881 resultados para Spatial practices and representations


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The chapter focuses on attempts to change and improve the subjects of the colonial regime in what was the British Protectorate of Tanganyika, contemporary Tanzania. The colonial project in Africa was surrounded by technology, ideology, and representations of modernity based on the application of instrumental rationality. Through the example of colonial practices to control sleeping sickness, it examines how local forms of knowledge and livelihoods were negated and counter-tendencies people generated, offering explanations for the predicament of the human condition consequent upon the colonial experience.

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We present a detailed case study of the characteristics of auroral forms that constitute the first ionospheric signatures of substorm expansion phase onset. Analysis of the optical frequency and along-arc (azimuthal) wave number spectra provides the strongest constraint to date on the potential mechanisms and instabilities in the near-Earth magnetosphere that accompany auroral onset and which precede poleward arc expansion and auroral breakup. We evaluate the frequency and growth rates of the auroral forms as a function of azimuthal wave number to determine whether these wave characteristics are consistent with current models of the substorm onset mechanism. We find that the frequency, spatial scales, and growth rates of the auroral forms are most consistent with the cross-field current instability or a ballooning instability, most likely triggered close to the inner edge of the ion plasma sheet. This result is supportive of a near-Earth plasma sheet initiation of the substorm expansion phase. We also present evidence that the frequency and phase characteristics of the auroral undulations may be generated via resonant processes operating along the geomagnetic field. Our observations provide the most powerful constraint to date on the ionospheric manifestation of the physical processes operating during the first few minutes around auroral substorm onset.

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Perception and action are tightly linked: objects may be perceived not only in terms of visual features, but also in terms of possibilities for action. Previous studies showed that when a centrally located object has a salient graspable feature (e.g., a handle), it facilitates motor responses corresponding with the feature's position. However, such so-called affordance effects have been criticized as resulting from spatial compatibility effects, due to the visual asymmetry created by the graspable feature, irrespective of any affordances. In order to dissociate between affordance and spatial compatibility effects, we asked participants to perform a simple reaction-time task to typically graspable and non-graspable objects with similar visual features (e.g., lollipop and stop sign). Responses were measured using either electromyography (EMG) on proximal arm muscles during reaching-like movements, or with finger key-presses. In both EMG and button press measurements, participants responded faster when the object was either presented in the same location as the responding hand, or was affordable, resulting in significant and independent spatial compatibility and affordance effects, but no interaction. Furthermore, while the spatial compatibility effect was present from the earliest stages of movement preparation and throughout the different stages of movement execution, the affordance effect was restricted to the early stages of movement execution. Finally, we tested a small group of unilateral arm amputees using EMG, and found residual spatial compatibility but no affordance, suggesting that spatial compatibility effects do not necessarily rely on individuals’ available affordances. Our results show dissociation between affordance and spatial compatibility effects, and suggest that rather than evoking the specific motor action most suitable for interaction with the viewed object, graspable objects prompt the motor system in a general, body-part independent fashion

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Aims: While much data exist for the effects of flavonoid-rich foods on spatial memory in rodents, there are no such data for foods/beverages predominantly containing hydroxycinnamates and phenolic acids. To address this, we investigated the effects of moderate Champagne wine intake, which is rich in these components, on spatial memory and related mechanisms relative to the alcohol- and energy-matched controls. Results: In contrast to the isocaloric and alcohol-matched controls, supplementation with Champagne wine (1.78 ml/kg BW, alcohol 12.5% vol.) for 6 weeks led to an improvement in spatial working memory in aged rodents. Targeted protein arrays indicated that these behavioral effects were paralleled by the differential expression of a number of hippocampal and cortical proteins (relative to the isocaloric control group), including those involved in signal transduction, neuroplasticity, apoptosis, and cell cycle regulation. Western immunoblotting confirmed the differential modulation of brain-derived neurotrophic factor, cAMP response-element-binding protein (CREB), p38, dystrophin, 2',3'-cyclic-nucleotide 3'-phosphodiesterase, mammalian target of rapamycin (mTOR), and Bcl-xL in response to Champagne supplementation compared to the control drink, and the modulation of mTOR, Bcl-xL, and CREB in response to alcohol supplementation. Innovation: Our data suggest that smaller phenolics such as gallic acid, protocatechuic acid, tyrosol, caftaric acid, and caffeic acid, in addition to flavonoids, are capable of exerting improvements in spatial memory via the modulation in hippocampal signaling and protein expression. Conclusion: Changes in spatial working memory induced by the Champagne supplementation are linked to the effects of absorbed phenolics on cytoskeletal proteins, neurotrophin expression, and the effects of alcohol on the regulation of apoptotic events in the hippocampus and cortex. Antioxid. Redox Signal. 00, 000-000.

