887 resultados para Multisensory integration
Resumo:
Knowledge of the spatial distribution of hydraulic conductivity (K) within an aquifer is critical for reliable predictions of solute transport and the development of effective groundwater management and/or remediation strategies. While core analyses and hydraulic logging can provide highly detailed information, such information is inherently localized around boreholes that tend to be sparsely distributed throughout the aquifer volume. Conversely, larger-scale hydraulic experiments like pumping and tracer tests provide relatively low-resolution estimates of K in the investigated subsurface region. As a result, traditional hydrogeological measurement techniques contain a gap in terms of spatial resolution and coverage, and they are often alone inadequate for characterizing heterogeneous aquifers. Geophysical methods have the potential to bridge this gap. The recent increased interest in the application of geophysical methods to hydrogeological problems is clearly evidenced by the formation and rapid growth of the domain of hydrogeophysics over the past decade (e.g., Rubin and Hubbard, 2005).
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The need for better gene transfer systems towards improved risk=benefit balance for patients remains a major challenge in the clinical translation of gene therapy (GT). We have investigated the improvement of integrating vectors safety in combining (i) new short synthetic genetic insulator elements (GIE) and (ii) directing genetic integration to heterochromatin. We have designed SIN-insulated retrovectors with two candidate GIEs and could identify a specific combination of insulator 2 repeats which translates into best functional activity, high titers and boundary effect in both gammaretro (p20) and lentivectors (DCaro4) (see Duros et al, abstract ibid). Since GIEs are believed to shield the transgenic cassette from inhibitory effects and silencing, DCaro4 has been further tested with chimeric HIV-1 derived integrases which comprise C-ter chromodomains targeting heterochromatin through either histone H3 (ML6chimera) or methylatedCpGislands (ML10). With DCaro4 only and both chimeras, a homogeneous expression is evidenced in over 20% of the cells which is sustained over time. With control lentivectors, less than 2% of cells express GFP as compared to background using a control double-mutant in both catalytic and ledgf binding-sites; in addition, a two-times increase of expression can be induced with histone deacetylase inhibitors. Our approach could significantly reduce integration into open chromatin sensitive sites in stem cells at the time of transduction, a feature which might significantly decrease subsequent genotoxicity, according to X-SCIDs patients data.Work performed with the support of EC-DG research within the FP6-Network of Excellence, CLINIGENE: LSHB-CT-2006-018933
Resumo:
The aim of the present study was to determine whether and how rats can use local olfactory cues for spatial orientation. Rats were trained in an eight-arm radial maze under different conditions as defined by the presence or absence of supplementary olfactory cues marking each arm, the availability of distant visuospatial information, and the illumination of the maze (light or darkness). The different visual conditions were designed to dissociate among the effects of light per se and those of visuospatial cues, on the use of olfactory cues for accurate arm choice. Different procedures with modifications of the arrangement of olfactory cues were used to determine if rats formed a representation of the spatial configuration of the olfactory cues and if they could rely on such a representation for accurate arm choice in the radial maze. The present study demonstrated that the use of olfactory cues to direct arm choice in the radial arm maze was critically dependent on the illumination conditions and implied two different modes of processing of olfactory information according to the presence or the absence of light. Olfactory cues were used in an explicit manner and enabled accurate arm choice only in the absence of light. Rats, however, had an implicit memory of the location of the olfactory cues and formed a representation of the spatial position of these cues, whatever the lighting conditions. They did not memorize the spatial configuration of the olfactory cues per se but needed these cues to be linked to the external spatial frame of reference.
Resumo:
Multisensory stimuli can improve performance, facilitating RTs on sensorimotor tasks. This benefit is referred to as the redundant signals effect (RSE) and can exceed predictions on the basis of probability summation, indicative of integrative processes. Although an RSE exceeding probability summation has been repeatedly observed in humans and nonprimate animals, there are scant and inconsistent data from nonhuman primates performing similar protocols. Rather, existing paradigms have instead focused on saccadic eye movements. Moreover, the extant results in monkeys leave unresolved how stimulus synchronicity and intensity impact performance. Two trained monkeys performed a simple detection task involving arm movements to auditory, visual, or synchronous auditory-visual multisensory pairs. RSEs in excess of predictions on the basis of probability summation were observed and thus forcibly follow from neural response interactions. Parametric variation of auditory stimulus intensity revealed that in both animals, RT facilitation was limited to situations where the auditory stimulus intensity was below or up to 20 dB above perceptual threshold, despite the visual stimulus always being suprathreshold. No RT facilitation or even behavioral costs were obtained with auditory intensities 30-40 dB above threshold. The present study demonstrates the feasibility and the suitability of behaving monkeys for investigating links between psychophysical and neurophysiologic instantiations of multisensory interactions.
