Three-dimensional evolution of magnetic and velocity shear driven instabilities in a compressible magnetized jet

The problem of three-dimensional combined magnetic and velocity shear driven instabilities of a compressible magnetized jet modeled with a plane neutral/current double vortex sheet in the framework of the resistive magnetohydrodynamics is addressed. The resulting dynamics given by the stream+current sheet interaction is analyzed and the effects of a variable geometry of the basic fields are considered. Depending on the basic asymptotic magnetic field configuration, a selection rule of the linear instability modes can be obtained. Hence, the system follows a two-stage path developing either through a fully three-dimensional dynamics with a rapid evolution of kink modes leading to a final turbulent state, or rather through a driving two-dimensional instability pattern that develops on parallel planes on which a reconnection+coalescence process takes place.Comment: 33 pages, 15 figures, accepted for publication in Physics of Plasma

The Concept of a Noncommutative Riemann Surface

We consider the compactification M(atrix) theory on a Riemann surface Sigma of genus g>1. A natural generalization of the case of the torus leads to construct a projective unitary representation of pi_1(\Sigma), realized on the Hilbert space of square integrable functions on the upper half--plane. A uniquely determined gauge connection, which in turn defines a gauged sl_2(R) algebra, provides the central extension. This has a geometric interpretation as the gauge length of a geodesic triangle, and corresponds to a 2-cocycle of the 2nd Hochschild cohomology group of the Fuchsian group uniformizing Sigma. Our construction can be seen as a suitable double-scaling limit N\to\infty, k\to-\infty of a U(N) representation of pi_1(Sigma), where k is the degree of the associated holomorphic vector bundle, which can be seen as the higher-genus analog of 't Hooft's clock and shift matrices of QCD. We compare the above mentioned uniqueness of the connection with the one considered in the differential-geometric approach to the Narasimhan-Seshadri theorem provided by Donaldson. We then use our infinite dimensional representation to construct a C^\star-algebra which can be interpreted as a noncommutative Riemann surface Sigma_\theta. Finally, we comment on the extension to higher genus of the concept of Morita equivalence.Comment: 1+16 pages, LaTe

CO2-Induced Transcriptional Reorganization: Molecular Basis of Capnophillic Lactic Fermentation in Thermotoga neapolitana

Capnophilic lactic fermentation (CLF) is a novel anaplerotic pathway able to convert sugars to lactic acid (LA) and hydrogen using CO2 as carbon enhancer in the hyperthermophilic bacterium Thermotoga neapolitana. In order to give further insights into CLF metabolic networks, we investigated the transcriptional modification induced by CO2 using a RNA-seq approach. Transcriptomic analysis revealed 1601 differentially expressed genes (DEGs) in an enriched CO2 atmosphere over a total of 1938 genes of the T. neapolitana genome. Transcription of PFOR and LDH genes belonging to the CLF pathway was up-regulated by CO2 together with 6-phosphogluconolactonase (6PGL) and 6-phosphogluconate dehydratase (EDD) of the Entner–Doudoroff (ED) pathway. The transcriptomic study also revealed up-regulation of genes coding for the flavin-based enzymes NADH-dependent reduced ferredoxin:NADP oxidoreductase (NFN) and NAD-ferredoxin oxidoreductase (RNF) that control supply of reduced ferredoxin and NADH and allow energy conservation-based sodium translocation through the cell membrane. These results support the hypothesis that CO2 induces rearrangement of the central carbon metabolism together with activation of mechanisms that increase availability of the reducing equivalents that are necessary to sustain CLF. In this view, this study reports a first rationale of the molecular basis of CLF in T. neapolitana and provides a list of target genes for the biotechnological implementation of this process

Glucose-6-phosphate dehydrogenase plays a central role in the response of tomato (Solanum lycopersicum) plants to short and long-term drought

