Cutaneous thermal thresholds of tropical indigenes residing in Japan

The purpose of this study was to examine the deacclimatization of the cutaneous thermal sensations of tropical indigenes residing in temperate climates. Tropical indigenes (n=13) who were born and raised in tropics but had resided in Japan for 5–61 months participated in this study, along with temperate indigenes (n=11). Their cutaneous thermal thresholds for warm, cool, hot, and cold sensations were measured in 12 body regions using a thermal stimulator controlled by a Peltier element and a push button switch. Subjects pressed the button-switch as soon as they perceived a feeling of being ‘slightly warm’, ‘slightly cool’, ‘hot’, or ‘cold’ from a neutral thermal state. Our results showed that: (1) among the tropical indigenes, no significant relationship was found between the duration of their stay in Japan and their cutaneous thermal thresholds; (2) the tropical indigenes were, on average, 3.3, 3.5, 4.2, and 7.3 °C less sensitive to warm, hot, cool, and cold sensations, respectively, than the temperate indigenes (P<0.05); and (3) the inter-threshold sensory zones between cutaneous warmth and coolness, and hot and cold sensations were wider among the tropical indigenes than among the temperate indigenes. It was concluded that the nature of the heat acclimatization of the cutaneous thermal thresholds for the tropical indigenes was retained despite their residence in a temperate climate for up to 61 months, indicating that they had more blunted perceptions of both warming and cooling than the temperate indigenes.     

Effects of duration of stay in temperate area on thermoregulatory responses to passive heat exposure in tropical south-east Asian males residing in Japan

ABSTRACT: BACKGROUND: In this study, we investigated the effects of duration of stay in a temperate area on the thermoregulatory responses to passive heat exposure of residents from tropical areas, particularly to clarify whether they would lose their heat tolerance during passive heat exposure through residence in a temperate country, Japan. METHODS: We enrolled 12 males (mean +/- SE age 25.7 +/- 1.3 years) from south-east Asian countries who had resided in Japan for a mean of 24.5 +/- 5.04 months, and 12 Japanese males (age 24.1 +/- 0.9 years) . All subjects were university students who did not engage in vigorous physical or sport activities and were considered to have similar physical activity levels. Passive heat exposure was induced through leg immersion in hot water (42 [degree sign]C) for 60 minutes under conditions of 28 [degree sign]C air temperature and 50% relative humidity. RESULTS: Compared with the Japanese group, the tropical group displayed a higher pre-exposure rectal temperature (P < 0.01) and a smaller increase in rectal temperature during 60 minutes of leg immersion (P = 0.03). Additionally, the tropical group showed a tendency towards a lower total sweat rate (P = 0.06) and lower local sweat rate on the forehead (P = 0.07). The tropical group also had a significantly longer sweating onset time on the upper back (P = 0.04) compared with the Japanese groups. The tropical group who stayed in Japan for > 23 months sweated earlier on the forehead and upper back than those who stayed in Japan < 11 months (P < 0.01 and P = 0.03 for the forehead and upper back, respectively). There was a positive correlation between duration of stay in Japan and total sweat rate (r = 0.58, P <0.05), and negative correlations between duration of stay and sweating onset time on the forehead (r = -0.73, P = 0.01) and on the upper back (r = -0.66, P = 0.02). Other physiological indices measured in this study did not show any difference between the subjects in the tropical group who had lived in Japan for a shorter time and those who had lived there for a longer time. There were also no significant relationships between duration of stay and other physiological responses during 60 minutes of leg immersion (P > 0.05). CONCLUSIONS: We conclude that the nature of heat acclimatization of the sweating responses to passive heat exposure that are acquired from long-term heat acclimatization is decayed by a stay in a temperate area, as shown by the subjects in our tropical group. We did not find any evidence of a decay in the other physiological indices, indicating that heat tolerance acquired from long-term heat acclimatization is not completely diminished through residence in a temperate area for less than 4 years, although some aspects of this heat tolerance may be decayed.     

Cutaneous Warm and Cool Sensation Thresholds and the Inter-threshold Zone in Malaysian and Japanese Males

The purpose of this study was to investigate ethnic differences in cutaneous thermal sensation thresholds and the inter-threshold sensory zone between tropical (Malaysians) and temperate natives (Japanese). The results showed that (1) Malaysian males perceived warmth on the forehead at a higher skin temperature (T_sk) than Japanese males (p<0.05), whereas cool sensations on the hand and foot were perceived at a lower T_sk in Malaysians (p<0.05); (2) Overall, the sensitivity to detect warmth was greater in Japanese than in Malaysian males; (3) The most thermally sensitive body region of Japanese was the forehead for both warming and cooling, while the regional thermal sensitivity of Malaysians had a smaller differential than that of Japanese; (4) The ethnic difference in the inter-threshold sensory zone was particularly noticeable on the forehead (1.9±1.2 C for Japanese, 3.2±1.6 °C for Malaysians, p<0.05). In conclusion, tropical natives had a tendency to perceive warmth at a higher T_sk and slower at an identical speed of warming, and had a wider range of the inter-threshold sensory zone than temperate natives.     

Micropropagation and establishment of Yucca aloifolia

Regeneration from petioles and leaf blades was studied for seven genotypes of Pelargonium peltatum. Multiple adventitious shoots were produced using wide range of thidiazuron concentrations. Somatic embryos were produced from callus-derived cell suspensions from 3 genotypes, with a combination of 0.45 μM thidiazuron and 20 μM α-naphthaleneacetic acid in liquid medium. Regenerants were rooted and transferred to soil where they showed a normal phenotype. This revised version was published online in June 2006 with corrections to the Cover Date.     

