bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of the basal ganglia in switching a planned response
Authors: Cameron Ian G. M. , Coe Brian C. , Watanabe Masayuki , Stroman Patrick W. , Munoz Douglas P. 
Published: June 2009

AbstractThe ability to perform an appropriate response in the presence of competing alternatives is a critical facet of human behavioral control. This is especially important if a response is prepared for execution but then has to be changed suddenly. A popular hypothesis of basal ganglia (BG) function suggests that its direct and indirect pathways could provide a neural mechanism to rapidly switch from one planned response to an alternative. However, if one response is more dominant or ‘automatic’ than the other, the BG might have a different role depending on switch direction. We built upon the pro‐ and antisaccade tasks, two models of automatic and voluntary behavior, respectively, and investigated whether the BG are important for switching any planned response in general, or if they are more important for switching from a more automatic response to a response that is more difficult to perform. Subjects prepared either a pro‐ or antisaccade but then had to switch it unexpectedly on a subset of trials. The results revealed increased striatal activation for switching from a pro‐ to an antisaccade but this did not occur for switching from an anti‐ to a prosaccade. This activation pattern depended on the relative difficulty in switching, and it was distinct from frontal eye fields, an area shown to be more active for antisaccade trials than for prosaccade trials. This suggests that the BG are important for compensating for differences in response difficulty, facilitating the rapid switching of one response for another.
In‐vitroanalysis of Pitx3 in mesodiencephalic dopaminergic neuron maturation
Authors: Papanikolaou Theodora , Amano Tomokazu , Lennington Jessica , Sink Kelly , Farrar Andrew M. , Salamone John , Yang Xiangzhong , Conover Joanne C. 
Published: June 2009

AbstractThe transcription factor Pitx3 is expressed exclusively by mesodiencephalic dopaminergic neurons; however, ablation of Pitx3 results in selective degeneration of primarily dopaminergic neurons of the substantia nigra pars compacta, the neuronal population that is most vulnerable in Parkinson’s disease. Although the exact molecular mechanisms of the action of Pitx3 are unclear, roles in both terminal maturation and/or survival of substantia nigra dopaminergic neurons have been suggested. To investigate the connection between Pitx3 and selective neurodegeneration, we generated embryonic stem cells from a Pitx3‐deficient mouse (aphakia) forin‐vitrodifferentiation to dopaminergic neurons. This ‘loss of function’in‐vitrosystem allowed us to examine characteristic features in dopaminergic neuron development and to assess the role that Pitx3 plays in the differentiation/maturation process. We found thataphakiaembryonic stem cells generated 50% fewer tyrosine hydroxylase‐positive/microtubule‐associated protein (Map)2‐positive mature neurons compared with control cultures. The expression of dopamine transport regulators and vesicle release proteins was reduced and dopamine release was unregulated in the Pitx3‐deficient tyrosine hydroxylase‐positive neurons generated. Treatment ofaphakiaembryonic stem cell cultures with retinoic acid resulted in a significant increase in mesodiencephalic tyrosine hydroxylase‐positive neurons, providing further support for the role of Pitx3 in dopaminergic neuron specification through the retinoic acid pathway. Our study, using Pitx3‐deficient embryonic stem cells in anin‐vitrodifferentiation culture system, allowed us to assess the role of Pitx3 in the specification and final maturation of dopaminergic neurons.
Extensive carbon isotopic heterogeneity among methane seep microbiota
Authors: House Christopher H. , Orphan Victoria J. , Turk Kendra A. , Thomas Burt , Pernthaler Annelie , Vrentas Jennifer M. , Joye Samantha B. 
Published: June 2009

