Conjunctive Use of Canal Water and Groundwater:An Analysis Based on Farmers’ Practices in Ravangaon, Maharashtra

This article examines what happens when canal water is combined with groundwater. It does so by documenting the complex web of practices that are emerging around accessing, storing and transferring water in the command area of irrigation systems in Ravangaon, a village in Maharashtra, India. From mainly accessing water through field channels that are fed by the public surface irrigation system, farmers have moved to using pumps and siphons to transport water from the canal either directly to their fields or to wells and ponds for storage. Their practices are shaped by hydrogeology – most notably the location and storage capacity of the aquifer in relation to canals and farmers’ plots - as well by the political economy – most notably their relative dependence on water-intensive crops like sugarcane. Access to water has largely become a function of one’s ability to invest in advanced pumping, transporting and storage facilities. In line with other scholars, we conclude that the conjunctive use of canal water and groundwater makes it difficult, if not impossible, to trace and monitor actual water use patterns. This means that water distribution increasingly escapes formal and public forms of regulation and control. The article ends with a reflection on what this means to the advancement of water sustainability and justice.</p

Functional Clustering Drives Encoding Improvement in a Developing Brain Network during Awake Visual Learning

Sensory experience drives dramatic structural and functional plasticity in developing neurons. However, for single-neuron plasticity to optimally improve whole-network encoding of sensory information, changes must be coordinated between neurons to ensure a full range of stimuli is efficiently represented. Using two-photon calcium imaging to monitor evoked activity in over 100 neurons simultaneously, we investigate network-level changes in the developing Xenopus laevis tectum during visual training with motion stimuli. Training causes stimulus-specific changes in neuronal responses and interactions, resulting in improved population encoding. This plasticity is spatially structured, increasing tuning curve similarity and interactions among nearby neurons, and decreasing interactions among distant neurons. Training does not improve encoding by single clusters of similarly responding neurons, but improves encoding across clusters, indicating coordinated plasticity across the network. NMDA receptor blockade prevents coordinated plasticity, reduces clustering, and abolishes whole-network encoding improvement. We conclude that NMDA receptors support experience-dependent network self-organization, allowing efficient population coding of a diverse range of stimuli.Canadian Institutes of Health Researc

I Know My Neighbour: Individual Recognition in Octopus vulgaris

Background: Little is known about individual recognition (IR) in octopuses, although they have been abundantly studied for their sophisticated behaviour and learning capacities. Indeed, the ability of octopuses to recognise conspecifics is suggested by a number of clues emerging from both laboratory studies (where they appear to form and maintain dominance hierarchies) and field observations (octopuses of neighbouring dens display little agonism between each other). To fill this gap in knowledge, we investigated the behaviour of 24 size-matched pairs of Octopus vulgaris in laboratory conditions. Methodology/Principal Findings: The experimental design was composed of 3 phases: Phase 1 (acclimatization): 12 ‘‘sightallowed’’ (and 12 ‘‘isolated’’) pairs were maintained for 3 days in contiguous tanks separated by a transparent (and opaque) partition to allow (and block) the vision of the conspecific; Phase 2 (cohabitation): members of each pair (both sight-allowed and isolated) were transferred into an experimental tank and were allowed to interact for 15 min every day for 3 consecutive days; Phase 3 (test): each pair (both sight-allowed and isolated) was subject to a switch of an octopus to form pairs composed of either familiar (‘‘sham switches’’) or unfamiliar conspecifics (‘‘real switches’’). Longer latencies (i.e. the time elapsed from the first interaction) and fewer physical contacts in the familiar pairs as opposed to the unfamiliar pairs were used as proxies for recognition. Conclusions: Octopuses appear able to recognise conspecifics and to remember the individual previously met for at leas

Design, fabrication and control of soft robots

Conventionally, engineers have employed rigid materials to fabricate precise, predictable robotic systems, which are easily modelled as rigid members connected at discrete joints. Natural systems, however, often match or exceed the performance of robotic systems with deformable bodies. Cephalopods, for example, achieve amazing feats of manipulation and locomotion without a skeleton; even vertebrates such as humans achieve dynamic gaits by storing elastic energy in their compliant bones and soft tissues. Inspired by nature, engineers have begun to explore the design and control of soft-bodied robots composed of compliant materials. This Review discusses recent developments in the emerging field of soft robotics.National Science Foundation (U.S.) (Grant IIS-1226883

