366 resultados para Postulate


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Global Justice has usually been understood to mean institutional and social justice (political and redistributive issues on a global scale). In contrast, issues involving different national and cultural identities, are usually marginal in reflections on global justice. This occurs despite the fact that human rights include political social and cultural rights. This paper links a conception of global justice, moral cosmopolitanism, with plurinational democracies. After giving a brief description of moral cosmopolitanism I go on to analyse notions of cosmopolitanism and patriotism in Kant's work and the political significance that the notion of "unsocial sociability" and the "Ideas of Pure Reason" of Kant's first Critique have for cosmopolitanism. Finally, I analyse the relationship between cosmopolitanism and minority nations based on the preceding sections. I postulate the need for a moral and institutional refinement of democracies and international society that is better able to accommodate national pluralism than has so far been achieved by traditional liberal constitutionalism and cosmopolitanism

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L'étude a pour objectif de mettre en évidence les effets d'une intervention précoce inspirée des thérapies en Guidance Interactive sur la qualité de l'attachement ainsi que sur la réactivité neuroendocrinienne de stress chez des grands prématurés âgés de 12 mois ainsi que chez leurs mères. La population étudiée comprend 48 grands prématurés (<33 semaines de gestation) et leurs mères. Un programme d'intervention précoce a été proposé aléatoirement à la moitié des dyades incluses dans l'étude. Des mesures de cortisol salivaire ont été effectuées à 12 mois lors d'un épisode de stress modéré (la Situation Étrange) tant chez la mère que chez l'enfant. Les mères ayant bénéficié de l'intervention précoce montrent des taux de cortisol plus élevés que celles n'ayant pas bénéficié de l'intervention. Les auteurs font l'hypothèse que ces mères ont pu développer leur sensibilité envers leur enfant et se montrent, par conséquent, plus concernées lors de l'épisode de stress modéré. The present project aims to assess the effects of an early intervention inspired from Interactive Guidance therapy, on later attachment quality and stress reactivity of prematurely born infants and their mothers. The studied population contends 48 preterm born infants (< 33 weeks og gestational age). Half of the dyads receive an intervention program aiming at promoting the parents' responsivity-sensitivity to infant's cues. Infant's and mother's stress reactivity (salivary cortisol) to mild stressors (Strange Situation) will be assessed at 12 months. Mothers with intervention program show higher cortisol levels than the others. The authors postulate that these mothers enhance their caregiving quality and, subsequently, are more prone to be sensitive to infant's cues and to be concerned during the mild stress episode.

