Influence of waterlogging on carbon stock variability at hillslope scale in a beech forest (Fougères forest — West France)

The Kyoto protocol [39] directs the signatory countries including France to establish an inventory of carbon stocks in forests. Precise estimates of carbon stocks are hampered by local spatial variability, in particular in wetland areas [25]. The aims of this work are: (i) to estimate the spatial variability of carbon stocks on two hillslopes presenting respectively, a transition between a well-drained zone and a wetland area over a short-distance, and a very progressive transition; (ii) to correlate this variability with soil waterlogging and topographic variations and (iii) to evaluate carbon stock prediction by modelling waterlogging intensity as soil organic carbon (SOC) stocks increase significantly with waterlogging. However, SOC stocks in redoximorphic soils are highly variable, particularly in zones where carbon is redistributed due to erosion and sedimentation. In the litter and the vegetation, the age and density of the stand are the main explanatory factors of C variability. Topographic modelling of the waterlogging intensity could improve the spatial estimation of SOC stocks but not of the C stocks in the humus and vegetation.     

Identifying risk factors for European stone fruit yellows from a survey

ABSTRACT European stone fruit yellows (ESFY) is becoming a major economic problem for Prunus growers in Europe. The causal agent ("Candidatus Phytoplasma prunorum") and its vector (Cacopsylla pruni) have been identified, but the present knowledge of the risk factors for this disease relies, at best, on specific experiments. To assess the relative significance of several factors correlated with ESFY incidence in the field, an exhaustive survey was performed on apricot and Japanese plum orchards in the Crau plain (France). After a preliminary multivariate exploration of the data, we used a logistic regression model to analyze and predict the cumulative number of diseased trees on the basis of a set of quantitative (age, planting density, and area of the orchard) and categorical variables (species, cultivar, and rootstock). Because of the nature of the data, we used an overdispersed binomial model and we developed a parametric bootstrap procedure based on the beta-binomial distribution to obtain confidence intervals. Our results indicated that the age, species, and cultivar of the scion were the major factors explaining the observed number of diseased trees. The planting density and the rootstocks used in the zone under study were less significant, and the area of the orchard had no effect. The residuals of the model showed that some explanatory variables had not been taken into account, because part of the remaining variability could be explained by a grower effect. The spatial distribution of the residuals suggested that one of the reasons for this grower effect was the correlation between orchards closer than 100 m, possibly caused by the flight behavior of infectious vectors.     

异源表达细菌二氢喋呤合成酶基因提高拟南芥叶酸含量的研究

植物是人体叶酸的重要来源,人体缺乏叶酸会导致贫血、新生儿神经系统疾病,还与心血管病及某些癌症的发病有关,因此提高食用作物中叶酸的含量是代谢工程的研究目标之一。本研究将从细菌中分离到的编码二氢喋呤合成酶（DHPS）基因FolP,由35S启动子驱动在拟南芥线粒体中过量表达,获得了转基因植株,转基因植株叶酸总含量比野生型对照提高了48%,表明DHPS酶对植物叶酸的合成起着调控作用。     

Simulation of the soil-water dynamics and corn yields under deficit irrigation

Summary A simulation model capable of predicting the yield response of corn to a limited water supply was developed by combining two existing mathematical models. The resulting computer model was evaluated using experimental data taken under a wide range of soil moisture conditions. The soil profile water balances was simulated using SWATRE and SUCROS was used to model the crop growth in response to environmental conditions. In addition to the integration of the two existing models, some minor changes were made to each in an effort to improve the accuracy of the combined models. The model input parameters were derived entirely from published literature. The experimental data necessary for model validation were available from irrigation studies at the Sandhills Agricultural Laboratory of the University of Nebraska. These experiments not only provided the required input soil and climatic data, but also the observed irrigation levels, soil moisture distributions and crop yield required for model validation. Initial evaluation of the computer model indicates that the combined model adequately describes crop evapotranspiration, soil moisture extraction and crop yield under a fairly wide range of soil moisture stress. Additional modifications for the prediction of leaf area expansion and senescence, especially under moisture stress, are needed to improve the accuracy of the model.     

Canine cutaneous epitheliotropic T-cell lymphoma with vesiculobullous lesions resembling human bullous mycosis fungoides

The broad spectrum of clinical signs in canine cutaneous epitheliotropic T-cell lymphoma mimics many inflammatory skin diseases and is a diagnostic challenge. A 13-year-old-male castrated golden retriever crossbred dog presented with multifocal flaccid bullae evolving into deep erosions. A shearing force applied to the skin at the periphery of the erosions caused the epidermis to further slide off the dermis suggesting intraepidermal or subepidermal separation. Systemic signs consisted of profound weight loss and marked respiratory distress. Histologically, the superficial and deep dermis were infiltrated by large, CD3-positive neoplastic lymphocytes and mild epitheliotropism involved the deep epidermis, hair follicle walls and epitrichial sweat glands. There was partial loss of the stratum basale. Bullous lesions consisted of large dermoepidermal and intraepidermal clefts that contained loose accumulations of neutrophils mixed with fewer neoplastic cells in proteinaceous fluid. The lifted epidermis was often devitalized and bordered by hydropic degeneration and partial epidermal collapse. Similar neoplastic lymphocytes formed small masses in the lungs associated with broncho-invasion. Clonal rearrangement analysis of antigen receptor genes in samples from skin and lung lesions using primers specific for canine T-cell receptor gamma (TCRγ) produced a single-sized amplicon of identical sequence, indicating that both lesions resulted from the expansion of the same neoplastic T-cell population. Macroscopic vesiculobullous lesions with devitalization of the lesional epidermis should be included in the broad spectrum of clinical signs presented by canine cutaneous epitheliotropic T-cell lymphoma.     

