898 resultados para primate reconciliation
Resumo:
This thesis describes a series of experimental investigations into the functional organisation of human visual cortex using neuromagnetometry.This technique combines good spatial and temporal resolution enabling identification of the location and temporal response characteristics of cortical neurones within alert humans. To activate different neuronal populations and cortical areas a range of stimuli were used, the parameters of which were selected to match the known physiological properties of primate cortical neurones. In one series of experiments the evoked magnetic response was recorded to isoluminant red/green gratings. Co-registration of signal and magnetic resonance image data indicated a contribution to the response from visual areas V1, V2 and V4. To investigate the spatio-temporal characteristics of neurones within area V1 the evoked response was recorded for a range of stimulus spatial and temporal frequencies. The response to isoluminant red/green gratings was dominated by a major component which was found to have bandpass spatial frequency tuning with a peak at 1-2 cycles/degree, falling to the level of the noise at 6-8 cycles/degree. The temporal frequency tuning characteristics of the response showed bimodal sensitivity with peaks at 0-1Hz and 4Hz. In a further series of experiments the luminance evoked response was recorded to red/black, yellow/black and achromatic gratings and in all cases was found to be more complex than the isoluminant chromatic response, comprising up to three distinct components. The major response peak showed bandpass spatial frequency tuning characteristics, peaking at 6-8 cycles/degree, falling to the level of the noise at 12-16 cycles/degree. The results provide evidence to suggest that within area V1 the same neuronal population encodes both chromatic and luminance information and has spatial frequency tuning properties consistent with single-opponent cells. Furthermore, the results indicate that cells within area V1 encode chromatic motion information over a wide range of temporal frequencies with temporal response characteristics suggestive of the existence of a sub-population of cells sensitive to high temporal frequencies.
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Preface. The evolution of cognitive neuroscience has been spurred by the development of increasingly sophisticated investigative techniques to study human cognition. In Methods in Mind, experts examine the wide variety of tools available to cognitive neuroscientists, paying particular attention to the ways in which different methods can be integrated to strengthen empirical findings and how innovative uses for established techniques can be developed. The book will be a uniquely valuable resource for the researcher seeking to expand his or her repertoire of investigative techniques. Each chapter explores a different approach. These include transcranial magnetic stimulation, cognitive neuropsychiatry, lesion studies in nonhuman primates, computational modeling, psychophysiology, single neurons and primate behavior, grid computing, eye movements, fMRI, electroencephalography, imaging genetics, magnetoencephalography, neuropharmacology, and neuroendocrinology. As mandated, authors focus on convergence and innovation in their fields; chapters highlight such cross-method innovations as the use of the fMRI signal to constrain magnetoencephalography, the use of electroencephalography (EEG) to guide rapid transcranial magnetic stimulation at a specific frequency, and the successful integration of neuroimaging and genetic analysis. Computational approaches depend on increased computing power, and one chapter describes the use of distributed or grid computing to analyze massive datasets in cyberspace. Each chapter author is a leading authority in the technique discussed.
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Magnetoencephalography (MEG) can be used to reconstruct neuronal activity with high spatial and temporal resolution. However, this reconstruction problem is ill-posed, and requires the use of prior constraints in order to produce a unique solution. At present there are a multitude of inversion algorithms, each employing different assumptions, but one major problem when comparing the accuracy of these different approaches is that often the true underlying electrical state of the brain is unknown. In this study, we explore one paradigm, retinotopic mapping in the primary visual cortex (V1), for which the ground truth is known to a reasonable degree of accuracy, enabling the comparison of MEG source reconstructions with the true electrical state of the brain. Specifically, we attempted to localize, using a beanforming method, the induced responses in the visual cortex generated by a high contrast, retinotopically varying stimulus. Although well described in primate studies, it has been an open question whether the induced gamma power in humans due to high contrast gratings derives from V1 rather than the prestriate cortex (V2). We show that the beanformer source estimate in the gamma and theta bands does vary in a manner consistent with the known retinotopy of V1. However, these peak locations, although retinotopically organized, did not accurately localize to the cortical surface. We considered possible causes for this discrepancy and suggest that improved MEG/magnetic resonance imaging co-registration and the use of more accurate source models that take into account the spatial extent and shape of the active cortex may, in future, improve the accuracy of the source reconstructions.
