108 research outputs found

    Full Orbit Sequences in Affine Spaces via Fractional Jumps and Pseudorandom Number Generation

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    Let nn be a positive integer. In this paper we provide a general theory to produce full orbit sequences in the affine nn-dimensional space over a finite field. For n=1n=1 our construction covers the case of the Inversive Congruential Generators (ICG). In addition, for n>1n>1 we show that the sequences produced using our construction are easier to compute than ICG sequences. Furthermore, we prove that they have the same discrepancy bounds as the ones constructed using the ICG.Comment: To appear in Mathematics of Computatio

    Relaxation of axially confined 400 GeV/c protons to planar channeling in a bent crystal

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    An investigation on the mechanism of relaxation of axially confined 400 GeV/c protons to planar channeling in a bent crystal was carried out at the extracted line H8 from CERN Super Proton Synchrotron. The experimental results were critically compared to computer simulations, showing a good agreement. We identified a necessary condition for the exploitation of axial confinement or its relaxation for particle beam manipulation in high-energy accelerators. We introduce the idea of using a short bent crystal, aligned with one of its main axis to the beam direction, as a beam steerer or a beam splitter with adjustable intensity in the field of particle accelerators. In particular, in the latter case, a complete relaxation from axial confinement to planar channeling takes place, resulting in beam splitting into the two strongest skew planar channels.An investigation on the mechanism of relaxation of axially confined 400 GeV/c protons to planar channeling in a bent crystal was carried out at the extracted line H8 from CERN Super Proton Synchrotron. The experimental results were critically compared to computer simulations, showing a good agreement. We identified a necessary condition for the exploitation of axial confinement or its relaxation for particle beam manipulation in high-energy accelerators. We introduce the idea of using a short bent crystal, aligned with one of its main axis to the beam direction, as a beam steerer or a beam splitter with adjustable intensity in the field of particle accelerators. In particular, in the latter case, a complete relaxation from axial confinement to planar channeling takes place, resulting in beam splitting into the two strongest skew planar channels

    Serum levels of Ochratoxin A in dogs with chronic kidney disease (CKD): a retrospective study

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    Ochratoxin A (OTA) is a mycotoxin produced by secondary metabolism of several fungi belonging to the genera Aspergillus and Penicillium. OTA is potentially nephrotoxic, neurotoxic, immunotoxic and carcinogenic in several animal species and in humans. This toxin has been detected in several human food and animal feed. The aim of this study was to determine OTA in blood samples of healthy and affected by chronic kidney disease (CKD) dogs. CKD group showed higher incidence of OTA-positivity than healthy dogs (96% vs. 56%) and a significantly higher median value of OTA plasma concentration (0.008 ng/ml vs. 0.144 ng/ml). No significant correlation was observed between OTA levels and creatinine values in CKD dogs. This is first study regarding OTA detection in plasma samples of healthy and CKD dogs; the presence of this toxin is higher in nephropatic patients but is not yet clear, if it is correlated with progression of the disease

    Living in a Mediterranean city in 2050: broadleaf or evergreen ‘citizens’?

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    The predicted effects of global change (GC) will be exacerbated in the more densely populated cities of the future, especially in the Mediterranean basin where some environmental cues, such as drought and tropospheric ozone (O3) pollution, already mine seriously plant survival. Physiological and biochemical responses of a Mediterranean, evergreen, isohydric plant species (Quercus ilex) were compared to those of a sympatric, deciduous, anisohydric species (Q. pubescens) under severe drought (20% of the effective daily evapotranspiration) and/or chronic O3 exposure (80 ppb for 5 h dayâ1 for 28 consecutive days) to test which one was more successful in those highly limiting conditions. Results show that (i) the lower reduction of total leaf biomass of Q. ilex as compared to Q. pubescens when subjected to drought and drought à O3 (on average â59 vs â70%, respectively); (ii) the steeper decline of photosynthesis found in Q. pubescens under drought (â87 vs â81%) and drought à O3 (â69 vs â59%, respectively); (iii) the increments of malondialdehyde (MDA) by-products found only in drought-stressed Q. pubescens; (iv) the impact of O3, found only in Q. pubescens leaves and MDA, can be considered the best probes of the superiority of Q. ilex to counteract the effect of mild-severe drought and O3 stress. Also, an antagonistic effect was found when drought and O3 were applied simultaneously, as usually happens during typical Mediterranean summers. Our dataset suggests that on future, the urban greening should be wisely pondered on the ability of trees to cope the most impacting factors of GC, and in particular their simultaneity

