Design of bidirectional frictional behaviour for tactile contact using ellipsoidal asperity micro-textures

Tactile perception and friction can be modified by producing a deterministic surface topography. Change of surface feature arrangement and texture symmetry can produce an anisotropic frictional behaviour. It is generally achieved through skin hysteresis by promoting its deformation. This work investigates whether a bidirectional friction can be created with microscale ellipsoidal asperity textures, thus relying on the adhesive component of friction. For this purpose, four textured samples with various asperity dimensions were moulded with a silicone rubber having an elastic modulus comparable to that of the skin. Coefficient of friction measurements were conducted in-vivo in two sliding directions with a range of normal loads up to 4 N. Finite element method (FEM) was used to study elastic deformation effects, explain the observed friction difference, and predict surface material influence. Measurements performed perpendicular to the asperity major radii showed consistently higher friction coefficients than that during parallel sliding. For the larger asperity dimensions, a change of the sliding direction increased friction up to a factor of 2. The numerical analysis showed that this effect is mostly related to elastic asperity deflection. Bidirectional friction differences can be further controlled by asperity dimensions, spacing, and material properties.

Bottlenose Dolphin Calf Initiated Pectoral Fin Contact Exchanges with Mother, Other Kin, and Non-Kin

For dolphins, the strongest bond documented is typically that between a mother and her pre-weaned offspring, but outside of the maternal relationship, our knowledge of calf behavior is limited. We examined how 23 bottlenose dolphin (Tursiops truncatus) calves (11 females and 12 males from 9 matrilines) initiated pectoral fin contact (PFC) exchanges with their mothers and kin (n = 362) versus with non-kin (n = 950). Calves initiated PFC exchanges with preferred partners (primarily their mothers) over individuals who were simply available to them. For calves with mothers as their only kin available, there was a difference in how they shared PFC with non-kin adults versus non-kin young. A calf was twice as likely to initiate PFC with an adult (mother or adult non-kin) as with another young dolphin. Male and female calves were different in how they initiated PFC with kin and non-kin, which supports previous research that identified a sex difference in calf behavior. These results support the observation that kin and non-kin dolphins share PFC differently. It is also likely that kin (mothers and calves, siblings, etc.) use other forms of contact to share information and potentially develop their relationships. Understanding all types of tactile contact would facilitate a more detailed understanding of how touch might be used by dolphins when relationships are established and maintained.

Optical-Tactile Sensor for Lump Detection Using Pneumatic Control

Soft tactile sensors are an attractive solution when robotic systems must interact with delicate objects in unstructured and obscured environments, such as most medical robotics applications. The soft nature of such a system increases both comfort and safety, while the addition of simultaneous soft active actuation provides additional features and can also improve the sensing range. This paper presents the development of a compact soft tactile sensor which is able to measure the profile of objects and, through an integrated pneumatic system, actuate and change the effective stiffness of its tactile contact surface. We report experimental results which demonstrate the sensor’s ability to detect lumps on the surface of objects or embedded within a silicone matrix. These results show the potential of this approach as a versatile method of tactile sensing with potential application in medical diagnosis.

Body-Space-Relation in Parkour : Street Practices and Visual Representations

Parkour today is a global subcultural scene that combines street with media practices. Parkour consists of a local moment, fundamentally concerned with the materiality of the street, and simultaneously of a global digital discourse, which involves millions of parkour actors. While the spatial knowledge requires a very close knowledge and tactile contact of the surface’s nature of space, the media representations seem to reflect an opposite image, namely the detachedness of space. In this chapter, I will address the question of space-making and spatial practices in Morocco and the relation to parkour’s visual representations.

