1,337 research outputs found

    Ecosystem services and biodiversiy for agricultural landscape sustainability

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    The aim of this research was to provide a contribution to the study of agricultural landscape sustainability through ecological intensification concept. Ecological intensification advocates to maintain or enhance agricultural production through the promotion of biodiversity and associated ecosystem services. Therefore, we analyzed the sustainability of agricultural landscapes by assessing the impacts of agricultural intensification on (i) biodiversity and (ii) ecosystem services. In particular, after an introduction to the main topic of research (Chapter 1), the thesis is divided into four research papers: the first paper (Chapter 2) focuses on the functional quality of agricultural landscapes as defined by biodiversity and sensitivity to disturbance. Relationships between the structural characteristics and the functional qualities of agricultural landscapes have been explored and insights for their ecological and sustainable management have been obtained. We found landscape functional quality to increase with high percentage of fairly large and not too isolated semi-natural areas and a high level of landscape heterogeneity. In addition, our analysis underlined the importance of specific semi-natural habitat types such as meadows and woods, rather than others (e.g. hedgerows) for improving functional quality of agricultural landscapes. The second paper (Chapter 3) examines how agricultural intensification may affect the spread of exotic plant species (i.e. archaeophytes and neophytes) in different semi-natural habitats. We found differences among habitats on their susceptibility to be invaded by exotic plants changed according to the proximity to the source or amount of disturbance in the landscape. The presence of exotic plant species (both neophytes and archaeophytes) leads to a greater homogenization of the flora in different semi-natural habitats across the landscape. The third paper (Chapter 4) focuses on the effects of conservation tillage, in contrast to conventional tillage, on the supply of multiple ecosystems services supporting cereal production. The ecosystem services considered in the experiment were (i) production, (ii) weed control, (iii) natural aphid pest control and (iv) soil quality (SOM quantity). In addition, we examined whether landscape complexity affects the supply of natural pest control and weed control and whether intensity of fertilization influences production service and weed control. The results showed that tillage system, landscape complexity and fertilization had different influences on ecosystem services. Production did not differ between conservation and conventional tillage, whereas fertilization increased production. Conservation tillage decreased weed control services and favored a greater diversity of weeds. Landscape complexity and fertilization did not show any influence neither on weed control services nor on weed diversity. We found a greater effect of natural pest control by ground predators under conservation tillage. On the other hand, parasitism on aphids was not affected by tillage system, but increased with landscape complexity. Finally conservation tillage positively affected the soil quality. The fourth paper (Chapter 5) focuses on a single ecosystem service: natural aphid pest control. The paper deals with the interactions of soil management (i.e. conservation tillage), landscape complexity and natural enemy communities with the biological control service provided by different guilds of natural enemies in winter cereal crops (birds, flying insects/vegetation-dwelling predators and ground-dwelling predators). We found that conservation tillage supports greater overall BC of aphids in winter cereals than conventional tillage. Primarily this was due to ground-dwelling predators (carabids and arachnoids), whereas some of the other natural enemy guilds studied contributed little to aphid population control. Landscape complexity had a positive effect on parasitism only under conventional tillage but not under conservation tillage, mainly thanks to vegetation-dwelling predators and BC was higher in complex than in simple landscapes. The general conclusion of the research underlines that agricultural landscape management finalized to the improvement of ecological intensification is possible, ensuring production and environmental sustainability. The research highlights the need to join the application of environmentally sustainable cultivation practices combined with a thoughtful landscape planning mindful of semi-natural habitat type and their configuration in the pattern

    Quantum median filter for total variation image denoising

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    In this new computing paradigm, named quantum computing, researchers from all over the world are taking their first steps in designing quantum circuits for image process- ing, through a difficult process of knowledge transfer. This effort is named quantum image processing, an emerging research field pushed by powerful parallel comput- ing capabilities of quantum computers. This work goes in this direction and proposes the challenging development of a powerful method of image denoising, such as the total variation (TV) model, in a quantum environment. The proposed quantum TV is described and its sub-components are analysed. Despite the natural limitations of the current capabilities of quantum devices, the experimental results show a competitive denoising performance compared to the classical variational TV counterpar

    Conservation tillage mitigates the negative effect of landscape simplification on biological control

