Urban sediment particle size and pollutants in Southern Brazil   总被引：1，自引：1，他引：0  

Cristiano Poleto  Edson C. Bortoluzzi  Susanne M. Charlesworth  Gustavo H. Merten 《Journal of Soils and Sediments》2009,9(4):317-327

Background, aim and scope

Studies of particulate-associated pollutants, or PAPs, in urban areas have become necessary due to their potentially deleterious effects on the environment. However, it is not just the sediments themselves which are problematic but also their particle size composition, which has a great influence on their capacity to adsorb and transport pollutants. This paper presents the particle size distributions and concentrations of five metals (Cr, Cu, Ni, Pb and Zn) of urban sediments collected from paved streets and gully pots from 20 cities in southern Brazil. The cities have different characteristics and hence sources of PAPs associated with differing geologies, soil types and type of urbanisation. Studies of this nature enable elucidation of the relationship between diffuse sources such as streets and gully pots and the likelihood of PAPs to subsequently pollute the urban aquatic environment.

Materials and methods

Sediment samples were taken at random from paved streets and gully pots in 20 cities in Rio Grande do Sul state, southern Brazil by means of a portable vacuum cleaner to avoid loss of finer particles. The particle sizes of the samples were measured using a Cilas® 1180 laser particle analyzer, and the concentrations of five metals (Cr, Cu, Ni, Pb and Zn) were determined by wet acid digestion (HCl–HF–HClO₄–HNO₃) followed by inductively coupled plasma atomic emission spectroscopy on the <63-µm fraction.

Results

It was found that in comparison to sediments collected from the streets, gully pot sediments were more heterogeneous in terms of particle size and also that sediment samples from the gully pots were predominantly coarser than those originating on the streets. From the gully pot results, analysis of the modal particle diameter enabled the cities to be divided into three categories. The concentrations of metals in the street sediments were similar across all 20 cities, with all concentrations above background values.

Discussion

The fact that concentrations of metals in the street sediments were above statutory guideline values and that the coarser material was deposited in the gully pots suggests that the finer, more polluted sediment is not retained in the gully pots but is transported to the nearest local receiving watercourse. This finding has implications for management strategies for reducing pollution in urban environments.

Conclusions

High concentrations of Cr, Cu, Ni, Pb and Zn in the <63-µm fraction of street sediments, in combination with coarse material retained in the gully pots, indicate that metals could be transferred quite rapidly from the diffuse source of pollutants, on impermeable street surfaces, to receiving watercourses.

Recommendations and perspectives

Studies of urban sediment particle size and geochemistry enable predictions to be made of sediment behaviour in urban environments. This will inform management strategies such as the possibility of including sustainable urban drainage systems in future management plans, in which it is useful to know how efficient the drainage system is from the point of view of sediment deposition in the urban aquatic environment and the potential for pollution of receiving waters.  相似文献   

Improvement in Brazilian wheat breeding: changes in developmental phases and ecophysiological traits     

Eduardo Beche  Cristiano Lemes da Silva  Matheus Henrique Todeschini  Anderson Simionato Milioli  Giovani Benin  Jose Abramo Marchese 《Euphytica》2018,214(3):56

Understanding the processes responsible for genetic progress in grain yield and relating them to the growth and developmental phases of the wheat plant are essential for improving yield potential. This study aimed to evaluate the duration of developmental phases and eco-physiological traits associated to grain yield in Brazilian wheat cultivars released in different decades. Wheat cultivars released from 1940 to 2009 were evaluated during 2010 and 2011 in Pato Branco, Paraná, Brazil. The length of the following periods was compared: sowing-emergence (SW-EM), emergence-double ridge (EM-DR), double ridge-terminal spikelet (DR-TS), terminal spikelet-anthesis (TS-ANT), anthesis-physiological maturity (ANT-PM), sowing-anthesis (SW-ANT) and sowing-physiological maturity (SW-PM). Yield components were also measured. Breeding has reduced the days until anthesis by 14.2%, while it has extended the grain-filling period by 7.6%, compared to the first cultivars released in the country, thereby contributing to a significant increase in 1000-grain weight (12.4 and 9.0% in 2010 and 2011, respectively). The TS-ANT phase was the only phase prior to anthesis exhibiting an extension from old to modern cultivars; this phase increased 1.56 °Cd syear^?1. Spike fertility index (SFI) showed increases of 37.8 and 23.8% in 2010 and 2011, respectively. Shortening of the time to flowering, shifting of critical phases of wheat development to better environmental conditions (i.e., TS-ANT phase), and selection for shorter cultivars have been directly responsible for the increase in spike dry weight at anthesis (SDWa) and SFI [i.e., grain number (GN)].  相似文献   