SummaryTo assess and study the heterogeneity of δ13C values for seep microorganisms of the Eel River Basin, we studied two principally different sample sets: sediments from push cores and artificial surfaces colonized over a 14 month in situ incubation. In a single sediment core, the δ13C compositions of methane seep‐associated microorganisms were measured and the relative activity of several metabolisms was determined using radiotracers. We observed a large range of archaeal δ13C values (> 50‰) in this microbial community. The δ13C of ANME‐1 rods ranged from −24‰ to −87‰. The δ13C of ANME‐2 sarcina ranged from −18‰ to −75‰. Initial measurements of shell aggregates were as heavy as −19.5‰ with none observed to be lighter than −57‰. Subsequent measurements on shell aggregates trended lighter reaching values as 13C‐depleted as −73‰. The observed isotopic trends found for mixed aggregates were similar to those found for shell aggregates in that the initial measurements were often enriched and the subsequent analyses were more 13C‐depleted (with values as light as −56‰). The isotopic heterogeneity and trends observed within taxonomic groups suggest that ANME‐1 and ANME‐2 sarcina are capable of both methanogenesis and methanotrophy. In situ microbial growth was investigated by incubating a series of slides and silicon (Si) wafers for 14 months in seep sediment. The experiment showed ubiquitous growth of bacterial filaments (mean δ13C = −38 ± 3‰), suggesting that this bacterial morphotype was capable of rapid colonization and growth.
Comparative genomics of marine cyanomyoviruses reveals the widespread occurrence of Synechococcus host genes localized to a hyperplastic region: implications for mechanisms of cyanophage evolution
Authors: Millard Andrew D. , Zwirglmaier Katrin , Downey Mike J. , Mann Nicholas H. , Scanlan Dave J. 
Published: June 2009

SummaryThe vast majority of cyanophages isolated to date are cyanomyoviruses, a group related to bacteriophage T4. Comparative genome analysis of five cyanomyoviruses, including a newly sequenced cyanophage S‐RSM4, revealed a ‘core genome’ of 64 genes, the majority of which are also found in other T4‐like phages. Subsequent comparative genomic hybridization analysis using a pilot microarray showed that a number of ‘host’ genes are widespread in cyanomyovirus isolates. Furthermore, a hyperplastic region was identified between genes g15–g18, within a highly conserved structural gene module, which contained a variable number of inserted genes that lacked conservation in gene order. Several of these inserted genes were host‐like and included ptoX, gnd, zwf and petE encoding plastoquinol terminal oxidase, 6‐phosphogluconate dehydrogenase, glucose 6‐phosphate dehydrogenase and plastocyanin respectively. Phylogenetic analyses suggest that these genes were acquired independently of each other, even though they have become localized within the same genomic region. This hyperplastic region contains no detectable sequence features that might be mechanistically involved with the acquisition of host‐like genes, but does appear to be a site specifically associated with the acquisition process and may represent a novel facet of the evolution of marine cyanomyoviruses.
Transgenic chloroplasts are efficient sites for high‐yield production of the vaccinia virus envelope protein A27L in plant cells†
Authors: Rigano M. Manuela , Manna Carmela , Giulini Anna , Pedrazzini Emanuela , Capobianchi Maria , Castilletti Concetta , Di Caro Antonino , Ippolito Giuseppe , Beggio Paola , De Giuli Morghen Carlo , Monti Luigi , Vitale Alessandro , Cardi Teodoro 
Published: June 2009

SummaryOrthopoxviruses (OPVs) have recently received increasing attention because of their potential use in bioterrorism and the occurrence of zoonotic OPV outbreaks, highlighting the need for the development of safe and cost‐effective vaccines against smallpox and related viruses. In this respect, the production of subunit protein‐based vaccines in transgenic plants is an attractive approach. For this purpose, the A27L immunogenic protein of vaccinia virus was expressed in tobacco using stable transformation of the nuclear or plastid genome. The vaccinia virus protein was expressed in the stroma of transplastomic plants in soluble form and accumulated to about 18% of total soluble protein (equivalent to approximately 1.7 mg/g fresh weight). This level of A27L accumulation was 500‐fold higher than that in nuclear transformed plants, and did not decline during leaf development. Transplastomic plants showed a partial reduction in growth and were chlorotic, but reached maturity and set fertile seeds. Analysis by immunofluorescence microscopy indicated altered chlorophyll distribution. Chloroplast‐synthesized A27L formed oligomers, suggesting correct folding and quaternary structure, and was recognized by serum from a patient recently infected by a zoonotic OPV. Taken together, these results demonstrate that chloroplasts are an attractive production vehicle for the expression of OPV subunit vaccines.
Claiming evidence from non‐evidence: a reply to Morton and Harper
Authors: Bialystok Ellen 
Published: June 2009

