Intranuclear coccidiosis in tortoises: nine cases

Chelonian intranuclear coccidiosis has been reported once, in two radiated tortoises (Geochelone radiata), and is apparently rare. We describe intranuclear coccidiosis diagnosed histologically in two radiated tortoises, three Travancore tortoises (Indotestudo forstenii), two leopard tortoises (Geochelone pardalis), one bowsprit tortoise (Chersina angulata), and one impressed tortoise (Manouria impressa). Infection was systemic and involved alimentary, urogenital, respiratory, lymphoid, endocrine, and integumentary systems. Trophozoites, meronts, merozoites, macrogametocytes, microgametocytes, and nonsporulated oocysts were seen histologically or by electron microscopy. Intracytoplasmic and extracellular stages of parasite development also were identified histologically. Sequencing of a coccidial 18S rRNA consensus polymerase chain reaction (PCR) product revealed a novel sequence that provided phylogenetic information and may be useful for further diagnostic test design. Intranuclear coccidiosis was associated with variable degrees of inflammation in all cases, was considered the cause of death in six tortoises, and was a substantial contributing factor to the cause of death in two tortoises.     

Wood ash effects on nutrient dynamics and soil properties under Mediterranean climate

Aims

This study aims to evaluate the effects of wood ash application on nutrient dynamics and soil properties of an acidic forest soil (Arenosol).

Methods

Treatments were loose and pelleted ash application (11?Mg?ha^?1), alone or together with N fertiliser, and control treatment in a lysimeter experiment. Nutrient leaching was followed during a 2-year period and soil chemical and biological properties were evaluated at the end of the experiment.

Results

Wood ash increased leaching of total N, NH ₄ ⁺ -N, base cations and P, mainly during the first months, the effect being more pronounced for the loose formulation. At the end of the study period, a positive effect on soil nutrient availability and soil acidity reduction was seen. The application of loose and pelleted ash alone decreased N leaching and increased N microbial biomass at the end of the experiment. The C dynamics was weakly affected.

Conclusion

Wood ash can be used to improve nutrient availability and balance nutrient exported by tree harvesting in acid forest soils, the effects at short-term being stronger for loose than for pelleted ash. However, their application should be carried out when vegetation is established to minimise nutrient losses at short-term and reduce the potential risk for water bodies. In N-limited soils, wood ash should be applied with N fertilisers to counteract N immobilisation.     

Monitoring responses of forest to climate variations by MODIS NDVI: a case study of Hun River upstream,northeastern China

This study analyzed the temporal variation of Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) of Hun River upstream forest in northeastern China and its correlation with climate parameters (temperature and precipitation) during the period of 2000–2009. We examined the interannual variation of forest, seasonal variation of forest and lag effects of climate variables (temperature and precipitation) on forest using simple regression and correlation. The objective of this paper was to compare the results of our research and previous researches and to show that the conclusions derived from broad-scale researches provided a direction of policy, but the local details were essential to local management. We found that the annual mean NDVI was significantly correlated with annual mean temperature. The forests studied in our research showed insignificant increase trends except for Fraxinus spp. forest. We concluded that the temperature was the limiting factor of vegetation growth in our study area and the forest which was in the core geographic area of its distribution was resilient to climate variation. When seasonal variation was examined, we found the largest increase trend of seasonal mean NDVI was in winter. The result was different from the outcome of previous research at national scale. There were 3 months lag effects of climate variables on vegetation of our study area in summer and autumn, which was consistent with researches at broad scales. The reasons of both difference and indifference were discussed in this paper. We also got information about tree species for local management using MODIS NDVI. The results of this work suggested that information from local scales would be important complements to researches at broad scales and were essential for local managers.     

Observation of skyrmions in a multiferroic material

A magnetic skyrmion is a topologically stable particle-like object that appears as a vortex-like spin texture at the nanometer scale in a chiral-lattice magnet. Skyrmions have been observed in metallic materials, where they are controllable by electric currents. Here, we report the experimental discovery of magnetoelectric skyrmions in an insulating chiral-lattice magnet Cu(2)OSeO(3) through Lorentz transmission electron microscopy and magnetic susceptibility measurements. We find that the skyrmion can magnetically induce electric polarization. The observed magnetoelectric coupling may potentially enable the manipulation of the skyrmion by an external electric field without losses due to joule heating.     

