Electrophysiological characterization of texture information slip-resistance dependent in the rat vibrissal nerve

<p>Abstract</p> <p>Background</p> <p>Studies in tactile discrimination agree that rats are able to learn a rough-smooth discrimination task by actively touching (whisking) objects with their vibrissae. In particular, we focus on recent evidence of how neurons at different levels of the sensory pathway carry information about tactile stimuli. Here, we analyzed the multifiber afferent discharge of one vibrissal nerve during active whisking. Vibrissae movements were induced by electrical stimulation of motor branches of the facial nerve. We used sandpapers of different grain size as roughness discrimination surfaces and we also consider the change of vibrissal slip-resistance as a way to improve tactile information acquisition. The amplitude of afferent activity was analyzed according to its Root Mean Square value (RMS). The comparisons among experimental situation were quantified by using the information theory.</p> <p>Results</p> <p>We found that the change of the vibrissal slip-resistance is a way to improve the roughness discrimination of surfaces. As roughness increased, the RMS values also increased in almost all cases. In addition, we observed a better discrimination performance in the retraction phase (maximum amount of information).</p> <p>Conclusions</p> <p>The evidence of amplitude changes due to roughness surfaces and slip-resistance levels allows to speculate that texture information is slip-resistance dependent at peripheral level.</p

A precise HST parallax of the cataclysmic variable EX Hydrae, its system parameters, and accretion rate

Using the HST Fine Guidance Sensor, we have measured a high precision astrometric parallax of the cataclysmic variable EX Hydrae, pi=15.50+-0.29mas. From the wavelength-integrated accretion-induced energy flux, we derive a quiescent accretion luminosity for EX Hya of Lacc = (2.6+-0.6)x10e32 erg. The quiescent accretion rate then is Mdot=(6.2\+-1.5)x10e-11 (M1/0.5Msun)^(-1.61})Msun/yr. The time-averaged accretion rate, which includes a small correction for the rare outbursts, is 6% higher. We discuss the system parameters of EX Hya and deduce M1=0.4-0.7Msun, M2=0.07-0.10Msun, and i=76.0deg-77.6deg, using recent radial velocity measurements of both components and restrictions imposed by other observational and theoretical constraints. We conclude that the secondary is undermassive, overluminous, and expanded over a ZAMS star of the same mass. Near the upper limit to M1, the accretion rate of the white dwarf coincides with that due to near-equilibrium angular momentum loss by gravitational radiation and angular momentum transfer from the orbit into the spin-up of the white dwarf. Near the lower mass limit, the correspondingly higher accretion rate requires that either an additional angular momentum loss process is acting besides gravitational radiation or that accretion occurs on a near-adiabatic time scale. The latter possibility would imply that EX Hya is in a transient phase of high mass transfer and the associated spin-up of the white dwarf.Comment: 7 pages A&A-Latex, 1 Figure, accepted for publication in A&

Ecological expected utility and the mythical neural code

Neural spikes are an evolutionarily ancient innovation that remains nature’s unique mechanism for rapid, long distance information transfer. It is now known that neural spikes sub serve a wide variety of functions and essentially all of the basic questions about the communication role of spikes have been answered. Current efforts focus on the neural communication of probabilities and utility values involved in decision making. Significant progress is being made, but many framing issues remain. One basic problem is that the metaphor of a neural code suggests a communication network rather than a recurrent computational system like the real brain. We propose studying the various manifestations of neural spike signaling as adaptations that optimize a utility function called ecological expected utility

Relating industrial symbiosis and circular economy to the sustainable development debate

Industrial Symbiosis (IS) is a business-focused collaborative approach oriented towards resource efficiency that has been theorised and studied mainly over the last twenty-five years. Recently, IS seems to have found a renewed impetus in the framework of the Circular Economy (CE), a novel approach to sustainability and Sustainable Development (SD) that has been rapidly gaining momentum world-wide. This opening chapter of the book provides an introduction to the concepts of IS, CE and SD, and summarizes their complex evolutionary paths, recalling the rel-evant developments and implementation challenges. In addition, the authors point out the divergences and interrelations of these concepts, both among themselves and with other related concepts and research fields, such as industrial ecology, eco-logical modernization and the green economy. Furthermore, the potential contribu-tion of IS and the CE to SD is briefly discussed, also highlighting critical issues and trade-offs, as well as gaps in research and application, especially relating to the so-cial component of sustainability. Particular attention is given to the potential role of IS in the achievement of targets connected to the Sustainable Development Goals set in the UN Agenda 2030. The recent advances in the IS and CE discussion in the context of the SD research community are further explored, with particular empha-sis on the contribution of the International Sustainable Development Research So-ciety (ISDRS) and its 24th annual conference organised in Messina, Italy, in 2018. The programme of that conference, indeed, included specific tracks on the above-mentioned themes, the contents of which are briefly commented on here, after an overview on the whole conference and the main cross-cutting concepts emerged. In the last part of the chapter, a brief description of the chapters collected in the book is presented. These contributions describe and discuss theoretical frameworks, methodological approaches and/or experiences and case studies where IS and the principles of CE are applied in different geographical context and at different scales to ultimately improve the sustainability of the current production patterns

Prediction of outcome in individuals with diabetic foot ulcers: focus on the differences between individuals with and without peripheral arterial disease. The EURODIALE Study

Aims/hypothesis Outcome data on individuals with diabetic foot ulcers are scarce, especially in those with peripheral arterial disease (PAD). We therefore examined the clinical characteristics that best predict poor outcome in a large population of diabetic foot ulcer patients and examined whether such predictors differ between patients with and without PAD. Methods Analyses were conducted within the EURODIALE Study, a prospective cohort study of 1,088 diabetic foot ulcer patients across 14 centres in Europe. Multiple logistic regression modelling was used to identify independent predictors of outcome (i.e. non-healing of the foot ulcer). Results After 1 year of follow-up, 23% of the patients had not healed. Independent baseline predictors of non-healing in the whole study population were older age, male sex, heart failure, the inability to stand or walk without help, end-stage renal disease, larger ulcer size, peripheral neuropathy and PAD. When analyses were performed according to PAD status, infection emerged as a specific predictor of non-healing in PAD patients only. Conclusions/Interpretation Predictors of healing differ between patients with and without PAD, suggesting that diabetic foot ulcers with or without concomitant PAD should be defined as two separate disease states. The observed negative impact of infection on healing that was confined to patients with PAD needs further investigation

Ionic conductivity of an extruded Nafion 1100 EW series of membranes

The proton conductivity of a series of extruded Nafion membranes @of equivalent weight ~EW! of 1100 and nominal dry thickness of 51, 89, 127, and 178 mm# has been studied. Measurements were made in 1 M H2SO4 at 298 K using a four-electrode, dc technique. The membrane area resistance increases with thickness, as expected, from 0.07 to 0.16 V cm2 for Nafion 112 and Nafion 117, respectively. However, in contrast to the published literature, after correcting for the membrane thickness, the conductivity of the membranes decreases with decreasing membrane thickness. For example, values of 0.083 and 0.16 S cm21 were obtained for Nafion 112 and 117 membranes, respectively. In situ current-interrupt measurements in a proton exchange membrane fuel cell confirmed the relatively poor conductivity of the membrane electrode assemblies ~MEAs! based on the thinner membranes. While a high contact resistance to the electrodes may have contributed to the in situ MEA resistance, water balance measurements over the MEA showed that the high resistance was not due to a low water content or to an uneven water distribution in the MEAs. The implications of the findings for the understanding of the membrane properties are discussed