Detection of <Emphasis Type="Italic">Phytophthora nicotianae</Emphasis> and <Emphasis Type="Italic">P. palmivora</Emphasis> in citrus roots using PCR-RFLP in comparison with other methods     

Kim D. Bowman  Ute Albrecht  James H. Graham  Diane B. Bright 《European journal of plant pathology / European Foundation for Plant Pathology》2007,119(2):143-158

Phytophthora nicotianae and P. palmivora are the most important soil-borne pathogens of citrus in Florida. These two species were detected and identified in singly and doubly infected plants using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) of internal transcribed spacer (ITS) regions of ribosomal DNA. The sensitivity of the PCR-RFLP was analyzed and the usefulness of the method evaluated as an alternative or supplement to serological methods and recovery on semi-selective medium. In a semi-nested PCR with universal primers ITS4 and ITS6, the detection limit was 1 fg of fungal DNA, which made it 1000× more sensitive than a single-step PCR with primers ITS4 and DC6. The sensitivity of detection for P. nicotianae was shown to be ten-fold lower than for P. palmivora, limiting its detection with restriction profiles in plants infected by both fungal species. Phytophthora nicotianae was detected with species-specific primers in all samples inoculated with this species despite the absence of species-specific patterns in RFLP. In contrast, the incidence of detection of P. palmivora in the presence of P. nicotianae was considerably lower using plating and morphological detection methods. Due to its high sensitivity, PCR amplification of ribosomal ITS regions is a valuable tool for detecting and identifying Phytophthora spp. in citrus roots, provided a thorough knowledge of reaction conditions for the target species is established prior to the interpretation of data.  相似文献   

Financial optimisation of target diameter harvest of European beech (Fagus sylvatica) considering the risk of decrease of timber quality due to red heartwood     

Jürgen Zell  Marc Hanewinkel  Ute Seeling 《Forest Policy and Economics》2004,6(6):579-593

A mature, average stand of European beech was generated based on characteristic data of trial plots. Some 27 different strategies of target diameter harvest, were simulated for up to 80 years with the help of a distance-dependent single-tree growth simulator. The treatments were differing in the size of the target diameter, the beginning and the end of the harvest. Based on a statistical model, the probability of the occurrence of more than 30% of red heartwood at the front-side diameter was calculated for three sections of each log. Using the predicted probability, the decrease of timber quality due to red heartwood for different treatment strategies was assessed. The harvested volume and the predicted timber quality for different harvesting strategies were used to calculate the net revenue achieved in each simulation period with the help of a calculation program. The net present value for variable interest rates of the different harvesting strategies was calculated, assuming free land rent. Using a linear programming approach, optimal areas for different treatment strategies of a modelled forest of 100 ha were calculated under 4 different scenarios. The results of the optimisation showed how the increasing interest rates replaced higher target diameters out of the optimal solution. In contrast to that the treatments with higher target diameter became more important with increasing restrictions concerning budget or ecological constraints.  相似文献   

Assessment of Atmospheric Heavy Metals by Moss Monitoring with Isothecium Stoloniferum Brid. in the Fraser Valley, B.C., Canada     

Ute Pott  David H. Turpin 《Water, air, and soil pollution》1998,101(1-4):25-44

The atmospheric heavy metal pollution of the Fraser Valley, B.C., Canada was assessed in 1993 by analyzing 62 samples of the common woodland moss Isothecium stoloniferum for lead, cadmium, nickel, zinc, chromium, and manganese. The latter two metals did not show a distinct regional distribution, but lead, cadmium, nickel, and zinc showed distinct pattern along a west-east gradient. High values were found in the metropolitan Vancouver area, located in the west of the study region. Significantly lower values were recorded for mosses from the eastern more rural areas of the Fraser Valley. Metal pollutants are likely to be contained close to their emission sources by alternating south-east, north-west winds. Highest values overall were found in the North Shore Mountains, adjacent to Vancouver. This was related to higher precipitation and short range pollutant transport from the industrialized, heavily populated areas in the floodplain of the Fraser River.  相似文献   

Nutrient dynamics in an Andean forest region: a case study of exotic and native species plantations in southern Ecuador     

Quichimbo  Pablo  Jiménez  Leticia  Veintimilla  Darío  Potthast  Karin  Tischer  Alexander  Günter  Sven  Mosandl  Reinhard  Hamer  Ute 《New Forests》2020,51(2):313-334

New Forests - Information about nutrient dynamics is of upmost importance in order to contribute to the restoration of degraded forest environments in the Andes of southern Ecuador. This study aims...  相似文献   

Ecotoxicological testing of sediments and dredged material: an overlooked opportunity?     

Heise  Susanne  Babut  Marc  Casado  Carmen  Feiler  Ute  Ferrari  Benoit J. D.  Marziali  Laura 《Journal of Soils and Sediments》2020,20(12):4218-4228

Purpose

Basing decisions for the management of contaminated sediments on ecotoxicological data is still often met with skepticism by European stakeholders. These concerns are discussed as they pertain to bioassays to show how ecotoxicological data may provide added value for the sustainable management of sediment in aquatic systems.

Materials and methods

Five “concerns” are selected that are often raised by stakeholders. The ecotoxicological practice is discussed in light of the knowledge gained in recent decades and compared with chemical sediment analysis and chemical data.

