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Sample records for plateau pika ochotona

  1. [Functional difference of malate-aspartate shuttle system in liver between plateau zokor (Myospalax baileyi) and plateau pika (Ochotona curzoniae)].

    Science.gov (United States)

    Zhu, Rui-Juan; Rao, Xin-Feng; Wei, Deng-Bang; Wang, Duo-Wei; Wei, Lian; Sun, Sheng-Zhen

    2012-04-25

    To explore the adaptive mechanisms of plateau zokor (Myospalax baileyi) to the enduring digging activity in the hypoxic environment and of plateau pika (Ochotona curzoniae) to the sprint running activity, the functional differences of malate-aspartate shuttle system (MA) in liver of plateau zokor and plateau pika were studied. The ratio of liver weight to body weight, the parameters of mitochondria in hepatocyte and the contents of lactic acid in serum were measured; the open reading frame of cytoplasmic malate dehydrogenase (MDH1), mitochondrial malate dehydrogenase (MDH2), and the partial sequence of aspartate glutamate carrier (AGC) and oxoglutarate malate carrier (OMC) genes were cloned and sequenced; MDH1, MDH2, AGC and OMC mRNA levels were determined by real-time PCR; the specific activities of MDH1 and MDH2 in liver of plateau zokor and plateau pika were measured using enzymatic methods. The results showed that, (1) the ratio of liver weight to body weight, the number and the specific surface of mitochondria in hepatocyte of plateau zokor were markedly higher than those of plateau pika (P 0.05); (3) mRNA level and enzymatic activity of MDH1 was significantly lower than those of MDH2 in the pika liver (P 0.05). These results indicate that the plateau zokor obtains ATP in the enduring digging activity by enhancing the function of MA, while plateau pika gets glycogen for their sprint running activity by increasing the process of gluconeogenesis. As a result, plateau pika converts the lactic acid quickly produced in their skeletal muscle by anaerobic glycolysis and reduces dependence on the oxygen.

  2. Enzymatic Kinetic Properties of the Lactate Dehydrogenase Isoenzyme C4 of the Plateau Pika (Ochotona curzoniae

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    Yang Wang

    2016-01-01

    Full Text Available Testis-specific lactate dehydrogenase (LDH-C4 is one of the lactate dehydrogenase (LDH isozymes that catalyze the terminal reaction of pyruvate to lactate in the glycolytic pathway. LDH-C4 in mammals was previously thought to be expressed only in spermatozoa and testis and not in other tissues. Plateau pika (Ochotona curzoniae belongs to the genus Ochotona of the Ochotonidea family. It is a hypoxia-tolerant species living in remote mountain areas at altitudes of 3000–5000 m above sea level on the Qinghai-Tibet Plateau. Surprisingly, Ldh-c is expressed not only in its testis and sperm, but also in somatic tissues of plateau pika. To shed light on the function of LDH-C4 in somatic cells, Ldh-a, Ldh-b, and Ldh-c of plateau pika were subcloned into bacterial expression vectors. The pure enzymes of Lactate Dehydrogenase A4 (LDH-A4, Lactate Dehydrogenase B4 (LDH-B4, and LDH-C4 were prepared by a series of expression and purification processes, and the three enzymes were identified by the method of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE and native polyacrylamide gel electrophoresis (PAGE. The enzymatic kinetics properties of these enzymes were studied by Lineweaver-Burk double-reciprocal plots. The results showed the Michaelis constant (Km of LDH-C4 for pyruvate and lactate was 0.052 and 4.934 mmol/L, respectively, with an approximate 90 times higher affinity of LDH-C4 for pyruvate than for lactate. At relatively high concentrations of lactate, the inhibition constant (Ki of the LDH isoenzymes varied: LDH-A4 (Ki = 26.900 mmol/L, LDH-B4 (Ki = 23.800 mmol/L, and LDH-C4 (Ki = 65.500 mmol/L. These data suggest that inhibition of lactate by LDH-A4 and LDH-B4 were stronger than LDH-C4. In light of the enzymatic kinetics properties, we suggest that the plateau pika can reduce reliance on oxygen supply and enhance its adaptation to the hypoxic environments due to increased anaerobic glycolysis by LDH-C4.

  3. Enzymatic Kinetic Properties of the Lactate Dehydrogenase Isoenzyme C4 of the Plateau Pika (Ochotona curzoniae)

    Science.gov (United States)

    Wang, Yang; Wei, Lian; Wei, Dengbang; Li, Xiao; Xu, Lina; Wei, Linna

    2016-01-01

    Testis-specific lactate dehydrogenase (LDH-C4) is one of the lactate dehydrogenase (LDH) isozymes that catalyze the terminal reaction of pyruvate to lactate in the glycolytic pathway. LDH-C4 in mammals was previously thought to be expressed only in spermatozoa and testis and not in other tissues. Plateau pika (Ochotona curzoniae) belongs to the genus Ochotona of the Ochotonidea family. It is a hypoxia-tolerant species living in remote mountain areas at altitudes of 3000–5000 m above sea level on the Qinghai-Tibet Plateau. Surprisingly, Ldh-c is expressed not only in its testis and sperm, but also in somatic tissues of plateau pika. To shed light on the function of LDH-C4 in somatic cells, Ldh-a, Ldh-b, and Ldh-c of plateau pika were subcloned into bacterial expression vectors. The pure enzymes of Lactate Dehydrogenase A4 (LDH-A4), Lactate Dehydrogenase B4 (LDH-B4), and LDH-C4 were prepared by a series of expression and purification processes, and the three enzymes were identified by the method of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and native polyacrylamide gel electrophoresis (PAGE). The enzymatic kinetics properties of these enzymes were studied by Lineweaver-Burk double-reciprocal plots. The results showed the Michaelis constant (Km) of LDH-C4 for pyruvate and lactate was 0.052 and 4.934 mmol/L, respectively, with an approximate 90 times higher affinity of LDH-C4 for pyruvate than for lactate. At relatively high concentrations of lactate, the inhibition constant (Ki) of the LDH isoenzymes varied: LDH-A4 (Ki = 26.900 mmol/L), LDH-B4 (Ki = 23.800 mmol/L), and LDH-C4 (Ki = 65.500 mmol/L). These data suggest that inhibition of lactate by LDH-A4 and LDH-B4 were stronger than LDH-C4. In light of the enzymatic kinetics properties, we suggest that the plateau pika can reduce reliance on oxygen supply and enhance its adaptation to the hypoxic environments due to increased anaerobic glycolysis by LDH-C4. PMID:26751442

  4. Bartonella Species Detected in the Plateau Pikas (Ochotona curzoiae) from Qinghai Plateau in China.

    Science.gov (United States)

    Rao, Hua Xiang; Yu, Juan; Guo, Peng; Ma, Yong Cheng; Liu, Qi Yong; Jiao, Ming; Ma, Zhong Wen; Ge, Hua; Wang, Chun Xiang; Song, Xiu Ping; Shi, Yan; Li, Dong Mei

    2015-09-01

    Bartonella species can infect a variety of mammalian hosts and cause a broad spectrum of diseases in humans, but there have been no reports of Bartonella infection in Ochotonidae. This is the first study to detect Bartonella in plateau pikas in the Qinghai plateau, providing baseline data for the risk assessment of human Bartonella infection in this area. We obtained 15 Bartonella strains from 79 pikas in Binggou and Maixiu areas of Qinghai with a positive rate of 18.99%. Based on the phylogenetic analysis of the Bartonella citrate synthase (gltA) gene sequences, most strains were closely related to B. taylorii (3/15) and B. grahamii (12/15). The latter is a pathogenic strain in humans. Our results suggest that a corresponding prevention and control strategy should be taken into consideration in the Qinghai province.

  5. The expression of Ldh-c in the skeletal muscle of plateau pika (Ochotona curzoniae enhances adaptation to a hypoxic environment

    Directory of Open Access Journals (Sweden)

    Zhi F. An

    2017-09-01

    Full Text Available The plateau pika (Ochotona curzoniae is a species of sprint-running alpine animals in the Qinghai-Tibet Plateau, which is a harsh highland hypoxic environment. Ldh-c is expressed in the testis, sperm and somatic tissues of plateau pika. To reveal the role and physiological mechanisms of sperm-specific lactate dehydrogenase (LDH-C4, in plateau pika to adapt to hypoxic environment, an adenoviral line of pMultiRNAi-Ldhc was constructed and injected into the bilateral biceps femoris of the hind legs. The swimming times of the pikas, and the Ldh-c expression levels, total LDH activities and ATP levels in skeletal muscle, were measured after the pikas were raised in the trapped site for 5 days. Our results showed that after Ldh-c was silenced, the sprint-running ability (swimming time of the plateau pikas was significant decreased, and the total LDH activities and ATP levels were reduced by 28.21% and 27.88%, respectively. Our results indicated that expression of Ldh-c in the skeletal muscle of plateau pika increased anaerobic glycolysis and enhanced adaptation to highland hypoxic environments.

  6. Inhibition of inducible nitric oxide synthase expression and nitric oxide production in plateau pika (Ochotona curzoniae) at high altitude on Qinghai-Tibet Plateau.

    Science.gov (United States)

    Xie, Ling; Zhang, Xuze; Qi, Delin; Guo, Xinyi; Pang, Bo; Du, Yurong; Zou, Xiaoyan; Guo, Songchang; Zhao, Xinquan

    2014-04-30

    Nitric oxide (NO), a potent vasodilator, plays an important role in preventing hypoxia induced pulmonary hypertension. Endogenous NO is synthesized by nitric oxide synthases (NOSs) from l-arginine. In mammals, three different NOSs have been identified, including neuronal NOS (nNOS), endothelial NOS (eNOS) and inducible NOS (iNOS). Plateau pika (Ochotona curzoniae) is a typical hypoxia tolerant mammal that lives at 3000-5000 m above sea level on the Qinghai-Tibet Plateau. The aim of this study was to investigate whether NOS expression and NO production are regulated by chronic hypoxia in plateau pika. Quantitative real-time PCR and western blot analyses were conducted to quantify relative abundances of iNOS and eNOS transcripts and proteins in the lung tissues of plateau pikas at different altitudes (4550, 3950 and 3200 m). Plasma NO metabolites, nitrite/nitrate (NO(x)⁻) levels were also examined by Ion chromatography to determine the correlation between NO production and altitude level. The results revealed that iNOS transcript levels were significantly lower in animals at high altitudes (decreased by 53% and 57% at altitude of 3950 and 4550 m compared with that at 3200 m). Similar trends in iNOS protein abundances were observed (26% and 41% at 3950 and 4550 m comparing with at 3200 m). There were no significant differences in eNOS mRNA and protein levels in the pika lungs among different altitudes. The plasma NO(x)⁻ levels of the plateau pikas at high altitudes significantly decreased (1.65±0.19 μg/mL at 3200 m to 0.44±0.03 μg/mL at 3950 m and 0.24±0.01 μg/mL at 4550 m). This is the first evidence describing the effects of chronic hypoxia on NOS expression and NO levels in the plateau pika in high altitude adaptation. We conclude that iNOS expression and NO production are suppressed at high altitudes, and the lower NO concentration at high altitudes may serve crucial roles for helping the plateau pika to survive at hypoxic environment.

  7. [The expression of the sperm-specific lactate dehydrogenase gene Ldh-c in plateau pika (Ochotona curzoniae) cardiac muscle and its effect on the anaerobic glycolysis].

    Science.gov (United States)

    Li, Xiao; Wei, Lian; Wang, Yang; Xu, Li-Na; Wei, Lin-Na; Wei, Deng-Bang

    2015-06-25

    The plateau pika (Ochotona curzoniae) has a strong adaptability to hypoxic plateau environment. We found that the sperm-specific lactate dehydrogenase (LDH-C4) gene Ldh-c expressed in plateau pika cardiac muscle. In order to shed light on the effect of LDH-C4 on the anaerobic glycolysis in plateau pika cardiac muscle, 20 pikas were randomly divided into the inhibitor group and the control group, and the sample size of each group was 10. The pikas of inhibitor group were injected with 1 mL 1 mol/L N-isopropyl oxamate, a specific LDH-C4 inhibitor, in biceps femoris muscle of hind legs, each leg with 500 μL. The pikas of control group were injected with the same volume of normal saline (0.9% NaCl). The mRNA and protein expression levels of Ldh-c gene in plateau pika cardiac muscle were determined by real-time PCR and Western blot. The activities of LDH, and the contents of lactate (LD) and ATP in cardiac muscle were compared between the inhibitor group and the control group. The results showed that 1) the expression levels of Ldh-c mRNA and protein were 0.47 ± 0.06 and 0.68 ± 0.08, respectively; 2) 30 min after injection of 1 mL 1 mol/L N-isopropyl oxamate in biceps femoris muscle, the concentration of N-isopropyl oxamate in blood was 0.08 mmol/L; 3) in cardiac muscle of the inhibitor group and the control group, the LDH activities were (6.18 ± 0.48) U/mg and (9.08 ± 0.58) U/mg, the contents of LD were (0.21 ± 0.03) mmol/g and (0.26 ± 0.04) mmol/g, and the contents of ATP were (4.40 ± 0.69) nmol/mg and (6.18 ± 0.73) nmol/mg (P < 0.01); 5) the inhibition rates of N-isopropyl oxamate to LDH, LD and ATP were 31.98%, 20.90% and 28.70%, respectively. The results suggest that Ldh-c expresses in cardiac muscle of plateau pika, and the pika cardiac muscle may get at least 28% ATP for its activities by LDH-C4 catalyzed anaerobic glycolysis, which reduces the dependence on oxygen and enhances the adaptation to the hypoxic environments.

  8. Plastic pikas: Behavioural flexibility in low-elevation pikas (Ochotona princeps)

    Science.gov (United States)

    Varner, Johanna; Horns, Joshua J.; Lambert, Mallory S.; Westberg, Elizabeth; Ruff, James; Wolfenberger, Katelyn; Beever, Erik; Dearing, M. Denise

    2016-01-01

    Behaviour is an important mechanism for accommodating rapid environmental changes. Understanding a species’ capacity for behavioural plasticity is therefore a key, but understudied, aspect of developing tractable conservation and management plans under climate-change scenarios. Here, we quantified behavioural differences between American pikas (Ochotona princeps) living in an atypical, low-elevation habitat versus those living in a more-typical, alpine habitat. With respect to foraging strategy, low-elevation pikas spent more time consuming vegetation and less time caching food for winter, compared to high-elevation pikas. Low-elevation pikas were also far more likely to be detected in forested microhabitats off the talus than their high-elevation counterparts at midday. Finally, pikas living in the atypical habitat had smaller home range sizes compared to those in typical habitat or any previously published home ranges for this species. Our findings indicate that behavioural plasticity likely allows pikas to accommodate atypical conditions in this low-elevation habitat, and that they may rely on critical habitat factors such as suitable microclimate refugia to behaviourally thermoregulate. Together, these results suggest that behavioural adjustments are one important mechanism by which pikas can persist outside of their previously appreciated dietary and thermal niches.

  9. Abrupt motion tracking of plateau pika (Ochotona curzoniae) based on local texture and color model%基于纹理颜色模型的高原鼠兔突变运动跟踪

    Institute of Scientific and Technical Information of China (English)

    陈海燕; 张爱华; 胡世亚

    2016-01-01

    针对自然生境环境下高原鼠兔跟踪中,鼠兔毛色呈保护色与背景颜色相近以及运动随机的问题,构造了一种局部纹理差异性算子LTDC(local ternary difference count),来表征目标和背景之间的细微差异性,弥补了采用单一LTC(local ternary count)算子的不足。通过运动信息来判断鼠兔的运动模式,不同的模式采用不同的采样跟踪策略。把所构造的LTDC算子与R(red)G(green)B(blue)颜色信息相结合来表示目标,并把该目标表示模型引入到运动信息引导的高原鼠兔跟踪方法中。通过对采集的秋冬季节高原鼠兔视频图像进行测试,分析跟踪的成功率和误差,得到的 LTDC 纹理颜色模型的目标表示方法在鼠兔发生突变运动时,由于采用了运动信息引导的采样跟踪方式,能够有效地捕获突变目标,跟踪成功率达到97.93%。在鼠兔发生平滑运动时,尽管目标与背景颜色相近,依然能够稳定地跟踪目标,跟踪误差较小,误差波动范围也较小,误差均值为19.56,误差方差为74.24。试验结果表明:所提出的跟踪方法具有较强的目标与背景区分能力,在目标和背景颜色相近、运动复杂的场景中,能够较为准确地实现高原鼠兔目标的定位。%Plateau pika(Ochotona curzoniae) is one of the main biological disasters in the Qinghai-Tibet plateau and adjacent areas in China. Video-based animal behavior analysis is a critical and fascinating problem for both biologists and computer vision scientists. According to the color similarity betweenPlateau pika and the background, as well as the uncertainty and randomness of plateau pika motion in natural habitat environment, a new visual descriptor named the local texture difference operator LTDC was proposed to reflect the subtle differences between the plateau pika and the background. The LTDC operator, being more robust to target expression

  10. The Interaction Between Plateau pikas (Ochotona curzoniae) and White rumpped snow-finches(Pyrilauda taczanowskii)at Nian village , Rutog Township of Medrolgongkar County%西藏拉萨市墨竹工卡县日多镇念村高原鼠兔与白腰雪雀的生态关系探讨

    Institute of Scientific and Technical Information of China (English)

    米玛旺堆; 次旦吉美

    2015-01-01

    Study on the interaction between plateau pikas (Ochotona curzoniae) and white rumpped snow-finches (Pyrilauda taczanowskii)was carried out from the 17th to 14th of Jan in 2014 at Nian village, Rutog Township of Medrolgongkar County. The results showed that there was a significant positive correlation between the numbers of burrow of plateau pikas and white rumpped snow-finches numbers. The mutualism or commensalism between plateau pikas and wite rummped snow finches was indicated. Yet this needs to be further fested based on both observational and experimental studies.%2014年1月7日至14日在西藏拉萨市墨竹工卡县日多镇念村,以牦牛白天取食和夜宿地作为采样点,对高原鼠兔(Ochotona curzoniae)和白腰雪雀(Pyrilauda taczanowskii)的生态关系进行分析.研究者分别对高原鼠兔、白腰雪雀的数目及高原鼠兔的洞穴数目进行统计,并分析了高原鼠兔与白腰雪雀之间的生态关系.研究结果表明,高原鼠兔与白腰雪雀在数量上存在正相关.

  11. 高原鼠兔繁殖期攻击行为的动态格局%Variation in aggressive behavior of plateau pikas (Ochotona curzoniae) during different breeding seasons

    Institute of Scientific and Technical Information of China (English)

    陈千权; 曲家鹏; 张堰铭

    2013-01-01

    为探讨高原鼠兔繁殖期攻击行为强度的变化、检验进化博弈理论有关预测,本研究于2009年5~8月采用标志重捕和中立竞技场法测定了高原鼠兔自然种群斗殴及进攻等行为的发生频率及持续时间.结果表明:5月下旬及6月上旬高原鼠兔雄性斗殴行为发生频率及持续时间显著高于7月下旬和8月中旬;而雌性差异不显著.5月下旬和6月上旬,高原鼠兔雄性个体间的斗殴行为发生频率及持续时间显著高于雌性,其余时期两性间无显著差异.进攻发起者通常是该次殴斗的获胜者;自繁殖高峰期至末期,种群中雄性高原鼠兔鹰对策者比例逐渐下降,与进化博弈论的预测一致.%In order to explore the variation of aggressive level in a plateau pika (Ochotona curzoniae) population during different breeding seasons and test the predictions of evolutionary game theory,the methods of mark recapture and neutral arena were used to measure the frequencies and durations of fight behaviors of plateau pikas in the wild from May to August 2009.Frequencies and durations of fight behaviors between males from later May to early June were significantly higher than those from later July to middle August,while no significant differences of these two parameters between female were detected during the whole study period.Frequencies and durations of fight behaviors between males were significantly higher than those between females from later May to early June,while no significant differences of these two parameters between sexes were detected among other periods.The initiator of a fight was always the winner.Aggressor proportions in the population declined after the peak of reproductive cycle,which coincided with the predictions of evolutionary game theory.

  12. Effect of Hypoxia on Ldh-c Expression in Somatic Cells of Plateau Pika

    OpenAIRE

    Wei, Dengbang; Wei, Linna; Li, Xiao; Wang, Yang; Wei, Lian

    2016-01-01

    Sperm specific lactate dehydrogenases (LDH-C4) is a lactate dehydrogenase that catalyzes the conversion of pyruvate to lactate. In mammals, Ldh-c was originally thought to be expressed only in testes and spermatozoa. Plateau pika (Ochotona curzoniae), which belongs to the genus Ochotona of the Ochotonidea family, is a hypoxia-tolerant mammal living 3000–5000 m above sea level on the Qinghai-Tibet Plateau, an environment which is strongly hypoxic. Ldh-c is expressed not only in testes and sper...

  13. Functional difference of malate-aspartate shuttle system in liver between plateau zokor (Myospalax baileyi) and plateau pika (Ochotona curzoniae)%高原鼢鼠和高原鼠兔肝脏苹果酸天冬氨酸穿梭系统的功能差异

    Institute of Scientific and Technical Information of China (English)

    朱瑞娟; 饶鑫峰; 魏登邦; 王多伟; 魏莲; 孙生祯

    2012-01-01

    To explore the adaptive mechanisms of plateau zokor (Myospalax baileyi) to the enduring digging activity in the hypoxic environment and of plateau pika (Ochotona curzoniae) to the sprint running activity, the functional differences of malate-aspartate shuttle system (MA) in liver of plateau zokor and plateau pika were studied. The ratio of liver weight to body weight, the parameters of mitochondria in hepatocyte and the contents of lactic acid in serum were measured; the open reading frame of cytoplasmic malate dehydrogenase (MDH1), mitochondrial malate dehydrogenase (MDH2), and the partial sequence of aspartate glutamate carrier (AGC) and oxoglutarate malate carrier (OMC) genes were cloned and sequenced; MDH1, MDH2, AGC and OMC mRNA levels were determined by real-time PCR; the specific activities of MDHI and MDH2 in liver of plateau zokor and plateau pika were measured using enzymatic methods. The results showed that, (1) the ratio of liver weight to body weight, the number and the specific surface of mitochondria in hepatocyte of plateau zokor were markedly higher than those of plateau pika (P 0.05); (3) mRNA level and enzymatic activity of MDHl was significantly lower than those of MDH2 in the pika liver (P 0.05). These results indicate that the plateau zokor obtains ATP in the enduring digging activity by enhancing the function of MA, while plateau pika gets glycogen for their sprint running activity by increasing the process of gluconeogenesis. As a result, plateau pika converts the lactic acid quickly produced in their skeletal muscle by anaerobic glycolysis and reduces dependence on the oxygen.%为了探讨高原鼢鼠(Myospalax baileyi)和高原鼠兔(Ochotona curzoniae)在低氧环境下适应耐力性挖掘活动和快速奔跑的生理机制,本文比较研究了这两种高原动物肝脏中苹果酸天冬氨酸穿梭系统(malate-spartate shuttle system,MA)的功能差异.测定高原鼢鼠和高原鼠兔的肝脏体重比、肝细胞中线粒体参

  14. Effect of Hypoxia on Ldh-c Expression in Somatic Cells of Plateau Pika.

    Science.gov (United States)

    Wei, Dengbang; Wei, Linna; Li, Xiao; Wang, Yang; Wei, Lian

    2016-08-01

    Sperm specific lactate dehydrogenases (LDH-C₄) is a lactate dehydrogenase that catalyzes the conversion of pyruvate to lactate. In mammals, Ldh-c was originally thought to be expressed only in testes and spermatozoa. Plateau pika (Ochotona curzoniae), which belongs to the genus Ochotona of the Ochotonidea family, is a hypoxia-tolerant mammal living 3000-5000 m above sea level on the Qinghai-Tibet Plateau, an environment which is strongly hypoxic. Ldh-c is expressed not only in testes and sperm, but also in the somatic tissues of plateau pika. To reveal the effect of hypoxia on pika Ldh-c expression, we investigated the mRNA and protein level of Ldh-c as well as the biochemical index of anaerobic glycolysis in pika somatic tissues at the altitudes of 2200 m, 3200 m and 3900 m. Our results showed that mRNA and protein expression levels of Ldh-c in the tissues of pika's heart, liver, brain and skeletal muscle were increased significantly from 2200 m to 3200 m, but had no difference from 3200 m to 3900 m; the activities of LDH and the contents of lactate showed no difference from 2200 m to 3200 m, but were increased significantly from 3200 m to 3900 m. Hypoxia up-regulated and maintained the expression levels of Ldh-c in the pika somatic cells. Under the hypoxia condition, plateau pikas increased anaerobic glycolysis in somatic cells by LDH-C₄, and that may have reduced their dependence on oxygen and enhanced their adaptation to the hypoxic environment.

  15. Phylogenetic relationships of five pika species (genus Ochotona) based on mitochondrial DNA restriction maps

    Institute of Scientific and Technical Information of China (English)

    于宁; 郑昌琳; 施立明; 王文; 兰宏; 张亚平

    1996-01-01

    Restriction site mapping of mitochondrial DNA (mtDNA) with 16 restriction endonucleases was used to examine the phylogenetic relationships of Ochotona cansus, O. huangensis, O. thibetana, O. curzoniae and O. erythrotis. A 1-kb length variation between 0. erythrotis of subgenus Pika and other four species of subgenus Ochotona was observed, which may be a useful genetic marker for identifying the two subgenera. The phylogenetic tree constructed using PAUP based on 61 phylogenetically informative sites suggests that O. aythrotis diverged first, followed by O. cansus, while O. atrzoniae and O. huangensis are sister taxa related to O. thibetana. The results indicate that both O. cansus and O. huangensis should be treated as independent species. If the base substitution rate of pikas mtDNA was 2% per million years, then the divergence time of the two subgenera, Pika and Ochotona, is about 8.8 Ma ago of late Miocence, middle Bao-dian of Chinese mammalian age, and the divergence of the four species in subgenus

  16. The burying and grazing effects of plateau pika on alpine grassland are small: a pilot study in a semiarid basin on the Qinghai-Tibet Plateau

    Science.gov (United States)

    Yi, Shuhua; Chen, Jianjun; Qin, Yu; Xu, Gaowei

    2016-11-01

    There is considerable controversy about the effects of plateau pika (Ochotona curzoniae, hereafter pika) on alpine grassland on the Qinghai-Tibet Plateau (QTP). On the one hand, pika is considered a keystone species. On the other hand, it is being poisoned. Although significant efforts have been made to study the effects of pika at a quadrat scale ( ˜ m2), our knowledge about its distribution and effects at a larger scale is very limited. In this study, we investigated the direct effects, i.e., burying and grazing, of pika by upscaling field sampling at a quadrat scale to a plot scale ( ˜ 1000 m2) by aerial photographing. Altogether 168 plots were set on four different types of alpine grassland in a semiarid basin on the QTP. Results showed that (1) the effects of pika pile burying on the reduction of vegetation cover, biomass, soil carbon, and nitrogen were less than 10 %, which was much smaller than the effects of bald patches; and (2) pika consumed 8-21 % of annual net primary production of grassland. We concluded that the direct burying and grazing effects of pika on alpine grassland were minor in this region. The quadcopter is an efficient and economic tool for long-term repeated monitoring over large regions for further understanding the role of pika.

  17. Facing a changing world: Thermal physiology of American pikas (Ochotona princeps)

    Science.gov (United States)

    Otto, Hans W; Wilson, James A; Beever, Erik

    2015-01-01

    American pikas (Ochotona princeps) are of concern with respect to warming montane temperatures; however, little information exists regarding their physiological ability to adapt to warming temperatures. Previous studies have shown that pikas have high metabolism and low thermal conductance, which allow survival during cold winters. It has been hypothesized that these characteristics may be detrimental, given the recent warming trends observed in montane ecosystems. We examined resting metabolic rate, surface activity, and den and ambient temperatures (Ta) of pikas in late summer (August 2011 and 2012) at 2 locations in the Rocky Mountains. Resting metabolic rate was calculated to be 2.02 mL O2 · g-1h-1, with a lower critical temperature (LCT) of 28.1 ± 0.2 °C. No upper critical temperature (UCT) could be determined from our data; therefore, the estimated thermoneutral zone (TNZ) was 28.1 °C to at least 35.0 °C (upper experimental temperature). Pikas in this study showed the same bimodal above-talus activity patterns reported in previous studies. Den temperatures in Colorado were correlated with, but consistently lower than, current ambient temperatures. Wyoming den temperatures showed a weak correlation with Ta 20 min prior to the current den temperature. This study is one of few to present data on the physiological response pikas may have to current warming conditions, and the first to perform metabolic measurements in situ. Our data support conclusions of previous studies, specifically MacArthur and Wang (1973, 1974) and Smith (1974), which indicated American pikas may not have the physiological ability to cope with high Ta. Our results also highlight the importance of shaded regions below the talus rocks for behavioral thermoregulation by pikas.

  18. Efficacies of coccidian parasites (Protozoa) in control of plateau pika (Ochotona curzoniae) and their effects on embryo development%艾美尔球虫防治高原鼠兔实验及对其胚胎发育的影响

    Institute of Scientific and Technical Information of China (English)

    杜寅; 曹伊凡; 景增春; 何慧; 边疆晖

    2012-01-01

    The plateau pika (Ochotona curzoniae) has been recorded as one of the serious pests in alpine meadows on the Qinghai-Tibet Plateau. However, biological control, recognized as a primary way in pest control, generally does not display visible effectiveness in the short term. Coccidian parasites are intestinal protozoans, and are currently recognized as the main parasite infecting plateau pika populations. Infection with coccidia seriously impairs the survival of hosts. In order to test whether coccidia could be used for control pikas, we incorporated coccidia into bait and tested its efficacies in both laboratory and field. Our results showed that the bait ( containing 300 × 10 oocysts and synergist) led 63. 6% adults to die in the laboratory, and 54.9% and 71.0% decreases in numbers of adults and juveniles in field, respectively. In addition, embryo weight was significant lower in the treatment group than that in the control group. Infection rate and infection intensity were significantly higher in treatment plots than those in control plots. Our results suggest that coccidian parasites have good effectiveness in pika control, and it may also influence embryo development of pregnant female infected in the field.%高原鼠兔是青藏高原地区危害高寒草甸植被的主要有害小哺乳动物.生物控制为有害动物防治的主要发展方向,但存在防治效果见效慢的缺点.艾美尔球虫是高原鼠兔肠道内的主要寄生物,并对宿主具有专一性寄生的特点.为将艾美尔球虫研发成新型的高原鼠兔无公害生物防治制剂,本文测定了球虫毒饵对高原鼠兔致死率并在野外进行了灭鼠实验.结果表明,添加增效剂的300万球虫毒饵在室内可导致63.6%的成年个体死亡,在野外可导致54.9%成体和71.0%幼体死亡.灭鼠后残存高原鼠兔的球虫感染率和感染强度显著大于对照个体,且妊娠雌体的胚胎重较对照显著降低.上述结果说明,艾美尔球虫

  19. Alpine biodiversity and assisted migration: The case of the American pika (Ochotona princeps)

    Science.gov (United States)

    Wilkening, Jennifer L.; Ray, Chris; Ramsay, Nathan G.; Klingler, Kelly

    2015-01-01

    Alpine mammals are predicted to be among the species most threatened by climate change, due to the projected loss and further fragmentation of alpine habitats. As temperature or precipitation regimes change, alpine mammals may also be faced with insurmountable barriers to dispersal. The slow rate or inability to adjust to rapidly shifting environmental conditions may cause isolated alpine species to become locally extirpated, resulting in reduced biodiversity. One proposed method for mitigating the impacts of alpine species loss is assisted migration. This method, which involves translocating a species to an area with more favourable climate and habitat characteristics, has become the subject of debate and controversy in the conservation community. The uncertainty associated with climate change projections, coupled with the thermal sensitivity of many alpine mammals, makes it difficult to a priori assess the efficacy of this technique as a conservation management tool. Here we present the American pika (Ochotona princeps) as a case study. American pikas inhabit rocky areas throughout the western US, and populations in some mountainous areas have become locally extirpated in recent years. We review known climatic and habitat requirements for this species, and also propose protocols designed to reliably identify favourable relocation areas. We present data related to the physiological constraints of this species and outline specific requirements which must be addressed for translocation of viable populations, including wildlife disease and genetic considerations. Finally, we discuss potential impacts on other alpine species and alpine communities, and overall implications for conserving alpine biodiversity in a changing climate.

  20. Predictors of current and longer-term patterns of abundance of American pikas (Ochotona princeps) across a leading-edge protected area

    Science.gov (United States)

    Moyer-Horner, Lucas; Beever, Erik A.; Johnson, Douglas H.; Beil, Mark; Belt, Jami

    2016-01-01

    American pikas (Ochotona princeps) have been heralded as indicators of montane-mammal response to contemporary climate change. Pikas no longer occupy the driest and lowest-elevation sites in numerous parts of their geographic range. Conversely, pikas have exhibited higher rates of occupancy and persistence in Rocky Mountain and Sierra Nevada montane ‘mainlands’. Research and monitoring efforts on pikas across the western USA have collectively shown the nuance and complexity with which climate will often act on species in diverse topographic and climatic contexts. However, to date no studies have investigated habitat, distribution, and abundance of pikas across hundreds of sites within a remote wilderness area. Additionally, relatively little is known about whether climate acts most strongly on pikas through direct or indirect (e.g., vegetation-mediated) mechanisms. During 2007–2009, we collectively hiked >16,000 km throughout the 410,077-ha Glacier National Park, Montana, USA, in an effort to identify topographic, microrefugial, and vegetative characteristics predictive of pika abundance. We identified 411 apparently pika-suitable habitat patches with binoculars (in situ), and surveyed 314 of them for pika signs. Ranking of alternative logistic-regression models based on AICc scores revealed that short-term pika abundances were positively associated with intermediate elevations, greater cover of mosses, and taller forbs, and decreased each year, for a total decline of 68% during the three-year study; whereas longer-term abundances were associated only with static variables (longitude, elevation, gradient) and were lower on north-facing slopes. Earlier Julian date and time of day of the survey (i.e., midday vs. not) were associated with lower observed pika abundance. We recommend that wildlife monitoring account for this seasonal and diel variation when surveying pikas. Broad-scale information on status and abundance determinants of montane mammals, especially

  1. Herbivory and Competition of Tibetan Steppe Vegetation in Winter Pasture: Effects of Livestock Exclosure and Plateau Pika Reduction.

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    Richard B Harris

    Full Text Available Rangeland degradation has been identified as a serious concern in alpine regions of western China on the Qinghai-Tibetan plateau (QTP. Numerous government-sponsored programs have been initiated, including many that feature long-term grazing prohibitions and some that call for eliminating pastoralism altogether. As well, government programs have long favored eliminating plateau pikas (Ochotona curzoniae, assumed to contribute to degraded conditions. However, vegetation on the QTP evolved in the presence of herbivory, suggesting that deleterious effects from grazing are, to some extent, compensated for by reduced plant-plant competition. We examined the dynamics of common steppe ecosystem species as well as physical indicators of rangeland stress by excluding livestock and reducing pika abundance on experimental plots, and following responses for 4 years. We established 12 fenced livestock exclosures within pastures grazed during winter by local pastoralists, and removed pikas on half of these. We established paired, permanent vegetation plots within and outside exclosures and measured indices of erosion and biomass of common plant species. We observed modest restoration of physical site conditions (reduced bare soil, erosion, greater vegetation cover with both livestock exclusion and pika reduction. As expected in areas protected from grazing, we observed a reduction in annual productivity of plant species avoided by livestock and assumed to compete poorly when protected from grazing. Contrary to expectation, we observed similar reductions in annual productivity among palatable, perennial graminoids under livestock exclusion. The dominant grass, Stipa purpurea, displayed evidence of density-dependent growth, suggesting that intra-specific competition exerted a regulatory effect on annual production in the absence of grazing. Complete grazing bans on winter pastures in steppe habitats on the QTP may assist in the recovery of highly eroded pastures

  2. Why museums matter: a tale of pinworms (Oxyuroidea: Heteroxynematidae) among pikas (Ochotona princeps and O. collaris) in the American west.

    Science.gov (United States)

    Hoberg, E P; Pilitt, P A; Galbreath, K E

    2009-04-01

    Permanent and well-supported museum or natural history collections provide a solid foundation for the process of systematics research through creation of an empirical record which validates our understanding of the biosphere. We explore the role of museums in ongoing studies of the complex helminth fauna characteristic of pikas (Ochotona spp.) in the American west. These studies address the taxonomy for pinworms of the Labiostomatinae and the problems associated with the absence of adequate type series and vouchers and with misidentifications in original descriptions. We demonstrate that the types for Labiostomum (Labiostomum) coloradensis are identical to some specimens in the syntype series representing L. (Eugenuris) utahensis, although the published descriptions are in disagreement. Both are identical to L. (Eugenuris) talkeetnaeuris and, as a consequence, are reduced as junior synonyms. Only 2 species of large pinworms, namely L. (Labiostomum) rauschi and L. (Eugenuris) talkeetnaeuris, are widely distributed in Ochotona collaris and O. princeps. Although this serves to clarify the taxonomy for species in these genera, prior records remain confused, as representative voucher specimens from all major surveys in North America were never submitted to museum collections. We strongly suggest that type and voucher series should not be held in private or personal collections, where such are eventually lost, discarded, or destroyed through neglect due to inattention and the absence of curation. The potential to accumulate meaningful baselines for assessment of environmental change is jeopardized if materials from survey and inventory are not routinely submitted to museum collections. The capacity of museum repositories, as a focus for systematics, ecology, and evolutionary studies and for the development of resources for biodiversity informatics, continues to be undervalued and poorly utilized by a cadre of scientists who are dependant on accurate and definitive

  3. Climate Tolerances and Habitat Requirements Jointly Shape the Elevational Distribution of the American Pika (Ochotona princeps), with Implications for Climate Change Effects.

    Science.gov (United States)

    Yandow, Leah H; Chalfoun, Anna D; Doak, Daniel F

    2015-01-01

    Some of the most compelling examples of ecological responses to climate change are elevational range shifts of individual species, which have been observed throughout the world. A growing body of evidence, however, suggests substantial mediation of simple range shifts due to climate change by other limiting factors. Understanding limiting factors for a species within different contexts, therefore, is critical for predicting responses to climate change. The American pika (Ochotona princeps) is an ideal species for investigating distributions in relation to climate because of their unusual and well-understood natural history as well as observed shifts to higher elevation in parts of their range. We tested three hypotheses for the climatic or habitat characteristics that may limit pika presence and abundance: summer heat, winter snowpack, and forage availability. We performed these tests using an index of pika abundance gathered in a region where environmental influences on pika distribution have not been well-characterized. We estimated relative pika abundance via scat surveys and quantified climatic and habitat characteristics across two North-Central Rocky Mountain Ranges, the Wind River and Bighorn ranges in Wyoming, USA. Pika scat density was highest at mid-elevations and increased linearly with forage availability in both ranges. Scat density also increased with temperatures conducive to forage plant growth, and showed a unimodal relationship with the number of days below -5°C, which is modulated by insulating snowpack. Our results provide support for both the forage availability and winter snowpack hypotheses. Especially in montane systems, considering the context-dependent nature of climate effects across regions and elevations as well as interactions between climatic and other critical habitat characteristics, will be essential for predicting future species distributions.

  4. Climate Tolerances and Habitat Requirements Jointly Shape the Elevational Distribution of the American Pika (Ochotona princeps, with Implications for Climate Change Effects.

    Directory of Open Access Journals (Sweden)

    Leah H Yandow

    Full Text Available Some of the most compelling examples of ecological responses to climate change are elevational range shifts of individual species, which have been observed throughout the world. A growing body of evidence, however, suggests substantial mediation of simple range shifts due to climate change by other limiting factors. Understanding limiting factors for a species within different contexts, therefore, is critical for predicting responses to climate change. The American pika (Ochotona princeps is an ideal species for investigating distributions in relation to climate because of their unusual and well-understood natural history as well as observed shifts to higher elevation in parts of their range. We tested three hypotheses for the climatic or habitat characteristics that may limit pika presence and abundance: summer heat, winter snowpack, and forage availability. We performed these tests using an index of pika abundance gathered in a region where environmental influences on pika distribution have not been well-characterized. We estimated relative pika abundance via scat surveys and quantified climatic and habitat characteristics across two North-Central Rocky Mountain Ranges, the Wind River and Bighorn ranges in Wyoming, USA. Pika scat density was highest at mid-elevations and increased linearly with forage availability in both ranges. Scat density also increased with temperatures conducive to forage plant growth, and showed a unimodal relationship with the number of days below -5°C, which is modulated by insulating snowpack. Our results provide support for both the forage availability and winter snowpack hypotheses. Especially in montane systems, considering the context-dependent nature of climate effects across regions and elevations as well as interactions between climatic and other critical habitat characteristics, will be essential for predicting future species distributions.

  5. Relationships of Periglacial Processes to Habitat Quality and Thermal Environment of Pikas (Lagomorpha, Ochotona) in Alpine and High-Latitude Environments (Invited)

    Science.gov (United States)

    Millar, C. I.; Smith, A. T.; Hik, D. S.

    2009-12-01

    Patterned-ground and related periglacial features such as rock-glaciers and fractured-rock talus are emblematic of cold and dry arctic environments. The freeze-thaw processes that cause these features were first systematically investigated in the pioneering work of Linc Washburn. Unusual internal and autonomous micro-climatic and hydrologic processes of these features, however, are only beginning to be understood. Such features occur also in temperate latitude mountains, often in surprising abundance in regions such as the Great Basin (NV, USA) and San Juan Mtns (CO, USA), where they occur as active as well as relict (neoglacial or Pleistocene) features. Rock-dwelling species of pikas (Ochotona) in temperate North American and Asian mountains and in North American high-latitudes have long been known for their preference for talus habitats. We are investigating geomorphic, climatic, and hydrologic attributes of these periglacial features for their role in habitat quality and thermal environment of pikas. PRISM-modeled and observed climatic conditions from a range of talus types for Ochotona princeps in California and the western Great Basin (USA) indicate that, 1) thermal conditions of intra-talus-matrix in summer are significantly colder than talus-surface temperatures and colder than adjacent slopes and forefield wetlands where pika forage; 2) near-talus-surface locations (where haypiles are situated) are warmer in winter than intra-talus-matrix temperatures; 3) high-quality wetland vegetation in talus forefields is promoted by year-round persistence of outlet springs, seeps, and streams characteristic of active taluses. The importance of snowpack to winter thermal conditions is highlighted from these observations, suggesting a greater sensitivity of habitat in dry temperate regions such as eastern California and Nevada USA to warming winter minimum temperatures than in regions or elevations where snowpacks are more persistent. In regions where warming air

  6. Pika (Ochotona princeps) losses from two isolated regions reflect temperature and water balance, but reflect habitat area in a mainland region

    Science.gov (United States)

    Beever, Erik A.; Perrine, John D.; Rickman, Tom; Flores, Mary; Clark, John P.; Waters, Cassie; Weber, Shana S.; Yardley, Braden; Thoma, David P.; Chesley-Preston, Tara; Goehring, Kenneth E.; Magnuson, Michael; Nordensten, Nancy; Nelson, Melissa; Collins, Gail H.

    2016-01-01

    Although biotic responses to contemporary climate change are spatially pervasive and often reflect synergies between climate and other ecological disturbances, the relative importance of climatic factors versus habitat extent for species persistence remains poorly understood. To address this shortcoming, we performed surveys for American pikas (Ochotona princeps) at > 910 locations in 3 geographic regions of western North America during 2014 and 2015, complementing earlier modern (1994–2013) and historical (1898–1990) surveys. We sought to compare extirpation rates and the relative importance of climatic factors versus habitat area for pikas in a mainland-versus-islands framework. In each region, we found widespread evidence of distributional loss—local extirpations, upslope retractions, and encounter of only old sign. Locally comprehensive surveys suggest extirpation of O. princeps from 5 of 9 new sites from the hydrographic Great Basin and from 11 of 29 sites in northeastern California. Although American pikas were recorded as recently as 2011 in Zion National Park and in 2012 from Cedar Breaks National Monument in Utah, O. princeps now appears extirpated from all reported localities in both park units. Multiple logistic regressions for each region suggested that both temperature-related and water-balance-related variables estimated from DAYMET strongly explained pika persistence at sites in the Great Basin and in Utah but not in the Sierra-Cascade “mainland” portion of northeastern California. Conversely, talus-habitat area did not predict American pika persistence in the Great Basin or Utah but strongly predicted persistence in the Sierra-Cascade mainland. These results not only add new areas to our understanding of long-term trend of the American pika’s distribution, but also can inform decisions regarding allocation of conservation effort and management actions. Burgeoning research on species such as O. princeps has collectively demonstrated the

  7. Adaptive functional evolution of leptin in cold-adaptive pika family

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Aresearch team led by Prof.ZHAO Xinquan with the CAS Northwest Institute of Plateau Biology has put forward the viewpoint for the first time that adaptive functional evolution may occur in the leptin protein of the pika (Ochotona) family, a typical coldadaptive mammal.

  8. Functional evolution of leptin of Ochotona curzoniae in adaptive thermogenesis driven by cold environmental stress.

    Directory of Open Access Journals (Sweden)

    Jie Yang

    Full Text Available BACKGROUND: Environmental stress can accelerate the directional selection and evolutionary rate of specific stress-response proteins to bring about new or altered functions, enhancing an organism's fitness to challenging environments. Plateau pika (Ochotona curzoniae, an endemic and keystone species on Qinghai-Tibetan Plateau, is a high hypoxia and low temperature tolerant mammal with high resting metabolic rate and non-shivering thermogenesis to cope in this harsh plateau environment. Leptin is a key hormone related to how these animals regulate energy homeostasis. Previous molecular evolutionary analysis helped to generate the hypothesis that adaptive evolution of plateau pika leptin may be driven by cold stress. METHODOLOGY/PRINCIPAL FINDINGS: To test the hypothesis, recombinant pika leptin was first purified. The thermogenic characteristics of C57BL/6J mice injected with pika leptin under warm (23±1°C and cold (5±1°C acclimation is investigated. Expression levels of genes regulating adaptive thermogenesis in brown adipose tissue and the hypothalamus are compared between pika leptin and human leptin treatment, suggesting that pika leptin has adaptively and functionally evolved. Our results show that pika leptin regulates energy homeostasis via reduced food intake and increased energy expenditure under both warm and cold conditions. Compared with human leptin, pika leptin demonstrates a superior induced capacity for adaptive thermogenesis, which is reflected in a more enhanced β-oxidation, mitochondrial biogenesis and heat production. Moreover, leptin treatment combined with cold stimulation has a significant synergistic effect on adaptive thermogenesis, more so than is observed with a single cold exposure or single leptin treatment. CONCLUSIONS/SIGNIFICANCE: These findings support the hypothesis that cold stress has driven the functional evolution of plateau pika leptin as an ecological adaptation to the Qinghai-Tibetan Plateau.

