Inducing Illusory Ownership of a Virtual Body

We discuss three experiments that investigate how virtual limbs and bodies can come to feel like real limbs and bodies. The first experiment shows that an illusion of ownership of a virtual arm appearing to project out of a person's shoulder can be produced by tactile stimulation on a person's hidden real hand and synchronous stimulation on the seen virtual hand. The second shows that the illusion can be produced by synchronous movement of the person's hidden real hand and a virtual hand. The third shows that a weaker form of the illusion can be produced when a brain–computer interface is employed to move the virtual hand by means of motor imagery without any tactile stimulation. We discuss related studies that indicate that the ownership illusion may be generated for an entire body. This has important implications for the scientific understanding of body ownership and several practical applications

Interactions with Virtual People: Do Avatars Dream of Digital Sheep?

This paper explores another form of artificial entity, ones without physical embodiment. We refer to virtual characters as the name for a type of interactive object that have become familiar in computer games and within virtual reality applications. We refer to these as avatars: three-dimensional graphical objects that are in more-or-less human form which can interact with humans. Sometimes such avatars will be representations of real-humans who are interacting together within a shared networked virtual environment, other times the representations will be of entirely computer generated characters. Unlike other authors, who reserve the term agent for entirely computer generated characters and avatars for virtual embodiments of real people; the same term here is used for both. This is because avatars and agents are on a continuum. The question is where does their behaviour originate? At the extremes the behaviour is either completely computer generated or comes only from tracking of a real person. However, not every aspect of a real person can be tracked every eyebrow move, every blink, every breath rather real tracking data would be supplemented by inferred behaviours which are programmed based on the available information as to what the real human is doing and her/his underlying emotional and psychological state. Hence there is always some programmed behaviour it is only a matter of how much. In any case the same underlying problem remains how can the human character be portrayed in such a manner that its actions are believable and have an impact on the real people with whom it interacts? This paper has three main parts. In the first part we will review some evidence that suggests that humans react with appropriate affect in their interactions with virtual human characters, or with other humans who are represented as avatars. This is so in spite of the fact that the representational fidelity is relatively low. Our evidence will be from the realm of psychotherapy, where virtual social situations are created that do test whether people react appropriately within these situations. We will also consider some experiments on face-to-face virtual communications between people in the same shared virtual environments. The second part will try to give some clues about why this might happen, taking into account modern theories of perception from neuroscience. The third part will include some speculations about the future developments of the relationship between people and virtual people. We will suggest that a more likely scenario than the world becoming populated by physically embodied virtual people (robots, androids) is that in the relatively near future we will interact more and more in our everyday lives with virtual people- bank managers, shop assistants, instructors, and so on. What is happening in the movies with computer graphic generated individuals and entire crowds may move into the space of everyday life

The India-Sri Lanka Free Trade Agreement and the Proposed Comprehensive Economic Partnership Agreement: A Closer Look

The India-Sri Lanka Free Trade Agreement has been in operation for more than a decade. The paper provides the Sri Lankan perspective of the Free Trade Agreement (FTA) highlighting both the positive outcomes and the negative aspects. The paper shows that the FTA has worked in favor of Sri Lanka but its full potential has not yet been realized due to market access problems in India, and the lack of supply capacity for some products in Sri Lanka. The India-Sri Lanka Comprehensive Economic Partnership Agreement addressed many of the negative aspects of the FTA in a broader economic integration framework but was unable come into operation due to public misconceptions and lack of entrepreneurial and political leadership in Sri Lanka

Changing bodies changes minds:owning another body affects social cognition

Research on stereotypes demonstrates how existing prejudice affects the way we process outgroups. Recent studies have considered whether it is possible to change our implicit social bias by experimentally changing the relationship between the self and outgroups. In a number of experimental studies, participants have been exposed to bodily illusions that induced ownership over a body different to their own with respect to gender, age, or race. Ownership of an outgroup body has been found to be associated with a significant reduction in implicit biases against that outgroup. We propose that these changes occur via a process of self association that first takes place in the physical, bodily domain as an increase in perceived physical similarity between self and outgroup member. This self association then extends to the conceptual domain, leading to a generalization of positive self-like associations to the outgroup

Como experimentamos los entornos virtuales inmersivos: el concepto de presencia y su medición

