Involvement of heme synthesis in the growth stimulation of maize seedlings by 5‐aminolevulinic acid

The growth of maize seedlings was stimulated by shoot‐applied 5‐aminolevulinic acid 2 days after treatment at 90 and 120 μmol L^?1. The effects of 5‐aminolevulinic acid on the activity of nitrate reductase (EC 1.6.6.2) and nitrite reductase (EC 1.7.7.1) and the chlorophyll, ammonium, heme and total free amino acid content were investigated by using maize seedlings to clarify the involvement of nitrogen metabolism and heme synthesis in the growth stimulation. 5‐Aminolevulinic acid increased the level of nitrate reductase activity at 90 μmol L^?1 and the ammonium and heme content at 90 and 120 μmol L^?1 2 days after treatment. The total amino acid content increased by 90 and 150 μmol L^?1 5‐aminolevulinic acid 2 and 3 days after treatment, respectively. However, no significant change was observed in the activity of nitrite reductase or the chlorophyll content after the 5‐aminolevulinic acid treatment. These results suggest that the enhancement of nitrogen metabolism by nitrate reductase activation is involved in the 5‐aminolevulinic acid‐induced stimulation of maize seedling growth. The activation of nitrate reductase might be related to an increase in the heme content following the 5‐aminolevulinic acid treatment.     

Health-beneficial effects of probiotics: Its mode of action

It is now widely recognized that probiotics have health-beneficial effects on humans and animals. Probiotics should survive in the intestinal tract to exert beneficial effects on the host's health. To keep a sufficient level of probiotic bacteria in the gastrointestinal tract, a shorter interval between doses may be required. Although adherence to the intestinal epithelial cell and mucus is not a universal property of probiotics, high ability to adhere to the intestinal surface might strongly interfere with infection of pathogenic bacteria and regulate the immune system. The administration of probiotic Lactobacillus stimulated indigenous Lactobacilli and the production of short-chain fatty acids. This alteration of the intestinal environment should contribute to maintain the host's health. The immunomodulatory effects of probiotics are related to important parts of their beneficial effects. Probiotics may modulate the intestinal immune response through the stimulation of certain cytokine and IgA secretion in intestinal mucosa. The health-beneficial effects, in particular the immunomodulation effect, of probiotics depend on the strain used. Differences in indigenous intestinal microflora significantly alter the magnitude of the effects of a probiotic. Specific probiotic strains suitable for each animal species and their life stage as well as each individual should be found.     

Immunohistochemical analysis of cyclooxygenase-2 induction during wound healing in dog skin

Cyclooxygenase (COX)-2 is an inducible isoform of COX and is expressed under abnormal health conditions. This study elucidated the cutaneous induction of COX-2 during the wound healing processes in dog skin. Dog skin was sutured after punch biopsy and investigated histologically and immunohistochemically on days 0 (normal), 1, 3, 5, 7, 10, and 14 after injury. Histological changes, including infiltration of inflammatory cells and proliferation of fibroblast-like cells, were observed as predicted, and there was a close and significant correlation between these 2 events. COX-2-positive cells were detected in the epidermis between days 1 and 7, and bimodal peaks were observed in the case of the percentage of COX-2-positive cells. In inflammatory cells, COX-positive signals were detected on day 3 only. Here, we clarified the localization and pattern of the induced COX-2 expression during wound healing in dog skin.     

Effect of simulated acid fog on membrane-bound calcium (mCa) in fir (Abies firma) and cedar (Cryptomeria japonica) mesophyll cells

The decline of virgin fir (Abies firma) forest at Mt. Oyama has been reported. Related field observations suggest that high acidity fog is linked with its decline. However, cedar (Cryptomeria japonica) in the same area shows no symptoms of decline. For assessing effects of acid fog on membrane-bound calcium (mCa) of the leaf mesophyll cells, 9-year-old seedlings of fir (Abies firma) and 8-year-old seedlings of cedar (Cryptomeria japonica) were exposed twice a week to simulated acid fog (SAF at pH 3 with pH 5 as control) for 2 h per day in a chamber during May–December 2007 (except August). Current and 1-year-old needles were collected from seedlings and analyzed at 1-month intervals. For current-year needles of fir, mCa levels in cells exposed to SAF at pH 3 were significantly lower than in cells exposed to pH 5, especially during September 2007–March 2008. In contrast, it is noteworthy that mCa levels of cedar were maintained as virtually constant irrespective of SAF acidity, indicating that fir is more sensitive to acid fog than is cedar. Based on these results, mCa loss by acid fog might also be caused in the declining virgin fir forest at Mt. Oyama.     