Antioxidant compounds and antioxidant activity in "early potatoes"   总被引：1，自引：0，他引：1  

Leo L  Leone A  Longo C  Lombardi DA  Raimo F  Zacheo G 《Journal of agricultural and food chemistry》2008,56(11):4154-4163

The antioxidant content and the antioxidant capacity of both hydrophilic and lipophilic antioxidant extracts from four "early potato" cultivars, grown in two different locations (Racale and Monteroni), were examined. There was a considerable variation in carotenoid content and weak differences in the ascorbic acid concentration of the examined cultivars of "early potato" and between the harvested locations. An increase in both methanol/water (8:2 v/v) and phosphate buffer soluble (PBS) free phenols (70%) and bound phenols (28%) in the extracts from the cultivars grown at Racale site was found and discussed. Examination of individual phenols revealed that chlorogenic acid and catechin were the major phenols present in potato tuber extracts; a moderate amount of caffeic acid and ferulic acid was also detected. The total equivalent antioxidant capacity (TEAC) was higher in the Racale extracts and a highly positive linear relationship ( R (2) = 0.8193) between TEAC values and total phenolic content was observed. The oxyradical scavenging capacity (TOSC) of methanol/water and PBS extracts of peel and whole potatoes against the reactive oxygen species (ROS) peroxyl radicals, peroxynitrite, and hydroxyl radicals was also analyzed. A highly significant linear correlation ( R (2) = 0.9613) between total antioxidant capacity (as a sum of peroxyl radicals + peroxynitrite) and total phenol content of methanol/water extracts was established. Moreover, proliferation of human mammalian cancer (MCF-7) cells was significantly inhibited in a dose-dependent manner after exposure to potato extracts. These data can be useful for "early potato" tuber characterization and suggest that the "early potato" has a potential as a dietary source of antioxidants.  相似文献   

Effects of light availability and soil flooding on growth and photosynthetic characteristics of Genipa americana L. seedlings     

Alyne Oliveira Lavinsky  Cristiano De Souza Sant&#;Ana  Marcelo Schramm Mielke  Alex-Alan Furtado De Almeida  Fábio Pinto Gomes  Solange Fran?a  Delmira Da Costa Silva 《New Forests》2007,34(1):41-50

Genipa americana L. (Rubiaceae) is a late successional neotropical fruit tree used in riparian forest restoration programs. We analyze the effects of light availability and soil flooding on the growth and photosynthetic characteristics of G. americana seedlings under nursery and natural light conditions. Two light levels (full sunlight and shade), and two levels of soil water (flooded and control) were used in the experiment. Flooding induced significant changes in the total seedling biomass (P < 0.01). The differences among water treatments were 70 and 10% at full sunlight and shade, respectively. These changes were explained by alterations in the maximum quantum efficiency of the photosystem 2 (Fv/Fm), light-saturated net photosynthetic rates (A _sat) and intrinsic water use efficiency (WUE). G. americana has high physiological plasticity in relation to the light availability and flooding, although significant interactive effects between high light exposure and soil flooding were observed in several photosynthetic and growth variables. The results highlight the importance of the synergistic effects between physical environmental variables on the establishment and growth of G. americana seedlings. In the practical point of view we can indicate that, in degraded riparian forests subjected to soil flooding, seedlings of this species should be planted under partially shaded environments.  相似文献   

Accuracy of early fetal sex determination by ultrasonic assessment in goats     

Barbosa dos Santos MH  Rabelo MC  Rocha de Aguiar Filho CR  Dezzoti CH  Reichenbach HD  Neves JP  Fernandes de Lima P  Lemos de Oliveira MA 《Research in veterinary science》2007,83(2):251-255

