revealed a consistent pattern of interference effects induced by words that were related to a semantic category member, consistent with theories assuming phonological activation of nontarget alternatives.
Language-Based Access to Gestural Components of Conceptual Knowledge
Authors: Masson Michael E. J. , Bub Daniel N. , Newton-Taylor Meaghan
Published: May 2008

We report two experiments in which production of articulated hand gestures was used to reveal the nature of gestural knowledge evoked by sentences referring to manipulable objects. Two gesture types were examined: functional gestures (executed when using an object for its intended purpose) and volumetric gestures (used when picking up an object simply to move it). Participants read aloud a sentence that referred to an object but did not mention any form of manual interaction (e.g., Jane forgot the calculator) and were cued after a delay of 300 or 750 ms to produce the functional or volumetric gesture associated with the object, or a gesture that was unrelated to the object. At both cue delays, functional gestures were primed relative to unrelated gestures, but no significant priming was found for volumetric gestures. Our findings elucidate the types of motor representations that are directly linked to the meaning of words referring to manipulable objects in sentences.
What determines auditory similarity? The effect of stimulus group and methodology
Authors: Aldrich Kirsteen M. , Hellier Elizabeth J. , Edworthy Judy
Published: May 2008

Two experiments on the internal representation of auditory stimuli compared the pairwise and grouping methodologies as means of deriving similarity judgements. A total of 45 undergraduate students participated in each experiment, judging the similarity of short auditory stimuli, using one of the methodologies. The experiments support and extend Bonebright's (1996) findings, using a further 60 stimuli. Results from both methodologies highlight the importance of category information and acoustic features, such as root mean square (RMS) power and pitch, in similarity judgements. Results showed that the grouping task is a viable alternative to the pairwise task with N > 20 sounds whilst highlighting subtle differences, such as cluster tightness, between the different task results. The grouping task is more likely to yield category information as underlying similarity judgements.
Reduced orthographic learning in dyslexic adult readers: Evidence from patterns of letter search
Authors: Pitchford Nicola J. , Ledgeway Timothy , Masterson Jackie
Published: May 2008

Visual letter search performance was investigated in a group of dyslexic adult readers using a task that required detection of a cued letter target embedded within a random five-letter string. Compared to a group of skilled readers, dyslexic readers were significantly slower at correctly identifying targets located in the first and second string position, illustrating significantly reduced leftward facilitation than is typically observed. Furthermore, compared to skilled readers, dyslexic readers showed reduced sensitivity to positional letter frequency. They failed to exhibit significantly faster response times to correctly detect target letters appearing in the most, compared to least, frequent letter position within five-letter words, and response times correlated with positional letter frequency only for the initial, and not the final, letter position. These results are compatible with the SERIOL (sequential encoding regulated by inputs to oscillations within letter units) model of orthographic processing proposed by Whitney and Cornelissen (2005). Furthermore, they suggest that dyslexic readers are less efficient than skilled readers at learning to extract statistical regularities from orthographic input.
Evidence for an Expectancy-Based Theory of Avoidance Behaviour
Authors: Declercq Mieke , De Houwer Jan , Baeyens Frank
Published: May 2008

In most studies on avoidance learning, participants receive an aversive unconditioned stimulus after a warning signal is presented, unless the participant performs a particular response. Lovibond (2006) recently proposed a cognitive theory of avoidance learning, according to which avoidance behaviour is a function of both Pavlovian and instrumental conditioning. In line with this theory, we found that avoidance behaviour was based on an integration of acquired knowledge about, on the one hand, the relation between stimuli and, on the other hand, the relation between behaviour and stimuli.
Sequential or parallel decomposed processing of two-digit numbers? Evidence from eye-tracking
Authors: Moeller Korbinian , Fischer Martin H. , Nuerk Hans-Christoph , Willmes Klaus
Published: May 2008

