Looming signals reveal synergistic principles of multisensory integration.

Multisensory interactions are a fundamental feature of brain organization. Principles governing multisensory processing have been established by varying stimulus location, timing and efficacy independently. Determining whether and how such principles operate when stimuli vary dynamically in their perceived distance (as when looming/receding) provides an assay for synergy among the above principles and also means for linking multisensory interactions between rudimentary stimuli with higher-order signals used for communication and motor planning. Human participants indicated movement of looming or receding versus static stimuli that were visual, auditory, or multisensory combinations while 160-channel EEG was recorded. Multivariate EEG analyses and distributed source estimations were performed. Nonlinear interactions between looming signals were observed at early poststimulus latencies (∼75 ms) in analyses of voltage waveforms, global field power, and source estimations. These looming-specific interactions positively correlated with reaction time facilitation, providing direct links between neural and performance metrics of multisensory integration. Statistical analyses of source estimations identified looming-specific interactions within the right claustrum/insula extending inferiorly into the amygdala and also within the bilateral cuneus extending into the inferior and lateral occipital cortices. Multisensory effects common to all conditions, regardless of perceived distance and congruity, followed (∼115 ms) and manifested as faster transition between temporally stable brain networks (vs summed responses to unisensory conditions). We demonstrate the early-latency, synergistic interplay between existing principles of multisensory interactions. Such findings change the manner in which to model multisensory interactions at neural and behavioral/perceptual levels. We also provide neurophysiologic backing for the notion that looming signals receive preferential treatment during perception.

Enterprise Architecture Principles in Research and Practice: Insights from an Exploratory Analysis

Even though architecture principles were first discussed in the 1990s, they are still perceived as an underexplored topic in enterprise architecture management research. By now, there is an increasing consensus about EA principles' nature, as well as guidelines for their formulation. However, the extant literature remains vague about what can be considered suitable EA design and evolution guidance principles. In addition, empirical insights regarding their role and usefulness in practice are still lacking. Accordingly, this research seeks to address three questions: (1) What are suitable principles to guide EA design and evolution? (2) What usage do EA principles have for practitioners? (3) Which propositions can be derived regarding EA principles' role and application? Opting for exploratory research, we apply a research process covering critical analysis of current publications as well as capturing experts' perceptions. Our research ontologically distinguishes between principles from nonprinciples, proposes a validated set of meta-principles, and clarifies principles' application, role, and usefulness in practice. The explored insights can be used as guidelines in defining suitable principles and turning them into an effective bridge between strategy and design and a guide in design decisions.

Principes d'evaluation et de prise en charge des patients agés polymorbides: guide a l'intention des cliniciens [Principles for the assessment and management of polymorbid elderly patients: a guide for clinicians].

Providing care to multimorbid older patients is complex, not only because of the coexistence of multiple chronic conditions, but also because of their frequent intrication with psychological and social problems. This article describes a guide for clinicians to assess and manage multimorbid older patients. This guide was adapted from the work of a group of expert US geriatricians. It proposes seven steps: identification of the main problem; identification of patients' preferences; setting of goals of care; estimation of life expectancy; identification of relevant evidence in the literature; revision of the plan of care; and discussion of the options with the patient. The use of this guide is illustrated by a clinical case.

Enterprise Architecture Management Design: Towards Understanding Organizational Contingencies, Design Principles and Effectiveness

Despite the increasing popularity of enterprise architecture management (EAM) in practice, many EAM initiatives either do not fully meet the expected targets or fail. Several frameworks have been suggested as guidelines to EA implementation, but companies seldom follow prescriptive frameworks. Instead, they follow very diverse implementation approaches that depend on their organizational contingencies and the way of adopting and evolving EAM over time. This research strives for a broader understanding of EAM by exploring context-dependent EAM adoption approaches as well as identifying the main EA principles that affect EA effectiveness. Based on two studies, this dissertation aims to address two main questions: (1) EAM design: Which approaches do companies follow when adopting EAM? (2) EA principles and their impact: What impact does EA principles have on EA effectiveness/quality? By utilizing both qualitative and quantitative research methods, this research contributes to exploring different EAM designs in different organizational contingencies as well as using EA principles as an effective means to achieve principle-based EAM design. My research can help companies identify a suitable EAM design that fits their organizational settings and shape their EA through a set of principles.

MR connectomics: Principles and challenges.