The objective of this study was to determine the accuracy of early fetal sex determination by ultrasonic assessment of the relative location of the genital tubercle (GT) in goats at different stages of pregnancy as well as by the identification of fetal external genitalia. Pregnant animals were divided into three experimental groups (EI: n=21, EII: n=28, EIII: n=33). In EI, fetuses (n=27) were transrectally monitored daily from days 40 to 60 of pregnancy with a linear transducer (6.0 and 8.0MHz). In EII, fetuses (n=40) were examined once between days 45 and 70 of pregnancy by transrectal ultrasonography. In EIII fetuses (n=52) between days 100 and 120 of pregnancy, were submitted to a single transabdominal ultrasonography using a convex transducer (5.0 and 7.5MHz). Regardless of fetal sex diagnosis, 15/15 (EI), 13/16 (EII) and 9/14 (EIII) of single pregnancies and 10/12 (EI), 20/24 (EII) and 21/38 (EIII) of twin pregnancies were correctly identified. The accuracy of sex identification among EI (92.6%), EII (82.5%) and EIII (57.7%) was not statistically different (P>0.05). Identification of the GT in male fetuses was possible from day 45 onward. Changes in the GT position were not observed between days 53 and 60 of pregnancy. Accuracy of fetal sexing under field conditions is high in goats when ultrasound imaging is properly timed during pregnancy and when it is performed with proper equipment by experienced operators.  相似文献   

Evaluation of Nile tilapia in monoculture and polyculture with giant freshwater prawn in biofloc technology system and in recirculation aquaculture system   总被引：1，自引：0，他引：1  

Hamilton Hisano  Phillipe T. L. Barbosa  Liliam A. Hayd  Cristiano C. Mattioli 《International Aquatic Research》2019,11(4):335-346

Biofloc technology system (BFT), recirculation aquaculture system (RAS) and polyculture promote efficient use of water, area and nutrient recycling, which are essential practices for sustainable aquaculture development. The aim of this study was to evaluate the growth, feed efficiency, biofloc composition and water quality of Nile tilapia Oreochromis niloticus (Linnaeus, 1758) in monoculture and polyculture with giant freshwater prawn Macrobrachium rosenbergii (De Man, 1906) in BFT and RAS, over a period of 30 days. Fish (n = 128; 7.29 ± 0.67 g) were distributed randomly in 16 experimental tanks (8 fish/tank). Prawn (n = 96; 0.50 ± 0.09 g) were allocated in 8 experimental tanks (12 prawn/tank) in a polyculture. The experimental design was completely randomized with four treatments with four replicates each, in a factorial design 2 × 2 (BFT and RAS vs. monoculture and polyculture). The experimental diet (28% of digestible protein; 3100 kcal kg−1 of digestible energy) was used both to fish and prawn in BFT and RAS. There was significant effect (p < 0.01) of the system and the culture for weight gain, apparent feed conversion and protein efficiency ratio. The average weight gain and apparent feed conversion of tilapia in monoculture (30.04 g and 1.39) and in polyculture (36.44 g and 1.27) were superior (p < 0.01) in BFT than in monoculture (23.64 g and 1.74) and in polyculture (24.14 g and 1.61) in RAS. Weight gain and survival of giant freshwater prawn was superior (p < 0.01) in BFT (0.43 g and 87%) compared to RAS (0.26 g and 79%). The data showed that BFT provides better growth performance responses in monoculture for Nile tilapia and in polyculture with giant freshwater prawn compared to RAS.  相似文献   

Infestation potential of Dryocosmus kuriphilus Yasumatsu, 1951 (Hymenoptera: Cynipidae) in different natural populations of Castanea sativa Miller: an experimental ex situ test     

Pierluigi Bombi  Cristiano Fedi  Marzio Zapparoli  Mario Cammarano  Gabriele Guidolotti  Emanuele Pallozzi 《国际虫害防治杂志》2019,65(2):147-153

