1,108 research outputs found

    Combining the conservation of biodiversity with the provision of ecosystem services in urban green infrastructure planning. Critical features arising from a case study in the metropolitan area of Rome

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    A large number of green infrastructure (GI) projects have recently been proposed, planned and implemented in European cities following the adoption of the GI strategy by the EU Commission in 2013. Although this policy tool is closely related to biodiversity conservation targets, some doubts have arisen as regards the ability of current urban GI to provide beneficial effects not only for human societies but also for the ecological systems that host them. The aim of this work is to review the features that should be considered critical when searching for solutions that simultaneously support biodiversity and guarantee the provision of ecosystem services (ES) in urban areas. Starting from a case study in the metropolitan area of Rome, we highlight the role of urban trees and forests as proxies for overall biodiversity and as main ecosystem service providers. We look beyond the individual functional features of plant species and vegetation communities to promote the biogeographic representativity, ecological coherence and landscape connectivity of new or restored GI elements

    Enhancement of Anaerobic Digestion with Nanomaterials : A Mini Review

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    Altres ajuts: Fundación Ramón Areces: projecte META2NOL/CIVP19A5952In recent years, the number of articles reporting the addition of nanomaterials to enhance the process of anaerobic digestion has exponentially increased. The benefits of this addition can be observed from different aspects: an increase in biogas production, enrichment of methane in biogas, elimination of foaming problems, a more stable and robust operation, absence of inhibition problems, etc. In the literature, one of the current focuses of research on this topic is the mechanism responsible for this enhancement. In this sense, several hypotheses have been formulated, with the effect on the redox potential caused by nanoparticles probably being the most accepted, although supplementation with trace materials coming from nanomaterials and the changes in microbial populations have been also highlighted. The types of nanomaterials tested for the improvement of anaerobic digestion is today very diverse, although metallic and, especially, iron-based nanoparticles, are the most frequently used. In this paper, the abovementioned aspects are systematically reviewed. Another challenge that is treated is the lack of works reported in the continuous mode of operation, which hampers the commercial use of nanoparticles in full-scale anaerobic digesters

    Adsorptive removal of siloxanes from biogas : recent advances in catalyst reusability and water content effect

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    Altres ajuts: acords transformatius de la UABThe valorization of biogas as a renewable energy source faces a major obstacle regarding its purification. Siloxane is one of the impurities that cause problems such as damages to equipment of combustion engines, turbines, and boilers used for biogas conversion to heat and electricity. In this review, adsorption for siloxane removal is widely discussed, with two specific approaches: adsorbents sensitivity to water and regeneration, two essential points for industrial application. Thus, determining factors in adsorbents capacity, reusability, and water tolerance including textural properties, surface functional groups, and hydrophobicity are deeply analyzed. Studies oriented to the optimization of traditional adsorbents such as activated carbon, silica gel, and aluminosilicates as well as newly emerging adsorbents such as metal organic frameworks, graphene oxides, and waste-derived materials are studied in detail in terms of reusability and water tolerance. Although activated carbon is commercially used, its low selectivity, pore blockage due to siloxane polymerization, and unsuccessful regeneration make it disadvantageous. Silica gel, however, shows better reusability as a result of less adsorbent-adsorbate dissociation energy. In addition, aluminosilicates, despite its low adsorption capacity, proved to be more practical for real biogas due to their high hydrophobicity. Graphene oxide cost and energy efficiency in their synthesis make them more industrially appealing candidates despite their low adsorption capacity. Finally, metal organic frameworks demonstrated high selectivity, high adsorption capacity, and more efficient regeneration and therefore have more advantages and less drawbacks, although the number of published studies is still limited