High-resolution mapping revealed a 1.3-Mbp genomic inversion in Ssi1, a dominant semidwarf gene in rice (Oryza sativa)

Dwarf or semidwarf characters are an important trait for crop breeding as they provide lodging resistance. The rice mutant line DMF-1 has a dm-type semidwarf phenotype and high-lodging resistance controlled by the dominant gene, Short second internode 1 ( Ssi1 ). To elucidate the mechanism of reducing culm length in DMF-1, we sought to identify the Ssi1 gene by positional cloning using the chromosome segment substitution line as a crossing parent. As a result of high-resolution mapping, we found a 1.3-Mbp genomic inversion and a newly arranged gene in the Ssi1 locus. In this study, we report the high-resolution mapping and physical mapping of Ssi1 . We also discuss the possible function of a novel rearranged Ssi1 gene for the dominant dm-type semidwarf phenotype.     

Vertical behavior of bigeye tuna (Thunnus obesus) in the northwestern Pacific Ocean based on archival tag data

The behavior of bigeye tuna (Thunnus obesus) in the northwestern Pacific Ocean was investigated using archival tag data for 28 fish [49–72 cm fork length (FL) at release, 3–503 days] released in Japanese waters around the Nansei Islands (24–29°N, 122–132°E) and east of central Honshu (Offshore central Honshu, 32–36°N, 142–148°E). Vertical behavior was classified into three types based on past studies: ‘characteristic’ (non‐associative), ‘associative’ (associated with floating objects) and ‘other’ (behavior not fitting into these two categories). The proportion of fish showing associative behavior decreased and that of characteristic behavior increased as fish grew, and this shift was pronounced at 60–70 cm FL. The fish usually stayed above the 20°C isotherm during the daytime and nighttime when showing associative behavior and below the 20°C isotherm during daytime for characteristic behavior. A higher proportion of characteristic behavior was seen between December and April around the Nansei Islands, and between September and December for offshore central Honshu. Seasonal changes in vertical position were also observed in conjunction with changes in water temperature. In this study, ‘other’ behavior was further classified into five types, of which ‘afternoon dive’ behavior, characterized by deep dives between around noon and evening, was the most frequent. The present study indicated that in the northwestern Pacific Ocean, the vertical behavior of bigeye tuna changes with size, as well as between seasons and regions.     

Comparisons among MRI signs,apparent diffusion coefficient,and fractional anisotropy in dogs with a solitary intracranial meningioma or histiocytic sarcoma

Although MRI has become widely used in small animal practice, little is known about the validity of advanced MRI techniques such as diffusion‐weighted imaging and diffusion tensor imaging. The aim of this retrospective analytical observational study was to investigate the characteristics of diffusion parameters, that is the apparent diffusion coefficient and fractional anisotropy, in dogs with a solitary intracranial meningioma or histiocytic sarcoma. Dogs were included based on the performance of diffusion MRI and histological confirmation. Statistical analyses were performed to compare apparent diffusion coefficient and fractional anisotropy for the two types of tumor in the intra‐ and peritumoral regions. Eleven cases with meningioma and six with histiocytic sarcoma satisfied the inclusion criteria. Significant differences in apparent diffusion coefficient value (× 10^?3 mm²/s) between meningioma vs. histiocytic sarcoma were recognized in intratumoral small (1.07 vs. 0.76) and large (1.04 vs. 0.77) regions of interest, in the peritumoral margin (0.93 vs. 1.08), and in the T2 high region (1.21 vs. 1.41). Significant differences in fractional anisotropy values were found in the peritumoral margin (0.29 vs. 0.24) and the T2 high region (0.24 vs. 0.17). The current study identified differences in measurements of apparent diffusion coefficient and fractional anisotropy for meningioma and histiocytic sarcoma in a small sample of dogs. In addition, we observed that all cases of intracranial histiocytic sarcoma showed leptomeningeal enhancement and/or mass formation invading into the sulci in the contrast study. Future studies are needed to determine the sensitivity of these imaging characteristics for differentiating between these tumor types.     

