Floristic and ecological differences between recent and ancient forests growing on non-acidic soils     

Delphine Sciama  Laurent Augusto  Jean-Luc Dupouey  Maya Gonzalez  Concepción Moares Domínguez 《Forest Ecology and Management》2009

The aim of this work was to investigate differences in soil chemistry and understory composition between recent forests (sites afforested in the last 170 years) and ancient forests growing on non-acidic soils. The study was carried out on hardwood forests at moderate elevation (400–600 m asl) in the Jura Mountains (N.E. France) on four main pedological substrates with different characteristics. The floristic composition of 127 stands from recent forests (n = 65) or ancient forests (n = 62) was surveyed. Some functional traits and the Ellenberg indicator values of the surveyed species were recorded. In addition, the topsoil from 30 stands was analysed. The composition of the flora was analysed by Detrended Correspondence Analysis and the species which were typical of one class of forest age were identified using a chi-square (χ²) test. The difference between forest classes for plant traits, their indicator values, or soil chemistry was tested using the generalized linear model and Bonferroni t-tests (or Kruskall–Wallis tests). The floristic composition of the ancient forests was significantly different from that of the recent forests and was characterized by a high occurrence of shrub species in recent forests. These differences were associated with higher specific leaf area, low-range seeds dispersal, and some life forms like geophytes. There was no clear difference in soil chemistry between the two classes of forests, except for δ¹⁵N values. The weakness of the difference in the soil between ancient and recent forests suggested that changes in soil chemistry caused by a former agricultural land use were not responsible for the differences in understory composition recorded. The differences in functional traits between the two forest classes supported this conclusion. We finally concluded that (i) past land use modifies the vegetation composition of current forests, even on neutral soils and that (ii) in our context, biological filters were probably responsible for these changes.  相似文献   

Odor Modification in Salmon Hydrolysates Using the Maillard Reaction     

Christelle Kouakou  Jean-Pascal Bergé  Régis Baron  Laurent Lethuaut  Carole Prost 《Journal Of Aquatic Food Product Technology》2013,22(5):453-467

The aim of this work was to study the effect of adding sugar during proteolysis to promote the Maillard reaction and mask the initial fish odor and off-flavors generated. An experimental design, based on the Doehlert plan, was used to study the influence of hydrolysis conditions (time, temperature, sugar, and antioxidant addition) on the odor characteristics of hydrolysates, soluble protein levels, and amino acid content. Results showed that the lowest level of sugar (10 g of D-xylose added to 1 kg of by-products) was enough to develop a grilled odor in hydrolysates. In the hydrolysis conditions used—i.e., enzyme inactivation at 95°C for 30 min—hydrolysis temperature had no effect on grilled odor production but significantly affected the soluble protein fraction, as did hydrolysis time. Soluble protein content and essential amino acid content increased with the enzymatic reaction but were not modified by adding sugar. Hydrolysis conditions that promote Maillard reactions while keeping a nutritional balance have been identified.  相似文献   

Erratum to: Incidence and Characterization of <Emphasis Type="Italic">Potato Virus Y</Emphasis> in Seed Potatoes in Tunisia     

Sonia Boukhris-Bouhachem  J. Rouze-Jouan  N. Khamassi  Fattouma Djilani-Khouadja  Hatem Fakhfakh  Laurent Glais  Michel Tribodet  Camille Kerlan 《Potato Research》2011,54(3):283

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Whiptail Stingray Injury     

Simon Laurent  Olivier Martinet  Helene Cuq  Alain Rind  Philippe Durasnel  Claire Lenne  Renaud Blondé 《The Forestry Chronicle》2018,29(2):243-247

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An inconvenient truth about xylem resistance to embolism in the model species for refilling <Emphasis Type="Italic">Laurus nobilis</Emphasis> L.     

Laurent J. Lamarque  Déborah Corso  José M. Torres-Ruiz  Eric Badel  Timothy J. Brodribb  Régis Burlett  Guillaume Charrier  Brendan Choat  Hervé Cochard  Gregory A. Gambetta  Steven Jansen  Andrew King  Nicolas Lenoir  Nicolas Martin-StPaul  Kathy Steppe  Jan Van den Bulcke  Ya Zhang  Sylvain Delzon 《Annals of Forest Science》2018,75(3):88

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COMPARISON OF THORACIC ULTRASONOGRAPHY AND RADIOGRAPHY FOR THE DETECTION OF INDUCED SMALL VOLUME PNEUMOTHORAX IN THE HORSE          下载免费PDF全文

Jessica Partlow  Florent David  Luanne Michelle Hunt  Fabien Relave  Laurent Blond  Manuel Pinilla  Jean‐Pierre Lavoie 《Veterinary radiology & ultrasound》2017,58(3):354-360

