Water temperature does not affect protein sparing by dietary carbohydrate in Senegalese sole (Solea senegalensis) juveniles

The effect of dietary protein reduction balanced by an increase in carbohydrate (starch) level on growth performance, feed utilization and intermediary metabolism of Senegalese sole juveniles was evaluated at two temperatures, 12 and 18°C. For that purpose two isolipidic (16% lipids) diets were formulated to contain 550gkg^?1 protein and 90gkg^?1 starch (diet HP:LC), and 450gkg^?1 protein and 200gkg^?1 starch (diet LP:HC). Each experimental diet was fed to triplicate groups of 20 fish (initial body weight: 15.9g) within each temperature. Diets had no effect on growth and feed utilization. Temperature affected growth but not feed efficiency, with fish growing more at 18°C. Fatty acid synthetase and glutamate dehydrogenase activities were higher at 12°C than at 18°C while activity of the other measured enzymes was not affected by water temperature. Glucokinase and malic enzyme activities were lower while fructose 1,6‐bisphosphatase activity was higher in fish fed the HP:LC diet. Our data suggest that protein can be reduced from 550 gkg^?1 to 450 gkg^?1 by increasing starch level in high lipid diets for Senegalese sole juveniles without affecting overall performance. A reduction in protein content through an increase in dietary starch decreases hepatic gluconeogenesis. Increasing temperature from 12°C to 18°C improves fish growth but does not affect feed efficiency.     

Effect of thinning on above-ground biomass accumulation in a Douglas-fir plantation in southern Italy

We investigated the effects of a long-term thinning experiment on the distribution of above-ground biomass of Douglas-fir(Pseudotsuga menziesii [Mirb.]Franco var. menziesii) in a plantation in southern Italy.Allometric equations were used to estimate biomass and partitioning to stem and crown compartments. Variation in biomass stock estimated with allometric equations were evaluated according to seven thinning treatments: geometric-systematic(1 row every 3), selective(light-moderate-heavy), mixed systematic-selective(1 row every 4, 1 row every 5), unthinned(control). Over the experimental period of 13 years, current annual increments of carbon were lower(3.4 Mg ha~(-1)year~(-1)) in control plots than in treated plots. At age 30, plots subjected to light selective thinning showed higher values of above-ground biomass(249.7 Mg ha~(-1)). The biomass harvested with this treatment was 29.3 Mg ha~(-1), and the mean annual increment of carbon over 13 years was 4.8 Mg ha~(-1). Our results showed that light thinning stimulated increase in carbon stock, with a minimal loss of carbon during the treatment and a current annual increment of carbon higher than in control sub-plots and sub-plots thinned using systematic methods. This treatment yielded least carbon emissions and we affirm it has discrete global warming mitigation potential.     

Runoff,soil loss,and nutrient depletion under traditional and alternative cropping systems in the Transmexican Volcanic Belt,Central Mexico

In the Transmexican Volcanic Belt a traditional fallow system is practiced, called “ año y vez ” (AV), which does not benefit soil conservation due to its low level of nutrient recycling and because soil protection is poor during the cultivation year. The objective of the present work was to measure runoff and soil and nutrient losses during three annual cycles (2002–2004) in Central Mexico under AV rotation and two alternative systems: improved traditional (IT) and traditional organic (TO). Soil losses in the three systems were moderate (<1.2 Mg ha⁻¹ y⁻¹) except during 2002, in which significant soil losses were recorded in IT and TO due to the scarcity of plant cover (<20 per cent) that was present throughout the rainy season. During the resting period of the AV system (2003), the annual runoff increased from 19 to about 600 per cent, compared to IT and TO without grazing. The difference in runoff was attributed to an 18 per cent increase in bulk density of soil surface (0–5 cm) caused by cattle trampling while grazing. Nutrient losses in the three treatments were mainly of N, Ca²⁺, Mg²⁺, Na⁺, and K⁺. These results suggest that AV has a higher topsoil degradation effect during the resting year than during the cultivation period. The study shows that incorporating the maize/beans‐black oat rotation and residue cover causes a low runoff response that is important in reducing soil degradation. A spatial analysis is presented of erosion at watershed level for two soil management systems assessed. Copyright © 2009 John Wiley & Sons, Ltd.     

Effects of dexmedetomidine combined with ropivacaine on sciatic and femoral nerve blockade in dogs

Objective

To evaluate motor and sensory blockade of combining dexmedetomidine with ropivacaine, administered perineurally or systemically, for femoral and sciatic nerve blocks in conscious dogs.