While reaction time data have shown that decomposed processing of two-digit numbers occurs, there is little evidence about how decomposed processing functions. Poltrock and Schwartz (1984) argued that multi-digit numbers are compared in a sequential digit-by-digit fashion starting at the leftmost digit pair. In contrast, Nuerk and Willmes (2005) favoured parallel processing of the digits constituting a number. These models (i.e., sequential decomposition, parallel decomposition) make different predictions regarding the fixation pattern in a two-digit number magnitude comparison task and can therefore be differentiated by eye fixation data. We tested these models by evaluating participants’ eye fixation behaviour while selecting the larger of two numbers. The stimulus set consisted of within-decade comparisons (e.g., 53_57) and between-decade comparisons (e.g., 42_57). The between-decade comparisons were further divided into compatible and incompatible trials (cf. Nuerk, Weger, & Willmes, 2001) and trials with different decade and unit distances. The observed fixation pattern implies that the comparison of two-digit numbers is not executed by sequentially comparing decade and unit digits as proposed by Poltrock and Schwartz (1984) but rather in a decomposed but parallel fashion. Moreover, the present fixation data provide first evidence that digit processing in multi-digit numbers is not a pure bottom-up effect, but is also influenced by top-down factors. Finally, implications for multi-digit number processing beyond the range of two-digit numbers are discussed.
Voluntary and involuntary attention have different consequences: The effect of perceptual difficulty
Authors: Prinzmetal William , Zvinyatskovskiy Aleksey , Gutierrez Paula , Dilem Leo
Published: May 2008

We propose that voluntary and involuntary attention affect different mechanisms and have different consequences for performance measured in reaction time. Voluntary attention enhances the perceptual representation whereas involuntary attention affects the tendency to respond to stimuli in one location or another. In a spatial-cueing paradigm, we manipulated perceptual difficulty and compared voluntary and involuntary attention. For the voluntary-attention condition, the spatial cue was predictive of the target location, whereas in the involuntary-attention condition it was not. Increasing perceptual difficulty increased the attention effect with voluntary attention, but decreased it with involuntary attention. Thus voluntary and involuntary attention have different consequences when perceptual difficulty is manipulated and hence are probably caused by different mechanisms.
An asymmetric effect of relational integration on recognition memory
Authors: Jones Lara L. , Estes Zachary , Marsh Richard L.
Published: May 2008

Two experiments assessed whether conceptual relations (e.g., contains: cookie jar) facilitate the retrieval of concepts (e.g., cookie and jar) from long-term memory. The CARIN model of nominal combination asserts that conceptual relations are represented with and selected from the modifier noun (cookie). Thus, the model predicts that relational integration will facilitate memory for modifiers but not for head nouns (jar). In Experiment 1, concepts were studied in pairs and were then tested individually. Recognition accuracy was higher for modifiers than for head nouns. In Experiment 2, the studied concepts (e.g., cookie jar) were tested in the context of a new pair that instantiated either the same relation (e.g., cookie plate) or a different relation (e.g., cookie crumb). Recognition was again better for modifiers than for head nouns, but only when the same conceptual relation was instantiated at both study and test. Thus, results indicate that conceptual relations (a) facilitate recognition memory, and (b) are associated more strongly with the modifier than with the head noun.
Cross-lingual numerical distance priming with second-language number words in native- to third-language number word translation
Authors: Duyck Wouter , Depestel Isabel , Fias Wim , Reynvoet Bert
Published: May 2008

An important question in research about bilingualism is whether translation from a second language (L2) to the native language (L1) is semantically mediated or whether it occurs through word associations at the lexical level. Recent research has shown that both L1 and L2 number word translation imply semantic access, suggesting strong L2 lexicosemantic mappings for number words (Duyck & Brysbaert, 2004). In the present study, this assumption was further explored by means of a cross-lingual number distance priming paradigm with Dutch–English–French trilinguals. We found that number word translation from L1 to the third language (L3), and vice versa, was facilitated by L2 number masked word primes that represented the same magnitude as the target (translation equivalents), relative to primes that are numerically less close. This confirms the existence of strong L2 lexicosemantic mappings for number words and generalizes previous semantic effects in L1–L2 translation to translation processes between L1 and L3.
Approach and avoidance as action effects
Authors: van Dantzig Saskia , Pecher Diane , Zwaan Rolf A.
Published: May 2008