    Variations in physiological and biochemical traits of oak seedlings grown under drought and ozone stress

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    Despite the huge biodiversity characterizing the Mediterranean environment, environmental constraints, such as high sunlight and high temperatures alongside with dry periods, makes plant survival hard. In addition, high irradiance leads to increasing ozone (O3 ) concentrations in ambient air. In this era of global warming, it is necessary to understand the mechanisms that allow native species to tolerate these environmental constraints and how such mechanisms interact. Three Mediterranean oak species (Quercus ilex, Q. pubescens and Q. cerris) with different features (drought tolerant, evergreen or deciduous species) were selected to assess their biometrical, physiological and biochemical responses under drought and/or O3 stress (80-100 nl l(-1) of O3 for 5 h d(-1) for 77 consecutive days). Leaf visible injury appeared only under drought stress (alone or combined with O3 ) in all three species. Drought × O3 induced strong reductions in leaf dry weight in Q. pubescens and Q. cerris (-70 and -75%, respectively). Alterations in physiological (i.e. decrease in maximum carboxylation rate) and biochemical parameters (i.e. increase in proline content and build-up of malondialdehyde by-products) occurred in all the three species, although drought represented the major determinant. Q. ilex and Q. pubescens, which co-occur in dry environments, were more tolerant to drought and drought × O3 . Quercus ilex was the species in which oxidative stress occurred only when drought was applied with O3 . High plasticity at a biochemical level (i.e. proline content) and evergreen habitus are likely on the basis of the higher tolerance of Q. ilex

    Synchronous anal canal cancer and cervical cancer: report of a case and management implication

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    Background: This is the case report of a synchronous anal canal cancer and cervical cancer in a patient who underwent definitive chemoradiotherapy (CRT) and radical surgery for anal canal and cervical carcinoma, respectively. Case Report: A 55-year-old woman was diagnosed with cT4a cN1 Mx anal canal squamous cell carcinoma and stage IA2 cervical squamous cell carcinoma, based on biopsy and imaging. Definitive CRT consisted of radiotherapy (total dose of 59.4 Gy) and concomitant mitomycin (10 mg/m(2)) and 5-fluorouracil (750 mg/m(2)/5 daily continuous infusion) during the first and last week of radiation. The patient exhibited a complete clinical and radiological response. A radical hysterectomy with pelvic lymphadenectomy was then performed. At the last follow-up (30 months), the patient is still disease-free without any treatment-associated complications. Conclusion: There is limited information in the literature regarding treatment strategy and outcome of patients with synchronous anal canal and cervical cancer. A two-step treatment, including CRT and radical hysterectomy, is likely to be accepted as valid option

    Cross‐Talk between Physiological and Metabolic Adjustments Adopted by Quercus cerris to Mitigate the Effects of Severe Drought and Realistic Future Ozone Concentrations

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    Global climate change represents a moving target for plant acclimation and/or adaptation, especially in the Mediterranean basin. In this study, the interactions of severe drought (20% of the effective daily evapotranspiration) and O3 fumigation (80 ppb, 5 h day−1, for 28 consecutive days) on (i) photosynthetic performance, (ii) cell membrane stability, (iii) hydric relations, (iv) accumulation of compatible solutes, and (v) lipophilic antioxidant compounds were investigated in young Quercus cerris plants. In addition to the typical drought-induced stomatal closure, imposition of water withholding dramatically influenced the profile of stress-associated metabolites, i.e., abscisic acid (ABA), proline, and lipophilic antioxidants. However, plants were not able to delay or prevent the negative effects of water deficit, the greatest impacting factor in this study. This translated into a steep decline of photosynthetic efficiency, leaf hydration, and membrane fluidity and permeability. When water stress was coupled with O3, plants orchestrated cross-talk among ABA, proline, and sugar in fully-expanded mature leaves, partially leading to a premature senescenc

    Losing the warning signal: Drought compromises the cross-talk of signaling molecules in quercus ilex exposed to ozone