Lung ring-down artifact as a sign of pulmonary alveolar-interstitial disease

Three dogs with presumptive cardiogenic pulmonary edema underwent a thoracic ultrasonographic examination. Multiple ring-down artifacts involving both sides of the thorax emanating from the pleural-lung interface were detected. When clinical and radiographic signs of pulmonary edema were resolved, ring-down artifacts were not observed. The ring-down artifact may be a useful diagnostic sign for screening the lung of animals with acute respiratory distress where radiographs are not feasible.     

Thermomechanically Induced Protein Aggregation and Starch Structural Changes in Wheat Flour Dough

Various studies have been carried out on wheat flour to understand protein and starch changes when subjected to mixing and temperature constraints, but structural changes of proteins and starch at the typical moisture levels of a dough system are not fully understood. The aim of this research was to improve our understanding of (micro)structural changes at the mesoscopic level, through empirical rheology, microscopy (light and scanning electron microscopy), sequential protein extractions, and glutenin macropolymer wet weight along the mixing, heating, and cooling stages of the Mixolab assay. Studies were performed on three wheat flours with different protein contents. The rheological analysis allowed identifying the role of the proteins and the relationship between the protein content and different primary and secondary parameters obtained from the recorded curves. The progressive heating and mixing stages during the Mixolab assay resulted in a dynamic de‐ and restructuring of proteins involving interactions between the flour proteins from water soluble to SDS soluble to SDS insoluble and vice versa. The microstructure analysis with light, polarized, and scanning electron microscopy revealed the changes that proteins and starch molecules underwent during mixing, heating, and cooling. Qualitatively, the starch structural changes, swelling, and gelatinization observed by microscopic techniques showed some parallels with protein (and glutenin) content of the respective flour. Nevertheless, this tentative finding needs further confirmation by studying flour samples with large differences in glutenin content.     

Laparoscopic-assisted colopexy and sterilization in male dogs: short-term results and physiologic consequences

Objective: To describe laparoscopic‐assisted colopexy and sterilization, and evaluate outcome and effects in healthy male dogs. Study Design: Experimental study. Animals: Male Beagle dogs (n=7). Methods: A laparoscopic‐assisted, extracorporeally sutured colopexy, and sterilization by ligation and section of the testicular vessels and ductus deferens were evaluated 11 weeks after surgery. Ex vivo tensile tests were performed on the colopexy sites and loss of testicular function was assessed by monitoring serum testosterone, and by ultrasonographic and histologic examinations of the testes. Systemic inflammation and potential iatrogenic colonic functional disorders were investigated by monitoring serum C‐reactive protein (CRP) in the perioperative period and from a sulfapyridine (SP) kinetic profile obtained before and 10 weeks after surgery. Results: No intraoperative complications were recorded and clinical outcome was considered fair in all dogs. A mean tensile force of 42 N was required to disrupt colopexies. No relevant postoperative increase in CRP concentrations or changes in SP kinetics were observed. Testicular function was lost. Conclusions: Laparoscopic‐assisted colopexy achieved adhesion of the colon to the abdominal wall and testicular endocrine function and spermatogenesis were eliminated by laparoscopic castration.     

Improving strength grading of timber by grain angle measurement and mechanical modeling

Abstract

Timber strength grading has become a major issue in the European Union during the last years, due to the introduction of the Eurocode 5 and all its related standards. Currently, the most performing strength grading machines are able to locally detect the boards’ knots sizes and positions and interpret this information through adapted grading models. The best lead to improve their accuracy seems to be the introduction of new information about the boards and adapt the mechanical model to take them in account. Small grain angle causes high reduction of clear wood's mechanical properties; local value of slope of grain appears to be of high interest. The aim of this study is to quantify the additional accuracy that grain angle information can bring to an optical scanner used as a strength grading machine. A specific grading model has been developed accordingly, and the results obtained for different machine/model/loading combinations are presented. These results show that slope of grain measurement can significantly improve the accuracy of the optical scanner, for both modulus of elasticity and modulus of rupture estimations.     

Preoperative immunosuppressive therapy and surgery as a treatment for anal furunculosis

OBJECTIVES: To evaluate the efficacy of combining preoperative immunosuppressive therapy with surgical excision for treatment of anal furunculosis (AF) in dogs. STUDY DESIGN: Retrospective study. ANIMALS: Dogs (n=25) with stages 1-4 AF. METHODS: Preoperative immunosuppressive therapy was either cyclosporine A (CyA) alone or in combination with ketoconazole (Group 1; n=18), or azathioprine combined with prednisolone (Group 2; n=7). Surgical excision of residual draining tracts, cryptectomy, and anal sacculectomy were performed. Only dogs with postoperative clinical follow-up exceeding 9 months were retained for the study. RESULTS: Both immunosuppressive protocols were effective in reducing progression of AF. Subsequent draining tracts excision, cryptectomy, and anal sacculectomy were bilateral (12 dogs) or unilateral (13 dogs of which 4 had bilateral anal sacculectomy). Postoperative recovery was uneventful, except for 2 dogs that had wound breakdown. Recurrence was not observed in any of the dogs that had bilateral surgical excision and or in 9 dogs that had unilateral excision. CONCLUSION: Preoperative immunosuppressive therapy, combined with bilateral surgical resection of affected tissue consistently, resulted in resolution of AF. Four dogs that had recurrence had unilateral excision despite initial bilateral involvement, suggesting that all diseased tissue should be excised. CLINICAL RELEVANCE: These preliminary results suggest that immunosuppressive therapy before surgical excision for AF yields minimizes recurrence in dogs.