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Résumé Les changements climatiques du Quaternaire ont eu une influence majeure sur la distribution et l'évolution des biota septentrionaux. Les Alpes offrent un cadre spatio-temporel bien étudié pour comprendre la réactivité de la flore et le potentiel d'adaptation d'une espèce végétale face aux changements climatiques. Certaines hypothèses postulent une diversification des espèces en raison de la disparition complète de la flore des Alpes et d'un isolement important des espèces dans des refuges méridionaux durant les dernières glaciations (Tabula Rasa). Une autre hypothèse stipule le maintien de poches de résistance pour la végétation au coeur des Alpes (Nunataks). Comme de nombreuses espèces végétales présentant un grand succès écologique semblent avoir réagi aux glaciations par la multiplication de leur génome (autopolyploïdie), leur étude en milieu naturel devrait permettre de comprendre les avantages inhérents à la polyploïdie. Biscutella laevigata est un modèle emblématique de biogéographie historique, diverses études ayant montré que des populations diploïdes sont actuellement isolées dans les zones restées déglacées durant le dernier maximum glaciaire, alors que des tétraploïdes ont recolonisé l'ensemble des zones alpines mises à nu par le retrait des glaciers. Si le contexte périglaciaire semble avoir favorisé ce jeune complexe autopolyploïde, les circonstances et les avantages de cette mutation génomique ne sont pas encore clairs. Y a-t-il eu de multiples événements de polyploïdisation ? Dans quelle mesure affecte(nt)il(s) la diversité génétique et le potentiel évolutif des polyploïdes ? Les polyploïdes ont-ils une grande flexibilité génomique, favorisant une radiation adaptative, ou doivent-ils leur succès à une grande plasticité écologique ? Cette étude aborde ces questions à différentes échelles spatiales et temporelles. L'échelle régionale des Alpes occidentales permet d'aborder les facteurs distaux (aspects historiques), alors que l'échelle locale cherche à appréhender les facteurs proximaux (mécanismes évolutifs). Dans les Alpes occidentales, des populations ont été densément échantillonnées et étudiées grâce à (1) leur cytotype, (2) leur appartenance taxonomique, (3) leur habitat et (4) des marqueurs moléculaires de l'ADN chloroplastique, en vue d'établir leurs affinités évolutives. Á l'échelle locale, deux systèmes de population ont été étudiés : l'un où les populations persistent en périphérie de l'aire de distribution et l'autre au niveau du front actif de colonisation, en marge altitudinale. Les résultats à l'échelle des Alpes occidentales révèlent les sites d'intérêt (refuges glaciaires, principales barrières et voies de recolonisation) pour une espèce représentative des pelouses alpines, ainsi que pour la biodiversité régionale. Les Préalpes ont joué un rôle important dans le maintien de populations à proximité immédiate des Alpes centrales et dans l'évolution du taxon, voire de la végétation. Il est aussi démontré que l'époque glaciaire a favorisé l'autopolyploïdie polytopique et la recolonisation des Alpes occidentales par des lignées distinctes qui s'hybrident au centre des Alpes, influençant fortement leur diversité génétique et leur potentiel évolutif. L'analyse de populations locales en situations contrastées à l'aide de marqueurs AFLP montre qu'au sein d'une lignée présentant une grande expansion, la diversité génétique est façonnée par des forces évolutives différentes selon le contexte écologique et historique. Les populations persistant présentent une dispersion des gènes restreinte, engendrant une diversité génétique assez faible, mais semblent adaptées aux conditions locales de l'environnement. À l'inverse, les populations colonisant la marge altitudinale sont influencées par les effets de fondation conjugués à une importante dispersion des gènes et, si ces processus impliquent une grande diversité génétique, ils engendrent une répartition aléatoire des génotypes dans l'environnement. Les autopolyploïdes apparaissent ainsi comme capables de persister face aux changements climatiques grâce à certaines facultés d'adaptation locale et de grandes capacités à maintenir une importante diversité génétique lors de la recolonisation post-glaciaire. Summary The extreme climate changes of the Quaternary have had a major influence on species distribution and evolution. The European Alps offer a great framework to investigate flora reactivity and the adaptive potential of species under changing climate. Some hypotheses postulate diversification due to vegetation removal and important isolation in southern refugia (Tabula Rasa), while others explain phylogeographic patterns by the survival of species in favourable Nunataks within the Alps. Since numerous species have successfully reacted to past climate changes by genome multiplication (autopolyploidy), studies of such taxa in natural conditions is likely to explain the ecological success and the advantages of autopolyploidy. Early cytogeographical surveys of Biscutella laevigata have shed light on the links between autopolyploidy and glaciations by indicating that diploids are now spatially isolated in never-glaciated areas, while autotetraploids have recolonised the zones covered by glaciers- during the last glacial maximum. A periglacial context apparently favoured this young autopolyploid complex but the circumstances and the advantages of this genomic mutation remain unclear. What is the glacial history of the B. laevigata autopolyploid complex? Are there multiple events of polyploidisation? To what extent do they affect the genetic diversity and the evolutionary potential of polyploids? Is recolonisation associated with adaptive processes? How does long-term persistence affect genetic diversity? The present study addresses these questions at different spatiotemporal scales. A regional survey at the Western Alps-scale tackles distal factors (evolutionary history), while local-scale studies explore proximal factors (evolutionary mechanisms). In the Western Alps, populations have been densely sampled and studied from the (1) cytotypic, (2) morphotaxonomic, (3) habitat point of views, as well as (4) plastid DNA molecular markers, in order to infer their relationships and establish the maternal lineages phylogeography. At the local scale, populations persisting at the rear edge and populations recolonising the attitudinal margin at the leading edge have been studied by AFLPs to show how genetic diversity is shaped by different evolutionary forces across the species range. The results at the regional scale document the glacial history of a widespread species, representative of alpine meadows, in a regional area of main interest (glacial refugia, main barriers and recolonisation routes) and points out to sites of interest for regional biodiversity. The external Alps have played a major role in the maintenance of populations near the central Alps during the Last Glacial Maximum and influenced the evolution of the species, and of vegetation. Polytopic autopolyploidy in different biogeographic districts is also demonstrated. The species has had an important and rapid radiation because recolonisation took place from different refugia. The subsequent recolonisation of the Western Alps was achieved by independent lineages that are presently admixing in the central Alps. The role of the Pennic summit line is underlined as a great barrier that was permeable only through certain favourable high-altitude passes. The central Alps are thus viewed as an important crossroad where genomes with different evolutionary histories are meeting and admixing. The AFLP analysis and comparison of local populations growing in contrasted ecological and historical situations indicate that populations persisting in the external Alps present restricted gene dispersal and low genetic diversity but seem in equilibrium with their environment. On the contrary, populations colonising the attitudinal margin are mainly influenced by founder effects together with great gene dispersal and genotypes have a nearly random distribution, suggesting that recolonisation is not associated with adaptive processes. Autopolyploids that locally persist against climate changes thus seem to present adaptive ability, while those that actively recolonise the Alps are successful because of their great capacity to maintain a high genetic diversity against founder effects during recolonisation.