    Biološka i serološka karakterizacija virusa tikvica u Jugoslaviji

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    A survey on summer squash open field crops was carried out during 2000 and 2001 in order to identify the major viruses infecting these crops in different localities. Plants showed different types of symptoms: mild mosaic, chlorotic spotting, distinctive mosaic, blistering of leaf lamina leaf yellowing, deformation of leaf lamina, knobbed fruits and stunting of plants. The symptoms were very variable but showed the viral nature of the investigated summer squash diseases. The collected samples were tested by bioassay and by two serological methods ELISA and EBIA using cucumber mosaic cucumovirus (CMV), zucchini yellow mosaic potyvirus (ZYMV), watermelon mosaic potyvirus 2 (WMV-2), zucchini yellow flack potyvirus (ZYFV) watermelon mosaic potyvirus 1 (WMV-1), squash mosaic comovirus (SqMV) and cucurbit aphid-borne yellows polerovirus (CABYV) polyclonal antisera. In all tested samples single or mixed infection with ZYMV, CMV and WMV-2 was detected. The most prevalent virus infecting summer squash was ZYMV. This is the first report of ZYMV, the most destructive virus infecting cucurbits, in Yugoslavia. It was also proven that the identified viruses are transmissible by Aphis gossypii in a non-persistent manner, but possible role of seed in virus transmission was not confirmed.U toku 2000. i 2001. godine izvršen je pregled useva tikvica za jelo da bi se identifikovali osnovni virusi infektivni za tikvice u različitim lokalitetima. Biljke su pokazivale različite simptome: blagi mozaik hlorotičnu pegavost, izraženi mozaik, klobučavost liske, žućenje lista deformacije liske, bradavičaste izraštaje na plodu i kržljavost biljaka. Simptomi su veoma varijabilni i na osnovu njih se ne može obaviti determinacija virusa prouzrokovača oboljenja. Sakupljeni uzorci su testirani biotestom, kao i sa dve serološke metode, ELISA i EBIA korišćenjem poliklonalnih antiseruma na cucumber mosaic cucumovirus (CMV), zucchini yellow mosaic potyvirus (ZYMV), watermelon mosaic potyvirus 2 (WMV-2) zucchini yellow flack potyvirus (ZYFV), watermelon mosaic potyvirus 1 (WMV-1), squash mosaic comovirus (SqMV) i cucurbit aphid-borne yellows polerovirus (CABYV). U svim ispitivanim uzorcima dokazana je pojedinačna ili mešana infekcija sa ZYMV, WMV-2 i CMV. Najčešće infekcije su bile sa ZYMV. Ovaj virus, jedan od najdestruktivnijih virusa na vrežastim kulturama, prvi put je konstatovan u našoj zemlji. Takođe je utvrđeno da se identifikovani virusi prenose na neperzistentan način vašima Aphis gossypii, a moguća uloga semena u pojavi oboljenja nije potvrđena

    Identifikacija virusa infektivnih za običnu tikvu (Cucurbita pepo L.) u Jugoslaviji

