A surge-like increase in luteinizing hormone preceding musth in a captive bull African elephant (Loxodonta africana)

This study was conducted to determine the correlation between reproductive hormones and musth in a male African elephant. Changes in circulating luteinizing hormone (LH), follicle stimulating hormone (FSH), testosterone and immunoreactive (ir-) inhibin and the degree of musth were evaluated for 4 years. LH increased 4 weeks before musth began. The highest concentrations of testosterone and ir-inhibin were observed from April to October. There were positive correlations among testosterone, ir-inhibin and musth behavior. These findings suggested that the surge-like LH in the pre-musth period might stimulate secretion of testosterone and ir-inhibin and thus initiate the musth behavior. This study also suggested that the high LH level before musth might be a useful biomarker for the beginning of the musth season.     

Cerebral vascular hamartoma with thrombosis in a dog

A cerebral vascular hamartoma was identified in the frontal lobe, striatum and thalamus of the right side of the brain of a male, 7-year-old Shih Tzu. Histologically, the lesion consisted of thin-walled vessels, which showed various sizes and occasionally contained fibrin thrombi. These vascular walls were composed of a single layer of fibromuscular tissue lined by flat endothelium with various amount of collagen, but devoid of large coat of smooth muscles and elastic tissue. Immunohistochemically, the lining endothelial cells were positive for von Willebrand Factor antibody. Neuropil between the vessels was stained with Klüver-Barrera stain, and positive for synaptophysin and GFAP antibodies. Based on these findings, the lesion was diagnosed as vascular hamartoma, which might resemble venous malformation in humans.     

Application of renal microangiography to normal and diseased kidneys of cattle and mice

Use of microangiography is now essential for the study of microcirculation in various organs. Renal microangiographic studies have been reported in rats, rabbits, dogs, human beings, and mice. However, we could not find any report on use of the technique in cattle, despite high incidence of renal disease in that species. The perfusion technique used in mice was improved over that of our previous report, and was applied to normal and diseased bovine kidneys. For the microangiographic technique, composition of the contrast medium, pressure of the injection, duration of perfusion, and washing of kidneys with heparinized saline solution before perfusion are important. In cattle, 1- to 2-mm-thick sections of the kidneys were generally necessary to observe renal vasculature: arcuate and interlobular arteries, afferent arterioles, and glomerular capillaries. In normal bovine kidneys, the angiographic and microangiographic findings were easily recognized as normal, compared with those of normal mice. In affected bovine kidneys, which histologically represented glomerulonephritis and pyelonephritis, angiography and microangiography revealed corresponding findings.     

黑龙江省安达市草地碱化后土壤物理性状变化

调查了安达市盐碱地生物资源环境研究中心试验区羊草Leymus chinensis地土壤物理性状,包括土壤硬度、含水量、饱和导水率、粒径分布、剖面特征和土壤温度等.阐明土地碱化对土壤物理性质的影响,为安达市以及松嫩平原生态环境的修复和土地资源的永续利用提供科学依据.同时,讨论了地下水化学成分和土壤冻融变化对碱化的可能影响,认为在没有植被覆盖的条件下,冻融变化会加剧土壤的碱化程度.     

Generation of α‐1,3‐Galactosyltransferase‐Deficient Porcine Embryonic Fibroblasts by CRISPR/Cas9‐Mediated Knock‐in of a Small Mutated Sequence and a Targeted Toxin‐Based Selection System

The CRISPR/Cas9 system has enabled the editing of mammalian genomes; however, its applicability and efficiency in the pig genome has not been studied in depth. The α‐gal epitope synthesized by α‐1,3‐galactosyltransferase gene (GGTA1) is known as a xenoantigen obtained upon pig‐to‐human xenotransplantation. We here employed the CRISPR/Cas9 system‐mediated knock‐in of endogenous GGTA1 via targeted homologous recombination (HR). Linearized donors with ~800‐bp homology flanking the CRISPR/Cas9 target site [exon 4 (containing ATG) of GGTA1] served as a template for gene targeting by HR. Using a targeted toxin strategy to select clones lacking α‐gal epitope expression, we successfully obtained several knock‐in clones within 3 weeks of initial transfection. These results suggest that the use of CRISPR/Cas9‐mediated HR to knock‐in a mutated fragment at defined loci represents an efficient strategy to achieve the rapid modulation of genes of interest in swine cells and is a promising tool for the creation of KO piglets.     