Conjunctive Use of Canal Water and Groundwater: An Analysis Based on Farmers’ Practices in Ravangaon, Maharashtra

This article examines what happens when canal water is combined with groundwater. It does so by documenting the complex web of practices that are emerging around accessing, storing and transferring water in the command area of irrigation systems in Ravangaon, a village in Maharashtra, India. From mainly accessing water through field channels that are fed by the public surface irrigation system, farmers have moved to using pumps and siphons to transport water from the canal either directly to their fields or to wells and ponds for storage. Their practices are shaped by hydrogeology – most notably the location and storage capacity of the aquifer in relation to canals and farmers’ plots - as well by the political economy – most notably their relative dependence on water-intensive crops like sugarcane. Access to water has largely become a function of one’s ability to invest in advanced pumping, transporting and storage facilities. In line with other scholars, we conclude that the conjunctive use of canal water and groundwater makes it difficult, if not impossible, to trace and monitor actual water use patterns. This means that water distribution increasingly escapes formal and public forms of regulation and control. The article ends with a reflection on what this means to the advancement of water sustainability and justice

Conjunctive Use of Canal Water and Groundwater: An Analysis Based on Farmers’ Practices in Ravangaon, Maharashtra

This article examines what happens when canal water is combined with groundwater. It does so by documenting the complex web of practices that are emerging around accessing, storing and transferring water in the command area of irrigation systems in Ravangaon, a village in Maharashtra, India. From mainly accessing water through field channels that are fed by the public surface irrigation system, farmers have moved to using pumps and siphons to transport water from the canal either directly to their fields or to wells and ponds for storage. Their practices are shaped by hydrogeology – most notably the location and storage capacity of the aquifer in relation to canals and farmers’ plots - as well by the political economy – most notably their relative dependence on water-intensive crops like sugarcane. Access to water has largely become a function of one’s ability to invest in advanced pumping, transporting and storage facilities. In line with other scholars, we conclude that the conjunctive use of canal water and groundwater makes it difficult, if not impossible, to trace and monitor actual water use patterns. This means that water distribution increasingly escapes formal and public forms of regulation and control. The article ends with a reflection on what this means to the advancement of water sustainability and justice

Design and Development of a Soft Actuator for a Robot Inspired by the Octopus Arm

The octopus provides roboticists with a good example of a completely compliant structure that can however reach good levels of stiffness and then exert forces on its environment. With no rigid structures, the octopus can deform its body and fit small apertures, its arms can bend in all directions and they can even elongate. The peculiar muscular Structure of the octopus arm, named muscular hydrostat, acts in fact as a modifiable skeleton, providing stiffness when and where needed. A key point in imitating this muscular structure is that the muscular hydrostat creates a sort of antagonistic mechanism between different muscle fibres. As a consequence, the arm movements are given by a combination of contractions of part of the muscles and passive stretching of the other muscles. On one side, this reduces the contraction requirements for the single muscle; on the other side, the contractile structure must be compliant and passively stretchable. The contractile units proposed here are built with EAP (Electro-Active Polymer) technology, with a particular geometry that increases the contraction range and force, by using soft materials. Contraction tests on prototypes of the contracting units show a very good similarity with a theoretical model and support the starting hypothesis on the possibility of building a robotic octopus-like arm based on an artificial muscular hydrostat

Design and Development of a Soft Actuator for a Robot Inspired by the Octopus Arm

The octopus provides roboticists with a good example of a completely compliant structure that can however reach good levels of stiffness and then exert forces on its environment. With no rigid structures, the octopus can deform its body and fit small apertures, its arms can bend in all directions and they can even elongate. The peculiar muscular Structure of the octopus arm, named muscular hydrostat, acts in fact as a modifiable skeleton, providing stiffness when and where needed. A key point in imitating this muscular structure is that the muscular hydrostat creates a sort of antagonistic mechanism between different muscle fibres. As a consequence, the arm movements are given by a combination of contractions of part of the muscles and passive stretching of the other muscles. On one side, this reduces the contraction requirements for the single muscle; on the other side, the contractile structure must be compliant and passively stretchable. The contractile units proposed here are built with EAP (Electro-Active Polymer) technology, with a particular geometry that increases the contraction range and force, by using soft materials. Contraction tests on prototypes of the contracting units show a very good similarity with a theoretical model and support the starting hypothesis on the possibility of building a robotic octopus-like arm based on an artificial muscular hydrostat