An explicit stem profile model for forked and un-forked teak (Tectona grandis) trees in West Africa

Studies on stem profile of teak (Tectona grandis) hardly exist. This can be possibly attributed to the occurrence of forks that is prevalent on teak trees. Stem profile model was therefore developed for teak in West Africa, which took into account the occurrence of forks. Trees were destructively sampled from Moist Evergreen Forest (MEF), Moist Semi-deciduous Forest (MSDF), Dry Semi-deciduous Forest (DSDF) and Savannah ecological zones in both Ghana and Côte d’Ivoire for the study. A single set of parameters could be used explicitly to predict stem profile of any teak tree, irrespective of country, eco-climatic zone, edaphic variables, site index, tree age, stand density and tree competition. The model efficiency and root mean square error (in relative diameter) were calculated to be 0.97 and 0.053, respectively. The relative position of the forks along the stem bole, with respect to total tree height, was highly variable and did not follow any particular trend, except higher value for the first fork in the Moist Evergreen Forest zone. However, average tree height to the first fork decreased along the ecological gradient from MEF, MSDF and DSDF to Savannah. The extent of diameter reduction due to the forks could be predicted. Relative tree form for zero-forked, one-forked and two-forked trees was calculated to be 0.39, 0.36 and 0.33, respectively. Relative loss of stem volume due to one fork and two forks was estimated to be 6.5 and 13.9%, respectively. The measured stem volume when related to the corresponding predicted value yielded coefficient and intercept not significantly different from unity and zero, respectively, with an r² value of 0.97.     

Evaluation of the visual stress grading standard on French Spruce (Picea excelsa) and Douglas-fir (Pseudotsuga menziesii) sawn timber

? In this paper an evaluation of the visual grading standard for softwood sawn timber was made.

? In order to do so, visual grading according to EN 518 and theoretical grading according to EN 338 and EN 384 (measurements of MOE, MOR and density) were applied to lumber. Two batches of 111 and 102 French boards were graded, respectively, of Spruce (Picea excelsa) and Douglas-fir (Pseudotsuga menziesii). For the visual grading the most discriminant criterion was noted: knots, cracks, wane, etc.

? Finally, the results of the two grading methods were compared, and it was shown that the visual stress grading gave quite low results for our two French species.

     

Chitosan oligomers and copper sulfate induce grapevine defense reactions and resistance to gray mold and downy mildew

ABSTRACT Chitosan (CHN), a deacetylated derivative of chitin, was shown to be efficient in promoting plant defense reactions. CHN oligomers of different molecular weight (MW) and degree of acetylation (DA) triggered an accumulation of phytoalexins, trans- and cis-resveratrol and their derivatives epsilon-viniferin and piceid, in grapevine leaves. Highest phytoalexin production was achieved within 48 h of incubation with CHN at 200 mug/ml with an MW of 1,500 and a DA of 20% (CHN1.5/20), while oligomers with greater MW were less efficient, indicating that a specific MW threshold could be required for phytoalexin response. Treatment of grapevine leaves by highly active CHN1.5/20 also led to marked induction of chitinase and beta-1,3-glucanase activities. CHN1.5/20 applied together with copper sulfate (CuSO(4)) strongly induced phytoalexin accumulation. CuSO(4) alone, especially at low concentrations also elicited a substantial production of phytoalexins in grapevine leaves. Evidence is also provided that CHN1.5/20 significantly reduced the infection of grapevine leaves by Botrytis cinerea and Plasmopara viticola, and in combination with CuSO(4) conferred protection against both pathogens.     

Effects of dietary medium-chain triacylglycerols (tricaprylin and tricaproin) and phospholipid supply on survival, growth and lipid metabolism in common carp (Cyprinus carpio L.) larvae

The present study investigated the interaction of dietary medium-chain fatty acids (MCFA) and phospholipids (PL) on survival, growth and lipid metabolism in common carp larvae. Nine diets based on casein and dextrin and with a variable lipid part were tested in triplicate for 22 days post first feeding. The 3×3 design consisted of three triacylglycerols (3% of diet) combined with three different lipid supplements. Tested triacylglycerols were triolein (TOL), tricaprylin (TC8) and tricaproin (TC6), and lipid supplements were 2% soybean oil (low-fat diets without PL), 2% soybean lecithin (low-fat diets with 2% PL) or both 2% soybean lecithin and 6% TOL (high-fat diets with 2% PL).