Abstract
Morton and Harper (2007

) argue that research presented in support of a bilingual advantage in the development of executive control has been confounded with social class, the actual mechanism for group differences. As evidence, they report a study in which a small group of monolingual and bilingual 6‐ and 7‐year‐olds performed similarly on a Simon task. The present paper points to weaknesses in their experimental design, analysis, and logic that together undermine their criticism of the conclusion that bilingualism is responsible for the reported group differences.
Biological components of colour preference in infancy
Authors: Franklin Anna , Bevis Laura , Ling Yazhu , Hurlbert Anya 
Published: June 2009

AbstractAdult colour preference has been summarized quantitatively in terms of weights on the two fundamental neural processes that underlie early colour encoding: the S−(L+M) (‘blue–yellow’) and L−M (‘red–green’) cone‐opponent contrast channels (Ling, Hurlbert & Robinson, 2006; Hurlbert & Ling, 2007). Here, we investigate whether colour preference in 4–5‐month‐olds may be analysed in the same way. We recorded infants’ eye‐movements in response to pairwise presentations of eight colour stimuli varying only in hue. Infants looked longest at reddish and shortest at greenish hues. Analyses revealed that the L−M and S−(L+M) contrast between stimulus colour and background explained around half of the variation in infant preference across the hue spectrum. Unlike adult colour preference patterns, there was no evidence for sex differences in the weights on either of the cone‐opponent contrast components. The findings provide a quantitative model of infant colour preference that summarizes variation in infant preference across hues.
VIRTUE ETHICS AND THE SELECTION OF CHILDREN WITH IMPAIRMENTS: A REPLY TO ROSALIND MCDOUGALL
Authors: SAENZ CARLA 
Published: June 2009

ABSTRACTIn ‘Parental Virtues: A New Way of Thinking about the Morality of Reproductive Actions’ Rosalind McDougall proposes a virtue‐based framework to assess the morality of child selection. Applying the virtue‐based account to the selection of children with impairments does not lead, according to McDougall, to an unequivocal answer to the morality of selecting impaired children. In ‘Impairment, Flourishing, and the Moral Nature of Parenthood,’ she also applies the virtue‐based account to the discussion of child selection, and claims that couples with an impairment are morally justified in selecting a child with the same impairment. This claim, she maintains, reveals that the flourishing of a child should be understood as requiring environment‐specific characteristics. I argue that McDougall's argument begs the question. More importantly, it does not do justice to virtue ethics. I also question to what extent a virtue ethics framework can be successfully applied to discussions about the moral permissibility of reproductive actions.
Applying an activity system to online collaborative group work analysis
Authors: Choi Hyungshin , Kang Myunghee 
Published: June 2009

AbstractThis study determines whether an activity system provides a systematic framework to analyse collaborative group work. Using an activity system as a unit of analysis, the research examined learner behaviours, conflicting factors and facilitating factors while students engaged in collaborative work via asynchronous computer‐mediated communication. The online postings from the two highest and lowest performing groups of students during one semester were analysed, coded and reorganised. The coded postings of these four groups were then compared using an activity system to identify the difference in patterns of learner behaviours. The conflicting and facilitating factors that students encountered were identified as well. The findings provide implications for online collaborative learning environment design and mediating strategies. The study also addresses some of the challenges in using an activity system to analyse collaborative learning activities and provides suggestions for future research.
Codes of Good Governance
Authors: Aguilera Ruth V. , Cuervo‐Cazurra Alvaro 
Published: June 2009

