The brain: What is critical about it?

We review the recent proposal that the most fascinating brain properties are related to the fact that it always stays close to a second order phase transition. In such conditions, the collective of neuronal groups can reliably generate robust and flexible behavior, because it is known that at the critical point there is the largest abundance of metastable states to choose from. Here we review the motivation, arguments and recent results, as well as further implications of this view of the functioning brain.Comment: Proceedings of BIOCOMP2007 - Collective Dynamics: Topics on Competition and Cooperation in the Biosciences. Vietri sul Mare, Italy (2007

A new approach to the construction of first-passage-time densities

A new method for constructing first-passage-time probability density functions is outlined. This rests on the possibility of constructing the transition p.d.f. of a new diffusion process in terms of a preassigned transition p.d.f. without making use of the classical space-time transformations of the Kolmogorov equation. A few examples are finally discusse

Uncertainty, Probability, Functionality in contexts of Computational Biology and Bioinformatics

[Abstract] The present paper is dedicated to the cherished memory of Professor José Mira Mira, who prematurely passed away on August 13, 2008. In view of his deep scientific interests and professional expertise in bridging natural versus mechanical computation methods, we offer some remarks on the concepts of uncertainty, probability and functionality with special reference to two areas of particular current interest to researchers in the areas of computational biology and bioinformatics. Preliminarily, a sketch of undergraduate and graduate curricula in Computer Science at Federico II Naples University is provided

A horse, a horse, my kingdom for a horse. Saddle thrombosis of carotid bifurcation in acute stroke

Background: Saddle thrombosis is less frequently detected in carotid arteries than in peripheral arterial embolism. The clot and the distal vessel patency have to be promptly recognized in these cases, because if the carotid vessel is open distally, chances may arise for successful emergent surgical procedures to remove the thrombus. At conventional static imaging, mobile floating thrombi may be difficult to differentiate from thrombosis on carotid complicated lesions of atherosclerotic origin. High-resolution ultrasound (US), with its unique capability of real-time imaging, adds fundamental data for interpretation of the findings. Methods: Carotid ultrasound has been performed in acute stroke patients with high-resolution probes. Real-time clips are analyzed and imaging is presented. Results: Saddle carotid bifurcation thrombosis of cardiac origin has been identified in 2 patients with acute homolateral ischemic stroke, with prompt successful surgical removal in one case. Moreover, an example of a thrombus attached on the ruptured surface of a complicated atherosclerotic plaque in an acute symptomatic stroke patient that was successfully operated in emergency is presented. Conclusions: Early high-resolution ultrasound with real-time imaging can easily identify peculiar characteristics of carotid vulnerable diseases in acute stroke phase. Different clinical implications result from the early identification of these different conditions, modifying the therapeutical strategies. © 2012 Elsevier GmbH

Hemodynamic sensor in cardiac implantable electric devices: the endocardial accelaration technology

There have been substantial progresses in the technology of cardiac implantable electric devices (CIEDs) during the past decades. One of the progresses is represented by the development of a hemodynamic sensor embedded at the tip of a pacing lead that measures myocardial contractility by the analysis of myocardial mechanical vibrations occurring during the cardiac cycle. This sensor, providing continuous hemodynamic monitoring, could play an important role in clinical practice because of several clinical applications in CIEDs recipients. The objectives of this work are to report how this sensor operates and to review the main findings about its clinical applications

Almond diversity and homozygosity define structure, kinship, inbreeding, and linkage disequilibrium in cultivated germplasm, and reveal genomic associations with nut and seed weight

Almond [Prunus dulcis Miller (D.A. Webb)] is the main tree nut species worldwide. Here, genotyping-by-sequencing (GBS) was applied to 149 almond cultivars from the ex situ collections of the Italian Council for Agricultural Research (CREA) and the Spanish National Research Council (CSIC), leading to the detection of 93,119 single-nucleotide polymorphisms (SNPs). The study of population structure outlined four distinct genetic groups and highlighted diversification between the Mediterranean and Californian gene pools. Data on SNP diversity and runs of homozygosity (ROHs) allowed the definition of kinship, inbreeding, and linkage disequilibrium (LD) decay in almond cultivated germplasm. Four-year phenotypic observations, gathered on 98 cultivars of the CREA collection, were used to perform a genome-wide association study (GWAS) and, for the first time in a crop species, homozygosity mapping (HM), resulting in the identification of genomic associations with nut, shell, and seed weight. Both GWAS and HM suggested that loci controlling nut and seed weight are mostly independent. Overall, this study provides insights on the almond cultivation history and delivers information of major interest for almond genetics and breeding. In a broader perspective, our results encourage the use of ROHs in crop science to estimate inbreeding, choose parental combinations minimizing the risk of inbreeding depression, and identify genomic footprints of selection for specific traits

combined effects of deficit irrigation and strobilurin application on gas exchange yield and water use efficiency in tomato solanum lycopersicum l

Abstract Water is the major factor limiting plant productivity in many regions of the world. The aim of this study was to evaluate the combined effect of deficit irrigation (restitution of 100%, 50% and 0% of plant consumption: WR100, WR50 and WR0, respectively) and strobilurin treatment (no agrochemical added vs azoxystrobin treatment) in two tomato genotypes, IT-22/025, a wild-type plant, and Ikram, a commercial hybrid. Water use efficiency (WUE), physiological, yield and quality parameters and the expression of ERD15, a gene involved in abiotic stress response were evaluated. The two genotypes showed a different behaviour in response to water stress. Stomatal conductance decrease from WR100 to WR50 was in mean 27.5% for IT-22/025 and 44.5% for Ikram. Moreover, in Ikram, water stress decreased transpiration more than assimilation rate, while the opposite occurred in IT-22/025. The ERD15 expression decrease from WR100 to WR50 was higher for IT-22/025. These effects corresponded to higher total fresh fruit yield and WUE for IT-22/025. Strobilurin determined lower stomata conductance, maintaining higher assimilation rate, leading to an increase in WUE in WR0. Finally, strobilurin caused an increase in ERD15 expression only in IT-22/025. This study underlines the possibility to reduce the water used in tomato crop, maintaining acceptable yield and quality, by using agronomic and genetic strategy

Resonating Behaviour of Nanomachined Holed Microcantilevers

The nanofabrication of a nanomachined holed structure localized on the free end of a microcantilever is here presented, as a new tool to design micro-resonators with enhanced mass sensitivity. The proposed method allows both for the reduction of the sensor oscillating mass and the increment of the resonance frequency, without decreasing the active surface of the device. A theoretical analysis based on the Rayleigh method was developed to predict resonance frequency, effective mass, and effective stiffness of nanomachined holed microresonators. Analytical results were checked by Finite Element simulations, confirming an increase of the theoretical mass sensitivity up to 250%, without altering other figures of merit. The nanomachined holed resonators were vibrationally characterized, and their Q-factor resulted comparable with solid microcantilevers with same planar dimensions