The present study was undertaken to investigate the expression, occurrence and activity of glucose 6 phosphate dehydrogenase (G6PDH e EC 1.1.1.49), the key-enzyme of the Oxidative Pentose Phosphate Pathway (OPPP), in tomato plants (Solanum lycopersicum cv. Red Setter) exposed to short- and long-term drought stress. For the first time, drought effects have been evaluated in plants under different growth conditions: in hydroponic laboratory system, and in greenhouse pots under controlled conditions; and in open field, in order to evaluate drought response in a representative agricultural environment. Interestingly, changes observed appear strictly associated to the induction of well known stress response mechanisms, such as the increase of proline synthesis, accumulation of chaperone Hsp70, and ascorbate peroxidase. Results show significant increase in total activity of G6PDH, and specifically in expression and occurrence of cytosolic isoform (cy-G6PDH) in plants grown in any cultivation system upon drought. Intriguingly, the results clearly suggest that abscissic acid (ABA) pathway and signaling cascade (protein phosphatase 2C e PP2C) could be strictly related to increased G6PDH expression, occurrence and activities. We hypothesized for G6PDH a specific role as one of the main reductants’ suppliers to counteract the effects of drought stress, in the light of converging evidences given by young and adult tomato plants under stress of different duration and intensity

Quality assurance for CMS Tracker LV and HV Power Supplies

This work describes the quality assurance measurements that have been carried out on about 2000 Power Supply Units produced in CAEN technology for the CMS Silicon Tracker Detector. The automate procedure and the characteristics of the dedicated Test Fixture developed for this activity are described in details. Magnetic field tolerance and radiation hardness of Tracker power supply units is also discussed at length

Giovan Battista Marino, Egloghe. Edizione critica

Questo lavoro propone un’edizione critica delle Egloghe di Giovan Battista Marino. Si tratta di un corpus di testi bucolici giovanili, composti durante gli ultimi anni trascorsi dal poeta a Napoli prima della fuga a Roma (1594-1600), che comprende quattro egloghe in endecasillabi sciolti (Tirsi, Dafne, Siringa, Pan), due egloghe in endecasillabi e settenari liberamente rimati (Il Lamento, Eco) e un poemetto pastorale in ottave (I Sospiri d’Ergasto). Il testo critico è fondato sull’esame di tutti i testimoni finora noti (un manoscritto e undici edizioni a stampa, di cui nove si sono rivelate descriptae) ed è accompagnato da un apparato articolato in due fasce distinte, la prima relativa agli errori e alle varianti sostanziali dei testimoni fondamentali, la seconda alle varianti formali (grafiche, fonetiche e morfologiche); nel caso dei Sospiri d’Ergasto, di cui disponiamo di una redazione successiva, più breve e molto rielaborata, inclusa dall'autore nella Sampogna (1620), una terza fascia d’apparato dà conto anche delle varianti evolutive attestate dalla seconda redazione. Testo e apparato sono corredati da una serie di note a piè di pagina di commento filologico in cui trovano puntuale giustificazione le scelte editoriali che si sono operate nella costituzione del testo. Apre il lavoro un’introduzione, che analizza nel dettaglio il contesto, le fonti e gli aspetti stilistici e contenutistici delle Egloghe, riconoscendo prestiti e debiti di situazione e di lessico rispetto sia alla poesia volgare (e in particolare alla poesia napoletana del Cinquecento, che ha i suoi maggiori esponenti in Sannazaro, Rota, Tansillo, Tasso) che a quella classica, e che si sofferma sulla questione, tutt’altro che pacifica, della datazione dei testi bucolici mariniani e dell’identificazione del loro possibile dedicatario, gettando nuova luce sulla prima stagione napoletana del poeta e sui suoi rapporti clientelari nella Napoli spagnola del Vicereame. All’introduzione segue un’ampia nota al testo, che cerca di ricostruire l’intricata trasmissione manoscritta e a stampa dell’opera proponendo, sulla base di un compiuto scrutinio testuale, un ordinamento stemmatico dell’intera tradizione.This dissertation provides a critical edition of the Egloghe of Giovan Battista Marino, a corpus of early bucolic texts composed during his last years in Naples before his flight to Rome (1594-1600). It includes four eclogues in blank hendecasyllables (Tirsi, Dafne, Siringa, Pan), two eclogues in freely rhymed hendecasyllables alternating with septenaries (Il Lamento, Eco) and a pastoral poem in octavas (I Sospiri d’Ergasto). The critical text was established by examining all the witnesses known to date (one manuscript and eleven printed editions, nine of which are deemed descriptae). It is accompanied by an apparatus divided into two distinct bands, the first relating to errors and substantial variants of the fundamental witnesses, the second to formal variants (graphic, phonetical and morphological variants). In the case of the poem I Sospiri d’Ergasto, a third band of apparatus accounts for the evolutionary variants attested by the later, shorter and much-reworked version of the poem included by the author in his Sampogna (1620). The text and apparatus are followed by a series of footnotes of philological commentary clarifying the editorial choices in the construction of the reading text. In the introduction, the context, the sources and the stylistic and content aspects of the Egloghe are analyzed in detail, retracing their literary background, both in vernacular poetry (in particular, the Neapolitan major 16th century poets, as Sannazaro, Rota, Tansillo, Tasso) as well as the classical tradition. The introduction also dwells on two debated questions: the dating of Marino’s bucolic texts and the identification of their possible dedicatee, shedding new light on the poet’s early Neapolitan season and his patronage relations in the Spanish viceroyalty of Naples. Following the introduction, an extensive philological note attempts to reconstruct the work’s intricate handwritten and printed transmission, proposing a stemmatic ordering of the entire tradition, based on an accomplished textual scrutinity