Resumo:
The classic hypothesis of Livingstone and Hubel (1984, 1987) proposed two types of color pathways in primate visual cortex based on recordings from single cells: a segregated, modularpathway that signals color but provides little information about shape or form and a second pathway that signals color differences and so defines forms without the need to specify their colors. A major problem has been to reconcile this neurophysiological hypothesis with the behavioral data. A wealth of psychophysical studies has demonstrated that color vision has orientation-tuned responses and little impairment on form related tasks, but these have not revealed any direct evidence for nonoriented mechanisms. Here we use a psychophysical method of subthreshold summation across orthogonal orientations for isoluminant red-green gratings in monocular and dichoptic viewing conditions to differentiate between nonoriented and orientation-tuned responses to color contrast. We reveal nonoriented color responses at low spatial frequencies (0.25-0.375 c/deg) under monocular conditions changing to orientation-tuned responses at higher spatial frequencies (1.5 c/deg) and under binocular conditions. We suggest that two distinct pathways coexist in color vision at the behavioral level, revealed at different spatial scales: one is isotropic, monocular, and best equipped for the representation of surface color, and the other is orientation-tuned, binocular, and selective for shape and form. This advances our understanding of the organization of the neural pathways involved in human color vision and provides a strong link between neurophysiological and behavioral data. © 2013 ARVO.
Resumo:
The evolution of cognitive neuroscience has been spurred by the development of increasingly sophisticated investigative techniques to study human cognition. In Methods in Mind, experts examine the wide variety of tools available to cognitive neuroscientists, paying particular attention to the ways in which different methods can be integrated to strengthen empirical findings and how innovative uses for established techniques can be developed. The book will be a uniquely valuable resource for the researcher seeking to expand his or her repertoire of investigative techniques. Each chapter explores a different approach. These include transcranial magnetic stimulation, cognitive neuropsychiatry, lesion studies in nonhuman primates, computational modeling, psychophysiology, single neurons and primate behavior, grid computing, eye movements, fMRI, electroencephalography, imaging genetics, magnetoencephalography, neuropharmacology, and neuroendocrinology. As mandated, authors focus on convergence and innovation in their fields; chapters highlight such cross-method innovations as the use of the fMRI signal to constrain magnetoencephalography, the use of electroencephalography (EEG) to guide rapid transcranial magnetic stimulation at a specific frequency, and the successful integration of neuroimaging and genetic analysis. Computational approaches depend on increased computing power, and one chapter describes the use of distributed or grid computing to analyze massive datasets in cyberspace. Each chapter author is a leading authority in the technique discussed.
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* This work was financially supported by the Russian Foundation for Basic Research, project no. 04-01-00858a.
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Medication reconciliation is an important process in reducing medication errors in many countries. Canada, the USA, and UK have incorporated medication reconciliation as a priority area for national patient safety initiatives and goals. The UK national guidance excludes the pediatric population. The aim of this review was to explore the occurrence of medication discrepancies in the pediatric population. The primary objective was to identify studies reporting the rate and clinical significance of the discrepancies and the secondary objective was to ascertain whether any specific interventions have been used for medication reconciliation in pediatric settings. The following electronic bibliographic databases were used to identify studies: PubMed, OVID EMBASE (1980 to 2012 week 1), ISI Web of Science, ISI Biosis, Cumulative Index to Nursing and Allied Health Literature, and OVID International Pharmaceutical Abstracts (1970 to January 2012). Primary studies were identified that observed medication discrepancies in children under 18 years of age upon hospital admission, transfer and discharge, or had reported medication reconciliation interventions. Two independent reviewers screened titles and abstracts for relevant articles and extracted data using pre-defined data fields, including risk of bias assessment. Ten studies were identified with variances in reportage of stage and rate of discrepancies. Studies were heterogeneous in definitions, methods, and patient populations. Most studies related to admissions and reported consistently high rates of discrepancies ranging from 22 to 72.3 % of patients (sample size ranging from 23 to 272). Seven of the studies were low-quality observational studies and three studies were 'grey literature' non-peer reviewed conference abstracts. Studies involving small numbers of patients have shown that medication discrepancies occur at all transitions of care in children. Further research is required to investigate and demonstrate how implementing medication reconciliation can reduce discrepancies and potential patient harm. © 2013 Springer International Publishing Switzerland.