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The ability of tumor cells to leave a primary tumor, to disseminate through the body, and to ultimately seed new secondary tumors is universally agreed to be the basis for metastasis formation. An accurate description of the cellular and molecular mechanisms that underlie this multistep process would greatly facilitate the rational development of therapies that effectively allow metastatic disease to be controlled and treated. A number of disparate and sometimes conflicting hypotheses and models have been suggested to explain various aspects of the process, and no single concept explains the mechanism of metastasis in its entirety or encompasses all observations and experimental findings. The exciting progress made in metastasis research in recent years has refined existing ideas, as well as giving rise to new ones. In this review we survey some of the main theories that currently exist in the field, and show that significant convergence is emerging, allowing a synthesis of several models to give a more comprehensive overview of the process of metastasis. As a result we postulate a stromal progression model of metastasis. In this model, progressive modification of the tumor microenvironment is equally as important as genetic and epigenetic changes in tumor cells during primary tumor progression. Mutual regulatory interactions between stroma and tumor cells modify the stemness of the cells that drive tumor growth, in a manner that involves epithelial-mesenchymal and mesenchymal-epithelial-like transitions. Similar interactions need to be recapitulated at secondary sites for metastases to grow. Early disseminating tumor cells can progress at the secondary site in parallel to the primary tumor, both in terms of genetic changes, as well as progressive development of a metastatic stroma. Although this model brings together many ideas in the field, there remain nevertheless a number of major open questions, underscoring the need for further research to fully understand metastasis, and thereby identify new and effective ways of treating metastatic disease.

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Towards an operative analysis of public policies: An approach focused on actors, resources and institutions. This article develops an analytical model which is centred on the individual and collective behaviour of actors involved during different stages of public policy. We postulate that the content and institutional characteristics of public action (dependent variable) are the result of interactions between political-administrative authorities, on the one hand, and, on the other, social groups which cause or suffer the negative effects of a collective problem which public action attempts to resolve (independent variables). The 'game' of the actors depends not only on their particular interests, but also on their resources (money, time, consensus, organization, rights, infrastructure, information, personnel, strength, political support) which they are able to exploit to defend their positions, as well as on the institutional rules which frame these policy games.

