DNET: A communications facility for distributed heterogeneous computing

This document describes DNET, a heterogeneous data communications networking facility. DNET allows programs operating on hosts on dissimilar networks to communicate with one another without concern for computer hardware, network protocol, or operating system differences. The overall DNET network is defined as the collection of host machines/networks on which the DNET software is operating. Each underlying network is considered a DNET 'domain'. Data communications service is provided between any two processes on any two hosts on any of the networks (domains) that may be reached via DNET. DNET provides protocol transparent, reliable, streaming data transmission between hosts (restricted, initially to DECnet and TCP/IP networks). DNET also provides variable length datagram service with optional return receipts

Unification of bulk and interface electroresistive switching in oxide systems

We demonstrate that the physical mechanism behind electroresistive switching in oxide Schottky systems is electroformation, as in insulating oxides. Negative resistance shown by the hysteretic current-voltage curves proves that impact ionization is at the origin of the switching. Analyses of the capacitance-voltage and conductance-voltage curves through a simple model show that an atomic rearrangement is involved in the process. Switching in these systems is a bulk effect, not strictly confined at the interface but at the charge space region.Comment: 4 pages, 3 figures, accepted in PR

Tomato ionomic approach for food fortification and safety.

Food fortification is an issue of paramount of importance for people living both in developed and in developing countries. Among substances listed as "nutriceuticals", essential minerals have been recognised for their involvement in several healthy issues, involving all ages. In this frame, food plants are playing a pivotal role since their capability to compartmentalise ions and proteinmetal complexes in edible organs. Conversely, the accumulation of high metal levels in those organs may lead to safety problems. In the recent years, thanks to the availability of new and improved analytical apparatus in both ionic and genomic/transcrittomics areas, it is became feasible to couple data coming from plant physiology and genetics. Ionomics is the discipline that studies the cross-analysis of both data sets. Our group, in the frame of GenoPom project granted by MiUR, is interested to study the ionomics of tomatoes cultivars derived by breeding programmes in which wild relatives have been used to transfer several useful traits, such as resistance to biotic or abiotic stresses, fruit composition and textiture, etc. The introgression of the wild genome into the cultivated one produces new gene combinations. They might lead to the expression of some traits, such as increased or reduced adsorption of some metals and their exclusion or loading into edible organs, thus strongly involving the nutritional food value. Our final goal is to put together data coming from ions homeostasis and gene expression analyses, thus obtaining an ionomic tomato map related to ions absorption, translocation and accumulation in various plant organs, fruits included. To follow our hypothesis, we are studying the ionome of Solanum lycopersicum cv. M82 along with 76 Introgression Lines (ILs) produced by interspecific crosses between this cultivar and the wild species S. pennellii. These ILs are homozygous for small portions of the wild species genome introgressed into the domesticated M82 one. They are used as a useful tool for mapping QTL associated with many traits of interest. It is worthy to note that, until now, little information is available on QTL for ions accumulation in tomato. Moreover, as our knowledge, effects of new gene combinations in introgressed lines on ions uptake related to food safety have not been extensively studied. In this presentation we show results coming from the ionome analysis, carried out on S . lycopersicum M82 and several ILs. Plants were grown in pots in a greenhouse and watered with deionised water Thirty day-old plants were left to grow for 15 days in the presence of non-toxic concentration of Cd, Pb, As, Cr and Zn given combined. Leaves of all plants were then harvested and stored at -80°C for ionome and gene expression analyses. Preliminary results of ionome analysis of S. lycopersicum M82 and several ILs, carried out using an ICP-MS, showed that traits correlated to toxic metals and micronutrients accumulation in apical leaves were significantly modified in response to specific genetic backgrounds. Those results are perhaps due to the introgression of traits linked to uptake, translocation and accumulation of useful and/or toxic metal into plant apical leaves and to interactions of the wild type introgressed genomic regions with the cultivated genome. Also, data are shown on the identification and isolation of Solanum gene sequences related to ions uptake, translocation and accumulation, useful for further real-time gene expression evaluation in both cultivated and ILs during the treatments with the above-mentioned metals

Mechanistic insights on the mode of action of an antiproliferative thiosemicarbazone-nickel complex revealed by an integrated chemogenomic profiling study