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    This study was carried out in order to identify the major viruses infecting pumpkins (Cucurbita pepo)grown in Serbia. Leaf samples from virus-infected pumpkin plants were collected in mid-July 2001. Naked-seeded and hulled oil pumpkins, patty pan, zucchini and summer squash from three different locations were included (Table 1). Virus-infected plants showed different symptoms (Table 2 and Figures 1-4). Due to the great variability of the symptoms, the causal viruses could not be fully and precisely determined by visual examination only. The infected samples were tested by the biotest, as well as by two serological methods, ELISA and EBIA. Polyclonal antibodies raised against cucumber mosaic cucumovirus (CMV), zucchini yellow mosaic potyvirus (ZYMV), watermelon mosaic potyvirus 1 (WMV-1), watermelon mosaic potyvirus 2 (WMV-2) and squash mosaic comovirus (SqMV) were used. In each of the 50 collected samples one or two viruses were detected (Tables 3 and 4). The most prevalent viruses infecting pumpkins were ZYMV (62%) and CMV (58%). WMV-2 was extremely rare.Cilj ovih istraživanja bio je da se identifikuju najvažniji virusi tikava (Cucurbita pepo L) gajenih u Srbiji. Uzorci biljnog materijala uljane tikve-golice, uljane tikve sa ljuskom, tikvice za jelo, patisona i cukinija koji su bili zaraženi virusima, sakupljeni su u tri lokaliteta sredinom jula 2001. godine (tab. 1). Biljke zaražene virusima pokazivale su različite simptome (tab. 2 i sl. 1-4). Tačna determinacija virusa samo na osnovu simptoma nije moguća zbog varijabilnosti samih simptoma. Zaraženi uzorci su testirani biotestom kao i primenom dve serološke metode, ELISA i EBIA korišćenjem poliklonalnih antitela na Cucumber mosaic cucomovirus (CMV) Zucchini yellow mosaic potyvirus (ZYMV), Watermelon mosaic potyvirus 2 (WMV-2), Watermelon mosaic potyvirus 1 (WMV-1) i Squash mosaic comovirus (SqMV). U 50 ispitanih uzoraka detektovan je jedan ili dva virusa (tab. 3 i 4). Preovlađujući virusi tikava bili su ZYMV (62%) i CMV (58%). WMV-2 je detektovan u veoma malom broju uzoraka

    First Salmonella spp. prevalence study in pigs and pork products from the province of Córdoba, Argentine

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    The study of the prevalence of Salmonella spp. in the pig and pork production chain is important to reduce the risk of spreading this pathogen into the human population. The aim of this study was to estimate the prevalence of Salmonella spp. in pigs and pork products from Córdoba. Mesenteric lymph nodes samples from 580 finishing pigs from different pig farms , and 420 samples (83 batches) of fresh pork products (the so-called “chorizo fresco de cerdo”) from different retailers were analyzed. ISO 6579:2002 standard protocol was used for Salmonella isolation. Prevalence of Salmonella spp. in finishing pigs in Córdoba was 41.5% (95%CI 37.6%- 45.6%). According to pig´s origin the province was split in North, Central and South region. The prevalence observed in each region was 49.5%, 43.0% and 36.0% respectively. The significantly higher prevalence observed in the North may be associated with the precarious conditions of the pig production sector in that area, compared to the better pig producing practices in the southern region. Prevalence of Salmonella spp. in fresh pork products was 17.4% (95%CI 15.8%-23.4%). Based on the Argentine Food Codex criteria, 34/83 (40.9%) of the analyzed batches should be rejected given the presence Salmonella spp. positive. In addition, total coliforms were also analyzed on these pork samples following national legislation and 42 (63.0%) of the batches should have been rejected according to coliform total count. Overall, only 13% of the batches fulfilled both criteria for acceptance. In conclusion, the high prevalence of Salmonella spp. in pig farms and of Salmonella spp. and coliforms in these type of pork products suggested important safety breakdowns along the pig production and pork elaboration processes. An important effort should be done to reach suitable hygienic and sanitary standards for pig and pork production in the province of Córdoba

    Resistance to colistin and production of extended-spectrum ß-lactamases and/or AmpC enzymes in Salmonella isolates collected from healthy pigs in Northwest Spain in two periods: 2008-2009 and 2018

