EcoBot-II: An artificial agent with a natural metabolism

In this paper we report the development of the robot EcoBot-II, which exhibits a primitive form of artificial symbiosis. Microbial Fuel Cells (MFCs) were used as the onboard energy supply, which consisted of bacterial cultures from sewage sludge and employed oxygen from free air for oxidation at the cathode. EcoBot-II was able to perform sensing, information processing, communication and actuation when fed (amongst other substrates) with flies. This is the first robot in the world, to utilise unrefined substrate, oxygen from free air and exhibit four different types of behaviour

VibraTip® durability in clinical practice:How long does it last?

VibraTip® is a battery-powered, disposable, key fob-sized source of vibration used to assess the integrity of vibration perception. To find out how long the device lasts, the stability of its vibration output was measured in response to two usage patterns:- in the first, VibraTip® was subject to 7000 half second activations separated by 2 second rests. This yielded fairly consistent frequency output for the first 6000 activations but an early reduction in amplitude over the first 1000 activations, steadying between 2000 and 6000 activations. in the second, designed to mimic more closely real life clinical usage, runs of ten, half second activations at 2 second intervals were interspersed by 10 minute rests. The cycle was repeated 350 times in all with additional overnight rests to allow electrochemical recovery. VibraTip® performance under these conditions was highly consistent over at least the first 1500 activations, with very little change in vibration frequency even after 3500 discharges. These results indicate that usage patterns markedly affect VibraTip® durability. Rests between ‘patients’ and overnight, characteristic of normal clinical activity, suggests that VibraTip® is likely to provide very consistent performance in the clinical arena for many months of routine use. </jats:p

Autonomous energy harvesting and prevention of cell reversal in MFC stacks

© The Author(s) 2016. This study presents a novel method for avoiding cell reversal whilst optimising energy harvesting from stacked Microbial Fuel Cells (MFCs) by dynamically reconfiguring the electrical connections between them. The sequential changing of in-parallel and in-series electrical connections in an 8-MFC stack resulted in energy being transferred twice as fast into a super-capacitor avoiding cell reversal in MFCs as opposed to a fixed in-series configuration. This approach, allows for a lower internal resistance state within the stack compared to a fixed electrical configuration. This is critical in the initial stages of energy extraction from MFCs connected electrically in-series where the impedance of the capacitor is drawing high levels of current and cell reversals are likely to occur and hinder performance. Automation of electrical connections doubled the extracted power from the stack whilst halving the charging times without any cell reversal occurrence. The electrical reconfiguring of MFCs was performed by a USB-powered switch-box that modulated the stack's connections. This lead to the development of an energy autonomous switch-box circuitry powered solely by the MFC stack with negligible impact on the overall energy harvesting efficiency (i.e. above 90%)

On hybrid circuits exploiting thermistive properties of slime mould

Slime mould Physarum polycephalum is a single cell visible by the unaided eye. Let the slime mould span two electrodes with a single protoplasmic tube: if the tube is heated to approximately ≈40 °C, the electrical resistance of the protoplasmic tube increases from ≈3 Mω to ≈10,000 Mω. The organisms resistance is not proportional nor correlated to the temperature of its environment. Slime mould can therefore not be considered as a thermistor but rather as a thermic switch. We employ the P. polycephalum thermic switch to prototype hybrid electrical analog summator, NAND gates, and cascade the gates into Flip-Flop latch. Computing operations performed on this bio-hybrid computing circuitry feature high repeatability, reproducibility and comparably low propagation delays

Dosage Effects of Cohesin Regulatory Factor PDS5 on Mammalian Development: Implications for Cohesinopathies

Cornelia de Lange syndrome (CdLS), a disorder caused by mutations in cohesion proteins, is characterized by multisystem developmental abnormalities. PDS5, a cohesion protein, is important for proper chromosome segregation in lower organisms and has two homologues in vertebrates (PDS5A and PDS5B). Pds5B mutant mice have developmental abnormalities resembling CdLS; however the role of Pds5A in mammals and the association of PDS5 proteins with CdLS are unknown. To delineate genetic interactions between Pds5A and Pds5B and explore mechanisms underlying phenotypic variability, we generated Pds5A-deficient mice. Curiously, these mice exhibit multiple abnormalities that were previously observed in Pds5B-deficient mice, including cleft palate, skeletal patterning defects, growth retardation, congenital heart defects and delayed migration of enteric neuron precursors. They also frequently display renal agenesis, an abnormality not observed in Pds5B−/− mice. While Pds5A−/− and Pds5B−/− mice die at birth, embryos harboring 3 mutant Pds5 alleles die between E11.5 and E12.5 most likely of heart failure, indicating that total Pds5 gene dosage is critical for normal development. In addition, characterization of these compound homozygous-heterozygous mice revealed a severe abnormality in lens formation that does not occur in either Pds5A−/− or Pds5B−/− mice. We further identified a functional missense mutation (R1292Q) in the PDS5B DNA-binding domain in a familial case of CdLS, in which affected individuals also develop megacolon. This study shows that PDS5A and PDS5B functions other than those involving chromosomal dynamics are important for normal development, highlights the sensitivity of key developmental processes on PDS5 signaling, and provides mechanistic insights into how PDS5 mutations may lead to CdLS

Clinical consistency of vibration sense testing: Development of a manikin great toe with embedded accelerometer for testing and training

Diabetes is the most common cause of peripheral nerve damage and vibration perception is the first sensory modality affected. A standard tuning fork remains the most widely used tool for assessing vibration perception in clinical practice, however inter-operator differences in the use of this tool vary widely. The authors developed a toe manikin capable of reporting the waveform and intensity of vibration imparted to its surface. Using the manikin, the consistency of vibration applied by a group of doctors using a standard 128-Hz tuning fork, with that delivered by the same operator using VibraTip® (McCallan Medical), were compared. Despite differences in technique, the waveform generated with VibraTip was more consistent than that of the tuning fork. With both devices, however, there was considerable intra-operator variability in recorded amplitude and frequency of vibration. By providing instant feedback, the manikin toe serves as a useful training device to encourage consistency of vibration sense testing

EcoBot-II: An artificial agent with a natural metabolism

In this paper we report the development of the robot EcoBot-II, which exhibits a primitive form of artificial symbiosis. Microbial Fuel Cells (MFCs) were used as the onboard energy supply, which consisted of bacterial cultures from sewage sludge and employed oxygen from free air for oxidation at the cathode. EcoBot-II was able to perform sensing, information processing, communication and actuation when fed (amongst other substrates) with flies. This is the first robot in the world, to utilise unrefined substrate, oxygen from free air and exhibit four different types of behaviour