Vitamin C Enhances the In vitro Development of Porcine Pre‐implantation Embryos by Reducing Oxidative Stress

Vitamin C (Vc) is a natural compound supplemented to culture media to guarantee the appropriate reactive oxygen species (ROS) level, as well as protect cells from oxidative damage and apoptosis. The current study was conducted to determine the effects of Vc (0, 2.5, 5, 10, 20 and 40 μg/ml) on the ROS production, developmental ability and quality of in vitro produced porcine parthenotes. The results show that: (i) the ROS levels in the embryos significantly decrease in the Vc‐treated groups compared with the control (p < 0.05), (ii) the rates of blastocyst formation and total cell numbers in each blastocyst are significantly higher in the Vc‐treated groups than in the control (p < 0.05); the optimum concentration of Vc is 20 μg/ml, (iii) the relative expression of Bcl‐xL significantly increases and that of Bax is downregulated after Vc treatment. Terminal deoxynucleotidyl transferase‐mediated dUTP nick‐end labelling analysis indicates that the ratio of apoptotic cells in the blastocyst is also significantly lower in Vc‐treated groups (p < 0.05) and (iv) Vc treatment can also increase the expression of the Nanog gene in porcine embryos, with a fivefold increase in 20 μg/ml Vc treatment compared with the control (p < 0.05). Therefore, Vc improves the development of porcine embryos by reducing the ROS levels. Vc addition in PZM‐3 medium can decrease the number of apoptotic cells and increase the cell numbers in blastocysts to produce high‐quality porcine embryos in vitro.     

Effects of different activation regimens on pronuclear formation and developmental competence of in vitro-matured porcine oocytes after intracytoplasmic sperm injection

To improve the activation protocol for in vitro-maturated porcine oocytes after intracytoplasmic sperm injection (ICSI), we examined the combined effect of U0126, a specific inhibitor of mitogen-activated protein kinase kinases, and an electrical pulse on pronuclear formation and developmental competence. Two approaches were tested: (i) 6-h treatment of ICSI oocytes with U0126 applied at different intervals (0, 2, 3 or 4 h) after the electrical pulse and (ii) treatment of ICSI oocytes with U0126 applied 4 h after the electrical pulse over an additional 4, 6 or 8 h. Another protein kinase inhibitor, 6-dimethylaminopurine, was used as a chemical activator in control experiments. The highest rates of diploid embryo formation, normal fertilization and blastocyst formation were observed after 6 h of exposure to U0126 starting 4 h after the electrical pulse. Therefore, U0126 can be used as an activating agent for porcine oocytes fertilized by ICSI.     

Relationship between apoptosis and proliferation in granulosa and theca cells of cystic follicles in sows

To investigate the causes of the occurrence and persistence of porcine cystic follicles, we evaluated the apoptosis and proliferation of follicular cells in these cysts. Apoptotic frequencies were examined by TUNEL assay and the expression of apoptosis regulators (XIAP, bax, bc1-2 and caspase-3) by immunohistochemistry, Western blotting and real-time quantitative PCR; cell proliferation activity was evaluated by PCNA immunohistochemistry and proliferation of in vitro cultured granulosa and theca cells. The low apoptotic frequency and weak proliferative activity were found in cystic follicles. Low frequency of apoptosis might be associated with decreased amounts of apoptotic-related factors (bax and caspase-3) and increased amounts of anti-apoptotic factors (XIAP and bcl-2) in cystic follicles. Significantly lower proliferation activity was detected in granulosa and theca cells from cystic follicles, and lesser PCNA-positive cells were found in cystic follicles. Our results indicate that the programmed cell death and cell proliferation system were altered in cystic follicles. The disorder between apoptosis and proliferation was responsible for maintaining a static condition without degeneration, which leads to the long-term persistence of follicles. These findings provide important novel insights into the pathogenesis of follicular cysts in sows.     

Effects of an aqueous alfalfa extract on production performance, egg quality and lipid metabolism of laying hens

The present study was conducted to evaluate the effect of an aqueous alfalfa extract (AAE) on production performance, egg quality and lipid metabolism of laying hens between 28 and 36 weeks of age. Four groups of commercial hens (Hy-Line Brown) were fed with diets containing 0, 0.05%, 0.1% and 0.15% AAE. Dietary AAE had no effect on egg production parameters (p > 0.05). Shell strength was increased (linear and quadratic effects; p < 0.05) with gradient addition of AAE. Furthermore, shell strength was notably higher (p < 0.05) in 0.1% and 0.15% AAE groups than the control group. With an exception of serum low and high density lipoprotein cholesterol, serum total triglycerides and liver cholesterol concentration (day 42), lipid indices in yolk, serum and liver were lowered (linear and quadratic effects; p < 0.05) at day 42 and day 56 as AAE in diets increased, as well as the enzyme activities of acetyl-CoA carboxylase (ACC) and β-hydroxy-β-methylglutaryl-CoA (HMG-CoA) reductase. In relation to the control group, cholesterol and triglycerides in yolk, liver and serum and serum very low density lipoprotein cholesterol were lower in 0.15% AAE-treated birds at day 42 and day 56. It also significantly decreased activities of ACC, HMG-CoA reductase and fatty acid synthetase (FAS) at day 56. The 0.1% AAE decreased triglycerides in yolk, liver and serum, as well as the activities of ACC and FAS at day 56. These data suggest that dietary AAE could be applied to improve egg shell quality and modify the lipid status of laying hens and eggs.