Gaze Behavior, Believability, Likability and the iCat

The iCat is a user-interface robot with the ability to express a range of emotions through its facial features. This paper summarizes our research whether we can increase the believability and likability of the iCat for its human partners through the application of gaze behaviour. Gaze behaviour serves several functions during social interaction such as mediating conversation flow, communicating emotional information and avoiding distraction by restricting visual input. There are several types of eye and head movements that are necessary for realizing these functions. We designed and evaluated a gaze behaviour system for the iCat robot that implements realistic models of the major types of eye and head movements found in living beings: vergence, vestibulo ocular reflexive, smooth pursuit movements and gaze shifts. We discuss how these models are integrated into the software environment of the iCat and can be used to create complex interaction scenarios. We report about some user tests and draw conclusions for future evaluation scenarios

Insights from Amphioxus into the Evolution of Vertebrate Cartilage

Central to the story of vertebrate evolution is the origin of the vertebrate head, a problem difficult to approach using paleontology and comparative morphology due to a lack of unambiguous intermediate forms. Embryologically, much of the vertebrate head is derived from two ectodermal tissues, the neural crest and cranial placodes. Recent work in protochordates suggests the first chordates possessed migratory neural tube cells with some features of neural crest cells. However, it is unclear how and when these cells acquired the ability to form cellular cartilage, a cell type unique to vertebrates. It has been variously proposed that the neural crest acquired chondrogenic ability by recruiting proto-chondrogenic gene programs deployed in the neural tube, pharynx, and notochord. To test these hypotheses we examined the expression of 11 amphioxus orthologs of genes involved in neural crest chondrogenesis. Consistent with cellular cartilage as a vertebrate novelty, we find that no single amphioxus tissue co-expresses all or most of these genes. However, most are variously co-expressed in mesodermal derivatives. Our results suggest that neural crest-derived cartilage evolved by serial cooption of genes which functioned primitively in mesoderm

Party Wall Behaviour and Impact in QUB and Coheating Tests

In situ measurement can enable accurate evaluation of a building’s as-built performance. However, when measuring whole house performance, party walls introduce measurement uncertainty. Subsequently, it is common to “adjust” measurements to isolate heat transfer through party walls. This study explores the behaviour and impact of party walls in QUB and coheating measurements of a semi-detached house, presenting empirical evidence on the validity of these measurements where a party wall is present. Two different party wall heat transfer behaviours were observed through heat flux density measurements. Thermal charging is apparent in QUB tests and the initial stages of coheating. After 48 h of coheating, the party wall has become heat saturated and exhibits stable heat transfer. Consequently, using heat flux density measurements to isolate party wall heat transfer in QUB tests, where thermal saturation has not been achieved, can result in misleading inferences. The coheating and QUB measurements without party wall adjustment are in close agreement, irrespective of differing heating patterns in the neighbouring property. The generalisation of these findings is problematic since they describe the impact of the case study-specific built form and the test conditions. Future work to explore the impact of built form and test conditions is needed

Convex polygons in Cartesian products

We study several problems concerning convex polygons whose vertices lie in aCartesian product of two sets of n real numbers (for short, grid). First, we prove that everysuch grid contains Ω(log n) points in convex position and that this bound is tight up to aconstant factor. We generalize this result to d dimensions (for a fixed d ∈ N), and obtaina tight lower bound of Ω(logd−1 n) for the maximum number of points in convex positionin a d-dimensional grid. Second, we present polynomial-time algorithms for computing thelongest x- or y-monotone convex polygonal chain in a grid that contains no two points withthe same x- or y-coordinate. We show that the maximum size of a convex polygon with suchunique coordinates can be efficiently approximated up to a factor of 2. Finally, we presentexponential bounds on the maximum number of point sets in convex position in such grids,and for some restricted variants. These bounds are tight up to polynomial factors

Tolerance and safety evaluation of N, N-dimethylglycine, a naturally occurring organic compound, as a feed additive in broiler diets