ABSTRACTManuscript Type: ReviewResearch Question/Issue: We review the recent developments in the area of codes of good governance, a set of best practice recommendations regarding the behavior and structure of the board of directors.Research Findings/Results: Our review of the literature on codes of good governance highlights their rapid spread around the world and how academic research has lagged behind in analyzing this topic. Despite the criticism that the codes' voluntary nature limits their ability to improve governance practices, codes of good governance appear to have generally improved the governance of countries that have adopted them, although there is need for additional reforms.Theoretical Implications: Unfortunately, research on codes of good governance has developed in insolation with little cross‐fertilization across the different disciplines. We propose a multi‐level framework to discuss three main topics that have emerged within the codes literature: the motivations behind the diffusion of codes across countries and its implications for convergence of corporate governance practices; the content of the codes and their “comply or explain” dimension; and the relationship between code compliance and firm performance. We conclude by proposing four areas of future research.Practitical Implications: Code development, adoption, and compliance are directly related to issues surrounding the governance of the firm, and in particular to all the interactions that a director has inside and outside the firm. Codes are regulations that emerge from policy‐making negotiations between multiple stakeholders, such as the state (via the stock market regulators) and the investors.
Private Equity and Corporate Governance: Retrospect and Prospect
Authors: Wright Mike , Amess Kevin , Weir Charlie , Girma Sourafel 
Published: June 2009

ABSTRACTManuscript Type: ReviewResearch Question/Issue: We assess the corporate governance role and the impact of private equity.Research Findings/Results: Private equity firms are heterogeneous in their characteristics and activities. Nevertheless, a corporate governance structure with private equity involvement provides incentives to reduce agency and free cash flow problems. Additionally, private equity enhances the efficacy of the market for corporate control. Private equity investment is associated with performance gains, with such gains not simply being a result of transfers from other stakeholders. In the short term, the benefits appear clear to outgoing owners and to the new owners and management while in the longer term the benefits are less clear. While non‐financial stakeholders argue that other stakeholders suffer in the short and long term, the evidence to support this view is at best mixed.Theoretical Implications: By reviewing a comprehensive selection of theoretical and empirical papers published in refereed academic journals in finance, economics, entrepreneurship, and management as well as publicly available working papers and private equity industry studies, we develop a more complete understanding of private equity investment. Agency theory has shortcomings when applied to the broad sweep of private equity‐backed buyout types, as in some cases pre‐ownership change agency problems were likely low (e.g., family firms), in some cases the exploitation of growth opportunities owes more to the entrepreneurial behavior of managers than to improved incentives, and in some institutional contexts outside Anglo‐Saxon countries traditional agency issues are different and stakeholder interests are more important. There is a need for further theorizing on the heterogeneity of buyout and private equity types and the contexts in which they occur. Particularly useful perspectives seem to be entrepreneurial perspectives (e.g., entrepreneurial cognition, strategic entrepreneurship), stewardship theory, and institutional theory. Stakeholder governance theory (e.g., relating to employee ownership and participation) may also be useful for explaining wider distribution of gains.Practical Implications: Private equity investment is a positive feature of the corporate restructuring landscape. There is a need for managers and their advisors to be aware of the heterogeneity of the opportunities to create value and the expertise of different private equity firms. Policymakers designing mechanisms to regulate private equity need to be aware of the systematic evidence that shows a more positive impact of private equity than some have claimed, but also that there are heterogeneous effects relating to different types of buyouts and private equity firms that need to be taken into account.
Convergence of Corporate Governance: Critical Review and Future Directions
Authors: Yoshikawa Toru , Rasheed Abdul A. 
Published: June 2009

