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西藏墨脱县发现长尾阔嘴鸟 总被引:3,自引:2,他引:1
正2015年10月21日,在西藏自治区墨脱县德兴乡(29°20′9.97″N,95°19′13.20″E,海拔780 m)观察到阔嘴鸟2只,该鸟体长约25 cm,顶冠及颈背黑色,头顶具蓝色小点斑,喙呈黄绿色,脸及喉部呈黄色,眼后有一黄色点斑,体呈绿色且两翼有蓝斑,尾呈楔形(图1),经鉴定为长尾阔嘴鸟(Psarisomus dalhousiae)。MacK innon等(2000)认为该鸟种分布于西藏东南部,而Bruce(2003)在《世界鸟类手册》中引用了前者的描述。然而,因缺乏实际观察记录,之后我国鸟类学者的著作中均未将长尾阔嘴鸟列为在西藏有分布的鸟类(郑光美2011)。虽 相似文献
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正2018年9月至2019年4月在河南省董寨国家级自然保护区使用红外相机监测野生动物,其中1台红外相机(位置信息:114°14′54″E,31°56′10″N,海拔268m)于2019年3月19日拍摄的一段视频中记录到1只鸫科(Turdidae)鸟类。该鸟头和颈部灰色,背部及腹部栗红色,飞羽及尾羽黑色,喙黄色。经查阅《中国鸟类图鉴》(赵欣如等2019)、《中国鸟类野外手册》(约翰·马敬能等2000)等文献,确定其为灰头鸫(Turdus rubrocanus)雄鸟。因从视频中未观察到更多该鸟的形态特征,不能确定其所属亚种。 相似文献
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儿童毒蛇咬伤的特点与程序化救治的疗效观察 总被引:2,自引:2,他引:0
目的通过分析儿童毒蛇咬伤的特点,评价程序化综合救治方法对儿童毒蛇咬伤的疗效。方法通过观察17例毒蛇咬伤儿童的临床特点,尽早进行病情预测,同时根据毒蛇咬伤的临床病情分型予程序化综合救治。监测病情变化、伤口愈合情况及平均住院时间。结果儿童毒蛇咬伤的特点为不明种类毒蛇咬伤多,症状较成人严重,易发生并发症。经过早期程序化综合救治总有效率100%,伤口渗血、肿胀明显缓解,无1例死亡,平均留观时间4.5天。结论根据儿童毒蛇咬伤特点,早期准确预测和尽快应用程序化救治能提高毒蛇咬伤疗效。 相似文献
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Boel Åström 《Plant and Soil》1991,133(1):93-100
Lettuce and wheat cultivars, differing in reaction to root inoculation with plant growth-inhibitory bacteria, were tested for sensitivity to (i) gaseous metabolites produced by deleterious, cyanogenic isolates of Pseudomonas fluorescens, and to (ii) pure cyanide. Reactions were read as shoot and/or root elongation after exposure of seedlings to the volatiles in vitro. Lettuce cultivar Salad Bowl was significantly less sensitive than cv. Montana, both to bacterial volatiles and to pure cyanide, and a similar difference between these cultivars was also obtained in greenhouse experiments where bacteria were inoculated directly on the roots. Cultivar differences were, however, not recorded, either in vitro or in the greenhouse, when the bacteria were grown on a medium which did not support cyanide production. In wheat, a difference in sensitivity to bacteria-produced volatiles was recorded between two cultivars (Drabant and Besso) differing in reaction to bacterial inoculation, but in contrast to lettuce cultivars, the wheat cultivars tested did not react differentially to pure cyanide. The results suggest that in lettuce differential sensitivity to cyanide is one factor behind cultivar differences in reaction to the bacteria tested, even though bacterial metabolites other than cyanide may contribute to the plant growth inhibition recorded. In wheat, however, differential cultivar responses to these bacteria could not be shown to be related to cyanide. 相似文献
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Ectomycorrhizas: their role in forest ecosystems under the impact of acidifying pollutants 总被引:1,自引:0,他引:1
The physiologically active lateral rootlets of all main trees in temperate forests are colonised by ectomycorrhizal fungi, forming so-called ectomycorrhizas. These symbiotic organs are the sites of exchange of nutrients, mainly P and N, provided from the fungal partner, and C from the host. Emerging from the ectomycorrhizas, fungal hyphae exploit the soil for the mobilisation and absorption of water and nutrient elements. By doing so, they connect the tree roots intimately with the soil and provide anchorage. The deposition of acidifying pollutants into forest ecosystems is a potential threat to the health and vitality of forest trees because it leads to the acidification and eutrophication of forest soils. Pollutants are also a threat to the functioning of ectomycorrhizas. Increased N concentrations in the soil lead to enhanced fungal N uptake and storage, and to enhanced N transfer to the host plants, and therefore to higher plant biomass of above ground parts. In consequence, there is a decrease of C allocation to the plant roots. This in turn leads to reduced ectomycorrhization, and to reduced production of external mycelia and fruiting bodies. Soil acidification leads to enhanced availability of Al, heavy metals, and radionuclides in the soil, all of which can be toxic to plants and fungi. Reduced growth of roots and hyphae are amongst the first symptoms. In ectomycorrhizas, the hyphae of the fungal tissues contain vacuolar polyphosphates which have the ability to bind Al, heavy metals, radionuclides and N. These electronegative polymers of phosphates represent an effective storage and detoxifying mechanism which otherwise is lacking in roots. Therefore, ectomycorrhizas have the potential to increase the tolerance of trees to acidifying pollutants and to the increased availability in the soil of toxic elements. 相似文献
