An Evolving and Developing Cellular Electronic Circuit

A novel multi-cellular electronic circuit capable of evolution and development is described here. The circuit is composed of identical cells whose shape and location in the system is arbitrary. Cells all contain the complete genetic description of the final system, as in living organisms. Through a mechanism of development, cells connect to each other using a fully distributed hardware routing mechanism and differentiate by expressing a corresponding part of the genetic code thereby taking a specific functionality and connectivity in the system. The configuration of the system is found by using artificial evolution and intrinsic evolution at the schematic level is possible. Applications include the approximation of boolean functions and the evolution of a controller capable of navigating a Khepera robot while avoiding obstacles. The circuit is suited for a custom chip called POEtic, which is a generic platform to implement bio-inspired applications

A POEtic Architecture for Bio-Inspired Hardware

The implementation of bio-inspired systems in hardware has traditionally been more a matter of artistry than of method. The reasons are multiple, but one of the main problems has always been the lack of a universal platform, of a standardized architecture, and of a proper methodology for the implementation of such systems. The ideas presented in this article are the first results of a new research project, "Reconfigurable POEtic Tissue". The goal of the project is the development of a hardware platform capable of implementing systems inspired by all the three major axes (phylogenesis, ontogenesis, and epigenesis) of bio-inspiration in digital hardware. A novel cellular architecture, capable of exploiting the main features of the future POEtic tissue and compatible with a relatively automatic design methodology, is then presented

Ontogenetic Development and Fault Tolerance in the POEtic Tissue

In this article, we introduce the approach to the realization of ontogenetic development and fault tolerance that will be implemented in the POEtic tissue, a novel reconfigurable digital circuit dedicated to the realization of bio-inspired systems. The modelization in electronic hardware of the developmental process of multi-cellular biological organisms is an approach that could become extremely useful in the implementation of highly complex systems, where concepts such as self-organization and fault tolerance are key issues. The concepts presented in this article represent an attempt at finding a useful set of mechanisms to allow the implementation in digital hardware of a bio-inspired developmental process with a reasonable overhead

FLOWERING REPRESSOR AAA(+) ATPase 1 is a novel regulator of perennial flowering in Arabis alpina

Arabis alpina is a polycarpic perennial, in which PERPETUAL FLOWERING1 (PEP1) regulates flowering and perennial traits in a vernalization-dependent manner. Mutagenesis screens of the pep1 mutant established the role of other flowering time regulators in PEP1-parallel pathways. Here we characterized three allelic enhancers of pep1 (eop002, 085 and 091) which flower early. We mapped the causal mutations and complemented mutants with the identified gene. Using quantitative reverse transcriptase PCR and reporter lines, we determined the protein spatiotemporal expression patterns and localization within the cell. We also characterized its role in Arabidopsis thaliana using CRISPR and in A. alpina by introgressing mutant alleles into a wild-type background. These mutants carried lesions in an AAA(+) ATPase of unknown function, FLOWERING REPRESSOR AAA(+) ATPase 1 (AaFRAT1). AaFRAT1 was detected in the vasculature of young leaf primordia and the rib zone of flowering shoot apical meristems. At the subcellular level, AaFRAT1 was localized at the interphase between the endoplasmic reticulum and peroxisomes. Introgression lines carrying Aafrat1 alleles required less vernalization to flower and reduced number of vegetative axillary branches. By contrast, A. thaliana CRISPR lines showed weak flowering phenotypes. AaFRAT1 contributes to flowering time regulation and the perennial growth habit of A. alpina

Thigh-Derived Inertial Sensor Metrics to Assess the Sit-to-Stand and Stand-to-Sit Transitions in the Timed Up and Go (TUG) Task for Quantifying Mobility Impairment in Multiple Sclerosis