Resumo:
Theory of mind has been defined as the ability to attribute mental sates such as perceptions, knowledge, and belief to others. Studies examining theory of mind in primates have been the center of intense controversy. Much of the research on this subject has focused on designing methodologies to test a primate’s ability to discern the perceptions of others. Namely, many studies have examined an individual’s knowledge of what others can and cannot see. However, other sensory modalities have not undergone as much extensive research. This study aimed to replicate the methodology of a previous experiment with the addition of two novel experimental conditions. Individual long-tailed macaques (Macaca fascicularis) were allowed to approach one of two identical, lidded, clear boxes which had jingle bells attached to them. One of the boxes had the metal bits removed from inside of the jingle bells attached to it, thus creating one “silent” box and leaving the remaining one “noisy”. The experimenter either looked directly at the subject, down at the ground between their knees, or in the novel conditions, turned their back to the subject, or wore a welder’s mask while facing the subject after demonstrating each box’s auditory properties. It was predicted that subjects would choose to approach the silent container in the latter three conditions. The results indicated that subjects selected boxes at random in all conditions. Additionally, in order to explore the possibility of perspective-taking representing a derived trait in the genus Macaca, a phylogeny of the genus was created and annotated to display the presence of perspective-taking as a phenotypic trait in extant species. Three likely evolutionary scenarios leading to the current distribution of perspective-taking are postulated and analyzed for parsimony through the number of assumed gains and losses. The most parsimonious tree suggests that perspective taking could be a conserved trait among the order, giving credence to the argument that some other variable was responsible the negative results in this experiment. It is suggested that the results of the present study represent an artifact of the social environment of the subject population. Moreover, arguments are made for the development of more naturalistic studies for examining mental state attribution in primates.
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Within the main elements of economic sustainability, socio-cultural sustainability, and environmental sustainability, the criteria of 'carrying capacity’ have ben emphasized through residents’ perception analysis to explore practical methods towards the application and implementation of such criteria. As data analysis revealed, the main tourist resources in the case of North Cyprus –the coast and the beach- have a certain capacity to sustain the impact and pressure of tourism. Despite the significance of the indigenous environment and with respect to the residents’ perception of optimum carrying capacity levels, this issue has not been given a due consideration. This has resulted in a process of coastal development which bypasses any measure ore application of a standard to harmonize the degree of physical development and the capacity of the beach. The main objective of this paper is to establish the concept of ‘carrying capacity’ as the means to achieve the reconciliation of environmental impacts with tourism development. The study concludes that, if carrying capacity measurement and its implementation are not incorporated into the planning decision as a clear policy, there will be grave negative consequences for those resources attracting visitors.
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"Once A Catholic" is a novel about the indelible effects of growing up Catholic. The novel is told in a series of stories and poems. The first story, "Credo," offers an overview of the rich culture of Catholicism that binds the Daley family together. "Before The Fall" recalls the safety and warmth of that Catholic faith. Subsequent stories focus on individual family members and events, and the Catholicity that lies at their core. "Holy Orders" tells the story the firstborn male child whose destination is the priesthood. "Finding Ecstasy" is a daughter's story of rebellion through sexual exploration. "Sweet Reconciliation" is the story of a search within oneself for forgiveness, the cornerstone of Catholic upbringing. "Acts of the Apostle" demonstrates the hopelessness of a faith under attack. The final story, "Holy Relics," demonstrates the never-ending desire for redemption and the important act of returning sacredness to its rightful place.
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Washashores was a comic novel exploring the secrets and relationships in a fictional Massachusetts seaside town. Rose Waters, who'd come to Nauset after a failed relationship, encountered two women with a tangled and duplicitous history, and a young autistic savant the women had helped to raise. The boy's uncle, Simon Beadle, once the town drunk, had run away from his past for seventeen years until an event occurred which initiated his journey home. Rose and Simon's paths converged, bringing about complications both whimsical and serious, with events reaching a crisis at the town's Tri-centennial celebration. Here, all that had been hidden was revealed through Rose and Simon's collaborative efforts, and the truth led to reconciliation and the promise of romance. Chapters alternated Rose and Simon's points of view, which permitted the reader to follow their misunderstandings and misreadings of the town and each other.