N,N-dimethylglycine (DMG) is a tertiary amino acid that naturally occurs as an intermediate metabolite in choline-to-glycine metabolism. The objective of the present trial was to evaluate tolerance, safety and bioaccumulation of dietary DMG in broilers when supplemented at 1 g and 10 g Na-DMG/kg. A feeding trial was conducted using 480 1-d-old broiler chicks that were randomly allocated to twenty-four pens and fed one of three test diets added with 0, 1 or 10 g Na-DMG/kg during a 39 d growth period. Production performance was recorded to assess tolerance and efficacy of the supplement. At the end of the trial, toxicity was evaluated by means of haematology, plasma biochemistry and histopathology of liver, kidney and heart (n 12), whereas bioaccumulation was assessed on breast meat, liver, blood, kidney and adipose tissue (n 8). Carcass traits were similar between the control and 1 g Na-DMG/kg feed groups (P.0·05), but the feed:gain ratio was significantly improved at 1 g Na-DMG/kg feed compared with the control or the 10-fold dose (P¼0·008). Histological examinations showed no pathological effects and results of haematology and plasma biochemistry revealed similar values between the test groups (P.0·05). Bioaccumulation occurred at the 10-fold dose, but the resulting DMG content in breast meat was comparable with, for instance, wheat bran and much lower than uncooked spinach. In conclusion, DMG at 1 g Na-DMG/kg improved the feed:gain ratio in broilers without DMG being accumulated in consumer parts. Furthermore, dietary supplementation with DMG up to 10 g Na-DMG/kg did not induce toxicity or impaired performance in broilers

Evaluating Floor Losses in the Context of QUB Measurements of a Passivhaus Dwelling

Measuring the performance of building fabric is increasingly important as stakeholders wish to compare as-built performance with design expectations. When measuring whole house performance (Heat Transfer Coefficient) heat losses through the floor in slab-on-ground type constructions are intractable and introduce uncertainty into measurements. As such efforts are often made to isolate them from measurements. The QUB method is a practical method of measuring whole house building performance. Previous work has shown floor losses can successfully be isolated from measurement through use of heat flux measurements and additional calculation steps. To further test this isolation procedure, three QUB tests were performed on a slab-on-ground Passivhaus dwelling. Whilst the whole house performance measurements agree with the design performance (all results within 11% of the design) the floor losses measured appear unrealistically high. The conditions of the tests, conducted in late summer and in a highly insulated property, are likely causing the heat flux measurements to capture heat being stored in the floor construction rather than heat being lost from the property. Follow up measurements in more preferable conditions are planned which will assist in determining the cause of these observations

Evaluation, contrôle et prévention du risque de transmission du virus influenza aviaire à l'homme

Since mid-december 2003, an epizootic of highly pathogenic avian influenza (type A, sub-type H5N1) occurs in eastern and south-eastern Asia. This epizootic is historically unprecedented in its virulence, geographical spread, and economic consequences for the agricultural sector. Implications for human health were registered in Vietnam and in Thailand. This paper summarizes the current knowledge about the risk evaluation of the transmission of avian influenza virus to humans. The current asian epizootic has highlighted the key role of global health information systems and also the need for exhaustive notification of human and animal cases. It reinforces the concept of veterinary public health

Convex Polygons in Cartesian Products

We study several problems concerning convex polygons whose vertices lie in a Cartesian product of two sets of n real numbers (for short, grid). First, we prove that every such grid contains a convex polygon with Omega(log n) vertices and that this bound is tight up to a constant factor. We generalize this result to d dimensions (for a fixed d in N), and obtain a tight lower bound of Omega(log^{d-1}n) for the maximum number of points in convex position in a d-dimensional grid. Second, we present polynomial-time algorithms for computing the longest convex polygonal chain in a grid that contains no two points with the same x- or y-coordinate. We show that the maximum size of such a convex polygon can be efficiently approximated up to a factor of 2. Finally, we present exponential bounds on the maximum number of convex polygons in these grids, and for some restricted variants. These bounds are tight up to polynomial factors