Small volume pneumothorax can be challenging to diagnose in horses. The current standard method for diagnosis is standing thoracic radiography. We hypothesized that thoracic ultrasonography would be more sensitive. Objectives of this prospective, experimental study were to describe a thoracic ultrasound method for detection of small volume pneumothorax in horses and to compare results of radiography and ultrasound in a sample of horses with induced small volume pneumothorax. Six mature healthy horses were recruited for this study. For each horse, five 50 ml air boluses were sequentially introduced via a teat cannula into the pleural space. Lateral thoracic radiographs and standardized ultrasound (2D and M‐mode) examinations of both hemithoraces were performed following administration of each 50 ml air bolus. Radiographs and ultrasound images/videos were analyzed for detection of pneumothorax by four independent investigators who were unaware of treatment status. Sensitivity, specificity, positive predictive values, negative predictive values, and agreement among investigators (Kappa test, κ) were calculated for radiography, 2D and M‐mode ultrasound. Comparisons were made using a chi‐squared exact test with significance set at P < 0.05. Two‐dimensional (84%) and M‐mode (80%) ultrasound were more sensitive than radiography (48%) for pneumothorax detection (P = 0.02 and P = 0.04, respectively). Specificity and positive predictive values were similar for all three imaging modalities (P = 1). Agreement between investigators for pneumothorax detection was excellent for 2D ultrasound (κ = 1), very good for M‐mode ultrasound (κ = 0.87), and good for radiography (κ = 0.79). Findings from this experimental study supported the use of thoracic ultrasonography as a diagnostic method for detecting pneumothorax in horses.  相似文献   

Response of Winter Manure Application on Surface Runoff Water Quantity and Quality from Small Watersheds in South Dakota     

Shikha Singh  Nathan Brandenburg  Laurent Ahiablame  Arturo Gonzalez  Jeppe Kjaersgaard  Todd P. Trooien  Sandeep Kumar 《Water, air, and soil pollution》2017,228(10):389

Manure application on frozen soil, which is a common practice in the upper Midwest of USA, results in degraded soil and water quality. During snowmelt or precipitation events, water runoff carries nutrients into nearby streams and impairs the water quality. There is a need, therefore, to identify improved management of manure application in the soils. This study was conducted to assess water quality impacts associated following manure application during winter months when soil is completely covered with snow. The study site included three watersheds, named south (SW), east (CW), and north (NW) managed with a corn (Zea mays L.)-soybean (Glycine max L.) rotation located in South Dakota. The SW and NW were used as treatment, and CW as the control watershed. The treatments included manure application on the upper half of the SW and lower half of the NW, and CW received no manure application. This study showed that manure improved soil properties including infiltration rate and organic matter. Nitrogen and phosphorus losses in the surface runoff were higher from NW compared to that of SW. The CW had similar nutrient losses compared to the NW with slight differences. It can be concluded that maintaining a setback distance can help in improving the environmental quality as well as managing the agricultural wastes during the winter months.  相似文献   

Diuron mineralisation in a Mediterranean vineyard soil: impact of moisture content and temperature     

Talaat El Sebaı  Marion Devers  Bernard Lagacherie  Nadine Rouard  Guy Soulas  Fabrice Martin‐Laurent 《Pest management science》2010,66(9):988-995

BACKGROUND: The diuron‐mineralising ability of the microbiota of a Mediterranean vineyard soil exposed each year to this herbicide was measured. The impact of soil moisture and temperature on this microbial activity was assessed. RESULTS: The soil microbiota was shown to mineralise diuron. This mineralising activity was positively correlated with soil moisture content, being negligible at 5% and more than 30% at 20% soil moisture content. According to a double Gaussian model applied to fit the dataset, the optimum temperature/soil moisture conditions were 27.9 °C/19.3% for maximum mineralisation rate and 21.9 °C/18.3% for maximum percentage mineralisation. The impact of temperature and soil moisture content variations on diuron mineralisation was estimated. A simulated drought period had a suppressive effect on subsequent diuron mineralisation. This drought effect was more marked when higher temperatures were used to dry (40 °C versus 28 °C) or incubate (28 °C versus 20 °C) the soil. The diuron kinetic parameters measured after drought conditions were no longer in accordance with those estimated by the Gaussian model. CONCLUSION: Although soil microbiota can adapt to diuron mineralisation, its activity is strongly dependent on climatic conditions. It suggests that diuron is not rapidly degraded under Mediterranean climate, and that arable Mediterranean soils are likely to accumulate diuron residues. Copyright © 2010 Society of Chemical Industry  相似文献   

Detection of Chalara fraxinea in common ash (Fraxinus excelsior) using real time PCR     

A. Chandelier  F. André  F. Laurent 《Forest Pathology》2010,40(2):87-95

A real time PCR assay was developed for the detection of Chalara fraxinea in common ash. PCR primers and Taqman probes, based on the internal transcribed spacer region of the multi‐copy gene rDNA, were tested for specificity and sensitivity. The primers amplified an 81 bp fragment for C. fraxinea but did not amplify DNA from other Chalara species or from other fungi isolated from ash, whether pathogenic or saprophytic. The limit of detection was 5 pg of genomic DNA per PCR. Moreover, naturally‐infected samples were correctly diagnosed. A procedure for DNA extraction from woody tissues using an electric drill yielded DNA of an appropriate quality for real time PCR. This molecular method could be useful for routine analysis of this emergent pathogen and for epidemiological studies.  相似文献   

Ovine CD16+/CD14? blood lymphocytes present all the major characteristics of natural killer cells     

Jamila Elhmouzi-Younes  Preben Boysen  Daniela Pende  Anne K. Storset  Yves Le Vern  Fabrice Laurent  Fran?oise Drouet 《Veterinary research》2010,41(1)

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