Thiosemicarbazones (TSC) and their metal complexes display diverse biological activities and are active against multiple pathological conditions ranging from microbial infections to abnormal cell proliferation. Ribonucleotide reductase (RNR) is considered one of the main targets of TSCs, yet, the existence of additional targets, differently responsible for the multifaceted activities of TSCs and their metal complexes has been proposed. To set the basis for a more comprehensive delineation of their mode of action, we chemogenomically profiled the cellular effects of bis(citronellalthiosemicarbazonato)nickel(II) [Ni(S-tcitr)2] using the unicellular eukaryote Saccharomyces cerevisiae as a model organism. Two complementary genomic phenotyping screens led to the identification of 269 sensitive and 56 tolerant deletion mutant strains and of 14 genes that when overexpressed make yeast cells resistant to an otherwise lethal concentration of Ni(S-tcitr)2. Chromatin remodeling, cytoskeleton organization, mitochondrial function and iron metabolism were identified as lead cellular processes responsible for Ni(S-tcitr)2 toxicity. The latter process, and particularly glutaredoxin-mediated iron loading of RNR, was found to be affected by Ni(S-tcitr)2. Given the multiple pathways regulated by glutaredoxins, targeting of these proteins by Ni(S-tcitr)2 can negatively affect various core cellular processes that may critically contribute to Ni(S-tcitr)2 cytotoxicity

Ion uptake and YSL1 gene identification in tomato

Tomato breeder are using wild tomato relatives, even non-cross compatibles ones, in order to obtain cultivars with highly commercial values bearing new traits. However, the introgression of a wild genome into the cultivated one produces a new gene combinations that may lead to the expression of undeliverable traits, perhaps not so easy to recognise; even more, phenotypic variations may escape during the selection procedure when minor genes or non-abnormal phenotypes are involved. In the frame of the “GenoPom” project funded by MIUR, we have focused our interest on the alteration of heavy metals uptake from the soil and their loading into edible organs in commercial lines coming from Solanum interspecific crosses. Our final aim is to put together data coming from ion homeostasis and gene expression analyses, thus obtaining a ionomic map of tomato. To pursue our goal, we have started to study the cv M82 of Solanum lycopersicon, the wild relative Solanum pennelli and their introgression lines IL. Regarding the experiments on ion homeostasis, S. lycopersicon M82 and the introgression line IL 6-4-2 were grown in hydroponics under controlled environmental conditions. Twenty day-old plants were left to grow for 10 days in the presence of non-toxic concentration of Cd (10 mM), Pb (3 mM), Zn (100 mM) given separately or combined. Control and treated roots and leaves were then harvested and stored at -80°C for ionic and gene expression analyses. Ions analysis of Solanum lycopersicon M82 and IL 6-4-2 showed that traits correlated to ionic homeostasis is significantly modified in response to all metals and to the genotype. The analysis of ions data, obtained by ICP-MS, give a pictures of the different responses performed both to different stress and to combined stress, probably correlated to the up-regulation and/or down regulation of metal uptake proteins. Performed experiments demonstrate that the introgression of the wild genome into the cultivated one produces a new phenotype, perhaps due to the expression of traits linked to uptake, translocation and accumulation of useful and/or toxic metal into plant tissues and organs. Regarding the functional genomics approach for gaining insight into gene networks involved in mineral-ion accumulation in tomato plants, in literature has been reported that at least 25 major family genes are involved for metal homeostasis in plants. Among them, the genes ysl, hma, mtp, znt, zrt have been already studied at least in the plant species Arabidopsis thaliana, A. halleri and Thlaspi caerulescens. So far, no such genes have been reported to be cloned in Solanum species. We have focused our study on the genes YSL1, ZNT1 and MTP1 responsible for uptake, translocation and accumulation of metal such as zinc, cadmium, and iron into plant compartment. For all of them, consensous sequences from nucleotide multialignment have been obtained. Then, each of those were blasted in a Solanum EST collection databank and an assembled UniGene sequence was obtained.. Finally, we have designed primers and performed PCR analysis on S. lycopersicon and S. pennelli genomic DNA. So far, we have cloned a putative ysl1 sequence from tomato, that has shown that a very high percentage of identity (92%) with whole ysl1 gene of Nicotiana tabacum; the in silico translated sequence of this sequence has shown a 89% of identity with the same tobacco protein

