Observations of the inter-ocean exchange around South Africa

There is growing evidence that the interocean exchange south of Africa is an important link in the global overturning circulation of the ocean, the so‐called ocean conveyer belt. At this location, warm and salty Indian Ocean waters enter the South Atlantic and are pulled by currents that eventually reach the North Atlantic, where water cools and sinks. A major contributor to the exchange is the frequent shedding of ring eddies from the termination of the Agulhas Current south of the tip of Africa. This shedding is controlled by developments far upstream in the Indian Ocean, and variations in this ‘Agulhas Leakage’ can lead to changes in the rate and stability of the Atlantic overturning, with possible associated global climate variations [Weijer et al., 1999]. Regional climate variations in the tropical and subtropical Indian Ocean are known to affect the whole system of the Agulhas Current, including the interocean exchanges. This article reports on some of the seminal results of ongoing multinational, multidisciplinary projects that explore these issues.

Vibrationally averaged interatomic distances

Equations are presented for the avereage internuclear distance r(g) and r(a) in terms of elements of the L matrix and the L tensor. These are an alternative to the equations presented by Kuchitsu and Morino.

Inter-laboratory variation of in vitro cumulative gas production profiles of feeds using manual and automated methods

A study was conducted to estimate variation among laboratories and between manual and automated techniques of measuring pressure on the resulting gas production profiles (GPP). Eight feeds (molassed sugarbeet feed, grass silage, maize silage, soyabean hulls, maize gluten feed, whole crop wheat silage, wheat, glucose) were milled to pass a I mm screen and sent to three laboratories (ADAS Nutritional Sciences Research Unit, UK; Institute of Grassland and Environmental Research (IGER), UK; Wageningen University, The Netherlands). Each laboratory measured GPP over 144 h using standardised procedures with manual pressure transducers (MPT) and automated pressure systems (APS). The APS at ADAS used a pressure transducer and bottles in a shaking water bath, while the APS at Wageningen and IGER used a pressure sensor and bottles held in a stationary rack. Apparent dry matter degradability (ADDM) was estimated at the end of the incubation. GPP were fitted to a modified Michaelis-Menten model assuming a single phase of gas production, and GPP were described in terms of the asymptotic volume of gas produced (A), the time to half A (B), the time of maximum gas production rate (t(RM) (gas)) and maximum gas production rate (R-M (gas)). There were effects (P<0.001) of substrate on all parameters. However, MPT produced more (P<0.001) gas, but with longer (P<0.001) B and t(RM gas) (P<0.05) and lower (P<0.001) R-M gas compared to APS. There was no difference between apparatus in ADDM estimates. Interactions occurred between substrate and apparatus, substrate and laboratory, and laboratory and apparatus. However, when mean values for MPT were regressed from the individual laboratories, relationships were good (i.e., adjusted R-2 = 0.827 or higher). Good relationships were also observed with APS, although they were weaker than for MPT (i.e., adjusted R-2 = 0.723 or higher). The relationships between mean MPT and mean APS data were also good (i.e., adjusted R 2 = 0. 844 or higher). Data suggest that, although laboratory and method of measuring pressure are sources of variation in GPP estimation, it should be possible using appropriate mathematical models to standardise data among laboratories so that data from one laboratory could be extrapolated to others. This would allow development of a database of GPP data from many diverse feeds. (c) 2005 Published by Elsevier B.V.

Inter-simple sequence repeat and aggressiveness analyses revealed high genetic diversity, recombination and long-range dispersal in Fusarium culmorum

Inter-simple sequence repeat (ISSR) analysis and aggressiveness assays were used to investigate genetic variability within a global collection of Fusarium culmorum isolates. A set of four ISSR primers were tested, of which three primers amplified a total of 37 bands out of which 30 (81%) were polymorphic. The intraspecific diversity was high, ranging from four to 28 different ISSR genotypes for F. culmorum depending on the primer. The combined analysis of ISSR data revealed 59 different genotypes clustered into seven distinct clades amongst 75 isolates of F. culmorum examined. All the isolates were assayed to test their aggressiveness on a winter wheat cv. 'Armada'. A significant quantitative variation for aggressiveness was found among the isolates. The ISSR and aggressiveness variation existed on a macro- as well as micro-geographical scale. The data suggested a long-range dispersal of F. culmorum and indicated that this fungus may have been introduced into Canada from Europe. In addition to the high level of intraspecific diversity observed in F. culmorum, the index of multilocus association calculated using ISSR data indicated that reproduction in F. culmorum cannot be exclusively clonal and recombination is likely to occur.

