Fatty acid utilization during the early larval stages of Florida pompano (Trachinotus carolinus) and Common snook (Centropomus undecimalis)

The pattern of conservation and loss of fatty acids from the yolk sac during the endogenous feeding period and subsequent starvation was studied in pompano and snook larvae. Fundamental information on the early fatty acid dynamic and mobilization of pompano and snook larvae was collected. In both species, fatty acids were utilized as an energy source after hatching. Mono‐unsaturated fatty acids were catabolized, while saturated and poly‐unsaturated fatty acids were conserved. High levels of arachidonic acid (ARA) in pompano and snook eggs, as well as selective retention in the unfed larvae suggest a high dietary requirement for this fatty acid during the early stages of larval development. The effect of an ARA supplementation was therefore investigated in snook larvae at the rotifer feeding stage. The fatty acid profile of the larvae was successfully influenced to match that of wild eggs; however, no significant improvement in growth or survival was observed. Future research should be carried out over a longer period of time and include factors related to stress resistance.     

Effects of companion crops and tillage on soil phosphorus in a Brazilian oxisol: a chemical and 31P NMR spectroscopy study

Journal of Soils and Sediments - Phosphorus (P) is often the main limiting factor for plant growth in highly weathered tropical soils. Phosphate use efficiency and crop yields could be increased in...     

Two cases of feline visceral and cutaneous leishmaniosis in Spain

This paper describes clinical signs and lesions in two cases of leishmaniosis--one visceral and one cutaneous in the cat (Felis catus domesticus). The diagnosis was achieved by a combination of serology, light and electron microscopic studies. The vague nature of the clinical signs observed in both cases was particularly striking, and clinical features were similar to many other diseases commonly found in cats. Therefore, the use of various investigations to detect leishmaniosis (serum chemistry, serology and histopathology) is highly recommended in cases where clinical signs do not respond to conventional treatment.     

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.     

A method for describing the canopy architecture of coppice poplar with allometric relationships

A multi-scale biometric methodology for describing the architecture of fast-growing short-rotation woody crops is used to describe 2-year-old poplar clones during the second rotation. To allow for expressions of genetic variability observed within this species (i.e., growth potential, leaf morphology, coppice and canopy structure), the method has been applied to two clones: Ghoy (Gho) (Populus deltoides Bartr. ex Marsh. x Populus nigra L.) and Trichobel (Tri) (Populus trichocarpa Torr. & A. Gray x Populus trichocarpa). The method operates at the stool level and describes the plant as a collection of components (shoots and branches) described as a collection of metameric elements, themselves defined as a collection of elementary units (internode, petiole, leaf blade). Branching and connection between the plant units (i.e., plant topology) and their spatial location, orientation, size and shape (i.e., plant geometry) describe the plant architecture. The methodology has been used to describe the plant architecture of 15 selected stools per clone over a 5-month period. On individual stools, shoots have been selected from three classes (small, medium and large) spanning the diameter distribution range. Using a multi-scale approach, empirical allometric relationships were used to parameterize elementary units of the plant, topological relationships and geometry (e.g., distribution of shoot diameters on stool, shoot attributes from shoot diameter). The empirical functions form the basis of the 3-D Coppice Poplar Canopy Architecture model (3-D CPCA), which recreates the architecture and canopy structure of fast-growing coppice crops at the plot scale. Model outputs are assessed through visual and quantitative comparisons between actual photographs of the coppice canopy and simulated images. Overall, results indicate a good predictive ability of the 3-D CPCA model.     

Effects of crown development on leaf irradiance,leaf morphology and photosynthetic capacity in a peach tree

The three-dimensional (3-D) architecture of a peach tree (Prunus persica L. Batsch) growing in an orchard near Avignon, France, was digitized in April 1999 and again four weeks later in May 1999 to quantify increases in leaf area and crown volume as shoots developed. A 3-D model of radiation transfer was used to determine effects of changes in leaf area density and canopy volume on the spatial distribution of absorbed quantum irradiance (PAR(a)). Effects of changes in PAR(a) on leaf morphological and physiological properties were determined. Leaf mass per unit area (M(a)) and leaf nitrogen concentration per unit leaf area (N(a)) were both nonlinearly related to PAR(a), and there was a weak linear relationship between leaf nitrogen concentration per unit leaf mass (N(m)) and PAR(a). Photosynthetic capacity, defined as maximal rates of ribulose-1,5-bisphosphate carboxylase (Rubisco) carboxylation (V(cmax)) and electron transport (J(max)), was measured on leaf samples representing sunlit and shaded micro-environments at the same time that the tree crown was digitized. Both V(cmax) and J(max) were linearly related to N(a) during May, but not in April when the range of N(a) was low. Photosynthetic capacity per unit N(a) appeared to decline between April and May. Variability in leaf nitrogen partitioning between Rubisco carboxylation and electron transport was small, and the partitioning coefficients were unrelated to N(a). Spatial variability in photosynthetic capacity resulted from acclimation to varying PAR(a) as the crown developed, and acclimation was driven principally by changes in M(a) rather than the amount or partitioning of leaf nitrogen.     