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In this paper we analyse the observed systematic differences incosts for teaching hospitals (THhenceforth) in Spain. Concernhas been voiced regarding the existence of a bias in thefinancing of TH s has been raised once prospective budgets arein the arena for hospital finance, and claims for adjusting totake into account the legitimate extra costs of teaching onhospital expenditure are well grounded. We focus on theestimation of the impact of teaching status on average cost. Weused a version of a multiproduct hospital cost function takinginto account some relevant factors from which to derive theobserved differences. We assume that the relationship betweenthe explanatory and the dependent variables follows a flexibleform for each of the explanatory variables. We also model theunderlying covariance structure of the data. We assumed twoqualitatively different sources of variation: random effects andserial correlation. Random variation refers to both general levelvariation (through the random intercept) and the variationspecifically related to teaching status. We postulate that theimpact of the random effects is predominant over the impact ofthe serial correlation effects. The model is estimated byrestricted maximum likelihood. Our results show that costs are 9%higher (15% in the case of median costs) in teaching than innon-teaching hospitals. That is, teaching status legitimatelyexplains no more than half of the observed difference in actualcosts. The impact on costs of the teaching factor depends on thenumber of residents, with an increase of 51.11% per resident forhospitals with fewer than 204 residents (third quartile of thenumber of residents) and 41.84% for hospitals with more than 204residents. In addition, the estimated dispersion is higher amongteaching hospitals. As a result, due to the considerable observedheterogeneity, results should be interpreted with caution. From apolicy making point of view, we conclude that since a higherrelative burden for medical training is under public hospitalcommand, an explicit adjustment to the extra costs that theteaching factor imposes on hospital finance is needed, beforehospital competition for inpatient services takes place.

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We postulate a two-region world, comprised of North (calibrated after the US) and South(calibrated after China). Our optimization results show the compatibility of the following threedesiderata:(1) Global CO2 emissions follow a conservative path that leads to the stabilizationof concentrations at 450 ppm.(2) North and South converge to a path of sustained growth at 1% per year (28.2%per generation) in 2075.(3) During the transition to the steady state, North also grows at 1% per year whileSouth s rates of growth are markedly higher.The transition paths require a drastic reduction of the share of emissions allocated to North,large investments in knowledge, both in North and South, as well as very large investments ineducation in South. Surprisingly, in order to sustain North s utility growth rate, some output mustbe transferred from South to North during the transition.Although undoubtedly subject to many caveats, our results support a degree of optimism byproviding prima facie evidence of the possibility of tackling climate change in a way that is fairboth across generations and across regions while allowing for positive rates of humandevelopment.

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Let there be a positive (exogenous) probability that, at each date, the human species will disappear.We postulate an Ethical Observer (EO) who maximizes intertemporal welfare under thisuncertainty, with expected-utility preferences. Various social welfare criteria entail alternativevon Neumann- Morgenstern utility functions for the EO: utilitarian, Rawlsian, and an extensionof the latter that corrects for the size of population. Our analysis covers, first, a cake-eating economy(without production), where the utilitarian and Rawlsian recommend the same allocation.Second, a productive economy with education and capital, where it turns out that the recommendationsof the two EOs are in general different. But when the utilitarian program diverges, thenwe prove it is optimal for the extended Rawlsian to ignore the uncertainty concerning the possibledisappearance of the human species in the future. We conclude by discussing the implicationsfor intergenerational welfare maximization in the presence of global warming.

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We recently described the neuroimaging and clinical findings in 6 children with cerebellar clefts and proposed that they result from disruptive changes following prenatal cerebellar hemorrhage. We now report an additional series of 9 patients analyzing the clinical and neuroimaging findings. The clefts were located in the left cerebellar hemisphere in 5 cases, in the right in 3, and bilaterally in one child who had bilateral cerebellar hemorrhages as a preterm infant at 30 weeks gestation. In one patient born at 24 weeks of gestation a unilateral cerebellar hemorrhage has been found at the age of 4 months. Other findings included disordered alignment of the folia and fissures, an irregular gray/white matter junction, and abnormal arborization of the white matter in all cases. Supratentorial abnormalities were found in 4 cases. All but 2 patients were born at term. We confirm the distinct neuroimaging pattern of cerebellar clefts. Considering the documented fetal cerebellar hemorrhage in our first series, we postulate that cerebellar clefts usually represent residual disruptive changes after a prenatal cerebellar hemorrhage. Exceptionally, as now documented in 2 patients, cerebellar clefts can be found after neonatal cerebellar hemorrhages in preterm infants. The short-term outcome in these children was variable.