In children allergic to ragweed pollen, nasal inflammation is not influenced by monosensitization or polysensitization

BACKGROUND: In patients polysensitized to pollen allergens, the priming effect, by which the sensitivity of the nasal mucosa to an allergen is increased by the previous exposure to another allergen, is a known phenomenon. This study was aimed at evaluating the degree of nasal inflammation, assessed by nasal cytology, in children with allergic rhinitis (AR) from ragweed pollen according to being monosensitized or polysensitized. METHODS: The study included 47 children. Of them, 24 suffered from AR caused by sensitization to grass pollen and ragweed pollen (group A) and 23 were sensitized only to ragweed pollen (group B). In all patients, the severity of AR was assessed according to the Allergic Rhinitis and Its Impact on Asthma guidelines, and comorbidities were also evaluated. RESULTS: In group A, 16.7% of children had a mild intermittent AR, 4.2% a moderate-to-severe intermittent, 33.3% a mild persistent, and 45.8% a moderate-to-severe persistent; in group B, 26.1% of children had a mild intermittent AR, 0% a moderate-to-severe intermittent, 52.2% a mild persistent, and 21.7% a moderate-to-severe persistent. No significant difference was detected in the number of the considered comorbidities between the two groups. The cell counts of neutrophils, eosinophils, lymphocytes/plasma cells, and mast cells were high but not significantly different in the two groups. CONCLUSION: These findings show that the degree of nasal inflammation found in children with ragweed-induced AR is not influenced by additional allergy to grass pollen and confirm the previously reported absence of priming effect in ragweed allergy

Protecting crop species from biotic and abiotic constraints in the era of global change: Are we ready for this challenge?