In the first step, both TC6 and TC8 resulted in improved survival and growth rates compared to TOL, irrespective of the PL supply. In the second step, TC8 decreased survival and growth rates, whereas the difference between TC6 and TOL became less. Histological signs of impaired intestinal absorption of neutral lipids were evidenced in larvae fed TOL without PL and also in high-fat diets with 2% PL. The latter diets also resulted in poorer growth rates compared to low-fat diets with 2% PL. These results suggest that the quantitative PL requirement of larvae increases as the dietary level of long-chain triacylglycerols increases. Larvae fed TC6 or TC8 showed enlarged liver and hepatocyte volume and a decreased level of body neutral lipids. Based on β-hydroxybutyrate (β-HBA) measurements in whole larvae, TC8 was found to be more ketogenic than TC6. TC6 and TC8 affected differently the fatty acid profile of larval body neutral lipids. TC6 did not induce the appearance of MCFA, whereas TC8 feeding resulted in a low level of 8:0 and relatively high levels of 10:0 (3.8% of total fatty acids). Neither 8:0 nor 10:0 were found in larval polar lipids.

This study confirmed the essentiality of PL in common carp larval diets and underlines differences in the utilization of TC6 and TC8, which both initially stimulate growth during the first week, but only temporarily in the case of TC8.     

IMAGING OF A SPINAL NEPHROBLASTOMA IN A DOG

An 8-month-old German Shepherd dog was presented for investigation of pelvic limb gait abnormality. Neurolocalization indicated a T3-L3 spinal cord lesion. The myelographic appearance was of an intramedullary lesion at T9/10, but upon subsequent magnetic resonance imaging it was determined that the mass was extramedullary. A diagnosis of nephroblastoma was made on histological examination. The imaging features of this rare tumor and the differentiation of intradural-extramedullary and intramedullary masses are discussed.     

MAGNETIC RESONANCE IMAGING OF THE NORMAL FELINE BRAIN

The Purpose of this study was to produce an atlas of magnetic resonance images (MRI) of the feline brain and associated structures. The head of nine clinically normal cats was imaged in 2 or 3 anatomic planes and 3 sets of technical parameters resulting in T1, T2, and proton-weighted density images. Images were compared with anatomic texts, with preserved and sectioned feline cadaver heads, with preserved and sectioned feline brains, and with intact, sectioned, and disarticulated feline skulls for aid in identification of structures. Anatomic and neuroanatomic structures are identified on selected images in different planes as reference for MR morphology of the normal feline brain and related structures.     

Evaluation of the ability of colistin,amoxicillin (components of Potencil®), and fluoroquinolones to attenuate bacterial endotoxin‐ and Shiga exotoxin‐mediated cytotoxicity—In vitro studies

Escherichia coli is one of the major pathogens in humans and animals causing localized and systemic infections, which often lead to acute inflammation, watery diarrhea, and hemorrhagic colitis. Bacterial lipopolysaccharide (LPS) and Shiga exotoxins (Stx) are mostly responsible for such clinical signs. Therefore, highly effective treatment of E. coli infections should include both eradication of bacteria and neutralization of their toxins. Here, for the first time, we compared the in vitro ability of common antibiotics to decrease LPS‐ and Stx‐mediated cytotoxicity: colistin, amoxicillin (used separately or combined), enrofloxacin, and its metabolite ciprofloxacin. Three experimental scenarios were realized as follows: (a) the direct effect of antibiotics on endotoxin, (b) the effect of antibiotic treatment on LPS‐mediated cytotoxicity in an experiment mimicking “natural infection,” (c) the effect of antibiotics to decrease Stx2e‐mediated cytotoxicity. Two cell lines, A549 and Vero cells, were used to perform cytotoxic assays with the methyl tetrazolium (MTT) and lactate dehydrogenase leakage (LDH) methods, respectively. Colistin and amoxicillin, especially used in combination, were able to attenuate LPS toxic effect, which was reflected by increase in A549 cell viability. In comparison with other antibiotics, the combination of colistin and amoxicillin exhibited the highest boster or additive effect in protecting cells against LPS‐ and Stx2e‐induced toxicity. In summary, in comparison with fluoroquinolones, the combination of colistin and amoxicillin at concentrations similar to those achieved in plasma of treated animals exhibited the highest ability to attenuate LPS‐ and Stx2e‐mediated cytotoxicity.     

Corneal stromal sequestration in a dog

A case of corneal sequestrum in a 9-year-old Shih Tzu is reported. On the ophthalmic examination a brown-pigmented ulcer with mild edema and corneal vascularization was present. The brownish plaque was facing an inferior palpebral tumor. A superficial keratectomy followed by a grid keratotomy and removal of the palpebral mass were performed. Histological findings revealed an inflammatory cell infiltration underneath the acellular stromal layers. No melanin granules were observed. No vascular infiltration was present within the necrotic stroma. The surgical area healed and no recurrence has been reported by the owners at the time of writing. To the authors' knowledge, this is the first report of a corneal sequestrum in a dog.