  9. Functional Evolution of Leptin of Ochotona curzoniae in Adaptive Thermogenesis Driven by Cold Environmental Stress

    Science.gov (United States)

    Yang, Jie; Bromage, Timothy G.; Zhao, Qian; Xu, Bao Hong; Gao, Wei Li; Tian, Hui Fang; Tang, Hui Jun; Liu, Dian Wu; Zhao, Xin Quan

    2011-01-01

    Background Environmental stress can accelerate the directional selection and evolutionary rate of specific stress-response proteins to bring about new or altered functions, enhancing an organism's fitness to challenging environments. Plateau pika (Ochotona curzoniae), an endemic and keystone species on Qinghai-Tibetan Plateau, is a high hypoxia and low temperature tolerant mammal with high resting metabolic rate and non-shivering thermogenesis to cope in this harsh plateau environment. Leptin is a key hormone related to how these animals regulate energy homeostasis. Previous molecular evolutionary analysis helped to generate the hypothesis that adaptive evolution of plateau pika leptin may be driven by cold stress. Methodology/Principal Findings To test the hypothesis, recombinant pika leptin was first purified. The thermogenic characteristics of C57BL/6J mice injected with pika leptin under warm (23±1°C) and cold (5±1°C) acclimation is investigated. Expression levels of genes regulating adaptive thermogenesis in brown adipose tissue and the hypothalamus are compared between pika leptin and human leptin treatment, suggesting that pika leptin has adaptively and functionally evolved. Our results show that pika leptin regulates energy homeostasis via reduced food intake and increased energy expenditure under both warm and cold conditions. Compared with human leptin, pika leptin demonstrates a superior induced capacity for adaptive thermogenesis, which is reflected in a more enhanced β-oxidation, mitochondrial biogenesis and heat production. Moreover, leptin treatment combined with cold stimulation has a significant synergistic effect on adaptive thermogenesis, more so than is observed with a single cold exposure or single leptin treatment. Conclusions/Significance These findings support the hypothesis that cold stress has driven the functional evolution of plateau pika leptin as an ecological adaptation to the Qinghai-Tibetan Plateau. PMID:21698227

  10. Dynamical Analysis of a Plateau Pika with Cross-Diffusion under Contraception Control

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    Xiaoyan Wang

    2014-01-01

    Full Text Available A plateau pika model with spatial cross-diffusion is investigated. By analyzing the corresponding characteristic equations, the local stability of an coexistence steady state is discussed when d21 is small enough. However, when d21 is large enough, the model shows Turing bifurcation if B2 -4AC > 0. Furthermore, it is proved that if, R > R0, βK > d and cross-diffusion rates are zero, the positive coexistence steady state is globally asymptotically stable. A nonconstant positive solution bifurcates from the coexistent steady state by the Leray-Schauder degree theory. Numerical simulations are carried out to illustrate the main results.

  11. Testis-specific lactate dehydrogenase is expressed in somatic tissues of plateau pikas☆

    Science.gov (United States)

    Wang, Duowei; Wei, Lian; Wei, Dengbang; Rao, Xinfeng; Qi, Xinzhang; Wang, Xiaojun; Ma, Benyuan

    2013-01-01

    LDH-C4 is a lactate dehydrogenase that catalyzes the interconversion of pyruvate with lactate. In mammals the, Ldh-c gene was originally thought to be expressed only in testis and spermatozoa. Plateau pika (Ochotona curzoniae), belonging to the genus Ochotona of the Ochotonidea family, is a hypoxia tolerant mammal living at 3000–5000 m above sea levelon the Qinghai-Tibet Plateau. We found that the expression pattern of six LDH isoenzymes in the somatic tissues of female and male plateau pikas to be the same as those in testis and sperm, suggesting that LDH-C4 was expressed in somatic tissues of plateau pika. Here we report the detection of LDHC in the somatic tissues of plateau pika using RT-PCR, Western blotting and immunohistochemistry. Our results indicate that Ldh-c mRNA is transcribed in the heart, liver, lung, kidney, brain, skeletal muscle and testis. In somatic tissues LDHC was translated in the cytoplasm, while in testis it was expressed in both cytoplasm and mitochondria. The third band from cathode to anode in LDH isoenzymes was identified as LDH-C4. The finding that Ldh-c is expressed in both somatic tissues and testis of plateau pika provides important implications for more in-depth research into the Ldh-c function in mammals. PMID:23772382

  12. Testis-Specific Lactate Dehydrogenase (LDH-C4) in Skeletal Muscle Enhances a Pika's Sprint-Running Capacity in Hypoxic Environment.

    Science.gov (United States)

    Wang, Yang; Wei, Lian; Wei, Dengbang; Li, Xiao; Xu, Lina; Wei, Linna

    2015-08-07

    LDH-C4 is a lactate dehydrogenase that catalyzes the conversion of pyruvate to lactate. In mammals, ldh-c was originally thought to be expressed only in testis and spermatozoa. Plateau pika (Ochotona curzoniae), which belongs to the genus Ochotona of the Ochotonidea family, is a hypoxia tolerant mammal living 3000-5000 m above sea level on the Qinghai-Tibet Plateau, an environment which is strongly hypoxic. Ldh-c is expressed not only in testis and sperm but also in somatic tissues of plateau pika. In this study, the effects of N-propyl oxamate and N-isopropyl oxamate on LDH isozyme kinetics were compared to screens for a selective inhibitor of LDH-C4. To reveal the role and physiological mechanism of LDH-C4 in skeletal muscle of plateau pika, we investigated the effect of N-isopropyl oxamate on the pika exercise tolerance as well as the physiological mechanism. Our results show that Ki of N-propyl oxamate and N-isopropyl oxamate for LDH-A4, LDH-B4, and LDH-C4 were 0.094 mmol/L and 0.462 mmol/L, 0.119 mmol/L and 0.248 mmol/L, and 0.015 mmol/L and 0.013 mmol/L, respectively. N-isopropyl oxamate is a powerful selective inhibitor of plateau pika LDH-C4. In our exercise tolerance experiment, groups treated with inhibitors had significantly lower swimming times than the uninhibited control group. The inhibition rates of LDH, LD, and ATP were 37.12%, 66.27%, and 32.42%, respectively. Our results suggested that ldh-c is expressed in the skeletal muscle of plateau pika, and at least 32.42% of ATP in the skeletal muscle is catalyzed by LDH-C4 by anaerobic glycolysis. This suggests that pika has reduced dependence on oxygen and enhanced adaptation to hypoxic environment due to increased anaerobic glycolysis by LDH-C4 in skeletal muscle. LDH-C4 in plateau pika plays the crucial role in anaerobic glycolysis and generates ATP rapidly since this is the role of LDH-A4 in most species on plain land, which provide evidence that the native humans and animals in Qinghai-Tibet plateau

  13. Characterization of H7N2 Avian Influenza Virus in Wild Birds and Pikas in Qinghai-Tibet Plateau Area.

    Science.gov (United States)

    Su, Shuo; Xing, Gang; Wang, Junhua; Li, Zengkui; Gu, Jinyan; Yan, Liping; Lei, Jing; Ji, Senlin; Hu, Boli; Gray, Gregory C; Yan, Yan; Zhou, Jiyong

    2016-08-24

    Qinghai Lake is a major migrating bird breeding site that has experienced several recent highly pathogenic avian influenza virus (HPAIV) epizootics. From 2006 to 2009 we studied Qinghai's wild birds and pikas for evidence of AIV infections. We sampled 941 healthy wild animals and isolated seventeen H7N2 viruses (eight from pikas and nine from wild birds). The H7N2 viruses were phylogenetically closely related to each other and to viruses isolated in Hong Kong in the 1970s. We determined the pathogenicity of the H7N2 viruses by infecting chickens and mice. Our results suggest that pikas might play an important role in the ecology of AIVs, acting as intermediate hosts in which viruses become more adapted to mammals. Our findings of AI infection in pikas are consistent with previous observations and raise the possibility that pikas might play a previously unrecognized role in the ecology of AIVs peridomestic aquatic environments.

  14. Revisiting the past to foretell the future: summer temperature and habitat area predict pika extirpations in California

    Science.gov (United States)

    Joseph A. E. Stewart; John D. Perrine; Lyle B. Nichols; James H. Thorne; Constance I. Millar; Kenneth E. Goehring; Cody P. Massing; David H. Wright; Brett Riddle

    2015-01-01

    Aim The American pika (Ochotona princeps) appears to have experienced climate mediated upslope range contraction in the Great Basin of North America, but this result has not yet been extended to other portions of the pika’s range. Our goals were: first, to determine the environmental parameters that most influence...

  15. The seasonal changes of plant secondary metabolites and their influence on the food selection of plateau pika%植物次生代谢物含量的季节性变化及其对高原鼠兔食物选择的影响

    Institute of Scientific and Technical Information of China (English)

    戴鑫; 顾新州; 石佳; 袁飞; 殷宝法; 王爱勤; 魏万红; 杨生妹

    2012-01-01

    The research was carried out from June to September 2008 in the Haibei Alpine Meadow Ecosystem Research Station, Chinese Academy of Science, Qinghai Province. Plateau pikas (Ochotona curzoniae) were fed 20 different plants and the amounts of consumed food were measured using a cafeteria preference test. Seasonal changes of 4 plant secondary metabolites (PSMs) , flavonoids, condensed tannins, simple phenols and total phenols in the 20 plants were determined by ultraviolet spectrophotometer. The results for the 20 plants showed that the groups of favored plants and edible plants for plateau pikas comprised 7 species each, the remaining 6 species were anorectic plants. There were some differences between plant species for the 4 PSMs some of which showed seasonal changes - they tended to be the lowest in the beginning of growing season and gradually increased in the following months. The contents of condensed tannins in the favored group was significantly lower than in the edible group, and the content of flavonoids in the favored group was significantly lower than in the anorectic group. There was a significant negative correlation between the amount of food intake and the contents of flavonoids in all 20 plants. Within the favored plant group, the plant intake amount was negatively correlated with simple phenols and total phenols content. The results partly verified the hypothesis that plant secondary metabolites serve a defense strategy that could significantly influence the plants' selection as food by Ochotona curzoniae. Flavonoids were the factor which significantly restrained the plant food selection of plateau pikas and condensed tannins could deter the plant food selection of plateau pikas in some extent, and results demonstrated that plateau pikas might have a food selection strategy to forage on the plants with high contents of simple phenols or total phenols in relative small quantities, but avoid foraging them in large doses.%2008年6~9月在中国科

  16. Collared Pikas as a Model Species for Studying the Biological Impacts of Climate Change in Alpine Ecosystems

    Science.gov (United States)

    O'Donovan, K. S.; Hik, D.

    2007-12-01

    Climate models suggest that global temperatures could rise between 1.4° C and 5.8° C over the next 100 years, and that these effects will be most extreme in northern mountain regions. Pikas (Ochotona, Lagomorpha) are widespread small mammals in the alpine environments of Asia and North America. They are cold adapted and consequently sensitive to warming global temperatures. Considerable research has shown a poleward migration of many species as a result of rising temperatures, but high alpine dwelling species, like the pika, may already be trapped at the top of mountains. Little is known about the threshold values of environmental conditions under which pikas either persist or disappear. Collared pikas (Ochotona collaris) inhabit alpine meadows in the Kluane region of the southwest Yukon. Sites located along an environmental gradient from nunataks in the St Elias Icefields to the Ruby Range Mountains have experienced different climatic and glacial histories. Using baseline data from the long-term study in the Ruby Ranges, we report on differences in the ecological and climatic conditions of sites along this gradient and how this translates into differences in the behavioural and population ecology of the pikas living there. By looking at these differences we can infer the potential impacts of a warming climate, and the subsequent ecological changes on collared pika populations in order to clarify the causes of local extinction and allow us to develop models for predicting ecological responses as conditions change under future climate regimes.

  17. Apparent climate-mediated loss and fragmentation of core habitat of the American pika in the Northern Sierra Nevada, California, USA

    Science.gov (United States)

    Joseph A. E. Stewart; David H. Wright; Katherine A. Heckman; Robert Guralnick

    2017-01-01

    Contemporary climate change has been widely documented as the apparent cause of range contraction at the edge of many species distributions but documentation of climate change as a cause of extirpation and fragmentation of the interior of a species' core habitat has been lacking. Here, we report the extirpation of the American pika (Ochotona princeps...

  18. After the frass: foraging pikas select patches previously grazed by caterpillars

    Science.gov (United States)

    Barrio, Isabel C.; Hik, David S.; Peck, Kristen; Bueno, C. Guillermo

    2013-01-01

    Interactions among herbivores can shape the structure of their communities and drive their dynamics. However, detecting herbivore interactions can be challenging when they are deferred in space or time. Moreover, interactions among distantly related groups of herbivores, such as vertebrates and invertebrates, are poorly understood. We investigated the effect of invertebrate herbivory on the subsequent foraging choices of a small alpine-dwelling vertebrate, the collared pika (Ochotona collaris). We carried out a field experiment within pika territories, by presenting them with a choice of foraging sites following manipulation of invertebrate (caterpillar) herbivory. Pikas actively selected areas with increased, recent invertebrate herbivory. While the underlying mechanisms behind this interaction remain unknown, our results demonstrate a positive effect of invertebrate herbivores on subsequent vertebrate foraging preferences for the first time. Even among distantly related taxa, such interactions where one herbivore is cueing on the foraging of another, could drive the creation of herbivory hotspots, with cascading consequences for ecosystem processes. PMID:23616644

  19. 高原鼠兔扰动对高寒草地植物群落特征的影响%Impacts of Ochotona pallasi disturbance on alpine grassland community characteristics

    Institute of Scientific and Technical Information of China (English)

    赵国琴; 李广泳; 马文虎; 赵殿智; 李小雁

    2013-01-01

    Plateau pika is the main fossorial mammal in the alpine grassland in Qinghai Lake Watershed of Northwest China.Based on the field investigation data from 18 alpine grassland quadrats in the Watershed,and by using redundancy analysis (RDA) and the surface fitting offered by ‘ R-Vegan',the disturbance intensity of plateau pika (Ochotona pallasi) was classified as four levels.In order to explore the impacts of plateau pika disturbance on the alpine grassland ecosystem and its grazing quality,the community characteristics under different disturbance intensities by plateau pika were analyzed,and a conceptual model about the alpine grassland community succession was proposed.The results showed that with the increase of the disturbance intensity,the dominant species changed from Juncus roemerianus to Poa pratensis and Laux maritima.When the disturbance was small,the community had high quantitative values of coverage,aboveground biomass,biodiversity,and species richness,but the proportion of weeds was also high.When the disturbance was large,the quantitative values were the lowest,while the proportion of weeds was the highest.When the disturbance was moderate,the community had relatively high quantitative values,and the proportion of grasses and sedges was the highest.It was concluded that the community's characteristic values under low plateau pika disturbance intensity were high but the grazing quality was low,while high disturbance intensity resulted in the grassland degradation.Therefore,the disturbance intensity in the threshold could maintain the stability of alpine grassland ecosystem and improve its grazing quality.%高原鼠兔是青海湖流域高寒草地主要的啮齿动物.本文基于R-Vegan中的RDA排序方法,以有效洞口数差异将高原鼠兔扰动强度划分为4组,分析不同扰动强度下高寒草地植物群落特征,进而提出群落演替的概念模型,探究高原鼠兔扰动对高寒草地生态系统及放牧质量的影响.结果

  20. Effect of Two Sexes Sterile Rodenticide (Neem Oil) on Food Intake of Plateau Pika%两性不育灭鼠剂印楝油对高原鼠兔摄食量的影响及药效试验研究

    Institute of Scientific and Technical Information of China (English)

    龙兴发; 李太强; 殷中琼; 蒋忠荣; 朱连发; 杨秀全

    2011-01-01

    通过对高原鼠兔野外饲养和印楝油摄食量的药效观察试验,选取高原鼠兔90只,分成2个试验组和1个对照组,各试验组投药浓度为30%和40%的印楝油;对照组饲喂青草,用药7d。试验期间观察各组鼠兔的临床表现,每天记录颗粒剂的采食量,并计算摄食系数;停药后27d处死,剖检雄雌鼠,做病理切片,剖开雌鼠子宫,统计怀孕率。结果表明,高原 药浓度 、40%的颗粒剂的摄食率分别为11.09%和25.10%,差异显著(P〈0.05);筛选出主药浓度为40 两性不 颗粒剂适口性良好,对高原鼠兔有良好的抗生%This article carried out, and 90 plateau the study on effect of rodenticide(neem oil) on food intake of plateau pika in the fields was pikas were selected and allocated into two experimental groups and one control group, the concentration of neem oil of

  1. Mechanistic variables can enhance predictive models of endotherm distributions: the American pika under current, past, and future climates.

    Science.gov (United States)

    Mathewson, Paul D; Moyer-Horner, Lucas; Beever, Erik A; Briscoe, Natalie J; Kearney, Michael; Yahn, Jeremiah M; Porter, Warren P

    2017-03-01

    How climate constrains species' distributions through time and space is an important question in the context of conservation planning for climate change. Despite increasing awareness of the need to incorporate mechanism into species distribution models (SDMs), mechanistic modeling of endotherm distributions remains limited in this literature. Using the American pika (Ochotona princeps) as an example, we present a framework whereby mechanism can be incorporated into endotherm SDMs. Pika distribution has repeatedly been found to be constrained by warm temperatures, so we used Niche Mapper, a mechanistic heat-balance model, to convert macroclimate data to pika-specific surface activity time in summer across the western United States. We then explored the difference between using a macroclimate predictor (summer temperature) and using a mechanistic predictor (predicted surface activity time) in SDMs. Both approaches accurately predicted pika presences in current and past climate regimes. However, the activity models predicted 8-19% less habitat loss in response to annual temperature increases of ~3-5 °C predicted in the region by 2070, suggesting that pikas may be able to buffer some climate change effects through behavioral thermoregulation that can be captured by mechanistic modeling. Incorporating mechanism added value to the modeling by providing increased confidence in areas where different modeling approaches agreed and providing a range of outcomes in areas of disagreement. It also provided a more proximate variable relating animal distribution to climate, allowing investigations into how unique habitat characteristics and intraspecific phenotypic variation may allow pikas to exist in areas outside those predicted by generic SDMs. Only a small number of easily obtainable data are required to parameterize this mechanistic model for any endotherm, and its use can improve SDM predictions by explicitly modeling a widely applicable direct physiological effect

  2. Mechanistic variables can enhance predictive models of endotherm distributions: The American pika under current, past, and future climates

    Science.gov (United States)

    Mathewson, Paul; Moyer-Horner, Lucas; Beever, Erik; Briscoe, Natalie; Kearney, Michael T; Yahn, Jeremiah; Porter, Warren P.

    2017-01-01

    How climate constrains species’ distributions through time and space is an important question in the context of conservation planning for climate change. Despite increasing awareness of the need to incorporate mechanism into species distribution models (SDMs), mechanistic modeling of endotherm distributions remains limited in this literature. Using the American pika (Ochotona princeps) as an example, we present a framework whereby mechanism can be incorporated into endotherm SDMs. Pika distribution has repeatedly been found to be constrained by warm temperatures, so we used Niche Mapper, a mechanistic heat-balance model, to convert macroclimate data to pika-specific surface activity time in summer across the western United States. We then explored the difference between using a macroclimate predictor (summer temperature) and using a mechanistic predictor (predicted surface activity time) in SDMs. Both approaches accurately predicted pika presences in current and past climate regimes. However, the activity models predicted 8–19% less habitat loss in response to annual temperature increases of ~3–5 °C predicted in the region by 2070, suggesting that pikas may be able to buffer some climate change effects through behavioral thermoregulation that can be captured by mechanistic modeling. Incorporating mechanism added value to the modeling by providing increased confidence in areas where different modeling approaches agreed and providing a range of outcomes in areas of disagreement. It also provided a more proximate variable relating animal distribution to climate, allowing investigations into how unique habitat characteristics and intraspecific phenotypic variation may allow pikas to exist in areas outside those predicted by generic SDMs. Only a small number of easily obtainable data are required to parameterize this mechanistic model for any endotherm, and its use can improve SDM predictions by explicitly modeling a widely applicable direct physiological effect

  3. The idiosyncrasies of place: geographic variation in the climate-distribution relationships of the American pika.

    Science.gov (United States)

    Jeffress, Mackenzie R; Rodhouse, Thomas J; Ray, Chris; Wolff, Susan; Epps, Clinton W

    2013-06-01

    Although climate acts as a fundamental constraint on the distribution of organisms, understanding how this relationship between climate and distribution varies over a species' range is critical for addressing the potential impacts of accelerated climate change on biodiversity. Bioclimatic niche models provide compelling evidence that many species will experience range shifts under scenarios of global change, yet these broad, macroecological perspectives lack specificity at local scales, where unique combinations of environment, biota, and history conspire against generalizations. We explored how these idiosyncrasies of place affect the climate-distribution relationship of the American pika (Ochotona princeps) by replicating intensive field surveys across bioclimatic gradients in eight U.S. national parks. At macroecological scales, the importance of climate as a constraint on pika distribution appears unequivocal; forecasts suggest that the species' range will contract sharply in coming decades. However, the species persists outside of its modeled bioclimatic envelope in many locations, fueling uncertainty and debate over its conservation status. Using a Bayesian hierarchical approach, we modeled variation in local patterns of pika distribution along topographic position, vegetation cover, elevation, temperature, and precipitation gradients in each park landscape. We also accounted for annual turnover in site occupancy probabilities. Topographic position and vegetation cover influenced occurrence in all parks. After accounting for these factors, pika occurrence varied widely among parks along bioclimatic gradients. Precipitation by itself was not a particularly influential predictor. However, measures of heat stress appeared most influential in the driest parks, suggesting an interaction between the strength of climate effects and the position of parks along precipitation gradients. The combination of high elevation, cold temperatures, and high precipitation

  4. Replicated landscape genetic and network analyses reveal wide variation in functional connectivity for American pikas.

    Science.gov (United States)

    Castillo, Jessica A; Epps, Clinton W; Jeffress, Mackenzie R; Ray, Chris; Rodhouse, Thomas J; Schwalm, Donelle

    2016-09-01

    Landscape connectivity is essential for maintaining viable populations, particularly for species restricted to fragmented habitats or naturally arrayed in metapopulations and facing rapid climate change. The importance of assessing both structural connectivity (physical distribution of favorable habitat patches) and functional connectivity (how species move among habitat patches) for managing such species is well understood. However, the degree to which functional connectivity for a species varies among landscapes, and the resulting implications for conservation, have rarely been assessed. We used a landscape genetics approach to evaluate resistance to gene flow and, thus, to determine how landscape and climate-related variables influence gene flow for American pikas (Ochotona princeps) in eight federally managed sites in the western United States. We used empirically derived, individual-based landscape resistance models in conjunction with predictive occupancy models to generate patch-based network models describing functional landscape connectivity. Metareplication across landscapes enabled identification of limiting factors for dispersal that would not otherwise have been apparent. Despite the cool microclimates characteristic of pika habitat, south-facing aspects consistently represented higher resistance to movement, supporting the previous hypothesis that exposure to relatively high temperatures may limit dispersal in American pikas. We found that other barriers to dispersal included areas with a high degree of topographic relief, such as cliffs and ravines, as well as streams and distances greater than 1-4 km depending on the site. Using the empirically derived network models of habitat patch connectivity, we identified habitat patches that were likely disproportionately important for maintaining functional connectivity, areas in which habitat appeared fragmented, and locations that could be targeted for management actions to improve functional connectivity

  5. How Far into Europe Did Pikas (Lagomorpha: Ochotonidae) Go during the Pleistocene? New Evidence from Central Iberia

    Science.gov (United States)

    Laplana, César; Sevilla, Paloma; Arsuaga, Juan Luis; Arriaza, Mari Carmen; Baquedano, Enrique; Pérez-González, Alfredo

    2015-01-01

    This paper reports the first find of pika remains in the Iberian Peninsula, at a site in central Spain. A fragmented mandible of Ochotona cf. pusilla was unearthed from Layer 3 (deposited some 63.4±5.5 ka ago as determined by thermoluminescence) of the Buena Pinta Cave. This record establishes new limits for the genus geographic distribution during the Pleistocene, shifting the previous edge of its known range southwest by some 500 km. It also supports the idea that, even though Europe’s alpine mountain ranges represented a barrier that prevented the dispersal into the south to this and other taxa of small mammals from central and eastern Europe, they were crossed or circumvented at the coldest time intervals of the end of the Middle Pleistocene and of the Late Pleistocene. During those periods both the reduction of the forest cover and the emersion of large areas of the continental shelf due to the drop of the sea level probably provided these species a way to surpass this barrier. The pika mandible was found accompanying the remains of other small mammals adapted to cold climates, indicating the presence of steppe environments in central Iberia during the Late Pleistocene. PMID:26535576

  6. Pika and vole mitochondrial genomes increase support for both rodent monophyly and glires.

    Science.gov (United States)

    Lin, Yu-Hsin; Waddell, Peter J; Penny, David

    2002-07-10

    Complete mitochondrial genomes are reported for a pika (Ochotona collaris) and a vole (Volemys kikuchii) then analysed together with 35 other mitochondrial genomes from mammals. With standard phylogenetic methods the pika joins with the other lagomorph (rabbit) and the vole with the other murid rodents (rat and mouse). In addition, with hedgehog excluded, the seven rodent genomes consistently form a homogeneous group in the unrooted placental tree. Except for uncertainty of the position of tree shrew, the clade Glires (monophyletic rodents plus lagomorphs) is consistently found. The unrooted tree obtained by ProtML (Protein Maximum Likelihood, a program in MOLPHY) is compatible with a reclassification of mammals [Syst. Biol. 48, 1-5 (1999)] which is also supported by other recent studies. However, when this tree is rooted with marsupials plus platypus, the outgroup often joins the lineage leading to the three murid rodents, so the rodents are no longer monophyletic. Apart from misplacing the root, the presence of the outgroups also distorts other parts of the unrooted tree. Either constraining the tree to maintain rodents monophyletic, or omitting murids, maintains the ingroup tree and sees the outgroup join on the edge to Xenarthra, to Afrotheria, or to these two groups together. This emphasises the importance of carrying out both an unrooted and a rooted analysis. It is known from cancer research that murid rodents have reduced activity in some DNA repair mechanisms and this alters their substitution pattern - this may be the case for mitochnodrial DNA as well. Comparing nucleotide compositions may identify taxa that differ in aspects of their DNA repair mechanisms.

  7. PIKA as an Adjuvant Enhances Specific Humoral and Cellular Immune Responses Following the Vaccination of Mice with HBsAg plus PIKA

    Institute of Scientific and Technical Information of China (English)

    Erxia Shen; Li Li; Lietao Li; Lianqiang Feng; Lin Lu; Ziliang Yao; Haixiang Lin; Changyou Wu

    2007-01-01

    An adjuvant is usually used to enhance the immune response induced by vaccines. The choice of adjuvant or immune enhancer determines the effectiveness of the immune response. Currently, aluminium (Alum, a generic term for salts of aluminium) is the only FDA-approved adjuvant. Alum predominantly induces the differentiation of Th2 cells and thus mediates an antibody immune response. Therefore, there is an urgent need for new adjuvants that enhance not only humoral but also cellular immune responses. In the present study, we demonstrates that PIKA (a stabilized dsRNA) as an adjuvant directly induces the activation and the proliferation of both B and NK cells in vitro. Injection of PIKA into mice results in the production of cytokines in vivo. In addition, the study demonstrates that PIKA promotes the maturation of bone marrow-derived dendritic cells (BMDCs) including up-regulation of the co-stimulatory molecules CD80, CD86 and CD40, and the induction of cytokines such as IL-12p70, IL-12p40 and IL-6. Importantly, after immunization of mice with HBsAg plus PIKA, the presence of PIKA enhances the titers of HBsAg-specific IgG and HBsAg-specific IFN-γ production. These results demonstrate that PIKA as an adjuvant can promote both humoral and cellular immune responses. These might have an implication in applying PIKA as an adjuvant to be used in the design and development of both therapeutic and preventive vaccines, and used in the clinical study.

  8. Adjuvant PIKA protects hepatoma cells from dengue virus infection by promoting a TBK-1-dependent innate immune response.

    Science.gov (United States)

    Zhang, Ping; Wu, Siyu; Li, Lietao; Liang, Zhaoduan; Li, Yuye; Feng, Lianqiang; Huang, Xi

    2013-04-01

    Our study presents a first investigation of the effect of the adjuvant PIKA on dengue virus (DENV) replication. PIKA pretreatment decreased the levels of DENV serotype 2 (DENV2) mRNA, protein and viral particles in the hepatoma cell line HepG2. Treatment with PIKA simultaneously with DENV2 infection, but not after infection, resulted in a protective effect. Significant induction of type I and type III interferons (IFNs), as well as interferon-stimulated genes was detected in PIKA-pretreated cells. Neutralization of IFN-β partially restored the replication levels of DENV2 in PIKA-pretreated cells, suggesting that IFN-β is one of the mediators involved in the antiviral action of PIKA. Additionally, blockade of TBK-1 signaling largely restored the IFN induction and viral suppression effects mediated by PIKA, further illustrating that PIKA plays its anti-DENV role by promoting innate immunity. These findings suggest that PIKA is an attractive agent to be used in the prevention of DENV diseases.

  9. A novel rabies vaccine based-on toll-like receptor 3 (TLR3) agonist PIKA adjuvant exhibiting excellent safety and efficacy in animal studies

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yi [Yisheng Biopharma. Co., Ltd., Beijing (China); Zhang, Shoufeng [Academy of Military Medical Sciences, Changchun (China); Li, Wei [National Center for Safety Evaluation of Drugs, Beijing (China); Hu, Yuchi; Zhao, Jinyan [Beijing Institute for Drug Control, Beijing (China); Liu, Fang; Lin, Haixiang; Liu, Yuan; Wang, Liliang; Xu, Shu [Yisheng Biopharma. Co., Ltd., Beijing (China); Hu, Rongliang, E-mail: ronglianghu@hotmail.com [Academy of Military Medical Sciences, Changchun (China); Shao, Hui, E-mail: hui.shao@yishengbio.com [Yisheng Biopharma. Co., Ltd., Beijing (China); Li, Lietao, E-mail: lietao.li@gmail.com [Yisheng Biopharma. Co., Ltd., Beijing (China)

    2016-02-15

    Vaccination alone is not sufficiently effective to protect human from post-exposure rabies virus infection due to delayed generation of rabies virus neutralizing antibodies and weak cellular immunity. Therefore, it is vital to develop safer and more efficacious vaccine against rabies. PIKA, a stabilized chemical analog of double-stranded RNA that interacts with TLR3, was employed as adjuvant of rabies vaccine. The efficacy and safety of PIKA rabies vaccine were evaluated. The results showed that PIKA rabies vaccine enhanced both humoral and cellular immunity. After viral challenge, PIKA rabies vaccine protected 70–80% of animals, while the survival rate of non-adjuvant vaccine group (control) was 20–30%. According to the results of toxicity tests, PIKA and PIKA rabies vaccine are shown to be well tolerated in mice. Thus, this study indicates that PIKA rabies vaccine is an effective and safe vaccine which has the potential to develop next-generation rabies vaccine and encourage the start of clinical studies. - Highlights: • Vaccination alone is not effective to protect human from rabies virus infection due to delayed generation of rabies virus neutralizing antibodies (RVNA) and weak cellular immunity. • Therefore, it is vital to develop safer and more efficacious vaccine against rabies. PIKA, a stabilized chemical analog of double-stranded RNA that interacts with TLR3, was employed as an adjuvant of rabies vaccine. • The efficacy and safety of PIKA rabies vaccine was evaluated in mice. • The results showed that PIKA rabies vaccine enhanced both humoral and cellular immunity. • After viral challenge, PIKA rabies vaccine protected 70–80% of animals, while the survival rate of non-adjuvant vaccine group was only 20–30%. • According to the results of toxicity tests, PIKA and PIKA rabies vaccine are shown to be well tolerated in mice. • Thus, this study indicates that PIKA rabies vaccine is an effective and safe vaccine which has the potential to

  10. Testis-Specific Lactate Dehydrogenase (LDH-C4) in Skeletal Muscle Enhances a Pika’s Sprint-Running Capacity in Hypoxic Environment

    Science.gov (United States)

    Wang, Yang; Wei, Lian; Wei, Dengbang; Li, Xiao; Xu, Lina; Wei, Linna

    2015-01-01

    LDH-C4 is a lactate dehydrogenase that catalyzes the conversion of pyruvate to lactate. In mammals, ldh-c was originally thought to be expressed only in testis and spermatozoa. Plateau pika (Ochotona curzoniae), which belongs to the genus Ochotona of the Ochotonidea family, is a hypoxia tolerant mammal living 3000–5000 m above sea level on the Qinghai-Tibet Plateau, an environment which is strongly hypoxic. Ldh-c is expressed not only in testis and sperm but also in somatic tissues of plateau pika. In this study, the effects of N-propyl oxamate and N-isopropyl oxamate on LDH isozyme kinetics were compared to screens for a selective inhibitor of LDH-C4. To reveal the role and physiological mechanism of LDH-C4 in skeletal muscle of plateau pika, we investigated the effect of N-isopropyl oxamate on the pika exercise tolerance as well as the physiological mechanism. Our results show that Ki of N-propyl oxamate and N-isopropyl oxamate for LDH-A4, LDH-B4, and LDH-C4 were 0.094 mmol/L and 0.462 mmol/L, 0.119 mmol/L and 0.248 mmol/L, and 0.015 mmol/L and 0.013 mmol/L, respectively. N-isopropyl oxamate is a powerful selective inhibitor of plateau pika LDH-C4. In our exercise tolerance experiment, groups treated with inhibitors had significantly lower swimming times than the uninhibited control group. The inhibition rates of LDH, LD, and ATP were 37.12%, 66.27%, and 32.42%, respectively. Our results suggested that ldh-c is expressed in the skeletal muscle of plateau pika, and at least 32.42% of ATP in the skeletal muscle is catalyzed by LDH-C4 by anaerobic glycolysis. This suggests that pika has reduced dependence on oxygen and enhanced adaptation to hypoxic environment due to increased anaerobic glycolysis by LDH-C4 in skeletal muscle. LDH-C4 in plateau pika plays the crucial role in anaerobic glycolysis and generates ATP rapidly since this is the role of LDH-A4 in most species on plain land, which provide evidence that the native humans and animals in Qinghai

  11. Testis-Specific Lactate Dehydrogenase (LDH-C4 in Skeletal Muscle Enhances Apika’s Sprint-Running Capacity in Hypoxic Environment

    Directory of Open Access Journals (Sweden)

    Yang Wang

    2015-08-01

    Full Text Available LDH-C4 is a lactate dehydrogenase that catalyzes the conversion of pyruvate to lactate. In mammals, ldh-c was originally thought to be expressed only in testis and spermatozoa. Plateau pika (Ochotona curzoniae, which belongs to the genus Ochotona of the Ochotonidea family, is a hypoxia tolerant mammal living 3000–5000 m above sea level on the Qinghai-Tibet Plateau, an environment which is strongly hypoxic. Ldh-c is expressed not only in testis and sperm but also in somatic tissues of plateau pika. In this study, the effects of N-propyl oxamate and N-isopropyl oxamate on LDH isozyme kinetics were compared to screens for a selective inhibitor of LDH-C4. To reveal the role and physiological mechanism of LDH-C4 in skeletal muscle of plateau pika, we investigated the effect of N-isopropyl oxamate on the pika exercise tolerance as well as the physiological mechanism. Our results show that Ki of N-propyl oxamate and N-isopropyl oxamate for LDH-A4, LDH-B4, and LDH-C4 were 0.094 mmol/L and 0.462 mmol/L, 0.119 mmol/L and 0.248 mmol/L, and 0.015 mmol/L and 0.013 mmol/L, respectively. N-isopropyl oxamate is a powerful selective inhibitor of plateau pika LDH-C4. In our exercise tolerance experiment, groups treated with inhibitors had significantly lower swimming times than the uninhibited control group. The inhibition rates of LDH, LD, and ATP were 37.12%, 66.27%, and 32.42%, respectively. Our results suggested that ldh-c is expressed in the skeletal muscle of plateau pika, and at least 32.42% of ATP in the skeletal muscle is catalyzed by LDH-C4 by anaerobic glycolysis. This suggests that pika has reduced dependence on oxygen and enhanced adaptation to hypoxic environment due to increased anaerobic glycolysis by LDH-C4 in skeletal muscle. LDH-C4 in plateau pika plays the crucial role in anaerobic glycolysis and generates ATP rapidly since this is the role of LDH-A4 in most species on plain land, which provide evidence that the native humans and animals in

  12. Critical Analysis of a Social and Scientific Moral Dilemma: Fifth Graders and Veterans Respond to "Hiroshima No Pika."

    Science.gov (United States)

    Storey, Dee

    This document presents results of a survey studying the Japanese picture book, "Hiroshima No Pika." The story aptly captures how a family of three find their lives shattered in a matter of seconds when the atomic bomb is dropped on Hiroshima (Japan) in World War II. Issues presented in the story are: (1) immediate survival in the face of…

  13. PIKA Provides an Adjuvant Effect to Induce Strong Mucosal and Systemic Humoral Immunity Against SARS-CoV

    Institute of Scientific and Technical Information of China (English)

    Wei-wei Gai; Yan Zhang; Di-han Zhou; Yao-qing Chen; Jing-yi Yang; Hui-min Yan

    2011-01-01

    Severe Acute Respiratory Syndrome(SARS)is a deadly infectious disease caused by SARS Coronavirus(SARS-CoV).Inactivated SARS-CoV has been explored as a vaccine against SARS-CoV.However,safe and potent adjuvants,especially with more efficient and economical needle-free vaccination are always needed more urgently in a pandemic.The development of a safe and effective mucosal adjuvant and vaccine for prevention of emergent infectious diseases such as SARS will be an important advancement.PIKA,a stabilized derivative of Poly(I:C),was previously reported to be safe and potent as adjuvant in mouse models.In the present study,we demonstrated that the intraperitoneal and intranasal co-administration of inactivated SARS-CoV vaccine together with this improved Poly(I:C)derivative induced strong anti-SARS-CoV mucosal and systemic humoral immune responses with neutralizing activity against pseudotyped virus.Although intraperitoneal immunization of inactivated SARS-CoV vaccine alone could induce a certain level of neutralizing activity in serum as well as in mucosal sites,co-administration of inactivated SARS-CoV vaccine with PIKA as adjuvant could induce a much higher neutralizing activity.When intranasal immunization was used,PIKA was obligatorily for inducing neutralizing activity in serum as well as in mucosal sites and was correlated with both mucosal IgA and mucosal IgG response.Overall,PIKA could be a good mucosal adjuvant candidate for inactivated SARS-CoV vaccine for use in possible future pandemic.

  14. Tibial Plateau Fractures

    DEFF Research Database (Denmark)

    Elsøe, Rasmus

    This PhD thesis reported an incidence of tibial plateau fractures of 10.3/100,000/year in a complete Danish regional population. The results reported that patients treated for a lateral tibial plateau fracture with bone tamp reduction and percutaneous screw fixation achieved a satisfactory level...... with only the subgroup Sport significantly below the age matched reference population. The thesis reports a level of health related quality of life (Eq5d) and disability (KOOS) significantly below established reference populations for patients with bicondylar tibial plateau fracture treated with a ring...... fixator, both during treatment and at 19 months following injury. In general, the thesis demonstrates that the treatment of tibial plateau fractures are challenging and that some disabilities following these fractures must be expected. Moreover, the need for further research in the area, both with regard...

  15. Limb preference in the gallop of dogs and the half-bound of pikas on flat ground

    CERN Document Server

    Hackert, Rémi; Herbin, Marc; Abourachid, Anick; Libourel, P A

    2008-01-01

    During fast locomotion - gallop, half bound - of quadruped mammals, the ground contact of the limbs in each pair do not alternate symmetrically. Animals using such asymmetrical gait thus choose whether the left or the right limb will contact the ground first, and this gives rise to limb preference. Here, we report that dogs (Mammalia, Carnivora) and pikas (Mammalia, Lagomorpha) prefer one forelimb as trailing limb and use it as such almost twice as often as the other. We also show that this choice depends on the individual and is not a characteristic of the species, and that the strength of the preference was not dependent on the animal's running speed.

  16. CENTRAL PLATEAU REMEDIATION

    Energy Technology Data Exchange (ETDEWEB)

    ROMINE, L.D.

    2006-02-01

    A systematic approach to closure planning is being implemented at the Hanford Site's Central Plateau to help achieve the goal of closure by the year 2035. The overall objective of Central Plateau remediation is to protect human health and the environment from the significant quantity of contaminated material that resulted from decades of plutonium production in support of the nation's defense. This goal will be achieved either by removing contaminants or placing the residual contaminated materials in a secure configuration that minimizes further migration to the groundwater and reduces the potential for inadvertent intrusion into contaminated sites. The approach to Central Plateau cleanup used three key concepts--closure zones, closure elements, and closure process steps--to create an organized picture of actions required to complete remediation. These actions were merged with logic ties, constraints, and required resources to produce an integrated time-phased schedule and cost profile for Central Plateau closure. Programmatic risks associated with implementation of Central Plateau closure were identified and analyzed. Actions to mitigate the most significant risks are underway while high priority remediation projects continue to make progress.

  17. Radiative plateau inflation

    CERN Document Server

    Ballesteros, Guillermo

    2016-01-01

    We describe how monomial chaotic inflation becomes compatible with the latest CMB data thanks to radiative corrections producing a plateau. The interactions of the inflation with other fields, required for reheating, can flatten the potential and moderate the production of primordial gravitational waves, keeping these below the current upper bound. We show that the appearance of a plateau requires that the inflaton couples to fermions and to another scalar or a gauge group. We give concrete examples of minimal particle physics models leading to plateaus for quadratic and quartic chaotic inflation. We also provide a three-parameter model-independent description of radiatively corrected inflation that is amenable to CMB analyses.

  18. Plateau Indian Ways with Words

    Science.gov (United States)

    Monroe, Barbara

    2009-01-01

    The indigenous rhetoric of the Plateau Indians continues to exert a discursive influence on student writing in reservation schools today. Plateau students score low on state-mandated tests and on college writing assignments, in large part because the pervasive personalization of Plateau rhetoric runs counter to the depersonalization of academic…

  19. Greening the Plateau

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Located on the world’s largest plateau, Tibet Autonomous Region in China’s southwest has an average elevation of 4,000 meters. Tibet’s diverse natural landscapes, including snow-capped mountains, vast pastures and virgin forests, combined with its

  20. Advances in Research on Hypoxia Adaptation Mechanisms of Native Plateau Animals%高原土生动物低氧适应机制研究进展

    Institute of Scientific and Technical Information of China (English)

    申健(综述); 牛廷献(审校); 史智勇

    2015-01-01

    Plateau hypoxia adaptation is the core of the plateau medical research , the mechanism of which is mainly a series of complex compensatory established around the hypoxia .Native plateau animals are ideal models of plateau hypoxia adaptation research.Based on the Tibetan pig,plateau pika,the Tibetan ante-lope and Juema minipig,researchers conducted basic research on their characteristics of hematology,pulmo-nary vascular structure and function,hypoxia adaptation related genes,etc.,but there is not enough research on the cellular and molecular level.Research on native plateau animals of hypoxia adaptation mechanisms can provide theoretical basis for the study and development of the plateau experimental animals .%高原低氧适应是高原医学研究的核心,高原低氧适应的机制主要是围绕缺氧而建立起的一系列复杂的代偿。高原土生动物是研究高原低氧适应的理想模型,以藏猪、高原鼠兔、藏羚羊和蕨麻小型猪为例,研究者们多以其血液学特征、肺血管结构和功能及低氧适应相关基因等方面作为基础研究,但目前在细胞及分子水平研究不够深入,研究土生动物低氧适应机制,可以为高原实验动物的开发研究提供理论基础。

  1. Institute of Tibetan Plateau Research

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ The Tibetan Plateau (Qinghai-Xizang Plateau)is a unique geological-geographical unit on Earth, an ideal region for studies into the formation and evolution of the lithosphere and the dynamic mechanism of the earth crust. The uplifting of the Plateau exerts profound influence upon the evolution and differentiation of the natural environment of the plateau itself, its adjacent regions and the Northern Hemisphere. As a unique natural geographical unit, the Plateau holds a special status in the whole globe due to its special natural environment and ecosystems, which is also in close relation to global environmental change.The significance of the Plateau research should be recognized not only in the fundamental research fields of geo-sciences and biology, but also in its application to resource exploitation, environmental protection and sustainable development of the Plateau region.

  2. Ground Wave Emergency Network Final Operational Capability: Environmental Assessment for Central Utah Relay Node, Site Number RN 8C920UT

    Science.gov (United States)

    1993-04-16

    white strobe light at the top, which emits 40 flashes per minute and is rated at 20,000 candelas for daytime and twilight use and 2,000 candelas for...lynx Felix lynx canadensis North American wolverine Gulo gulo luscus Wasatch pika Ochotona princeps wasatchensis Heliotrope pika Ochotona princeps...free oxygen Aquifer A water-bearing stratum of permeable rock, sand, or gravel D-5 Candela A unit of meastre of the in.ensity of light eoual to the

  3. CENTRAL PLATEAU REMEDIATION OPTIMIZATION STUDY

    Energy Technology Data Exchange (ETDEWEB)

    BERGMAN, T. B.; STEFANSKI, L. D.; SEELEY, P. N.; ZINSLI, L. C.; CUSACK, L. J.

    2012-09-19

    THE CENTRAL PLATEAU REMEDIATION OPTIMIZATION STUDY WAS CONDUCTED TO DEVELOP AN OPTIMAL SEQUENCE OF REMEDIATION ACTIVITIES IMPLEMENTING THE CERCLA DECISION ON THE CENTRAL PLATEAU. THE STUDY DEFINES A SEQUENCE OF ACTIVITIES THAT RESULT IN AN EFFECTIVE USE OF RESOURCES FROM A STRATEGIC PERSPECTIVE WHEN CONSIDERING EQUIPMENT PROCUREMENT AND STAGING, WORKFORCE MOBILIZATION/DEMOBILIZATION, WORKFORCE LEVELING, WORKFORCE SKILL-MIX, AND OTHER REMEDIATION/DISPOSITION PROJECT EXECUTION PARAMETERS.

  4. Posterior bicondylar tibial plateau fractures.

    Science.gov (United States)

    Carlson, DuWayne A

    2005-02-01

    To present a case series of patients with posterior bicondylar tibial plateau fractures treated by direct fracture exposure and fixation through dual incisions. Retrospective clinical study. Level 1 trauma centers. Eight patients were identified that had posterior bicondylar tibial plateau fractures. Two patients had depressed posterolateral tibial plateau fractures with contained defects and did not have direct fracture exposure. One patient died of medical problems leaving 5 patients who underwent direct fracture exposure, reduction, and fixation. Posteromedial followed by posterolateral open reduction and internal fixation of posterior bicondylar tibial plateau fractures. At 6 to 24 months follow-up (mean 13 months), all patients returned to near full activities, each with aching after prolonged standing (8-hour shift). Range of motion averaged 2 degrees to 121 degrees of flexion. Three of 5 returned to manual labor jobs; the others were not employed at the time of injury. Posterior bicondylar tibial plateau fractures have a high association with lateral meniscal pathology and can be associated with anterior cruciate ligament injury. Reduction of the posterior plateau condyles is easiest with the knee in full extension. Flexion contractures can be a problem, and patients should be encouraged to regain/maintain knee extension. The dual-incision approach to these challenging fractures can result in good to excellent knee function for these patients.

  5. Science Challenges in Supporting Adaptation Planning in Mountainous Terrain: Lessons from the NOAA climate assessment to inform the FWS Status Review of the American pika

    Science.gov (United States)

    Ray, A. J.; Barsugli, J. J.; Eischeid, J.; Wolter, K.