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In order to consider our emotional and physical involvement with film this chapter explores the rapport between camera and performer and how this impacts on the construction of engagement, drawing on critical approaches across the disciplines of film, dance and philosophy to describe our spatial, emotional and sensuous relationship to characters and bodies on-screen. Concern with the relationship between what is happening on screen and the shaping of our engagement is developed through attention to the effort of a particular performance, using close analysis to make sense of the affect invited by qualities of movement and how they are presented in moment from Rosemary’s Baby (Polanski, 1968).

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This article explores the ways that parental death represents a 'vital conjuncture' for Serer young people that reconfigures and potentially transforms intergenerational caring responsibilities in different spatial and temporal contexts. Drawing on semi-structured interviews with young people (aged 15-27), family members, religious and community leaders and professionals in rural and urban Senegal, I explore young people's responses to parental death. 'Continuing bonds' with the deceased were expressed through memories evoked in homespace, shared family practices and gendered responsibilities to 'take care of' bereaved family members, to cultivate inherited farmland and to fulfil the wishes of the deceased. Parental death could reconfigure intergenerational care and lead to shifts in power dynamics, as eldest sons asserted their position of authority. While care-giving roles were associated with agency, the low social status accorded to young women's paid and unpaid domestic work undermined their efforts. The research contributes to understandings of gendered nuances in the experience of bereavement and continuing bonds and provides insight into intra-household decision-making processes, ownership and control of assets. Analysis of the culturally specific meanings of relationships and a young person's social location within hierarchies of gender, age, sibling birth order and wider socio-cultural norms and practices is needed.

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As the fidelity of virtual environments (VE) continues to increase, the possibility of using them as training platforms is becoming increasingly realistic for a variety of application domains, including military and emergency personnel training. In the past, there was much debate on whether the acquisition and subsequent transfer of spatial knowledge from VEs to the real world is possible, or whether the differences in medium during training would essentially be an obstacle to truly learning geometric space. In this paper, the authors present various cognitive and environmental factors that not only contribute to this process, but also interact with each other to a certain degree, leading to a variable exposure time requirement in order for the process of spatial knowledge acquisition (SKA) to occur. The cognitive factors that the authors discuss include a variety of individual user differences such as: knowledge and experience; cognitive gender differences; aptitude and spatial orientation skill; and finally, cognitive styles. Environmental factors discussed include: Size, Spatial layout complexity and landmark distribution. It may seem obvious that since every individual's brain is unique - not only through experience, but also through genetic predisposition that a one size fits all approach to training would be illogical. Furthermore, considering that various cognitive differences may further emerge when a certain stimulus is present (e.g. complex environmental space), it would make even more sense to understand how these factors can impact spatial memory, and to try to adapt the training session by providing visual/auditory cues as well as by changing the exposure time requirements for each individual. The impact of this research domain is important to VE training in general, however within service and military domains, guaranteeing appropriate spatial training is critical in order to ensure that disorientation does not occur in a life or death scenario.

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This paper analyses the impact of several avoided deforestation policies within a patchy forested landscape. Central is the idea that deforestation choices in one area influence deforestation decisions in nearby patches. We explore the interplay between forest landscapes comprising heterogeneous patches, localised spatial displacement, and avoided deforestation policies. Avoided deforestation policies at a landscape level are respectively: two Payments for Environmental Services (PES) policies, one focused on deforestation hotspots, the second being equally available to all agents; a conservation area; and, an agglomeration bonus. We demonstrate how the "best" policy, in terms of reduced leakage, depends on landscape heterogeneity. Agglomeration bonuses are shown to be more effective where there is less landscape heterogeneity, whilst conservation areas are most effective where there is more spatial heterogeneity.