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    Understanding the interactions between drought and acute ozone (O3) stress in terms of signaling molecules and cell death would improve the predictions of plant responses to climate change. The aim was to investigate whether drought stress influences the responses of plants to acute episodes of O3 exposure. In this study, the behavior of 84 Mediterranean evergreen Quercus ilex plants was evaluated in terms of crosstalk responses among signaling molecules. Half of the sample was subjected to drought (20% of the effective daily evapotranspiration, for 15 days) and was later exposed to an acute O3 exposure (200 nL L-1 for 5 h). First, our results indicate that in well-water conditions, O3 induced a signaling pathway specific to O3-sensitive behavior. Second, different trends and consequently different roles of phytohormones and signaling molecules (ethylene, ET; abscisic acid, ABA; salycilic acid, SA and jasmonic acid, JA) were observed in relation to water stress and O3. A spatial and functional correlation between these signaling molecules was observed in modulating O3-induced responses in well-watered plants. In contrast, in drought-stressed plants, these compounds were not involved either in O3-induced signaling mechanisms or in leaf senescence (a response observed in water-stressed plants before the O3-exposure). Third, these differences were ascribable to the fact that in drought conditions, most defense processes induced by O3 were compromised and/or altered. Our results highlight how Q. ilex plants suffering from water deprivation respond differently to an acute O3 episode compared to well-watered plants, and suggest new effect to be considered in plant responses to environmental changes. This poses the serious question as to whether or not multiple high-magnitude O3 events (as predicted) can change these cross-talk responses, thus opening it up possible further investigations

    Fonti per la storia degli archivi degli antichi Stati italiani (Rome: Ministero dei beni e delle attività culturali e del turismo, 2016), vol. 49 of the ‘Fonti’ (Sources) series of the Pubblicazioni degli Archivi di Stato, edited with Andrea Guidi and Alessandro Silvestri

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    A collection of 330 documents on the history of Italian archives, 1200-1800. The collection is prefaced by a general introduction and the documents are divided into six thematic chapters: the politics of archives; the organisation and arrangement of archives; the material culture of archives; the social history of archivists; the uses of archives; and pre-modern scholarly research in archives. Each chapter is prefaced by an introduction and each document is edited, introduced and annotated with extensive references. The case studies include: the Republic of Venice, the Duchy of Milan, the Duchy of Ferrara-Modena, the Republic of Florence and the Duchy of Tuscany, the papacy, the Kingdom of Naples, the Kingdom of Sicily

    How Quercus ilex L. saplings face combined salt and ozone stress: a transcriptome analysis

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    Background: Similar to other urban trees, holm oaks (Quercus ilex L.) provide a physiological, ecological and social service in the urban environment, since they remove atmospheric pollution. However, the urban environment has several abiotic factors that negatively influence plant life, which are further exacerbated due to climate change, especially in the Mediterranean area. Among these abiotic factors, increased uptake of Na + and Cl − usually occurs in trees in the urban ecosystem; moreover, an excess of the tropospheric ozone concentration in Mediterranean cities further affects plant growth and survival. Here, we produced and annotated a de novo leaf transcriptome of Q. ilex as well as transcripts over- or under-expressed after a single episode of O3 (80 nl l-1, 5 h), a salt treatment (150mM for 15 days) or a combination of these treatments, mimicking a situation that plants commonly face, especially in urban environments. Results: Salinity dramatically changed the profile of expressed transcripts, while the short O3 pulse had less effect on the transcript profile. However, the short O3 pulse had a very strong effect in inducing over- or under-expression of some genes in plants coping with soil salinity. Many differentially regulated genes were related to stress sensing and signalling, cell wall remodelling, ROS sensing and scavenging, photosynthesis and to sugar and lipid metabolism. Most differentially expressed transcripts revealed here are in accordance with a previous report on Q. ilex at the physiological and biochemical levels, even though the expression profiles were overall more striking than those found at the biochemical and physiological levels. Conclusions: We produced for the first time a reference transcriptome for Q. ilex, and performed gene expression analysis for this species when subjected to salt, ozone and a combination of the two. The comparison of gene expression between the combined salt + ozone treatment and salt or ozone alone showed that even though many differentially expressed genes overlap all treatments, combined stress triggered a unique response in terms of gene expression modification. The obtained results represent a useful tool for studies aiming to investigate the effects of environmental stresses in urban-adapted tree species
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