    2010-12-01

    This presentation will summarize results and some of the scientific challenges that were faced in preparing a NOAA rapid assessment of climate provided as input to the Fish & Wildlife Service review of the American Pika to determine if climate change risks warranted listing the species as endangered. NOAA provided FWS with an assessment of climate observations and projections of change in pika habitat, as a climatological context for the status review. We provided western regional detail based on existing observations and IPCC model projections and new findings from interpreting those observations and projections at smaller spatial scales. A key finding of the report is the large spatial scale of recent and projected warming trends in the West. The 2050 summer temperature projections average about 3°C higher than recent climatology for most of the western U.S., and for 22 locations representative of pika habitats. Statistically downscaled temperature projections were used to relate these large-scale trends to habitat elevation bands. Finally, we provided an expert judgment on the “foreseeable future” for climate for the review. This project required considering the observations and projections in the context of the heterogeneous terrain that is the habitat for many pika populations, and interpreting and interpolating information from often distant observing stations, or large-scale model grid-boxes to make inferences about conditions at finer scales. This presentation will discuss the findings of the report, and some of the strategies that we adopted for analyzing and presenting climate projections. The emphasis will be on this real-world example where time and resource constraints were paramount, as well as the need to use “best available science,” in the context of a formal policy process vs. time to develop new work. Some of the challenges we faced are applicable to many ecological applications and for many individual species, including the choice of

  6. The Pajarito Plateau: a bibliography

    Science.gov (United States)

    Mathien, Frances Joan; Steen, Charlie R.; Allen, Craig D.

    1993-01-01

    This bibliography is the result of two initially independent projects. As the consulting archaeologist at Los Alamos National Laboratory (LANL), Charlie R. Steen collected entries at the suggestion of the staff of the Environmental Surveillance Group of the Health, Safety, and Environmental Division, HSE-8. The primary purpose was to aid the staff in evaluating cultural resources on LANL lands. In addition to works that related to the archaeology and history of the area, Steen included notations of a few books and articles in other fields such as geology and natural history. It was hoped that they also would be of value to other organizations and to students of past human activities on the Pajarito Plateau.At the same time, the National Park Service (NPS) was planning a major survey of Bandelier National Monument (BNM). As part of this plan, the author was asked to prepare a background document that described research previously carried out in the area, including an annotated bibliography. Although the survey would be limited to the park boundaries, the larger Pajarito Plateau is a more logical study area from physiographic, environmental, and cultural perspectives; hence the focus was on this larger region. Mathien (1986) also included some references to natural resources studies, particularly those initiated by NPS within Bandelier National Monument.Both bibliographies were made available to Colleen Olinger and Beverly Larson of the Health and Environmental Services Group at Los Alamos. They realized that while neither was complete, each included entries missing from the other. Larson suggested the two bibliographies be combined. (At this time, Craig Allen was studying the landscape of the Jemez Mountains [Allen 1984c, 1989]. His investigations included much detailed information on natural resource studies and were added in 1991 and 1992.)To limit the scope of their work, Steen and Mathien had chosen their parameter: the Pajarito Plateau. Geographically, the

  7. Monuments of the Giza Plateau

    Science.gov (United States)

    Ruggles, Clive L. N.

    The colossal pyramids of the pharaohs Khufu (Cheops), Khafre (Chephren), and Menkaure (Mycerinus) have attracted a huge amount of astronomical interest over the years, both scholarly and popular. Less attention is usually given to the broader context of structures on the Giza Plateau. One of the most notorious ideas connecting the Giza Plateau with astronomy is that the three large pyramids are laid out on the ground so as to reflect the appearance of the three stars of Orion's Belt in the sky. This idea is unsupportable for several reasons but has succeeded in generating huge public interest. Of much greater serious interest is the fact that the three main pyramids were oriented cardinally to extraordinary precision, which raises the questions of why this was important and how it was achieved. Another idea that has attracted serious attention but also some confusion is that the orientations of some narrow shafts within Khufu's pyramid might have been deliberately aligned upon particular stars. The overall layout of monuments on the plateau may certainly have been designed so as to emphasize certain solar phenomena, for symbolic and ideological reasons relating to a dominant sun cult. It is also possible that it formed part of a wider cosmological "master plan" extending to other pyramids and temples up to 20 km distant.

  8. Biodiversity and conservation in the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The Tibetan Plateau (Qinghai-Xizang Plateau) is a unique biogeographic region in the world, where various landscapes, altitudinal belts, alpine ecosystems, and endangered and endemic species have been developed. A total of 26 altitudinal belts, 28 spectra of altitudinal belts, 12,000 species of vascular plant, 5,000 species of epiphytes, 210 species of mammals, and 532 species of birds have been recorded. The plateau is also one of the centers of species formation and differentiation in the world. To protect the biodiversity of the plateau, about 80 nature reserves have been designated, of which 45 are national or provincial, covering about 22% of the plateau area. Most of the nature reserves are distributed in the southeastern plateau. Recently, the Chinese government has initiated the "Natural Forests Protection Project of China,' mainly in the upper reaches of the Yangtze and Yellow rivers. "No logging" policies have been made and implemented for these areas.

  9. Exploration in Newnes Plateau, NSW

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, P.; McQuade, C. [Pasminco Port Pirie Smelter, NSW (Australia)

    1999-06-01

    Underground coal mining operations in the Western Coalfields of NSW extend into the Newnes Plateau area. The Newnes Plateau area is known for its floral diversity and distinctive topography. A quantitative flora assessment concerning rehabilitation performance of exploration sites was undertaken to refine the environmental component of the exploration process and identify practices that may assist in an improved rate of regeneration within disturbed areas. This article briefly summarises the method and key outcomes of the study, undertaken as part of an Honours Degree program. Surveys of sites showed that plant height was reduced due to vehicle traffic compacting soil, and this also led to a reduced number of plant species and a reduced number of seedlings germinating. Percentage litter cover was found to be positively correlated with the number of species on the sites and the percent plant cover of the regenerating vegetation, shallow surface ripping is recommended to relieve soil compaction. Seeds should be collected from exploration sites prior to disturbance, particularly of species like Banksia and Haken that retain their seed on the plant. Seed should then be dispersed after work has finished. 1 fig., 2 photos.

  10. Prehistoric human settling on the Tibetan Plateau

    Science.gov (United States)

    Chen, Fahu; Zhang, Dongju; Dong, Guanghui

    2017-04-01

    When and where did human first settle down on the Tibetan Plateau is under hot debate among archaeologist, anthropologists, geneticist and paleo-geographers. Based on systematic archaeological, chronological and archaeo-botanical studies of 53 sites in Northeastern Tibetan Plateau, we propose that agriculture facilitated human permanent settlement on the Tibetan Plateau initially since 5200 years ago below 2500 masl and since 3600 years ago up to around 4000 masl, possibly assisted by domesticated animals (Chen et al. 2015). By studying hand- and footprints in Chusang, Meyer et al. (2016) argue that hunter-gatherers permanently occupied central Tibetan Plateau in early Holocene without the help of agriculture. However, we think the limited hand- and footprints evidence found in Chusang could indicate no more than prehistoric hunter-gatherers presence on the remote central Tibetan Plateau in the early Holocene. In addition, by reviewing all the published archaeological data, we propose that human migrated to the Tibetan Plateau from the last Deglacial period to late Holocene mainly from North China via Yellow River valley and its tributary valleys in the Northeastern Tibetan Plateau (NETP). This migration is constituted of four stages (Upper Paleolithic, Epi-Paleolithic, Neolithic and Bronze Age) when human adapted to the high altitude environment and climate change with different strategies and techniques. Particularly, the prevail of microlithic technology in North China provoked hunter-gatherers' first visit to the NETP in relatively ameliorated last Deglacial period, and the the quick development of millet farming and subsequent mixed barley-wheat farming and sheep herding facilitated farmers and herders permanently settled in Tibetan Plateau, even above 3000 masl, during mid- and late Holocene. References: Chen et al., 2015. Agriculture facilitated permanent human occupation of the Tibetan Plateau after 3600 BP. Science, 347: 248-250. Meyer et al., 2016

  11. Compressive Tectonics around Tibetan Plateau Edges

    Institute of Scientific and Technical Information of China (English)

    Zhao Zhixin; Xu Jiren

    2009-01-01

    Various earthquake fault types, mechanism solutions, stress field, and other geophysical data were analyzed for study on the crust movement in the Tibetan plateau and its tectonic implications. The results show that numbers of thrust fault and strike-slip fault type earthquakes with strong compressive stress near NNE-SSW direction occurred in the edges around the plateau except the eastern boundary. Some normal faulting type earthquakes concentrate in the Central Tibetan plateau. The strikes of fault planes of thrust and strike-slip faulting earthquakes are almost in the E-W direction based on the analyses of the Wulff stereonet diagrams of fault plane solutions. This implies that the dislocation slip vectors of the thrust and strike-slip faulting type events have quite great components in the N-S direction. The compression motion mainly probably plays the tectonic active regime around the plateau edges. The compressive stress in N-S or NE-SW directions predominates earthquake occurrence in the thrust and strike-slip faulting event region around the plateau. The compressive motion around the Tibetan plateau edge is attributable to the northward motion of the Indian subcontinent plate. The northward motion of the Tibetan plateau shortened in the N-S direction encounters probably strong obstructions at the western and northern margins.

  12. Constructions of new plateaued functions from known ones

    Institute of Scientific and Technical Information of China (English)

    Zhang Weiguo; Ding Yong; Zhang Ning; Xiao Guozhen

    2008-01-01

    A number of methods for constructing new plateaued functions from known ones are presented. By properly combining the known plateaued functions it is possible to get highly nonlinear resilient plateaued functions. The order, resiliency and propagation characteristics of the constructed plateaued functions are discussed. We show the new functions could possess the desirable cryptographic property.

  13. Argalis on the Qinghai-Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The argali are listed by the State as animals subject tosecond-class protection,and no killing is allowed. The international communitylists argali on the Qinghai-Tibet Plateau as animals that must not be hunted.

  14. Colorado Plateau Rapid Ecoregion Assessment Data Catalog

    Data.gov (United States)

    Bureau of Land Management, Department of the Interior — Datasets used in the analysis of the Colorado Plateau (COP) Rapid Ecoregion Assessment (REA).They can be downloaded via a layer package (lpk, similar to a zip file...

  15. First description of the nymph and larva of Dermacentor raskemensis (Acari: Ixodidae), parasites of pikas and other small mammals in Central Asia.

    Science.gov (United States)

    Apanaskevich, Dmitry A

    2013-09-01

    Dermacentor raskemensis Pomerantzev, 1946 is one of the rare Asian species in this genus. The immature stages of this species have never been described. Reexamination of D. raskemensis holdings stored in the United States National Tick Collection revealed a collection lot containing reared nymphs and larvae of this species. This collection made it possible for us to find numerous nymphs and larvae of D. raskemensis among previously unidentified material collected in the field. Both immature stages of D. raskemensis are described here for the first time. Nymphs of D. raskemensis can be distinguished from those of other Dermacentor species in the region by small spiracular plate, relatively short and obtuse lateral projections of basis capituli dorsally, relatively short spurs on coxa I and the internal spur is characteristically very broadly rounded at its apex, and very small spur on coxa IV, whereas larvae of D. raskemensis can be distinguished from other Dermacentor by relatively short and obtuse lateral projections of basis capituli, approximately 6 denticles in the median files on hypostome, and relatively short, broad, and rounded spur on coxa I. The nymphs and larvae of D. raskemensis studied originate from Afghanistan, India, Iran, and Pakistan, where they were collected from pikas and other small mammals.

  16. Pyramid Schemes on the Tibetan Plateau

    OpenAIRE

    Devin Gonier; Rgyal yum sgrol ma

    2012-01-01

    The unique features of pyramid schemes and certain underlying causes for their development on the Tibetan Plateau are analyzed. Research was conducted by analyzing 521 surveys, allowing estimation of pyramid scheme activity on the Plateau and an identification of related cultural and social specificities. Firsthand accounts were collected revealing details of personal involvement. Survey data and similarities in the accounts were studied to suggest how involvement in pyramid schemes might be ...

  17. The Hikurangi Plateau: Tectonic Ricochet and Accretion

    Science.gov (United States)

    Willis, David; Moresi, Louis; Betts, Peter; Whittaker, Joanne

    2015-04-01

    80 million years between interactions with different subduction systems provided time for the Hikurangi Plateau and Pacific Ocean lithosphere to cool, densify and strengthen. Neogene subduction of the Hikurangi Plateau occurring orthogonal to its Cretaceous predecessor, provides a unique opportunity to explore how changes to the physical properties of oceanic lithosphere affect subduction dynamics. We used Underworld to build mechanically consistent collision models to understand the dynamics of the two Hikurangi collisions. The Hikurangi Plateau is a ~112 Ma, 15km thick oceanic plateau that has been entrained by subduction zones immediately preceding the final break-up of Eastern Gondwana and currently within the active Hikurangi Margin. We explore why attempted subduction of the plateau has resulted in vastly different dynamics on two separate occasions. Slab break-off occured during the collision with Gondwana, currently there is apparent subduction of the plateau underneath New Zealand. At ~100Ma the young, hot Hikurangi Plateau, positively buoyant with respect to the underlying mantle, impacted a Gondwana Margin under rapid extension after the subduction of an mid-ocean ridge 10-15Ma earlier. Modelling of plateaus within young oceanic crust indicates that subduction of the thickened crust was unlikely to occur. Frontal accretion of the plateau and accompanying slab break-off is expected to have occured rapidly after its arrival. The weak, young slab was susceptible to lateral propagation of the ~1500 km window opened by the collision, and break-off would have progressed along the subduction zone inhibiting the "step-back" of the trench seen in older plates. Slab break-off coincided with a world-wide reorganisation of plate velocites, and orogenic collapse along the Gondwana margin characterised by rapid extension and thinning of the over-riding continental plate from ~60 to 30km. Following extension, Zealandia migrated to the NW until the Miocene allowing the

  18. Optical Turbulence above the Internal Antarctic Plateau

    CERN Document Server

    Masciadri, E; Hagelin, S; Moigne, P Le; Noilhan, J

    2010-01-01

    The internal antarctic plateau revealed in the last years to be a site with interesting potentialities for the astronomical applications due to the extreme dryness and low temperatures, the typical high altitude of the plateau, the weak level of turbulence in the free atmosphere down to a just few tens of meters from the ground and the thin optical turbulence layer developed at the ground. The main goal of a site testing assessment above the internal antarctic plateau is to characterize the site (optical turbulence and classical meteorological parameters) and to quantify which is the gain we might obtain with respect to equivalent astronomical observations done above mid-latitude sites to support plans for future astronomical facilities. Our group is involved, since a few years, in studies related to the assessment of this site for astronomical applications that include the characterization of the meteorological parameters and optical turbulence provided by general circulation models as well as mesoscale atmo...

  19. Tectonomagmatic Associations on the Central Andean Plateau

    Science.gov (United States)

    de Silva, S. L.; Viramonte, J. G.

    2012-12-01

    The Neogene evolution of the Central Andes is characterized by a strong association between plate convergence, mountain building and plateau formation, and magmatism. Plateau uplift by crustal shortening and thickening in the lower crust is broadly coincident with large scale silicic magmatism defined by the Neogene Central Andean ignimbrite province. Of particular interest here are the spatiotemporal correlations between silicic magmatism and tectonic evolution of the Altiplano-Puna plateau. Although magmatism is driven by the subduction-related flux from mantle to crust, the shift to "crustal" magmatism as indicated by elevated crustal isotopic indices after ~10Ma suggests a link between crustal thickening, plateau formation and silicic magmatism. In particular, elevated geotherms associated with crustal thickening and enhanced mantle flux associated with lithospheric delamination may have played a role in thermally preparing the Central Andean crust for enhanced silicic magma production during the extensive Neogene ignimbrite flare-up. Emplacement of these magmas in the upper crust throughout the Neogene may have fuelled a period of significant interaction between magmatism and tectonism on the plateau. With particular reference to the 21° to 24°S segment of the Central Andes, spatial and structural coincidence of calderas of the Altiplano Puna Volcanic Complex with the NW-SE striking Calama-Olacapata-El Toro fault zone suggests significant tectonomagmatic interaction. Location of calderas suggest that these regional faults focused magma intrusion and storage, while spatially and temporally correlated eruption pulses connote a tectonic control. Indeed, current thermomechanical models of magma chamber development and eruption triggering promote a role for external triggering of "perched" upper crustal magma chambers. This might have been achieved by melt-enhanced deformation, or alternatively, significant uplift (~1km) associated with the development of large

  20. Peopling the Tibetan plateau: insights from archaeology.

    Science.gov (United States)

    Aldenderfer, Mark

    2011-01-01

    Recent studies of the genome of modern Tibetans have revealed the existence of genes thought to provide an adaptive advantage for life at high elevation. Extrapolating from this discovery, some researchers now argue that a Tibetan-Han split occurred no more than 2750 yr ago. This date is implausible, and in this paper I review the archaeological data from the Tibetan plateau as one means by which to examine the veracity of this assertion. Following a review of the general state of knowledge of Tibetan prehistory, which is unfortunately only at its beginnings, I first examine the data that speak to the initial peopling of the plateau and assess the evidence that traces of their presence can be seen in modern Tibetans today. Although the data are sparse, both archaeology and genetics suggest that the plateau was occupied in the Late Pleistocene, perhaps as early as 30,000 yr ago, and that these early peoples have left a genetic signature in modern Tibetans. I then turn to the evidence for later migrations and focus on the question of the timing of the establishment of permanent settled villages on the plateau. Three areas of the plateau-northeastern Qinghai, extreme eastern Tibet, and the Yarlung Tsangpo valley-have evidence of permanent settlements dating from ca. 6500, 5900, and 3750 yr ago, respectively. These data are not consonant with the 2750 yr ago date for the split and suggest at a minimum that the plateau has been occupied substantially longer and, further, that multiple migrations at different times and from different places have created a complex mosaic of population history. © Mary Ann Liebert, Inc.

  1. Plateau-insulator transition in graphene

    Energy Technology Data Exchange (ETDEWEB)

    Amado, M; Diez, E; Caridad, J M [Laboratorio de Bajas Temperaturas, Universidad de Salamanca, E-37008 Salamanca (Spain); Lopez-Romero, D [CT-ISOM, Universidad Politecnica de Madrid, E-28040 Madrid (Spain); Rossella, F; Dionigi, F; Bellani, V [Dipartimento di Fisica ' A Volta' and CNISM, Universita degli studi di Pavia, I-27100 Pavia (Italy); Maude, D K, E-mail: marioam@fis.ucm.e [Laboratoire National des Champs Magnetiques Intenses, F-38042 Grenoble (France)

    2010-05-15

    We investigate the quantum Hall effect (QHE) in a graphene sample with Hall-bar geometry close to the Dirac point at high magnetic fields up to 28 T. We have discovered a plateau-insulator quantum phase transition passing from the last plateau for the integer QHE in graphene to an insulator regime {nu}=-2{yields}{nu}=0. The analysis of the temperature dependence of the longitudinal resistance gives a value for the critical exponent associated with the transition equal to {kappa}=0.58{+-}0.03.

  2. The Influence of Red Fox′s Odor on the Reproduction of the Plateau Pika%赤狐气味对高原鼠兔繁殖的影响

    Institute of Scientific and Technical Information of China (English)

    魏万红; 曹伊凡; 张堰铭; 殷宝法; 王金龙

    2004-01-01

    在野外条件下,利用赤狐的粪尿气味增加高原鼠兔的捕食风险,研究捕食风险对高原鼠兔繁殖的影响.结果表明,作为衡量高原鼠兔繁殖投入大小的定量指标,成体高原鼠兔的体重变化在捕食风险处理样方与对照样方之间没有明显的不同,随着繁殖期的延长,两样方内雌雄个体的体重均显著减少,说明捕食风险对高原鼠兔的繁殖投入无明显影响,因此,捕食风险对幼体的生长、发育也无明显的作用.捕食风险增加后,高原鼠兔平均每个雌性成体拥有的后代数目、性比和居留率与对照样方比较均无明显不同,但是由于扩散等原因使每个雄性成体拥有的后代数、繁殖期结束后幼体的性比有明显的差异.以上结果并未显示出捕食者气味作为捕食风险对高原鼠兔的繁殖产生抑制作用,其主要原因是捕食风险的类型不同和研究期间高原鼠兔本身承受的捕食风险较大,高原鼠兔可能通过行为变化调节捕食风险增加对其产生的不利影响.

  3. Sino-Japanese Teamwork Probes Environment Changes on Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ With the support of a CAS project on Holocene environmental changes and their influences on the ecosystem of the Tibetan Plateau, a research group headed by Prof. Zhu Liping from the CAS Institute of Tibetan Plateau Research and their Japanese collaborators carried out a field survey in Puma Yumco area on the Tibetan Plateau from September 8 to 20.

  4. The Hubble Flow of Plateau Inflation

    NARCIS (Netherlands)

    Coone, Dries; Roest, Diederik; Vennin, Vincent

    2015-01-01

    In the absence of CMB precision measurements, a Taylor expansion has often been invoked to parametrize the Hubble flow function during inflation. The standard "horizon flow" procedure implicitly relies on this assumption. However, the recent Planck results indicate a strong preference for plateau

  5. The Hubble Flow of Plateau Inflation

    NARCIS (Netherlands)

    Coone, Dries; Roest, Diederik; Vennin, Vincent

    2015-01-01

    In the absence of CMB precision measurements, a Taylor expansion has often been invoked to parametrize the Hubble flow function during inflation. The standard "horizon flow" procedure implicitly relies on this assumption. However, the recent Planck results indicate a strong preference for plateau in

  6. Ozone Minihole Found over Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Through a comprehensive analysis, researchers from the CAS Institute of Atmospheric Physics (IAP) discovered an ozone minihole, a large area with the lowest total ozone column (TOC, see figure), over the Qinghai-Tibet Plateau from Dec. 14 to 17, 2003.

  7. Construction of plateaued functions satisfying multiple criteria

    Institute of Scientific and Technical Information of China (English)

    Zhang Weiguo

    2005-01-01

    A class of plateaued functions has been got by using the Maiorana-McFarland construction. A variety of desirable criteria for functions with cryptographic application could be satisfied: balancedness, high nonlinearity, correlation immunity of reasonably high order, strict avalanche criterion, non-existence of non-zero linear structures, good global avalanche characteristics, etc.

  8. Planation Surfaces on the Tibet Plateau, China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A planation hypothesis is proposed to explain landform evolution of the Tibet Plateau. A denudation threshold (T), the maximum potential denudation rate for a certain type of rock, is introduced to explain the combined effects of lithology and tectonics on landform evolution. If the tectonic uplifting rate (U) is equal to or less than the threshold rate (U ≤ T), the tectonic uplifting and terrain denudation are in dynamic equilibrium, and landforms are in a steady state. The end product should be planation surfaces whether the original landforms are fiat plains or deeply dissected mountains. If U > T, uplift and denudation are not able to reach a dynamic equilibrium state. The plateau surface is mostly underlain by soft rocks, such as the Mesozoic epimetamorphic argillites and Tertiary sedimentary rocks, while the mountain ranges comprise hard rocks, such as granite, gneiss and limestone. In soft rock regions, hills are low with a relative relief of mostly less than 100m and the slopes are gentle at a gradient of <200. In contrast, hills can maintain steep slopes in hard rock regions. The Tibet Plateau has been under an equilibrium condition between tectonic uplifting and denudation except for the mountain ranges. The plateau might have reached the present altitudes before the Quaternary.

  9. Soil erosion and management on the Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The Loess Plateau is well known to the world for its intense soil erosion. The root cause for river sedimentation of Yellow River (Huanghe) and its resultant "hanging river" in certain section is soil and water loss on the Loess Plateau. The Loess Plateau has a long cultivation history, hence population growth, vegetation degeneration and plugging constitute the chief reason for serious soil and water loss on Loess Plateau. This paper analyses several successful cases and failures in soil conservation, presents practical soil conservation technique and related benefit analysis, and discusses some effective methods adopted in China in soil erosion control, research directions and future perspectives on Loess Plateau.

  10. Hydrogeology of the Markagunt Plateau, Southwestern Utah

    Science.gov (United States)

    Spangler, Lawrence E.

    2010-01-01

    The Markagunt Plateau, in southwestern Utah, lies at an altitude of about 9,500 feet and is capped primarily by Quaternary-age basalt that overlies Eocene-age freshwater limestone of the Claron Formation. Over large parts of the Markagunt Plateau, dissolution of the Claron limestone and subsequent collapse of the overlying basalt have produced a terrain characterized by sinkholes as much as 1,000 feet across and 100 feet deep. Numerous large springs discharge from the basalt and underlying limestone on the plateau, including Mammoth Spring, one of the largest springs in Utah, with a discharge that can exceed 300 cubic feet per second. Discharge from Mammoth Spring is from the Claron Formation; however, recharge to the spring largely takes place by both focused and diffuse infiltration through the basalt that caps the limestone. Results of dye tracing to Mammoth Spring indicate that recharge originates largely southwest of the spring outside of the Mammoth Creek watershed, as well as from losing reaches along Mammoth Creek. Maximum groundwater travel time to the spring from dye-tracer tests during the snowmelt runoff period was about 1 week. Specific conductance and water temperature data from the spring show an inverse relation to discharge during snowmelt runoff and rainfall events, also indicating short groundwater residence times. Results of major-ion analyses for samples collected from Mammoth and other springs on the plateau indicate calcium-bicarbonate type water containing low (less than 200 mg/L) dissolved-solids concentrations. Investigations in the Navajo Lake area along the southern margin of the plateau have shown that water losing to sinkholes bifurcates and discharges to both Cascade and Duck Creek Springs, which subsequently flow into the Virgin and Sevier River basins, respectively. Groundwater travel times to these springs, on the basis of dye tracing, were about 8.5 and 53 hours, respectively. Similarly, groundwater travel time from Duck Creek

  11. Vulnerability on the Roof of the World: Resilience to Climate Change and Natural Resource Policies on the Tibetan Plateau

    Science.gov (United States)

    Klein, J. A.; Hopping, K. A.; Yeh, E.; Hu, J.; Nyima, Y.; Boone, R.; Galvin, K.; Kang, S.; Ojima, D. S.

    2010-12-01

    Pastoralists on the Tibetan Plateau are a marginalized people living in an extreme environment and may be especially vulnerable as the system approaches critical thresholds. In Tibet, temperatures are increasing several times more than the global average while the frequency and severity of severe snowstorms is predicted to increase. Pastoralists are also experiencing reduced mobility and severe grazing restrictions. We are using interdisciplinary frameworks and methods that include a multifactor ecological experiment, household interviews, remote sensing, and a coupled ecosystem and household decision-making model to examine herder and ecosystem vulnerability to climate change and extreme weather events within the context of changing natural resource policies in China. The fully factorial ecological experiment includes two climate changes (warming and spring snow additions) and two types of grazing (yak and pika). We established the experiment in 2008 within the Tibet Autonomous Region (4,870 m) and are monitoring microclimate, vegetation, nutrient availability, carbon fluxes and stable isotopes. We are investigating the sensitivity of the system, whether it is likely to cross critical thresholds, and how resilient this system may be to predicted climate and land use changes. Semi-structured interviews on indigenous knowledge and vulnerability complement the ecological experimental work. We are asking herders about climatic and ecological change and vulnerability to snow disasters. To integrate our ecological and social findings, we are coupling an ecosystem model to an agent-based pastoral household model. Our results from the experiment and the indigenous knowledge study suggest that Kobresia pygmaea, the dominant species and primary grazing resource, is vulnerable to warming. Snow additions can partially mediate this effect. Herders throughout this region share common knowledge about both climatic and ecological changes, but appear to be more closely attuned to

  12. Magnetotelluric sounding results in eastern Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    马晓冰; 孔祥儒; 刘宏兵; 闫永利

    2001-01-01

    The results of Zayu-Qingshuihe MT sounding profile carried out in eastern Tibetan Plateau are presented in this paper. Using 2-D RRI method, the resistivity distribution with depth is obtained along the profile. It is featured by the resistivity zones in the horizontal direction and layers in the vertical direction. The Bangong-Nujiang suture zone and Jinshajiang suture zone are both important electrical conductivity-separating zones in the plateau, and the former is a zone with relatively low resistivity while the latter is an electrical conductivity gradient zone. The highly electrical conductive bodies in the mid and lower crust of northern Qiangtang and Bayan Har Terrain might be caused by regional melting due to shear heating during the process of subduction in tectonic evolution.

  13. The crustal composition of the Falkland Plateau

    Science.gov (United States)

    Klemt, Claudia; Jokat, Wilfried

    2015-04-01

    The Falkland Islands are situated in the South Atlantic Ocean 500 km east of Patagonia, South America. The islands are part of the Falkland Plateau, which stretches eastward for more than 1500 km. A bathymetric high, the Maurice Ewing Bank, terminates the plateau in the east. Until Late Jurassic the Falkland Islands were part of Gondwana and were located adjacent to the east coast of South Africa. While the Falkland Islands and Maurice Ewing Bank are proved to be of continental composition, the nature and structure of the Falkland Plateau's basement in between is debatable. The first crustal model derived from sonobuoy data contradicts an only recently published 3D-gravity model. To enhance the understanding of Gondwana break-up considering timing, geometry and amount of volcanism, further knowledge about the structure and thickness of the crust is inevitable. During the ANT-XXIX/5 Polarstern cruise seismic refraction measurements were conducted using Ocean Bottom Seismometers (OBS) and Reftek land stations onshore of East Falkland. The OBS were deployed at 78 locations along an approximately 1500 km east-west stretching profile. For the western transect a P-wave velocity model is calculated using 2D-raytracing techniques. The results are presented in combination with potential field data showing the extension of the Falkland Islands basement, the continent-ocean transition zone and the crustal structure of the plateau. On the Falkland Plateau Basin sediment thickness is about 6 km with velocities ranging from 1.7 to 4.1 km/s in the upper part and about 4.7 km/s above basement. The crust is of oceanic composition with an igneous section that is considerably thicker than average oceanic crust (up to 17 km). The velocity structure in the upper crustal part is typical for layer 2 with a velocity gradient ranging from 5.4 km/s to 6.5 km/s and thicknesses between 1.5 km and 4 km. Layer 3 is about 14 km thick with a velocity gradient from 6.6 km/s to 7.6 km/s, which is

  14. Chemical erosion and hydrologic budget for the Susure karst plateau

    Directory of Open Access Journals (Sweden)

    Nikić Zoran

    2010-01-01

    Full Text Available The karst plateau of Susure, about 4.5 km2 in surface area, is situated on the Jadovnik eastern offset, western Serbia. The plateau is a morphologic unit higher 15 m to 30 m than the surrounding terrain. The unit consists of crushed and karstified Middle Triassic limestones. Numerous hydrogeological and geomorphologic features of the plateau are attractive for visitors in this economically underdeveloped country. Rocks building up the surrounding terrain are largely peridotites. Surface streams flow neither into nor off the plateau. Atmospheric precipitations discharge to evapotanspiration and filtration underground. More than eighteen constant springs at the limestone/peridotite tectonic contact drain fracture aquifers on the karst plateau border. Measured precipitations and springflows were the input and output data for accounting water budget of an aquifer of Middle Triassic limestones in the Susure plateau.

  15. Colorado Plateau magmatism and uplift by warming of heterogeneous lithosphere.

    Science.gov (United States)

    Roy, Mousumi; Jordan, Thomas H; Pederson, Joel

    2009-06-18

    The forces that drove rock uplift of the low-relief, high-elevation, tectonically stable Colorado Plateau are the subject of long-standing debate. While the adjacent Basin and Range province and Rio Grande rift province underwent Cenozoic shortening followed by extension, the plateau experienced approximately 2 km of rock uplift without significant internal deformation. Here we propose that warming of the thicker, more iron-depleted Colorado Plateau lithosphere over 35-40 Myr following mid-Cenozoic removal of the Farallon plate from beneath North America is the primary mechanism driving rock uplift. In our model, conductive re-equilibration not only explains the rock uplift of the plateau, but also provides a robust geodynamic interpretation of observed contrasts between the Colorado Plateau margins and the plateau interior. In particular, the model matches the encroachment of Cenozoic magmatism from the margins towards the plateau interior at rates of 3-6 km Myr(-1) and is consistent with lower seismic velocities and more negative Bouguer gravity at the margins than in the plateau interior. We suggest that warming of heterogeneous lithosphere is a powerful mechanism for driving epeirogenic rock uplift of the Colorado Plateau and may be of general importance in plate-interior settings.

  16. Observational Facts of Sustained Departure Plateau Vortexes

    Institute of Scientific and Technical Information of China (English)

    YU Shuhua; GAO Wenliang; PENG Jun; XIAO Yuhua

    2014-01-01

    By using the twice-daily atmospheric observation data from 1998 to 2012, station rainfall data, Tropical Rainfall Measure Mission (TRMM) data, as well as the plateau vortex and shear line year book, charac-teristics of the sustained departure plateau vortexes (SDPVs) are analyzed. Some new useful observational facts and understanding are obtained about the SDPV activities. The following results are obtained. (1) The active period of SDPVs is from June to August, most in July, unlike that of the unsustained depar-ture plateau vortexes (UDPVs), which have same occurrence frequencies in the three summer months. (2) The SDPVs, generated mainly in the Qumalai neighborhood and situated in a sheared surrounding, move eastward or northeastward, while the UDPVs are mainly led by the upper-level trough, and move eastward or southeastward. (3) The SDPVs influence wide areas of China, even far to the Korean Peninsula, Japan, and Vietnam. (4) The SDPVs change their intensities and properties on the way to the east. Most of them become stronger and produce downpour or sustained regional rainstorms to the south of Yellow River. (5) The longer the SDPV sustains, the more baroclinity it has. (6) When an SDPV moves into the sea, its central pressure descends and rainfall increases in all probability. (7) An SDPV might spin over the bend of the Yellow River when there exists a tropical cyclone in the East China Sea. It could also move oppositely to a landed tropical low pressure originated from the sea to the east of Taiwan or from the South China Sea.

  17. The Manihiki Plateau, Hikurangi Plateau, Wishbone Scarp, and Osbourn Trough: A Review and Analysis

    Science.gov (United States)

    Henig, A.; Luyendyk, B. P.

    2007-12-01

    The extinct Osbourn Trough spreading system in the southwestern Pacific played a key role in separating the once joined Hikurangi and Manihiki Plateaus in Cretaceous time. Recent studies by Downey et al. [2007] and Taylor [20006] have provided new data and concepts on that history. Studies by Larson et al. [2002] describe Cretaceous histories adjacent and east of the Osbourn system and Eagles et al. [2004] describe a history for the southwest Pacific just after the Osbourn system became extinct. The lack of identifiable magnetic anomalies allows tectonic events during separation of the plateaus and spreading on the Osbourn Trough to occur between about 124.6 and 84 Ma (Chron 34). Satellite gravity maps of the region identify what are interpreted as Cretaceous fracture zone trends. Swath bathymetry data reveal at least four provinces of abyssal hill trends. What is known are the following: Minimum age of the Manihiki High Plateau at 123.4 Ma from DSDP Site 317, the age of seafloor, 115 Ma, from a dredge sample from the southern segment of the West Wishbone Scarp 300 km northeast of the Hikurangi Plateau, the east-west trend and extent of the extinct Osbourn spreading center at latitude 26° S, the trends (NNE-SSW to NE-SW) and extent of portions of the West Wishbone Scarp east of the Hikurangi Plateau, the N-S trend of the East Wishbone Scarp that appears to truncate the West Wishbone Scarp, the NNE- SSW trend and extent of the prominent Manihiki (Eastern) Scarp at the eastern boundary of the Manihiki High Plateau, the NW-SE trend and extent of the Rapuhia Scarp on the northwestern Hikurangi Plateau, and trends in abyssal hills; E-W near the Osbourn Trough and WNW-ESE closer to the plateaus. Differences in abyssal hill morphology suggest one or more changes in spreading rates. The Osbourn Trough began rifting apart a Large Igneous Province formed at 123.5 +/- 1.5 Ma, into the separate Ontong-Java, Manihiki, and Hikurangi Plateaus by 121 Ma. After an initial 6 Myr

  18. Plateau Waves of Intracranial Pressure and Multimodal Brain Monitoring.

    Science.gov (United States)

    Dias, Celeste; Maia, Isabel; Cerejo, Antonio; Smielewski, Peter; Paiva, José-Artur; Czosnyka, Marek

    2016-01-01

    The aim of this study was to describe multimodal brain monitoring characteristics during plateau waves of intracranial pressure (ICP) in patients with head injury, using ICM+ software for continuous recording. Plateau waves consist of an abrupt elevation of ICP above 40 mmHg for 5-20 min. This is a prospective observational study of patients with head injury who were admitted to a neurocritical care unit and who developed plateau waves. We analyzed 59 plateau waves that occurred in 8 of 18 patients (44 %). At the top of plateau waves arterial blood pressure remained almost constant, but cerebral perfusion pressure, cerebral blood flow, brain tissue oxygenation, and cerebral oximetry decreased. After plateau waves, patients with a previously better autoregulation status developed hyperemia, demonstrated by an increase in cerebral blood flow and brain oxygenation. Pressure and oxygen cerebrovascular reactivity indexes (pressure reactivity index and ORxshort) increased significantly during the plateau wave as a sign of disruption of autoregulation. Bedside multimodal brain monitoring is important to characterize increases in ICP and give differential diagnoses of plateau waves, as management of this phenomenon differs from that of regular ICP.

  19. Interpretation of Plateau in High-Harmonic Generation

    Institute of Scientific and Technical Information of China (English)

    程太旺; 李晓峰; 敖淑艳; 傅盘铭

    2003-01-01

    The plateau in high-harmonic generation is investigated in the frequency domain. Probability density of an electron in an electromagnetic field is obtained through analysing the quantized-field Volkov state. The plateau of high-harmonic generation reflects the spectral density of the electron at the location of nucleus after abovethreshold ionization.

  20. Parhelic-like circle from light scattering in Plateau borders

    Energy Technology Data Exchange (ETDEWEB)

    Tufaile, A., E-mail: tufaile@usp.br; Tufaile, A.P.B.

    2015-03-06

    We are reporting a new simple optical element to generate halos. We have observed interesting patterns of light scattering in Plateau borders in foams. In analogy to the atmospheric phenomena known as parhelic circle, sun dogs, and sun pillars, we have named the features of the patterns observed as parlaseric circle, laser dogs, and laser pillars. The triangular symmetry of the Plateau borders is analogous to the hexagonal symmetry of ice crystals which produce these atmospheric phenomena. Working with one Plateau border at a time, we have observed wave optics phenomena that are not perceived in the atmospheric phenomena, such as diffraction and interference. - Highlights: • We obtained halo formation from light scattering in a Plateau border using an experiment. • We explained halo formation using geometrical theory of diffraction. • An optical element based on a Plateau border is proposed. • We compared some aspects of the parhelic circle with the parlaseric circle.

  1. Extension of the Yellowstone plateau, eastern Snake River Plain, and Owyhee plateau

    Science.gov (United States)

    Rodgers, David W.; Hackett, William R.; Ore, H. Thomas

    1990-11-01

    Formation of the late Cenozoic volcanic province comprising the Owyhee plateau, eastern Snake River Plain, and Yellowstone plateau has been accompanied by east-northeast-directed crustal extension. A new vector of 45 mm/yr, N56°E for the migration of silicic volcanism across the volcanic province is calculated. If migration of volcanism reflects west-southwest continental drift over a mantle plume, a zone of crustal extension must separate the volcanic province from the more slowly moving North American craton. Space-time relations of basin fill in the adjacent Basin and Range province provide evidence for a zone of extension, about 125 km wide, coincident with and east of coeval silicic volcanism. Since 16 Ma, the zone of extension has migrated along with silicic volcanism, maintaining its position between the province and the unextended craton.

  2. Deep structure of the Iceland plateau

    Energy Technology Data Exchange (ETDEWEB)

    Evans, J.R.; Sacks, I.S.

    1979-11-10

    The topography of the sea floor between Iceland and Jan Mayen Island is flat and elevated in relation to most ocean basins. Marine geophysical observations in the area have shown that it was formed by sea floor spreading but have not revealed details of structures more than a few hundred meters beneath the sea floor. We have examined the dispersion of seismic surface waves across the Iceland Plateau and have modeled structures to depths of up to 100 km. We find that the thickness of the crustal component of the lithosphere is much greater than that of normal oceanic structures, perhaps exceeding 20 km. We suggest that the elevation of the region is due to isostatic compensation for this excess of low-density crustal material. The total lithospheric thickness is about 50 km throughout the region, indicating that the lithosphere thickens with age at a rate similar to that found in other young oceans.

  3. Plateau inflation in SUGRA-MSSM

    Science.gov (United States)

    Chakravarty, Girish Kumar; Gupta, Gaveshna; Lambiase, Gaetano; Mohanty, Subhendra

    2016-09-01

    We explored a Higgs inflationary scenario in the SUGRA embedding of the MSSM in Einstein frame where the inflaton is contained in the SU (2) Higgs doublet. We include all higher order non-renormalizable terms to the MSSM superpotential and an appropriate Kähler potential which can provide slow-roll inflaton potential in the D-flat direction. In this model, a plateau-like inflation potential can be obtained if the imaginary part of the neutral Higgs acts as the inflaton. The inflationary predictions of this model are consistent with the latest CMB observations. The model represents a successful Higgs inflation scenario in the context of Supergravity and it is compatible with Minimal Supersymmetric extension of the Standard Model.

  4. Plateau inflation in SUGRA-MSSM

    Directory of Open Access Journals (Sweden)

    Girish Kumar Chakravarty

    2016-09-01

    Full Text Available We explored a Higgs inflationary scenario in the SUGRA embedding of the MSSM in Einstein frame where the inflaton is contained in the SU(2 Higgs doublet. We include all higher order non-renormalizable terms to the MSSM superpotential and an appropriate Kähler potential which can provide slow-roll inflaton potential in the D-flat direction. In this model, a plateau-like inflation potential can be obtained if the imaginary part of the neutral Higgs acts as the inflaton. The inflationary predictions of this model are consistent with the latest CMB observations. The model represents a successful Higgs inflation scenario in the context of Supergravity and it is compatible with Minimal Supersymmetric extension of the Standard Model.

  5. Have Periprosthetic Hip Infection Rates Plateaued?

    Science.gov (United States)

    Perfetti, Dean C; Boylan, Matthew R; Naziri, Qais; Paulino, Carl B; Kurtz, Steven M; Mont, Michael A

    2017-07-01

    Periprosthetic joint infection (PJI) is a serious complication of total hip arthroplasty (THA). Although the number of revision cases is increasing, the prevalence of PJI as an indication for revision surgery, and the variability of this indication among surgeons and hospitals, is unclear. The New York Statewide Planning and Research Cooperative System was used to identify 33,582 patients undergoing revision THA between 2000 and 2013. PJI was identified using International Classification of Diseases, Ninth Revision diagnosis codes. Volume was defined using mean number of revision THAs performed annually by each hospital and surgeon. PJI was the indication for 13.0% of all revision THAs. The percentage of revision THAs for PJI increased between years 2000 and 2007 (odds ratio [OR] = 1.05, P < .001), but decreased between years 2008 and 2013 (OR = 0.96, P = .001). Compared to medium-volume hospitals, the PJI burden at high-volume hospitals decreased during years 2000-2007 (OR = 0.58, P < .001) and 2008-2013 (OR = 0.57, P < .001). Compared to medium-volume surgeons, the PJI burden for high-volume surgeons increased during years 2000-2007 (OR = 1.39, P < .001), but did not differ during years 2008-2013 (P = .618). The burden of PJI as an indication for revision THA may be plateauing. High-volume institutions have seen decreases in the percentage of revisions performed for PJI over the complete study duration. Specific surgeon may be associated with the plateauing in PJI rates as high-volume surgeons in 2008-2013 were no longer found to be at increased risk of PJI as an indication for revision THA. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. 阿尔金山国家级自然保护区食肉鸟兽调查%Survey on Carnivore Birds and Mammals in Altun Mountain National Natural Reserve

    Institute of Scientific and Technical Information of China (English)

    李叶; 张翔; 时磊

    2012-01-01

    2011-2012年,对阿尔金山国家级自然保护区的鼠类天敌——食肉鸟兽开展专项调查.通过调查,初步查明了保护区内共分布有鼠类天敌27种,分属2纲3目7科17属,其中有国家一级保护动物5种,二级保护动物17种.赤狐为保护区首次记录物种.对主要天敌的种类、分布、食性和活动规律,以及对高原鼠兔防治的潜在作用进行了初步分析.藏狐和大鵟可以作为进一步开展天敌防治鼠害工作的目标物种.%A special investigation on carnivorous mammals and birds was carried out in the Altun Mountain National Nature Reserve in 2011-2012. Research found out total 27 kinds of predators on rodent pests belonging to 2 classes,3 orders,7 families,and 17 genera distributing in the protected areas. Among them there are 5 kinds of national first class protection animal and 17 kinds of national second class protection animal. The red fox(Vulpes vuLpes)was first recorded from this region. The first analysis was carried out on varieties,distribution,feeding habits and the patterns of the main natural enemies and the potential role in controlling plateau pika (Ochotona curzoniae) . Tibetan fox and Buzzard can be used as target species for a further natural enemies controlling pika project.

  7. Total knee arthroplasty and fractures of the tibial plateau

    Science.gov (United States)

    Softness, Kenneth A; Murray, Ryan S; Evans, Brian G

    2017-01-01

    Tibial plateau fractures are common injuries that occur in a bimodal age distribution. While there are various treatment options for displaced tibial plateau fractures, the standard of care is open reduction and internal fixation (ORIF). In physiologically young patients with higher demand and better bone quality, ORIF is the preferred method of treating these fractures. However, future total knee arthroplasty (TKA) is a consideration in these patients as post-traumatic osteoarthritis is a common long-term complication of tibial plateau fractures. In older, lower demand patients, ORIF is potentially less favorable for a variety of reasons, namely fixation failure and the need for delayed weight bearing. In some of these patients, TKA can be considered as primary mode of treatment. This paper will review the literature surrounding TKA as both primary treatment and as a salvage measure in patients with fractures of the tibial plateau. The outcomes, complications, techniques and surgical challenges are also discussed.

  8. Phylogeography of regional fauna on the Tibetan Plateau: A review

    Institute of Scientific and Technical Information of China (English)

    Shujuan Yang; Hailiang Dong; Fumin Lei

    2009-01-01

    The studies of uplift and glaciations of the Tibetan Plateau are summarized, and a series of recent case studies of the endemic species based on DNA sequences are detailed. In general, these molecular data show that all the organisms originated from Early Pliocene to Late Miocene, and then multi-stages of divergence/speciation occurred within each taxa following their original occupation on the pla-teau, mainly as a result of periodic glacial cycles and geographic isolation. The regional fauna may have undergone several range con-tractions and expansions during the Pleistocene glaciations. However, the population expansion and refugia may vary in space, time, and extent. The regional fauna of the Tibetan Plateau may be combinations of ancient movement from adjacent zoogeographical regions, speciation in situ, and postglacial colonization from adjacent areas. Geomorphic and climatic changes on the plateau definitely have a remarkable influence on the regional and adjacent biogeographic patterns, and the mechanism is very complex.

  9. The Colorado Plateau coal assessment study area, 2000 (cpstdyg)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This is a coverage of the Colorado Plateau coal assessment study area. The study area outline was drawn on the county lines that most closely outline the...