Resumo:
The question of where retroviral DNA becomes integrated in chromosomes is important for understanding (i) the mechanisms of viral growth, (ii) devising new anti-retroviral therapy, (iii) understanding how genomes evolve, and (iv) developing safer methods for gene therapy. With the completion of genome sequences for many organisms, it has become possible to study integration targeting by cloning and sequencing large numbers of host-virus DNA junctions, then mapping the host DNA segments back onto the genomic sequence. This allows statistical analysis of the distribution of integration sites relative to the myriad types of genomic features that are also being mapped onto the sequence scaffold. Here we present methods for recovering and analyzing integration site sequences.
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Metabolic homeostasis is achieved by complex molecular and cellular networks that differ significantly among individuals and are difficult to model with genetically engineered lines of mice optimized to study single gene function. Here, we systematically acquired metabolic phenotypes by using the EUMODIC EMPReSS protocols across a large panel of isogenic but diverse strains of mice (BXD type) to study the genetic control of metabolism. We generated and analyzed 140 classical phenotypes and deposited these in an open-access web service for systems genetics (www.genenetwork.org). Heritability, influence of sex, and genetic modifiers of traits were examined singly and jointly by using quantitative-trait locus (QTL) and expression QTL-mapping methods. Traits and networks were linked to loci encompassing both known variants and novel candidate genes, including alkaline phosphatase (ALPL), here linked to hypophosphatasia. The assembled and curated phenotypes provide key resources and exemplars that can be used to dissect complex metabolic traits and disorders.
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Tämän tutkielman tavoitteena on perehtyä globaalin yrityksen laskentatoimen tietojärjestelmien yhtenäistämiseen ja käyttöönottoon esimerkkinä UPM-Kymmene konsernin projekti. Tutkielmassa sovelletaan hermeneuttista tutkimusotetta. Teoreettisesti aihetta tarkastellaan globalisoitumisen ja laskentatoimen tietojärjestelmille asetettavien vaatimusten pohjalta, sekä järjestelmän muutosprosessin eri vaiheissa huomioon otettavien muuttujien perusteella. Yhtenäisen laskentatoimen tietojärjestelmän tuomat edut globaalille yritykselle ovat ilmeisiä. Ennen yhtenäisen projektin kehittelyä on olennaista tutkia lähtökohdat projektin onnistumiselle ja suunnitella projektin eri vaiheet huolella. Tutkielmassa havaitaan myös, että globaalissa yrityksessä tulee huomioida eri yrityskulttuurit sekä tulosyksiköiden erilaiset toimintatavat. Johtopäätöksenä todetaan, että sekä yritysjohdon että tulosyksiköiden sitoutuneisuus projektiin ja yhtenäiset tavoitteet ovat oleellisia projektin onnistumisen kannalta.
Resumo:
Adult neurogenesis is regulated by the neurogenic niche, through mechanisms that remain poorly defined. Here, we investigated whether niche-constituting astrocytes influence the maturation of adult-born hippocampal neurons using two independent transgenic approaches to block vesicular release from astrocytes. In these models, adult-born neurons but not mature neurons showed reduced glutamatergic synaptic input and dendritic spine density that was accompanied with lower functional integration and cell survival. By taking advantage of the mosaic expression of transgenes in astrocytes, we found that spine density was reduced exclusively in segments intersecting blocked astrocytes, revealing an extrinsic, local control of spine formation. Defects in NMDA receptor (NMDAR)-mediated synaptic transmission and dendrite maturation were partially restored by exogenous D-serine, whose extracellular level was decreased in transgenic models. Together, these results reveal a critical role for adult astrocytes in local dendritic spine maturation, which is necessary for the NMDAR-dependent functional integration of newborn neurons.
Resumo:
This study analyzed high-density event-related potentials (ERPs) within an electrical neuroimaging framework to provide insights regarding the interaction between multisensory processes and stimulus probabilities. Specifically, we identified the spatiotemporal brain mechanisms by which the proportion of temporally congruent and task-irrelevant auditory information influences stimulus processing during a visual duration discrimination task. The spatial position (top/bottom) of the visual stimulus was indicative of how frequently the visual and auditory stimuli would be congruent in their duration (i.e., context of congruence). Stronger influences of irrelevant sound were observed when contexts associated with a high proportion of auditory-visual congruence repeated and also when contexts associated with a low proportion of congruence switched. Context of congruence and context transition resulted in weaker brain responses at 228 to 257 ms poststimulus to conditions giving rise to larger behavioral cross-modal interactions. Importantly, a control oddball task revealed that both congruent and incongruent audiovisual stimuli triggered equivalent non-linear multisensory interactions when congruence was not a relevant dimension. Collectively, these results are well explained by statistical learning, which links a particular context (here: a spatial location) with a certain level of top-down attentional control that further modulates cross-modal interactions based on whether a particular context repeated or changed. The current findings shed new light on the importance of context-based control over multisensory processing, whose influences multiplex across finer and broader time scales.