习服高原与脱习服

目的:研究人体进入低氧、低气压、低温的高海拔环境后机体出现生理应激反应和习服高原的过程。并探索在高原居住若干年后返回低海拔常氧地区机体呈现脱高原习服的临床征象。方法:习服高原环境采用回顾在藏工作50年资料、摘取相关数据,青藏铁路施工中调查资料、空运部队进藏公开发表资料之汇总共5万例。脱高原习服采用曾在藏工作生活过3~50年返回平原后问卷调查2 060人(分布全国各地)的综合资料。结果:①习服高原环境方面:5万例资料显示:当人进入高原低氧环境出现生理性的调节,临床上出现轻微的高原反应。也有个别人根本无任何反应。若体内缺氧状况得不到及时改善,原属生理应激反应就转变为病理生理范畴,出现重症高原反应,进一步发展可发生急性高原肺水肿、高原脑水肿,应迅速送医院治疗,贻误会造成死亡。在已习服高原人群中若干年后有10%左右的移居者出现红细胞过度增生,血红蛋白超过210mg/L,肺动脉收缩压大于50mmHg,右心增大,呈"多血貌"的慢性高原病(蒙赫氏病)。脱高原习服方面:我们采用在西藏曾已习服高原3~50年后返回平原2 060人,分布全国各地已完成脱高原习服和正在脱高原习服者问卷调查临床征象。②脱高原习服的症状轻重及持续时间的久暂与在高原环境海拔高度、年龄及习服高原时间久暂成正相关。一般情况下三年后就可完全脱高原习服,也有极少数人1‰无法脱习服,在低原无法生活而重返高原。在脱习服人群中有200人分布在黄土高原,这里平均海拔1 000m以上,这些人反应极轻微,况三个月后就完全脱高原习服。结论:习服高原最佳选择阶梯性适应训练法进入高原。脱习服如能选择阶梯性适应到低海拔地区,则可减少脱习服时间与减轻症状。     

苯酚好氧降解菌的驯化和筛选

采用燕化集团公司炼油事业部污水厂的活性污泥为菌源 ,好氧条件下以苯酚为唯一碳源和能源驯化、筛选 ,分离出 4种高效降酚微生物 ,初步鉴定为假单胞菌属 (Pseudomonas)。通过正交实验可知 4种微生物的适宜生长条件 :AD1在温度为 30℃ ,NaCl浓度为 0 .9mol/L ,pH值为 5条件下 ,生长状况较好 ;AD2在温度为 30℃ ,NaCl浓度为 0 .3mol/L ,pH值为 5条件下 ,生长状况较好 ;AD3和AD4在温度为 30℃ ,NaCl浓度为 0 .3mol/L ,pH值为9条件下 ,生长状况较好。     

Gauging the influence of in vitro conditions on in vivo quality and performance of woody plants

Summary The tremendous diversity in techniques, timing, and facilities used to produce woody plant microcuttings for the nursery industry can result in substantial differences in the quality and performance of the same clones, depending on the producer. Evidence suggests that relatively minor procedural discrepancies that occur during the in vitro production stages as a consequence of these different production methods can determine the survival and acceptability of the plants during subsequent production. This review tracks the influence of methodologic variables during microshoot proliferation and rooting on quality of the plant, and examines the continuing repercussions for plant performance in the ex vitro environment. Presented in the Session-in-Depth Applications of Woody Plant Tissue Culture at the 41st Meeting of the Tissue Culture Association, Houston, Texas, June 10–13, 1990. This work was supported by the Illinois Agricultural Experiment Station project no. 65-0363, the Lilly Endowment, the International Plant Propagator’s Society (Eastern Region), and the Horticultural Research Institute.     

Micropropagation of the Acacia species—A review

Summary The genus Acacia comprises many species which are important for firewood. fodder, tannin, pulpwood, shelterbelts, and soil improvement. Species of Acacia are dispersed widely in tropical and subtropical regions of Australia. South America, Asia, and Africa. In the past, the majority of forest trees have been propagated through the traditional family forestry method, where trees are grown from seeds and propagated sexually. Clonal propagation through tissue culture offers an alternative to vegetative practices and has the potential to provide high multiplication rates of uniform genotypes, resulting in short-term gains. Extensive in vitro research and success have been achieved for a number of forest trees, including the Pinus, Eucalyptus, and Acacia species. Acacia mearnsii is fast becoming one of the most important trees in South African forestry. For this reason it is important to employ biotechnology to enable the industry to compete in the international market. However, for these procedures to be commercially viable, the post-culture performance in the field must be improved because the initial financial outlay is high. This review provides an overview on in vitro work done on the Acacia species.     

甲醇降解菌的分离及性质研究

对氮肥厂活污泥进行驯化筛选得到3株甲醇降解菌,可耐10,000mg/L左右的甲醇浓度,实验得出其最佳生长条件为：pH7-8、温度30℃－35℃、通气,在适宜条件下,对甲醇有较好的降解能力。     

浙江植物引种驯化研究进展与思考

引种驯化是增加植物资源的一种传统育种方法。本文从浙江省农业科学院亚热带作物研究所引种驯化研究发展回顾入手,剖析了温州植物引种结果,以方法的改进反映浙江现代引种驯化学术水平的进步,最后讨论了植物引种驯化研究的若干问题。     

长滩果引种驯化研究

长滩果系罗汉果最佳品种。原产区分布于永福和临桂县交界400—600米山区,但不适应于低丘陵和平原地区,因而不能在低丘陵和平原地区推广。为了解决这个问题。采用了(1)选择湿润和半阴的生长环境;(2)采用适应性强的砧木;(3)促成栽培;(4)加强秋旱期的科学管理等措施并取得成功,试验结果表明长滩果产量和品质达到或略超过原产区水平。