MR connectomics is an emerging framework in neuro-science that combines diffusion MRI and whole brain tractography methodologies with the analytical tools of network science. In the present work we review the current methods enabling structural connectivity mapping with MRI and show how such data can be used to infer new information of both brain structure and function. We also list the technical challenges that should be addressed in the future to achieve high-resolution maps of structural connectivity. From the resulting tremendous amount of data that is going to be accumulated soon, we discuss what new challenges must be tackled in terms of methods for advanced network analysis and visualization, as well data organization and distribution. This new framework is well suited to investigate key questions on brain complexity and we try to foresee what fields will most benefit from these approaches.

Suivi thérapeutique des médicaments (I). Les principes [Principles of therapeutic drug monitoring]

Requesting a blood level measurement of a drug is part of the global approach known as "Therapeutic Drug Monitoring". Diverse situations require this monitoring approach, such as inadequate response to treatment or organ failure. Every drug however does not possess all the characteristics for a TDM program. The therapeutic range of a TDM drug has indeed to be narrow and its interindividual pharmacokinetic variability to be wide. As the development of new drugs is currently slowing down, the precise management of existing treatments certainly deserves progress, but needs however to be applied rationally, starting from a valid indication to blood sampling, and ending with a sound dosage adaptation decision.

Essays on the principles and adoption of entreprise-wide architecture

Enterprise-wide architecture has become a necessity for organizations to (re)align information technology (IT) to changing business requirements. Since a city planning metaphor inspired enterprise-wide architecture, this dissertation's research axes can be outlined by similarities between cities and enterprises. Both are characterized as dynamic super-systems that need to address the evolving interest of various architecture stakeholders. Further, both should simultaneously adhere to a set of principles to guide the evolution of architecture towards the expected benefits. The extant literature on enterprise-wide architecture not only disregards architecture adoption's complexities but also remains vague about how principles guide architecture evolution. To bridge this gap, this dissertation contains three interrelated research streams examining the principles and adoption of enterprise-wide architecture. The first research stream investigates organizational intricacies inherent in architecture adoption. It characterizes architecture adoption as an ongoing organizational adaptation process. By analyzing organizational response behaviors in this adaptation process, it also identifies four archetypes that represent very diverse architecture approaches. The second research stream ontologically clarifies the nature of architecture principles along with outlining new avenues for theoretical contributions. This research stream also provides an empirically validated set of principles and proposes a research model illustrating how principles can be applied to generate expected architecture benefits. The third research stream examines architecture adoption in multinational corporations (MNCs). MNCs are Specified by unique organizational characteristics that constantly strive for balancing global integration and local responsiveness. This research stream characterizes MNCs' architecture adoption as a continuous endeavor. This endeavor tries to constantly synchron ize architecture with stakeholders' beliefs about how to balance global integration and local responsiveness. To conclude, this dissertation provides a thorough explanation of a long-term journey in Which organizations learn over time to adopt an effective architecture approach. It also clarifies the role of principles to purposefully guide the aforementioned learning process. - L'Architecture d'Entreprise (AE) est devenue une nécessité pour permettre aux organisations de (ré)aligner les technologies de l'information (TI) avec les changements en termes de besoins métiers. En se basant sur la métaphore de la planification urbaine dont l'AE s'est inspirée, cette dissertation peut être présentée comme une comparaison entre les villes et les entreprises; les deux sont des super-systèmes dynamiques ayant besoin de répondre aux intérêts d'acteurs divers et variés en constants évolution. De plus, les deux devraient souscrire simultanément à un ensemble de principes afin de faire converger l'évolution de l'architecture vers les bénéfices attendus. La littérature sur l'AE, non seulement ne prend pas en considération les complexités de l'adoption d'architecture, mais aussi reste vague sur la manière dont les principes guident l'évolution de l'architecture. Pour pallier ce manque, cette dissertation est composée de trois volets de recherche étroitement liés examinant les principes et l'adoption de l'AE. Le premier volet examine la complexité organisationnelle inhérente à l'adoption de l'architecture. Il caractérise l'adoption de l'architecture en tant que processus d'adaptation continu. En analysant le comportement organisationnel en réponse à ce processus d'adaptation, ce volet distingue quatre archétypes représentant la diversité des approches de l'architecture. Le deuxième volet de recherche clarifie de manière ontologique la nature des principes d'architecture et envisage les contributions théoriques futures possibles. Cet axe de recherche fournit aussi un ensemble de principes, validés de manière empirique, et propose un modèle de recherche illustrant la manière dont ces principes peuvent être appliqués afin de générer les bénéfices attendus de l'architecture. Le troisième volet examine l'adoption de l'architecture dans les entreprises multinationales. Ces dernières possèdent des caractéristiques organisationnelles uniques et sont constamment à la recherche d'un équilibre entre une intégration globale et une flexibilité locale tout en prenant en compte les convictions des divers acteurs sur la manière d'atteindre cet équilibre. Pour conclure, cette dissertation fournit une explication sur le long voyage au cours duquel les entreprises apprennent à adopter une approche d'architecture efficace. Elle clarifie aussi le rôle des principes dans l'accompagnement de ce processus d'apprentissage.