Resumo:
The adult hippocampus generates functional dentate granule cells (GCs) that release glutamate onto target cells in the hilus and cornus ammonis (CA)3 region, and receive glutamatergic and γ-aminobutyric acid (GABA)ergic inputs that tightly control their spiking activity. The slow and sequential development of their excitatory and inhibitory inputs makes them particularly relevant for information processing. Although they are still immature, new neurons are recruited by afferent activity and display increased excitability, enhanced activity-dependent plasticity of their input and output connections, and a high rate of synaptogenesis. Once fully mature, new GCs show all the hallmarks of neurons generated during development. In this review, we focus on how developing neurons remodel the adult dentate gyrus and discuss key aspects that illustrate the potential of neurogenesis as a mechanism for circuit plasticity and function.
Resumo:
Internationally, policies for attracting highly-skilled migrants have become the guidelines mainly used by the Organisation for Economic Co-operation and Development (OECD) countries. Governments are implementing specific procedures to capture and facilitate their mobility. However, all professions are not equal when it comes to welcoming highly-skilled migrants. The medical profession, as a protective market, is one of these. Taking the case of non-EU/EEA doctors in France, this paper shows that the medical profession defined as the closed labour market, remains the most controversial in terms of professional integration of migrants, protectionist barriers to migrant competition and challenge of medical shortage. Based on the path-dependency approach, this paper argues that non-EU/EEA doctors' issues in France derive from a complex historical process of interaction between standards settled in the past, particularly the historical power of medical corporatism, the unexpected long-term effects of French hospital reforms of 1958, and budgetary pressures. Theoretically, this paper shows two significant findings. Firstly, the French medical system has undergone a series of transformations unthinkable in the strict sense of a path-dependence approach: an opening of the medical profession to foreign physicians in the context of the Europeanisation of public policy, acceptance of non-EU/EEA doctors in a context of medical shortage and budgetary pressures. Secondly, there is no change of the overall paradigm: significantly, the recruitment policies of non-EU/EEA doctors continue to highlight the imprint of the past and reveal a significant persistence of prejudices. Non-EU/EEA doctors are not considered legitimate doctors even if they have the qualifications of physicians which are legitimate in their country and which can be recognised in other receiving countries.
Resumo:
Discussions concerning the challenges of combining work and family are certainly not new, and still actively continue. There is, however, a silence in the related literature regarding a comprehensive description of integrating specifically university academic ~. work and family responsibilities. This silence is especially evident for men who are parents as well as academics. With the participation of 4 key informants, this qualitative research study gave voice to men and women who participate in the academic labour of a Canadian university as professors, and as graduate students, along with the parenting labour of at least 1 child under the age of7. Methodology was developed to reveal in-depth perspectives regarding the work practices employed by 4 key informants as they combined intellectual and child-care responsibilities. Multiple data collection methods included journal reflections, day time observation sessions, a focus group, and a final evaluation questionnaire. Using research findings, together with information extrapolated from Three Models of the Family (Eichler, 1997), this study also took steps toward developing a Proposed "Three Models of the University," to offer explanation for the work practices of the key informants as academics/parents, and also for future consideration in university policy formation.
Resumo:
This research acknowledges the difficulties experienced by teachers presenting integrated arts curricula. Instructional support is offered by arts organizations that provide arts partnerships with local schools boards. The study focuses on the experiences of 8 teachers from a Catholic school board in southern Ontario who participated in integrated arts programs offered by The Royal Conservatory of Music's Learning Through the Arts™ (LTTATM) program and a local art gallery's Art Based Integrated Learning (ABIL) program and examines their responses to the programs and their perception of personal and professional development through this association. Additionally, questions were posed to the . "aftisfs"from-tneSe]Jfograrrrs;-and"they liiscus·sed·how"participating in-collaboration with teachers in the development of in-school programs enabled them to experience personal and professional development as well. Seven themes emerged from the data. These themes included: teachers' feelings of a lack of preparedness to teach the arts; the value of the arts and arts partnerships in schools; the role of the artists in the education of teachers; professional development for both teachers and artists; the development of collegiality; perceptions of student engagement; and the benefits and obstacles of integrating the arts into the curriculum. This document highlights the benefits to both teachers and artists of arts partnerships between schools and outside arts organizations.