Technology sourcing, knowledge management and governance in international inter-organizational innovation networks

This conceptual paper aims to improve our understanding of how internationalised firms use outsourcing and offshoring strategies to manage knowledge and information through the life-cycle of integrated product-service solutions. More precisely, we identify the appropriate theoretical framework for this analysis and investigate through in-depth case studies how UK engineering firms organise, coordinate, and incentivise work that is executed in globally distributed teams. Our research focuses on their UK and India offices to study the organisation and governance of distributed teams. The research has several theoretical dimensions - organization; geography; time and knowledge - that it addresses as boundary challenges.

Robustness of mutual information to inter-subject variability for automatic artefact removal from EEG

The externally recorded electroencephalogram (EEG) is contaminated with signals that do not originate from the brain, collectively known as artefacts. Thus, EEG signals must be cleaned prior to any further analysis. In particular, if the EEG is to be used in online applications such as Brain-Computer Interfaces (BCIs) the removal of artefacts must be performed in an automatic manner. This paper investigates the robustness of Mutual Information based features to inter-subject variability for use in an automatic artefact removal system. The system is based on the separation of EEG recordings into independent components using a temporal ICA method, RADICAL, and the utilisation of a Support Vector Machine for classification of the components into EEG and artefact signals. High accuracy and robustness to inter-subject variability is achieved.

Estimation of distances in virtual environments using size constancy

It is reported in the literature that distances from the observer are underestimated more in virtual environments (VEs) than in physical world conditions. On the other hand estimation of size in VEs is quite accurate and follows a size-constancy law when rich cues are present. This study investigates how estimation of distance in a CAVETM environment is affected by poor and rich cue conditions, subject experience, and environmental learning when the position of the objects is estimated using an experimental paradigm that exploits size constancy. A group of 18 healthy participants was asked to move a virtual sphere controlled using the wand joystick to the position where they thought a previously-displayed virtual cube (stimulus) had appeared. Real-size physical models of the virtual objects were also presented to the participants as a reference of real physical distance during the trials. An accurate estimation of distance implied that the participants assessed the relative size of sphere and cube correctly. The cube appeared at depths between 0.6 m and 3 m, measured along the depth direction of the CAVE. The task was carried out in two environments: a poor cue one with limited background cues, and a rich cue one with textured background surfaces. It was found that distances were underestimated in both poor and rich cue conditions, with greater underestimation in the poor cue environment. The analysis also indicated that factors such as subject experience and environmental learning were not influential. However, least square fitting of Stevens’ power law indicated a high degree of accuracy during the estimation of object locations. This accuracy was higher than in other studies which were not based on a size-estimation paradigm. Thus as indirect result, this study appears to show that accuracy when estimating egocentric distances may be increased using an experimental method that provides information on the relative size of the objects used.

Prosodie et Syndrome de Williams : une étude inter-langue

L’objectif de l’étude est de mieux cerner les particularités acoustiques de la prosodie d’enfants porteurs du SW de langue maternelle anglaise et de langue maternelle française. Des productions spontanées ont été recueillies à l’aide de la tâche de narration « Grenouille, où es-tu ? » (Mayer, 1969). La prosodie des enfants SW est comparée à celle de deux groupes typiques, un de même âge chronologique et un de même âge développemental que le groupe avec SW La population se compose de 1. 7 enfants SW de langue française âgés entre 6 ans et 13 ans 7 mois, appariés à deux groupes typiques et 2. 13 enfants SW de langue anglaise âgés entre 6 ans et 13 ans 11 mois, appariés à deux groupes typiques. Notre analyse porte sur un paramètre acoustique de la prosodie des enfants avec SW : la Variation de la Fréquence Fondamentale. Les résultats sont discutés sur les points suivants : 1. les différences et similitudes entre les profils prosodiques des enfants avec SW et des enfants typiques de même âge chronologique ou développemental, en langue anglaise et en langue française, 2. les différences entre les enfants avec SWde langue maternelle anglaise et les enfants avec SWde langue maternelle française et 3. le développement prosodique observé chez les enfants avec SW. (For English abstract see "Additional Information")