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Mariana?BartzkeEmail author Vera?Delov Petra?Stahlschmidt-Allner Bernhard?Allner J?rg?Oehlmann 《Journal of Soils and Sediments》2010,10(3):389-399
Purpose
The objective of this study was to complement analyses according to the European Union Water Framework Directive (WFD) with a sediment toxicity analysis as part of an integrated river assessment. To this end, Hessian water courses were analyzed using the sediment quality triad concept according to Chapman with chemical analyses, in situ effect evaluations, and ecotoxicological assessments. For the ecotoxicological assessment (fish embryo toxicity test with Danio rerio), a new evaluation scheme was developed, the fish teratogenicity index (FTI), that allows for a classification of sediments into ecological quality classes compliant to the WFD. 相似文献44.
Multi-electrode 3D resistivity imaging of alfalfa root zone 总被引:2,自引:0,他引:2
Mariana Amato Giovanni Bitella Roberta Rossi Jos A. Gmez Stella Lovelli Joo J. Ferreira Gomes 《European Journal of Agronomy》2009,31(4):213-222
Information on the amount and spatial distribution of plant roots is increasingly needed for understanding and managing crop behaviour. Soil electrical resistivity (ρ) tomography has been proposed as a non-destructive method for root biomass quantification and mapping in trees but evidence is needed on the applicability of the technique at low root density and in herbaceous plants.We produced high-resolution 3D DC soil resistivity tomograms in containers with bare soil (B), and alfalfa (Medicago sativa L.) (A1) on a silt loam soil, and alfalfa on a loam (A2). Root biomass (RMD), root length density (RLD), soil electrical conductivity (EC) and water content (θ) were measured destructively.The pattern of soil resistivity matched the spatial distribution of θ in bare soil and of RMD in rooted soil. Univariate linear relations were found between ρ and θ in bare soil and between ρ, RLD and RMD in rooted soil. Across all data RMD and soil texture (P < 0.01) explained a high proportion of variability in soil resistivity.This allows to conclude that soil resistivity is quantitatively related to root biomass in herbaceous plants even at low root density (biomass < 0.001 Mg m−3), providing a basis for the development of resistivity-founded methods for the non-destructive spatial detection of root mass in situ, but the response in ρ is of the same order of magnitude as the effects of grain size and water content. Therefore in field studies reciprocal masking of low-density roots and other soil features is possible, and the effect of variation in other soil properties should be explicitly addressed. 相似文献
45.
María Susana Fortunato Sabina Baroni Ana Julieta González Jesús David Álvarez Roncancio Mariana Papalia Manuela Martinefsky Valeria Trípodi Estela Planes Alfredo Gallego Sonia Edith Korol 《Water, air, and soil pollution》2018,229(4):120
Biodegradability of chlorhexidine (CH), triclosan (TC), and benzalkonium chloride (CBA) has been tested in 18 surface water sampling points in the urban area of Buenos Aires. Sampling points were located in both the Reconquista and the Matanza-Riachuelo basins as well as in the La Plata River. High tolerance to the three disinfectants was found and indigenous strains capable of degrading CBA and TC were isolated. Neither tolerance nor biodegradation were correlated with sewage pollution. A strain that degrades CBA was identified as belonging to the genus Pseudomonas using the API20NE system and 16SRNA sequencing. In batch assays, the strain was capable of degrading 100, 200, and up to 500 mg L?1 of CBA in 10, 25, and 46 h respectively with specific growth rates (μ) of 0.56, 0.30, and 0.14 h?1. The efficiency of the process was between 99.5–98.0% in terms of compound removal and between 93.8–89.1% in terms of chemical oxygen demand (COD). The detoxification of the compound as a result of the biodegradation was assessed using Pseudokirchneriella subcapitata, Vibrio fischeri, and Lactuca sativa as test organisms. 相似文献
46.
Omar Varela Mariana Varas Donna Rattalino Franco Crabbè Mariano Ordano 《Arid Land Research and Management》2017,31(4):418-430
In deserts, shrubs determine landscape structure and influence plant productivity by creating nutrient-enriched environments. Attributes vary among shrub species, thus their contribution to soil characteristics is expected to vary as well, and nutrient input under shrub cover will depend on species attributes. We propose that plant size determines the contribution to soil chemical characteristics. Therefore, the contribution of larger species will be higher than smaller ones. Also, each species will contribute differentially for each chemical parameter. To corroborate these premises, we measured six soil chemical characteristics in areas covered by shrubs and in bare soil, as well as among five nurse species, in four sites of the Monte desert (La Rioja, Argentina). A multivariate analysis of variance (MANOVA) indicated significant variation between cover conditions and locations. Supporting previous studies, the presence of shrubs improved soil properties. Chemical concentration between soils under shrubs and bare soils, respectively, showed as mean and (SD) were: carbon(%): 0.82 (0,47), 0.52 (0.22); nitrates (ppm): 33,33 (67,36), 2.63 (0.56); phosphorous(ppm): 16.76 (25.02), 6.56 (1.92); electrical conductivity (dS m?1): 0.24 (0,43), 0.03 (0,02); pH: 6.93 (0.56), 7.62 (0.53); and water content (%): 3,17 (8.94), 2.47 (9.15). Chemical characteristics also varied according to the nurse species. Larger nurse species affected the ensemble of chemical characteristics, after controlling for cover condition and site. Larger plant species (Bulnesia retama, Prosopis torquata, and Zuccagnia punctata) were significantly associated with higher carbon and higher nitrates concentration. These results suggest that soil properties are enhanced by the size of nurse plant species. 相似文献
47.