Reliable andaffordable supply of food is of crucial importance to the progress andstability of human societies. During the last century, we have assisted to anextraordinary increase of crop yields, especially for the most widespread andconsumed crop species, such as rice, wheat, corn and soybean. The Broadbalkexperiment, one of the oldest continuous agronomic experiments in the world,have showed how half of the increase of crop productivity is mainly due to the improvementsintroduced through plant breeding and half through to agronomical practices,although both are dependent on each other (Rasmussen et al., 1998). The development of a huge numbers of scientificplant breeding programs has been of vital relevance in improving crop varietiesand productivity. In addition, collection and spread of improved germplasmaround the world have ensured that all breeders could quickly benefit from theadvances obtained by others. On the other side, based on Lawes and Gilbert'swork in the previous century, the main advances in agronomy consisted on thecontinued use of fertilizers, the true value of which could only be realized inthe presence of suitable varieties and in the absence (or under controlledpressure) of competition from weeds, pest and diseases. Therefore, cropprotection became crucial and it was achieved by the improvements of theagrochemical industry, which has developed sophisticated, high-targeting andmore efficient agrochemicals. Taken together, the use of new high-yieldvarieties in association with chemical fertilizers and agrochemicals,controlled water-supply (irrigation), and new methods of cultivation, includingmechanization, are commonly identified under the term “Green Revolution” which wasconied between ’30 and ’60 and was responsible in some cases for doubling (oreven triplicating) the agricultural production for many crops species, inparticular cereals. The incremented crop productivity hasbrought many social gains, such as reducing the malnutrition, lowering foodprice, increasing food security. Moreover, since the economic sustainability isthe most important factor for the adoption of a crop for farmers (Sgroi et al., 2014; Testa et al., 2015), the increased crop productivity occurred in the lastdecades, has determined a positive impact on the development of several ruralareas. The increase of cropyield, has caused, on the other side, large changes in rural societies due tothe migration of population from the countryside (caused by the decrease ofmanpower needs) to towns and cities where the industrialization offered moreopportunities. The better living conditions lead to the highest increment ofword population that has ever been documented: from 2.5 b people to 5.2 b in 40years (1950-1990; UNR, 2004). Nowadays, word population is predicted toincrease from 7.4 b people (May, 2016), to 8.4 b in 2030 and 9.5 b in 2050 (U.SCensus Bureau). In addition, people rise out of poverty, higher livingstandards, such as greater meat consumption, and personal mobility will increaseeven more the demand on food production (and quality), animal feed, fiber, andfuels. Thus feeding, clothing and fueling a more densely populated planet isprobably the key challenge of our century. Industrializationand anthropic activities have also imposed profound alterations to theenvironment and, decade after decade, have contributed to alter dramaticallythe life conditions on Earth leading to the so called “Global Change” (alsoreferred as “Global Warming” or “Climate Change”), phenomenon from which we areactually trying to run for cover. Based on several reports produced by theIntergovernmental Panel on Climate Change, it emerges as the most hazardouseffects of Global Change, such as rising temperatures and heat waves, prolongedperiods of drought, and incremented levels of pollutants in all the compartmentsof biosphere can cause more frequent and severe fluctuations in cropproductivity, but also can seriously threaten the availability of arable land;for example increasing the amplitude of soil/water salinization or soilerosion. The total surface of arable soil is also undermined by the constantrequirement of lands for human activities that, beyond the direct effect ofoverbuilding, in many cases also increase the pollution of surrounding areas, forexample through the release of heavy metals, hydrocarbons, xenobiotics or otherpollutants in soil, water, and/or in the atmosphere. Global Change alsoinfluences the ecology of weeds, pests and disease, with possible implicationsfor crop protection and pesticide use. The ability of science to makepredictions on the impact of Global Change on ecosystem interactions is limitedbecause models that include multiple interactive effects of Global Change arestill relatively rare and the comprehension of results obtained from modelsystems results quite complicated. For this reason, despite the scientificcommunity concords on the dramatic impact of Global Change on cropproductivity, predictions may have sometimes-different facets depending on theinformation source. Some researchers reported however that in the time span1981-2001, changes in precipitation and increased temperatures have already inducedannual losses of wheat, maize and barley production of about 40 million tons peryear (Lobell and Field, 2007). Thus, beyond future prediction(s) of GlobalChange effect, humanity is still experiencing the effects this phenomenon forat least three decades. It is evident that in a near future akey challenge for humanity is to increase the productivity of crop specieswhile decreasing water supply, the use of fossil fuels, chemical fertilizer,pesticides (and more in general agrochemicals), and other negativeenvironmental inputs. On the other side, less clear is how agriculture’s outputcan increase so substantially without significantly