Hydraulic architecture correlates with bud organogenesis and primary shoot growth in beech (Fagus sylvatica)

In beech (Fagus sylvatica L.), the number of leaf primordia preformed in the buds determines the length and the type (long versus short) of annual growth units, and thus, branch growth and architecture. We analyzed the correlation between the number of leaf primordia and the hydraulic conductance of the vascular system connected to the buds. Terminal buds of short growth units and axillary buds of long growth units on lower branches of mature trees were examined. Buds with less than four and more than five leaf primordia formed short and long growth units, respectively. Irrespective of the type of growth unit the bud was formed on, the occurrence of a large number of leaf primordia was associated with high xylem hydraulic conductance. Xylem conductance was correlated to the area of the outermost annual ring. These results suggest that organogenesis and primary growth in buds correlates with secondary growth of the growth units and thus with their hydraulic architecture. Possible causal relationships between the variables are discussed.     

Pharmacokinetic and pharmacodynamic parameters of ramipril and ramiprilat in healthy dogs and dogs with reduced glomerular filtration rate

Ramipril, an angiotensin-converting enzyme (ACE) inhibitor for use in dogs, is converted in vivo to its active form, ramiprilat, which is eliminated in the bile and urine in the dog. The objective of this study was to assess the effect of renal impairment on the pharmacokinetics (PKs) and pharmacodynamics (PDs) of ramipril and ramiprilat. Ten adult Beagle dogs were used. PK/PD studies were performed before and after the induction of subclinical renal impairment. Ramiprilat was given at 0.25 mg/kg by a single IV bolus. After a 2-week washout period, ramipril was administered PO at 0.25 mg/kg once daily for 8 days. Ramipril and ramiprilat PKs were studied by using a physiologically based model. The relationship between free plasma ramiprilat concentration and ACE activity was described by using the fractional Hill model. Glomerular filtration rate was decreased by 58%. No biologically relevant changes in usual plasma variables were observed between the 1st and the 8th day of oral treatment with ramipril under either condition. After an IV bolus of ramiprilat, the only changes in renal-impaired dogs were a 14 and 49% decrease in clearance of the free fraction of ramiprilat (P < .01) and free plasma concentration required to produce 50% of the maximal effect (P < .05), respectively. After repeated PO administration of ramipril, there were no alterations in any of the PK and PD parameters in healthy or renal-impaired dogs. No adjustment of the recommended PO dosage of ramipril is needed in dogs with moderate renal impairment.     

Three-dimensional reconstruction of partially 3D-digitized peach tree canopies

A simplified method for building three-dimensional (3D) mock-ups of peach trees is presented. The method combines partial digitizing of tree structure with reconstruction rules for non-digitized organs. Reconstruction was applied at two scales: leaves on current-year shoots (CYS) and shoots on 1-year-old shoots (OYOS). Reconstruction rules make use of allometric relationships, random sampling of shoot attribute distribution and additional hypotheses (e.g., constant internode length). The method was quantitatively assessed for two training systems (tight goblet and wide-double-Y), at a range of spatial scales. For this purpose, light interception properties of reference and reconstructed mock-ups were compared. Mock-up quality depended on scale. Foliage reconstruction on CYS was unsuitable for generating a given CYS. Similarly, CYS reconstruction on OYOS was unsuitable for generating a given OYOS. This is because generic rules derived at the population scale do not consider specific foliage or shoot attributes of a given CYS or OYOS. In contrast, foliage reconstruction on CYS was able to generate OYOS mock-ups having light properties similar to the reference mock-ups. The same held for CYS reconstruction on OYOS for light capture properties at the tree scale. The CYS reconstruction on OYOS was also suitable for deriving OYOS distribution as a function of light interception ability. Reconstruction rules were successfully used to build the vegetation neighborhood of a reference shoot. The proposed method could therefore be used to make 3D tree mock-ups usable for a range of some, but not all, light computations. Because the simplified method allows large time savings, it could be used in virtual experiments requiring large numbers of replicates, such as comparative studies of tree genotypes or training systems.     

Flavored yogurt complex viscosity influences real-time aroma release in the mouth and sensory properties

The influence of flavored yogurt texture on aroma perception and in-nose aroma release measured by atmospheric pressure chemical ionization mass spectrometry analysis was investigated. The study was carried out on six yogurts varied by protein composition and mechanical treatment. For the same matrix composition, the complex viscosity of yogurts influenced in-nose release and perception. After swallowing, aroma release and intensity of olfactory perception were stronger in low-viscosity yogurts than in high-viscosity yogurts. Moreover, the protein composition influenced aroma release only when yogurts exhibited wide variations of complex viscosity and consequently texture. In mouth, aroma release and perception were influenced more by yogurt mechanical treatment than by protein composition. On the basis of mass transfer analysis, the main physical mechanism which could explain the difference in aroma release would be the surface exchange area developed in the mouth and in the throat.