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The cell interior is in constant movement, which is to a large extent determined by microtubules, thin and long filaments that permeate the cytoplasm. To move large objects, microtubules need to connect them to the site of their destination. For example, during cell division, microtubules connect chromosomes with the spindle poles via kinetochores, protein complexes on the chromosomes. A general question is how microtubules, while being bound to one structure, find the target that needs to be connected to this structure. Here we review the mechanisms of how microtubules search for kinetochores, with emphasis on the recently discovered microtubule feature to explore space by pivoting around the spindle pole. In addition to accelerating the search for kinetochores, pivoting helps the microtubules to search for cortical anchors, as well as to self-organize into parallel arrays and asters to target specific regions of the cell. Thus, microtubule pivoting constitutes a mechanism by which they locate targets in different cellular contexts. 相似文献
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Evans MR Norris KJ Benton TG 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2012,367(1586):163-169
The world is experiencing significant, largely anthropogenically induced, environmental change. This will impact on the biological world and we need to be able to forecast its effects. In order to produce such forecasts, ecology needs to become more predictive--to develop the ability to understand how ecological systems will behave in future, changed, conditions. Further development of process-based models is required to allow such predictions to be made. Critical to the development of such models will be achieving a balance between the brute-force approach that naively attempts to include everything, and over simplification that throws out important heterogeneities at various levels. Central to this will be the recognition that individuals are the elementary particles of all ecological systems. As such it will be necessary to understand the effect of evolution on ecological systems, particularly when exposed to environmental change. However, insights from evolutionary biology will help the development of models even when data may be sparse. Process-based models are more common, and are used for forecasting, in other disciplines, e.g. climatology and molecular systems biology. Tools and techniques developed in these endeavours can be appropriated into ecological modelling, but it will also be necessary to develop the science of ecoinformatics along with approaches specific to ecological problems. The impetus for this effort should come from the demand coming from society to understand the effects of environmental change on the world and what might be performed to mitigate or adapt to them. 相似文献
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Actin filaments line up acrossTradescantia epidermal cells,anticipating wound-induced divison planes
Summary This paper describes the role of actin filaments in setting up the phragmosome — the transvacuolar device that anticipates the division plane — and in forming a supracellular system that seems to override cell boundaries.
Tradescantia leaf epidermal cells were induced to divide by wounding the leaf. New division planes formed parallel to slits, and encircled puncture wounds — the new division planes lining up across cells, instead of the joints being off-set as in normal, unwounded tissue. Within 30 min after wounding, rhodamine phalloidin staining showed that a belt of fine, cortical actin filaments formed parallel to the wound. In the next stage, migration of nuclei to a wall adjacent to the wound, involved pronounced association of actin filaments with the nucleus. Migration could be inhibited with cytochalasin D, confirming the role of actin in traumatotaxis. Later still, actin strands were seen to line up from cell to cell, parallel to the wound, anticipating the future division plane. Next, actin filaments accumulated in this anticlinal plane, throughout the depth of the cell, thereby contributing to the formation of the phragmosome. The phragmosome has been shown in previous work (Flanders et al. 1990) to contain microtubules that bridge nucleus to cortex, and is now found to contain actin filaments. Actin filaments are therefore involved in the key stages of nuclear migration and division plane alignment. The supracellular basis of actin alignment is discussed.Dedicated to the memory of Professor Oswald Kiermayer 相似文献
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Alexandre Pinho Moura Geraldo Andrade Carvalho Adriano Elias Pereira Luiz Carlos Dias Rocha 《BioControl》2006,51(6):769-778
The effects of the insecticides abamectin, acetamiprid, cartap and chlorpyrifos on larvae, pupae (within the host egg) and
adults of the egg parasitoid Trichogramma pretiosum Riley (Hym.: Trichogrammatidae) were evaluated under laboratory conditions, using three standard tests described by IOBC.