  10. A plateau-valley separation method for multifunctional surfaces characterization

    DEFF Research Database (Denmark)

    Godi, Alessandro; Kühle, A.; De Chiffre, Leonardo

    2012-01-01

    Turned multifunctional surfaces are a new typology of textured surfaces presenting a flat plateau region and deterministically distributed lubricant reservoirs. Existing standards are not suitable for the characterization of such surfaces, providing at times values without physical meaning. A new...

  11. Flora investigation kicks off on Qinghai-Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Coordinated by the CAS Kunming Institute of Botany,a project to investigate the floral germplasm resources on the Qinghai-Tibet Plateau was initiated recently in Kunming,capital of southwest China's Yunnan Province.

  12. The Colorado Plateau II : Biophysical, Socioeconomic, and Cultural Research

    OpenAIRE

    Van Riper, Charles; Mattson, David J.

    2005-01-01

    Abstract from GoogleBooks: The publication of The Colorado Plateau: Cultural, Biological, and Physical Research in 2004 marked a timely summation of current research in the Four Corners states. This new volume, derived from the seventh Biennial Conference on the Colorado Plateau in 2003, complements the previous book by again focusing on the integration of science into resource management issues. The 32 chapters range in content from measuring human impacts on cultural resources, through graz...

  13. The Colorado Plateau II : Biophysical, Socioeconomic, and Cultural Research

    OpenAIRE

    Van Riper, Charles; Mattson, David J.

    2005-01-01

    Abstract from GoogleBooks: The publication of The Colorado Plateau: Cultural, Biological, and Physical Research in 2004 marked a timely summation of current research in the Four Corners states. This new volume, derived from the seventh Biennial Conference on the Colorado Plateau in 2003, complements the previous book by again focusing on the integration of science into resource management issues. The 32 chapters range in content from measuring human impacts on cultural resources, through graz...

  14. AHP 21: Pyramid Schemes on the Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Devin Gonier

    2017-09-01

    Full Text Available The unique features of pyramid shemes and certain underlying causes for their development on the Tibetan Plateau are analyzed. Research was conducted by analyzing 521 surveys, allowing estimation of pyramid scheme activity on the Plateau and an identification of related cultural and social specificities. Firsthand accounts were collected revealing details of personal involvement. Survey data and similarities in the accounts were studied to suggest how involvement in pyramid schemes might be reduced at both institutional and individual levels.

  15. Evolution of the Ordos Plateau and environmental effects

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Based on the analysis of temporary-spatial distribution, geomorphic position, contact relationship with underlying strata and grain size of red clay, we studied the formation and environmental background of red clay. During late Miocene-Pliocene, the Ordos Block finished the transformation from the basin to the plateau, which had an obvious environmental effect on the topography, indicated by the formation of highland undergoing wind erosion and lowland receiving red clay deposits. The red clay materials were sourced from dusts carried by wind energy and covered on the initial topography. Unlike Quaternary loess dust covering the overall the Loess Plateau, red clay deposited on the highland would be transported to the lowlands by wind and fluvial process. As a result, there was no continuous "Red Clay Plateau" in the Ordos region and red clay was only preserved in former lowlands. However, red clay was discontinuously distributed through the Loess Plateau and to some extent modified the initial topography. The differential uplift in interior plateau is indicated by the uplift of northern Baiyushan, central Ziwuling and southern Weibeibeishan. The Weibeibeishan Depression formed earlier and became the sedimentary center of red clay resulting in the thicker red clay deposits in Chaona, Lingtai and Xunyi. Since Quaternary the aridity in the northern plateau enhanced and accelerated loess accumulation caused the formation of the Loess Plateau. During the late Pleistocene the rapid uplift led to the enhancement of erosion. Especially after the cut-through of Sanme Lake by the Yellow River, the decline of base level caused the falling of ground water level and at the same time the increase of drainage density resulting in the enhancement of evaporation capacity, which enhanced the aridity tendency of aridity in the Loess Plateau region.

  16. Nutrient Lossed in Soils on Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    PENGLIN; WANGJI-ZENG; 等

    1995-01-01

    The soil nutrient losses due to excessive soil loss on Loess Plateau were studied by means of runoff plots and systematical determination of soil nutrients both in sediments and runoff.The results show that the amounts of nutrient losses depended on the amounts of ersoion sediments.Along with sediment,11-197kg nitrogen/hectare and 9-174kg phosphorus/hectare were lost,accounting for 92.46-99.47 percent of the total amount of nitrogen loss and 99.85-99.99 percent of the total amount of phosphorus loss respectively.The nutrient losses,very small in runoff,were mainly attributed to erosion of a few rainstorms during a year.The nutrient level in sediment was mostly higher than that in the original soil.Planting grass evidently redued the losses of soil nutrients.The N level was lower in runoff than in rainfall so that the N loss from runoff could be made up by rainfall.Fertilizer application to crops raised the nutrient level in runoff.

  17. Solution of the Kirchhoff-Plateau Problem

    Science.gov (United States)

    Giusteri, Giulio G.; Lussardi, Luca; Fried, Eliot

    2017-01-01

    The Kirchhoff-Plateau problem concerns the equilibrium shapes of a system in which a flexible filament in the form of a closed loop is spanned by a liquid film, with the filament being modeled as a Kirchhoff rod and the action of the spanning surface being solely due to surface tension. We establish the existence of an equilibrium shape that minimizes the total energy of the system under the physical constraint of noninterpenetration of matter, but allowing for points on the surface of the bounding loop to come into contact. In our treatment, the bounding loop retains a finite cross-sectional thickness and a nonvanishing volume, while the liquid film is represented by a set with finite two-dimensional Hausdorff measure. Moreover, the region where the liquid film touches the surface of the bounding loop is not prescribed a priori. Our mathematical results substantiate the physical relevance of the chosen model. Indeed, no matter how strong is the competition between surface tension and the elastic response of the filament, the system is always able to adjust to achieve a configuration that complies with the physical constraints encountered in experiments.

  18. Dendroclimatic reconstructions for the southern Colorado plateau

    Energy Technology Data Exchange (ETDEWEB)

    Dean, J.S.; Funkhouser, G.S. [Univ. of Arizona, Tucson, AZ (United States)

    1995-09-01

    A geographical network of climate sensitive tree-ring chronologies consisting of 25 archaeological sequences and two bristlecone pine series provides the basis for high resolution reconstructions of low and high frequency climatic variability on the southern Colorado Plateau over the last 1,500 years. Qualitative and quantitative dendroclimatic analyses of these data produce annual retrodictions of yearly and seasonal precipitation and summer Palmer Drought Severity Indices for each station and reconstructions of regional scale patterns in climatic variability. These reconstructions provide detailed information on climatic fluctuations that affected biotic and human populations as well as long-term baseline data for evaluating present-day climate and estimating future climatic trends. When integrated with other measures of past environmental variability, these reconstructions specify periods of favorable and unfavorable environmental conditions that would have affected past human populations of the region. The severest degradation, which occurred between A.D. 1250 and 1450, probably was causally related to numerous cultural changes that occurred at the end of the l3th century including the Anasazi abandonment of the Four Comers area. Projecting environmental patterns that characterized the last two millennia into the future indicates potential hazards to long term uranium mill waste disposal and containment and the potential and limitations of environmental restoration.

  19. Does the climate warming hiatus exist over the Tibetan Plateau?

    Science.gov (United States)

    Duan, Anmin; Xiao, Zhixiang

    2015-09-02

    The surface air temperature change over the Tibetan Plateau is determined based on historical observations from 1980 to 2013. In contrast to the cooling trend in the rest of China, and the global warming hiatus post-1990s, an accelerated warming trend has appeared over the Tibetan Plateau during 1998-2013 (0.25 °C decade(-1)), compared with that during 1980-1997 (0.21 °C decade(-1)). Further results indicate that, to some degree, such an accelerated warming trend might be attributable to cloud-radiation feedback. The increased nocturnal cloud over the northern Tibetan Plateau would warm the nighttime temperature via enhanced atmospheric back-radiation, while the decreased daytime cloud over the southern Tibetan Plateau would induce the daytime sunshine duration to increase, resulting in surface air temperature warming. Meanwhile, the in situ surface wind speed has recovered gradually since 1998, and thus the energy concentration cannot explain the accelerated warming trend over the Tibetan Plateau after the 1990s. It is suggested that cloud-radiation feedback may play an important role in modulating the recent accelerated warming trend over the Tibetan Plateau.

  20. Does the climate warming hiatus exist over the Tibetan Plateau?

    Science.gov (United States)

    Duan, Anmin; Xiao, Zhixiang

    2015-01-01

    The surface air temperature change over the Tibetan Plateau is determined based on historical observations from 1980 to 2013. In contrast to the cooling trend in the rest of China, and the global warming hiatus post-1990s, an accelerated warming trend has appeared over the Tibetan Plateau during 1998–2013 (0.25 °C decade−1), compared with that during 1980–1997 (0.21 °C decade−1). Further results indicate that, to some degree, such an accelerated warming trend might be attributable to cloud–radiation feedback. The increased nocturnal cloud over the northern Tibetan Plateau would warm the nighttime temperature via enhanced atmospheric back-radiation, while the decreased daytime cloud over the southern Tibetan Plateau would induce the daytime sunshine duration to increase, resulting in surface air temperature warming. Meanwhile, the in situ surface wind speed has recovered gradually since 1998, and thus the energy concentration cannot explain the accelerated warming trend over the Tibetan Plateau after the 1990s. It is suggested that cloud–radiation feedback may play an important role in modulating the recent accelerated warming trend over the Tibetan Plateau. PMID:26329678

  1. Understanding relationships among abundance, extirpation,and climate at ecoregional scales

    Science.gov (United States)

    Beever, Erik A.; Solomon Dubrowski,; ,; ,; J. Long,; ,; A. Mysnberge,; Piekielek, N. B.

    2014-01-01

    Recent research on mountain-dwelling species has illustrated changes in species’ distributional patterns in response to climate change. Abundance of a species will likely provide an earlier warning indicator of change than will occupancy, yet relationships between abundance and climatic factors have received less attention. We tested whether predictors of counts of American pikas (Ochotona princeps) during surveys from the Great Basin region in 1994–1999 and 2003–2008 differed between the two periods. Additionally, we tested whether various modeled aspects of ecohydrology better predicted relative density than did average annual precipitation, and whether risk of site-wide extirpation predicted subsequent population counts of pikas. We observed several patterns of change in pika abundance at range edges that likely constitute early warnings of distributional shifts. Predictors of pika abundance differed strongly between the survey periods, as did pika extirpation patterns previously reported from this region. Additionally, maximum snowpack and growing-season precipitation resulted in better-supported models than those using average annual precipitation, and constituted two of the top three predictors of pika density in the 2000s surveys (affecting pikas perhaps via vegetation). Unexpectedly, we found that extirpation risk positively predicted subsequent population size. Our results emphasize the need to clarify mechanisms underlying biotic responses to recent climate change at organism-relevant scales, to inform management and conservation strategies for species of concern.

  2. Eocene Tibetan Plateau remnants preserved in the Northwest Himalaya

    Science.gov (United States)

    van der Beek, P. A.; van Melle, J.; Guillot, S.; Pêcher, A.; Reiners, P. W.; Nicolescu, S.; Latif, M.

    2009-04-01

    The northwest Himalaya shows strongly contrasting relief, opposing deeply incised mountain ranges characterized by extremely rapid exhumation and some of the highest peaks in the world (i.e., the Karakorum range and Nanga Parbat massif) to high-elevation, low-relief areas such as the 4000-m high Deosai plateau in northern Pakistan and the 5000-m high Tso Morari in Indian Ladakh. The origin and evolution of such plateau regions in the syntaxis of the most active continental collision in the world remain elusive. Here, we report the first low-temperature thermochronology (apatite fission-track, apatite and zircon (U-Th)/He) data from the Deosai plateau and use thermal history modelling to show that it has undergone continuous slow (≤ 200 m/Myr) denudation and has thus remained tectonically stable for the last 35 Myr at least. The inferred history of constant slow denudation of the plateau contradicts the hypothesis that widespread low-relief surfaces in the northwest Himalaya result from efficient, km-scale glacial erosion during Quaternary times; such erosion would have been recorded as a phase of rapid recent denudation that is not observed in the data. Slow continuous denudation since Eocene times, i.e. only 15-20 Myr after the onset of India-Asia collision implies that the Deosai plateau surface developed early in the Himalayan history and limits the phase of orogenic relief growth in the Ladakh-Kohistan arc to the early Paleogene. Although thermochronology data do not directly record surface uplift, the simplest explanation for the inferred constant denudation rates is that the plateau had reached its present-day elevation already during the Eocene, as a later phase of surface uplift would have triggered an erosional response that would have been recorded by the thermochronology data. We use morphological analyses to characterise such plateaux and identify them at the scale of the entire northwest Himalaya and compare our thermochronological data with

  3. Aftershock Decay Rates in the Iranian Plateau

    Science.gov (United States)

    Ommi, S.; Zafarani, H.; Zare, M.

    2016-07-01

    Motivated by the desire to have more information following the occurrence of damaging events, the main purpose of this article is to study aftershock sequence parameters in the Iranian plateau. To this end, the catalogue of the Iranian earthquakes between 2002 to the end of 2013 has been collected and homogenized among which 15 earthquakes have been selected to study their aftershock decay rates. For different tectonic provinces, the completeness magnitudes ( M c) of the earthquake catalogue have been calculated in different time intervals. Also, the M c variability in spatial and temporal windows has been determined for each selected event. For major Iranian earthquakes, catalogue of aftershocks has been collected thanks to three declustering methods: first, the classical windowing method of Gardner and Knopoff (Bull Seismol Soc Am 64:1363-1367, 1974); second, a modified version of this using spatial windowing based on the Wells and Coppersmith (Bull Seismol Soc Am 84:974-1002, 1994) relations; and third, the Burkhard and Grünthal (Swiss J Geosci 102:149-188, 2009) scheme. Effects of the temporal windows also have been investigated using the time periods of 1 month, 100 days, and 1 year in the declustering method of Gardner and Knopoff (Bull Seismol Soc Am 64:1363-1367, 1974). In the next step, the modified Omori law coefficients have been calculated for the 15 selected earthquakes. The calibrated regional generic model describing the temporal and magnitude distribution of aftershocks is of interest for time-dependent seismic hazard forecasts. The regional characteristics of the aftershock decay rates have been studied for the selected Iranian earthquakes in the Alborz, Zagros and Central Iran regions considering their different seismotectonics regimes. However, due to the lack of sufficient data, no results have been reported for the Kopeh-Dagh and Makran seismotectonic regions.

  4. Amplitude of climatic changes in Qinghai-Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    On the basis of ice core and meteorological data from the Qinghai-Tibetan (Q-T) Plateau, this article focuses on the discussion of the problems related to the sensitivity of temporal and spatial changes of the climate in high-altitude regions, particularly in the Q-T Plateau. The features of abrupt climatic changes of the past 100 ka, 2 000 a and recent years indicate that the amplitude of these changes in the Q-T Plateau was obviously larger than that in low-altitude regions. The scope of temperature change above 6 000 m in the Q-T Plateau between glacial and interglacial stages could reach over 10℃, but only about 4℃ in low-elevation regions close to sea level. During the last 2 000 a, the amplitude of temperature changes at Guliya (over 6 000 m a.s.l.) in the Q-T Plateau reached 7℃, in comparison with 2℃ in eastern China at low altitude. In the present age, apparent differences of climatic warming have been observed in the Q-T Plateau, indicating that the warming in high-elevation regions is much higher than that in low-elevation regions. The temperature in over 3 500 m regions of the Q-T Plateau have been increasing at a rate of 0.25×10-1/a in recent 30 years, but almost no change has taken place in the regions below 500 m. Thus, we concluded that high-altitude regions are more sensitive to climatic changes than the low-altitude regions.

  5. The Colorado Plateau II: biophysical, socioeconomic, and cultural research

    Science.gov (United States)

    Mattson, David J.; van Riper, Charles

    2005-01-01

    The publication of The Colorado Plateau: Cultural, Biological, and Physical Research in 2004 marked a timely summation of current research in the Four Corners states. This new volume, derived from the seventh Biennial Conference on the Colorado Plateau in 2003, complements the previous book by focusing on the integration of science into resource management issues. The 32 chapters range in content from measuring human impacts on cultural resources, through grazing and the wildland-urban interface issues, to parameters of climate change on the Plateau. The book also introduces economic perspectives by considering shifting patterns and regional disparities in the Colorado Plateau economy. A series of chapters on mountain lions explores the human-wildland interface. These chapters deal with the entire spectrum of challenges associated with managing this large mammal species in Arizona and on the Colorado Plateau, conveying a wealth of timely information of interest to wildlife managers and enthusiasts. Another provocative set of chapters on biophysical resources explores the management of forest restoration, from the micro scale all the way up to large-scale GIS analyses of ponderosa pine ecosystems on the Colorado Plateau. Given recent concerns for forest health in the wake of fires, severe drought, and bark-beetle infestation, these chapters will prove enlightening for forest service, park service, and land management professionals at both the federal and state level, as well as general readers interested in how forest management practices will ultimately affect their recreation activities. With broad coverage that touches on topics as diverse as movement patterns of rattlesnakes, calculating watersheds, and rescuing looted rockshelters, this volume stands as a compendium of cutting-edge research on the Colorado Plateau that offers a wealth of insights for many scholars.

  6. Gravitational salt tectonics above a rising basement plateau offshore Algeria

    Science.gov (United States)

    Gaullier, Virginie; Vendeville, Bruno C.; Besème, Grégoire; Legoux, Gaetan; Déverchère, Jacques; Lymer, Gaël

    2017-04-01

    Seismic data (survey "MARADJA 1", 2003) offshore the Algerian coast have imaged an unexpected deformation pattern of the Messinian salt (Mobile Unit; MU) and its sedimentary overburden (Messinian Upper Unit and Plio-Quaternary) above an actively rising plateau in the subsalt basement. From a geodynamic point of view, the region is undergoing crustal convergence, as attested by the Boumerdes earthquake (2003, magnitude 6.8). The rise of this plateau, forming a 3D promontory restricted to the area offshore Algiers, is associated with that geodynamic setting. The seismic profiles show several subsalt thrusts (Domzig et al. 2006). The data provided additional information on the deformation of the Messinian mobile evaporitic unit and its Plio-Quaternary overburden. Margin-perpendicular profiles show mostly compressional features (anticlines and synclines) that had little activity during Messinian times, then grew more during Plio-Quaternary times. A few normal faults are also present, but are not accompanied by salt rise. By contrast, margin-parallel profiles clearly show that extensional, reactive salt diapiric ridges (symptomatic with their triangular shape in cross section) formed early, as early as the time of deposition of the Messinian Upper Unit, as recorded by fan-shaped strata. These ridges have recorded E-W, thin-skinned gravity gliding above the Messinian salt, as a response to the rise of the basement plateau. We tested this hypothesis using two analogue models, one where we assumed that the rise of the plateau started after Messinian times (initially tabular salt across the entire region), the second model assumed that the plateau had already risen partially as the Messininan Mobile Unit was deposited (salt initially thinner above the plateau than in the adjacent regions). In both experiments, the rise of the plateau generated preferential E-W extension above the salt, combined with N-S shortening. Extension was caused by gravity gliding of the salt from

  7. Red Clay Sediment in the Central Chinese Loess Plateau and Its Implication for the Uplift of the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    SONG Yougui; LI Jijun; FANG Xiaomin; XIA Fei; DONG Hongmei

    2005-01-01

    The widely distributed red clay sediment underlying the Chinese Loess Plateau truly records the Neogene environmental evolution, and its genesis and development are intrinsically related to the uplift processes of the Tibetan Plateau and the evolution of East Asia monsoon system. In this paper, a detailed magnetostratigraphy of a loess-red clay section (107°13′E, 35°02′N) from the central Loess Plateau is reported. The loess-red clay sequence is composed of 175 m Quaternary loess-paleosol sequence and 128 m Neogene red clay sediments. Based on the correlation with the standard geomagnetic polarity time scale, the paleomagnetic results indicate that the age of Chaona red clay sequence extends to 8.1Ma, which is the older red clay deposition in the central Chinese Loess Plateau. The commencement of red clay at ~8.1 Ma may imply that the Ordos planation surface was broken by the movement of the Haiyuan-Liupanshan Faults, which was related to the uplift of the Tibetan Plateau induced by the collision of India Plate and Eurasian Plate. And the western part adjacent to the Tibetan Plateau was uplifted to form the embryo of the Liupan Shan (Mts.) and the eastern part was down-faulted to receive red clay deposition. We link this faulting to an initial uplift of the Tibetan Plateau. The undulating nature of the broken Ordos planation surface may explain the chronological differences and depth discrepancies among various cross-sections of red clay.

  8. Seismic wave speed structure of the Ontong Java Plateau

    Science.gov (United States)

    Covellone, Brian M.; Savage, Brian; Shen, Yang

    2015-06-01

    The Ontong Java Plateau (OJP) represents the result of a significant event in the Earth's geologic history. Limited geophysical and geochemical data, as well as the plateau's relative isolation in the Pacific ocean, have made interpretation of the modern day geologic structure and its 120 Ma formation history difficult. Here we present the highest resolution image to date of the wave speed structure of the OJP region. We use a data set that combines Rayleigh waves extracted from both ambient noise and earthquake waveforms and an iterative finite-frequency tomography methodology. The combination of datasets allow us to best exploit the limited station distribution in the Pacific and image wave speed structures between 35 km and 300 km into the Earth. We image a region of fast shear wave speeds, greater than 4.75 km/s, that extends to greater than 100 km beneath the plateau. The wave speeds are similar to as observed in cratonic environments and are consistent with a compositional anomaly that resulted from the residuum of eclogite entrainment during the plateau's formation. The combination of our imaged wave speed structure and previous geochemical work suggest that a surfacing plume head entrained eclogite from the deep mantle and accounts for the anomalous buoyancy characteristics of the plateau and observed fast wave speeds.

  9. Spontaneous collapse of the tibial plateau: radiological staging

    Energy Technology Data Exchange (ETDEWEB)

    Carpintero, P.; Leon, F.; Zafra, M. [University Hospital ' ' Reina Sofia' ' , Orthopaedic Department, Cordoba (Spain); Montero, R.; Carreto, A. [University Hospital ' ' Reina Sofia' ' , Radiology Department, Cordoba (Spain)

    2005-07-01

    This paper proposes a radiological staging system for necrosis of the tibial plateau, similar to those already developed for the hip and the medial femoral condyle. We retrospectively studied the clinical case histories and radiographic findings of 14 patients (15 affected knees) with histologically proven osteonecrosis of the tibial plateau. Stage I was marked by normal radiograph, but increased uptake in bone scan and subchondral areas of abnormal marrow signal intensity in magnetic resonance imaging (MRI), as reported in other osteonecrosis sites. Stage II was characterised by cystic and sclerotic changes, and stage III fracture of the medial rim of the medial tibial plateau and tibial plateau collapse were present. Stage IV was marked by joint narrowing. These changes appeared earlier and were more pronounced when there was genu varum/valgum or involvement of the lateral tibial plateau. The radiological evolution of the disease appears to follow a four-stage course over a period of roughly one year from the onset of symptoms. (orig.)

  10. Verçenik Plateau Alternative Tourism and Recreational Activities

    Directory of Open Access Journals (Sweden)

    İzzet İSLAMOĞLU

    2014-08-01

    Full Text Available In the last century working life become easier and result of this increased people free time, after that interest of tourism activities wide spread all over. Plateau tourism or highland places are not first choices of the tourism activities but plateau rec reation will give an application for potential activity place. Turkey have unmatched nature and rich environmental resources will able to give any kind of tourism activities. In that context city of Rize took place in Black Sea region with different capabi lities, one of the source areas that make up tourism and recreational activities. This research intended for Vercenik Plateau take place 60 km away from Camlihemsin district center and will determine potential tourism and recreational application. Research is based on field observation and studies. This information obtained as a result ofthis evaluationbeing associated toliterature data and that information determined which exercise can be done in the field. Vercenik Plateau; with pristine environment and ru ral locations, the fresh water supplies, unique flora for city of Rize has high recreational capacities.As a result of study; Vercenik Plateau has natural features with the great potential of the alternative tourism as it is suitable for areas but not asse ss enough potential tourism and recreational activities without prior review has been observed.

  11. Rapid Loss of Lakes on the Mongolian Plateau

    Science.gov (United States)

    Tao, S.; Fang, J.; Zhao, X.; Zhao, S.; Shen, H.; Hu, H.; Tang, Z.; Wang, Z.; Guo, Q.

    2015-12-01

    Lakes are widely distributed on the Mongolian Plateau and as critical water sources have sustained Mongolian pastures for hundreds of years. However, the plateau has experienced significant lake shrinkage and grassland degradation during the past several decades. To quantify the changes in all the lakes on the plateau and the associated driving factors, we performed a satellite-based survey using multi-temporal Landsat images from the 1970s to 2000s, combining with ground-based censuses. Our results document a rapid loss of lakes on the plateau in the past decades: the number of lakes with a water surface area >1 km2 decreased from 785 in the late 1980s to 577 in 2010, with a greater rate of decrease (34.0%) in Inner Mongolia of China than in Mongolia (17.6%). This decrease has been particularly pronounced since the late 1990s in Inner Mongolia and the number of lakes >10 km2 has declined by 30.0%. The statistical analyses suggested that in Mongolia precipitation was the dominant driver for the lake changes, while in Inner Mongolia coal mining was most important in its grassland area and irrigation was the leading factor in its cultivated area. The deterioration of lakes is expected to continue in the following decades not only because of changing climate but also increasing exploitation of underground mineral and groundwater resources on the plateau. To protect grasslands and the indigenous nomads, effective action is urgently required to save these valuable lakes from further deterioration.

  12. Fraturas do planalto tibial Tibial plateau fractures

    Directory of Open Access Journals (Sweden)

    Maurício Kfuri Júnior

    2009-01-01

    Full Text Available As fraturas do planalto tibial são lesões articulares cujos princípios de tratamento envolvem a redução anatômica da superfície articular e a restauração funcional do eixo mecânico do membro inferior. Contribuem para a tomada de decisões no tratamento dessas fraturas o perfil do paciente, as condições do envelope de tecidos moles, a existência de outros traumatismos associados e a infraestrutura disponível para abordagens cirúrgicas. Para as fraturas de alta energia, o tratamento estagiado, seguindo o princípio do controle de danos, tem como prioridade a manutenção do alinhamento do membro enquanto se aguarda a resolução das más condições de tecidos moles. Já nos traumas de baixa energia, desde que os tecidos moles não sejam um fator adverso, o tratamento deve ser realizado em tempo único, com osteossíntese definitiva. Fixação estável e movimento precoce são variáveis diretamente relacionadas com os melhores prognósticos. Desenvolvimentos recentes, como os implantes com estabilidade angular, substitutos ósseos e imagens tridimensionais para controle intraoperatório, deverão contribuir para cirurgias menos invasivas e melhores resultados.Tibial plateau fractures are joint lesions that require anatomical reduction of joint surface and functional restoration of mechanical axis of a lower limb. Patient profile, soft tissue conditions, presence of associated injuries and the available infrastructure for the treatment all contribute to the decision making about the best treatment for these fractures. High-energy fractures are usually approached in a staged manner respecting the principle of damage control, and are primarily targeted to maintain limb alignment while the resolution unfavorable soft tissue conditions is pending. Low-energy trauma can be managed on a single-stage basis, provided soft tissues are not an adverse factor, with open reduction and internal f-ixation. Stable fixation and early painless joint

  13. Characteristics of land-atmosphere energy and turbulentfluxes over the plateau steppe in central Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    The land-atmosphere energy and turbulence exchange is key to understanding land surface processes on the TibetanPlateau (TP). Using observed data for Aug. 4 to Dec. 3, 2012 from the Bujiao observation point (BJ) of the Nagqu PlateauClimate and Environment Station (NPCE-BJ), different characteristics of the energy flux during the Asian summermonsoon (ASM) season and post-monsoon period were analyzed. This study outlines the impact of the ASM on energyfluxes in the central TP. It also demonstrates that the surface energy closure rate during the ASM season is higher than thatof the post-monsoon period. Footprint modeling shows the distribution of data quality assessments (QA) and qualitycontrols (QC) surrounding the observation point. The measured turbulent flux data at the NPCE-BJ site were highly representativeof the target land-use type. The target surface contributed more to the fluxes under unstable conditions thanunder stable conditions. The main wind directions (180° and 210°) with the highest data density showed flux contributionsreaching 100%, even under stable conditions. The lowest flux contributions were found in sectors with low data density,e.g., 90.4% in the 360° sector under stable conditions during the ASM season. Lastly, a surface energy water balance(SEWAB) model was used to gap-fill any absent or corrected turbulence data. The potential simulation error was alsoexplored in this study. The Nash-Sutcliffe model efficiency coefficients (NSEs) of the observed fluxes with the SEWABmodel runs were 0.78 for sensible heat flux and 0.63 for latent heat flux during the ASM season, but unrealistic values of?0.9 for latent heat flux during the post-monsoon period.

  14. 森林鼠兔害发生特点及防控措施%Study on the occurrence characteristics of forest pika disaster and its control measures of Mulan Forestry Administration

    Institute of Scientific and Technical Information of China (English)

    马莉

    2015-01-01

    Since the 70’s of the last century , the Mulan Forestry Administration has wit‐nessed the pika hazard occurrence in artificial larch and Pinus tabulae f ormis forest in new plantation from sporadically into widespreadedly ,which endangers both the development of newly planted saplings of L arix gmelinii ,Pinus tabuli f ormis ,Pinus sylvestris ,Picea aspe‐rata plantation and greening seedlings ,affecting the afforestation effect ,reducing the eco‐nomic benefits of greening seedlings .In the practice ,effective prevention and treatments are conducted with the original apple cuts mixed with zinc phosphide ,wheat mixed with broma‐diolone ,seedling trunks smeared with repellent ,baits by dosing protector ,indicating that there is a continuous progress in its prevention and control technology ,and therefore the afforestation achievements have been effectively protected ,and an advanced ,well feasible , and economical prevention and control technology has been established .%自20世纪70年代开始,木兰林区森林鼠兔害由零星发生转化为普遍发生,由危害新造林地幼树发展到危害落叶松、油松、樟子松、云杉幼林地及绿化大苗,影响造林绿化成效,降低绿化大苗经济效益。为防控鼠兔危害,主要采取了苹果切块拌磷化锌、小麦拌溴敌隆、苗干涂抹驱避剂、保护器投药饵等方法,有效地保护了造林成果,在实践中逐渐探索出一条技术先进、生产可行、经济上合算的防治技术措施。

  15. ANALYSIS OF MESOSCALE CONVECTIVE SYSTEMS OVER TIBETAN PLATEAU IN SUMMER

    Institute of Scientific and Technical Information of China (English)

    GUO Zhong-yang; DAI Xiao-yan; WU Jian-ping; LIN Hui

    2006-01-01

    In this paper, Geostationary Meteorological Satellite (GMS) infrared black-body temperature (Tbb) data from June to August 1998 are used to automatically track the activity of Mesoscale Convective System (MCS) over the Tibetan Plateau in China. Consequently, the features of MCS, such as area, intensity, life cycle, activity region and shape, are obtained. High Resolution Limited Area Analysis and Forecasting System (HLAFS) values provided by China National Meteorological Center are used to study the relationships between the MCS trajectories and their environmental physical field values, based on the distribution and trajectories of MCSs over the Tibetan Plateau. Favorable environmental physical field charts of influencing MCS movement out of the Tibetan Plateau in different UTC (Universal Time Coordinate) are developed by using spatial data mining techniques at levels of 400hPa and 500hPa, respectively.

  16. More evidence of the plateau effect: a social perspective.

    Science.gov (United States)

    Pinto-Prades, J L; Lopez-Nicolás, A

    1998-01-01

    The purpose of this study was to test the existence of the plateau effect at the social level. The authors tried to confirm the preliminary conclusion that people may not be willing to trade off any longevity to improve the health state of a large number of people if the health states are mild enough. They tested this assumption using the person-tradeoff technique. They also used a parametric approach and a nonparametric approach to study the relationship between individual and social values. Results show the existence of the plateau effect in the context of resource allocation. Furthermore, with the nonparametric approach, a plateau effect in the middle part of the scale was also observed, suggesting that social preference may not be directly predicted from individual utilities. The authors caution against the possible framing effects that may be present in these kinds of questions.

  17. State of tectonic stress in Shillong Plateau of northeast India

    Science.gov (United States)

    Baruah, Santanu; Baruah, Saurabh; Saikia, Sowrav; Shrivastava, Mahesh N.; Sharma, Antara; Reddy, C. D.; Kayal, J. R.

    2016-10-01

    Tectonic stress regime in the Shillong plateau, northeast region of India, is examined by stress tensor inversion. Some 97 reliable fault plane solutions are used for stress inversion by the Michael and Gauss methods. Although an overall NNW-SSE compressional stress is observed in the area, the stress regime varies from western part to eastern part of the plateau. The eastern part of the plateau is dominated by NNE-SSW compression and the western part by NNW-SSE compression. The NNW-SSE compression in the western part may be due to the tectonic loading induced by the Himalayan orogeny in the north, and the NNE-SSW compression in the eastern part may be attributed to the influence of oblique convergence of the Indian plate beneath the Indo-Burma ranges. Further, Gravitational Potential Energy (GPE) derived stress also indicates a variation from west to east.

  18. Fukushima nuclear accident recorded in Tibetan Plateau snow pits.

    Directory of Open Access Journals (Sweden)

    Ninglian Wang

    Full Text Available The β radioactivity of snow-pit samples collected in the spring of 2011 on four Tibetan Plateau glaciers demonstrate a remarkable peak in each snow pit profile, with peaks about ten to tens of times higher than background levels. The timing of these peaks suggests that the high radioactivity resulted from the Fukushima nuclear accident that occurred on March 11, 2011 in eastern Japan. Fallout monitoring studies demonstrate that this radioactive material was transported by the westerlies across the middle latitudes of the Northern Hemisphere. The depth of the peak β radioactivity in each snow pit compared with observational precipitation records, suggests that the radioactive fallout reached the Tibetan Plateau and was deposited on glacier surfaces in late March 2011, or approximately 20 days after the nuclear accident. The radioactive fallout existed in the atmosphere over the Tibetan Plateau for about one month.

  19. An avifaunal case study of a plateau from Goa, India: an eye opener for conservation of plateau ecosystems

    Directory of Open Access Journals (Sweden)

    Minal Desai

    2012-03-01

    Full Text Available The lateritic plateaux typical of the midlands between the Western Ghats and the coastal plains of the Arabian Sea are known to be a unique ecosystem with a sizeable endemic flora. However, there is a total lack of studies on the faunal diversity of these plateaux, which are currently experiencing enormous anthropogenic pressures. We conducted a year-long study on the avifauna of the Taleigao Plateau, Goa. The Taleigao Plateau harbours 114 species of birds, accounting for 37% of the avifaunal diversity of the state. The resident bird population did not vary significantly through the seasons. Among the migrant birds, Rosy Starling Sturnus roseus was particularly partial to the plateau. Besides, five species of larks, grassland specialists were also recorded on the plateau. However, the absence of forest birds like the Malabar Pied Hornbill and the Indian Grey Hornbill (recorded earlier and the predominance of habitat generalists like the House Crow and the Jungle Myna seemed to be the offshoot of heavy anthropogenic pressures on the plateau. It is recommended that at least some plateaux in the belt deserve to be protected from the impact of unsustainable developmental process

  20. The impacts of the summer plateau monsoon over the Tibetan Plateau on the rainfall in the Tarim Basin, China

    Science.gov (United States)

    Zhao, Yong; Huang, Anning; Zhou, Yang; Yang, Qing

    2016-10-01

    The impacts of the summer plateau monsoon (PM) over the Tibetan Plateau on summer rainfall over the Tarim Basin in northwest China are investigated, based on the observed rainfall data at 34 stations and the NCEP/NCAR reanalysis data during 1961 to 2007. Results showed that the PM is well correlated to the summer rainfall over the Tarim Basin. Process analysis shows that strong PM corresponds to an anomalous cyclone over the Tibetan Plateau in the middle troposphere and an anomalous anticyclone in the upper troposphere over northwest part of Tibetan Plateau. They result in cold air moving from high latitudes into Central Asia over the western part of Tibetan Plateau. The concurrences of the cooling in the middle-upper troposphere over Central Asia leads to an anomalous cyclone over Central Asia at 500 hPa and the anomalous descending motions prevailing over the cooling region. Associated with this anomaly, there are enhanced southerly winds and corresponding ascending motion over the Tarim Basin located in the east of the cooling region. These processes lead to more summer rainfall over the Tarim Basin.

  1. In vitro comparison of tibial plateau leveling osteotomy with and without use of a tibial plateau leveling jig.

    Science.gov (United States)

    Schmerbach, Kay Ingo; Boeltzig, Christian Konrad Matthias; Reif, Ullrich; Wieser, Jan Carsten; Keller, Thomas; Grevel, Vera

    2007-02-01

    To evaluate the influence of a tibial plateau leveling jig on osteotomy orientation, fragment reduction, and postoperative tibial plateau angle (TPA) during tibial plateau leveling osteotomy (TPLO). In vitro experimental study. Large-breed canine cadavers (n=20). TPLO was performed on 40 hindlimbs using 4 methods. Group 1: Jig; dogs in dorsal recumbency with the osteotomy parallel to the distal jig pin. Groups 2-4: No jig; dogs in lateral recumbency with the osteotomy in a vertical orientation (group 2: tibia parallel to the table top; group 3: controlled superimposition of the femoral condyles; group 4: internal rotation of the tibia). Postoperative TPA, fragment reduction, and osteotomy orientation relative to the tibial plateau were compared. Positive or negative values denoted deviation from parallel relative to the tibial plateau. Postoperative TPA, fragment reduction, and proximodistal osteotomy orientation were not significantly different between groups. Craniocaudal osteotomy orientation was significantly different (Ptable surface. TPLO without use of a jig reduces surgical trauma, is less time consuming, and reduces cost.

  2. An avifaunal case study of a plateau from Goa, India: an eye opener for conservation of plateau ecosystems

    Directory of Open Access Journals (Sweden)

    Minal Desai

    2012-03-01

    Full Text Available The lateritic plateaux typical of the midlands between the Western Ghats and the coastal plains of the Arabian Sea are known to be a unique ecosystem with a sizeable endemic flora. However, there is a total lack of studies on the faunal diversity of these plateaux, which are currently experiencing enormous anthropogenic pressures. We conducted a year-long study on the avifauna of the Taleigao Plateau, Goa. The Taleigao Plateau harbours 114 species of birds, accounting for 37% of the avifaunal diversity of the state. The resident bird population did not vary significantly through the seasons. Among the migrant birds, Rosy Starling Sturnus roseus was particularly partial to the plateau. Besides, five species of larks, grassland specialists were also recorded on the plateau. However, the absence of forest birds like the Malabar Pied Hornbill and the Indian Grey Hornbill (recorded earlier and the predominance of habitat generalists like the House Crow and the Jungle Myna seemed to be the offshoot of heavy anthropogenic pressures on the plateau. It is recommended that at least some plateaux in the belt deserve to be protected from the impact of unsustainable developmental process

  3. 40 CFR 81.162 - Northeast Plateau Intrastate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Air Quality Control Regions § 81.162 Northeast Plateau Intrastate Air Quality Control Region. The Northeast Plateau Intrastate Air Quality Control Region (California) consists of the territorial area... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Northeast Plateau Intrastate...

  4. Discovery of cryptic Armillaria solidipes genotypes within the Colorado Plateau

    Science.gov (United States)

    J. W. Hanna; N. B. Klopfenstein; M. -S. Kim; S. M. Ashiglar; A. L. Ross-Davis; G. I. McDonald

    2012-01-01

    Armillaria solidipes (= A. ostoyae) is a root-disease pathogen that causes severe losses in growth and productivity of forest trees throughout the Northern Hemisphere. This species is genetically diverse with variable disease activities across different regions of the world. In North America, A. solidipes in the Colorado Plateau exists in drier habitats and causes more...

  5. Spatial Distribution of Soil Erosion Sensitivity on the Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-Dan; ZHONG Xiang-Hao; FAN Jian-Rong

    2005-01-01

    The Tibet Plateau, occupying the main part of Qinghai-Tibet Plateau and having an average altitude of 4 500 m, has geomorphological features that are unique in the world, with soil erosion being one of the main ecological problems. Thus the main objectives of the present research were to set up an efficient and simple way of evaluating spatial distribution of soil erosion sensitivity in the Tibet Plateau as well as the responses of soil erosion to changes of natural environmental conditions, and to indicate key regions where soil erosion should be preferentially controlled. Based on the Universal Soil Loss Equation (USLE), the study applied geographic information system (GIS) technology to develop a methodological reference framework, from which soil erosion sensitivity could be evaluated. The impact of precipitation, soil, topography and vegetation on soil erosion was divided into classes of extreme sensitivity, high sensitivity, medium sensitivity, low sensitivity and no sensitivity. With the aid of GIS, the resultant map from overlaying various factors showed that soil erosion sensitivity had great discrepancy in different parts of the region. In the southeastern part of the Tibet Plateau there were mainly three classes of sensitivity, namely, extreme, high and medium sensitivity. However, the other two classes, low and no sensitivity, were dominant in the northwestern part.

  6. Deep mantle forces and the uplift of the Colorado Plateau

    Energy Technology Data Exchange (ETDEWEB)

    Moucha, R; Forte, A M; Rowley, D B; Mitrovica, J X; Simmons, N A; Grand, S P

    2009-06-23

    Since the advent of plate tectonics, it has been speculated that the northern extension of the East Pacific Rise, specifically its mantle source, has been over-ridden by the North American Plate in the last 30 Myrs. Consequently, it has also been postulated that the opening of the Gulf of California, the extension in the Basin and Range province, and the uplift of the Colorado Plateau are the resulting continental expressions of the over-ridden mantle source of the East Pacific Rise. However, only qualitative models based solely on surface observations and heuristic, simplified conceptions of mantle convection have been used in support or against this hypothesis. We introduce a quantitative model of mantle convection that reconstructs the detailed motion of a warm mantle upwelling over the last 30 Myrs and its relative advance towards the interior of the southwestern USA. The onset and evolution of the crustal uplift in the central Basin and Range province and the Colorado Plateau is determined by tracking the topographic swell due to this mantle upwelling through time. We show that (1) the extension and magmatism in the central Basin and Range province between 25 and 10 Ma coincides with the reconstructed past position of this focused upwelling, and (2) the southwestern portion of the Colorado Plateau experienced significant uplift between 10 Ma and 5 Ma that progressed towards the northeastern portion of the plateau. These uplift estimates are consistent with a young, ca. 6 Ma, Grand Canyon model and the recent commencement of mafic magmatism.

  7. SUMMER DIURNAL CYCLE AT DOME C ON THE ANTARTIC PLATEAU

    OpenAIRE

    Barral, H.; E. Vignon; Bazile, E.; Traullé, O; Gallée, H.; Genthon, C.; Brun, C.; F. Couvreux; P. Le Moigne

    2014-01-01

    International audience; The ice-sheet offers us ”laboratory cases” with endless snow covered, relatively homogeneous, flat or sloped areas with persistent and strong stable stratifications resulting in low level jets. Dome C (75°06 S,123°E) on the East Antarctic Plateau is one of them.

  8. New transhumance in the Mahafaly Plateau region in Madagascar

    African Journals Online (AJOL)

    models influence people's capacity to adapt, especially in socio- .... pastoral mobility have mainly been described as climate change adaptation strategies ..... transhumance on the plateau, where most herders can build on a ..... and ecosystem services in southern Madagascar. .... Migration as a contribution to resilience.

  9. Ningwu——An Ancient Pass On The Plateau

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    <正>Ningwu situated on the Loess Plateau in north of Shanxi Province is one of the three passes along the Great Wall. The other two are the Pian Pass in the west and the Yanmen Pass in the east. In the ancient times, it had been a key military town in the northern Chinese borders.

  10. Heat Flow for the Minimal Surface with Plateau Boundary Condition

    Institute of Scientific and Technical Information of China (English)

    Kung Ching CHANG; Jia Quan LIU

    2003-01-01

    The heat flow for the minimal surface under Plateau boundary condition is defined to be aparabolic variational inequality, and then the existence, uniqueness, regularity, continuous dependenceon the initial data and the asymptotics are studied. It is applied as a deformation of the level sets inthe critical point theory.

  11. Oil/Gas Exploration Prospects for Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    Zhao Zhengzhang; Li Yongtie; Ye Hefei

    1997-01-01

    @@ As an important part of the Tethys, Tibet Plateau is prominent in the global geology tectonics. However, due to the limitation of local geographic conditions, the degree of geological study in this region is low, especially in the field of marine Mesozoic petroleum geological study.

  12. The Colorado Plateau IV: shaping conservation through science and management

    Science.gov (United States)

    Wakeling, Brian F.; Sisk, Thomas D.; van Riper, Charles

    2010-01-01

    Roughly centered on the Four Corners region of the southwestern United States, the Colorado Plateau covers some 130,000 square miles of sparsely vegetated plateaus, mesas, canyons, arches, and cliffs in Arizona, Utah, Colorado, and New Mexico. With elevations ranging from 3,000 to 14,000 feet, the natural systems found within the plateau are dramatically varied, from desert to alpine conditions. This book focuses on the integration of science and resource management issues in this unique and highly varied environment. Broken into three subsections, this volume addresses conservation biology, biophysical resources, and inventory and monitoring concerns. The chapters range in content, addressing conservation issues–past, present, and future–on the Colorado Plateau, measurement of human impacts on resources, grazing and wildland-urban interfaces, and tools and methods for monitoring habitats and species. An informative read for people interested in the conservation and natural history of the region, the book will also serve as a valuable reference for those people engaged in the management of cultural and biological resources of the Colorado Plateau, as well as scientists interested in methods and tools for land and resource management throughout the West.

  13. Excessive afforestation and soil drying on China's Loess Plateau

    Science.gov (United States)

    Zhang, Shulei; Yang, Dawen

    2017-04-01

    Afforestation and deforestation are human disturbances to vegetation, which have profound impacts on regional eco-hydrological processes, the water and carbon cycles, and consequently, ecosystem sustainability. Since 1999, large scale revegetation has been carried out across China's Loess Plateau following the "Grain-to-Green Program" implemented by the Chinese government. This revegetation, particularly with forest, has caused negative eco-hydrological consequences, including streamflow decline and soil drying. Here, we have used "ecosystem optimality theory" and satellite observations, to assess the water balance under the climate-defined optimal and actual vegetation cover during 1982-2010 and its responses to future climate change (2011-2050) over the Loess Plateau. Results show that the current vegetation cover (0.48 on average) has already exceeded the climate-defined optimal cover (0.43 on average) in the most recent decade, especially in the middle-to-east Loess Plateau, indicating that it is the widespread over-planting, which is primarily responsible for soil drying in the area. In addition, both the optimal vegetation cover and soil moisture tend to decrease under future climate scenarios. Our findings suggest that further revegetation on the Loess Plateau should be applied with caution. To maintain a sustainable eco-hydrological environment in the region, a revegetation threshold should be urgently set, to limit future planting.