Results and discussion

Common assumptions such as a higher uncertainty of biotest results for sediments compared to chemical analyses are not supported by interlaboratory comparisons. Some confusion also arises, because the meaning of biotest data is often misunderstood, questioning their significance in light of a limited number of organisms and altered test conditions in the lab. Because biotest results describe a sediment property, they should not be directly equated with an impact upon the biological community. To identify a hazard, however, the possibility of false-negative results due to the presence of contaminants that are not analyzed but are toxic is lower.

Conclusions

The cost of increased investment in ecotoxicological tests is, in our view, small compared with that of making false-negative assessments of sediment/dredged material that can ultimately have long-term environmental costs. As such, we conclude that ecotoxicological testing is an opportunity for sediment management decision-making that warrants more attention and confidence in Europe.

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Consumption of dietary salt measured by urinary sodium excretion and its association with body weight status in healthy children and adolescents     

Libuda L  Kersting M  Alexy U 《Public health nutrition》2012,15(3):433-441

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Determining leaf stomatal properties in citrus trees utilizing machine vision and artificial intelligence     

Costa  Lucas  Archer  Leigh  Ampatzidis  Yiannis  Casteluci  Larissa  Caurin  Glauco A. P.  Albrecht  Ute 《Precision Agriculture》2021,22(4):1107-1119

Precision Agriculture - Identifying and quantifying the number and size of stomata on leaf surfaces is useful for a wide range of plant ecophysiological studies, specifically those related to...  相似文献   

How does grazing intensity affect different vegetation types in arid Succulent Karoo, South Africa? Implications for conservation management     

Daniela H. Haarmeyer  Ute Schmiedel  Britta M. Bösing 《Biological conservation》2010,143(3):588-596

The Knersvlakte in the Succulent Karoo Biome (South Africa) is known for its high plant diversity and endemism. In the course of establishing a conservation area there, we assessed baseline data for future management. We investigated the effects of grazing on the vegetation in terms of species diversity and composition as well as reproduction of selected species. Data were sampled on four adjacent farms, which were ungrazed, moderately or intensively grazed by sheep and goats. The data were collected in 27 quartz and 24 non-quartz plots, representing two major habitat types of the region. Within each of the 1000-m² plots, 100 subplots of 400 cm² size were sampled. ANOVAs revealed that species richness and abundance of endemic species on quartz fields decreased with grazing. Abundance of annuals did not increase significantly due to grazing. Fidelity analyses indicated that species composition differed between grazing intensities and that the ungrazed and moderately grazed plots both contained unique locally endemic habitat specialists. Reproduction of two endemic dwarf shrubs Drosanthemumschoenlandianum and Argyrodermafissum (both Aizoaceae) increased under moderate grazing, which in the case of D.schoenlandianum was interpreted as an effect of grazing. We attribute the low number of seedlings and annuals on the moderately grazed farm to lower seasonal rainfall on these plots. From a conservation perspective, no or moderate grazing appear to be necessary to preserve plant diversity and vegetation patterns, and their underlying processes.  相似文献   

K+ channel mutations in adrenal aldosterone-producing adenomas and hereditary hypertension     

Choi M  Scholl UI  Yue P  Björklund P  Zhao B  Nelson-Williams C  Ji W  Cho Y  Patel A  Men CJ  Lolis E  Wisgerhof MV  Geller DS  Mane S  Hellman P  Westin G  Åkerström G  Wang W  Carling T  Lifton RP 《Science (New York, N.Y.)》2011,331(6018):768-772

Endocrine tumors such as aldosterone-producing adrenal adenomas (APAs), a cause of severe hypertension, feature constitutive hormone production and unrestrained cell proliferation; the mechanisms linking these events are unknown. We identify two recurrent somatic mutations in and near the selectivity filter of the potassium (K(+)) channel KCNJ5 that are present in 8 of 22 human APAs studied. Both produce increased sodium (Na(+)) conductance and cell depolarization, which in adrenal glomerulosa cells produces calcium (Ca(2+)) entry, the signal for aldosterone production and cell proliferation. Similarly, we identify an inherited KCNJ5 mutation that produces increased Na(+) conductance in a Mendelian form of severe aldosteronism and massive bilateral adrenal hyperplasia. These findings explain pathogenesis in a subset of patients with severe hypertension and implicate loss of K(+) channel selectivity in constitutive cell proliferation and hormone production.  相似文献   

A non-invasive observation parameter to complement sediment bioassays using <Emphasis Type="Italic">Myriophyllum aquaticum</Emphasis>     

René Schreiber  Anette Küster  Ute Feiler  Matthias Grote  Rolf Altenburger 《Journal of Soils and Sediments》2011,11(8):1419-1431

Purpose  

The objective of this study was to modify a sediment contact protocol to a multiwell plate exposure system which supplements measurement of the fresh weight change (FWC) using the non-invasive effective quantum yield of energy conversion at photosystem II (PS II) reaction centres (Y(II)) in parallel. Since Y(II) is a functional parameter and FWC represents a whole-plant structural response, the determination of a more pronounced response in one of these parameters may hint at the mode of action of contaminants. By the observation of Y(II) at different time points, extrapolation of effect development over time may be gained from modelling.  相似文献