When sprayed on the immature stages of this parasitoid, cartap and chlorpyrifos proved to be the most harmful insecticides,
affecting both the emergence success and parasitism capacity of this parasitoid, whereas abamectin and acetamiprid were selective.
Abamectin was harmful to adults (residue test on glass plates), slightly harmful to larvae, and moderately harmful to pupae
(sprayed on the immature stages within host eggs Anagasta kuehniella (Zeller)); acetamiprid was moderately harmful to adults, harmless to larvae, and slightly harmful to pupae; cartap was harmful
to adults, moderately harmful to larvae and harmful to pupae; chlorpyrifos to adults, harmless to larvae and harmful to pupae. 相似文献
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Tohno Y Tohno S Mahakkanukrauh P Azuma C Vaidhayakarn P Moriwake Y Ohnishi Y Minami T 《Biological trace element research》2003,91(3):217-230
To elucidate quantitative changes of Ca, P, and Mg in the arteries with aging, the authors investigated changes of the mass
ratios of Mg to Ca and P in the arteries of Japanese and Thai by inductively coupled plasma-atomic emission spectrometry.
The arteries of Japanese that were used were the thoracic and abdominal aortas, coronary, common iliac, internal iliac, external
iliac, and femoral arteries, in which very high accumulations of Ca and P occurred in old age. The arteries of Thai that were
used were the abdominal aorta, ramifying site of the abdominal aorta, coronary, common iliac, internal iliac, and external
iliac arteries.
It was found that there were extremely significant correlations both between Ca and Mg contents and between P and Mg contents
in all of the arteries of the Japanese and the Thai. With regard to the mass ratio, the mass ratios of Mg to Ca ranged from
1.5% to 2.1% in the six arteries of the Japanese, except for the thoracic aorta at 3.1%, at an advanced stage of atherosclerosis,
being similar to each other. In the arteries of the Thai, the mass ratios of Mg to Ca ranged from 1.9% to 3.0%, except for
the coronary artery at 0.5%, at an advanced stage of atherosclerosis.
The mass ratios of Mg to P ranged from 2.5% to 2.7% in the six arteries of the Japanese, except for the coronary artery at
1.8%, at an advanced stage of atherosclerosis. With regard to the arteries of the Thai, the mass ratios of Mg to P ranged
from 1.9% to 3.3%, except for the coronary artery at 0.7%, at an advanced stage of atherosclerosis. These results revealed
that both the mass ratios of Mg to Ca and Mg to P were almost similar among the arteries of Japanese and Thai, except for
the coronary arteries. Therefore, these results suggested that the inorganic deposits in the coronary arteries of Japanese
and Thai were similar to those in the intimal tunica of the thoracic aorta, whereas in the other arteries, they were similar
to those in the middle tunica of the thoracic aorta. 相似文献
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于2019年7月-2020年1月对北戴河朱鹮野化种群非繁殖期的日间活动时间分配和行为节律进行了分析。结果表明,休息(41.8%)、觅食(39.7%)和理羽(13.3%)是北戴河朱鹮非繁殖期的主要行为。在行为节律上,有3个觅食高峰、2个休息高峰和2个理羽高峰。成鸟和幼鸟行为分配相似,但成鸟的警戒和社群等其他行为比例显著较高。与野生种群相比,北戴河野化种群的觅食时间显著较少,主要原因是野生个体需要花费较多时间搜寻食物,且飞行等活动的能耗较高。朱鹮在冬季的休息和理羽行为比例高于夏秋季,觅食行为则相反,这样可以在低温和大风天气降低能耗,是对北戴河气候环境的有效适应。为了提高朱鹮对多种气候环境的适应能力,为今后北戴河朱鹮的再引入奠定基础,我们建议在冬季要确保朱鹮有充足的适宜觅食地,同时在野化网笼中进行必要的环境丰容,如在网笼内增加常绿树种和阔叶树种,部分侧网上安装防风板,或在网笼中设置防风避寒的伞棚等设施,以供朱鹮进行选择。 相似文献