INTRODUCTION: Inertial sensors generate objective and sensitive metrics of movement disability that may indicate fall risk in many clinical conditions including multiple sclerosis (MS). The Timed-Up-And-Go (TUG) task is used to assess patient mobility because it incorporates clinically-relevant submovements during standing. Most sensor-based TUG research has focused on the placement of sensors at the spine, hip or ankles; an examination of thigh activity in TUG in multiple sclerosis is wanting. METHODS: We used validated sensors (x-IMU by x-io) to derive transparent metrics for the sit-to-stand (SI-ST) transition and the stand-to-sit (ST-SI) transition of TUG, and compared effect sizes for metrics from inertial sensors on the thighs to effect sizes for metrics from a sensor placed at the L3 level of the lumbar spine. 23 healthy volunteers were compared to 17 ambulatory persons with MS (PwMS, HAI <= 2). RESULTS: During the SI-ST transition, the metric with the largest effect size comparing healthy volunteers to PwMS was the Area Under the Curve of the thigh angular velocity in the pitch direction -- representing both thigh and knee extension; the peak of the spine pitch angular velocity during SI-ST also had a large effect size, as did some temporal measures of duration of SI-ST, although less so. During the ST-SI transition the metric with the largest effect size in PwMS was the peak of the spine angular velocity curve in the roll direction. A regression was performed. DISCUSSION: We propose for PwMS that the diminished peak angular velocities during SI-ST directly represents extensor weakness, while the increased roll during ST-SI represents diminished postural control. CONCLUSIONS: During the SI-ST transition of TUG, angular velocities can discriminate between healthy volunteers and ambulatory PwMS better than temporal features. Sensor placement on the thighs provides additional discrimination compared to sensor placement at the lumbar spine

Using wearable inertial sensors to compare different versions of the dual task paradigm during walking

The dual task paradigm (DTP), where performance of a walking task co-occurs with a cognitive task to assess performance decrement, has been controversially mooted as a more suitable task to test safety from falls in outdoor and urban environments than simple walking in a hospital corridor. There are a variety of different cognitive tasks that have been used in the DTP, and we wanted to assess the use of a secondary task that requires mental tracking (the alternate letter alphabet task) against a more automatic working memory task (counting backward by ones). In this study we validated the x-io x-IMU wearable inertial sensors, used them to record healthy walking, and then used dynamic time warping to assess the elements of the gait cycle. In the timed 25 foot walk (T25FW) the alternate letter alphabet task lengthened the stride time significantly compared to ordinary walking, while counting backward did not. We conclude that adding a mental tracking task in a DTP will elicit performance decrement in healthy volunteers

Safe cosmetics without animal testing? Contributions of the EU Project Sens-it-iv

The 7th Ammendment to the Cosmetics Directive of the European Commission (Directive 76/768/EEC2) bans the marketing of cosmetics containing animal-tested ingredients since March 2009. Excepted are only tests for repeated dose toxicity, for which the animal ban will come into effect by 2013. One major concern for cosmetics, i.e. the risk of containing skin (contact) sensitizers, has in the past been addressed almost exclusively by animal testing. It is this problem attracting the central interest of the integrated research project Sens-it-iv (Novel Testing Strategies for in vitro Assessment of Allergens, http://www.sens-it-iv.eu), funded by the EC within framework 6 since October 2005. Here, the 28 Sens-it-iv partners from 10 European States present the 5 most promising types of in vitro assays selected for further refinement. These are: (1) a human epidermal equivalent (EE) model to rank contact allergens according to their sensitizing potency, (2) identification of contact sensitizers, including pro-haptens, through intracellular production of IL-18 by the human keratinocyte cell line NCTC 2544, (3) determination of activation markers such as CD86, CD54 and most prominently CXCL8 (IL-8) on/in dendritic cell lines, (4) contact sensitizer-specific migration of MUTZ Langerhans cells towards the chemokine CXCL12, and (5) the allergen-specific activation and proliferation of na\uefve human T cells. Ongoing genomic and proteomic experiments are in the process of identifying larger sensitizer-specific biological marker signatures to be integrated into the above assays. We hope to supply the European control agencies with a basis for further validation of in vitro assays by the end of 2010

Allergic sensitization: screening methods

Experimental in silico, in vitro, and rodent models for screening and predicting protein sensitizing potential are discussed, including whether there is evidence of new sensitizations and allergies since the introduction of genetically modified crops in 1996, the importance of linear versus conformational epitopes, and protein families that become allergens. Some common challenges for predicting protein sensitization are addressed: (a) exposure routes; (b) frequency and dose of exposure; (c) dose-response relationships; (d) role of digestion, food processing, and the food matrix; (e) role of infection; (f) role of the gut microbiota; (g) influence of the structure and physicochemical properties of the protein; and (h) the genetic background and physiology of consumers. The consensus view is that sensitization screening models are not yet validated to definitively predict the de novo sensitizing potential of a novel protein. However, they would be extremely useful in the discovery and research phases of understanding the mechanisms of food allergy development, and may prove fruitful to provide information regarding potential allergenicity risk assessment of future products on a case by case basis. These data and findings were presented at a 2012 international symposium in Prague organized by the Protein Allergenicity Technical Committee of the International Life Sciences Institute’s Health and Environmental Sciences Institute