  14. Mapping risk of plague in Qinghai-Tibetan Plateau, China.

    Science.gov (United States)

    Qian, Quan; Zhao, Jian; Fang, Liqun; Zhou, Hang; Zhang, Wenyi; Wei, Lan; Yang, Hong; Yin, Wenwu; Cao, Wuchun; Li, Qun

    2014-07-10

    Qinghai-Tibetan Plateau of China is known to be the plague endemic region where marmot (Marmota himalayana) is the primary host. Human plague cases are relatively low incidence but high mortality, which presents unique surveillance and public health challenges, because early detection through surveillance may not always be feasible and infrequent clinical cases may be misdiagnosed. Based on plague surveillance data and environmental variables, Maxent was applied to model the presence probability of plague host. 75% occurrence points were randomly selected for training model, and the rest 25% points were used for model test and validation. Maxent model performance was measured as test gain and test AUC. The optimal probability cut-off value was chosen by maximizing training sensitivity and specificity simultaneously. We used field surveillance data in an ecological niche modeling (ENM) framework to depict spatial distribution of natural foci of plague in Qinghai-Tibetan Plateau. Most human-inhabited areas at risk of exposure to enzootic plague are distributed in the east and south of the Plateau. Elevation, temperature of land surface and normalized difference vegetation index play a large part in determining the distribution of the enzootic plague. This study provided a more detailed view of spatial pattern of enzootic plague and human-inhabited areas at risk of plague. The maps could help public health authorities decide where to perform plague surveillance and take preventive measures in Qinghai-Tibetan Plateau.

  15. Thermal Stratification in Lake Zige Tangco, Central Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    LI Wan-chun; YANG Xiang-dong; YIN Yu; JI Jiang; LI Shi-jie; PU Pei-min

    2005-01-01

    Lake Zige Tangco is an endorheic saline lake in central Tibetan Plateau. Investigations of 1998 and 1999 revealed that is was a typical stratified lake. The characteristics of thermal stratification of the lake have been extensively discussed from 4 aspects, i.e. thermocline, hydrochemistry and dissolved oxygen, stable isotope oxygen, and stability. The thermocline coupled with chemocline was further analyzed.

  16. Structural model of the Balkassar area, Potwar Plateau, Pakistan

    Science.gov (United States)

    Iqbal, Shahid; Akhter, Gulraiz; Bibi, Sehrish

    2015-11-01

    Balkassar is an important hydrocarbon producing area of the Potwar Plateau, Pakistan. Two-dimensional seismic reflection data of the area revealed tectonically controlled, distinct episodes of (1) normal faulting in the basement followed by (2) reverse faulting in the cover sequence. Himalayan orogeny and associated diapirism of the Precambrian Salt Range Formation have produced many salt-cored anticlines in the Potwar Plateau, and one such salt-cored anticline is present in the Balkassar. This anticline has NE-SW-oriented axis, and both the SE and NW limbs are bounded by reverse faults. The basement normal faults indicate Jurassic rifting and splitting of Pangaea. We interpret reverse faults with dip angles of about 60°-75° in the cover sequence, having both hinterland and foreland vergence. Both NW- and SE-dipping faults are present in contrast to the only southward-directed thrusts of previous models. Duplexes and triangle zones, which are common in the northern part of the Potwar Plateau, are not developed in the Balkassar area due to comparatively less crustal shortening in the area. The present interpretation can help in understanding the complex structures in other parts of the Potwar Plateau for hydrocarbons exploration and also in deformed foreland basins worldwide that display similar characteristics but are considered to be dominated by low-angle thrust tectonics.

  17. TIBIAL PLATEAU FRACTURES – SURGICAL MANAGEMENT BY MIPPO

    Directory of Open Access Journals (Sweden)

    Bharath Raju

    2014-06-01

    Full Text Available BACKGROUND AND OBJECTIVES: Tibial plateau fractures are one of the most common intra-articular fractures. They are the outcome of indirect coronal or direct compressive forces. The incidence of tibial plateau fractures is 1.3% of all fractures. These fractures have varied degree of fracture configuration involving medial, lateral or both tibial plateaus with varied degree of intra-articular depressions and displacements. Due to speedy vehicles and mechanization there has been increase in the number of tibial plateau fractures. Knee joints being one of the major weight bearing joints of human body, these fractures are of big importance. METHODS: We studied 30 cases of tibial plateau fractures treated by MIPPO at kempegowda institute of medical sciences from June 2012 to April 2014 with minimum follow up of up to 6months. RESULTS: All the selected patients were evaluated both clinically as well as radiologically. The lab investigations were done and then they were taken up for the surgery. The fractures were classified as per schatzker’s classification and treated accordingly. In the post-op period early range of movements were started and the patients were non weight bearing till 6 weeks. Till 12 weeks partial weight bearing was allowed and full weight bearing was allowed after radiological union of the fracture. CONCLUSION: Tibial plateau fractures when treated with MIPPO give articular anatomical reduction, rigid fixation and early mobolisation of the knee joint. This prevents development of osteoarthritis and includes all the advantages of minimally invasive procedure and so better patient compliance.

  18. Into Tibet: An Early Pliocene Dispersal of Fossil Zokor (Rodentia: Spalacidae) from Mongolian Plateau to the Hinterland of Tibetan Plateau.

    Science.gov (United States)

    Li, Qiang; Wang, Xiaoming

    2015-01-01

    This paper reports the fossil zokors (Myospalacinae) collected from the lower Pliocene (~4.4 Ma) of Zanda Basin, southwestern Tibet, which is the first record in the hinterland of Tibetan Plateau within the Himalayan Range. Materials include 29 isolated molars belonging to Prosiphneus eriksoni (Schlosser, 1924) by having characters including large size, highly fused roots, upper molars of orthomegodont type, m1 anterior cap small and centrally located, and first pair of m1 reentrants on opposing sides, high crowns, and high value of dentine tract parameters. Based on the cladistics analysis, all seven species of Prosiphneus and P. eriksoni of Zanda form a monophyletic clade. P. eriksoni from Zanda, on the other hand, is nearly the terminal taxon of this clade. The appearance of P. eriksoni in Zanda represents a significant dispersal in the early Pliocene from its center of origin in north China and Mongolian Plateau, possibly via the Hol Xil-Qiangtang hinterland in northern Tibet. The fast evolving zokors are highly adapted to open terrains at a time when regional climates had become increasingly drier in the desert zones north of Tibetan Plateau during the late Miocene to Pliocene. The occurrence of this zokor in Tibet thus suggests a rather open steppe environment. Based on fossils of large mammals, we have formulated an "out of Tibet" hypothesis that suggests earlier and more primitive large mammals from the Pliocene of Tibet giving rise to the Ice Age megafauna. However, fossil records for large mammals are still too poor to evaluate whether they have evolved from lineages endemic to the Tibetan Plateau or were immigrants from outside. The superior record of small mammals is in a better position to address this question. With relatively dense age intervals and numerous localities in much of northern Asia, fossil zokors provide the first example of an "into Tibet" scenario--earlier and more primitive taxa originated from outside of the Tibetan Plateau and the

  19. [The pathogenic ecology research on plague in Qinghai plateau].

    Science.gov (United States)

    Dai, Rui-xia; Wei, Bai-qing; Li, Cun-xiang; Xiong, Hao-ming; Yang, Xiao-yan; Fan, Wei; Qi, Mei-ying; Jin, Juan; Wei, Rong-jie; Feng, Jian-ping; Jin, Xing; Wang, Zu-yun

    2013-12-01

    To study the pathogenic ecology characteristics of plague in Qinghai plateau. Applied molecular biology techniques, conventional technologies and geographic information system (GIS) to study phenotypic traits, plasmid spectrum, genotype, infected host and media spectrum etc.of 952 Yersinia pestis strains in Qinghai plateau plague foci, which were separated from different host and media in different regions during 1954 to 2012. The ecotypes of these strains were Qingzang plateau (91.49%, 871/952),Qilian mountain (6.41%, 61/952) and Microtus fuscus (1.26%, 12/952).83.6% (796/952) of these strains contained all the 4 virulence factors (Fr1, Pesticin1,Virulence antigen, and Pigmentation), 93.26% (367/392) were velogenic strains confirmed by virulence test.725 Yersinia pestis strains were separated from Qinghai plateau plague foci carried 9 kinds of plasmid, among which 713 strains from Marmot himalayan plague foci carried 9 kinds of plasmid, the Mr were 6×10(6), 7×10(6), 23×10(6), 27×10(6), 30×10(6), 45×10(6), 52×10(6), 65×10(6) and 92×10(6) respectively. 12 Yersinia pestis strains were separated from Microtus fuscus plague foci carried only 3 kinds of plasmid, the Mr were 6×10(6), 45×10(6), 65×10(6). Meanwhile, the strains carrying large plasmid (52×10(6), 65×10(6) and 92×10(6)) were only distributed in particular geographical location, which had the category property. The research also confirmed that 841 Yersinia pestis strains from two kinds of plague foci in Qinghai plateau had 11 genomovars. The strains of Marmot himalayan plague foci were given priority to genomovar 5 and 8, amounted to 611 strains, genomovar 8 accounted for 56.00% (471/841), genomovar 5 accounted for 23.07% (194/841). Besides, 3 new genomovars, including new 1(62 strains), new 2(52 strains), new 3(48 strains) were newly founded, and 12 strains of Microtus fuscus plague foci were genomovar 14. The main host and media of Qinghai plateau plague foci directly affected the spatial

  20. The Standardized Candle Method for Type II Plateau Supernovae

    Science.gov (United States)

    Olivares E., Felipe; Hamuy, Mario; Pignata, Giuliano; Maza, José; Bersten, Melina; Phillips, Mark M.; Suntzeff, Nicholas B.; Filippenko, Alexei V.; Morrel, Nidia I.; Kirshner, Robert P.; Matheson, Thomas

    2010-06-01

    In this paper, we study the "standardized candle method" using a sample of 37 nearby (redshift z color curves, and velocity curves. We find that the V-I color toward the end of the plateau can be used to estimate the host-galaxy reddening with a precision of σ(AV ) = 0.2 mag. The correlation between plateau luminosity and expansion velocity previously reported in the literature is recovered. Using this relation and assuming a standard reddening law (RV = 3.1), we obtain Hubble diagrams (HDs) in the BVI bands with dispersions of ~0.4 mag. Allowing RV to vary and minimizing the spread in the HDs, we obtain a dispersion range of 0.25-0.30 mag, which implies that these objects can deliver relative distances with precisions of 12%-14%. The resulting best-fit value of RV is 1.4 ± 0.1.

  1. Mantle structure beneath the western edge of the Colorado Plateau

    Science.gov (United States)

    Sine, C.R.; Wilson, D.; Gao, W.; Grand, S.P.; Aster, R.; Ni, J.; Baldridge, W.S.

    2008-01-01

    Teleseismic traveltime data are inverted for mantle Vp and Vs variations beneath a 1400 km long line of broadband seismometers extending from eastern New Mexico to western Utah. The model spans 600 km beneath the moho with resolution of ???50 km. Inversions show a sharp, large-magnitude velocity contrast across the Colorado Plateau-Great Basin transition extending ???200 km below the crust. Also imaged is a fast anomaly 300 to 600 km beneath the NW portion of the array. Very slow velocities beneath the Great Basin imply partial melting and/or anomalously wet mantle. We propose that the sharp contrast in mantle velocities across the western edge of the Plateau corresponds to differential lithospheric modification, during and following Farallon subduction, across a boundary defining the western extent of unmodified Proterozoic mantle lithosphere. The deep fast anomaly corresponds to thickened Farallon plate or detached continental lithosphere at transition zone depths. Copyright 2008 by the American Geophysical Union.

  2. Frequency of human toxocariasis in Jos, Plateau State, Nigeria

    Directory of Open Access Journals (Sweden)

    OO Ajayi

    2000-04-01

    Full Text Available The enzyme-linked immunosorbent assay (Elisa was used to examine sera of 104 children and adults in Jos, Plateau State, Nigeria for anti-toxocaral antibodies, out of which 31 (29.8% were reactive. The seropositive rates were 30.4% for adults, 29.6% for children, 34% for females and 25.9% for males. However, the differences were not significant by age and sex. A highly significant association (p 0.05.

  3. Landslide development within the Barlad Plateau of Eastern Romania

    Science.gov (United States)

    Niacsu, Lilian; Ionita, Ion

    2014-05-01

    The Barlad Plateau, extending about 8,230 square kilometers is considered as the most typical unit of the Moldavian Plateau of the Eastern Romania. The Miocene-Pliocene clay-sandy layers are inter-bedded with shallow sandstone and limestone seams. These sedimentary layers that have outcropped as a result of erosion are gently dipping toward S-SE in the form of a monocline. Landslides have been recognized as an important environmental threat in the major subunits of the Barlad Plateau, namely: Central Moldavian Plateau, Falciu Hills and Tutova Rolling Hills. Four main areas of monitoring landslides were explored such as successive aerial photographs of the 1960, 1970, 2005 and 2009 flights, repeated field surveys for a thorough reconnaissance of the study area, classical levelling work and GIS software applications as TNT Mips and Arc GIS. Also, the Caesium-137 technique has been used to get information on documenting sedimentation rates in some small catchments. Results have indicated that the landslide development is strongly controlled by the northern and western looking steep faces of cuestas, by changes of rock composition and by human impact. Also, it showed great pulses in conjunction with the rainfall distribution. For example, half of the Upper Barlad catchment that drains an area of 22,560 ha is covered by landslides. Furthermore, the active landslides amounted 11% of the total (2,317 ha) after the rainy 1968-1973 period and since 1982 under drier conditions they gradually limited to 444.0 ha (2% of the total).

  4. Evaluating first-year pine seedling survival plateau in Louisiana

    Science.gov (United States)

    Puskar N. Khana; Thomas J. Dean; Scott D. Roberts; Donald L. Grebner

    2016-01-01

    First-year seeding survival has been a continuing problem since the start of commercial pine plantation forestry in the 1950s. First-year survival of bare-root loblolly pine seedlings on intensively prepared sites in Louisiana has maintained a survival plateau between 79 to 89 percent with an average of about 82 percent. The specific objectives of this study were to...

  5. The Colorado Plateau: cultural, biological, and physical research

    Science.gov (United States)

    Cole, Kenneth L.; van Riper, Charles

    2004-01-01

    Stretching from the four corners of Arizona, New Mexico, Colorado, and Utah, the Colorado Plateau is a natural laboratory for a wide range of studies. This volume presents 23 original articles drawn from more than 100 research projects presented at the Sixth Biennial Conference of Research on the Colorado Plateau. This scientific gathering revolved around research, inventory, and monitoring of lands in the region. The book's contents cover management techniques for cultural, biological, and physical resources, representing collaborative efforts among federal, university, and private sector scientists and land managers. Chapters on cultural concerns cover benchmarks of modern southwestern anthropological knowledge, models of past human activity and impact of modern visitation at newly established national monuments, challenges in implementing the 1964 Wilderness Act, and opportunities for increased federal research on Native American lands. The section on biological resources comprises sixteen chapters, with coverage that ranges from mammalian biogeography to responses of elk at the urban-wildland interface. Additional biological studies include the effects of fire and grazing on vegetation; research on bald eagles at Grand Canyon and tracking wild turkeys using radio collars; and management of palentological resources. Two final chapters on physical resources consider a proposed rerouting of the Rio de Flag River in urban Flagstaff, Arizona, and an examination of past climate patterns over the Plateau, using stream flow records and tree ring data. In light of similarities in habitat and climate across the Colorado Plateau, techniques useful to particular management units have been found to be applicable in many locations. This volume highlights an abundance of research that will prove useful for all of those working in the region, as well as for others seeking comparative studies that integrate research into land management actions.

  6. Research on the slope spectrum of the Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A new concept dealing with digital analysis of loess terrain,slope spectrum,is presented and discussed in this paper,by introducing its characteristic,represen-tation and extracting method from DEMs. Using 48 geomorphological units in dif-ferent parts of the loess as test areas and 5 m-resolution DEMs as original test data,the quantitative depiction and spatial distribution of slope spectrum in China’s Loess Plateau have been studied on the basis of a series of carefully-designed experiments. In addition,initial experiment indicates a strong relationship between the slope spectrum and the loess landform types,displaying a potential importance of the slope spectrum in geomorphological studies. Based on the slope spectrums derived from the 25 m-resolution DEM data in whole loess terrain in northern part of Shaanxi,13 slope spectrum indices were extracted and integrated into a compre-hensive layer with image integration method. Based on that,a series of unsuper-vised classifications was applied in order to make a landform classification in northern Shaanxi Loess Plateau. Experimental results show that the slope spec-trum analysis is an effective method in revealing the macro landform features. A continuous change of slope spectrum from south to north in northern Shaanxi Loess Plateau shows an obvious spatial distribution of different loess landforms. This also proves the great significance of the slope spectrum method in describing the terrain roughness and landform evolution as well as a further understanding on landform genesis and spatial distribution rule of different landforms in the Loess Plateau.

  7. Stability of alpine meadow ecosystem on the Qinghai- Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    ZHOU Huakun; ZHOU Li; ZHAO Xinquan; LIU Wei; LI Yingnian; GU Song; ZHOU Xinmin

    2006-01-01

    The meadow ecosystem on the Qinghai-Tibetan Plateau is considered to be sensitive to climate change. An understanding of the alpine meadow ecosystem is therefore important for predicting the response of ecosystems to climate change. In this study, we use the coefficients of variation (Cv) and stability (E) obtained from the Haibei Alpine Meadow Ecosystem Research Station to characterize the ecosystem stability. The results suggest that the net primary production of the alpine meadow ecosystem was more stable (Cv = 13.18%) than annual precipitation (Cv = 16.55%) and annual mean air temperature (Cv = 28.82%). The net primary production was insensitive to either the precipitation (E = 0.0782) or air temperature (E = 0.1113). In summary, the alpine meadow ecosystem on the Qinghai- Tibetan Plateau is much stable. Comparison of alpine meadow ecosystem stability with other five natural grassland ecosystems in Israel and southern African indicates that the alpine meadow ecosystem on the Qinghai-Tibetan Plateau is the most stable ecosystem. The alpine meadow ecosystem with relatively simple structure has high stability, which indicates that community stability is not only correlated with biodiversity and community complicity but also with environmental stability. An average oscillation cycles of 3―4 years existed in annual precipitation, annual mean air temperature, net primary production and the population size of consumers at the Haibei natural ecosystem. The high stability of the alpine meadow ecosystem may be resulting also from the adaptation of the ecosystem to the alpine environment.

  8. Several characteristics of contemporary climate change in the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    朱文琴; 陈隆勋; 周自江

    2001-01-01

    Characteristics of contemporary climate change in the Tibetan Plateau have been investigated based on the observational data of monthly mean air temperature, monthly mean maximum and minimum air temperatures, and precipitation amount at 217 stations in the Plateau and its adjacent areas in 1951-1998, in which the temperature data at Lhasa, Lanzhou, Kunming and Chengdu were extended to a period of 1935-1950. The following conclusions can be drawn. (1) The air temperature in the Tibetan Plateau decreased from the 1950s to the 1960s, afterwards it began warming up to the 1990s. The data at the Lhasa Station beginning from 1935 have indicated that the air temperature at the station was the highest in the 1940s, then it became cooling until the 1960s. After the 1960s, it began warming until the 1990s. However, the air temperature at Lhasa in the 1990s still did not reach as high as in the 1940s. (2) Since the 1960s, there has existed a cooling belt below 3000 m altitude above sea level, which is located in ea

  9. Soil Erosion Study on the Chinese Loess Plateau

    Science.gov (United States)

    Hu, Yaxian; Guo, Shengli; Kuhn, Nikolaus

    2017-04-01

    The Chinese Loess Plateau, because of its highly erodible loess soils and hilly topography, has been extensively studied by soil scientists and geomorphologists. As a research hotspot, there are five national-level field stations across the Loess Plateau, with hundreds of erosion plots set up with various sizes, lengths, slope angles and vegetation covers. In addition, huge indoor rain simulation facilities exist in in different institutes which can provide rainfall simulations under a wide range of controlled conditions. Consequently, national-level restoration projects have achieved tremendous improvements in curbing soil erosion and improving regional agro-ecosystem, mostly by afforestation and soil rehabilitation. However, when implementing the advanced techniques and models that have been widely applied in the rest of the world, there are often regional considerations, which demand new approaches to overcome. One example are the unintentional impacts of restoration efforts, such as the establishment of apple orchards. Over 20 years, they have caused an increase in soil erodibility and lowered local ground water levels. Neither before the introduction of this landscape rehabilitation technique, nor now, has the impact of intensive fruit production been systematically studied, despite lending itself to systematic experiments. The lack of research is attributed to the general idea that trees protect soils and improve environmental services. This presentation identifies several such specific regional environmental issues associated with soil erosion on the Loess Plateau and discusses strategies to avoid missing important research questions.

  10. Spatial variation of reference crop evapotranspiration on Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    Yong-hong YANG; Zhan-yu ZHANG; Xin-yi XIANG

    2009-01-01

    This study is based on meteorological observation data collected at 38 weather stations on the Tibetan Plateau over several decades. Daily reference crop evapotranspiration (ET0) was calculated with the FAO-56 standard Penman-Monteith formula. A test of normality was performed with Statistica 6.0 software, isotropic and anisotropic semi-variogram analysis was conducted with the GS+ (geostatistics for the environmental sciences) system for Windows 7.0, and the characteristics of spatial variation of daily ET0 were obtained. The following results can be obtained: Daily ETo for different periods on the Tibetan Plateau are distributed normally; Except for daily ETo in the E-W (east-west) direction in the summer, which showed a slight negative correlation with distance change, the Moran's indexes of daily ET0 for different periods in all directions on the Tibetan Plateau within a 100-km distance were positive, demonstrating a positive correlation with distance change; Variograms of daily ET0 in June, the dry season, the wet season, as well as annual average daily ET0 fit well with the Gaussian model; A variogram of daily ET0 in December fit well with the exponential model; Variograms of daily ET0 for the four seasons fit well with the linear with sill model.

  11. Plateau Inflation in $R$-parity Violating MSSM

    CERN Document Server

    Chakravarty, Girish Kumar; Lambiase, Gaetano; Mohanty, Subhendra

    2016-01-01

    Inflation with plateau potentials give the best fit to the CMB observables as they predict tensor to scalar ratio stringently bounded by the observations from Planck and BICEP2/Keck. In supergravity models it is possible to obtain plateau potentials for scalar fields in the Einstein frame which can serve as the inflation potential by considering higher dimensional Planck suppressed operators and by the choice of non-canonical K\\"ahler potentials. We construct a plateau inflation model in MSSM where the inflation occurs along a sneutrino-Higgs flat direction. A hidden sector Polonyi field is used for the breaking of supersymmetry at the end of the inflation. The SUSY breaking results in a TeV scale gravitino mass and scalar masses and gives rise to bilinear and triliear couplings of scalars which can be tested at the LHC. The sneutrino inflation field can be observed at the LHC as a TeV scale diphoton resonance like the one reported by CMS and ATLAS.

  12. Path of Social Construction in Northwest Sichuan Plateau Pastoral Area

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    On the basis of main contents of social construction and key points of construction,this paper analyzes features of conditions of northwest Sichuan plateau pastoral area.The social construction at current stage mainly includes social cause in narrow sense,and social management at meso-level.The northwest Sichuan plateau pastoral area is faced with the best policy and development opportunity.However,there are still many weak aspects.Firstly,social structure is not coordinated with economic structure.Secondly,social construction ability of grass-roots government is weak.Thirdly,the ability to respond to public demands is low.Fourthly,there is a big gap in availability of basic public service.Finally,it presents path selection for social construction of northwest Sichuan plateau pastoral area:strengthen social construction ability of grass-roots government;promote social construction with livelihood projects as key projects;boost social construction taking advantage of ecological construction;develop basic public service with the aid of external forces;intensify evaluation system for supervision of social construction works.

  13. River discharge changes in the Qinghai-Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Annual mean discharge data of the five large rivers in the exorheic region of the Qinghai-Tibet Plateau from 1956 to 2000 are analyzed for trends with the Mann-Kendall nonparametric trend test. The results reveal that though in general no increasing trends exist in the total river discharges, significant regional differences of river discharge exist, reflecting the decreasing trends of discharge in the Yellow River and the Tongtian River (upper Changjiang River), an increasing trend in Yalong River, and inverted change in the Lancang River and Yarlung Zangbo River. Based on analyses of the seasonal discharge, it is found that climatic change had a significant effect on the seasonal variation of river discharge in the Qinghai-Tibet Plateau. In spring (from March to May) the discharge increased significantly, especially in the source area of the Yellow River. Together with the analyses on data of the mean temperature in the Northern Hemisphere and climatic data within the river basins, the relationship between discharges and mean temperature of the Northern Hemisphere is explored, which indicates that there is no increase in the stream discharge in the Qinghai-Tibet Plateau with global warming. It is probably the increasing evaporation, caused by rising temperature that offsets the hydrological effect of increasing precipitation.

  14. Plateau inflation in R-parity violating MSSM

    Science.gov (United States)

    Chakravarty, Girish Kumar; Dey, Ujjal Kumar; Lambiase, Gaetano; Mohanty, Subhendra

    2016-12-01

    Inflation with plateau potentials give the best fit to the CMB observables as they predict tensor to scalar ratio stringently bounded by the observations from Planck and BICEP2/Keck. In supergravity models it is possible to obtain plateau potentials for scalar fields in the Einstein frame which can serve as the inflation potential by considering higher dimensional Planck suppressed operators and by the choice of non-canonical Kähler potentials. We construct a plateau inflation model in MSSM where the inflation occurs along a sneutrino-Higgs flat direction. A hidden sector Polonyi field is used for the breaking of supersymmetry after the end of the inflation. The proper choice of superpotential leads to strong stabilization of the Polonyi field, mZ2 ≫m3/22, which is required to solve the cosmological moduli problem. Also, the SUSY breaking results in a TeV scale gravitino mass and scalar masses and gives rise to bilinear and trilinear couplings of scalars which can be tested at the LHC. The sneutrino inflation field can be observed at the LHC as a TeV scale diphoton resonance like the one reported by CMS and ATLAS.

  15. The Relevant Analysis on the Stop Time in Winter and Times of Plateau and the Index in Early Days for Garrisonned Plateau Constructors

    Institute of Scientific and Technical Information of China (English)

    Yuan Zhencai; Zhang Xuefeng; Deng Yunqing; Wu Chengkui; Cao Ruiling; Peng Quansheng

    2007-01-01

    Objective: Study the influence of the stop time in winter, times of plateau on the index in early days for plateau constructors meet; Method: Is it participate in plateau construction of 2002-2004 to choose, enter into the plateau again of 2003-2005 practise clothes finish to mate 326 materials "physical examination in front of the worker", which is passed in Nanshankou Hospital in early days, divided into 3 groups according to the difference of year for the physical examination, examine by leaning towards relevant analytical methods; Result: (1) In the situation of day controlling about the stop time in winter, times of garrison in plateau and blood and oxygen saturation lever ( SaO2 ), the systolic pressure (sBP) is presented and shouldered relevantly winter to control. Present positive correlation with the value of hemoglobin (Hb) ; (2) It is stopped that in case of controlling and is garrisoned in the number of times of plateau in winter day and blood and oxygen saturation lever (SaO2) to present positive correlation. Present and shoulder with the hemoglobin (Hb) relevantly. Conclusion: In order to ensure the health of plateau constructors to the maximum extent, should try one's best to reduce the number of times of returning to the plateau in possible cases. At the same time each one constructs for year and returns to the time that the hinterland concentrates rest should be on above 90 days.

  16. Validation and Application of Reanalysis Temperature Data over the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    ZOU Han; ZHU Jinhuan; ZHOU Libo; LI Peng; MA Shupo

    2014-01-01

    The Tibetan Plateau has substantial impacts on the weather and climate of the Northern Hemisphere, due in large part to the thermal eff ects of the plateau surface. Surface temperature over the Tibetan Plateau is the most important parameter in determining these thermal eff ects. We present a method for verifying widely used reanalysis temperature products from NCEP-R2, ERA-Interim, and JRA-25 over the Tibetan Plateau, with the aim of obtaining a reliable picture of surface temperature and its changes over the plateau. Reanalysis data are validated against the topography elevation, satellite observations, and radiosonde data. ERA-Interim provides the most reliable estimates of Tibetan Plateau surface temperature among these three reanalyses. We therefore use this dataset to study the climatology and trends of surface temperature over the Tibetan Plateau. ERA-Interim data indicate a dramatic warming over the Tibetan Plateau from 1979 to 2010, with warming rates of 0.33℃per decade in annual mean temperature, 0.22℃per decade in summer and 0.47℃ per decade in winter mean temperatures. Comparison with the results of previous studies suggests that surface warming over the Tibetan Plateau has accelerated during the past 30 years. This warming is distributed heterogeneously across the Tibetan Plateau, possibly due to topographic eff ects.

  17. Validation and application of reanalysis temperature data over the Tibetan Plateau

    Science.gov (United States)

    Zou, Han; Zhu, Jinhuan; Zhou, Libo; Li, Peng; Ma, Shupo

    2014-02-01

    The Tibetan Plateau has substantial impacts on the weather and climate of the Northern Hemisphere, due in large part to the thermal effects of the plateau surface. Surface temperature over the Tibetan Plateau is the most important parameter in determining these thermal effects. We present a method for verifying widely used reanalysis temperature products from NCEP-R2, ERA-Interim, and JRA-25 over the Tibetan Plateau, with the aim of obtaining a reliable picture of surface temperature and its changes over the plateau. Reanalysis data are validated against the topography elevation, satellite observations, and radiosonde data. ERA-Interim provides the most reliable estimates of Tibetan Plateau surface temperature among these three reanalyses. We therefore use this dataset to study the climatology and trends of surface temperature over the Tibetan Plateau. ERA-Interim data indicate a dramatic warming over the Tibetan Plateau from 1979 to 2010, with warming rates of 0.33°C per decade in annual mean temperature, 0.22°C per decade in summer and 0.47°C per decade in winter mean temperatures. Comparison with the results of previous studies suggests that surface warming over the Tibetan Plateau has accelerated during the past 30 years. This warming is distributed heterogeneously across the Tibetan Plateau, possibly due to topographic effects.

  18. Climatology of monsoon precipitation over the Tibetan Plateau from 13-year TRMM observations

    Science.gov (United States)

    Aijuan, Bai; Guoping, Li

    2016-10-01

    Based on the 13-year data from the Tropical Rainfall Measuring Mission (TRMM) satellite during 2001-2013, the influencing geographical location of the Tibetan Plateau (Plateau) monsoon is determined. It is found that the domain of the Plateau monsoon is bounded by the latitude between 27° N and 37° N and the longitude between 60° E and 103° E. According to the annual relative precipitation, the Plateau monsoon can be divided into three sections: the Plateau winter monsoon (PWM) over Iran and Afghanistan, the Plateau summer monsoon (PSM) over the central Plateau, and the transiting zone of the Plateau monsoon (TPM) over the south, west, and east edges of the Plateau. In PWM and PSM, the monsoon climatology has a shorter rainy season with the mean annual rainfall of less than 800 mm. In TPM, it has a longer rainy season with the mean annual rainfall of more than 1800 mm. PWM experiences a single-peak monthly rainfall with the peak during January to March; PSM usually undergoes a multi-peak pattern with peaks in the warm season; TPM presents a double-peak pattern, with a strong peak in late spring to early summer and a secondary peak in autumn. The Plateau monsoon also characterizes an asymmetrical seasonal advance of the rain belt. In the east of the Plateau, the rain belt migrates in a south-north orientation under the impact of the tropical and subtropical systems' oscillation. In the west of the Plateau, the rain belt advances in an east-west direction, which is mainly controlled by the regional Plateau monsoon.

  19. Analysis of the structure of different Tibetan Plateau vortex types

    Science.gov (United States)

    Feng, Xinyuan; Liu, Changhai; Fan, Guangzhou; Zhang, Jie

    2017-06-01

    Knowledge of the structure of the Tibetan Plateau vortex (TPV) is of considerable importance for understanding the generation and development mechanisms of this mesoscale system. However, our understanding of vortex structures and our ability to classify them on a physical basis is limited due to insufficient observations. The highresolution new-generation NCEP-CFSR (Climate Forecast System Reanalysis) dataset is used in the present paper to investigate the general structural features of various types of mature TPV through classification and composite structure analysis. Results indicate that the dynamic and thermodynamic structures show regional and seasonal dependency, as well as being influenced by attributes of translation, associated precipitation, and the South Asian high (SAH). The common precipitating TPV (type I), frequently occurring in the west-east-oriented zonal region between 33° and 36°N, is a notably low-level baroclinic and asymmetric system. It resides within a large-scale confluent zone and preferentially travels eastward, potentially moving out of the plateau. The heavy rain vortex (type II) corresponds to a deep vortex circulation occurring in midsummer. The low-level baroclinic sub-category (type IIa) is associated with a low-level jet and mainly originates in the area 32°-35°N, 86°-94°E, preferentially moving east of 90°E and even away from the plateau; meanwhile, the nearly upright sub-category (type IIb), which has a cold center at low levels and a warm center at mid-upper levels, is a quasi-stationary and quasi-symmetric system favorably occurring west of 92°E. A western-pattern SAH exists in the upper troposphere for these two sub-categories. The springtime dry vortex in the western plateau (type III) is warm and shallow (approximately 100 hPa deep), and zonal circulation dominates the large-scale environmental flows in the middle and upper troposphere. The precipitating vortex in the southern plateau occurring during July

  20. Agulhas Plateau and Mozambique Ridge: Two LIPS of a Kind?

    Science.gov (United States)

    Uenzelmann-Neben, G.; Gohl, K.; Parsiegla, N.

    2008-12-01

    The seaway south of South Africa represents a critical gateway within the global ocean circulation. Here, warm surface and cold deep and bottom water masses meet and lead to a transfer of heat and salt between the Indian and Atlantic Oceans. This transfer maintains the global thermohaline circulation. The paths of the oceanic currents are strongly influenced by the seafloor topography observed in this region. Thus, the tectonic evolution of the South African continental margin and the gateway starting in Cretaceous times are of major importance in order to understand the evolution of the current system and the transition from the Greenhouse to the Icehouse world. The gateway itself is characterized by the Agulhas Plateau, which has been postulated to originate in the interaction of the Bouvet Hotspot and a triple junction and thus to fall within the world-wide suite of Large Igneous Provinces [Gohl and Uenzelmann-Neben, 2001; Parsiegla, et al., 2008; Uenzelmann-Neben, et al., 1999]. A similar structure has been identified for the crust of the southern Mozambique Ridge [Gohl, et al., submitted]. This raises the question whether those two LIP events were related, whether their emplacement happened at the same time and how they tie in with other LIP events observed in Late Cretaceous times such as the formation or the Kerguelen LIP. Furthermore, we may speculate on the effect those magmatic events had on the evolution of both oceanic currents and the climate. Similarities as well as differences in crustal structure and evolution and later sedimentary development will be presented for those two structures based on seismic refraction and reflection data. References: Gohl, K. and G. Uenzelmann-Neben (2001), The crustal role of the Agulhas Plateau, southwest Indian Ocean: Evidence from seismic profiling, Geophysical Journal International, 144, 632-646. Gohl, K., et al. (submitted), Is the Mozambique Ridge related to the Agulhas Plateau Large Igneous Province?, Geophysical

  1. Early Human Occupation on the Northeast Tibetan Plateau

    Science.gov (United States)

    Rhode, D.; Madsen, D.; Brantingham, P.; Perrault, C.

    2010-12-01

    The Tibetan Plateau presents great challenges for human occupation: low oxygen, high ultraviolet radiation, harsh seasonal climate, low overall biological productivity. How and when early humans were able to cope physiologically, genetically, and behaviorally with these extremes is important for understanding the history of human adaptive flexibility. Our investigations of prehistoric human settlement on the northeast Tibetan Plateau focus on (a) establishing well-dated evidence for occupation of altitudes >3000 m, (b) the environmental context of high altitude adaptation, and (c) relations of hunting and pastoralism to lower-altitude agrarian systems. We observe two major prehistoric settlement patterns in the Qinghai Lake area. The earliest, ~15,000-7500 yr old, consists of small isolated firehearths with sparse associated stone tools and wild mammal remains (1). Numerous hearths often occur in the same localities, indicating repeated short-duration occupations by small hunting parties. A second pattern, ~9000-4000 yr old, was established during the Holocene climatic optimum. These sites represent prolonged seasonal residential occupation, containing dark anthropogenic midden, hearth and pit constructions, abundant stone tools, occasional ceramics, and abundant diverse faunal remains (including medium-large mammals but lacking domestic sheep/yak)(2). These Plateau-margin base camps allowed greater intensity of use of the high Plateau. Residential occupation was strongly influenced by nearby lower-altitude farming communities; development of the socioeconomic landscape along the Yellow River likely played at least as great a role in Plateau occupation patterns as did Holocene environmental changes. Holocene vegetation changes in the NE Tibetan Plateau have been attributed to climate (3) or anthropogenic modification (4). Our results document changes in shrub/tree presence from ~12,000-4000 BP, similar to pollen records, that likely reflect climate rather than

  2. Plateau iris Íris em platô

    Directory of Open Access Journals (Sweden)

    Alberto Diniz Filho

    2008-10-01

    Full Text Available The term plateau iris was first coined in 1958 to describe the iris configuration of a patient. Two years later the concept of plateau iris was published. In 1977, the plateau iris configuration was classically defined as presurgical changes of an eye with a relative normal central anterior chamber depth, flat iris by conventional biomicroscopy, but displaying an extremely narrow or closed angle on gonioscopic examination. On the other hand, the plateau iris syndrome was defined as an acute glaucoma crisis in one eye with a relative normal central anterior chamber depth and patent iridotomy on direct examination, presenting angle closure confirmed by gonioscopic examination after mydriasis. In 1992, the anatomic aspects of plateau iris were studied using ultrasound biomicroscopy. Finally, plateau iris has been considered an anatomic variant of iris structure in which the iris periphery angulates sharply forward from its insertion point and then again angulates sharply and centrally backward, along with an anterior positioning of the ciliary processes seen on ultrasound biomicroscopy. The clinical treatment of plateau iris syndrome is carried out with topical use of pilocarpine. However, the definitive treatment should be fulfilled by performing an argon laser peripheral iridoplasty.O termo íris em platô foi primeiramente inventado em 1958 para descrever a configuração da íris de um paciente. Dois anos depois o conceito de íris em platô foi publicado. Em 1977, a configuração de íris em platô foi classicamente definida como alterações pré-cirúrgicas de um olho com uma profundidade de câmara anterior relativamente normal, íris plana pela biomicroscopia convencional, mas mostrando um ângulo extremamente estreito ou fechado pela gonioscopia. Por outro lado, a síndrome de íris em platô foi definida como uma crise de glaucoma agudo em um olho com uma profundidade de câmara anterior relativamente normal e uma iridectomia patente ao

  3. The system of physico-geographical regions of the Qinghai-Xizang (Tibet) Plateau

    Institute of Scientific and Technical Information of China (English)

    郑度

    1996-01-01

    The Qinghai-Xizang Plateau is a unique physico-geographical region on the earth. As a whole, the spatial differentiation of physico-geographical regions of the plateau is mainly determined by topographic configuration and atmospheric circulation, warm and humid in the southeast, cold and arid in the northwest. The natural landscapes apppear in the following succession: forest → meadow → steppe → desert. The system of physico-geographical regions of the plateau is demarcated on the principle of bio-climate or the principle of three dimension zonality. Based on the thermal conditions, moisture regimes and variation in landform the Qinghai-Xizang Plateau is sequentially demarcated. The duration of mean daily temperature above 10℃ is the principal index, the subsidiary criterion is mean temperature of the warmest month, two temperature belts may be divided: plateau subpolar and plateau temperate. Annual aridity is taken as the principal index, subordinated by annual precipitation. Four moisture regional

  4. Using a Multi-Method Approach to Examine Social-Ecological Vulnerability to Climate Change and Natural Resource Policies on the Tibetan Plateau

    Science.gov (United States)

    Klein, J.; Hopping, K. A.; Yeh, E.; Nyima, Y.; Galvin, K.; Boone, R.; Dorje, T.; Ojima, D. S.

    2012-12-01

    Pastoralists and ecosystems on the Tibetan Plateau are facing a suite of novel stresses. Temperatures are increasing several times more than the global average. The frequency and severity of severe snowstorms, which lead to critical losses of livestock, are also increasing. Pastoralists are also experiencing changes to their livelihood activities, including reduced mobility and severe grazing restrictions. We are using interdisciplinary frameworks and methods that integrate results from a multifactor ecological experiment, household interviews, remote sensing, and a coupled ecosystem and household decision-making model to examine herder and ecosystem vulnerability to climate change and extreme weather events (snow disasters) within the context of changing natural resource management policies in China. The fully factorial ecological experiment includes two climate changes (warming and spring snow additions) and two types of grazing (yak and pika) that are being affected by current policy. We established the experiment in 2008 within the Tibet Autonomous Region. We are monitoring microclimate, vegetation, nutrient availability, ecosystem carbon fluxes and stable isotope signatures of select plant species. Through this experiment, we are investigating the sensitivity of the system, whether it can cross critical thresholds, and how resilient this system may be to predicted future climate and land use changes. Semi-structured, in-depth interviews on indigenous knowledge and vulnerability complement the ecological experimental work. We are asking herders about climate and ecological change and their drivers and are also conducting interviews on vulnerability to snow disasters across a three site, 300-500mm precipitation gradient. We are using remote sensing to identify biophysical landscape change over time. To integrate our ecological and social findings, we are coupling the Savanna ecosystem model to the DECUMA agent-based pastoral household model. Our results to date

  5. Spiny Neurons of Amygdala, Striatum and Cortex Use Dendritic Plateau Potentials to Detect Network UP States

    Directory of Open Access Journals (Sweden)

    Katerina D Oikonomou

    2014-09-01

    Full Text Available Spiny neurons of amygdala, striatum, and cerebral cortex share four interesting features: [1] they are the most abundant cell type within their respective brain area, [2] covered by thousands of thorny protrusions (dendritic spines, [3] possess high levels of dendritic NMDA conductances, and [4] experience sustained somatic depolarizations in vivo and in vitro (UP states. In all spiny neurons of the forebrain, adequate glutamatergic inputs generate dendritic plateau potentials (dendritic UP states characterized by (i fast rise, (ii plateau phase lasting several hundred milliseconds and (iii abrupt decline at the end of the plateau phase. The dendritic plateau potential propagates towards the cell body decrementally to induce a long-lasting (longer than 100 ms, most often 200 – 800 ms steady depolarization (~20 mV amplitude, which resembles a neuronal UP state. Based on voltage-sensitive dye imaging, the plateau depolarization in the soma is precisely time-locked to the regenerative plateau potential taking place in the dendrite. The somatic plateau rises after the onset of the dendritic voltage transient and collapses with the breakdown of the dendritic plateau depolarization. We hypothesize that neuronal UP states in vivo reflect the occurrence of dendritic plateau potentials (dendritic UP states. We propose that the somatic voltage waveform during a neuronal UP state is determined by dendritic plateau potentials. A mammalian spiny neuron uses dendritic plateau potentials to detect and transform coherent network activity into a ubiquitous neuronal UP state. The biophysical properties of dendritic plateau potentials allow neurons to quickly attune to the ongoing network activity, as well as secure the stable amplitudes of successive UP states.

  6. Continental Dynamics in High Tibetan Plateau: Normal Faulting Type Earthquake Activities and Mechanisms

    Institute of Scientific and Technical Information of China (English)

    Xu Jiren; Zhao Zhixin

    2009-01-01

    Various earthquake fault types were analyzed for this study on the crust movement in the high region of the Tibetan plateau by analyzing mechanism solutions and stress fields. The results show that a lot of normal faulting type earthquakes are concentrated in the central High Tibetan plateau. Many of them are nearly perfect normal fault events. The strikes of the fault planes of normal faulting earthquakes are almost in an N-S direction based on the analyses of the Wulff stereonet diagrams of fault plane solutions. It implies that the dislocation slip vectors of the normal faulting type events have quite great components in the E-W direction. The extensions probably are an eastward extensional motion, being mainly a tectonic active regime in the plateau altitudes. The tensional stress in the E-W or NWW-SEE direction predominates earthquake occurrences in the normal event region of the central plateau. The eastward extensional motion in the high Tibetan plateau is attributable to the gravitational collapse of the high plateau and the eastward extrusion of hotter mantle materials beneath the east boundary of the plateau. Extensional motions from the relaxation of the topography and/or gravitational collapse in the high plateau hardly occurred along the N-S direction. The obstruction for the plateau to move eastward is rather weak.

  7. Posterior Slope of the Tibia Plateau in Malaysian Patients Undergoing Total Knee Replacement

    Directory of Open Access Journals (Sweden)

    R Yoga

    2009-05-01

    Full Text Available The posterior slope of the tibial plateau is an important feature to preserve during knee replacement. The correct slope aids in the amount of flexion and determines if the knee will be loose on flexion. This is a study on the posterior tibial plateau slope based on preoperative and postoperative radiographs of 100 consecutive patients who had total knee replacements. The average posterior slope of the tibia plateau was 10.1 degrees. There is a tendency for patients with higher pre-operative posterior tibial plateau slope to have higher post-operative posterior tibial plate slope.

  8. Review of Digital Elevation Model (DEM) Based Research on China Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    Tang Guo'an; Ge Shanshan; Li Fayuan; Zhou Jieyu

    2005-01-01

    The Loess Plateau is one of the hot research areas for its specific geographical features. In resent years, with the establishment of national multi-scale DEMs and the perfection of DEM based digital terrain analysis methods, new thoughts and methodologies have been constructed for the Loess Plateau research. This paper introduces the characteristics of DEM data, analyses the development stages of DEM applied in the Loess Plateau research, and discusses its further possible research direction. More discussions are focused on slope spectrum and its concept, as well as the significance in the Loess Plateau research.

  9. FINAL FRONTIER AT HANFORD TACKLING THE CENTRAL PLATEAU

    Energy Technology Data Exchange (ETDEWEB)

    GERBER MS

    2008-03-04

    The large land area in the center of the vast Department of Energy (DOE) Hanford Site in southeast Washington State is known as 'the plateau'--aptly named because its surface elevations are 250-300 feet above the groundwater table. By contrast, areas on the 585-square mile Site that border the Columbia River sit just 30-80 feet above the water table. The Central Plateau, which covers an ellipse of approximately 70 square miles, contains Hanford's radiochemical reprocessing areas--the 200 East and 200 West Areas--and includes the most highly radioactive waste and contaminated facilities on the Site. Five 'canyons' where chemical processes were used to separate out plutonium (Pu), 884 identified soil waste sites (including approximately 50 miles of solid waste burial trenches), more than 900 structures, and all of Hanford's liquid waste storage tanks reside in the Central Plateau. (Notes: Canyons is a nickname given by Hanford workers to the chemical reprocessing facilities. The 177, underground waste tanks at Hanford comprise a separate work scope and are not under Fluor's management). Fluor Hanford, a DOE prime cleanup contractor at the Site for the past 12 years, has moved aggressively to investigate Central Plateau waste sites in the last few years, digging more than 500 boreholes, test pits, direct soil 'pushes' or drive points; logging geophysical data sets; and performing electrical-resistivity scans (a non-intrusive technique that maps patterns of sub-surface soil conductivity). The goal is to identify areas of contamination areas in soil and solid waste sites, so that cost-effective and appropriate decisions on remediation can be made. In 2007, Fluor developed a new work plan for DOE that added 238 soil waste-site characterization activities in the Central Plateau during fiscal years (FYs) 2007-2010. This number represents a 50 percent increase over similar work previously done in central Hanford. Work Plans are

  10. Re-evaluating the 1940s CO2 plateau

    Science.gov (United States)

    Bastos, Ana; Ciais, Philippe; Barichivich, Jonathan; Bopp, Laurent; Brovkin, Victor; Gasser, Thomas; Peng, Shushi; Pongratz, Julia; Viovy, Nicolas; Trudinger, Cathy M.