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    Biological pest control is a key ecosystem service, and it depends on multiple factors acting from the local to the landscape scale. However, the effects of soil management on biological control and its potential interaction with landscape are still poorly understood. In a field exclusion experiment, we explored the relative effect of tillage system (conservation vs. conventional tillage) on aphid biological control in 15 pairs of winter cereal fields (barley and wheat) selected along a gradient of landscape complexity. We sampled the abundance of the main natural enemy guilds, and we evaluated their relative contribution to aphid predation and parasitism. Conservation tillage was found to support more abundant predator communities and higher aphid predation (16% higher than in the fields managed under conventional tillage). In particular, both the abundance and the aphid predation of vegetation- and ground-dwelling arthropods were increased under conservation tillage conditions. Conservation tillage also increased the parasitism rate of aphids. A high proportion of semi-natural habitats in the landscape enhanced both aphid parasitism and predation by vegetation-dwelling organisms but only in the fields managed under conventional tillage. The better local habitat quality provided by conservation tillage may compensate for a low-quality landscape. Synthesis and applications. Our study stresses the importance of considering both soil management and landscape composition when planning strategies to maximize biological control services in agro-ecosystems, highlighting the role played by conservation tillage in supporting natural enemy communities. In simple landscapes, the adoption of conservation tillage will locally improve biological control provided by both predators and parasitoids mitigating the negative effects of landscape simplification. Moreover, considering the small scale at which both predation and parasitism responded to landscape composition, a successful strategy to improve biological control would be to establish a fine mosaic of crop and non-crop areas such as hedgerows, tree lines and small semi-natural habitat patches. \ua9 2016 British Ecological Society

    One-Pot Synthesis of Biheterocycles Based on Indole and Azole Scaffolds Using Tryptamines and 1,2-Diaza-1,3-dienes as Building Blocks

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    partially_open7noThe rapid and expedient assembly of three new classes of biheterocycles of biological interest, viz. indole–imidazoles 4, indole–pyrroles 6 and indole–triazoles 8 was accomplished using different combinations of tryptamines, 1,2-diaza-1,3-dienes, aldehydes, and/or alkynes as readily available building blocks. Twenty-six derivatives were thus prepared in excellent yields (up to 100 %). The products were screened for in-vitro biological studies. Some of these revealed promising anticancer activity against MCF7 and Caco-2 human tumor cell lines.mixedMantenuto, Serena; Lucarini, Simone; De Santi, Mauro; Piersanti, Giovanni; Brandi, Giorgio; Favi, Gianfranco; Mantellini, FabioMantenuto, Serena; Lucarini, Simone; DE SANTI, Mauro; Piersanti, Giovanni; Brandi, Giorgio; Favi, Gianfranco; Mantellini, Fabi

    TRPA1 mediates aromatase inhibitor-evoked pain by the aromatase substrate androstenedione

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    Aromatase inhibitors (AI) induce painful musculoskeletal symptoms (AIMSS), which are dependent upon the pain transducing receptor TRPA1. However, as the AI concentrations required to engage TRPA1 in mice are higher than those found in the plasma of patients, we hypothesized that additional factors may cooperate to induce AIMSS. Here we report that the aromatase substrate androstenedione, unique among several steroid hormones, targeted TRPA1 in peptidergic primary sensory neurons in rodent and human cells expressing the native or recombinant channel. Androstenedione dramatically lowered the concentration of letrozole required to engage TRPA1. Notably, addition of a minimal dose of androstenedione to physiologically ineffective doses of letrozole and oxidative stress byproducts produces AIMSS-like behaviors and neurogenic inflammatory responses in mice. Elevated androstenedione levels cooperated with low letrozole concentrations and inflammatory mediators were sufficient to provoke AIMSS-like behaviors. The generation of such painful conditions by small quantities of simultaneously administered TRPA1 agonists justifies previous failure to identify a precise link between AIs and AIMSS, underscoring the potential of channel antagonists to treat AIMSS

    Safety issues in nutraceutical exploitation of Chlorella vulgaris, Arthrospira Platensis and Scenedesmus sp. microalgae

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    Microalgae contain many bioactive compounds, which may be exploited in food and nutraceutical fields. Bisphenol A (BPA) is a contaminant in microalgae that may be released from polymeric plastics. Since it is responsible for toxic effects on humans, the European legislation set the legal BPA limit within foods at 50 µg kg−1 of food weight. In this work, a fast ultrasounds solid-liquid extraction of BPA from commercial microalgal powders of Chlorella vulgaris, Arthrospira Platensis and Scenedesmus sp. was optimized. To increase selectivity, BPA was derivatized by using N,O-bis(trimethylsilyl)trifluoroacetamide/trimethylchlorosilane (BSTFA-TMCS) and it was analysed by GC-MS in selected ion monitoring mode. A design of experiment (DOE) optimization study of the reaction conditions was performed. The analytical method was validated by determining selectivity, linearity (R2= 0.99999 ± 3.3165E-07), precision, accuracy (99.92 ± 9.83E-02 %), recovery (99.65 ± 3.61E-02 %) and sensitivity (LoD= 0.547 ± 9.94E-02 µg kg−1; LoQ= 1.823 ± 3.31E-1 µg kg−1). The overall method proved to be fast, with high recovery and suitable to selectively and sensitively determine the content of BPA, eliminating the interferences from extraction and allowing to control the safety profile of microalgae. Dried microalgae cultivated in a polycarbonate reactor, were found to contain an amount of BPA 6 times exceeding the legal limit