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Software product line engineering promotes large software reuse by developing a system family that shares a set of developed core features, and enables the selection and customization of a set of variabilities that distinguish each software product family from the others. In order to address the time-to-market, the software industry has been using the clone-and-own technique to create and manage new software products or product lines. Despite its advantages, the clone-and-own approach brings several difficulties for the evolution and reconciliation of the software product lines, especially because of the code conflicts generated by the simultaneous evolution of the original software product line, called Source, and its cloned products, called Target. This thesis proposes an approach to evolve and reconcile cloned products based on mining software repositories and code conflict analysis techniques. The approach provides support to the identification of different kinds of code conflicts – lexical, structural and semantics – that can occur during development task integration – bug correction, enhancements and new use cases – from the original evolved software product line to the cloned product line. We have also conducted an empirical study of characterization of the code conflicts produced during the evolution and merging of two large-scale web information system product lines. The results of our study demonstrate the approach potential to automatically or semi-automatically solve several existing code conflicts thus contributing to reduce the complexity and costs of the reconciliation of cloned software product lines.
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The crisis of the model of technical and formal rationality is discussed in light of a paradigmatic change of the Law that arises in the context of recent transformations of capitalism worldwide, proposing a humanization of Law and Justice with a new ethical-political foundation that promotes a reconciliation between the rules that governs the social order and the world of life, a process of society’s emancipation. As empirical cut it is taken the Right of Children and Youth and, in a practical perspective, the recognition and effectiveness of the Rights of Children and Adolescents in Brazil. It is proposed to analyze the process of democratization and legitimacy of the children and youth rights from the study and apprehension of knowledge that advocate a multidisciplinary view of knowledge and a dialogic praxis for construction of a thought able to contribute to the analysis of public policies and to develop strategies that allow a real change on the social thinking about the doctrine of integral protection of children and adolescents. The proposed methodological approach was developed from a dialectical view of science and as a research strategy for data collection of symbolic cartography or cartographic sociology of law and justice. It is shown that in the process of humanization of the Law and Justice there is a gap between the rights and the democratic participation of these rights.
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It is known that the catecholamine group is constituted by dopamine, noradrenaline and adrenaline, in which the synthesis is regulated by an enzyme named tyrosine hydroxylase. Thus, 3-hydroxytyramine/dopamine (DA) is a precursor of the noradrenaline and adrenaline synthesis and acts as a neurotransmitter in the central nervous system. The three main nuclei, named the retrorubral field (A8 group), the substantia nigra pars compacta (A9 group) and the ventral tegmental area (A10 group), are arranged in the die-mesencephalic portion and are involved in three complexes circuitries - the mesostriatal, mesolimbic and mesocortical pathways. These pathways are related to behavioral manifestations, motricity, learning, reward and pathologies such as Parkinson’s Disease and Schizophrenia. Thus, the aim of this study was to perform de morphological analysis of the A8, A9 and A10 nuclei of the common marmoset (Callithrix jacchus). The marmoset is a neotropical primate, whose morphological and functional characteristics supports the suitability of use of this animal in biomedical research. Coronal sections of the marmoset brain were submitted to cytoarchitectonic characterization and TH-immunohistochemistry. Based on the morphology of the neurons, it was possible to subdivide the A10 group in seven regions: interfascicular nucleus, raphe rostral linear nucleus and raphe caudal linear nucleus, in the middle line; paranigral and parainterfascicular nucleus, in the middle zone; rostral portion of the ventral tegmental area nucleus and parabrachial pigmented nucleus, located in the dorsolateral portion of the mesencephalic tegmentum. A9 group was divided into four regions: substantia nigra compacta dorsal and ventral tiers; substantia nigra compacta lateral and medial clusters. No subdivisions were founded into A8 group. These results revealed that A8, A9 and A10 are phylogenetically conserved between species, but it’s necessary to expand the studies about this compartmentalization, investigating its occurrence in other primate species or investigating its functional relevance.
Resumo:
The software product line engineering brings advantages when compared with the traditional software development regarding the mass customization of the system components. However, there are scenarios that to maintain separated clones of a software system seems to be an easier and more flexible approach to manage their variabilities of a software product line. This dissertation evaluates qualitatively an approach that aims to support the reconciliation of functionalities between cloned systems. The analyzed approach is based on mining data about the issues and source code of evolved cloned web systems. The next step is to process the merge conflicts collected by the approach and not indicated by traditional control version systems to identify potential integration problems from the cloned software systems. The results of the study show the feasibility of the approach to perform a systematic characterization and analysis of merge conflicts for large-scale web-based systems.