    2016-09-01

    The high-resolution CO2 record from Law Dome ice core reveals that atmospheric CO2 concentration stalled during the 1940s (so-called CO2 plateau). Since the fossil-fuel emissions did not decrease during the period, this stalling implies the persistence of a strong sink, perhaps sustained for as long as a decade or more. Double-deconvolution analyses have attributed this sink to the ocean, conceivably as a response to the very strong El Niño event in 1940-1942. However, this explanation is questionable, as recent ocean CO2 data indicate that the range of variability in the ocean sink has been rather modest in recent decades, and El Niño events have generally led to higher growth rates of atmospheric CO2 due to the offsetting terrestrial response. Here, we use the most up-to-date information on the different terms of the carbon budget: fossil-fuel emissions, four estimates of land-use change (LUC) emissions, ocean uptake from two different reconstructions, and the terrestrial sink modelled by the TRENDY project to identify the most likely causes of the 1940s plateau. We find that they greatly overestimate atmospheric CO2 growth rate during the plateau period, as well as in the 1960s, in spite of giving a plausible explanation for most of the 20th century carbon budget, especially from 1970 onwards. The mismatch between reconstructions and observations during the CO2 plateau epoch of 1940-1950 ranges between 0.9 and 2.0 Pg C yr-1, depending on the LUC dataset considered. This mismatch may be explained by (i) decadal variability in the ocean carbon sink not accounted for in the reconstructions we used, (ii) a further terrestrial sink currently missing in the estimates by land-surface models, or (iii) LUC processes not included in the current datasets. Ocean carbon models from CMIP5 indicate that natural variability in the ocean carbon sink could explain an additional 0.5 Pg C yr-1 uptake, but it is unlikely to be higher. The impact of the 1940-1942 El Niño on the

  11. DYNAMICS OF BRÂGLEZ RIVERBED (SOMEŞAN PLATEAU

    Directory of Open Access Journals (Sweden)

    V. ARGHIUŞ

    2012-03-01

    Full Text Available Dynamics of Brâglez Riverbed (Someşan Plateau. The main left tributaries of Someş along Surduc – Jibou sector (Brâglez, Almaş and Agrij, are characterized by the presence of obvious processes of lateral and vertical erosion at the level of the riverbeds. The field observations, as well as the position of these rivers and their catchment areas in the neighborhood of the lower Someş subsidence area, would easily be grounds for explaining the riverbed processes as caused by an unstable fluvial base level. More precisely, this base level would be moving downwards under the influence of subsidence movements of Tisa Plain or even because of the subsidence affecting Guruslău Basin. Starting from these more or less speculative deductions, this paper aims at checking and confirming the above-mentioned explanations or finding other causes for the dynamics of riverbed processes. In this sense, we analysed a correlation between the drainage in the catchment area and at the level of the riverbeds, on one hand, and the riverbed geomorphological processes, on the other hand. Brâglez River (in western Someşan Plateau will be considered as a study case, as it provides an accelerated dynamics of riverbed processes. This situation will be compared with the one in the eastern part of the same plateau, where rivers like Borşa, Luna or Lujerdiu do not present obvious riverbed processes despite the similar climatic and geological conditions.

  12. Late Cretaceous tectonic framework of the Tibetan Plateau

    Science.gov (United States)

    Wu, Zhenhan; Barosh, Patrick J.; Ye, Peisheng; Hu, Daogong

    2015-12-01

    New research, coupled with previous data, reveals the Late Cretaceous paleo-geography, and related paleo-tectonic movement of the Tibetan Plateau. A vast ocean, the Neo-Tethys Ocean, perhaps as wide as ∼7000 km, existed between the Indian and Eurasian Continental Plates in the early Late Cretaceous. In addition, a Himalaya Marginal Sea lay along the border of the Indian Plate and other marginal seas were present to the north in both the southern Lhasa and southwestern Tarim Blocks. Northward subduction of the Neo-Tethys Oceanic Plate along the Yalung-Zangbu Suture closed most of the ocean and led to intensive thrusting, tight folding, magmatic plutonism and volcanic eruptions in the central plateau to the north. A magmatic arc up to 500 km wide formed across the southern margin of the continental plate in central Tibet and its varying granitic composition appears to reflect the depth to the subducted plate and define its geometry. A series of large, chiefly north-dipping thrust systems also developed across central Tibet. These include thrusts along the Yalung-Zangbu and Bangong-Nujiang Sutures, the North Gangdese and North Lhasa Thrusts in the Lhasa Block, the Qiangtang and North Tangula Thrusts in the Qiangtang block, the Hoh-Xil and Bayan Har Thrusts in the Hoh-Xil Block, as well as the sinistral-slip South Kunlun and Altyn Tagh Faults in northern Tibet. Uplifts formed above the hanging walls of the major thrusts and their eroded debris formed thick red-beds in basins below them. The central Tibetan Plateau maintained a low elevation and coastal vegetation was dominant during the Late Cretaceous.

  13. Resistivity plateau and extreme magnetoresistance in LaSb

    Science.gov (United States)

    Tafti, F. F.; Gibson, Q. D.; Kushwaha, S. K.; Haldolaarachchige, N.; Cava, R. J.

    2016-03-01

    Time reversal symmetry (TRS) protects the metallic surface modes of topological insulators (TIs). The transport signature of such surface states is a plateau that arrests the exponential divergence of the insulating bulk with decreasing temperature. This universal behaviour is observed in all TI candidates ranging from Bi2Te2Se to SmB6. Recently, extreme magnetoresistance (XMR) has been reported in several topological semimetals which exhibit TI universal resistivity behaviour only when breaking time reversal symmetry, a regime where TIs theoretically cease to exist. Among these materials, TaAs and NbP are nominated as Weyl semimetals owing to their lack of inversion symmetry, Cd3As2 is known as a Dirac semimetal owing to its linear band crossing at the Fermi level, and WTe2 is termed a resonant compensated semimetal owing to its perfect electron-hole symmetry. Here we introduce LaSb, a simple rock-salt structure material that lacks broken inversion symmetry, perfect linear band crossing, and perfect electron-hole symmetry yet exhibits all the exotic field-induced behaviours of these more complex semimetals. It shows a field-induced universal TI resistivity with a plateau at roughly 15 K, ultrahigh mobility of carriers in the plateau region, quantum oscillations with the angle dependence of a two-dimensional Fermi surface, and XMR of about one million percent at 9 T. Owing to its structural simplicity, LaSb represents an ideal model system to formulate a theoretical understanding of the exotic consequences of breaking time reversal symmetry in topological semimetals.

  14. Holocene aeolian sediments on the NE Tibetan Plateau

    Science.gov (United States)

    Stauch, G.; Lehmkuhl, F.; Hilgers, A.; Zhao, H.

    2012-04-01

    The semiarid climate of the northeastern Tibetan Plateau supports the formation of different types of aeolian sediments and landforms during the Holocene. Aeolians silts and sands in the catchment of the Donggi Cona in an elevation above 4000m to 4800 m asl reflect variable climate conditions during that time as well as different sediment sources. Based on 51 OSL datings and catchment wide geomorphological mapping a complex pattern of long and short distance sediment transport has been reconstructed. Only few aeolian archives are preserved from the late Pleistocene in this mountain environment indicating cold and dry climate conditions which prevented a continuous accumulation. During the early Holocene a phase of increased aeolian sedimentation of sand at the slopes of the mountains has been reconstructed. The sand originated from a large alluvial fan which was highly active during the Pleistocene. In addition, a thin loess cover is preserved at a few sites in the neighboring mountains ranges. The sedimentation of the loess started around 2000 years later than the sedimentation of the sand at the foot slope. Both archives are related to an increase in precipitation at the northern margin of the Tibetan Plateau which was related to a strengthening of the Asian Monsoon during that time. The wetter climate conditions favored the development of a vegetation cover which leads to the trapping and fixation of the aeolian sediments. However, with a further strengthening of the Monsoon systems these archives subsequently eroded due to higher run off and accumulated as colluvial and fluvial deposits in the basins. These phase lasted until 6 ka. A second aeolian period started at around 3 ka with the formation new dunes in the basins. This period can be associated with dry and cold climate of the late Holocene supporting the reactivation of the sand in the area. This might be further enhanced by an increased human impact by grazing during the late Holocene and resulting

  15. Geodynamical basis for crustal deformation under the Tibetan Plateau

    Science.gov (United States)

    Liu, H.-S.

    1985-01-01

    Plate tectonics and satellite-derived gravity data are used to examine crustal deformation under the Tibetan Plateau. A spherical harmonic analysis is given for the global plate boundary system, and the crustal stresses in Tibet are calculated from satellite gravity data. A superimposed stress system is constructed. The stress patterns reveal that the cold downwelling mantle convection flow beneath southern Tibet pulls the Indian plate down but applies a bending moment on the end of the plate to uplift and support the mass of the Himalayas.

  16. An outcome of surgical management of the tibial plateau fractures

    Directory of Open Access Journals (Sweden)

    Biju Ravindran

    2014-01-01

    Full Text Available Background: Advance in mechanization and acceleration of travel has been accompanied by an increase in number and severity of fractures and those of the tibial plateau are not an exception. As it is one of the major weight bearing joints of the body, fractures around it will be of at most importance. Aims: (1 To restore articular congruity and limb alignment by open reduction and rigid internal fixation. (2 To enable early knee motion and improve quadriceps and hamstring power. (3 To study the role of surgical treatment and functional outcome in tibial plateau fractures and its complications. Settings and Design: A prospective study was carried out, 32 cases of the tibial plateau fractures, which were admitted from August 2010 to April 2012 at Department of Orthopedics of our Hospital. Materials and Methods: 32 patients underwent surgical treatment for tibial plateau fractures. Fractures were classified according to the Schatzker′s system. The indications for surgery were defined as the presence of displacement, depression and instability being more than 4 mm, 10 mm and 10 degrees. The mean follow-up was 12 months. The selected patients were evaluated and were taken up for surgery. The indicated fractures were treated with closed reduction and internal fixation with percutaneous cannulated cancellous screws, external fixator, open reduction and internal fixation with buttress plate with or without bone grafting. The range of motion was started soon after surgery. The patients were advised nonweight bearing up to 6-8 weeks. Total weight bearing deferred until 12 weeks or complete union of fracture. Statistical Analysis: All parameters before and after the treatment were expressed in mean ± standard deviation and analyzed by the Student′s t-test using SPSS version 16. Results: The knee range of motion was excellent to very good and weight bearing after complete union was satisfactory. Malunion in two cases, knee stiffness in three

  17. Soil carbon sequestration potential for "grain for green" project in Loess Plateau, China

    Science.gov (United States)

    Chang, R.; Fu, B.; Liu, Gaisheng; Liu, S.

    2011-01-01

    Conversion of cropland into perennial vegetation land can increase soil organic carbon (SOC) accumulation, which might be an important mitigation measure to sequester carbon dioxide from the atmosphere. The "Grain for Green" project, one of the most ambitious ecological programmes launched in modern China, aims at transforming the low-yield slope cropland into grassland and woodland. The Loess Plateau in China is the most important target of this project due to its serious soil erosion. The objectives of this study are to answer three questions: (1) what is the rate of the SOC accumulation for this "Grain for Green" project in Loess Plateau? (2) Is there a difference in SOC sequestration among different restoration types, including grassland, shrub and forest? (3) Is the effect of restoration types on SOC accumulation different among northern, middle and southern regions of the Loess Plateau? Based on analysis of the data collected from the literature conducted in the Loess Plateau, we found that SOC increased at a rate of 0.712 TgC/year in the top 20 cm soil layer for 60 years under this project across the entire Loess Plateau. This was a relatively reliable estimation based on current data, although there were some uncertainties. Compared to grassland, forest had a significantly greater effect on SOC accumulation in middle and southern Loess Plateau but had a weaker effect in the northern Loess Plateau. There were no differences found in SOC sequestration between shrub and grassland across the entire Loess Plateau. Grassland had a stronger effect on SOC sequestration in the northern Loess Plateau than in the middle and southern regions. In contrast, forest could increase more SOC in the middle and southern Loess Plateau than in the northern Loess Plateau, whereas shrub had a similar effect on SOC sequestration across the Loess Plateau. Our results suggest that the "Grain for Green" project can significantly increase the SOC storage in Loess Plateau, and it is

  18. Soil carbon sequestration potential for "Grain for Green" project in Loess Plateau, China.

    Science.gov (United States)

    Chang, Ruiying; Fu, Bojie; Liu, Guohua; Liu, Shuguang

    2011-12-01

    Conversion of cropland into perennial vegetation land can increase soil organic carbon (SOC) accumulation, which might be an important mitigation measure to sequester carbon dioxide from the atmosphere. The "Grain for Green" project, one of the most ambitious ecological programmes launched in modern China, aims at transforming the low-yield slope cropland into grassland and woodland. The Loess Plateau in China is the most important target of this project due to its serious soil erosion. The objectives of this study are to answer three questions: (1) what is the rate of the SOC accumulation for this "Grain for Green" project in Loess Plateau? (2) Is there a difference in SOC sequestration among different restoration types, including grassland, shrub and forest? (3) Is the effect of restoration types on SOC accumulation different among northern, middle and southern regions of the Loess Plateau? Based on analysis of the data collected from the literature conducted in the Loess Plateau, we found that SOC increased at a rate of 0.712 TgC/year in the top 20 cm soil layer for 60 years under this project across the entire Loess Plateau. This was a relatively reliable estimation based on current data, although there were some uncertainties. Compared to grassland, forest had a significantly greater effect on SOC accumulation in middle and southern Loess Plateau but had a weaker effect in the northern Loess Plateau. There were no differences found in SOC sequestration between shrub and grassland across the entire Loess Plateau. Grassland had a stronger effect on SOC sequestration in the northern Loess Plateau than in the middle and southern regions. In contrast, forest could increase more SOC in the middle and southern Loess Plateau than in the northern Loess Plateau, whereas shrub had a similar effect on SOC sequestration across the Loess Plateau. Our results suggest that the "Grain for Green" project can significantly increase the SOC storage in Loess Plateau, and it is

  19. Lake overspill and onset of fluvial incision in the Iranian Plateau: Insights from the Mianeh Basin

    Science.gov (United States)

    Heidarzadeh, Ghasem; Ballato, Paolo; Hassanzadeh, Jamshid; Ghassemi, Mohammad R.; Strecker, Manfred R.

    2017-07-01

    Orogenic plateaus represent a prime example of the interplay between surface processes, climate, and tectonics. This kind of an interplay is thought to be responsible for the formation, preservation, and, ultimately, the destruction of a typical elevated, low-internal relief plateau landscape. Here, we document the timing of intermontane basin filling associated with the formation of a low-relief plateau morphology, followed by basin opening and plateau-flank incision in the northwestern Iranian Plateau of the Arabia-Eurasia collision zone. Our new U-Pb zircon ages from intercalated volcanic ashes in exposed plateau basin-fill sediments from the most external plateau basin (Mianeh Basin) document that the basin was internally drained at least between ∼7 and 4 Ma, and that from ∼5 to 4 Ma it was characterized by an ∼2-km-high and ∼0.5-km-deep lake (Mianeh paleolake), most likely as a result of wetter climatic conditions. At the same time, the eastern margin of the Mianeh Basin (and, therefore, of the Iranian Plateau) experienced limited tectonic activity, as documented by onlapping sediments and smoothed topography. The combination of high lake level and subdued topography at the plateau margin led to lake overspill, which resulted in the cutting of an ∼1-km-deep bedrock gorge (Amardos) by the Qezel-Owzan River (QOR) beginning at ∼4 Ma. This was associated with the incision of the plateau landscape and the establishment of fluvial connectivity with the Caspian Sea. Overall, our study emphasizes the interplay between surface and tectonic processes in forming, maintaining, and destroying orogenic plateau morphology, the transitional nature of orogenic plateau landscapes on timescales of 106 yr, and, finally, the role played by overspilling in integrating endorheic basins.

  20. [Assessment indicators of soil quality in hilly Loess plateau].

    Science.gov (United States)

    Xu, Mingxiang; Liu, Guobin; Zhao, Yunge

    2005-10-01

    By the methods of sensitivity analysis, main component analsis and discriminant analysis, this paper screened the sensitive indicators from 32 soil attributes to assess the productivity and erosion-resistance ability of the soils in hilly Loess Plateau. The results showed that soil available phosphorus content, anti-scouring ability, infiltration coefficient, labile organic carbon content, organic matter content and urease activity were the most sensitive indicators for soil quality assessment and the main targets for soil quality management and improvement, while soil biological indicators were with high and medium sensitivity. Five soil quality factors were summed up from 29 soil chemical, physical and biological attributes, i. e., organic matter, texture, phosphorus, porosity and microstructure. Except the factor porosity, the other four factors were significantly different between different land use types. Eight indicators including soil organic matter content, infiltration coefficient, anti-scouring ability, CEC, invertase activity, mean weight diameter (MWD) of aggregates, available phosphorus, and MWD of microaggregate were identified as the assessment indicators of the soil quality in hilly Loess Plateau, with the organic matter content, infiltration coefficient and anti-scouring ability as the key indicators.

  1. Unilatelaral iris plateau syndrome after the use of ecstasy

    Directory of Open Access Journals (Sweden)

    Jovanović Predrag

    2009-01-01

    Full Text Available Bacground. Courmon street name for 3,4-Methylenedioxymethamphetamine (MDMA is ecstasy. This widely abused 'recreational' drug causes both an increased release of monoamine neurotransmitters, including serotonine and dopamine, and an increased reuptake inhibition of serotonin. As a consequence, mydriasis and increased intraocular pressure (IOP in predisposed patients occur. We present herein a rare case of acute increased IOP after use of ecstasy. Case report. A female patient, aged 38 years, visited doctor complaing of a decreased vision acuity and severe pain in the left eye and in the left part of the head. The initial treatment was urgent antiglaucomatous therapy followed by withdrawal of subjective problems of the patient and improvement of objective finding. History taking procedure reveled that just before the onset of the pain the patient had used ecstasy and had had similar 'experience' 6 years ago after cocaine snorting. She had not been to a doctor although she had experienced sporadic migrenous pain. Previous medical records excavation of revealed optic disk (cup-to-dise C/D=06, Bjerum arcuate scotoma and iris plateau with narrow chamber angle (Scheie II- III so the diagnosis was a rare unilateral iris plateau syndrome of the left eye. Although the patient was given some pieces of information about the dangerous and possible deadly consequences of psychoactive substance abuse, she has not continue the treatment. Conclusion. Ecstasy abuse might cause a complete loss of vision, thus medicametous and surgical treatment are obligatory.

  2. Climatic variability of the column ozone over the Iranian plateau

    Science.gov (United States)

    Mousavi, Seyyed Shafi; Farajzadeh, Manuchehr; Rahimi, Yousef Ghavidel; Bidokhti, Abbasali Aliakbari

    2017-06-01

    This study analyzes the total ozone column (TOC) variability over the Iranian plateau (Esfahan) from 1978 to 2011. Results show that the annual average of TOC in Esfahan tends to decrease with time, which is strongly dependent on the season, with maximum values during the winter-spring months (more than 2.2 %/decade). By applying a defined threshold that includes the TOC monthly -2 σ, it is found that the maximum occurrence of low ozone events (LOEs) tends to be more frequent in the second half of year with about four-fifth of the observed LOEs (last summer, autumn, and early winter). During two cases of LOE, the tropopause height (TH) was uplifted 2-4 km with temperature of 10 °C colder than the long-term mean, and the synoptic pattern was characterized by high-pressure systems in UTLS region. The extreme LOEs were consistent with the horizontal transport of ozone-poor air toward the Iranian plateau and vertical advection in UTLS region. The former mechanism plays a primary role in formation of extreme LOEs based on the observed TOC reductions during previous days over the source regions (Sahara desert and Himalaya region). Day-to-day variations of maximum UV index during LOEs show that by a decrease in TOC 14 %, while the aerosol optical depth (AOD) in the cloudless condition reach their lowest rates (lower than 0.3), UV radiation exceeds very high and extreme levels in late winter and mid-spring, respectively.

  3. Snow surface microbiome on the High Antarctic Plateau (DOME C.

    Directory of Open Access Journals (Sweden)

    Luigi Michaud

    Full Text Available The cryosphere is an integral part of the global climate system and one of the major habitable ecosystems of Earth's biosphere. These permanently frozen environments harbor diverse, viable and metabolically active microbial populations that represent almost all the major phylogenetic groups. In this study, we investigated the microbial diversity in the surface snow surrounding the Concordia Research Station on the High Antarctic Plateau through a polyphasic approach, including direct prokaryotic quantification by flow cytometry and catalyzed reporter deposition fluorescence in situ hybridization (CARD-FISH, and phylogenetic identification by 16S RNA gene clone library sequencing and 454 16S amplicon pyrosequencing. Although the microbial abundance was low (<10(3 cells/ml of snowmelt, concordant results were obtained with the different techniques. The microbial community was mainly composed of members of the Alpha-proteobacteria class (e.g. Kiloniellaceae and Rhodobacteraceae, which is one of the most well-represented bacterial groups in marine habitats, Bacteroidetes (e.g. Cryomorphaceae and Flavobacteriaceae and Cyanobacteria. Based on our results, polar microorganisms could not only be considered as deposited airborne particles, but as an active component of the snowpack ecology of the High Antarctic Plateau.

  4. Crustal kinematics of the Colorado Plateau from GPS geodesy

    Science.gov (United States)

    Holland, A. A.; Broermann, J.; Bennett, R. A.; Kreemer, C.; Blewitt, G.

    2013-12-01

    We present results from new continuous and campaign GPS networks spanning the state of Arizona and the southern portion of Utah. The 33 station continuous GPS network, funded by the NSF EarthScope Program, supplements a sparse distribution of continuous GPS stations that comprise the NSF EarthScope Plate Boundary Observatory network. The campaign network originally established by the National Geodetic survey in the mid-1990's, has been reoccupied two or more times over the past five years with support from the Arizona Geological Survey. The data from the continuous GPS stations are analyzed independently with the GIPSY and GAMIT software. The new horizontal velocity data set provides an improved image of deformation in the transition zone between the Colorado Plateau and the Northern and Southern Basin and Ranges Provinces. Preliminary modeling of the crustal kinematics reveals that only a very limited part of the region can be modeled as a rigid-body rotation. Most of the area is part of a broad zone of diffuse east-west directed extension from the Rio Grande Rift in the East to the Mojave Desert in the west. Only near the transition from the northern Colorado Plateau to the northern Basin and Range Province is the extension more localized. Besides a discussion of the regional kinematics, we will also discuss the affect the 2010 El Mayor-Cucapah earthquake had on the geodetic data in the southern Basin and Range.

  5. Climatic variability of the column ozone over the Iranian plateau

    Science.gov (United States)

    Mousavi, Seyyed Shafi; Farajzadeh, Manuchehr; Rahimi, Yousef Ghavidel; Bidokhti, Abbasali Aliakbari

    2016-08-01

    This study analyzes the total ozone column (TOC) variability over the Iranian plateau (Esfahan) from 1978 to 2011. Results show that the annual average of TOC in Esfahan tends to decrease with time, which is strongly dependent on the season, with maximum values during the winter-spring months (more than 2.2 %/decade). By applying a defined threshold that includes the TOC monthly -2σ, it is found that the maximum occurrence of low ozone events (LOEs) tends to be more frequent in the second half of year with about four-fifth of the observed LOEs (last summer, autumn, and early winter). During two cases of LOE, the tropopause height (TH) was uplifted ~2-4 km with temperature of 10 °C colder than the long-term mean, and the synoptic pattern was characterized by high-pressure systems in UTLS region. The extreme LOEs were consistent with the horizontal transport of ozone-poor air toward the Iranian plateau and vertical advection in UTLS region. The former mechanism plays a primary role in formation of extreme LOEs based on the observed TOC reductions during previous days over the source regions (Sahara desert and Himalaya region). Day-to-day variations of maximum UV index during LOEs show that by a decrease in TOC ~14 %, while the aerosol optical depth (AOD) in the cloudless condition reach their lowest rates (lower than 0.3), UV radiation exceeds very high and extreme levels in late winter and mid-spring, respectively.

  6. Plateau 'pop-up' in the great 1897 Assam earthquake.

    Science.gov (United States)

    Bilham, R; England, P

    2001-04-12

    The great Assam earthquake of 12 June 1897 reduced to rubble all masonry buildings within a region of northeastern India roughly the size of England, and was felt over an area exceeding that of the great 1755 Lisbon earthquake. Hitherto it was believed that rupture occurred on a north-dipping Himalayan thrust fault propagating south of Bhutan. But here we show that the northern edge of the Shillong plateau rose violently by at least 11 m during the Assam earthquake, and that this was due to the rupture of a buried reverse fault approximately 110 km in length and dipping steeply away from the Himalaya. The stress drop implied by the rupture geometry and the prodigious fault slip of 18 +/- 7 m explains epicentral accelerations observed to exceed 1g vertically and surface velocities exceeding 3 m s-1 (ref. 1). This quantitative observation of active deformation of a 'pop-up' structure confirms that faults bounding such structures can penetrate the whole crust. Plateau uplift in the past 2-5 million years has caused the Indian plate to contract locally by 4 +/- 2 mm yr-1, reducing seismic risk in Bhutan but increasing the risk in northern Bangladesh.

  7. Hydrodynamical models of Type II-Plateau Supernovae

    CERN Document Server

    Bersten, Melina C; Hamuy, Mario

    2011-01-01

    We present bolometric light curves of Type II-plateau supernovae (SNe II-P) obtained using a newly developed, one-dimensional Lagrangian hydrodynamic code with flux-limited radiation diffusion. Using our code we calculate the bolometric light curve and photospheric velocities of SN1999em obtaining a remarkably good agreement with observations despite the simplifications used in our calculation. The physical parameters used in our calculation are E=1.25 foe, M= 19 M_\\odot, R= 800 R_\\odot and M_{Ni}=0.056 M_\\odot. We find that an extensive mixing of 56Ni is needed in order to reproduce a plateau as flat as that shown by the observations. We also study the possibility to fit the observations with lower values of the initial mass consistently with upper limits that have been inferred from pre-supernova imaging of SN1999em in connection with stellar evolution models. We cannot find a set of physical parameters that reproduce well the observations for models with pre-supernova mass of \\leq 12 M_\\odot, although mode...

  8. Radiographic predictors of compartment syndrome in tibial plateau fractures.

    Science.gov (United States)

    Ziran, Bruce H; Becher, Stephen John

    2013-11-01

    The purpose of this article was to evaluate the relationship of radiographic features of tibial plateau fractures to the development of compartment syndrome. We hypothesized that the direction and degree of initial displacement of the femur on the tibia, and the amount of tibial widening (TW), were correlated with the development of compartment syndrome. Retrospective case-control study. Single level 1 trauma center. Retrospective evaluation of 158 patients with 162 plateau fractures. Grouping with and without compartment syndrome. The following data were obtained: age, sex, Schatzker and OTA/AO classification, open/closed status, TW, and femoral displacement (FD). A univariate statistical and a logistical regression analysis were performed to determine significance. The overall rate of compartment syndrome was 11%. Univariate analysis found both the TW and FD to be significant with respect to development of compartment syndrome (P compartment syndrome. Logistic regression found FD and Schatzker grade to be significant. Our study is the first to identify easily obtained radiographic parameters that correlate to the occurrence compartment syndrome. There may also be a relationship between TW and FD, as noted by regression result. This study helps to assess which patients with a fracture are at higher risk for developing a compartment syndrome. Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

  9. Satellite Observed Environmental Changes over the Qinghai-Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Kuo-Hsin Tseng

    2011-01-01

    Full Text Available We use satellite observed and model atmospheric variables, including land surface temperature, snowfall, snow extent, precipitation, and water vapor contents to study the feasibility of quantifying anthropogenic climate change over high elevation areas such as the Qinghai-Tibetan Plateau. Five types of satellite data and outputs from Atmospheric General Circulation Model (AGCMs are used to study these climate change indicators: (1 AIRS/AMSU/HSB atmospheric sounding system onboard the Aqua platform, 2003 ~ 2009, (2 Moderate Resolution Imaging Spectroradiometer (MODIS onboard Terra, 2001 ~ 2009, (3 The Tropical Rainfall Measuring Mission (TRMM precipitation measurements, 1999 ~ 2009, (4 the ERA-interim (ECMWF Interim Reanalysis, 1989 ~ 2009, and (5 the Japanese 25-year Reanalysis Project (JRA-25 AGCM data, 1979 ~ 2009. We find that biases exist between temperature observations and model data 0.29 ~ _ AIRS and JRA-25, respectively. The trends for each of the atmospheric variables at best have a qualitative agreement, presumably because the data spans of satellite observations are too short (7 ~ 10 years. The temperature trends for 4000 ~ 5000 m over the Plateau are estimated to be 0.01 ~ _ yr-1, qualitatively agreeing with the published rate of _ decade-1 over the last three decades using in situ data.

  10. Old-field plant succession on the Pajarito Plateau

    Energy Technology Data Exchange (ETDEWEB)

    Foxx, T.; Mullen, M.; Salisbury, M. [Los Alamos National Lab., NM (United States); Tierney, G. [Tierney (Gail), Santa Fe, NM (United States)

    1997-10-01

    Eight fallow historic fields of the ponderosa pine and pinon-juniper cover types were surveyed to determine species composition and distribution. The purpose of the study was to understand plant succession on old fields as related to mechanically manipulated sites such as material disposal areas (MDAs). Additionally, the authors wanted a listing of species on disturbed lands of the Pajarito Plateau to aide in the reclamation planning of MDAs using native species. They also wanted to determine if any species could be used as an indicator of disturbance. The eight historic fields were all within Los Alamos County, New Mexico, and had been abandoned in 1943. Two sites were within the boundaries of Los Alamos National Laboratory and were studied both in 1982 and 1993. The study provides a description of each of the field sites, historic information about the homesteads from patent applications, a photographic record of some of the sites, and a listing of species found within each field. The study showed that there were 78 different plant species found on disturbed sites. Of these 78 species, 23 were found to be dominant on one or more of the MDAs or old fields. Although, the disturbance history of each site is imperfectly known, the study does provide an indication of successional processes within disturbed sites of the Pajarito Plateau. Additionally, it provides a listing of species that will invade disturbed sites, species that may be used in site reclamation.

  11. Stick-slip advance of the Kohat Plateau in Pakistan

    Science.gov (United States)

    Satyabala, S. P.; Yang, Zhaohui; Bilham, Roger

    2012-02-01

    Throughout most of the Himalaya, slip of the Indian Plate is restrained by friction on the interface between the plate and the overlying wedge of Himalayan rocks. Every few hundred years, this interface--or décollement--ruptures in one or more Mw >=8 earthquakes. In contrast, in the westernmost Himalaya, the Indian Plate slips aseismically beneath wide plateaux fronting the Kohistan Mountains. The plateaux are underlain by viscous décollements that are unable to sustain large earthquakes. Potwar, the widest of these plateaux is underlain by viscous salt, which currently permits it to slide at rates of about 3mmyr-1 (refs , ), much slower than its 2 Myr average. This deceleration has been attributed to recently increased friction through the loss of salt from its décollement. Here we use interferometric synthetic aperture radar and seismic data to assess movement of the Kohat Plateau--the narrowest and thickest plateau. We find that in 1992 an 80 km2 patch of the décollement ruptured in a rare Mw 6.0 earthquake, suggesting that parts of the décollement are locally grounded. We conclude that this hybrid seismic and aseismic behaviour represents an evolution of the mode of slip of the plateaux from steady creep towards increasingly widespread seismic rupture.

  12. Morphology observation of new Echinococcus shiquicus in southern Qinghai plateau%青海省青南高原棘球绦虫新种-石渠棘球绦虫的形态学观察

    Institute of Scientific and Technical Information of China (English)

    曾诚

    2013-01-01

    OBJECTIVE To observe pathogen morphology of new type of Echinococcus shiquicus attested by cytb gene analysis in southern Qinghai plateau, then analyze pathogen morphology characteristics comparing with other Echinococcus. METHODS Collected Echinococcus shiquicus from Vulpes ferrilata intestine, then observed its morphology characteristics after carmine staining. Echinococcus shiquicus from Ochotona curzoniae was conducted on pathological characteristics detection after PAS staining with paraffin-embedded sections. Cytb gene-sequence was analyzed in adult and pathological tissues. RESULTS Body of adult Echinococcus shiquicus which was founded in southern Qinghai plateau was short about 1.2 -1.8mm, typical developments of adult Echinococcus shiquicus were comprised of scolex, mature proglottid and gravid proglottid.There was a small number of proglottid. Rostellum hook easily dropped off, the length of large hoop was 20.0-24.0μm, the length of small hoop was 16.0-18.0μm; body size of adult Echinococcus shiquicus was the smallest in all Echinococcus known now, head hoop number about 18-36; location of gonopore was very special, opened at mature proglottid body side about 1/3-1/4, the number of eggs in uterine of gravid proglottid was small, no-branch gravid proglottid uterine, liking bag. Characteristics pathological change under microscope: single atrial type, diameter about 10mm. There was brood pouch, which adhere to germinal layer and with lots of protoscolex; no ascus, stratum corneum was rather thick. Main pathological change was chronic proliferative inflammation. CONCLUSION As a new type Echinococcus which found in wild animal in southern Qinghai plateau, Echinococcus shiquicus enlarges research scope on Echinococcus pathogen. There are three kinds of Echinococcus in southern Qinghai plateau, such as Echinococcus shiquicus, E granulosus and E.multiocularis. By morphology observation of Echinococcus shiquicus in southern Qinghai plateau, it provides basic

  13. Determining geometric links between glaciers and lakes on the Tibetan plateau

    NARCIS (Netherlands)

    Phan Hien, V.; Lindenbergh, R.C.; Menenti, M.

    2013-01-01

    The Tibetan plateau and surrounding mountain ranges contain the largest amount of ice outside the polar region. The Tibetan plateau also contains more than one thousand lakes and is the origin of a large part of the water resources of South and East Asia, the most densely populated regions on earth.

  14. Pollen-based reconstructions of Holocene vegetation and climatic change of Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    唐领余; 李春海; 于革; 沈才明

    2003-01-01

    A synthesis of Holocene pollen records from the Tibetan Plateau shows the history of vegetation and climatic changes during the Holocene. Palynological evidences from 24 cores/sections have been compiled and show that the vegetation shifted from subalpine/alpine conifer forest to subalpine/alpine evergreen sclerophyllous forest in the southeastern part of the plateau; from alpine steppe to alpine desert in the central, western and northern part; and from alpine meadow to alpine steppe in the eastern and southern plateau regions during the Holocene. These records show that increases in precipitation began about 9 ka from the southeast, and a wide ranging level of increased humidity developed over the entire of the plateau around 8-7 ka, followed by aridity from 6 ka and a continuous drying over the plateau after 4-3 ka. The changes in Holocene climates of the plateau can be interpreted qualitatively as a response to orbital forcing and its secondary effects on the Indian Monsoon which expanded northwards during the early Holocene and retreated from the plateau since the midHolocene. Also, there is teleconnection between the Tibetan Plateau and North Atlantic.

  15. Rising process of the Qinghai-Xizang (Tibet) Plateau and its mechanism

    Institute of Scientific and Technical Information of China (English)

    钟大赉; 丁林

    1996-01-01

    The rising of the Qinghai-Xizang Plateau has character of multistage (45-38 Ma, 25-17 Ma, 13-8 Ma, 3 Ma-present), inhomogeneity and hetero-speed. The whole uprising of the plateau and local rapid rising in its periphery since Late Pliocene is a synthetical result of at least two or more mechanisms.

  16. Environmental significance of mineral weathering and pedogenesis of loess on the southernmost Loess Plateau, China

    NARCIS (Netherlands)

    Huang, C.; Zhao, W.; Liu, F.; Tan, W.F.; Koopal, L.K.

    2011-01-01

    Soils derived from the Loess Plateau of China are regionally important and expression of the soil properties along the soil profile may be directly related to climate changes. The objective of this research was to analyze the clay mineral transformation of loess from the southernmost Loess Plateau,

  17. Imprint of a dissolved cobalt basaltic source on the Kerguelen Plateau

    NARCIS (Netherlands)

    Bown, J.; Boye, M.; Laan, P.; Bowie, A.R.; Park, Y.H.; Jeandel, C.; Nelson, D.M.

    2012-01-01

    Processes of cobalt (Co) entrainment from shelf sediments over the Kerguelen Plateau were studied during the KEOPS (Kerguelen Ocean Plateau compared Study) in order to explain the exceptionally high dissolved cobalt concentrations that have been measured in the surface waters above the Kerguelen Pla

  18. Plateau of α-function and c-minimal homoclinic orbits

    Institute of Scientific and Technical Information of China (English)

    LI Xia; CUI Xiaojun

    2006-01-01

    We consider the construction of the plateau of the α-function in a hyperbolic and positive definite Lagrangian system, and link the boundries of the α-function's plateau with the distribution of c-minimal homoclinic orbits to Aubry sets.

  19. Arthroscopically assisted osteosynthesis of tibial plateau fractures in patients older than 55 years

    NARCIS (Netherlands)

    Roerdink, WH; Oskam, J; Vierhout, PAM

    2001-01-01

    Purpose: To evaluate the end results of arthroscopically assisted osteosynthesis of tibial plateau fractures in patients older than 55 years of age. Type of Study: Case series. Methods: Over a 5-year period, 201 consecutive patients presented with tibial plateau fracture; 131 of these patients were

  20. A wavelet analysis of the relationship between Loess Plateau erosion and sunspots

    NARCIS (Netherlands)

    Gao, P.; Geissen, V.; Temme, A.J.A.M.; Ritsema, C.J.; Mu, X.; Wang, F.

    2014-01-01

    The Chinese Loess Plateau is one of the most rapidly eroding regions in the world. The purpose of this study is to find out to which extent soil erosion on the Loess Plateau is driven by sunspot activity. We analyzed the relation between annual sediment discharge (from 1919 to 2010) from the Loess P

  1. Mapping the plateau of novices in virtual reality simulation training of mastoidectomy

    DEFF Research Database (Denmark)

    A.W. Andersen, Steven; Konge, Lars; Mikkelsen, Peter Trier

    2016-01-01

    To explore why novices' performance plateau in directed, self-regulated virtual reality (VR) simulation training and how performance can be improved.......To explore why novices' performance plateau in directed, self-regulated virtual reality (VR) simulation training and how performance can be improved....

  2. Constraining properties of GRB magnetar central engines using the observed plateau luminosity and duration correlation

    NARCIS (Netherlands)

    A. Rowlinson; B.P. Gompertz; M. Dainotti; R.A.M.J. Wijers; A.J. van der Horst

    2014-01-01

    An intrinsic correlation has been identified between the luminosity and duration of plateaus in the X-ray afterglows of gamma-ray bursts (GRBs; Dainotti et al. 2008), suggesting a central engine origin. The magnetar central engine model predicts an observable plateau phase, with plateau durations an

  3. Facilitation of plateau potentials in turtle motoneurones by a pathway dependent on calcium and calmodulin

    DEFF Research Database (Denmark)

    Perrier, J F; Mejia-Gervacio, S; Hounsgaard, J

    2000-01-01

    or trifluoperazine reduced the amplitude of depolarization-induced plateau potentials. Inactivation of calmodulin also inhibited facilitation of plateau potentials by activation of group I metabotropic glutamate receptors or muscarinic receptors. 3. In low-sodium medium and in the presence of tetraethylammonium...

  4. The role of the Hikurangi Plateau in the dynamics of the Hikurangi Subduction Margin

    Science.gov (United States)

    Willis, David; Moresi, Louis; Betts, Peter; Ailleres, Laurent

    2015-04-01

    The collision of the Hikurangi Plateau with the Hikurangi Subduction Zone coincides with a change from extension to shortening in the overriding Australian Plate. The 15km thick oceanic Hikurangi Plateau is juxtaposed with Chatham Rise at the southern edge of the subduction margin, possibly extending an unknown distance beneath the Chatham Rise. We explore the influence of the Hikurangi Plateau and its size on subduction dynamics using a series of 3D visco-elastic Underworld models with free slip boundary conditions. The models rely on negative slab buoyancy to drive subduction, with the buoyant oceanic plateau altering the dynamics. The models are benchmarked against New Zealand GPS velocities, paleomagnetic rotations, and fault zones. Both the overriding and subducting plates have undergone significant rotation since 23Ma with ~90° clockwise rotation of the overriding plate relative to the subducting plate. Distinctive fault zones have also been created with the Marlborough Fault Zone facilitating escape tectonics around the Chatham Rise; the North Island Dextral Fault Belt allowing lateral movement between the fore and back-arcs; extension in Taupo Volcanic Zone assisting back-arc extension; and active N-S extension in the Chatham Rise adjacent to the Hikurangi Plateau. In a model without an oceanic plateau, the subduction zone undergoes roll-back along its entire margin. Extension occurs along the overriding plate adjacent to subduction, with shortening limited to the collision of the Chatham Rise. Rotation rates adjacent to the Chatham Rise are extremely high, and decrease rapidly northward and there is no rotation of the subducting plate. When an oceanic plateau is included in the model, shortening occurs at the southern margin of the subduction zone as subduction shallows with the entry of the bouyant plateau. Rotation starts in the subducting plate as the plateau enters the subduction zone. This rotation is attributed to a decrease in slab pull southward

  5. Sandy Desertification Status and its Driving Mechanism in North Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    DONG Yuxiang

    2004-01-01

    As the main body of Qinghai-Tibetan Plateau, North Tibet Plateau is one of three major sandy desertification regions in China and also a representative sandy desertification zone of Qinghai-Tibet Plateau. Accordingly, it is an important region for the study of recent sandy desertification processes and formation mechanism. From such aspects as desertified land types, areas and distributions etc., this paper analyses in detail the sandy desertification status on North Tibet Plateau,and qualitatively and quantitatively deals with the main factors that affect recent sandy desertification processes and the driving mechanism. Research results show that North Tibet Plateau is an important sandy desertification region in China characterized with large desertified land areas, diversified types,high severity, extensive distributions and serious damages. Sandy desertification occurrence and development resulted from combined effects of natural factors, anthropogenic factors, natural processes and man-made processes, of which climatic change is the main driving force.

  6. Kasulik on puhata pikas kuus / Mati Feldmann

    Index Scriptorium Estoniae

    Feldmann, Mati, 1961-

    2005-01-01

    Äripäeva arvamustoimeteja selgitab, miks fikseeritud kuupalga juures on kasulikum puhata kalendrikuus, milles on rohkem kalendripäevi ja analüüsib, milline suvekuu on puhkuseks rahaliselt soodsaim

  7. High prevalence of false-positive plateau phenomena during VO2max testing in adolescents.

    Science.gov (United States)

    Beltrami, Fernando G; Wong, Del P; Noakes, Timothy D

    2014-09-01

    It is believed that a plateau in oxygen consumption (VO2) at the end of an incremental exercise test identifies the upper limits of cardiovascular capacity. We investigated how different criteria influence the frequency with which the "plateau phenomenon" is detected and the prevalence at which "false" plateau phenomena occurs during sub-maximal exercise. Cross-sectional. Six different criteria with 3 different sampling intervals each were used to identify the "plateau phenomenon" from a single data set comprising 63 incremental exercise tests along with secondary criteria based on target heart rate (HR) and respiratory exchange ratio (RER). A single criterion from the original 18 (HALF) was also used to detect the incidence of any plateau phenomena during each test. The plateau phenomenon was detected in 16-82% of the tests depending on the criteria used, mostly as a result of the different sampling intervals. HALF identified 103 "plateau phenomena" but 73 (70.9%) of these occurred during sub-maximal exercise and so were "false". "False" plateaus were verified by at least one secondary criterion in 27% of cases. Participants reached the HR and RER targets after 83.6 ± 11.7% and 81.9 ± 18.1% of total test duration, respectively. The wide range in the percentage of plateau phenomena detected by different criteria plus the high rate (71%) of "false" plateau during sub-maximal exercise could indicate that this phenomenon is a calculation artifact rather than an indicator of true physiological events. Secondary criteria can be reached early in exercise and often identify "false" plateau phenomena as "true". Copyright © 2013 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  8. The Dynamic Plateau Monsoon Index and Its Association with General Circulation Anomalies

    Institute of Scientific and Technical Information of China (English)

    XUN Xueyi; HU Zeyong; MA Yaoming

    2012-01-01

    Based on monthly ECMWF reanalysis-Interim (ERA-Interim) reanalysis data,along with monthly precipitation and temperature data,the Dynamic Plateau Monsoon Index (DPMI) is defined.The results of a contrast analysis of the DPMI versus the Traditional Plateau Monsoon Index (TPMI) are described.The response of general circulation to northern Qinghai-Xizang Plateau summer monsoon anomalies and the correlation of the DPMI with general circulation anomalies are investigated.The results show that,the DPMI reflected meteorological elements better and depicted climate variation more accurately than the TPMI.In years when the plateau summer monsoon is strong,the low over the plateau and the trough near the eastern coast of Asia are deeper and higher than normal over South China.This correlation corresponds to two anomalous cyclones over the plateau and the eastern coast of Asia and an anomalous anticyclone in South China.The plateau and its adjacent regions are affected by anomalous southwesterly winds that transport more moisture to South China and cause more precipitation.The lower reaches of the Yangtze River appear to receive more precipitation by means of the strong westerly water vapor flow transported from the "large triangle affecting the region".In years when the plateau summer monsoon is weak,these are opposite.The plateau monsoon is closely related to the intensity and position of the South Asian high,and the existence of a teleconnection pattern in the mid-upper levels suggests a possible linl~ge of the East Asian monsoon and the Indian monsoon to the plateau summer monsoon.

  9. The diverse crustal structure and magmatic evolution of the Manihiki Plateau, central Pacific

    Directory of Open Access Journals (Sweden)

    K. Hochmuth

    2014-07-01

    Full Text Available The Manihiki Plateau is a Large Igneous Province (LIP in the central Pacific. It was emplaced as part of the "Super-LIP" Ontong Java Nui and experienced fragmentation into three sub-plateaus, possibly during the break-up of Ontong Java Nui. The Manihiki Plateau is presumably the centerpiece of this "Super-LIP" and its investigation can therefore decipher the break-up mechanisms as well as the evolution of the plateau after its initial emplacement. By analyzing two seismic refraction/wide-angle reflection profiles crossing the two largest sub-plateaus of the Manihiki Plateau, the High Plateau and the Western Plateaus, we give new insights into their crustal structure and magmatic evolution. The High Plateau shows a crustal structure of 20 km thickness and a seismic P wave velocity distribution, which is comparable to other LIPs. The High Plateau experienced a strong secondary volcanism, which can be seen in relicts of seamount chain volcanism. The Western Plateaus on the other hand show no extensive secondary volcanism and are mainly structured by fault systems and sedimentary basins. A constant decrease in Moho depth (9–17 km is a further indicator of crustal stretching on the Western Plateaus. Those findings lead to the conclusion, that the two sub-plateaus of the Manihiki Plateau experienced a different magmatic and tectonic history. Whereas the High Plateau experienced a secondary volcanism, the Western Plateaus underwent crustal stretching during and after the break-up of Ontong Java Nui. This indicates, that the sub-plateaus of the Manihiki Plateau play an individual part in the break-up history of Ontong Java Nui.