Numerous studies use arm movements (arm flexion and extension) to investigate the interaction between emotional stimuli and approach/avoidance behaviour. In many experiments, however, these arm movements are ambiguous. Arm flexion can be interpreted either as pulling (approach) or as withdrawing (avoidance). On the contrary, arm extension can be interpreted as reaching (approach) or as pushing (avoidance). This ambiguity can be resolved by regarding approach and avoidance as flexible action plans that are represented in terms of their effects. Approach actions reduce the distance between a stimulus and the self, whereas avoidance actions increase that distance. In this view, action effects are an integral part of the representation of an action. As a result, a neutral action can become an approach or avoidance reaction if it repeatedly results in decreasing or increasing the distance to a valenced stimulus. This hypothesis was tested in the current study. Participants responded to positive and negative words using key-presses. These “neutral” responses (not involving arm flexion or extension) were consistently followed by a stimulus movement toward or away from the participant. Responses to emotional words were faster when the response's effect was congruent with stimulus valence, suggesting that approach/avoidance actions are indeed defined in terms of their outcomes.
The Representation of Negative Numbers: Exploring the Effects of Mode of Processing and Notation
Authors: Tzelgov Joseph , Ganor-Stern Dana , Maymon-Schreiber Keren
Published: May 2008

The representation of negative numbers was explored during intentional processing (i.e., when participants performed a numerical comparison task) and during automatic processing (i.e., when participants performed a physical comparison task). Performance in both cases suggested that negative numbers were not represented as a whole but rather their polarity and numerical magnitudes were represented separately. To explore whether this was due to the fact that polarity and magnitude are marked by two spatially separated symbols, participants were trained to mark polarity by colour. In this case there was still evidence for a separate representation of polarity and magnitude. However, when a different set of stimuli was used to refer to positive and negative numbers, and polarity was not marked separately, participants were able to represent polarity and magnitude together when numerical processing was performed intentionally but not when it was conducted automatically. These results suggest that notation is only partly responsible for the components representation of negative numbers and that the concept of negative numbers can be grasped only through that of positive numbers.
Discerning static and causal interactions in genome-wide reverse engineering problems
Authors: Zampieri Mattia , Soranzo Nicola , Altafini Claudio
Published: May 2008

Background: In the past years devising methods for discovering gene regulatory mechanisms at a genome-wide level has become a fundamental topic in the field of systems biology. The aim is to infer gene-gene interactions in an increasingly sophisticated and reliable way through the continuous improvement of reverse engineering algorithms exploiting microarray data.

Motivation: This work is inspired by the several studies suggesting that coexpression is mostly related to ‘static’ stable binding relationships, like belonging to the same protein complex, rather than other types of interactions more of a ‘causal’ and transient nature (e.g. transcription factor–binding site interactions). The aim of this work is to verify if direct or conditional network inference algorithms (e.g. Pearson correlation for the former, partial Pearson correlation for the latter) are indeed useful in discerning static from causal dependencies in artificial and real gene networks (derived from Escherichia coli and Saccharomyces cerevisiae).

Results: Even in the regime of weak inference power we have to work in, our analysis confirms the differences in the performances of the algorithms: direct methods are more robust in detecting stable interactions, conditional ones are better for causal interactions especially in presence of combinatorial transcriptional regulation.

Contact:  altafini@sissa.it

Supplementary information:  Supplementary data are available at Bioinformatics online.
Evolutionary design principles of modules that control cellular differentiation: consequences for hysteresis and multistationarity
Authors: Kim Junil , Kim Tae-Geon , Jung Sung Hoon , Kim Jeong-Rae , Park Taesung , Heslop-Harrison Pat , Cho Kwang-Hyun
Published: May 2008

Motivation: Gene regulatory networks (GRNs) govern cellular differentiation processes and enable construction of multicellular organisms from single cells. Although such networks are complex, there must be evolutionary design principles that shape the network to its present form, gaining complexity from simple modules.