Involvement of circadian clock in crowing of red jungle fowls (Gallus gallus)

The rhythmic locomotor behavior of flies and mice provides a phenotype for the identification of clock genes, and the underlying molecular mechanism is well studied. However, interestingly, when examining locomotor rhythm in the wild, several key laboratory‐based assumptions on circadian behavior are not supported in natural conditions. The rooster crowing ‘cock‐a‐doodle‐doo’ is a symbol of the break of dawn in many countries. Previously, we used domestic inbred roosters and showed that the timing of roosters' crowing is regulated by the circadian clock under laboratory conditions. However, it is still unknown whether the regulation of crowing by circadian clock is observed under natural conditions. Therefore, here we used red jungle fowls and first confirmed that similar crowing rhythms with domesticated chickens are observed in red jungle fowls under the laboratory conditions. Red jungle fowls show predawn crowing before light onset under 12:12 light : dim light conditions and the free‐running rhythm of crowing under total dim light conditions. We next examined the crowing rhythms under semi‐wild conditions. Although the crowing of red jungle fowls changed seasonally under semi‐wild conditions, predawn crowing was observed before sunrise in all seasons. This evidence suggests that seasonally changed crowing of red jungle fowls is under the control of a circadian clock.     

东北坡耕地春季融雪侵蚀观测研究

为研究东北地区坡耕地的春季融雪侵蚀特征及其影响因素,选取吉林省吉兴小流域内坡耕地进行原位观测,通过分析融雪过程中径流量和含沙量的变化,以及融雪径流、土壤解冻深度等指标对融雪侵蚀的影响,探讨坡耕地融雪侵蚀过程及变化规律。结果表明,在日平均温度0~3.8℃的气象条件下,春季融雪侵蚀较为集中,径流与含沙量变化均先增加后减少。融雪径流与表层土壤解冻深度是影响融雪侵蚀的重要因素,初期融雪产流,土壤未解冻,径流急剧增加,径流量占融雪期总径流量的59.15%;中期积雪融化趋于稳定,土壤表层开始解冻,径流减少含沙量增加,侵蚀量达到最大且占融雪期总侵蚀量的41.74%;末期融雪产流停止,土壤解冻深度增加,含沙量达到最大(8.00kg/m~3)。坡耕地融雪侵蚀受垄作区域与集水洼地地形变化的影响,产流产沙具有较强规律性,二者峰值出现频次一致时,径流—泥沙呈"8"字循环滞后关系,反之呈复式循环滞后关系。     

Analysis of the role of forest,biomass policy legislation and other factors that may affect the future of Kenya’s forests: Use of Japanese forestry as a model

Forests are one of the most important ecosystems on earth that require careful management, conservation, and sustainable exploitation. As countries have their own guideline systems, each may learn and borrow from one another’s experience. One of such countries is Japan, which has elaborate forest policies, and rich in forest cover (67%) with its forest history dating many years back. On the other hand, Kenya, with a forest cover of just 7% and its policies demonstrating notable weaknesses, has a lot to learn from Japan. Therefore, we have attempted to do a comparative analysis of forest policies, technologies, and management practices between Kenya and Japan. Results indicate that Kenya’s forest policies do not place adequate emphasis on silvicultural practices and the establishment of forest plantations, and rarely focus on sustainable biomass utilization—factors that contributed significantly to forest growth and development in Japan. Additionally, policy legislation, revision, and implementation have not been given the deserved priority in Kenya. We conclude that Kenyan forest policy would benefit from both revision and thorough implementation. We also discuss the role of indirect factors such as economic growth and availability of nonwood-based energy sources in the future of Kenya’s forests.