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    Salmonellosis is a common subclinical infection in pigs and therefore apparently healthy animals may represent a reservoir of antibiotic-resistant Salmonella for humans. This study estimates and characterizes resistance to two classes of antimicrobials considered of the highest priority within the critically important antimicrobials for humans, i.e. colistin (CR) and 3rd generation cephalosporins (3GC), on a collection of Salmonella isolates from pigs from two periods: between 2008 and 09, when colistin was massively used; and in 2018, after three years under a National Plan against Antibiotic Resistance. Prevalence of CR was low (6 out of 625; 0.96%; 95%CI: 0.44–2.1) in 2008–09 and associated mostly to the mcr-1 gene, which was detected in four S. 4,5,12:i:- isolates. Polymorphisms in the pmrAB genes were detected in a S. 9,12:-:- isolate. No CR was detected in 2018 out of 59 isolates tested. Among 270 Salmonella isolates considered for the assessment of resistance to 3GC in the 2008–2009 sampling, only one Salmonella Bredeney (0.37%; 95%CI: 0.07–2.1) showed resistance to 3GC, which was associated with the blaCMY-2 gene (AmpC producer). In 2018, six isolates out of 59 (10.2%; 95%CI: 4.7–20.5) showed resistance to 3GC, but only two different strains were identified (S. 4,12:i:- and S. Rissen), both confirmed as extended-spectrum β-lactamases (ESBL) producers. The blaCTX-M-3 and blaTEM-1b genes in S. 4,12:i:- and the blaTEM-1b gene in S. Rissen seemed to be associated with this resistance. Overall, the prevalence of CR in Salmonella appeared to be very low in 2008–2009 despite the considerable use of colistin in pigs at that time, and seemed to remain so in 2018. Resistance to 3GC was even lower in 2008–2009 but somewhat higher in 2018. Resistance was mostly coded by genes associated with mobile genetic elements. Most serotypes involved in these antimicrobial resistances displayed a multidrug resistance pattern and were considered zoonotic

    Crop rotations sustain cereal yields under a changing climate

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    Agriculture is facing the complex challenge of satisfying increasing food demands, despite the current and projected negative impacts of climate change on yields. Increasing crop diversity at a national scale has been suggested as an adaptive measure to better cope with negative climate impacts such as increasing temperatures and drought, but there is little evidence to support this hypothesis at the field scale. Using seven long-term experiments across a wide latitudinal gradient in Europe, we showed that growing multiple crop species in a rotation always provided higher yields for both winter and spring cereals (average +860 and +390 kg ha−1 per year, respectively) compared with a continuous monoculture. In particular, yield gains in diverse rotations were higher in years with high temperatures and scant precipitations, i.e. conditions expected to become more frequent in the future, rendering up to c. 1000 kg ha−1 per year compared to monocultures. Winter cereals yielded more in diverse rotations immediately after initiation of the experiment and kept this advantage constant over time. For spring cereals, the yield gain increased over time since diversification adoption, arriving to a yearly surplus of c. 500 kg ha−1 after 50-60 years with still no sign of plateauing. Diversified rotations emerge as a promising way to adapt temperate cropping systems and contribute to food security under a changing climate. However, novel policies need to be implemented and investments made to give means and opportunities for farmers to adopt diversified crop rotations

    The transcriptome of soybean reproductive tissues subjected to water deficit, heat stress, and a combination of water deficit and heat stress

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    Global warming and climate change are driving an alarming increase in the frequency and intensity of extreme climate events, such as droughts, heat waves, and their combination, inflicting heavy losses to agricultural production. Recent studies revealed that the transcriptomic responses of different crops to water deficit (WD) or heat stress (HS) are very different from that to a combination of WD + HS. In addition, it was found that the effects of WD, HS, and WD + HS are significantly more devastating when these stresses occur during the reproductive growth phase of crops, compared to vegetative growth. As the molecular responses of different reproductive and vegetative tissues of plants to WD, HS, or WD + HS could be different from each other and these differences could impact many current and future attempts to enhance the resilience of crops to climate change through breeding and/or engineering, we conducted a transcriptomic analysis of different soybean (Glycine max) tissues to WD, HS, and WD + HS. Here we present a reference transcriptomic dataset that includes the response of soybean leaf, pod, anther, stigma, ovary, and sepal to WD, HS, and WD + HS conditions. Mining this dataset for the expression pattern of different stress response transcripts revealed that each tissue had a unique transcriptomic response to each of the different stress conditions. This finding is important as it suggests that enhancing the overall resilience of crops to climate change could require a coordinated approach that simultaneously alters the expression of different groups of transcripts in different tissues in a stress-specific manner
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