Results: To isolate particular design principles, we have computationally evolved random regulatory networks with a preference to result either in hysteresis (switching threshold depending on current state), or in multistationarity (having multiple steady states), two commonly observed dynamical features of GRNs related to differentiation processes. We have analyzed the resulting evolved networks and compared their structures and characteristics with real GRNs reported from experiments.

Conclusion: We found that the artificially evolved networks have particular topologies and it was notable that these topologies share important features and similarities with the real GRNs, particularly in contrasting properties of positive and negative feedback loops. We conclude that the structures of real GRNs are consistent with selection to favor one or other of the dynamical features of multistationarity or hysteresis.

Contact:  ckh@kaist.ac.kr

Supplementary information:  Supplementary data are available at Bioinformatics online.
Cuckoo–hawk mimicry? An experimental test
Authors: Davies N.B , Welbergen J.A
Published: May 2008

The similarity between many Old World parasitic cuckoos (Cuculinae) and
Accipiter
hawks, in size, shape and plumage, has been noted since ancient times. In particular, hawk-like underpart barring is more prevalent in parasitic than in non-parasitic cuckoos. Cuckoo–hawk resemblance may reflect convergent evolution of cryptic plumage that reduces detection by hosts and prey, or evolved mimicry of hawks by parasitic cuckoos, either for protection against hawk attacks or to facilitate brood parasitism by influencing host behaviour. Here, we provide the first evidence that some small birds respond to common cuckoos
Cuculus canorus
as if they were sparrowhawks
Accipiter nisus
. Great tits and blue tits were equally alarmed and reduced attendance at feeders during and after the presentation of mounted specimens of common cuckoos and sparrowhawks, but not in response to control presentations of collared doves or teal. Plumage manipulations revealed that the strong alarm response to cuckoos depended on their resemblance to hawks; cuckoos with barred underparts were treated like hawks, while those with unbarred underparts were treated like doves. However, barring was not the only feature inducing alarm because tits showed similarly strong alarm to barred and unbarred hawks, and little alarm to barred doves. These responses of tits, unsuitable as hosts and hence with no history of cuckoo parasitism, suggest that naive small birds can mistake cuckoos for hawks. Thus, any cuckoo–hawk discrimination by host species is likely to be an evolved response to brood parasitism.
Why are programmes for offenders with personality disorder not informed by the relevant scientific findings?
Authors: Duggan Conor
Published: May 2008

This paper examines the evidence to justify intervening in those with personality disorder, specifically antisocial personality disorder (ASPD) as defined by the
Diagnostic and Statistical Manual of Mental Disorders
(DSM-IV, American Psychiatric Association 1994). The evidence from randomized controlled trials in the mental health literature is reviewed and found to be deficient with only five trials satisfying Cochrane criteria, all of which had a reduction in substance misuse as their primary outcome, rather than a change in the personality disorder
per se
.

Next, I consider the contribution of Thomas Kuhn to explain why it is difficult to develop a scientific basis in forensic mental health. I argue that, because forensic mental health is inclusive in its purpose (interacting with the law, social services and the penal system, all of which have different rules and agendas), it is difficult to develop a consensus on fundamentals, this consensus being a hallmark of a science.

Finally, I argue that despite the absence of evidence from mental health, providers for ASPD are in a fortunate position in being able to draw upon the correctional literature. This is relevant, provided that we agree that a reduction in offending is the primary outcome. While mental health can learn much from correctional practice, it can also enhance the efficacy of the latter by, for instance, drawing attention to the specific vulnerabilities of the personality structure that might impede programme delivery in correctional settings. Means of achieving a conjunction of mental health and correctional practice are urgently required as this would be beneficial to both.
Understanding development and prevention of chronic physical aggression: towards experimental epigenetic studies
Authors: Tremblay Richard E
Published: May 2008