Cardiovascular events and treatment of children with high risk medulloblastoma

Background: Children with high-risk medulloblastoma are treated with chemotherapeutic protocols which may affect heart function. We aimed to assesscardiovascular events (CVE) in children with medulloblastoma/primitive neuroectodermal tumors (PNET). Methods: We retrospectively collected data from a case series of 22 children with high-risk medulloblastoma/PNET admitted to the Santobono-Pausilipon Hospital, Naples, Italy from 2008 to 2016. All patients received the Milan HART protocol for high-risk brain malignancies as first line treatment (induction phase), followed by a consolidation phase with Thiotepa and hematopoietic stem cells transplantation, except for 1 patient who received the Milan HART as second line therapy. Four patients also received second line treatment, while 4 patients also received maintenance therapy. Patients underwent cardiac examination, including ECG, echocardiography and serum biomarkers, before antineoplastic treatment initiation and then when clinically needed. Six patients developed CVE (CVE group); 16 patients had no CVE (NO-CVE group). Findings: In the CVE group, 3 patients presented acute CVE during chemotherapy (2 patients with left ventricular (LV) dysfunction, 1 patient with arterial hypertension), while 3 patients presented chronic CVE after chemotherapy completion (2 patients with LV dysfunction, 1 patient with ectopic atrial tachycardia). After a 51 months median follow-up, 9 patients died: 4 from the CVE group (in 2 cases heart failure-related deaths) and 5 from the NO-CVE group (progression of disease). Interpretation: A relevant percentage of children treated for medulloblastoma/PNET develops CVE. Heart failure potentially due to chemotherapy may represent a cause of death. Hence, in these patients, strict cardiac surveillance is essential. Funding: No funding was associated with this study

High-quality all-oxide Schottky junctions fabricated on heavily Nb-doped SrTiO3 substrates

We present a detailed investigation of the electrical properties of epitaxial La0.7Sr0.3MnO3/SrTi0.98Nb0.02O3 Schottky junctions. A fabrication process that allows reduction of the junction dimensions to current electronic device size has been employed. A heavily doped semiconductor has been used as a substrate in order to suppress its series resistance. We show that, unlike standard semiconductors, high-quality oxide-based Schottky junctions maintain a highly rectifying behavior for doping concentration of the semiconductor larger than 10^20 cm^(-3). Moreover, the junctions show hysteretic current-voltage characteristics.Comment: 10 pages, 9 figure

Large microwave generation from d.c. driven magnetic vortex oscillators in magnetic tunnel junctions

Spin polarized current can excite the magnetization of a ferromagnet through the transfer of spin angular momentum to the local spin system. This pure spin-related transport phenomena leads to alluring possibilities for the achievement of a nanometer scale, CMOS compatible and tunable microwave generator operating at low bias for future wireless communications. Microwave emission generated by the persitent motion of magnetic vortices induced by spin transfer effect seems to be a unique manner to reach appropriate spectral linewidth. However, in metallic systems, where such vortex oscillations have been observed, the resulting microwave power is much too small. Here we present experimental evidences of spin-transfer induced core vortex precessions in MgO-based magnetic tunnel junctions with similar good spectral quality but an emitted power at least one order of magnitude stronger. More importantly, unlike to others spin transfer excitations, the thorough comparison between experimental results and models provide a clear textbook illustration of the mechanisms of vortex precessions induced by spin transfer

Cobalt oxide nanoparticles induce oxidative stress and alter electromechanical function in rat ventricular myocytes

Background: Nanotoxicology is an increasingly relevant field and sound paradigms on how inhaled nanoparticles (NPs) interact with organs at the cellular level, causing harmful conditions, have yet to be established. This is particularly true in the case of the cardiovascular system, where experimental and clinical evidence shows morphological and functional damage associated with NP exposure. Giving the increasing interest on cobalt oxide (Co3O4) NPs applications in industrial and bio-medical fields, a detailed knowledge of the involved toxicological effects is required, in view of assessing health risk for subjects/workers daily exposed to nanomaterials. Specifically, it is of interest to evaluate whether NPs enter cardiac cells and interact with cell function. We addressed this issue by investigating the effect of acute exposure to Co3O4-NPs on excitation-contraction coupling in freshly isolated rat ventricular myocytes. Results: Patch clamp analysis showed instability of resting membrane potential, decrease in membrane electrical capacitance, and dose-dependent decrease in action potential duration in cardiomyocytes acutely exposed to Co3O4-NPs. Motion detection and intracellular calcium fluorescence highlighted a parallel impairment of cell contractility in comparison with controls. Specifically, NP-treated cardiomyocytes exhibited a dose-dependent decrease in the fraction of shortening and in the maximal rate of shortening and re-lengthening, as well as a less efficient cytosolic calcium clearing and an increased tendency to develop spontaneous twitches. In addition, treatment with Co3O4-NPs strongly increased ROS accumulation and induced nuclear DNA damage in a dose dependent manner. Finally, transmission electron microscopy analysis demonstrated that acute exposure did lead to cellular internalization of NPs. Conclusions: Taken together, our observations indicate that Co3O4-NPs alter cardiomyocyte electromechanical efficiency and intracellular calcium handling, and induce ROS production resulting in oxidative stress that can be related to DNA damage and adverse effects on cardiomyocyte functionality