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91.
Espaa María Luisa Baret Frdric Weiss Marie 《Agricultural and Forest Meteorology》2008,148(10):1553-1562
Digital hemispherical photography poses specific problems when deriving leaf area index (LAI) over sloping terrain. This study proposes a method to correct from the slope effect. It is based on simple geometrical considerations to account for the path length variation within the canopy for cameras pointing vertically. Simulations over sloping terrain show that gap fraction increases up-slope while decreasing down-slope. As a consequence of this balance between up- and down-slope effects, effective LAI estimates derived from inversion of the Poisson model are marginally affected for low to medium slopes (<25°) and LAI (LAI < 2). However, for larger slopes and LAI values, estimated LAI values may be strongly underestimated. The proposed correction was evaluated over four forested sites located over sloping terrain. Results indicate that in these conditions (LAI between 0.6 up to 3.0, clumped canopies with relatively erectophile leaf distribution), the effect of the slope (between 25° and 36°) was moderate as compared to other potential sources of problems when deriving LAI from gap fraction measurements, including clumping, leaf angle inclination and spatial sampling. 相似文献
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Carine Hue Marie Tremblay Daniel Wallach 《Journal of Agricultural, Biological & Environmental Statistics》2008,13(3):355-365
Bayesian methods seem well adapted to dynamic system models in general and to crop models in particular, because there is
in general prior information about parameter values. The usefulness of a Bayesian approach has often been pointed out, but
actual applications are rather rare. A major difficulty is including the elements of the covariance matrix of model errors
in the treatment. We treat the specific case of balanced data and an unstructured covariance matrix. In our particular case
this is a 3 × 3 matrix. We illustrate two methods for deriving a sample from the joint posterior density for the crop model
parameters and the error covariance matrix parameters. The first method is based on importance sampling, the second on Metropolis
within Gibbs sampling. We derive an instrumental density for the former and a proposal density for the latter which are adapted
to this type of model and data. Both algorithms work well and they give very similar results. The example concerns a model
for sunflowers during rapid leaf growth. The ultimate goal is to use the model as a decision aid in predicting disease risk. 相似文献
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Chiara Bergamino Samus E. Hoey Marie de Swarte Cliona Skelly 《Veterinary radiology & ultrasound》2019,60(3):323-329
Magnetic resonance imaging fat suppression techniques are commonly used for diagnosis of canine spinal disease, however, studies comparing different techniques are currently lacking. This retrospective, methods comparison study aimed to evaluate water excitation and STIR MRI pulse sequences for visualization of canine lumbar spinal nerve roots. For inclusion, all dogs had to have dorsal planar MRI studies of the lumbar spine using both sequences. Visual grading analysis was used for scoring the following five criteria: degree of fat suppression; nerve root visualization; subjective tissue contrast; presence of noise; and overall better image quality. Scores were independently recorded by three board‐certified veterinary radiologists on two separate occasions, 3‐6 weeks apart. A total of 90 dogs were sampled. A two‐tailed t‐test showed that there were significant differences in all scored parameters (P < 0.00001), with the exception of noise (P = 0.47343), and that the water excitation sequence scored higher in all cases excluding noise. A Gwets AC kappa for intraobserver and interobserver reliability showed “almost perfect” agreement for the nerve roots in both tests (intra: k = 0.88; inter: k = 0.90). Intraobserver agreement was “substantial” for the degree of fat suppression (k = 0.68), subjective tissue contrast (k = 0.75), and overall better image quality (k = 0.76) and it was “fair” for the noise (k = 0.46). Interobserver agreement was “moderate” for the degree of fat suppression (k = 0.53), subjective tissue contrast (k = 0.63), and overall better image quality (k = 0.66) and “slight” for noise (k = 0.25). These findings supported using the water excitation pulse sequence for fat‐suppressed MRI of canine lumbar spinal nerve roots. 相似文献
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Effects of esmolol on systemic hemodynamics and heart rate variability measured using the Analgesia/Nociception Index in resuscitated piglets with Pseudomonas aeruginosa septic shock 下载免费PDF全文
Emmanuel Boselli MD PhD Matthias Jacquet‐Lagrèze MD Jean‐Yves Ayoub DVM Lionel Bouvet MD PhD Olivier Dauwalder PharmD PhD Christelle Mansour DVM Thomas Margez Eng Christian Paquet Eng Damien Restagno MSc Bernard Allaouchiche MD PhD Jeanne‐Marie Bonnet‐Garin DVM PhD Stéphane Junot DVM PhD 《Journal of Veterinary Emergency and Critical Care》2018,28(5):447-456
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Kelmer E Kelmer G Kerl ME 《The Canadian veterinary journal. La revue veterinaire canadienne》2007,48(8):852-854
A 13-year-old, intact male, golden retriever was presented for glossomegaly. A diagnosis of a caudal lingual abscess was made by fine needle aspiration under general anesthesia. The dog showed marked clinical improvement following abscess drainage. Lingual abscesses should be included as a differential diagnosis in any dog with an unexplained acute glossomegaly. 相似文献