The aim of this paper was to highlight how developmental psychopathology, epigenetics and prevention experiments are starting to blend together to explain the developmental causes of chronic physical aggression (CPA) and, more importantly, to help prevent CPA and its associated physical, mental and social problems. After defining the keywords (prevention, chronic and physical aggression), a selected review of published studies is used to answer the following four questions: when should we attempt to prevent onset of CPA? What are the risk factors for CPA? Have early childhood interventions been shown to prevent CPA? Can early preventive interventions benefit from epigenetic studies? The last section of this paper gives two examples of experimental prevention designs that integrate present knowledge of CPA development, risk factors, early childhood preventive interventions and epigenetic programming of brain development during pregnancy and early childhood. I conclude that randomized control trials of preventive interventions during pregnancy and early childhood with a specific focus on epigenetic effects are the research design most likely to advance our understanding of the biopsychosocial mechanisms that lead to CPA, and the only research design that can identify effective interventions for preventing the development of CPA.
Effect of intraventricular infusion of anti-prion protein monoclonal antibodies on disease progression in prion-infected mice
Authors: Song Chang-Hyun , Furuoka Hidefumi , Kim Chan-Lan , Ogino Michiko , Suzuki Akio , Hasebe Rie , Horiuchi Motohiro
Published: May 2008

It is well known that anti-prion protein (PrP) monoclonal antibodies (mAbs) inhibit abnormal isoform PrP (PrPSc) formation in cell culture. Additionally, passive immunization of anti-PrP mAbs protects the animals from prion infection via peripheral challenge when mAbs are administered simultaneously or soon after prion inoculation. Thus, anti-PrP mAbs are candidates for the treatment of prion diseases. However, the effects of mAbs on disease progression in the middle and late stages of the disease remain unclear. This study carried out intraventricular infusion of mAbs into prion-infected mice before and after clinical onset to assess their ability to delay disease progression. A 4-week infusion of anti-PrP mAbs initiated at 120 days post-inoculation (p.i.), which is just after clinical onset, reduced PrPSc levels to 70–80 % of those found in mice treated with a negative-control mAb. Spongiform changes, microglial activation and astrogliosis in the hippocampus and thalamus appeared milder in mice treated with anti-PrP mAbs than in those treated with a negative-control mAb. Treatment with anti-PrP mAb prolonged the survival of mice infected with Chandler or Obihiro strain when infusion was initiated at 60 days p.i., at which point PrPSc is detectable in the brain. In contrast, infusion initiated after clinical onset prolonged the survival time by about 8 % only in mice infected with the Chandler strain. Although the effects on survival varied for different prion strains, the anti-PrP mAb could partly prevent disease progression, even after clinical onset, suggesting immunotherapy as a candidate for treatment of prion diseases.
Safety and immunogenicity of myxoma virus as a new viral vector for small ruminants
Authors: Pignolet Béatrice , Boullier Séverine , Gelfi Jacqueline , Bozzetti Marjorie , Russo Pierre , Foulon Eliane , Meyer Gilles , Delverdier Maxence , Foucras Gilles , Bertagnoli Stéphane
Published: May 2008

Myxoma virus (MYXV), a leporide-specific poxvirus, represents an attractive candidate for the generation of safe and non-replicative vaccine vectors for other species. With the aim of developing new recombinant vaccines for ruminants, we evaluated the safety and the immunogenicity of recombinant MYXV in sheep. In vitro studies indicated that ovine primary fibroblasts were not permissive for MYXV and that infection of ovine peripheral blood mononuclear cells occurred at a low rate. Although non-specific activation significantly improved the susceptibility of lymphocytes, MYXV infection remained abortive. Histological and immunohistochemical examination at the inoculation sites revealed the development of an inflammatory process and allowed the detection of sparse infected cells in the dermis. In addition, inoculated sheep developed an antibody response directed against MYXV and the product of the transgene. Overall, these results provide the first line of evidence on the potential of MYXV as a viral vector for ruminants.