Evidence for Maternal Style Among Adult Female Dolphins When Sharing Pectoral Fin Contacts with Their Calves

Adult bottlenose dolphins share pectoral fin contacts (PFC) to manage their social relationships but less is known about how mothers share PFC with their calves. Using a dataset collected over 16 years, we analyzed how 10 matrilines, including three second generation female dolphins in a maternal role, used PFC with their pre-weaned calves. Mothers had different rates of initiation with their calves forming a continuum from those initiating few contacts (15%) to those initiating more (44%). For mothers with all-aged calves, the lateral side was contacted the most to start interactions with mothers contacting body parts at a similar rate. All mothers assumed the same posture regardless of their role as initiator or receiver, with horizontal the most prevalent posture. Two maternal styles were found for PFC: high and low use of PFC. Within the high PFC group, there was individual variation that was related to calf sex. Even though evidence of maternal style was confirmed in PFC exchanges between adult female dolphins and their calves, the number of PFC shared between these kin was only ~9% of all documented PFC contacts (N = 4,345) over 16 years, suggesting that other forms of tactile contact may be more important within the confines of the mother-offspring relationship in delphinids.

Features of teaching swimming to children of primary school age with autism spectrum disorder

The article presents an analysis of the peculiarities of teaching swimming to children of primary school age with autism spectrum disorder. The study was conducted on the basis of the sports complex “Burevestnik” in Kazan. According to the results of testing on the scale of assessment of the degree of autism of children, a group of boys aged 9-10 years was formed. In four children, the degree of autism is not expressed and moderately pronounced, in one child-a severe form of autism. At the time of the examination, the children did not know how to swim. Classes on the water were held for six months 3 times a week for 40 minutes. The children trained using the author’s equipment – special boards with an associative character (a fish with bubbles, a whale with a fountain, a dolphin, a frog, a turtle, a rocket). The size of the swimming board remained standard, 32x25cm. The development of the supporting device was due to the need to eliminate the inadequate response to various sensory stimuli, such as touching strangers or tactile contact with unfamiliar objects and textures, as well as to obtain positive associations and mental images for the successful development of a new exercise. At the end of six months of classes, all children with autism spectrum disorder have mastered swimming training according to the indicators: 1) immersion in water with exhalation in water, 2) sliding on the chest with the movement of the legs, 3) sliding on the chest with the movement of the legs and performing proper breathing. The study was determined by the ability to use boards to swim copyright form associative nature.

98 Impact of social mixing on feedlot steer eating and lying behavior

This study evaluated the impact of mixing cattle from two sources of feedlot steers (n = 96) on feeding and lying behavior. Angus crossbred steers (n = 48 McG and n = 48 BCS), similar in genetic composition, were transported (833.64 ± 85.29 km) to a feedlot 39-d prior to mixing where the two sources were housed without visual or tactile contact. Steers, blocked by source and stratified by d -34 body weight, were randomly assigned to one of 12 pens (n = 8 steers/pen) for the 42-d study. Pens were assigned to one of two treatments (n = 6 pens/treatment): 1) NOMIX—100% of cattle from McG (n = 3 pens) or BCS (n = 3 pens) and, 2) MIX—50% of cattle from BCS and 50% from McG (n = 6 pens). Instantaneous scan sampling (n = 61 scans/d; 10 min intervals) recorded the number of steers per pen eating and lying on d1, 2, 3, 4, 5, 6, 7, 8, 9, 14, 15, 16, 21, 22, 23, 28, 29, 36, and 37 after mixing. Proportion of steers lying varied across time (P < 0.0001); however, a greater proportion of steers laid down on d1 compared to d7, 8, 9, 16, and 28 (P < 0.03). The proportion of steers observed eating increased over time (P < 0.0001). Fewer steers ate on d1 than d9, 14, 15, 28, 29, and 36 (all P < 0.01). More steers were observed eating on d8 and 16 than the first seven days (all P < 0.01) and on d37 than the first 6 days (all P < 0.02). While there was no impact of mixing, data indicate that handling and sorting cattle into new pens impacts eating and lying behavior and it takes approximately a week for behavior to stabilize.