This paper reviews the concept of presence in immersive virtual environments, the sense of being there signalled by people acting and responding realistically to virtual situations and events. We argue that presence is a unique phenomenon that must be distinguished from the degree of engagement, involvement in the portrayed environment. We argue that there are three necessary conditions for presence: the (a) consistent low latency sensorimotor loop between sensory data and proprioception; (b) statistical plausibility: images must be statistically plausible in relation to the probability distribution of images over natural scenes. A constraint on this plausibility is the level of immersion; (c) behaviour-response correlations: Presence may be enhanced and maintained over time by appropriate correlations between the state and behaviour of participants and responses within the environment, correlations that show appropriate responses to the activity of the participants. We conclude with a discussion of methods for assessing whether presence occurs, and in particular recommend the approach of comparison with ground truth and give some examples of this.En este artículo se revisa el concepto de presencia en entornos virtuales inmersivos; es decir, la sensación de estar dentro del entorno virtual indicada por el modo de responder al mismo como si fuera real. La presencia debe distinguirse de otros fenómenos como el compromiso o la implicación. Hay tres condiciones necesarias para la presencia. La primera es un bucle sensomotor consistente y de baja latencia entre los datos sensoriales y propioceptivos. La segunda es la plausibilidad estadística, referente a que las imágenes deben ser estadísticamente plausibles en relación con la distribución de probabilidad de las imágenes en escenas naturales. Un límite para esta condición viene dado por el nivel de inmersión. La tercera es la correlación entre el comportamiento del sujeto y la respuesta del entorno. La presencia se mantiene e incrementa a lo largo del tiempo como consecuencia de la correlación entre, por un lado, el estado y el comportamiento del sujeto y, por otro, las respuestas del entorno, indicando que el entorno responde de forma adecuada a la actividad del sujeto. Se concluye con una discusión de los métodos que se pueden emplear para evaluar la presencia y se recomienda para ello, en particular, la comparación con datos obtenidos sobre el terreno; es decir, la comparación entre las respuestas del sujeto ante estímulos virtuales y las respuestas ante los correspondientes estímulos reales

Developing fertilizer recommendations for rice in Sub-Saharan Africa, achievements and opportunities

Improving agricultural productivity to keep pace with the fast-growing food demand is a huge challenge for sub-Saharan Africa (SSA). Fertilizer is a powerful productivity-enhancing input; nevertheless, farmers of SSA use only 5–9 kg ha−1 of fertilizer, which is ten times lesser than Latin America and Asia (50 and 80 kg ha−1, respectively). Rice (Oryza sativa) is one of the most important food crops of SSA, and its consumption is growing faster than any other commodity in Africa. Rice-based systems have high potential for improving food production through an efficient management of fertilizers. The biophysical environment, cropping systems and socio-economic status of farmers including market opportunities are the main factors for developing appropriate fertilizer recommendations. Many research efforts have been invested in different countries to develop fertilizer recommendation for rice. However, the diversity of rice ecologies, the type and the cost of fertilizers available on local market are the main constraints for development of blanket recommendations of fertilizer usually applied in many countries. Here, we make a reviews of the progress made on the development of fertilizer recommendations for rice-based systems in SSA. The utilization of the new concepts and decisions support tools for development of fertilizer recommendation and the main achievements and weakness are discussed. The opportunities offered by the new concepts, modeling and decision support tools are discussed in a regional strategic approach for better management of fertilizers in the diversified ecologies of rice-based systems

Effect of nitrogen fertilizer on yield and nitrogen use efficiency of four aromatic rice varieties

The objective of this study was to optimize nitrogen fertilizer for higher yield and nitrogen use efficiency of four aromatic rice varieties. Field experiments were conducted at Ndiaye and Fanaye (Senegal) during the hot and dry season 2012 and the wet season 2012 to evaluate the effect of nitrogen on rice yield and nitrogen use efficiency under phosphorus and potassium omission management. Five rates of nitrogen (0, 60, 90, 120 and 150 kg/ha) were associated with P (26 kg P/ha); or P-K (26 kg P/ha and 50 kg K/ha). Four aromatic rice varieties Pusa Basmati, Sahel 329, Sahel 177 and Sahel 328 and a non-aromatic variety Sahel 108 were evaluated. Results showed that across genotypes, rice yield varied from 3.3 to 8.6 Mg/ha under N-P fertilizer and from 3.5 to 8.8 Mg/ha under N-P-K fertilizer at Ndiaye. At Fanaye, rice yield varied from 3.7 to 8.6 Mg/ha under N-P fertilizer and from 3 to 10.3 Mg/ha under N-P-K fertilizer. The highest grain yield was obtained by Sahel 177 among the aromatic rice varieties. The optimum nitrogen dose varied with rice genotype and location. The PFPN and the ANUE were influenced by genotype and varied from 161 to 28 kg grain/kg N and from 105.9 to 0.9 kg grain/kg N, respectively. The highest PFPN was obtained by Sahel 108 followed by Sahel 177. K addition to N-P significantly increased ANUE from 6.4 to 20.78 kg grain/kg N. The aromatic rice variety Sahel 177 is the performing alternative to the non-aromatic rice Sahel 108 in Senegal

Structural changes that accompany the reduced catalytic efficiency of two semisynthetic ribonuclease analogs

The structures of two catalytically defective semi-synthetic RNases obtained by replacing aspartic acid 121 with asparagine or alanine have been determined and refined at a resolution of 2.0 A (R = 0.186 and 0.172, respectively). When these structures are compared with the refined 1.8-A structure (R = 0.204) of the fully active aspartic acid-containing enzyme (Martin, P.D., Doscher, M.S., and Edwards, B. F. P. (1987) J. Biol. Chem. 262, 15930-15938), numerous and widespread changes, much greater in number and magnitude than the small structural variations noted previously between the semisynthetic complex and RNase A, are found to have occurred. These changes include the movement of the loop containing residues 65-72 away from the active site, a more or less generalized relocation of crystallographically bound water molecules, and a number of rearrangements in the hydrogen bonding network at the active site. Most changes are far removed from the immediate site of the modifications and are distributed essentially throughout the molecule. The details of many of these changes are unique to each analog. In the asparagine analog, a destabilization in the positioning of active site residue His-119 also appears to have occurred