Algebraic synthesis of time-optimal unitaries in SU(2) with alternating controls

We present an algebraic framework to study the time-optimal synthesis of arbitrary unitaries in SU(2), when the control set is restricted to rotations around two non-parallel axes in the Bloch sphere. Our method bypasses commonly used control-theoretical techniques, and easily imposes necessary conditions on time-optimal sequences. In a straightforward fashion, we prove that time-optimal sequences are solely parametrized by three rotation angles and derive general bounds on those angles as a function of the relative rotation speed of each control and the angle between the axes. Results are substantially different whether both clockwise and counterclockwise rotations about the given axes are allowed, or only clockwise rotations. In the first case, we prove that any finite time-optimal sequence is composed at most of five control concatenations, while for the more restrictive case, we present scaling laws on the maximum length of any finite time-optimal sequence. The bounds we find for both cases are stricter than previously published ones and severely constrain the structure of time-optimal sequences, allowing for an efficient numerical search of the time-optimal solution. Our results can be used to find the time-optimal evolution of qubit systems under the action of the considered control set, and thus potentially increase the number of realizable unitaries before decoherence

Expression of different types of [FeFe]-hydrogenase genes in bacteria isolated from a population of a bio-hydrogen pilot-scale plant

[FeFe]-hydrogenases are the enzymes responsible for high yield H 2 production during dark fermentation in bio-hydrogen production plants. The culturable bacterial population present in a pilot-scale plant efficiently producing H2 from waste materials was isolated, classified and identified by means of 16S rDNA gene analysis. The culturable part of the mixed population consists of nine bacterial species that include non-hydrogen producers (Lactobacillus, Enterococcus and Staphylococcus) and several Clostridium that are directly responsible for H2 production. An extensive analysis of the expression of [FeFe]-hydrogenases in the three best producer strains was achieved by RT-PCR, covering the complete set of known genes for each species. This revealed that during H2 production there are several different [FeFe]-hydrogenases simultaneously expressed, with genes belonging to the same phylogenetic and structural classification sharing similar transcriptional profiles. © 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved

Integrated three-dimensional models for noninvasive monitoring and valorization of the Morgantina silver treasure (Sicily)

The Morgantina silver treasure belonging to the Archaeological Museum of Aidone (Sicily) was involved in a three-dimensional (3-D) survey and diagnostics campaign for monitoring the collection over time in anticipation of their temporary transfer to the Metropolitan Museum of Art in New York for a period of 4 years. Using a multidisciplinary approach, a scientific and methodological protocol based on noninvasive techniques to achieve a complete and integrated knowledge of the precious items and their conservation state, as well as to increase their valorization, has been developed. All acquired data, i.e., 3-D models, ultraviolet fluorescence, x-ray images, and chemical information, will be made available, in an integrated way, within a web-oriented platform, which will present an in-progress tool to deepen existing archaeological knowledge and production technologies and to obtain referenced information of the conservation state before and after moving of the collection from its exposure site

From traumatic childhood to cocaine abuse: the critical function of the immune system

Background: Experiencing traumatic childhood is a risk factor for developing substance use disorder (SUD), but the mechanisms that underlie this relationship have not been determined. Adverse childhood experiences affect the immune system and the immune system mediates the effects of psychostimulants. However, whether this system is involved in the etiology of SUD in individuals who have experience early life stress is unknown. Methods:In this study, we performed a series of ex vivo and in vivo experiments in mice and humans to define the function of the immune system in the early-life stress-induced susceptibility to the neurobehavioral effects of cocaine. Results: We provide evidence that exposure to social-stress (S-S) at an early age permanently sensitizes the peripheral (splenocytes) and brain (microglia) immune responses to cocaine in mice. In the brain, microglial activation in the ventral tegmental area (VTA) of S-S mice was associated with functional alterations in dopaminergic neurotransmission, as measured by whole-cell voltage clamp recordings in dopamine (DA) neurons. Notably, preventing immune activation during the S-S exposure reverted the effects of DA in the VTA and the cocaine-induced behavioral phenotype to control levels. In humans, cocaine modulated Toll-like receptor 4-mediated innate immunity, an effect that was enhanced in cocaine addicts who had experienced a difficult childhood. Conclusions Collectively, our findings demonstrate that sensitization to cocaine in early-life-stressed individuals involves brain and peripheral immune responses and that this mechanism is shared between mice and humans

Chemical composition and biological activities of essential oils from Origanum vulgare genotypes belonging to the carvacrol and thymol chemotypes

The remarkable biological activities of oregano essential oils (EOs) have recently prompted a host of studies aimed at exploring their potential innovative applications in the food and pharmaceutical industries. The chemical composition and biological activities of EOs from two Origanum vulgare genotypes, widely cultivated in Sicily and not previously studied for their biological properties, were characterized. Plants of the two genotypes, belonging to the carvacrol (CAR) and thymol (THY) chemotypes and grown in different cultivation environments, were considered for this study. The chemical profiles, including the determination of enantiomeric distribution, of the EOs, obtained by hydrodistillation from dried leaves and flowers, were investigated by GC-MS. Biological activity was evaluated as antimicrobial properties against different pathogen indicator strains, while intestinal barrier integrity, reduction in pathogen adhesion and anti-inflammatory actions were assayed in the intestinal Caco-2 cell line. The chemical profile of the CAR genotype was less complex and characterized by higher levels of the most active compound, i.e., carvacrol, when compared to the THY genotype. The enantiomeric distribution of chiral constituents did not vary across genotypes, while being markedly different from that observed in Origanum vulgare genotypes from other geographical origins. In general, all EOs showed high antimicrobial activity, both in vitro and in a food matrix challenge test. Representative EOs from the two genotypes resulted not altering epithelial monolayer sealing only for concentrations lower than 0.02%, were able to reduce the adhesion of selected pathogens, but did not exert relevant anti-inflammatory effects. These results suggest their potential use as control agents against a wide spectrum of foodborne pathogens

'Omics' and chemical approaches used to monitor iron-deficiency in citrus rootstocks

Two different 'omics' approaches were performed to a better comprehension of biological mechanisms involved in citrus iron (Fe) deficiency. Tips roots from Swingle citrumelo and Carrizo citrange (sensitive and tolerant rootstocks, respectively), growing in pots with control and chlorotic soil, were used for transcriptomic and proteomic analysis. CombiMatrix array was performed to isolate differential genes, among which glutathione peroxidase (GPX), SAUR gene and glutamate dehydrogenase (GDH) showed to be the most involved ones. They were switched on Swingle grown on calcareous conditions compared to Carrizo (in the same soil) and to the same stock in the control soil. The over-expression of GPX could be the effort of plants to neutralize the oxidative environment produced by stress. The involvement of auxin (and as consequence of SAUR gene) in the regulation of Fe deficiency responses is also well known. Both genes were considered in association to peroxidase, ferric chelate reductase activities, iron and chlorophyll content, to monitor the degree of suffering of rootstocks. Among differentially expressed proteins, identified by means of 2D-PAGE and RP-HPLC/nESI-MSMS, a strong down-regulation of cytosolic pyrophosphate-dependent phosphofructokinase β-subunit and NADPH-isocitrate dehydrogenase could produce plant inability to sustain the energetic request of cell roots