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Sequencing of a fragment of Helicobacter pylori genome led to the identification of two open reading frames showing striking homology with Coenzyme A (CoA) transferases, enzymes catalyzing the reversible transfer of CoA from one carboxylic acid to another. The genes were present in all H. pylori strains tested by polymerase chain reaction or slot blotting but not in Campylobacter jejuni. Genes for the putative A and B subunits of H. pylori CoA-transferase were introduced into the bacterial expression vector pKK223-3 and expressed in Escherichia coli JM105 cells. Amino acid sequence comparisons, combined with measurements of enzyme activities using different CoA donors and acceptors, identified the H. pylori CoA-transferase as a succinyl CoA:acetoacetate CoA-transferase. This activity was consistently observed in different H. pylori strains. Antibodies raised against either recombinant A or B subunits recognized two distinct subunits of Mr approximately 26,000 and 24, 000 that are both necessary for H. pylori CoA-transferase function. The lack of alpha-ketoglutarate dehydrogenase and of succinyl CoA synthetase activities indicates that the generation of succinyl CoA is not mediated by the tricarboxylic acid cycle in H. pylori. We postulate the existence of an alternative pathway where the CoA-transferase is essential for energy metabolism.

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Neuroblastoma (NB) is the most common extracranial malignant tumor in young children and arises at any site of the sympathetic nervous system. The disease exhibits a remarkable phenotypic diversity ranging from spontaneous regression to fatal disease. Poor outcome results from a rapidly progressive, metastatic and drug-resistant disease. Recent studies have suggested that solid tumors may arise from a minor population of cancer stem cells (CSCs) with stem cell markers and typical properties such as self-renewal ability, asymmetric division and drug resistance. In this model, CSCs possess the exclusive ability to initiate and maintain the tumor, and to produce distant metastases. Tumor cell subpopulations with stem-like phenotypes have indeed been identified in several cancer including leukemia, breast, brain and colon cancers. CSC hypothesis still needs to be validated in the other cancers including NB.NB originates from neural crest-derived malignant sympatho-adrenal cells. We have identified rare cells that express markers in conformity with neural crest stem cells and their derived lineages within primary NB tissue and cell lines, leading us to postulate the existence of CSCs in NB tumors.In the absence of specific markers to isolate CSCs, we adapted to NB tumor cells the sphere functional assay, based on the ability of stem cells to grow as spheres in non-adherent conditions. By serial passages of spheres from bone marrow NB metastases, a subset of cells was gradually selected and its specific gene expression profile identified by micro-array time-course analysis. The differentially expressed genes in spheres are enriched in genes implicated in development including CD133, ABC-transporters, WNT and NOTCH genes, identified in others solid cancers as CSCs markers, and other new markers, all referred by us as the Neurosphere Expression Profile (NEP). We confirmed the presence of a cell subpopulation expressing a combination of the NEP markers within a few primary NB samples.The tumorigenic potential of NB spheres was assayed by in vivo tumor growth analyses using orthotopic (adrenal glands) implantations of tumor cells into immune-compromised mice. Tumors derived from the sphere cells were significantly more frequent and were detected earlier compared to whole tumor cells. However, NB cells expressing the neurosphere-associated genes and isolated from the bulk tumors did not recapitulate the CSC-like phenotype in the orthotopic model. In addition, the NB sphere cells lost their higher tumorigenic potential when implanted in a subcutaneous heterotopic in vivo model.These results highlighted the complex behavior of CSC functions and led us to consider the stem-like NB cells as a dynamic and heterogeneous cell population influenced by microenvironment signals.Our approach identified for the first time candidate genes that may be associated with NB self-renewal and tumorigenicity and therefore would establish specific functional targets for more effective therapies in aggressive NB.