Resumo:
Adenoviral vectors are currently the most widely used gene therapeutic vectors, but their inability to integrate into host chromosomal DNA shortened their transgene expression and limited their use in clinical trials. In this project, we initially planned to develop a technique to test the effect of the early region 1 (E1) on adenovirus integration by comparing the integration efficiencies between an E1-deleted adenoviral vector (SubE1) and an Elcontaining vector (SubE3). However, we did not harvest any SubE3 virus, even if we repeated the transfection and successfully rescued the SubE1 virus (2/4 transfections generated viruses) and positive control virus (6/6). The failure of rescuing SubE3 could be caused by the instability of the genomic plasmid pFG173, as it had frequent intemal deletions when we were purifying It. Therefore, we developed techniques to test the effect of E1 on homologous recombination (HR) since literature suggested that adenovirus integration is initiated by HR. We attempted to silence the E1 in 293 cells by transfecting E1A/B-specific small interfering RNA (siRNA). However, no silenced phenotype was observed, even if we varied the concentrations of E1A/B siRNA (from 30 nM to 270 nM) and checked the silencing effects at different time points (48, 72, 96 h). One possible explanation would be that the E1A/B siRNA sequences are not potent enough to Induce the silenced phenotype. For evaluating HR efficiencies, an HR assay system based on bacterial transfonmatJon was designed. We constmcted two plasmids ( designated as pUC19-dl1 and pUC19-dl2) containing different defective lacZa cassettes (forming white colonies after transformation) that can generate a functional lacZa cassette (forming blue colonies) through HR after transfecting into 293 cells. The HR efficiencies would be expressed as the percentages of the blue colonies among all the colonies. Unfortunately, after transfonnation of plasmid isolated from 293 cells, no colony was found, even at a transformation efficiency of 1.8x10^ colonies/pg pUC19, suggesting the sensitivity of this system was low. To enhance the sensitivity, PCR was used. We designed a set of primers that can only amplify the recombinant plasmid fomied through HR. Therefore, the HR efficiencies among different treatments can be evaluated by the amplification results, and this system could be used to test the effect of E1 region on adenovirus integration. In addition, to our knowledge there was no previous studies using PCR/ Realtime PCR to evaluate HR efficiency, so this system also provides a PCR-based method to carry out the HR assays.
Resumo:
This study \Alas initiated in response to the Junior Division Review (1985) publ ished by the Ministry of Education for the Province of Ontario. Curriculum integration is an element used within the educational paradigm designed by the Ontario Ministry of Education. It is a term frequent1y verbal ized b>' educators in this province, but because of 1 imi ted resource support regarding this methodology, it was open to broad interpretation resulting in an extreme v ar i at i on i nit simp 1 eme n tat i on • I n de ed, the Min i s try intimated that it was not occurring to any significant degree across the province. The objective of this thes is was· to define integration in the junior classroom and de-:.ign a meas.ur·ement in-:.tr-ument which would in turn high 1 i gh t indicators of curriculum integration. The :.tudy made a prel iminary, field-based survey of educa tiona 1 professionals in order to generate a relevant description of integrated curr-iculum programm i ng as def i ned in the j un i or classroom. The description was a compilation of views expressed by a random selection of teachers, consultants, supervisory officers and principals. The survey revea 1 ed a much more comprehens i ve vi et·<,l of the attributes of integrated programming than tradition would dictate and resulted in a functional definition tha t was broader than past prac t ices. Based on the information generated by this survey, an instrument ou t 1 in i ng program cr iter i a of was devised. an integrated junior cla~·sroom Th i s measuremen t i nstrumen t , designed for all levels of educators, was named uThe Han~.son I nstrumen t for the Measuremen t of Program Integrat ion in the Jun i or Cl assroom". It refl ected five categories intrinsic to the me thodol ogy of integration: Teacher Behaviour, Student Behaviour, Classroom Layout, Cl as~·r oom Environment and Progr amm i ng. Each category and the items therein were successfully tested in val idi ty and rel iabi 1 i ty checKs. Interestingly, the individual class was found to be the major variable programming in in the measuremen t the j un i or d i vis i on • of The integrated instrument demonstrated potential not onl)' a~· an initial measure of the degree of integrated curriculum, but as a guide to strategies to implement such a methodology.