    TRPA1/NOX in the soma of trigeminal ganglion neurons mediates migraine-related pain of glyceryl trinitrate in mice

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    Glyceryl trinitrate is administered as a provocative test for migraine pain. Glyceryl trinitrate causes prolonged mechanical allodynia in rodents, which temporally correlates with delayed glyceryl trinitrate-evoked migraine attacks in patients. However, the underlying mechanism of the allodynia evoked by glyceryl trinitrate is unknown. The proalgesic transient receptor potential ankyrin 1 (TRPA1) channel, expressed by trigeminal nociceptors, is sensitive to oxidative stress and is targeted by nitric oxide or its by-products. Herein, we explored the role of TRPA1 in glyceryl trinitrate-evoked allodynia. Systemic administration of glyceryl trinitrate elicited in the mouse periorbital area an early and transient vasodilatation and a delayed and prolonged mechanical allodynia. The systemic, intrathecal or local administration of selective enzyme inhibitors revealed that nitric oxide, liberated from the parent drug by aldehyde dehydrogenase 2 (ALDH2), initiates but does not maintain allodynia. The central and the final phases of allodynia were respectively associated with generation of reactive oxygen and carbonyl species within the trigeminal ganglion. Allodynia was absent in TRPA1-deficient mice and was reversed by TRPA1 antagonists. Knockdown of neuronal TRPA1 by intrathecally administered antisense oligonucleotide and selective deletion of TRPA1 from sensory neurons in Advillin-Cre; Trpa1fl/fl mice revealed that nitric oxide-dependent oxidative and carbonylic stress generation is due to TRPA1 stimulation, and resultant NADPH oxidase 1 (NOX1) and NOX2 activation in the soma of trigeminal ganglion neurons. Early periorbital vasodilatation evoked by glyceryl trinitrate was attenuated by ALDH2 inhibition but was unaffected by TRPA1 blockade. Antagonists of the calcitonin gene-related peptide receptor did not affect the vasodilatation but partially inhibited allodynia. Thus, although both periorbital allodynia and vasodilatation evoked by glyceryl trinitrate are initiated by nitric oxide, they are temporally and mechanistically distinct. While vasodilatation is due to a direct nitric oxide action in the vascular smooth muscle, allodynia is a neuronal phenomenon mediated by TRPA1 activation and ensuing oxidative stress. The autocrine pathway, sustained by TRPA1 and NOX1/2 within neuronal cell bodies of trigeminal ganglia, may sensitize meningeal nociceptors and second order trigeminal neurons to elicit periorbital allodynia, and could be of relevance for migraine-like headaches evoked by glyceryl trinitrate in humans

    Nurses and Night Shifts. Poor Sleep Quality Exacerbates Psychomotor Performance

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    In Europe, 40% of health-care employees are involved in shift work. The altered sleep/wake rhythm of night-shift nurses is also associated with deteriorated cognitive efficiency. In this study, we examine the effects of the night shift on psychomotor performance, sleepiness, and tiredness in a large sample of shift-working nurses and evaluated if poor sleep quality, sex, age, or years on the job could impact on a better adaptation to shift work. Eighty-six nurses with 8-h-rapidly-rotating-shifts were evaluated at the end of three shifts (morning/afternoon/night) for sleepiness and tiredness. Sleepiness, as measured by the Karolinska Sleepiness Scale, and tiredness, as measured by the Tiredness Symptoms Scale, were more pronounced after the night shift. These increases were paralleled by lower attentional performance on the psychomotor vigilance task (PVT) after the night shift. While sex, age, and years on the job did not affect PVT performance after the night shift, lower sleep quality (Pittsburgh Sleep Quality, PSQI > 5) was associated with decreased performance. The high prevalence of altered sleep quality showed that nurses, and shift workers in general, are at risk for a poor sleep quality. The evaluation of sleep quality through PSQI could represent a rapid, inexpensive tool to assess health-care workers assigned to rotating night shifts or to evaluate nurses who coped poorly with night-shift work

    Una mirada crítica sobre Lengua Madre Una conversación con María Teresa Andruetto (23 de diciembre de 2013)

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    Una mirada crítica sobre Lengua MadreUna conversación con María Teresa Andruetto(23 de diciembre de 2013)por Costanza Borghi, Serena Cappellini, Sara De Simone,Alma Martini, Valentina Paleari, Marco Pozzoni,Annamaria Rodio, Beatrice Tresold
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