Evaluation of the Leishmania recombinant K39 antigen as a diagnostic marker for canine leishmaniasis and validation of a standardized enzyme-linked immunosorbent assay

Canine infections with Leishmania infantum are important as a cause of serious disease in the dog and as a reservoir for human visceral leishmaniasis (VL). Accurate diagnosis of canine infections is essential to the veterinary community and for VL surveillance programs. A standardized ELISA using a purified recombinant antigen (rK39) specific to VL was compared to the immunofluorescent antibody test (IFAT) as the standard. The ELISA was developed, optimized and evaluated using sera from 6368 dogs. The standardized ELISA and IFAT results were highly concordant. The timing and pattern of ELISA and IFAT seroconversion in dogs followed prospectively after natural infections were very similar. Antibodies reacting with rK39 were more common in asymptomatic canine infections than reported for subclinical human VL. The rK39 ELISA is a relatively simple and rapid assay for assessing the infection status of dogs, and is an alternative to IFAT, especially when screening large numbers of samples.     

Characterization of an Extracellular Serine Protease of Fusarium eumartii and its Action on Pathogenesis Related Proteins

Proteases have been proposed as part of the invasion strategies of some pathogenic fungi. In this work, a serine protease produced by the phytopathogenic fungus Fusarium solani f.sp. eumartii was purified and characterized. Purification of the enzyme was accomplished by gel filtration through a Superose 12 column, followed by hydrophobic interaction chromatography in Phenyl Superose and gel filtration chromatography through Superdex 75. Analysis of the purified enzyme by SDS/PAGE without heat treatment, revealed a single band, which corresponded to the proteolytic activity detected by zymogram. When this protein was subjected to denaturing conditions, two major polypeptides of approximately 30 and 33kDa were revealed. The N-terminal amino acid sequence of one of these polypeptides showed a high similarity with fungal mature serine proteases of the subtilisin family. This protease hydrolysed in vitro, specific polypeptides of potato intercellular washing fluids and cell walls. The protease was also able to degrade pathogenesis-related proteins from the intercellular washing fluids. The role of this serine protease as part of the fungal strategy to colonize potato tuber tissues is discussed.     

Urea treatment reduced Heterobasidion annosum s.l. root rot in Picea abies after 15 years

Stump protection using chemical or biological agents is the main control measure against root and butt rot caused by Heterobasidion annosum s.l. in northern and temperate conifer forests. Long-term effects of urea treatment of stumps are poorly known and here we describe a 15-year study of urea treatment on the rot incidence on Norway spruce (Picea abies). We also tested the effect of urea protection on tree growth and on the resistance of stands against strong winds. Four treatments were made in two replications in two first-rotation P. abies stands in southern Sweden; after first-thinning stumps were (i) treated with urea 35% (w/v), (ii) artificially infected with H. annosum conidia, (iii) half urea treated and half artificially conidia infected, (iv) untreated, therefore naturally infected. After 15 years, the trees were sampled at 20 cm above ground using an increment borer and observed for presence of rot and, following incubation, presence of H. annosum conidia. Tree growth was calculated by measuring the diameter before and after the treatment. Urea treated plots showed the lowest incidence of rot (3%) as well as of H. annosum incidence (0%). Conidia treatment showed the highest incidence of rot (68%), its incidence was higher than that observed in natural infection treatment (43%), but did not differ from that of the 50% conidia treatment (47%). On about 30% of the rotted trees we observed conspicuous H. annosum fruiting. We did not observe growth reduction associated with tree rot. H. annosum was the only fungus observed associated with rotted trees which suggest that it was responsible for most of the rot observed in the investigated plots. Urea treated plots showed the lowest incidence of windthrown trees, and 59% of the windthrown tree incidence among the plots was explained by the incidence of H. annosum. Urea can be regarded as a reliable long-term protection method against root and butt rot of Norway spruce.     

Metazoan parasites of the stomach of Dissostichus eleginoides Smitt 1898 (Pisces: Notothenidae) from southern Chile: A tool for stock discrimination?

The taxonomic composition of the metazoan parasites found in the stomach of 629 specimens of the “Patagonian toothfish” Dissostichus eleginoides Smitt, 1898, from two localities in southern Chile (Lebu 36°00′S; Quellón 48°49′S), is recorded. More than 58,000 parasite specimens belonging to 9 taxa were registered. Adult worms were represented by the hemiurids Gonocerca phycidis Manter 1925, Lecithochirium genypteri Luhe 1905, Brachyphallus crenatus (Rudolphi 1802), and Derogenes varicus (Muller 1784) and the nematode Hysterothylacium sp. Ward & Magath 1917. Larval forms of anisakid nematodes, an acanthocephalan (Corynosoma sp.), a trypanorhynch cestode (Hepatoxylon trichiuri (Holten 1802)) and an unidentified pseudophyllidean cestode were also obtained. Parasitological evidence, based on univariate and multivariate analysis, does not support either the existence of discrete stocks, migratory movements between areas or seasonality in pattern of infection.