Organizing principles across the senses

ABSTRACT This thesis is composed of two main parts. The first addressed the question of whether the auditory and somatosensory systems, like their visual counterpart, comprise parallel functional pathways for processing identity and spatial attributes (so-called `what' and `where' pathways, respectively). The second part examined the independence of control processes mediating task switching across 'what' and `where' pathways in the auditory and visual modalities. Concerning the first part, electrical neuroimaging of event-related potentials identified the spatio-temporal mechanisms subserving auditory (see Appendix, Study n°1) and vibrotactile (see Appendix, Study n°2) processing during two types of blocks of trials. `What' blocks varied stimuli in their frequency independently of their location.. `Where' blocks varied the same stimuli in their location independently of their frequency. Concerning the second part (see Appendix, Study n°3), a psychophysical task-switching paradigm was used to investigate the hypothesis that the efficacy of control processes depends on the extent of overlap between the neural circuitry mediating the different tasks at hand, such that more effective task preparation (and by extension smaller switch costs) is achieved when the anatomical/functional overlap of this circuitry is small. Performance costs associated with switching tasks and/or switching sensory modalities were measured. Tasks required the analysis of either the identity or spatial location of environmental objects (`what' and `where' tasks, respectively) that were presented either visually or acoustically on any given trial. Pretrial cues informed participants of the upcoming task, but not of the sensory modality. - In the audio-visual domain, the results showed that switch costs between tasks were significantly smaller when the sensory modality of the task switched versus when it repeated. In addition, switch costs between the senses were correlated only when the sensory modality of the task repeated across trials and not when it switched. The collective evidence not only supports the independence of control processes mediating task switching and modality switching, but also the hypothesis that switch costs reflect competitive interterence between neural circuits that in turn can be diminished when these neural circuits are distinct. - In the auditory and somatosensory domains, the findings show that a segregation of location vs. recognition information is observed across sensory systems and that these happen around 100ms for both sensory modalities. - Also, our results show that functionally specialized pathways for audition and somatosensation involve largely overlapping brain regions, i.e. posterior superior and middle temporal cortices and inferior parietal areas. Both these properties (synchrony of differential processing and overlapping brain regions) probably optimize the relationships across sensory modalities. - Therefore, these results may be indicative of a computationally advantageous organization for processing spatial anal identity information.

Guidelines for imaging retinoblastoma: imaging principles and MRI standardization.

Retinoblastoma is the most common intraocular tumor in children. The diagnosis is usually established by the ophthalmologist on the basis of fundoscopy and US. Together with US, high-resolution MRI has emerged as an important imaging modality for pretreatment assessment, i.e. for diagnostic confirmation, detection of local tumor extent, detection of associated developmental malformation of the brain and detection of associated intracranial primitive neuroectodermal tumor (trilateral retinoblastoma). Minimum requirements for pretreatment diagnostic evaluation of retinoblastoma or mimicking lesions are presented, based on consensus among members of the European Retinoblastoma Imaging Collaboration (ERIC). The most appropriate techniques for imaging in a child with leukocoria are reviewed. CT is no longer recommended. Implementation of a standardized MRI protocol for retinoblastoma in clinical practice may benefit children worldwide, especially those with hereditary retinoblastoma, since a decreased use of CT reduces the exposure to ionizing radiation.

Chirurgie bariatrique en 2013: principes, avantages et inconvénients des interventions a disposition [Bariatric surgery in 2013: principles, advantages and disadvantages of the available procedures].

For severe obesity (BMI > 35 kg/m2), bariatric surgery is not only the best, but often the only means of obtaining sufficient and durable weight loss. This article aims to review the available bariatric procedures. Gastric bypass remains the reference when it comes to the risk/benefit ratio. Gastric banding is declining rapidly due to the high prevalence of long-term complications. Primary malabsorptive procedures remain largely unpopular because of their potential nutritional complications. Sleeve gastrectomy, although it is not reversible as it includes a significant gastric resection, increases currently in popularity because of its apparent simplicity and the fact that early results regarding weight loss mimic those obtained with gastric bypass.