ABSTRACTManuscript Type:ReviewResearch Question/Issue:Convergence in corporate governance across countries has been a subject of interest and controversy in a variety of disciplines. We attempt to address a number of related research questions: (1) what constitutes convergence? (2) what are the drivers that propel corporations in different nations towards convergence? (3) what are the major impediments that stand in the way of convergence? (4) what empirical evidence do we have to suggest that we are moving towards or away from convergence? and (5) what would be some productive avenues for further research on this topic?Research Findings/Results:Despite the vigorous intellectual position of the proponents of convergence, there is only limited evidence to indicate that such convergence is actually occurring. Even when there is ostensible convergence, much of it is convergence in form rather than substance, and governance convergence is not a context‐free phenomenon.Theoretical Implications:Our review of the past literature suggests that increasing integration of product and capital markets is leading to changes in corporate governance around the world, but there is only limited evidence that such changes constitute convergence. Governance changes seem to be primarily attributable to the quest for greater efficiency in governance and enhanced legitimacy in capital markets. However, local forces such as institutional embeddedness and politics can hinder governance changes or create “hybrid” practices.Practical Implications:The ideal corporate governance may be institution‐ and firm‐specific and an imposition of new practices or standards may not lead to intended policy or performance outcomes.
Taking Stock of Corporate Governance Research While Looking to the Future
Authors: Filatotchev Igor , Boyd Brian K. 
Published: June 2009

ABSTRACTManuscript Type:EditorialResearch Question/Issue:This essay identifies some key issues for the analysis of corporate governance based on the articles within this special review issue coupled with our own perspectives. Our aim in this issue is to distil some research streams in the field and identify opportunities for future research.Research Findings/Results:We summarize the eight papers included in this special issue and briefly highlight their main contributions to the literature which collectively deal with the role and impact of corporate boards, codes of corporate governance, and the globalization of corporate governance systems. In addition to the new insights offered by these reviews, we attempt to offer our own ideas on where future research needs to be targeted.Theoretical Implications:We highlight a number of research themes where future governance research may prove fruitful. This includes taking a more holistic approach to corporate governance issues and developing an inter‐disciplinary perspective by building on agency theory while considering the rich new insights offered by complementary theories, such as behavioral theory, institutional theory and the resource‐based views of the firm. In particular, future corporate governance research needs to be conducted in multiple countries, particularly in emerging economies, if we want to move closer to the journal's aim of producing a global theory of corporate governance.Practical Implications:Our analysis suggests that analytic and regulatory approaches to corporate governance issues should move from a “one‐size‐fits‐all” template to taking into account organizational, institutional and national contexts.
Realtime Sequential Inference of Static Parameters with Expensive Likelihood Calculations
Authors: Robins P. , Rapley V. E. , Green N. 
Published: June 2009

SummaryA methodology is developed for making inference about parameters of a possible covert chemical or biological atmospheric release from sensor readings. The key difficulty in performing this inference is that the results must be obtained in a very short timescale (5 min) to make use of the inference for protection. The methodology that is developed uses some of the components in a sequential Monte Carlo algorithm. However, this inference problem is different from many other sequential Monte Carlo problems, in that there are no state evolution equations, the forward model is highly non-linear and the likelihoods are non-Gaussian. The algorithm that is developed can use stored output from complex physics models for more rapid update of the posterior from new data without having to rerun the models. The use of differential evolution Markov chain sampling allows new samples to diverge rapidly from degenerate sample sets. Results for inferences made of atmospheric releases (both real and simulated) of material are presented, demonstrating that the sampling scheme performs adequately despite constraints of a short time span for calculations.
Spatiotemporal Smoothing and Sulphur Dioxide Trends Over Europe
Authors: Bowman Adrian W. , Giannitrapani Marco , Marian Scott E. 
Published: June 2009

SummarySpatiotemporal models for sulphur dioxide pollution over Europe are considered within an additive model framework. A suitable description of the spatiotemporal correlation structure of the data is constructed and incorporated in the analysis of the additive model, to ensure that standard errors and other forms of analysis reflect the form of variation that is exhibited by the data. To deal with the large sample size, an updating formula based on binning is derived to provide a computationally manageable implementation of the back-fitting algorithm. Interaction terms involving space, time and seasonal effects are also considered. This requires three-dimensional smoothing which is implemented by repeated application of lower dimensional marginal smoothing operations. The properties of this form of smoothing are examined and the estimators are shown to have first-order behaviour, inherited from the marginal operations, which is equivalent to the full multivariate versions. These models and methods are applied to the sulphur dioxide data, allowing detailed and informative descriptions of the spatiotemporal patterns to be created.