increasing itsenvironmental footprint. Plant physiologyand biochemistry have developed as powerful disciplines during the 20thcentury, but only in a few cases they have led to relevant crop improvement,and in any case, nothing as compared to the amazing gains on crop productivityobtained through the classical genetic breeding from 1930 to 1960. This islikely because the links between the biochemistry and genetics of the processesdescribed were not established, but rather high-yield genotypes were selectedonly for this desired feature lacking to explore the reason on the bases ofthis gain. The situation has changed after the discovery of the DNA structureby Watson and Crick (1953) and even more after ’70, when the first positiveresults with transgenic plants were obtained. From that time onward, theability to control one or few genes has also deepened the knowledge on the biochemicalmechanisms underlying the genetic process that has been modified. This newapproach, associated with the rapid development of “omic” sciences, has thepotentiality to lead to significant advances either in crop yield, quality,and/or plant protection in a near future. The future need for higher cropproductivity must parallel with a reduction of agronomical inputs as in thepast high-yield genotypes have been selected for their performances with highinputs, especially fertilizers and pesticides. Agricultural emissions from cropand livestock production grew from 4.7 billion tons of carbon dioxideequivalents (CO2 eq) in 2001 to over 5.3 billion tons in 2011. Inthe same period, annual emissions from fertilizers increased by 37% and in 2011the world total annual emissions fromsynthetic fertilizers averaged 725 Mt CO2 eq, about 14% of total emissionsfrom agriculture in the same year (Tubiello etal., 2014). Advances in the basic knowledge of plant genetic, physiologyand biochemistry should thereby be address to increase the efficiency of inpututilization by plants in order to reduce the input level. Technologicaladvances on instrumentations, such as precision farming tools (such as GPStracking devices designed for farming), as well as agronomical practices (i.e.advanced organic farming, eco-friendly soil amendments) can also significant contributeto achieve this goal. The extensiveemploy of synthetic pesticides against pests of agricultural and veterinaryimportance, especially in developing countries, lead to important concerns forhuman health and the environment (Desneux etal., 2007; Hemingway and Ranson, 2000; Naqqash et al., 2016). In this scenario, the need for effective and eco-friendlycontrol tools has gained increasing attention in latest years (Benelli, 2015;2016). Besides this, a further challenge for crop and livestock protectionnowadays, is the improvement of the success of biological control programs,developing effective quarantine procedures and proper evaluation of thenon-target effects of biocontrol agents (Hajek et al., 2016). Furthermore, chemoecological knowledgeabout pests and biocontrol agents may represent a valid help to improve integratedpest management strategies. Indeed, foraging kairomones exploited bycarnivorous arthropods have been successfully tested as field lures to attractcarnivores in damaged agricultural habitats. However, practical applications offoraging kairomones seem to be restricted by major concerns including carnivorousarthropod habituation, carnivorous arthropod time-wasting on victim-free crops,exploitation of host-borne cues by hyperparasitoids and lack of foraging kairomones specificity due totri-trophic interactions sharing a given habitat that use identical chemicalsignals, thus confounding species-specific biological control agents (Kaplan,2012). Further research on new applications of physical and chemical signalsexploited by carnivorous arthropods is urgently required. Physical andolfactory cues can be used to experience mass-reared predators and parasitoids,via sensitization or associative learning practices (Giunti et al., 2016). This could help toovercome critical steps in mass rearing of biocontrol organisms and improvebeneficial performances of carnivorous arthropods in the field. In view of the growing scientificinterest on the effects of Global Changes factors on the relationship betweenplant-pest-environment, in this issue a collection of papers focused on thistopic are presented. Beyond awareness of the deleterious impact of GlobalChange, factor which should lead humanity to a wiser use Earth’s resources, we believethat only the in-depth comprehension of mechanisms adopted by crop species toendurance under stress (Landi et al.,2012; 2013; 2014; 2015; Pardossi et al.,2015; Penella et al., 2016; Tattini et al.,2014) associated with new eco-friendly methods to control crop pests anddiseases may represent a way to contrast the effect of Global Change meanwhilewe are attempting to increase crop productivity for supporting the needs of anincreasingly crowded planet

Discovery of magnetic fields in central stars of planetary nebulae

For the first time we have directly detected magnetic fields in central stars of planetary nebulae by means of spectro-polarimetry with FORS1 at the VLT. In all four objects of our sample we found kilogauss magnetic fields, in NGC1360 and LSS1362 with very high significance, while in EGB5 and Abell36 the existence of a magnetic field is probable but with less certainty. This discovery supports the hypothesis that the non-spherical symmetry of most planetary nebulae is caused by magnetic fields in AGB stars. Our high discovery rate demands mechanisms to prevent full conservation of magnetic flux during the transition to white dwarfs.Comment: 8 pages, 4 figures, Accepted for Publication by Astronomy & Astrophysics See also press release by A&A on their homepage www.edpsiences.or