Effects of Shifting Cultivation on Soil Ecosystems in Sarawak, Malaysia. III. Results of Burning Practice and Changes in Soil Organic Matter at Niah and Bakam Experimental Sites

The effects of burning on the levels of soil organic matter, soil nitrogen, and soil microbial biomass were studied by carrying out experimental shifting cultivation at two sites, Niah and Bakam in Sarawak, Malaysia. Vegetation biomass was burned in plots (10 × 10 m²) at the rates of 0 (control), 100, 200, and 300 Mg ha⁻¹ at the Niah site and 0, 20, and 100 Mg ha⁻¹ at the Bakam site. At the Niah site, the levels of total C and N of the soils did not change throughout the experiment in spite of enhanced soil respiration until 2 months after burning. Although burning induced an increase in the amount of NH₄-N of the soils, the readily available pool of N (the sum of the NH₄-N, NO₃-N, microbial biomass N, and extractable organic N pools) in the burned plots was depleted appreciably at the end of rice cultivation. The effects of burning on these properties tended to be substantial with increasing amounts of the vegetation biomass burned. On the other hand, the levels of total C and N and the readily available N pool at the Bakam site were low before burning compared with those at the Niah site, and the burning treatments did not affect them appreciably. While the rice yield at the Niah site reached the average value obtained in traditional shifting cultivation in Sarawak, that at the Bakam site was much lower. It was suggested that the flush of NH₄-N induced by burning was one of the major factors for rice growth.     

Influence of potassium chloride on desorption of cadmium sorbed on hydroxyaluminosilicate-montmorillonite complex

Cadmium adsorption and desorption on a synthetic hydroxyaluminosilicate-montmorillonite (HAS-Mt) complex were investigated in comparison with a montmorillonite (Mt) and hydroxyaluminum-montmorillonite (HyA-Mt) complex.

Kinetics studies of Cd adsorption on Mt, HyA-Mt and HAS-Mt complexes were conducted at pH 5.0, using a 10^-7 M Cd(NO₃)₂ solution in a solid to solution ratio of 100 mg to 100 mL. After 240 min reaction, 94, 88, 32% of the added Cd were removed from the solutions of the Mt, HyA-Mt, and HAS-Mt systems, respectively. Considering the magnitude of the cation exchange capacity of the clay and complexes, affinity of Cd ions was highest for the HAS-Mt complex.

Desorption experiment was conducted using 1 M KC1, 1 M KNO₃, and water. The desorption rate of Cd sorbed on the Mt was the highest, 90 and 59%, using KC1 and KNO₃, respectively, while, that on the HyA-Mt and HAS-Mt was around 30% and much lower than in the case of Mt, using both chemical reagents. Water could not desorb the adsorbed Cd at all. The difference in the desorption rate between KC1 and KNO₃ was due to the complex ion formation of Cd with the anionic species.

The adsorption of Cd by Mt varied with the nature of intercalated materials, namely, HyA and HAS. The extent of the desorption of Cd decreased due to intercalation of HAS and HyA. In the soil environment, Mt is commonly intercalated with HyA and/or HAS. Our data indicated that the formation of HyA- and HyA-Mt complexes should lead to Cd accumulation in soil environments. In addition, the application of potash (KC1) fertilizer would enhance the desorption of the Cd accumulated in soils.     

Effect of burning on soil organic matter content and N mineralization under shifting cultivation system of Karen people in Northern Thailand

In the traditional shifting cultivation system practiced by the Karen people in northern Thailand, the effects of burning on the content of extractable organic matter, microbial biomass, and N mineralization process of the soils were studied. Five plots (5×5 m² quadrat) with 0, 10, 20, 50, and 100 Mg ha^-1 of slashed materials were arranged and burned. Ten to 20 Mg ha^-1 of slashed biomass corresponded to the amount commonly burned by the Karen people. During the burning process, the soil temperature at the depth of 2.5 cm in the 100 Mg ha^-1 plot almost evenly increased to 300°C while the temperature in the 10 to 50 Mg ha^-1 plots increased with large variations from 50 to 300°C. Burning caused a conspicuous increase in the contents of organic C and (organic + mineral)-N extracted at room temperature and a simultaneous decrease in the contents of microbial biomass C and N, especially in the soil of the 100 Mg ha^-1 plot. In the rainy season, the values of the changes induced by burning reverted to the values recorded before burning, except for the microbial biomass in the 100 Mg ha^-1 plot, which still remained lower. Based on an incubation experiment, N mineralization rate was higher in the soils taken just after burning, especially in the 100 Mg ha^-1 plot, than in the soils taken during the rainy season. However, the soil in the 100 Mg ha^-1 plot was considered to have the lowest ability to supply mineral N among the soils in the rainy season. Burning of 10 to 20 Mg ha^-1 biomass corresponding to the values recorded in Karen peoples' shifting cultivation system was more compatible with soil ecology in terms of N supply at the initial stage of crop growth and of microbial biomass recovery during the rainy season, compared to the burning of 100 Mg ha^-1 biomass corresponding to the value recorded in a natural forest. Thus, the shifting cultivation system implemented by the Karen people can be considered to be a well-balanced agricultural system.     

Selenium in amorphous iron (hydr)oxide-applied soil as affected by air-drying and pH

Occurrence of D-amino acid has been reported in various higher plants (11, 13). However detailed aspects of the synthesis and degradation of D-amino acids in higher plants are poorly documented.