  10. Analysis of turbulence characteristics over the northern Tibetan Plateau area

    Science.gov (United States)

    Li, M. S.; Ma, Y. M.; Ma, W. Q.; Hu, Z. Y.; Ishikawa, H.; Su, Z. B.; Sun, G. L.

    2006-07-01

    Based on CATOP/Tibet [Coordinated Enhanced Observing Period (CEOP) Asia-Australia Monsoon Project (CA-IMP) on the Tibetan Plateau) turbulent data collected at the Bujiao (BJ) site of the Nagqu area, the turbulent structure and transportation characteristics in the near surface layer during summer are analyzed. The main results show that the relationship between the normalized standard deviation of 3D wind speed and stability satisfies the similarity law tinder both unstable and stable stratifications. The relations of normalized standard deviation of temperature and specific humidity to stability only obey the "-1/3 power law." tinder unstable conditions. In the case of stable stratifications, their relations to stability are dispersing. The sensible heat dominates in the dry period, while in the wet period, the latent heat is larger than the sensible heat.

  11. Contrast Enhancement Using Brightness Preserving Histogram Plateau Limit Technique

    Directory of Open Access Journals (Sweden)

    K. Santhi

    2014-07-01

    Full Text Available Contrast enhancement is an important factor in the gray scale images. One of the widely accepted contrast enhancement method is the Histogram equalization (HE. HE achieves comparatively better performance on almost all types of image but sometimes produces excessive visual deterioration. The proposed Contrast Enhancement using Brightness Preserving Histogram Plateau Limit (CEBPHPL method provides better brightness preservation without allowing in excess of contrast improvement measure. This method decomposes the input image by computing the local maxima of the smoothed image using Gaussian filter which reduces the noise. Then the clipping process has been implemented which provides the good enhancement rate than the conventional methods. The experimental result of the proposed CEBPHPL is better than the existing methods.

  12. Motive force of Qinghai-Tibet Plateau moving to east

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A calculation formula on spherical pattern of Qinghai-Tibet plateau moving model is established. Tibet massif moves norward by east in speed of 28 mm/a, Ganshu-Qinghai massif moves to northeast in speed of 15 mm/a, Qomolangma Feng moves northward by a few east in speed of 35 ~42 mm/a. The low latitude perimeter is longer than the nigh latitude perimeter. When the Tibet massif moves northward, its latitude perimeter must be contracted and the Tibet massif must move eastward by Coriolis. Coriolis force is inertial in earth rotation. It makes the fall body turning to east and the rising block turning westward. In the Northern Hemisphere, it makes the northward body turning to east and the southward block turning to west.This is the reason why the tectonic zones of western Pacific are different from those of eastern Pacific.

  13. Plateau Inflation from Random Non-Minimal Coupling

    CERN Document Server

    Broy, Benedict J; Roest, Diederik

    2016-01-01

    A generic non-minimal coupling can push any higher-order terms of the scalar potential sufficiently far out in field space to yield observationally viable plateau inflation. We provide analytic and numerical evidence that this generically happens for a non-minimal coupling strength $\\xi$ of the order $N_e^2$. In this regime, the non-minimally coupled field is sub-Planckian during inflation and is thus protected from most higher-order terms. For larger values of $\\xi$, the inflationary predictions converge towards the sweet spot of PLANCK. The latter includes $\\xi\\simeq 10^4$ obtained from CMB normalization arguments, thus providing a natural explanation for the inflationary observables measured.

  14. Plateau inflation from random non-minimal coupling

    Energy Technology Data Exchange (ETDEWEB)

    Broy, Benedict J. [Deutsches Elektronen-Synchrotron DESY, Theory Group,22603 Hamburg (Germany); Coone, Dries [Van Swinderen Institute for Particle Physics and Gravity, University of Groningen,Nijenborgh 4, 9747 AG Groningen (Netherlands); Theoretische Natuurkunde,Vrije Universiteit Brussel and The International Solvay Institutes,Pleinlaan 2, B-1050 Brussels (Belgium); Roest, Diederik [Van Swinderen Institute for Particle Physics and Gravity, University of Groningen,Nijenborgh 4, 9747 AG Groningen (Netherlands)

    2016-06-20

    A generic non-minimal coupling can push any higher-order terms of the scalar potential sufficiently far out in field space to yield observationally viable plateau inflation. We provide analytic and numerical evidence that this generically happens for a non-minimal coupling strength ξ of the order N{sub e}{sup 2}. In this regime, the non-minimally coupled field is sub-Planckian during inflation and is thus protected from most higher-order terms. For larger values of ξ, the inflationary predictions converge towards the sweet spot of PLANCK. The latter includes ξ≃10{sup 4} obtained from CMB normalization arguments, thus providing a natural explanation for the inflationary observables measured.

  15. Plateau inflation from random non-minimal coupling

    Energy Technology Data Exchange (ETDEWEB)

    Broy, Benedict J. [DESY Hamburg (Germany). Theory Group; Coone, Dires [Groningen Univ. (Netherlands). Van Swinderen Inst. for Particle Physics and Gravity; Vrije Univ., Brussels (Belgium). Theoretische Natuurkunde; The International Solvay Institutes, Brussels (Belgium); Roest, Diederik [Groningen Univ. (Netherlands). Van Swinderen Inst. for Particle Physics and Gravity

    2016-06-15

    A generic non-minimal coupling can push any higher-order terms of the scalar potential sufficiently far out in field space to yield observationally viable plateau inflation. We provide analytic and numerical evidence that this generically happens for a non-minimal coupling strength ξ of the order N{sup 2}{sub e}. In this regime, the non-minimally coupled field is sub-Planckian during inflation and is thus protected from most higher-order terms. For larger values of ξ, the inflationary predictions converge towards the sweet spot of PLANCK. The latter includes ξ≅10{sup 4} obtained from CMB normalization arguments, thus providing a natural explanation for the inflationary observables measured.

  16. 12 kaBP lake environment on the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    李炳元; 王苏民; 朱立平; 李元芳

    2001-01-01

    The systemic analyses have been carried out in this paper to the paleolake shorelines, paleolake sediments and paleoclimatic proxies of 20 lakes, in which there were 12 kaBP dating data on the Tibetan Plateau. The results showed that the paleolake level had apparently risen during 14-11 kaBP, the glaciers melting period, in the Tibetan area and Northwest China. Especially, much more increasing amplitude supplied by thawy glaciers water occurred than in the best period of Holocene. The temperate-humid climate around 12 kaBP appeared in the Tibetan area and even in the whole China. This event may be compared with the Bolling/Allerod warm period which was reflected by Europe and Greenland ice core records. It showed that the B/A event was not a regional one in the North Atlantic area.

  17. Analysis of Turbulence Characteristics over the Northern Tibetan Plateau Area

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Based on CAMP/Tibet [Coordinated Enhanced Observing Period (CEOP) Asia-Australia Monsoon Project (CAMP) on the Tibetan Plateau] turbulent data collected at the Bujiao (BJ) site of the Nagqu area, the turbulent structure and transportation characteristics in the near surface layer during summer are analyzed. The main results show that the relationship between the normalized standard deviation of 3D wind speed and stability satisfies the similarity law under both unstable and stable stratifications.The relations of normalized standard deviation of temperature and specific humidity to stability only obey the "-1/3 power law" under unstable conditions. In the case of stable stratifications, their relations to stability are dispersing. The sensible heat dominates in the dry period, while in the wet period, the latent heat is larger than the sensible heat.

  18. Looking at the Spite plateau from a different perspective

    Science.gov (United States)

    Charbonnel, C.; Primas, F.

    Thanks to the accurate determination of the baryon density of the Universe by the recent cosmic microwave background experiments, updated predictions of the standard model of Big Bang nucleosynthesis yield the initial abundances of the primordial light elements with an unprecedented precision (Bennet et al. 2003; Spergel et al. 2003; Coc et al. 2004; Cyburt 2004). In the case of 7Li, the CMB+SBBN value is significantly higher than the generally reported abundances for Pop II stars along the Spite plateau. Here, we report on the very recent results we obtained by revisiting a large sample of literature Li data in halo stars that we assembled following some strict criteria on the quality of the original analyses published from the early 90s onwards.

  19. Land Desertification Monitoring on Tibetan Plateau Using Remote Sensing Technology

    Science.gov (United States)

    Liu, Z.; Zou, X.; Liu, H.

    2012-12-01

    As one of the serious ecological environmental problems of the Tibetan plateau, desertification has critically hampered the economic and social development in Tibet, so it is imperative to monitoring the desertification in Tibet area. Due to its 200 thousand km2 vast area and steep terrain, this paper uses multi-source remote sensing image to survey the current situation of land desertification in Tibetan plateau, and study dynamic desertification change on the 10 km2 land between Namucuo lake and Selincuo lake. Data of the 250 meters time-series MODIS-NDVI images, 30 m resolution Landsat TM images and 90 m SRTM DEM data were used. Through the analysis of the relationship between MODIS-NDVI, vegetation growth characteristics and vegetation vertical distribution, this paper chooses the MODIS-NDVI time series data and principal component analysis of the first band (PC1), vegetation coverage(VC), DEM and its derived slope data as indicators for desertification monitoring. Visual interpretation based on 30 m TM image is also used to classify each type of desertification. Using the high temporal resolution data, we can quickly obtain desertification hot spot areas then accurately distinguish each degree of desertification with high spatial resolution images. The results are: (1) The desertification area in Tibetan plateau in 2008 is 218,286 km2, which is 18.91% of the total area, and mainly distributed in the Ali region, next by Nagqu and Xigaze. The severe desertification land area is 8,866 km2 ( 4.06% of the desertified land), of which the mobile dune area is 3224 km2, heavy saline area is 5641 km2. Moderate desertified land area is 110,915 km2( 50.81% of the desertified land), of which semi-fixed sand dune area is 10,075 km2 and the bare sand area is 100,839 km2. Mild desertified land area is 98,504 km2 ( 45.12% of the desertified land), of which the fixed dune area is 4,177 km2 and the half bare gravel area is 94,326 km2. (2) By using GIS spatial analysis, westudied

  20. Ongoing speciation in the Tibetan plateau Gymnocypris species complex.

    Science.gov (United States)

    Zhang, Renyi; Peng, Zuogang; Li, Guogang; Zhang, Cunfang; Tang, Yongtao; Gan, Xiaoni; He, Shunping; Zhao, Kai

    2013-01-01

    Local adaptation towards divergent ecological conditions often results in genetic differentiation and adaptive phenotypic divergence. To illuminate the ecological distinctiveness of the schizothoracine fish, we studied a Gymnocypris species complex consisting of three morphs distributed across four bodies of water (the Yellow River, Lake Qinghai, the Ganzi River and Lake Keluke) in the Northeast Tibetan Plateau. We used a combination of mitochondrial (16S rRNA and Cyt b) and nuclear (RAG-2) genetic sequences to investigate the phylogeography of these morphs based on a sample of 277 specimens. Analysis of gill rakers allowed for mapping of phenotypic trajectories along the phylogeny. The phylogenetic and morphological analyses showed that the three sparsely rakered morphs were present at two extremes of the phylogenetic tree: the Yellow River morphs were located at the basal phylogenetic split, and the Lake Keluke and Ganzi River morphs at the peak, with the densely rakered Lake Qinghai morphs located between these two extremes. Age estimation further indicated that the sparsely rakered morphs constituted the oldest and youngest lineages, whereas the densely rakered morph was assigned to an intermediate-age lineage. These results are most compatible with the process of evolutionary convergence or reversal. Disruptive natural selection due to divergent habitats and dietary preferences is likely the driving force behind the formation of new morphs, and the similarities between their phenotypes may be attributable to the similarities between their forms of niche tracking associated with food acquisition. This study provides the first genetic evidence for the occurrence of convergence or reversal in the schizothoracine fish of the Tibetan Plateau at small temporal scales.

  1. Ongoing speciation in the Tibetan plateau Gymnocypris species complex.

    Directory of Open Access Journals (Sweden)

    Renyi Zhang

    Full Text Available Local adaptation towards divergent ecological conditions often results in genetic differentiation and adaptive phenotypic divergence. To illuminate the ecological distinctiveness of the schizothoracine fish, we studied a Gymnocypris species complex consisting of three morphs distributed across four bodies of water (the Yellow River, Lake Qinghai, the Ganzi River and Lake Keluke in the Northeast Tibetan Plateau. We used a combination of mitochondrial (16S rRNA and Cyt b and nuclear (RAG-2 genetic sequences to investigate the phylogeography of these morphs based on a sample of 277 specimens. Analysis of gill rakers allowed for mapping of phenotypic trajectories along the phylogeny. The phylogenetic and morphological analyses showed that the three sparsely rakered morphs were present at two extremes of the phylogenetic tree: the Yellow River morphs were located at the basal phylogenetic split, and the Lake Keluke and Ganzi River morphs at the peak, with the densely rakered Lake Qinghai morphs located between these two extremes. Age estimation further indicated that the sparsely rakered morphs constituted the oldest and youngest lineages, whereas the densely rakered morph was assigned to an intermediate-age lineage. These results are most compatible with the process of evolutionary convergence or reversal. Disruptive natural selection due to divergent habitats and dietary preferences is likely the driving force behind the formation of new morphs, and the similarities between their phenotypes may be attributable to the similarities between their forms of niche tracking associated with food acquisition. This study provides the first genetic evidence for the occurrence of convergence or reversal in the schizothoracine fish of the Tibetan Plateau at small temporal scales.

  2. Threshold friction velocity of soils within the Columbia Plateau

    Science.gov (United States)

    Sharratt, B. S.; Vaddella, V. K.

    Wind erosion only occurs when the friction velocity exceeds the threshold friction velocity (TFV) of the surface. The TFV of loessial soils found across the Columbia Plateau region of the U.S. Pacific Northwest is virtually unknown even though these soils are highly erodible and a source of atmospheric particulates that reduce air quality. The TFV's of a sandy loam and four silt loams collected from field sites in eastern Washington were determined by systematically measuring the temporal variation in wind speed, saltation activity, and PM10 (particles with an aerodynamic diameter of ⩽10 μm) and TSP (total suspended particulate matter) concentrations above the soil surface inside a wind tunnel. The erodible fraction of each soil, obtained by drying and screening the soil, was placed in a tray inside the wind tunnel. The TFV for the sandy loam was 0.139 m s-1 whereas the TFV for the four silt loams ranged from 0.180-0.239 m s-1. The sandy loam was aerodynamically smoother than that of the silt loams, possibly due to a smaller size fraction of larger soil aggregates or particles on the surface of the sandy loam. The TFV's measured in this study were lower than those previously observed in the field in the Columbia Plateau and also lower than the minimum TFV required to initiate erosion in some wind erosion models. While these TFV's are representative of the erodible soil fraction, the low TFV's may contribute to the occasional poor performance of wind erosion models in the region.

  3. Improving human plateaued motor skill with somatic stimulation.

    Directory of Open Access Journals (Sweden)

    Shintaro Uehara

    Full Text Available Procedural motor learning includes a period when no substantial gain in performance improvement is obtained even with repeated, daily practice. Prompted by the potential benefit of high-frequency transcutaneous electrical stimulation, we examined if the stimulation to the hand reduces redundant motor activity that likely exists in an acquired hand motor skill, so as to further upgrade stable motor performance. Healthy participants were trained until their motor performance of continuously rotating two balls in the palm of their right hand became stable. In the series of experiments, they repeated a trial performing this cyclic rotation as many times as possible in 15 s. In trials where we applied the stimulation to the relaxed thumb before they initiated the task, most reported that their movements became smoother and they could perform the movements at a higher cycle compared to the control trials. This was not possible when the dorsal side of the wrist was stimulated. The performance improvement was associated with reduction of amplitude of finger displacement, which was consistently observed irrespective of the task demands. Importantly, this kinematic change occurred without being noticed by the participants, and their intentional changes of motor strategies (reducing amplitude of finger displacement never improved the performance. Moreover, the performance never spontaneously improved during one-week training without stimulation, whereas the improvement in association with stimulation was consistently observed across days during training on another week combined with the stimulation. The improved effect obtained in stimulation trials on one day partially carried over to the next day, thereby promoting daily improvement of plateaued performance, which could not be unlocked by the first-week intensive training. This study demonstrated the possibility of effectively improving a plateaued motor skill, and pre-movement somatic stimulation

  4. Pv rural electrification programme at the Bolivian high plateau

    Energy Technology Data Exchange (ETDEWEB)

    Lorenzo, E.; Aguilera, J. [Instituto de Energia Solar, ETSI Telecomunicacion, (Spain)

    1995-12-31

    Since 1988 the Institute of Solar Energy of the Universidad Politecnica de Madrid is carrying out a pv rural electrification programme at the Bolivian high plateau. This programme has been focused in three aspects: the domestic electrification, users participation and transfer technology. At present, there are about 1,500 electrified dwellings distributed in the Bolivian high plateau. We have got deep knowledge about life style and organization of the aymara Indians who are the inhabitants of the working zone. We think that this knowledge can be very useful for a large scale introduction of PV solar energy in this region. Finally, we present a new way to transfer PV technology to developing countries. Thanks to this programme a group of aymara Indians is able to manufacture charge regulators and electronic ballast to use in the PV installations of the programme. [Espanol] Desde 1988 el Instituto de Energia Solar de la Universidad Politecnica de Madrid esta llevando a cabo un programa fotovoltaico de electrificacion rural en la altiplanicie Boliviana. Este programa ha sido enfocado a tres aspectos: la electrificacion domestica, la participacion de los usuarios y la transferencia de la tecnologia. Actualmente, hay alrededor de 1500 conjuntos habitacionales electrificados distribuidos en la altiplanicie Boliviana. Hemos obtenido un profundo conocimiento del estilo de vida y de la organizacion de los indios aymara que son los habitantes de la zona de trabajo. Pensamos que este conocimiento puede ser muy util para una introduccion en gran escala de la energia solar fotovoltaica en esta region. Finalmente, presentamos una nueva forma de transferir la tecnologia fotovoltaica a paises en desarrollo. Gracias a este programa un grupo de indios aymara pueden fabricar reguladores de carga y balastros electronicos para ser usados en instalaciones fotovoltaicas del programa.

  5. Relationship between gullying and landslides within the Barlad Plateau, Romania

    Science.gov (United States)

    Niacsu, Lilian; Ionita, Ion

    2016-04-01

    Located in the eastern Romania and extending on 8200 km2 the Barlad Plateau is considered the most typical subunit of the Moldavian Plateau. The sedimentary Miocene-Pliocene clay-sandy layers, inter-bedded with shallow sandstone and limestone are gently dipping toward S-SE as homoclinal structure. Land degradation through soil erosion, gullying and landslides represent the most important environmental threat in the region. By using both the classical research methods such as repeated field surveys and mapping, mathematical-statistical processing as well as the present-day methods based on the GIS software it was possible to precisely measure and evaluate the gully erosion rates and triggered landslides during the last two centuries, especially with a very high accuracy since 1960. Results have indicated that the landslide development is strongly controlled by gullying. Generally, by combining the areal growth of both gullying and new landslides within the selected study catchments, it is noticeable that 62 % of the total recent land degradation occurred during the last 55 years, with the remainder pre-1960. In addition, half of the gully areal growth occurred since 1961 but the new triggered landslides amount over three-quarters of the total area under landslides. This asymmetrical distribution reveals that usually a preparing time lag of tens of years is required for triggering landslides by gullying and this pattern depicts the common mechanism for landslide development. Acknowledgements: This work was partly supported by a grant from the Romanian National Authority for Scientific Research, CNDI-UEFISCDI, Project number PN-II-PT-PCCA-2011-3.2-0975.

  6. Trauma capacity in the central plateau department of Haiti.

    Science.gov (United States)

    Dewberry, Lindel; McCullough, Chelsea; Goss, Jonathan; Hugar, Lee A; Dente, Christopher J; Sharma, Jyotirmay

    2014-11-01

    Surgical burden is a large and neglected global health problem in low- and middle-income countries. With the increasing trauma burden, the goal of this study was to evaluate the trauma capacity of hospitals in the central plateau of Haiti. The World Health Organization Emergency and Essential Surgical Care survey was adapted with a focus on trauma capacity. Interviewers along with translators administered the survey to key hospital staff. Seven hospitals in the region were surveyed. Of the hospitals surveyed, 3/7 had functioning surgical facilities. None of the hospitals had trauma registries. 71% of the hospitals had no formal trauma guidelines. 2/7 hospitals had a general surgeon available 100% of the time. All surgical facilities had oxygen cylinders available 100% of the time, but three of the primary level hospitals only had it available 51%-90% of the time. Intubation equipment was available at 57% of the facilities. Ventilators were only available in the operating room. Only the largest hospital had a computed tomography scanner. Other hospitals (66%) had a functioning x-ray machine 76%-90% of the time. Hospitals (57%) had an ultrasound machine. The most common reasons for referral were lack of appropriate facilities and supplies at the primary level care centers or lack of trained personnel at higher-level facilities. Trauma capacity in the central plateau of Haiti is limited. There is a great need for more personnel, trauma training at all staff levels, emergency care guidelines, trauma registries, and imaging equipment and training, specifically in ultrasonography. To accomplish this, coordination is needed between the Haitian government and local and international nongovernmental organizations. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. On edge melting under the Colorado Plateau margin

    Science.gov (United States)

    Rudzitis, Sean; Reid, Mary R.; Blichert-Toft, Janne

    2016-07-01

    Asthenosphere beneath the relatively thin lithosphere of the Basin and Range province appears to be juxtaposed in step-like fashion against the Colorado Plateau's thick lithospheric keel. Primary to near-primary basalts are found above this edge, in the San Francisco-Morman Mountain volcanic fields, north central Arizona, western USA. We show that at least two distinct peridotite-dominated mantle end-members contributed to the origin of the basalts. One has paired Nd and Hf isotopic characteristics that cluster near the mantle array and trace element patterns as expected for melts generated in the asthenosphere, possibly in the presence of garnet. The second has isotopic compositions displaced above the ɛHf - ɛNd mantle array which, together with its particular trace element characteristics, indicate contributions from hydrogenous sediments and/or melt (carbonatite or silicate)-related metasomatism. Melt equilibration temperatures obtained from Si- and Mg-thermobarometry are mostly 1340-1425°C and account for the effects of water (assumed to be 2 wt.%) and estimated CO2 (variable). Melt equilibration depths cluster at the inferred location of the lithosphere-asthenosphere boundary at ˜70-75 km beneath the southwestern margin of the Colorado Plateau but scatter to somewhat greater values (˜100 km). Melt generation may have initiated in or below the garnet-spinel facies transition zone by edge-driven convection and continued as mantle and/or melts upwelled, assimilating and sometimes equilibrating with shallower contaminated mantle, until melts were finally extracted.

  8. Seismic source characterization for the Shillong Plateau in Northeast India

    Science.gov (United States)

    Baro, Olympa; Kumar, Abhishek

    2017-09-01

    The present study aims at understanding the seismotectonic province of the Shillong Plateau (SP) by identifying the potential seismic source zones within a radius of 500 km from the centre of the SP. From existing literature and earthquake (EQ) data, the seismotectonic region is found to vary in terms of seismicity, tectonic features, geology, thickness of overburden, rupture characteristics and rate of movement. Thus, entire 500-km-radius seismotectonic region is divided into four seismic source zones: namely (1) the Shillong Plateau-Assam Valley Zone (SP-AVZ), (2) the Indo-Burma Ranges Zone (IBRZ), (3) the Bengal Basin Zone (BBZ) and (4) the Eastern Himalaya Zone (EHZ). EQ catalogues for each source zone is analysed for completeness of magnitude and time. Seismic parameter b estimated using a maximum likelihood method is found to be 0.91 ± 0.03, 0.94 ± 0.02, 0.80 ± 0.03 and 0.89 ± 0.03 for the SP-AVZ, IBRZ, BBZ and EHZ, respectively. In addition, the maximum likelihood method is used to estimate the mean annual activity rate, maximum possible magnitude ( m max), return period and probability of exceedance for the four zones. The b values estimated suggest that the BBZ is seismically more active; however, the rate of occurrence of EQs is highest in the IBRZ. Findings from this study are an indication of the relative contribution from each of the four seismic source zones towards a seismic hazard of the SP.

  9. Spatio-temporal dynamics of evapotranspiration on the Tibetan Plateau from 2000 to 2010

    Science.gov (United States)

    Song, Lulu; Zhuang, Qianlai; Yin, Yunhe; Zhu, Xudong; Wu, Shaohong

    2017-01-01

    Evapotranspiration (ET) is a key process of the climate system because it links water, energy and carbon cycles. In this study we modified a Penman-Monteith based algorithm to estimate ET on the Tibetan Plateau at a 1 km spatial resolution for the period 2000-2010 using meteorological and satellite remote sensing data. The results showed that the average annual ET on the Tibetan Plateau was 350.3 mm year-1 and decreased from the southeast toward the northwest. The highest ET value was found in open water bodies (680.9 mm year-1) and the lowest ET value was found in open shrubland (254.0 mm year-1). Overall, the inter-annual ET decreased from 2000 to 2010 and there was significant negative ET trend over 42% of the region, primarily in the northwest of the Tibetan Plateau. Relative humidity was the dominant factor in controlling long-term variations of ET in the arid northwest plateau. But under moist conditions, leaf area index or temperature drove ET. In addition, P-ET on the Tibetan Plateau significantly increased and about 37% of the region showed strong positive P-ET trend primarily in the central of the Tibetan Plateau. The positive P-ET trend in four seasons suggested that the Tibetan Plateau might have become wetter during the past decade.

  10. Tibetan plateau river incision inhibited by glacial stabilization of the Tsangpo gorge.

    Science.gov (United States)

    Korup, Oliver; Montgomery, David R

    2008-10-09

    A considerable amount of research has focused on how and when the Tibetan plateau formed in the wake of tectonic convergence between India and Asia. Although far less enquiry has addressed the controls on river incision into the plateau itself, widely accepted theory predicts that steep fluvial knick points (river reaches with very steep gradients) in the eastern Himalayan syntaxis at the southeastern plateau margin should erode rapidly, driving a wave of incision back into the plateau. Preservation of the plateau edge thus presents something of a conundrum that may be resolved by invoking either differential rock uplift matching erosional decay, or other mechanisms for retarding bedrock river incision in this region where high stream power excludes the potential for aridity as a simple limit to dissection of the plateau. Here we report morphologic evidence showing that Quaternary depression of the regional equilibrium line altitude, where long-term glacier mass gain equals mass loss, was sufficient to repeatedly form moraine dams on major rivers: such damming substantially impeded river incision into the southeastern edge of the Tibetan plateau through the coupled effects of upstream impoundment and interglacial aggradation. Such glacial stabilization of the resulting highly focused river incision centred on the Tsangpo gorge could further contribute to initiating and accentuating a locus of rapid exhumation, known as tectonic anaeurysm.

  11. Lightning activity on the central Tibetan Plateau and its response to convective available potential energy

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Lightning flash activities on the central Tibetan Plateau have been studied by using the satellite-based Lightning Imaging Sensor (LIS) database from January 1998 to July 2002. The lightning activity shows a clear diurnal variation on the central Plateau. The peak lightning activity appears at about 17︰00 which is 3 h earlier than that in Jingzhou, Hubei in the same latitude belt nearby, indicating that the lightning activity is a sensitive indicator of solar heating on the Plateau. The lightning discharge is weaker on the Plateau than Jingzhou, Hubei and other low-altitude continental regions because of the lower convective available potential energy (CAPE) on the Plateau. The CAPE on the Plateau is 12 times lower than that in Jingzhou, Hubei, and 20 times lower than that in the sea-level region, such as Guangzhou and Florida. However, the sensitivity of lightning activity to CAPE changes on the Plateau is up to 30 times more sensitive than other prominent low-altitude regions.

  12. Deep Mechanical Background for the Cenozoic Volcanism in the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    Xiong Xiong; Wang Jiye; Teng Jiwen

    2005-01-01

    The principle prerequisite for the formation of a volcano is the generation of a channel for magma transportation. There is little research on the deep mechanical mechanism for the formation of a magma transportation channel in the Tibetan plateau.Based on the subcrustal mantle convection-generated stress field inversed by gravity anomalies, together with its relationship to the Cenozoic volcanism in the plateau, and the mechanism of crustal fracture formation, as well as the numerical results of the evolution of mantle convection beneath the plateau, this paper investigates the deep mechanical mechanism for the formation of a magma transportation channel in the Tibetan plateau. There are two significant extensional convection-generated stress zones beneath the plateau, in which the volcanic rocks in the central and northern parts of the plateau are distributed. The Linzizong volcanism in southern Tibet correlates the upwelling mantle flow prior to the India-Asia collision or during the early stage of the collision. The magnitude of the stress is ~100 MPa, which is the same order of force that causes crustal fractures. The evidence implies that the mantle convection-generated stress is one of the principle causes of crustal fractures, and furthermore, the formation of the magma transportation channel in the Tibetan plateau.

  13. Geodynamics of oceanic plateau and plume head accretion and their role in Phanerozoic orogenic systems of China

    Institute of Scientific and Technical Information of China (English)

    Peter G. Betts; Louis Moresi; Meghan S. Miller; David Willis

    2015-01-01

    We present three 3D numerical models of deep subduction where buoyant material from an oceanic plateau and a plume interact with the overriding plate to assess the influence on subduction dynamics, trench geometry, and mechanisms for plateau accretion and continental growth. Transient instabilities of the convergent margin are produced, resulting in:contorted trench geometry;trench migration parallel with the plate margin; folding of the subducting slab and orocline development at the convergent margin;and transfer of the plateau to the overriding plate. The presence of plume material beneath the oceanic plateau causes flat subduction above the plume, resulting in a“bowed”shaped subducting slab. In plateau-only models, plateau accretion at the edge of the overriding plate results in trench migration around the edge of the plateau before subduction is re-established directly behind the trailing edge of the plateau. The plateau shortens and some plateau material subducts. The presence of buoyant plume material beneath the oceanic plateau has a profound influence on the behaviour of the convergent margin. In the plateau þ plume model, plateau accretion causes rapid trench advance. Plate convergence is accommodated by shearing at the base of the plateau and shortening in the overriding plate. The trench migrates around the edge of the plateau and subduction is re-established well behind the trailing edge of the plateau, effectively embedding the plateau into the overriding plate. A slab window forms beneath the accreted plateau and plume material is transferred from the subducting plate to the over-riding plate through the window. In all of the models, the subduction zone maintains a relatively stable configuration away from the buoyancy anomalies within the downgoing plate. The models provide a dynamic context for plateau and plume accretion in Phanerozoic accretionary orogenic systems such as the East China Orogen and the Central Asian Orogen (Altiads), which

  14. Genetic evidence of paleolithic colonization and neolithic expansion of modern humans on the tibetan plateau.

    Science.gov (United States)

    Qi, Xuebin; Cui, Chaoying; Peng, Yi; Zhang, Xiaoming; Yang, Zhaohui; Zhong, Hua; Zhang, Hui; Xiang, Kun; Cao, Xiangyu; Wang, Yi; Ouzhuluobu; Basang; Ciwangsangbu; Bianba; Gonggalanzi; Wu, Tianyi; Chen, Hua; Shi, Hong; Su, Bing

    2013-08-01

    Tibetans live on the highest plateau in the world, their current population size is approximately 5 million, and most of them live at an altitude exceeding 3,500 m. Therefore, the Tibetan Plateau is a remarkable area for cultural and biological studies of human population history. However, the chronological profile of the Tibetan Plateau's colonization remains an unsolved question of human prehistory. To reconstruct the prehistoric colonization and demographic history of modern humans on the Tibetan Plateau, we systematically sampled 6,109 Tibetan individuals from 41 geographic populations across the entire region of the Tibetan Plateau and analyzed the phylogeographic patterns of both paternal (n = 2,354) and maternal (n = 6,109) lineages as well as genome-wide single nucleotide polymorphism markers (n = 50) in Tibetan populations. We found that there have been two distinct, major prehistoric migrations of modern humans into the Tibetan Plateau. The first migration was marked by ancient Tibetan genetic signatures dated to approximately 30,000 years ago, indicating that the initial peopling of the Tibetan Plateau by modern humans occurred during the Upper Paleolithic rather than Neolithic. We also found evidences for relatively young (only 7-10 thousand years old) shared Y chromosome and mitochondrial DNA haplotypes between Tibetans and Han Chinese, suggesting a second wave of migration during the early Neolithic. Collectively, the genetic data indicate that Tibetans have been adapted to a high altitude environment since initial colonization of the Tibetan Plateau in the early Upper Paleolithic, before the last glacial maximum, followed by a rapid population expansion that coincided with the establishment of farming and yak pastoralism on the Plateau in the early Neolithic.

  15. Extensional Seismogenic Stress and Tectonic Movement on the Central Region of the Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Jiren Xu

    2009-01-01

    Full Text Available Various earthquake fault types, mechanism solutions and stress fields, as well as GPS and geothermal data are analyzed for the study of the crustal movements on the Tibetan plateau and their tectonic implications. The results show that a lot of the normal faulting type-event concentrated at altitudes greater than 4000 m on the central Tibetan plateau. The altitudes concentrating normal faulting type-events can be zoned two parts: the western part, the Lhasa block, and the eastern part, the Qiangtang-Changdu region. The azimuths of T-axes are in a general E-W direction in the Lhasa block and NW-SE or NNW-SSE in the Qiangtang-Changdu region at the altitudes of the Tibetan plateau. The tensional stresses in E-W direction and NW-SE direction predominate normal faulting earthquake occurrence in the Lhasa block and the Qiangtang-Changdu region, respectively. The slipping displacements of the normal-faulting-type events have great components in near E-W direction and NW-SE direction in the Lhasa block and the Qiangtang-Changdu region, respectively. The extensions are probably an eastward or southeastward extensional motion, being mainly tectonic activity phenomena in the plateau altitudes. The extensional motions due to normal-fault earthquakes are important tectonic activity regimes on the high altitudes of the plateau. The easterly crustal extensions on the plateau are attributable to the gravitational collapse of the high plateau and eastward extrusion of hotter mantle materials beneath the eastern boundary of the plateau. Numbers of thrust-fault and strike-slip-fault earthquakes with strong compressive stress in a general NNE-SSW direction occur on the edges of the plateau.

  16. Numerical simulation of GPS observed clockwise rotation around the eastern Himalayan syntax in the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    CAO dianLing; SHI YaoLin; ZHANG Huai; WANG Hui

    2009-01-01

    From Global Position System (GPS) measurements,there is a clockwise rotation around the eastern Himalayan syntax in the Tibetan Plateau.This phenomenon is difficult to be interpreted by simple two-dimensional modeling from a geodynamic point of view.Because of the extremely thick crust and the lower crust with relatively high temperature in the Tibetan Plateau,the lithospheric rheology in Tibet and surrounding areas present a complex structure,in general,the tectonic structure of the Tibetan Plateau consists of brittle upper crust,ductile lower crust,high viscosity lithospheric upper mantle,and low viscosity asthenosphere,the same as the case in many other continental regions.However,the lower crust in the Tibetan Plateau is much more ductile with a lower viscosity than those of its sur-roundings at the same depth,and the effective viscosity is low along the collision fault zone.In this study,we construct a three-dimensional Maxwell visco-elastic model in spherical coordinate system,and simulate the deformation process of the Tibetan Plateau driven by a continuous push from the Indian plate.The results show that the existence of the soft lower crust under the plateau makes the entire plateau uplift as a whole,and the Himalayas and the eastern Himalayan syntax uplift faster.Since the lower crust of surrounding blocks is harder except in the southeastern corner where the high-temperature material is much softer and forms an exit channel for material transfer,after the whole plateau reaches a certain height,the lower crustal and upper mantle material begins to move eastward or southeastward and drag the upper crust to behave same way.Thus,from the macroscopic point of view,a relative rigid motion of the plateau with a clockwise rotation around the eastern Himalayan syntax is developed.

  17. Characteristics of land-atmosphere energy and turbulent fluxes over the plateau steppe in central Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    MaoShan Li; ZhongBo Su; YaoMing Ma; XueLong Chen; Lang Zhang; ZeYong Hu

    2016-01-01

    The land-atmosphere energy and turbulence exchange is key to understanding land surface processes on the Tibetan Plateau (TP). Using observed data for Aug. 4 to Dec. 3, 2012 from the Bujiao observation point (BJ) of the Nagqu Plateau Climate and Environment Station (NPCE-BJ), different characteristics of the energy flux during the Asian summer monsoon (ASM) season and post-monsoon period were analyzed. This study outlines the impact of the ASM on energy fluxes in the central TP. It also demonstrates that the surface energy closure rate during the ASM season is higher than that of the post-monsoon period. Footprint modeling shows the distribution of data quality assessments (QA) and quality controls (QC) surrounding the observation point. The measured turbulent flux data at the NPCE-BJ site were highly rep-resentative of the target land-use type. The target surface contributed more to the fluxes under unstable conditions than under stable conditions. The main wind directions (180° and 210°) with the highest data density showed flux contributions reaching 100%, even under stable conditions. The lowest flux contributions were found in sectors with low data density, e.g., 90.4% in the 360° sector under stable conditions during the ASM season. Lastly, a surface energy water balance (SEWAB) model was used to gap-fill any absent or corrected turbulence data. The potential simulation error was also explored in this study. The Nash-Sutcliffe model efficiency coefficients (NSEs) of the observed fluxes with the SEWAB model runs were 0.78 for sensible heat flux and 0.63 for latent heat flux during the ASM season, but unrealistic values of−0.9 for latent heat flux during the post-monsoon period.

  18. Prediction of the trend of total column ozone over the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    刘煜; 李维亮; 周秀骥

    2001-01-01

    By using 2-D chemical model, the trend of total column ozone over the Tibetan Plateau is simulated. The results show that from 1980 to 1993, the total column ozone over the Tibetan Plateau decreases; after 1995, it starts to recover. But until 2050, it will not still reach the level of 1980 total column ozone. Under Tibetan special circulation, its total column ozone recovers more rapidly than zonal mean. Therefore, the Tibetan special meridional circulation is not a main reason why the total column ozone over the Tibetan Plateau decreases more strongly than zonal mean.

  19. Analysis of Mechanism of Tibetan Plateau Vortex Frequency Differences between Strong and Weak MJO Periods

    Science.gov (United States)

    Li, Guoping; Zhao, Fuhu

    2017-04-01

    There are many unique weather systems over the Tibetan Plateau (TP). Among them, the TP vortex (TPV for short) is representative of the low air pressure weather systems. The generation, development and eastward propagation of the TPV is usually accompanied by precipitation, strong winds, thunderstorms and other weather processes, resulting in a series of extreme weather events over the TP and the Sichuan-Chongqing basin where is the downstream of the plateau. Some TPVs, which move from the plateau to the east and develop strongly, even affect a wide range of China's eastern region. NCEP/DOE reanalysis data, OLR data from NOAA, the Australian Meteorological Bureau Real-time Multivariate MJO index, and Tibetan Plateau vortex (TPV) statistical data from the Institute of Plateau Meteorology, are used to discuss the modulation of the TPV by the MJO. Wavelet analysis and composite analysis are the methods used. The results show that: (1) The MJO plays an important role in modulating the TPV, for the number of TPVs generated in strong MJO periods is three times more than in weak periods. (2) During strong (weak) MJO periods, the Tibetan Plateau is in control of a low-frequency, low-pressure cyclone (high-pressure anticyclone) system, and thus the atmospheric circulation conditions over the plateau are conducive (not conducive) to the generation of TPVs. (3) During strong (weak) MJO periods, southerly (northerly) winds prevail in the east of the plateau, but northerly (southerly) winds in the west. Over the northern part of the plateau, easterly (westerly) flow is predominant, while westerly (easterly) flow prevails over the south, thus conducive (not conducive) to the formation of cyclonic circulation (i.e., TPVs) at low altitude over the plateau. (4) In strong MJO periods, water vapor is relatively less abundant over most of the plateau, which is not conducive to the generation of TPVs; however, moisture transported by the south branch trough and the low-frequency, high

  20. Experimental study on the repair of tibial plateau defect

    Institute of Scientific and Technical Information of China (English)

    XU Hai-lin; HAN Na; KOU Yu-hui; WANG Yan-hua; ZHANG Hong-bo; JIANG Bao-guo

    2012-01-01

    Objective: To evaluate the effect of autograft bone,allograft bone,calcium sulfate bone cement,and calcium phosphate bone cement on the repair of tibial plateau defect in rabbits.Methods: We used autograft bone,allograft bone,calcium sulfate bone cement,and calcium phosphate bone cement to repair tibial plateau defect in rabbits.Gross and histologic observations,X-ray examination,and biomechanical test were conducted at 1,2,4,8 weeks after operation.Results: X-ray examination found that the bone density was evidently reduced in calcium sulfate group at 8 weeks after operation; there were no marked changes in other groups.The maximal load measurements showed that autograft and allograft groups were greater than calcium sulfate and calcium phosphate groups at 1 and 2 weeks after operation.However at 4 and 8 weeks after operation,no significant difference was found among the four groups.In autograft and allograft groups,there was no significant difference in biomechanical intensity at 2,4,and 8 weeks,but it was significantly higher than that at 1 week.In calcium sulfate and calcium phosphate groups,the outcome was ranked in descending order as 1 week< 2 week< 4 week =8week.Histologic examination found a great amount of new bones at 8 week in both autograft and allograft groups.In calcium sulfate group,calcium sulfate was almost absorbed and there were numerous bone trabeculations.There was a large amount of unabsorbed calcium phosphate in calcium phosphate group.Conclusion: At 1-2 weeks postoperatively,the biomechanical intensity is higher in autograft and allograft groups than calcium sulfate and calcium phosphate groups,but after 4-8 weeks,there is no significant difference among groups.At 1-2 weeks,the biomechanical intensity in all groups is increased,but at 4-8 weeks,there is no significant increase.The rates of absorption and bone formation are quicker in calcium sulfate group than calcium phosphate group.

  1. Experimental study on the repair of tibial plateau defect

    Directory of Open Access Journals (Sweden)

    XU Hai-lin

    2012-11-01

    Full Text Available 【Abstract】 Objective: To evaluate the effect of autograft bone, allograft bone, calcium sulfate bone cement, and calcium phosphate bone cement on the repair of tibial plateau defect in rabbits. Methods: We used autograft bone, allograft bone, cal-cium sulfate bone cement, and calcium phosphate bone ce-ment to repair tibial plateau defect in rabbits. Gross and histo-logic observations, X-ray examination, and biomechanical test were conducted at 1, 2, 4, 8 weeks after operation. Results: X-ray examination found that the bone den-sity was evidently reduced in calcium sulfate group at 8 weeks after operation; there were no marked changes in other groups. The maximal load measurements showed that autograft and allograft groups were greater than calcium sulfate and calcium phosphate groups at 1 and 2 weeks after operation. However at 4 and 8 weeks after operation, no significant difference was found among the four groups. In autograft and allograft groups, there was no significant difference in biomechanical intensity at 2, 4, and 8 weeks, but it was significantly higher than that at 1 week. In cal-cium sulfate and calcium phosphate groups, the outcome was ranked in descending order as 1 week< 2 week< 4 week =8 week. Histologic examination found a great amount of new bones at 8 week in both autograft and allograft groups. In calcium sulfate group, calcium sulfate was almost absorbed and there were numerous bone trabeculations. There was a large amount of unabsorbed calcium phosphate in calcium phosphate group. Conclusion: At 1-2 weeks postoperatively, the biome-chanical intensity is higher in autograft and allograft groups than calcium sulfate and calcium phosphate groups, but after 4-8 weeks, there is no significant difference among groups. At 1-2 weeks, the biomechanical intensity in all groups is increased, but at 4-8 weeks, there is no significant increase. The rates of absorption and bone formation are quicker in calcium sulfate group than

  2. Quality characterization of Cretaceous coal from the Colorado Plateau coal assessment study area, 2000 (cpchmg)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This is a shapefile and ARC/INFO point coverage of coal geochemistry in the Colorado Plateau. This GIS layer was created from the U.S. Geological Survey's USCHEM...

  3. The active southwest margin of the Colorado Plateau: uplift of mantle origin

    Science.gov (United States)

    Parsons, T.; McCarthy, J.

    1995-01-01

    During Cenozoic time, the Colorado Plateau was raised about 2km above sea level. The most-recent and best-documented uplift of the plateau (~1km) has been concentrated at its southwest margin between 6 and 1 Ma, whereas the eastern Colorado Plateau may have been at high elevations since Eocene time. To better understand the recent tectonic activity at the southwest margin of the Colorado Plateau, we compile detailed crustal thickness and density information from seismic and gravity data for a region that includes northwest Arizona and the southern tip of Nevada. This information is used to isolate the mantle contribution to uplift. We speculate that uplift may result from subduction-related thinning of the continental lithosphere. -from Authors

  4. Observation of the Zero Hall Plateau in a Quantum Anomalous Hall Insulator

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Yang; Feng, Xiao; Ou, Yunbo; Wang, Jing; Liu, Chang; Zhang, Liguo; Zhao, Dongyang; Jiang, Gaoyuan; Zhang, Shou-Cheng; He, Ke; Ma, Xucun; Xue, Qi-Kun; Wang, Yayu

    2015-09-16

    We report experimental investigations on the quantum phase transition between the two opposite Hall plateaus of a quantum anomalous Hall insulator. We observe a well-defined plateau with zero Hall conductivity over a range of magnetic field around coercivity when the magnetization reverses. The features of the zero Hall plateau are shown to be closely related to that of the quantum anomalous Hall effect, but its temperature evolution exhibits a significant difference from the network model for a conventional quantum Hall plateau transition. We propose that the chiral edge states residing at the magnetic domain boundaries, which are unique to a quantum anomalous Hall insulator, are responsible for the novel features of the zero Hall plateau.

  5. A numerical modelling study on the processes of uplift and planation of the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    董文杰; 汤懋苍

    1997-01-01

    The Tibetan Plateau has experienced a number of processes of uplift and planation alternately since about 45 Ma B. P. when it began to raise. A differential equation model for describing the Plateau altitude variation with time is formulated on the basis of previous field studies and a theoretical hypothesis: if palaeomagnetic polarity is positive, the convective activity in the earth is strong; orogenic movement is violent; and the raising velocity of the Plateau is high and vice versa . The analytical solution of the equation is obtained. The altitude variation from the beginning of the Plateau uplift to present is computed through using the geomagnetic polarity reversals timing series and interstellar atomic hydrogen concentration data. A comparison between the model results and the field studies indicates that the former is quite similar to the latter. The model results are able to basically reproduce the alternating processes of uplift and planation of the plate geological history. In the present m

  6. Fixation of tibial plateau fractures with synthetic bone graft versus natural bone graft: a comparison study.

    LENUS (Irish Health Repository)

    Ong, J C Y

    2012-06-01

    The goal of this study was to determine differences in fracture stability and functional outcome between synthetic bone graft and natural bone graft with internal fixation of tibia plateau metaphyseal defects.

  7. Understanding the Formation of the Ontong Java Plateau Using Full Waveform Tomography

    Science.gov (United States)

    Covellone, B. M.; Savage, B.; Shen, Y.