The Asian chestnut gall wasp was accidentally introduced in Italy in 2002 and spread across Europe in the following years, becoming a serious threat for chestnut cultivations and rural economies of many countries. Exploring the variation in susceptibility of the host genetic resources is crucial to face the spreading of this pest. We used an experimental approach for testing the differential susceptibility within and between populations of European chestnut. For doing this, we compared both the infestation level and the rate of immune individuals in trees from populations of Spain, Italy, and Greece. We found that the level of infestation is not significantly different in the different provenances but that a higher rate of immune trees occur in Greece. Our results suggest that two different contingents of trees compose Greek populations: one major group of trees with the same susceptibility as the other populations and a second minor group of trees resistant to gall wasp infestation. Our data lay the basis for improving the currently adopted measures to mitigate gall wasp impacts.  相似文献   

Application of Tamarind Waste Extracts to Improve the Antioxidant Properties of Tamarind Nectars     

Souza  Danilo Santos  Souza  Jane Delane Reis Pimentel  Coutinho  Janclei Pereira  da Silveira  Tayse Ferreira Ferreira  Ballus  Cristiano Augusto  Filho  José Teixeira  Bolini  Helena Maria Andre  Godoy  Helena Teixeira 《Plant foods for human nutrition (Dordrecht, Netherlands)》2020,75(1):70-75

Plant Foods for Human Nutrition - Tamarind fruits are consumed worldwide and their seeds have an underexploited potential. We assessed the effect of the addition of a freeze-dried aqueous of...  相似文献   

Genetics for improving biological control agents: the case of entomopathogenic nematodes     

Daniel Segal  Itamar Glazer 《Crop Protection》2000,19(8-10):685-689

Genetics is a powerful means of enhancing the beneficial traits of biological control agents. This is exemplified by the enhancement of tolerance of the entomopathogenic nematode (EPN) Heterorhabditis bacteriophora towards environmental extremes. The genetic approaches taken include selection (for heat tolerance and resistance to nematicides); screening for natural isolates displaying heat tolerance; hybridization (aided by genetic markers) and mutagenesis for generating mutants displaying either desired beneficial traits or marker mutations. Genetic engineering is a most promising tool for enhancing beneficial traits in biological control agents. The success in genetic transformation of EPN opens the way for generating transgenic nematodes carrying genes conferring resistance to various environmental extremes.  相似文献   

The Selection Exerted by Oil Contamination on Mangrove Fungal Communities     

Cristiane Cipola Fasanella  Armando Cavalcante Franco Dias  Janaina Rigonato  Marli de Fátima Fiore  Fábio Lino Soares Jr  Itamar Soares Melo  Aline Aparecida Pizzirani-Kleiner  Jan Dirk van Elsas  Fernando Dini Andreote 《Water, air, and soil pollution》2012,223(7):4233-4243

Mangrove ecosystems are tropical environments that are characterized by the interaction between the land and the sea. As such, this ecosystem is vulnerable to oil spills. Here, we show a culture-independent survey of fungal communities that are found in the sediments of the following two mangroves that are located on the coast of Sao Paulo State (Brazil): (1) an oil-spill-affected mangrove and (2) a nearby unaffected mangrove. Samples were collected from each mangrove forest at three distinct locations (transect from sea to land), and the samples were analyzed by quantitative PCR and internal transcribed spacer (ITS)-based PCR-DGGE analysis. The abundance of fungi was found to be higher in the oil-affected mangrove. Visual observation and correspondence analysis (CA) of the ITS-based PCR-DGGE profiles revealed differences in the fungal communities between the sampled areas. Remarkably, the oil-spilled area was quite distinct from the unaffected sampling areas. On the basis of the ITS sequences, fungi that are associated with the Basidiomycota and Ascomycota taxa were most common and belonged primarily to the genera Epicoccum, Nigrospora, and Cladosporium. Moreover, the Nigrospora fungal species were shown to be sensitive to oil, whereas a group that was described as ??uncultured Basidiomycota?? was found more frequently in oil-contaminated areas. Our results showed an increase in fungal abundance in the oil-polluted mangrove regions, and these data indicated potential fungal candidates for remediation of the oil-affected mangroves.  相似文献