99 Impact of social mixing on feedlot steer eating and lying behavior

This study evaluated the impact of mixing cattle from two sources of feedlot steers (n = 96) on feeding and lying behavior. Angus crossbred steers (n = 48 McG and n = 48 BCS), similar in genetic composition, were transported (833.64 ± 85.29 km) to a feedlot 39-d prior to mixing where the two sources were housed without visual or tactile contact. Steers, blocked by source and stratified by d -34 body weight, were randomly assigned to one of 12 pens (n = 8 steers/pen) for the 42-d study. Pens were assigned to one of two treatments (n = 6 pens/treatment): 1) NOMIX—100% of cattle from McG (n = 3 pens) or BCS (n = 3 pens) and, 2) MIX—50% of cattle from BCS and 50% from McG (n = 6 pens). Instantaneous scan sampling (n = 61 scans/d; 10 min intervals) recorded the number of steers per pen eating and lying on d1, 2, 3, 4, 5, 6, 7, 8, 9, 14, 15, 16, 21, 22, 23, 28, 29, 36, and 37 after mixing. Proportion of steers lying varied across time (P < 0.0001); however, a greater proportion of steers laid down on d1 compared to d7, 8, 9, 16, and 28 (P < 0.03). The proportion of steers observed eating increased over time (P < 0.0001). Fewer steers ate on d1 than d9, 14, 15, 28, 29, and 36 (all P < 0.01). More steers were observed eating on d8 and 16 than the first seven days (all P < 0.01) and on d37 than the first 6 days (all P < 0.02). While there was no impact of mixing, data indicate that handling and sorting cattle into new pens impacts eating and lying behavior and it takes approximately a week for behavior to stabilize.

Increase in Salivary Oxytocin Levels in Mothers After Tactile Contact Between Adiaper-like Nonwoven Sheet With Large Projectionsand the Palm: A Pilot Study

ObjectiveThe aim of this pilot study was to investigate whether or not tactile contact between a diaper-like nonwoven sheet with specific physical characteristics and the palm of the hand would increase the maternal level ofoxytocinwhich is one of the neuropeptides promoting formation of the mother-infant bond.ResultsTen healthy non-breastfeeding Japanese mothers were enrolled in this pilot study. We prepared diaper-like nonwoven sheets with large or small projections. Physical indices related to softness and fluffiness were higher in the sheet with large projections than in the sheet with small projections. Salivary oxytocin levels in the motherswere increasedafter tactile contact with thesheet with large projections, but not after contact with the sheet with small projections. This pilot study suggests that maternal oxytocin levels are increased by tactile contact between a soft and fluffy diaper sheet and the palm.

Effect of Covering a Visitor Viewing Area Window on the Behaviour of Zoo-Housed Little Penguins (Eudyptula minor)

Studies on the effects of visitors on zoo animals have shown mixed findings and as a result, the manner in which visitors affect zoo animals remains unclear for many species, including a rarely studied taxa such as penguins. Penguins are a common zoo-housed species and have been shown to display huddling, vigilance and avoidance towards zoo visitors which can be indicative of fear. Here, we examined the effects of covering one visitor viewing area window, out of four, on little penguin (Eudyptula minor) behaviours that may be indicative of fear. Two treatments were randomly imposed on different days: (1) The main visitor viewing area window, where most visitor-penguin interactions occurred, was uncovered (‘Main window uncovered’) and (2) The main visitor viewing area window was covered (‘Main window covered’). Penguin numbers and behaviour were recorded near the main visitor viewing area window and the three other visitor viewing area windows, as well as one area not visible to visitors (‘Corner’ area). Furthermore, visitor numbers and visitor behaviour were recorded at all four visitor viewing area windows. Covering the main visitor viewing area window reduced the proportion of visitors present at this window by about 85% (p < 0.001) and reduced potentially threatening visitor behaviours at this window such as tactile contact with the window, loud vocalisations and sudden movement (p < 0.05). When the main visitor viewing area window was covered, the proportion of penguins present increased by about 25% (p < 0.05), the proportion of visible penguins preening in the water increased by about 180% (p < 0.05) and the proportion of visible penguins vigilant decreased by about 70% (p < 0.05) in the area near this main window. A preference for the Corner area was also found whereby 59% and 49% of penguins were present in this area when the main window was uncovered and covered, respectively. These results provide limited evidence that the little penguins in this exhibit showed an aversion to the area near the main visitor viewing area window when it was uncovered based on the increased avoidance and vigilance and decreased preening in the water in this area. This suggests visitors may be fear-provoking for these little penguins. However, it is unclear whether visual contact with visitors per se or other aspects of visitor contact, such as visitor-induced sounds and vibrations, were responsible for this apparent aversion when this window was uncovered.