Biofilms of Candida spp. from the ocular conjunctiva of horses with reduced azole susceptibility: a complicating factor for the treatment of keratomycosis?
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Raimunda Sâmia Nogueira Brilhante Paula Vago Bittencourt Débora de Souza Collares Castelo‐Branco Glaucia Morgana de Melo Guedes Jonathas Sales de Oliveira Lucas Pereira Alencar Rossana de Aguiar Cordeiro Mariana Pinheiro Evilázio Fernandes Nogueira‐Filho Waldemiro de Aquino Pereira‐Neto José Júlio Costa Sidrim Marcos Fábio Gadelha Rocha 《Veterinary ophthalmology》2017,20(6):539-546
48.
Rodrigo C. Silva Virgínia B. Richini-Pereira Mariana Kikuti Pâmela M. Marson 《The Veterinary quarterly》2017,37(1):23-30
Background: Canine visceral leishmaniasis (CVL) is a worldwide parasitic zoonosis caused by Leishmania (Leishmania) infantum around the world. Canids are the definitive hosts and sand flies the intermediate hosts.Objective: To test the hypothesis that a new species-specific primers (Lch14:Lch15, targeting a multiple alignment for L. infantum kDNA minicircle) is an efficient diagnostic tool for L. infantum.Methods: The presence of L. infantum DNA was assessed in blood samples of 69 stray dogs using the conventional PCR (cPCR) and quantitative PCR (qPCR). Additional 50 lymph nodes and 50 bone marrow samples (positive and negative samples for parasitological tests) from dogs from endemic and nonendemic areas for CVL were also used. Results: L. infantum strains, and all positive lymph node and bone marrow samples for parasitological test gave positive results for cPCR and qPCR, presenting analytical sensitivity of ~100 parasite mL?1. For the blood samples, 40/69 (58%; CI 95%; 46%–69%) resulted positive for L. infantum in both tests. All positive samples were confirmed by sequencing.Conclusion: This study showed the importance of the specific detection of L. infantum based on species-specific primers by molecular techniques, highlighting the application as a confirmation method in epidemiological studies and to adopt the best control measures. 相似文献
49.
Raquel Sartor Maria J Mamprim Regina F Takahira Mariana F de Almeida 《Acta veterinaria Scandinavica》2010,52(1):36
Background
Doppler ultrasonography is an important tool for evaluating hepatic portal hemodynamics. However, no study in dogs of different body weights, in the range encountered in routine clinical veterinary practice, has been reported. It can be difficult to obtain an ideal insonation angle when evaluating the main portal vein, so evaluation of the right portal vein branch has been described in humans as an alternative. The aim of this study was to analyze, through Doppler ultrasonography, the hemodynamics in the right portal vein branch in dogs of different body weights.Methods
Thirty normal dogs were divided in three groups by weight, in order to establish normal values for mean velocity, flow volume and portal congestion index of the right portal vein branch by means of Doppler ultrasonography.Results
In all dogs ideal insonation angles were obtained for the right portal vein branch. The average velocity was similar in the three groups, but the portal congestion index and the flow volume differed, showing that the weight of the dog can influence these values.Conclusion
Doppler ultrasonography for the evaluation of flow in the right branch of the portal vein could be a viable alternative, or complement, to examining the main vessel segment. This is especially so in those animals in which an ideal insonation angle for examination of the main portal vein is hard to obtain. In addition, the weight of the dog must be considered for the correct evaluation of the portal system hemodynamics, particularly for portal blood flow and the congestion index. 相似文献50.
María A. Chiesa Rosanna N. Pioli Mariana V. Cambursano Eligio N. Morandi 《European journal of plant pathology / European Foundation for Plant Pathology》2013,135(2):351-362
Soybean Stem Canker (SSC), caused by Diaporthe phaseolorum var. meridionalis (Dpm), is an important disease of soybean in Argentina. There are five known dominant genes that confer resistance to SSC, Rdm1 to Rdm5. Particularly, Rdm2 was identified in cv. Tracy-M and then it was stabilized in the breeding line T2. The Rdm4 gene was first identified in cv. Hutcheson. More recently it was found that this gene was linked to the Rdm5 gene, defining the Rdm4-5 resistance region in Hutcheson. The objective of this work was to analyze the behaviour of the dominant Rdm2, Rdm4 and Rdm5 genes interacting with the CE109 and CE112 local physiological races of Dpm, in different susceptible backgrounds (genotypes RA702 and J77-339). Rdm4 and Rdm5 segregated phenotypically as completely dominant genes in the specific interactions with the CE109 and CE112 isolates, respectively, in both susceptible backgrounds. Similarly, Rdm2 segregated as expected for a complete dominant gene in the specific interaction with the CE109 isolate, in both susceptible backgrounds. However, when interacting with the CE112 isolate, the Rdm2 gene did not segregate as expected for a completely dominant gene, neither in RA702 nor in J77-339 susceptible background. The distorted segregation of the Rdm2 gene was due to incomplete penetrance. To the best of our knowledge this is the first report documenting changes in the degree of penetrance of a soybean resistance gene (Rdm2) depending upon the physiological race of Dpm which interacts with and the genetic background in which the Rdm gene is being expressed. 相似文献