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Rational learning theories postulate that information channels and cognitive biases such as individual optimism may influence an individual¿s assessment of the risk of undesired events, especially with regard to those that have a cumulative nature. This is the case with disability in old age, which may take place upon survival to an advanced age, and such factors have been regarded as responsible for certain individual behaviours (for example, the limited incidence of insurance purchase). This paper examines the determinants of individual perceptions with regard to disability in old age and longevity. The cumulative nature of such perceptions of risk is tested, and potential biases are identified, including `optimism¿ and a set of information determinants. Empirical evidence from a representative survey of Catalonia is presented to illustrate these effects. The findings from this research suggest a significant overestimation of disability in old age, yet this is not the case with longevity. Furthermore, individual perceptions with regard to disability in old age, unlike those with regard to longevity, exhibit on aggregate an `optimistic bias¿ and, are perceived as `cumulative risks¿. Gender influences the perceived risk of disability in old age at a population level but not at the individual level, and the opposite holds true for age. Finally, self-reported health status is the main variable behind risk perceptions at both the individual and population level.

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BACKGROUND: Management of ischemic stroke in the presence of aneurysmal brain disease is controversial. Recent retrospective evidence suggests that in selected patients, intravenous thrombolysis (IVT) remains a safe approach for reperfusion. METHODS: We document a case of post-thrombolysis aneurysmal rupture. Supported by additional scientific literature we postulate that acute aneurysmal thrombosis leading to stroke in the culprit artery may be an ominous sign of rupture and should be considered separately from fortuitously discovered distant aneurysmal disease. RESULTS: A 71-year-old female presented with an acute right middle cerebral artery stroke syndrome. IVT allowed vessel reperfusion and revealed a previously concealed, juxtaposed non-giant M1 segment saccular aneurysm. Secondary aneurysmal rupture ensued. The aneurysm was secured by surgical clipping. Postoperative course was uneventful. CONCLUSIONS: This case shows that despite reports of thrombolysis safety in the presence of brain aneurysms, thrombolysis remains potentially hazardous and hints toward an increased risk when the stroke arises on the parent vessel itself.

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We have analyzed the presentation of human histocompatability leukocyte antigen-A*0201-associated tumor peptide antigen MAGE-3271-279 by melanoma cells. We show that specific cytotoxic T lymphocyte (CTL)-recognizing cells transfected with a minigene encoding the preprocessed fragment MAGE-3271-279 failed to recognize cells expressing the full length MAGE-3 protein. Digestion of synthetic peptides extended at the NH2 or COOH terminus of MAGE-3271-279 with purified human proteasome revealed that the generation of the COOH terminus of the antigenic peptide was impaired. Surprisingly, addition of lactacystin to purified proteasome, though partially inhibitory, resulted in the generation of the antigenic peptide. Furthermore, treatment of melanoma cells expressing the MAGE-3 protein with lactacystin resulted in efficient lysis by MAGE-3271-279-specific CTL. We therefore postulate that the generation of antigenic peptides by the proteasome in cells can be modulated by the selective inhibition of certain of its enzymaticactivities.

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Despite myriad studies, neurophysiologic mechanisms mediating illusory contour (IC) sensitivity remain controversial. Among the competing models one favors feed-forward effects within lower-tier cortices (V1/V2). Another situates IC sensitivity first within higher-tier cortices, principally lateral-occipital cortices (LOC), with later feedback effects in V1/V2. Still others postulate that LOC are sensitive to salient regions demarcated by the inducing stimuli, whereas V1/V2 effects specifically support IC sensitivity. We resolved these discordances by using misaligned line gratings, oriented either horizontally or vertically, to induce ICs. Line orientation provides an established assay of V1/V2 modulations independently of IC presence, and gratings lack salient regions. Electrical neuroimaging analyses of visual evoked potentials (VEPs) disambiguated the relative timing and localization of IC sensitivity with respect to that for grating orientation. Millisecond-by-millisecond analyses of VEPs and distributed source estimations revealed a main effect of grating orientation beginning at 65 ms post-stimulus onset within the calcarine sulcus that was followed by a main effect of IC presence beginning at 85 ms post-stimulus onset within the LOC. There was no evidence for differential processing of ICs as a function of the orientation of the grating. These results support models wherein IC sensitivity occurs first within the LOC.