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There is little consensus on how agriculture will meet future food demands sustainably. Soils and their biota play a crucial role by mediating ecosystem services that support agricultural productivity. However, a multitude of site-specific environmental factors and management practices interact to affect the ability of soil biota to perform vital functions, confounding the interpretation of results from experimental approaches. Insights can be gained through models, which integrate the physiological, biological and ecological mechanisms underpinning soil functions. We present a powerful modelling approach for predicting how agricultural management practices (pesticide applications and tillage) affect soil functioning through earthworm populations. By combining energy budgets and individual-based simulation models, and integrating key behavioural and ecological drivers, we accurately predict population responses to pesticide applications in different climatic conditions. We use the model to analyse the ecological consequences of different weed management practices. Our results demonstrate that an important link between agricultural management (herbicide applications and zero, reduced and conventional tillage) and earthworms is the maintenance of soil organic matter (SOM). We show how zero and reduced tillage practices can increase crop yields while preserving natural ecosystem functions. This demonstrates how management practices which aim to sustain agricultural productivity should account for their effects on earthworm populations, as their proliferation stimulates agricultural productivity. Synthesis and applications. Our results indicate that conventional tillage practices have longer term effects on soil biota than pesticide control, if the pesticide has a short dissipation time. The risk of earthworm populations becoming exposed to toxic pesticides will be reduced under dry soil conditions. Similarly, an increase in soil organic matter could increase the recovery rate of earthworm populations. However, effects are not necessarily additive and the impact of different management practices on earthworms depends on their timing and the prevailing environmental conditions. Our model can be used to determine which combinations of crop management practices and climatic conditions pose least overall risk to earthworm populations. Linking our model mechanistically to crop yield models would aid the optimization of crop management systems by exploring the trade-off between different ecosystem services.

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Informed by family language policy (FLP) as the theoretical framework, I illustrate in this paper how language ideologies can be incongruous and language policies can be conflicting through three multilingual families in Singapore representing three major ethnic groups – Chinese, Malay and Indian. By studying their family language audits, observing their language practices, and engaging in conversations about their language ideologies, I look at what these families do and do not do and what they claim to do and not to do. Data were collected over a period of 6 months with more than 700 minutes of recording of actual interactions. Analysis of the data reveals that language ideologies are ‘power-inflected’ and tend to become the source of educational and social tensions which in turn shape family language practices. In Singapore these tensions are illustrated by the bilingual policy recognising mother tongues (MTs) and English as official languages, and its educational policy establishing English as the medium of instruction. The view of English as having instrumental values and MTs as having cultural functions reveals that language choices and practices in family domains are value-laden in everyday interactions and explicitly negotiated and established through FLP.

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Background There is renewed interest in the role played by specific counter-regulatory mechanisms to control the inflammatory host response, poorly investigated in human pathology. Here, we monitored the expression of two anti-inflammatory mediators, annexin 1 and galectin-1, and assessed their potential link to glucocorticoids' (GCs) effective control of nasal polyposis (NP).Methods Total patterns of mRNA and protein expression were analysed by quantitative real-time PCR (qPCR) and Western blotting analyses, whereas ultrastructural immunocytochemistry was used for spatial localization and quantification of each mediator, focusing on mast cells, eosinophils and epithelial cells.Results Up-regulation of the annexin 1 gene, and down-regulation of galectin-1 gene, was detected in polypoid tissue compared with nasal mucosa. Patient treatment with betamethasone augmented galectin-1 protein expression in polyps. At the cellular level, control mast cells and eosinophils displayed higher annexin 1 expression, whereas marked galectin-1 immunolabelling was detected in the granule matrix of mast cells. Cells of glandular duct epithelium also displayed expression of both annexin 1 and galectin-1, augmented after treatment.Conclusion Mast cells and epithelial cells appeared to be pivotal cell types involved in the expression of both annexin 1 and galectin-1. It is possible that annexin 1 and galectin-1 could be functionally associated with a specific mechanism in NP and that GC exert at least part of their beneficial effects on the airway mucosa by up-regulating, in a specific cell target fashion, these anti-inflammatory agonists.

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Husserl left many unpublished drafts explaining (or trying to) his views on spatial representation and geometry, such as, particularly, those collected in the second part of Studien zur Arithmetik und Geometrie (Hua XXI), but no completely articulate work on the subject. In this paper, I put forward an interpretation of what those views might have been. Husserl, I claim, distinguished among different conceptions of space, the space of perception (constituted from sensorial data by intentionally motivated psychic functions), that of physical geometry (or idealized perceptual space), the space of the mathematical science of physical nature (in which science, not only raw perception has a word) and the abstract spaces of mathematics (free creations of the mathematical mind), each of them with its peculiar geometrical structure. Perceptual space is proto-Euclidean and the space of physical geometry Euclidean, but mathematical physics, Husserl allowed, may find it convenient to represent physical space with a non-Euclidean structure. Mathematical spaces, on their turn, can be endowed, he thinks, with any geometry mathematicians may find interesting. Many other related questions are addressed here, in particular those concerning the a priori or a posteriori character of the many geometric features of perceptual space (bearing in mind that there are at least two different notions of a priori in Husserl, which we may call the conceptual and the transcendental a priori). I conclude with an overview of Weyl's ideas on the matter, since his philosophical conceptions are often traceable back to his former master, Husserl.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)