    2012-12-01

    Prevailing hypotheses on the origin and evolution of the Ontong Java Plateau (OJP) do not sufficiently address all of the geophysical and geochemical observations. A more complete appraisal of the upper mantle beneath the plateau will unravel the plateau's 120Ma complex history and formation. Anomalously slower wave speeds have been observed extending to depths greater than 300 km beneath the plateau. We investigate this anomalous wave speed structure using an iterative full-waveform tomography approach. An initial 3-dimensional wave speed model is determined from ambient noise data for periods between 25 and 200 seconds; earthquake data is then used to increase crossing ray paths, improve resolution and localize wave speed structures. The combination of datasets allows us to best exploit the limited station distribution in the Pacific and better image upper mantle wave speed structures, key to understanding the current state of the OJP and hypotheses about its formation.

  8. A study of the bone healing kinetics of plateau versus screw root design titanium dental implants.

    LENUS (Irish Health Repository)

    Leonard, Gary

    2009-03-01

    This study was designed to compare the bone healing process around plateau root from (PRF) and screw root from (SRF) titanium dental implants over the immediate 12 week healing period post implant placement.

  9. Variation of soil hydraulic properties with alpine grassland degradation in the eastern Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    T. Pan

    2017-05-01

    hydrological effects of vegetation degradation. Further hydrological modelling studies in the Tibetan Plateau and similar regions are recommended to understand the effects of degraded alpine swamp meadows on soil hydraulic properties.

  10. Assessment of contamination in caves located at the Ozark Plateau National Wildlife Refuge, Oklahoma

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Ozark Plateau National Wildlife Refuge (Refuge) is located in east central Oklahoma; a sizeable portion of the Refuge is also located along Spavinaw Creek, near...

  11. Carbon sequestration function of check-dams: a case study of the Loess plateau in China.

    Science.gov (United States)

    Wang, Yafeng; Chen, Liding; Gao, Yang; Wang, Shuai; Lü, Yihe; Fu, Bojie

    2014-11-01

    Check-dams are the most common structures for controlling soil erosion in the Loess Plateau. However, the effect of check-dams on carbon sequestration, along with sediment transport and deposition, has not been assessed over large areas. In this study, we evaluated the carbon sequestration function of check-dams in the Loess Plateau. The results indicate that there were approximately 11 000 check-dams distributed in the Loess Plateau, with an estimate of the amount of sediment of 21 × 10⁹ m³ and a soil organic carbon storage amount of 0.945 Pg. Our study reveals that check-dams in the Loess Plateau not only conserve soil and water but also sequester carbon.

  12. Element concentrations in surface soils of the Coconino Plateau, Grand Canyon region, Coconino County, Arizona

    Science.gov (United States)

    Van Gosen, Bradley S.

    2016-09-15

    This report provides the geochemical analyses of a large set of background soils collected from the surface of the Coconino Plateau in northern Arizona. More than 700 soil samples were collected at 46 widespread areas, sampled from sites that appear unaffected by mineralization and (or) anthropogenic contamination. The soils were analyzed for 47 elements, thereby providing data on metal concentrations in soils representative of the plateau. These background concentrations can be used, for instance, for comparison to metal concentrations found in soils potentially affected by natural and anthropogenic influences on the Coconino Plateau in the Grand Canyon region of Arizona.The soil sampling survey revealed low concentrations for the metals most commonly of environmental concern, such as arsenic, cobalt, chromium, copper, mercury, manganese, molybdenum, lead, uranium, vanadium, and zinc. For example, the median concentrations of the metals in soils of the Coconino Plateau were found to be comparable to the mean values previously reported for soils of the western United States.

  13. [Territory and health: Antônio Pimentel's study on the Central Plateau].

    Science.gov (United States)

    Vergara, Moema de Rezende

    2008-01-01

    The article presents a report by Antônio Pimentel, physician with the 1892 Central Plateau Exploratory Commission, and analyzes its closing section, entitled "Pathology," which addresses the relations between health and the settlement of the Brazilian territory.

  14. Variations of stable isotopic compositions in precipitation on the Tibetan Plateau and its adjacent regions

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    There is no temperature effect in the southern Tibetan Plateau and South Asia to the south of the Tanggula Mountains. Amount effect has been observed at a few sampling stations accounting for about a half of the statistical stations. There is notable temperature effect in the middle and northern Tibetan Plateau and its adjacent Central Asia to the north of the Tanggula Mountains. Because vapor directly originates from low-latitude oceans, the relative heavy ( 18O with small variation characterizes the rainfall in South Asia. A sharp depletion of the stable isotopic compositions in precipitation takes place from Kyangjin on the southern slope of the Himalayas to the Tanggula Mountains in the middle plateau. From the Tanggula Mountains to the northern Tibetan Plateau, the ( 18O in precipitation increases with increasing latitude.

  15. Permanent human occupation of the central Tibetan Plateau in the early Holocene.

    Science.gov (United States)

    Meyer, M C; Aldenderfer, M S; Wang, Z; Hoffmann, D L; Dahl, J A; Degering, D; Haas, W R; Schlütz, F

    2017-01-06

    Current models of the peopling of the higher-elevation zones of the Tibetan Plateau postulate that permanent occupation could only have been facilitated by an agricultural lifeway at ~3.6 thousand calibrated carbon-14 years before present. Here we report a reanalysis of the chronology of the Chusang site, located on the central Tibetan Plateau at an elevation of ~4270 meters above sea level. The minimum age of the site is fixed at ~7.4 thousand years (thorium-230/uranium dating), with a maximum age between ~8.20 and 12.67 thousand calibrated carbon-14 years before present (carbon-14 assays). Travel cost modeling and archaeological data suggest that the site was part of an annual, permanent, preagricultural occupation of the central plateau. These findings challenge current models of the occupation of the Tibetan Plateau. Copyright © 2017, American Association for the Advancement of Science.

  16. Ozark Plateau National Wildlife Refuge: Comprehensive Conservation Plan and Environmental Assessment

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on Ozark Plateau National Wildlife Refuge for the next 15 years. This plan outlines the...

  17. Geologic structural features within the Kaiparowits Plateau study area, southern Utah (kaistrcg)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This is a line coverage of the geologic structural features within the Kaiparowits Plateau. Structural features include synclines, anticlines, folds and faults; and...

  18. Boundary delimiting the area within which coal resources were calculated, southern Wasatch Plateau (wsbndg)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This is a shapefile and coverage that outlines the area underlain by coals in the lower Blackhawk Formation, southern Wasatch Plateau coal assessment area. The...

  19. Evolution of the Southern Guinea Plateau: Implications on Guinea-Demerara Plateau formation using insights from seismic, subsidence, and gravity data

    Science.gov (United States)

    Olyphant, Jared R.; Johnson, Roy A.; Hughes, Amanda N.

    2017-10-01

    The Guinea Plateau (offshore Guinea) and its conjugate, the Demerara Plateau (offshore French Guiana), comprise two of the most prominent passive continental margins in the Atlantic Ocean. The conjugate plateaus formed as a result of two periods of rifting, the Jurassic opening of the Central Atlantic Ocean and the northward-propagating Cretaceous opening of the Southern Atlantic Ocean. Although several studies are published on the Demerara Plateau that explain the evolution of its multi-rift history and the effect of rifting on its distinct geometry, the Guinea Plateau, and in particular its south-eastern margin, remain relatively unexplored in the literature. Here we present interpretations of the structure and evolution of the Guinea Plateau using recent 2-D and 3-D seismic-reflection data collected at the intersection of the southern and eastern margins. We substantiate our study with calculated subsidence curves at four locations along the southern margin, as well as two 2-D gravity forward models along regional seismic-reflection profiles to estimate stretching factors (β) and crustal thicknesses. We combine our results with previous studies concerning the south-western Guinea margin, and compare them to published interpretations regarding the conjugate margins of the Demerara Plateau. The resolved amounts of rift-related volcanism, listric-style normal faults, and moderate stretching factors suggest that a component of upper-crustal asymmetry (simple shear) and depth-dependent stretching may have persisted at the Demerara-Guinea conjugate margins during Cretaceous rifting of the equatorial segment of the Southern Atlantic Ocean.

  20. The Quaternary Pan-lake (Overflow) Period and Paleoclimate on the Qinghai-Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    ZHENG Mianping; YUAN Heran; ZHAO Xitao; LIU Xifang

    2005-01-01

    Lake geomorphology and high-level lacustrine deposits since the mid-late Pleistocene are well preserved in lakes of the Qinghai-Tibet Plateau. According to geological surveys of 17 lake districts in different locations of the plateau,combined with interpretations of satellite images and topographic maps, the authors studied the timing of formation and scopes of the pan-lake areas of the plateau and their paleoclimate. The latest two high lake levels (overflow surfaces) on the Qinghai-Tibet Plateau in the Quaternary occurred at ~40 to 30/35 ka and ~65 to 53 ka respectively. In these time intervals, the plateau was covered by huge interconnected pan-lake systems with a total area of ~36 km2 and a total volume of lake water of >530 million km2, which are about 38 times and 659 times larger than those of the modem lakes respectively. Before this pan-lake period in the late Pleistocene, there had been three high lake levels that occurred at ~132-112 ka, 110-95 ka and 91-72/~83-75 ka respectively, suggesting that the late Quaternary climate on the plateau was unstable and changed rapidly. The ~40-30 ka high lake level also appeared in the Tengger desert north of the plateau,suggesting that there existed very strong summer monsoons from South Asia then; the variation in solar radiation with a 20,000 precessional period has special importance for the high-altitude Qinghai-Tibet Plateau in the low-latitude zone of the Earth. Around 30 ka, the pan-lakes at the peripheries of the Qinghai-Tibet Plateau drained out suddenly with rapid uplift of the plateau and cooling. In a short time the huge amount of cold lake water emptied into the Indian Ocean and Western Pacific. The draining event of the pan-lakes brought about the environmental changes of rivers and lakes at peripheries of the plateau.

  1. The Response of Snow on Tibetan Plateau in Winter to Indian Ocean Sea Surface Temperature Anomaly

    Science.gov (United States)

    Jia, Lha; Xiao, Tiangui; Wang, Chao; Du, Jun; Zhou, Xiaoli

    2017-04-01

    By using the daily snow depth and snow cover days data at 100 meteorological stations in Tibetan Plateau during 1979-2013, the methods of EOF, REOF and SVD were used to analyze the distribution characteristic and time series variation of snow in Tibetan Plateau. The coupling relationship between snow in Tibetan Plateau in winter and Indian Ocean sea surface temperature in winter, and the lag response of the snow in Tibetan Plateau in winter to Indian Ocean sea surface temperature were also studied. Main conclusions are as follows: 1.Snow depth and snow cover reaches the maximum value in January and reaches the minimum value in July; accumulated snow depth and snow cover days shows an increasing tendency during 1980s to 1990s and has a decreasing tendency since then. The accumulated snow depth and snow cover days decrease in summer and increase in autumn. 2. There were 4 high-frequency centers of snow cover days and accumulated snow depth: the southern Himalayas area, the area between the Tanggula Mountains and the Nyainqentanglha Mountains, the area around Bayankela Mountains and the area around Qilian Mountains. 3. The first pattern of SVD between snow in Tibetan Plateau in winter and Indian Ocean sea surface temperature in winter has the feature that Indian Ocean sea surface temperature increase in the whole area and snow has an opposite trend in the western and southeastern Plateau and the northern and southern Plateau. The second pattern shows that Indian Ocean sea surface temperature has an opposite trend in the western ocean and the eastern ocean and snow has an opposite trend in the western Plateau and the southeastern Plateau. There is a significant negative correlation between Indian Ocean sea surface temperature in June and July and snow in Tibetan Plateau in winter. Key words: Tibetan Plateau; snow; Indian Ocean; SVD Acknowledgements This study was supported by National Natural Science Foundation of China Fund Project (91337215, 41575066),National Key

  2. Analysis of aerodynamic and thermodynamic parameters on the grassy marshland surface of Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The aerodynamic roughness z0m, the thermodynamic roughness z0h and the excess resistance to heat transfer kB-1 are analyzed with the data obtained from Global Energy and Water Cycle Experiment (GEWEX) Asian Monsoon Experiment on Tibetan Plateau (GAME/Tibet) in the Intensive Observation Period (IOP), 1998. Some new concepts on the aerodynamic and thermodynamic parameters over the grassy marshland surface of the Tibetan Plateau are proposed.

  3. Identifying the source regions of persistent organic pollutants (POPs) in the southern Tibetan Plateau

    Science.gov (United States)

    Gong, P.; Wang, X.; Yao, T.

    2016-12-01

    A worldwide attention focus on the semi-volatilities and long-range atmospheric transport potential of persistent organic pollutants (POPs). Even in the remote regions with less anthropological activities (such as Arctic, Antarctic), POPs are often detected in air and finally are trapped by the surface ground, which made those regions as a "sink" of POPs. The Tibetan Plateau is also a remote region, and it is adjacent to South Asia with huge emission of POPs. The strong monsoon favors to the atmospheric transport of pollutants from South Asia to the Tibetan Plateau. Unlike Arctic and Antarctic, the Tibetan Plateau can become a "secondary source" for some POPs and make them spread globally. By now, some efforts were conducted to report that South Asia is one of the primary source region of POPs in the Tibetan Plateau. In this study, the detailed source regions were identified using 1-year observed atmospheric POPs data in three sites distributing the southern Tibetan Plateau (Lhasa, Lulang, and Lijiang). The highest concentrations of atmospheric POPs in the three sites all occurred in the Monsoon season (June-September), implying that the Indian monsoon may be the driving force of POPs transport to the southern Tibetan Plateau. The relative components of POPs in these sites are similar with those in India, which suggest that South Asia (especially India) might be the main source regions. The results of potential source contribution function (PSCF) further identified that the offshore of Bengal Bay is the most probable emission source region of the POPs invading into the Tibetan Plateau. The mega-cities, such as Kolkata, Bhubaneswar, Chennai, Dhaka, Chittagong, around the Bengal Bay supplied the major contribution of the POPs which transported to the Tibetan Plateau.

  4. Sensitivity of the Colorado Plateau to Change: Climate, Ecosystems, and Society

    OpenAIRE

    Jayne Belnap; David R. Bowling; Susan Schwinning; Ehleringer, James R.

    2008-01-01

    The Colorado Plateau is located in the interior, dry end of two moisture trajectories coming from opposite directions, which have made this region a target for unusual climate fluctuations. A multi-decadal drought event some 850 years ago may have eliminated maize cultivation by the first human settlers of the Colorado Plateau, the Fremont and Anasazi people, and contributed to the abandonment of their settlements. Even today, ranching and farming are vulnerable to drought and struggle to per...

  5. Degenerate Rayleigh-Plateau instability in a magnetically annealed colloidal dispersion

    CERN Document Server

    Swan, James W; First, Eric M

    2013-01-01

    This fluid dynamics video depicts the evolution of a suspension of paramagnetic colloids un- der the influence of a uniform, pulsed magnetic field. At low pulse frequencies, the suspension condenses into columns which decompose via a Rayleigh-Plateau instability. At high pulse fre- quencies, the suspension forms a kinetically arrested, system spanning network. We demonstrate the degeneration of the Rayleigh-Plateau instability with increasing pulse frequency.

  6. Modeling and Mapping Soil Moisture of Plateau Pasture Using RADARSAT-2 Imagery

    OpenAIRE

    Xun Chai; Tingting Zhang; Yun Shao; Huaze Gong; Long Liu; Kaixin Xie

    2015-01-01

    Accurate soil moisture retrieval of a large area in high resolution is significant for plateau pasture. The object of this paper is to investigate the estimation of volumetric soil moisture in vegetated areas of plateau pasture using fully polarimetric C-band RADARSAT-2 SAR (Synthetic Aperture Radar) images. Based on the water cloud model, Chen model, and Dubois model, we proposed two developed algorithms for soil moisture retrieval and validated their performance using experimental data. We ...

  7. Land surface changes enhanced drought over the Loess Plateau

    Science.gov (United States)

    Xu, Xianli; Liu, Meixian

    2017-04-01

    In order to prevent the severe soil-water erosion over the Loess Plateau (LP), the Chinese Government initiated large scale ecological restoration (ER) in the past half century. The ER had successfully reduced soil erosion however also changed the land surface and altered the regional water-energy balance and consequently the dryness/wetness conditions, which in turn affects the vegetation. Knowledge of the impacts of the ER on dryness/wetness conditions is essential for developing future effective ER measures. For this purpose, a new drought index, the standardized wetness index (SWI), was proposed. The SWI can represent the dryness/wetness brought by solely climate change (denoted as SWIf in this case), and the dryness/wetness brought by the joint effects of climate change and land surface change (SWI_m). A total of 13 main catchments were selected to investigate the effects of ER on dryness/wetness conditions during 1961-2009 over LP. Results showed that the overall increasing parameter n (a parameter of the Budyko formulae) could be well explained by the ER measures (R^2=1) in these catchments. The SWIf and SWIm had similar fluctuating features and exhibited downward trends. However, the SWIm had larger negative trends than the SWI_f, implying that ER actions enhanced the drought conditions over the drying LP in the past decades. Therefore, we suggest that the government should manage and maintain the existing achievements but not further expand revegetation because of unintended consequences on drought vulnerability.

  8. Atmospheric particulate mercury in Lhasa city, Tibetan Plateau

    Science.gov (United States)

    Huang, Jie; Kang, Shichang; Guo, Junming; Zhang, Qianggong; Cong, Zhiyuan; Sillanpää, Mika; Zhang, Guoshuai; Sun, Shiwei; Tripathee, Lekhendra

    2016-10-01

    In an effort to understand the biogeochemical cycling and seasonal characteristics of atmospheric Hg, a total of 80 daily sampled total suspended particulates were collected at Lhasa, the largest city of Tibet, from April 2013 to August 2014 for particulate-bound Hg (HgP) analysis. Daily concentrations of atmospheric HgP ranged from 61.2 to 831 pg m-3 with an average of 224 pg m-3, which were unexpectedly comparable to those measured in most of the Chinese metropolises. Both the daily/monthly average HgP concentrations were slightly but not significantly higher during the non-monsoon season than during the monsoon season. Together with the fact that there was lack of significant relationship between HgP concentration and most meteorological parameters, no significant and distinct pattern for the seasonal characteristics of atmospheric HgP could be mainly attributed to the almost equal emission strength of two principal anthropogenic Hg sources (i.e., industrial emission sources during the non-monsoon season, and vehicular traffic and religious sources during the monsoon season). Moreover, the HgP dry deposition rate was estimated to be 35.3 μg m-2 yr-1 by using a theoretical model, which was significantly higher than those Hg wet fluxes. The elevated deposition rate implied that dry deposition may play an important role in the biogeochemical Hg cycling over the Tibetan Plateau.

  9. Butterflies of the Bodoquena Plateau in Brazil (Lepidoptera, Papilionoidea)

    Science.gov (United States)

    de Souza, Paulo Ricardo Barbosa; Guillermo-Ferreira, Rhainer

    2015-01-01

    Abstract Butterflies and moths are found in all terrestrial environments and require efforts for a better understanding of its mega-diversity. These taxa have been the subject of several studies involving phylogeny, ecology and environmental impacts. Nevertheless, several areas in the tropics remain unexplored, resulting in gaps in the taxonomic composition and distribution of butterflies in endemic environments. Therefore, a survey of the butterfly fauna of the Bodoquena Plateau in Brazil was conducted. This area consists of tropical Atlantic Forests, with marginal influences of Savannah, Chaco and Pantanal. Sampling was carried out in 20 locations using Van Someren Rydon traps and insect nets between November 2009 and April 2015. Active collection of individuals was conducted from 9:00 to 17:00h, totaling 240 hours of sampling effort. In total, we registered 768 individuals belonging to 146 species of 98 genera, six families and 18 subfamilies. Nymphalidae was the richest family (84 species), followed by Hesperiidae (22 species), Riodinidae (14 species), Pieridae (12) Papilionidae (11 species) and Lycaenidae (five species). We sampled 239 nymphalids in traps, with 48 species, 30 genera, 15 tribes and five subfamilies. The most common species were Eunica macris (Godart, 1824), Dynamine artemisia (Fabricius, 1793) and Memphis moruus (Fabricius, 1775). Therefore, this study contributes to the knowledge of the Neotropical butterfly diversity and distribution, providing 37 new records and supporting the use of wildlife inventories as important tools for the knowledge of tropical forests biodiversity and conservation. PMID:26798308

  10. Excellent daytime seeing at Dome Fuji on the Antarctic plateau

    CERN Document Server

    Okita, H; Ashley, M C B; Takato, N

    2013-01-01

    Context. Dome Fuji, the second highest region on the Antarctic plateau, is expected to have some of the best astronomical seeing on Earth. However, site testing at Dome Fuji is still in its very early stages. Aims. To investigate the astronomical seeing in the free atmosphere above Dome Fuji, and to determine the height of the surface boundary layer. Methods. A Differential Image Motion Monitor was used to measure the seeing in the visible (472 nm) at a height of 11 m above the snow surface at Dome Fuji during the austral summer of 2012/2013. Results. Seeing below 0.2'' has been observed. The seeing often has a local minimum of ~0.3'' near 18 h local time. Some periods of excellent seeing, 0.3'' or smaller, were also observed, sometimes extending for several hours at local midnight. The median seeing is higher, at 0.52''---this large value is believed to be caused by periods when the telescope was within the turbulent boundary layer. Conclusions. The diurnal variation of the daytime seeing at Dome Fuji is sim...

  11. "Mucientes Chert" in the Northern Iberian Plateau (Spain

    Directory of Open Access Journals (Sweden)

    M. Natividad Fuertes-Prieto

    2014-03-01

    Full Text Available The so-called “Mucientes chert" is a variety that appears in the central area of the Iberian North Plateau, in theDueroBasin. It is widely known in the geological and archaeological literature and its use for knapping was especially important in Prehistory. From a macroscopic point of view it is a nodular chert, with white and very porous cortex, and brown to blackish or beige colour in the inner part.In this work we carried out a more accurate petrographic, mineralogical and chemical characterization of this lithology using SEM, XRD and XRF techniques in samples coming from “Las Canteras” (Mucientes village, a chert outcrop of the “Cuestas” Unit (Vallesian-Aragonian, Miocene Age. Also, we have made a review of its geological occurrence and archaeological distribution areas.  It is intended to sketch the delimitation of the geographical area of occurrence taking into account the geological and archaeological references. 

  12. On the inward drift of runaway electrons in plateau regime

    CERN Document Server

    Hu, Di

    2016-01-01

    The well observed inward drift of current carrying runaway electrons during runaway plateau regime after disruption is studied by considering the phase space dynamic of runaways in a large aspect ratio toroidal system. We consider the case where the toroidal field is unperturbed and the toroidal symmetry of the system is preserved. The invariance of canonical angular momentum in such system requires runaways to drift horizontally in configuration space for any given change in momentum space. The dynamic of this drift can be obtained by taking the variation of canonical angular momentum. It is then found that runaway electrons will always drift inward as long as they are decelerating. This drift motion is essentially non-linear, since the current is carried by runaways themselves, and any runaway drift relative to the magnetic axis will cause further displacement of the axis itself. A simplified analytical model is constructed to describe such inward drift both in ideal wall case and no wall case, and the runa...

  13. Seismicity and average velocities beneath the Argentine Puna Plateau

    Science.gov (United States)

    Schurr, B.; Asch, G.; Rietbrock, A.; Kind, R.; Pardo, M.; Heit, B.; Monfret, T.

    A network of 60 seismographs was deployed across the Andes at ∼23.5°S. The array was centered in the backarc, atop the Puna high plateau in NW Argentina. P and S arrival times of 426 intermediate depth earthquakes were inverted for 1-D velocity structure and hypocentral coordinates. Average velocities and υp/υs in the crust are low. Average mantle velocities are high but difficult to interpret because of the presence of a fast velocity slab at depth. Although the hypocenters sharply define a 35° dipping Benioff zone, seismicity in the slab is not continuous. The spatial clustering of earthquakes is thought to reflect inherited heterogeneties of the subducted oceanic lithosphere. Additionally, 57 crustal earthquakes were located. Seismicity concentrates in the fold and thrust belt of the foreland and Eastern Cordillera, and along and south of the El Toro-Olacapato-Calama Lineament (TOCL). Focal mechanisms of two earthquakes at this structure exhibit left lateral strike-slip mechanisms similar to the suggested kinematics of the TOCL. We believe that the Puna north of the TOCL behaves like a rigid block with little internal deformation, whereas the area south of the TOCL is weaker and currently deforming.

  14. Instability Paths in the Kirchhoff-Plateau Problem

    Science.gov (United States)

    Giusteri, Giulio G.; Franceschini, Paolo; Fried, Eliot

    2016-08-01

    The Kirchhoff-Plateau problem concerns the equilibrium shapes of a system in which a flexible filament in the form of a closed loop is spanned by a soap film, with the filament being modeled as a Kirchhoff rod and the action of the spanning surface being solely due to surface tension. Adopting a variational approach, we define an energy associated with shape deformations of the system and then derive general equilibrium and (linear) stability conditions by considering the first and second variations of the energy functional. We analyze in detail the transition to instability of flat circular configurations, which are ground states for the system in the absence of surface tension, when the latter is progressively increased. Such a theoretical study is particularly useful here, since the many different perturbations that can lead to instability make it challenging to perform an exhaustive experimental investigation. We generalize previous results, since we allow the filament to possess a curved intrinsic shape and also to display anisotropic flexural properties (as happens when the cross section of the filament is noncircular). This is accomplished by using a rod energy which is familiar from the modeling of DNA filaments. We find that the presence of intrinsic curvature is necessary to obtain a first buckling mode which is not purely tangent to the spanning surface. We also elucidate the role of twisting buckling modes, which become relevant in the presence of flexural anisotropy.

  15. Butterflies of the Bodoquena Plateau in Brazil (Lepidoptera, Papilionoidea).

    Science.gov (United States)

    de Souza, Paulo Ricardo Barbosa; Guillermo-Ferreira, Rhainer

    2015-01-01

    Butterflies and moths are found in all terrestrial environments and require efforts for a better understanding of its mega-diversity. These taxa have been the subject of several studies involving phylogeny, ecology and environmental impacts. Nevertheless, several areas in the tropics remain unexplored, resulting in gaps in the taxonomic composition and distribution of butterflies in endemic environments. Therefore, a survey of the butterfly fauna of the Bodoquena Plateau in Brazil was conducted. This area consists of tropical Atlantic Forests, with marginal influences of Savannah, Chaco and Pantanal. Sampling was carried out in 20 locations using Van Someren Rydon traps and insect nets between November 2009 and April 2015. Active collection of individuals was conducted from 9:00 to 17:00h, totaling 240 hours of sampling effort. In total, we registered 768 individuals belonging to 146 species of 98 genera, six families and 18 subfamilies. Nymphalidae was the richest family (84 species), followed by Hesperiidae (22 species), Riodinidae (14 species), Pieridae (12) Papilionidae (11 species) and Lycaenidae (five species). We sampled 239 nymphalids in traps, with 48 species, 30 genera, 15 tribes and five subfamilies. The most common species were Eunica macris (Godart, 1824), Dynamine artemisia (Fabricius, 1793) and Memphis moruus (Fabricius, 1775). Therefore, this study contributes to the knowledge of the Neotropical butterfly diversity and distribution, providing 37 new records and supporting the use of wildlife inventories as important tools for the knowledge of tropical forests biodiversity and conservation.

  16. [Clinical practice guideline on closed tibial plateau fractures in adulthood].

    Science.gov (United States)

    Ocegueda-Sosa, Miguel Ángel; Valenzuela-Flores, Adriana Abigail; Aldaco-García, Víctor Daniel; Flores-Aguilar, Sergio; Manilla-Lezama, Nicolás; Pérez-Hernández, Jorge

    2013-01-01

    Closed tibiae plateau fractures are common injuries in the emergency room. The optimal treatment is not well defined or established. For this reason, there are several surgical management options: open reduction and internal fixation, closed reduction and percutaneous synthesis, external fixation, and even conservative treatment for this kind of fracture. The mechanism of production of this fracture is through large varus or valgus deformation to which is added a factor of axial load. The trauma may be direct or indirect. The degree of displacement, fragmentation and involvement of soft tissues like ligaments, menisci, vascular and nerve structures are determined by the magnitude of the force exerted. Any intra-articular fracture treatment can lead to an erroneous instability, deformity and limitation of motion with subsequent arthritic changes, leading to joint incongruity, limiting activity and significantly altering the quality of life. Open reduction and internal fixation with anatomic restitution is the method used in this type of fracture. However, the results of numerous publications can be questioned due to the inclusion in the same study of fractures treated with very different methods.

  17. Does summer precipitation trend of Tibetan Plateau depend on elevation?

    Science.gov (United States)

    Li, X.; Wang, L.; Guo, X.; Chen, D.

    2016-12-01

    The Tibetan Plateau (TP) experienced a rapid warming and wetting in recent decades. The elevation dependence of warming rate has been established, while the question of trend in precipitation against the elevation gradient remains open. By using the in-situ data of precipitation, air temperature, and surface specific humidity from 91 stations on the TP, this study investigated how the trends in summer precipitation varied along the elevation gradient on the TP during 1970-2014. The major findings are as follows. (1) The trends in summer precipitation from 1970-2014 displayed an increasing tendency with the increased elevation at a rate of 0.83 % decade-1 per meter, and the rate for 1991-2014 (2.23 % decade-1 per meter) is even greater. (2) The temporal trends in surface air temperature, surface specific humidity (surface water vapor) from in-situ observations and total column of water vapor from JRA-55 reanalysis data over most stations consistently display similar elevation dependence, which provides a plausible explanation for the elevation dependence of the summer precipitation trends based on the Clausius-Clapeyron relationship.

  18. An ecosystem approach to combat desertification on the Colorado Plateau.

    Science.gov (United States)

    Clements, Amanda

    2004-12-01

    Desertification of shrub and grassland into pinyon-juniper woodland is occurring over much of the Colorado Plateau in the southwestern United States. As trees invade, they out-compete shrubs and grasses, increasing erosion rates and reducing infiltration of moisture into the soil. This has caused habitat problems for wildlife, and reduced forage for livestock. These impacts also affect the human communities that rely on ranching and tourism related to hunting. Past land use and management practices including heavy livestock grazing, fire suppression and introduction of exotic annual plants are believed to have led to current conditions. The Montrose office of the Bureau of Land Management has implemented an ecosystem-based program to reverse the desertification process on public land. The program is centered on detailed landscape objectives describing the desired vegetation mosaic on 360,000 ha of public land. The objectives outline proportions of plant seral stages and arrays of patch sizes for each planning unit. These objectives are based on priority management issues and the need to replicate a natural vegetation mosaic. Where the existing mosaic does not meet objectives, mechanical vegetation treatments and prescribed fire are used to create early and mid-seral patches on the ground. This restored vegetation pattern and type should be sustained over time through a natural fire regime and improved livestock management. Because many uncertainties exist, an adaptive management process is being used that allows mosaic objectives to be changed or processes modified where monitoring or scientific research indicate a need.

  19. Radiation-hydrodynamical modelling of underluminous type II plateau Supernovae

    CERN Document Server

    Pumo, M L; Spiro, S; Pastorello, A; Benetti, S; Cappellaro, E; Manicò, G; Turatto, M

    2016-01-01

    With the aim of improving our knowledge about the nature of the progenitors of low-luminosity Type II plateau supernovae (LL SNe IIP), we made radiation-hydrodynamical models of the well-sampled LL SNe IIP 2003Z, 2008bk and 2009md. For these three SNe we infer explosion energies of $0.16$-$0.18$ foe, radii at explosion of $1.8$-$3.5 \\times 10^{13}$ cm, and ejected masses of $10$-$11.3$\\Msun. The estimated progenitor mass on the main sequence is in the range $\\sim 13.2$-$15.1$\\Msun\\, for SN 2003Z and $\\sim 11.4$-$12.9$\\Msun\\, for SNe 2008bk and 2009md, in agreement with estimates from observations of the progenitors. These results together with those for other LL SNe IIP modelled in the same way, enable us also to conduct a comparative study on this SN sub-group. The results suggest that: a) the progenitors of faint SNe IIP are slightly less massive and have less energetic explosions than those of intermediate-luminosity SNe IIP, b) both faint and intermediate-luminosity SNe IIP originate from low-energy explo...

  20. Magnetotelluric data, Taos Plateau Volcanic Field, New Mexico

    Science.gov (United States)

    Ailes, Chad E.; Rodriguez, Brian D.

    2010-01-01

    The population of the San Luis Basin region of northern New Mexico is growing. Water shortfalls could have serious consequences. Future growth and land management in the region depend on accurate assessment and protection of the region's groundwater resources. An important issue in managing the groundwater resources is a better understanding of the hydrogeology of the Santa Fe Group and the nature of the sedimentary deposits that fill the Rio Grande rift, which contain the principal groundwater aquifers. The shallow unconfined aquifer and the deeper confined Santa Fe Group aquifer in the San Luis Basin are the main sources of municipal water for the region. The U.S. Geological Survey (USGS) is conducting a series of multidisciplinary studies of the San Luis Basin. Detailed geologic mapping, high-resolution airborne magnetic surveys, gravity surveys, an electromagnetic survey called magnetotellurics (MT), and hydrologic and lithologic data are being used to better understand the aquifers. This report describes a regional east-west MT sounding profile acquired in late July 2009 across the Taos Plateau Volcanic Field where drillhole data are sparse. Resistivity modeling of the MT data can be used to help map changes in electrical resistivity with depths that are related to differences in rock types. These various rock types help control the properties of aquifers. The purpose of this report is to release the MT sounding data collected along the east-west profile. No interpretation of the data is included.

  1. Local adaptation of Gymnocypris przewalskii (Cyprinidae) on the Tibetan Plateau.

    Science.gov (United States)

    Zhang, Renyi; Ludwig, Arne; Zhang, Cunfang; Tong, Chao; Li, Guogang; Tang, Yongtao; Peng, Zuogang; Zhao, Kai

    2015-05-06

    Divergent selection among environments affects species distributions and can lead to speciation. In this article, we investigated the transcriptomes of two ecotypes of scaleless carp (Gymnocypris przewalskii przewalskii and G. p. ganzihonensis) from the Tibetan Plateau. We used a transcriptome sequencing approach to screen approximately 250,000 expressed sequence tags (ESTs) from the gill and kidney tissues of twelve individuals from the Ganzi River and Lake Qinghai to understand how this freshwater fish has adapted to an ecological niche shift from saline to freshwater. We identified 9,429 loci in the gill transcriptome and 12,034 loci in the kidney transcriptome with significant differences in their expression, of which 242 protein-coding genes exhibited strong positive selection (Ka/Ks > 1). Many of the genes are involved in ion channel functions (e.g., Ca(2+)-binding proteins), immune responses (e.g., nephrosin) or cellular water absorption functions (e.g., aquaporins). These results have potentially broad importance in understanding shifts from saline to freshwater habitats. Furthermore, this study provides the first transcriptome of G. przewalskii, which will facilitate future ecological genomics studies and aid in the identification of genes underlying adaptation and incipient ecological speciation.

  2. Mutual influence between human activities and climate change in the Tibetan Plateau during recent years

    Science.gov (United States)

    Du, Mingyuan; Kawashima, Shigeto; Yonemura, Seiichiro; Zhang, Xianzhou; Chen, Shenbin

    2004-07-01

    It is well known that there is a vast expanse of grassland on the Tibetan Plateau, China. It is suggested that a major climatic factor limiting production of the grassland ecosystem is the low thermo-conditions on the Tibetan Plateau. An increase in temperature may therefore increase the productivity of grasslands on the Plateau. Monthly mean temperature and monthly precipitation data for recent years on the Tibetan Plateau were analyzed. It is clear that the increase in air temperature on the Plateau is greater than that in the whole China and East Asia. On the other hand, statistics show that the production of livestock or meat in the Tibetan Plateau has increased by one to three times since 1978, which means that there should be an equivalent increase in the consumption of plant biomass from the grassland. How is the "increased biomass" related to human activities and climate changes? This paper tries to clarify the relationship between human activities and climate change and to propose a possible answer by laying emphasis on the importance of grassland protection and CO 2 flux monitoring. It is suggested that there is a positive feedback in which degradation of grassland by overgrazing will increase potential evapotranspiration level thereby promoting the climate warming and the degradation process. This feedback should be considered seriously in the future.

  3. Triple plating of tibia in a complex bicondylar tibial plateau fracture

    Institute of Scientific and Technical Information of China (English)

    Atin Jaiswal; Naiman Deepak Kachchhap; Yashwant S Tanwar; Birendra Kumar; Sachin K Yadav

    2014-01-01

    High-energy tibial plateau fracture poses a significant challenge and difficulty for orthopaedic surgeons.Fracture of tibial plateau involves major weight bearing joint and may alter knee kinematics.Anatomic reconstruction of the proximal tibial articular surfaces,restoration of the limb axis (limb alignment) and stable fixation permitting early joint motion are the goals of the treatment.In cases of complex bicondylar tibial plateau fractures,isolated lateral plating is frequently associated with varus malalignment and better results have been obtained with bilateral plating through dual incisions.However sometimes a complex type of bicondylar tibial plateau fractures is encountered in which medial plateau has a biplaner fracture in posterior coronal plane as well as sagittal plane.In such fractures it is imperative to fix the medial plateau with buttressing in both planes.One such fracture pattern of the proximal tibia managed by triple plating through dual posteromedial and anterolateral incisions is discussed in this case report with emphasis on mechanisms of this type of injury,surgical approach and management.

  4. Gait characteristics and quality of life perception of patients following tibial plateau fracture.

    Science.gov (United States)

    Warschawski, Yaniv; Elbaz, Avi; Segal, Ganit; Norman, Doron; Haim, Amir; Jacov, Elis; Grundshtein, Alon; Steinberg, Ely

    2015-11-01

    The purpose of the current study was to evaluate the long-term functional outcome as measured by gait patterns and quality of life assessment of patients with high-energy tibial plateau fracture compared to matched controls. Thirty-eight patients were evaluated in a case-controlled comparison. Twenty-two patients with tibial plateau fracture were evaluated after 3.1 (1.63) years (sd) from injury. Patients underwent a computerized spatiotemporal gait test and completed the SF-12 health survey. 16 healthy subjects, matched for age and gender served as a control group. The main outcome measures for this study were spatiotemporal gait characteristics, physical quality of life and mental quality of life. Significant differences were found in all gait parameters between patients with tibial plateau fracture and healthy controls. Patients with tibial plateau fracture walked slower by 18% compared to the control group (p life exist in patients following tibial plateau fracture. Patients following tibial plateau fracture present altered spatiotemporal gait patterns compared to healthy controls, as well as self-reported quality of life.

  5. Azimuthal anisotropy of Rayleigh waves beneath the Tibetan Plateau and adjacent areas

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The crustal and upper mantle azimuthal anisotropy of the Tibetan Plateau and adjacent areas was studied by Rayleigh wave tomography. We collected sufficient broadband digital seismograms trav-ersing the Tibetan Plateau and adjacent areas from available stations, including especially some data from the temporary stations newly deployed in Yunnan, eastern Tibet, and western Sichuan. They made an adequate path coverage in most regions to achieve a reasonable resolution for the inversion. The model resolution tests show that the anisotropic features of scope greater than 400 km and strength greater than 2% are reliable. The azimuthal anisotropy pattern inside the Tibetan Plateau was similar to the characteristic of tectonic partition. The crustal anisotropy strength is greater than 2% in most re-gions of East Tibet, and the anisotropy shows clockwise rotation surrounding the eastern Himalayan syntaxis. Vertically, the anisotropy direction indicates a coherent pattern within the upper crust, lower crust, and lithosphere mantle of the Tibetan Plateau, which also is consistent with GPS velocity field and SKS fast polarization directions. The result supports that the crust-mantle deformation beneath the Tibetan Plateau is vertically coherent. The anisotropy strength of crust and lithospheric upper mantle in Yunnan outside the Tibetan Plateau is lower than 2%, so SKS splitting from core-mantle boundary to station should largely be attributed to the anisotropy of asthenosphere.

  6. Azimuthal anisotropy of Rayleigh waves beneath the Tibetan Plateau and adjacent areas

    Institute of Scientific and Technical Information of China (English)

    SU Wei; WANG ChunYong; HUANG ZhongXian

    2008-01-01

    The crustal and upper mantle azimuthal anisotropy of the Tibetan Plateau and adjacent areas was studied by Rayleigh wave tomography. We collected sufficient broadband digital seismograms traversing the Tibetan Plateau and adjacent areas from available stations, including especially some data from the temporary stations newly deployed in Yunnan, eastern Tibet, and western Sichuan. They made an adequate path coverage in most regions to achieve a reasonable resolution for the inversion. The model resolution tests show that the anisotropic features of scope greater than 400 km and strength greater than 2% are reliable. The azimuthal anisotropy pattern inside the Tibetan Plateau was similar to the characteristic of tectonic partition. The crustal anisotropy strength is greater than 2% in most regions of East Tibet, and the anisotropy shows clockwise rotation surrounding the eastern Himalayan syntaxis. Vertically, the anisotropy direction indicates a coherent pattern within the upper crust, lower crust, and lithosphere mantle of the Tibetan Plateau, which also is consistent with GPS velocity field and SKS fast polarization directions. The result supports that the crust-mantle deformation beneath the Tibetan Plateau is vertically coherent. The anisotropy strength of crust and lithospheric upper mantle in Yunnan outside the Tibetan Plateau is lower than 2%, so SKS splitting from core-mantle boundary to station should largely be attributed to the anisotropy of asthenosphere.

  7. Ice core precipitation record in central Tibetan plateau since AD 1600

    Directory of Open Access Journals (Sweden)

    T. Yao

    2008-02-01

    Full Text Available Lack of reliable long-term precipitation record from northern Tibetan Plateau has constrained the understanding of precipitation variation in this region. An ice core drilled from the Puruogangri Ice Field on central Tibetan Plateau in the year 2000 helped reveal the precipitation variations since AD 1600. Analysis of the annual accumulation data presented precipitation changes from AD 1600, indicative of wet and dry periods in the past 400 year in the central Tibetan Plateau. Accordingly, the 18th and 20th centuries experienced high precipitation period, whilst the 19th century experienced low precipitation period. Such a feature was consistent with precipitation recorded in ice cores from Dunde and Guliya Glaciers, northern Tibetan Plateau. Besides, the results also pointed to consistency in precipitation-temperature correlation on the northern Tibetan Plateau, in a way that temperature and precipitation were positively correlated. But this feature was contrary to the relationship revealed from Dasuopu ice cores, southern Tibetan Plateau, where temperature and precipitation were negatively correlated. The north-south contrast in precipitation amount and its relationship with temperature may shed light on the reconstruction of Asian monsoon since AD 1600.

  8. Vegetation greenness trend (2000 to 2009) and the climate controls in the Qinghai-Tibetan Plateau

    Science.gov (United States)

    Zhang, Li; Guo, Huadong; Ji, Lei; Lei, Liping; Wang, Cuizhen; Yan, Dongmei; Li, Bin; Li, Jing

    2013-01-01

    The Qinghai-Tibetan Plateau has been experiencing a distinct warming trend, and climate warming has a direct and quick impact on the alpine grassland ecosystem. We detected the greenness trend of the grasslands in the plateau using Moderate Resolution Imaging Spectroradiometer data from 2000 to 2009. Weather station data were used to explore the climatic drivers for vegetation greenness variations. The results demonstrated that the region-wide averaged normalized difference vegetation index (NDVI) increased at a rate of 0.036  yr−1. Approximately 20% of the vegetation areas, which were primarily located in the northeastern plateau, exhibited significant NDVI increase trend (p-value NDVI and precipitation, especially in the northeastern plateau, suggested that precipitation was a favorable factor for the grassland NDVI. Negative correlations between NDVI and temperature, especially in the southern plateau, indicated that higher temperature adversely affected the grassland growth. Although a warming climate was expected to be beneficial to the vegetation growth in cold regions, the grasslands in the central and southwestern plateau showed a decrease in trends influenced by increased temperature coupled with decreased precipitation.

  9. Imprint of a dissolved cobalt basaltic source on the Kerguelen Plateau

    Directory of Open Access Journals (Sweden)

    J. Bown

    2012-06-01

    Full Text Available Processes of cobalt (Co entrainment from shelf sediments over the Kerguelen Plateau were studied during the KEOPS (Kerguelen Ocean Plateau compared Study in order to explain the exceptionally high dissolved cobalt concentrations that have been measured in the surface waters above the Kerguelen Plateau, and in intermediate and deep waters above its eastern slope. Lateral advection and dissolution of Co contained in basalt sediments around Heard Island, a main source of lithogenic Co in the study area, were shown to imprint the process of surface enrichment over the plateau. Dissolved Co enrichment was strongest at the intercept of the eastern slope with intermediate and deep waters, probably due to more efficient mobilisation of the sediments in the slope current, in addition to advection of Co-enriched and low oxygenated ocean water-masses.

    In surface waters, strong sedimentary Co inputs were estimated to be much higher than biological Co uptake in phytoplankton blooms, underlining the potential role of cobalt as lithogenic tracer. Based on a simple, steady state balance equation of the external input of dissolved iron over the plateau, the fertilization of iron inferred by using Co as a tracer of basalt sources is estimated to be 28 × 102 ± 21 × 102 ton yr−1 in surface waters of the Kerguelen Plateau. This estimate is consistent with preceding ones and the required iron supply matching the phytoplankton demand.

  10. An Innovative Intra-articular Osteotomy in the Treatment of Posterolateral Tibial Plateau Fracture Malunion.

    Science.gov (United States)

    Wang, Yukai; Luo, Congfeng; Hu, Chengfang; Sun, Hui; Zhan, Yu

    2016-07-13

    Posterolateral tibial plateau fractures are not uncommon and the diagnosis can be easily missed. The treatment is technically demanding, which can easily lead to malunion of the posterolateral tibial plateau fracture. Here, we describe an innovative intra-articular osteotomy for the treatment of posterolateral tibial plateau fracture malunion. From 2010 through 2012, 13 patients with a posterolateral tibial plateau fracture malunion were treated in our trauma center. The patients were referred because of instability or knee pain. The instability was confirmed by physical examinations preoperatively. The depression malunion and lower limb alignment were evaluated on X-rays and computed tomography scans. All posterolateral tibial plateau fracture malunions were treated with an innovative intra-articular osteotomy via an extended anterolateral approach. The mean follow-up was 19.6 months (range, 14-28 months). The posterolateral osteotomy healed at an average of 15.1 weeks. The depression malunion was corrected in all patients, which was from 15.4 mm preoperatively to 3.3 mm at 12 months postoperatively. The average Lysholm, Knee Society Score, and visual analog scale scores were 91.7, 92.5, and 0.5, respectively. No loss of reduction, nonunion, or wound infection was observed. An innovative intra-articular osteotomy via an extended anterolateral approach is an effective treatment for posterolateral tibial plateau fracture malunion. The treatment achieved satisfactory functional results and knee stability restoration.

  11. Magnetostratigraphy of Late Cenozoic fossil mammals in the northeastern margin of the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A number of fossil mammals have been found in the very thick Cenozoic stratigraphy of the Guide Basin in the northeastern margin of the Tibetan Plateau. Some of these are of great significance in mammal evolution and stratigraphic correlation on and around the Tibetan Plateau and North China. However, the chronology of these mammals is poorly constrained. Dating of the mammals will not only place precise age constraints on the mammals, but also provide much information on the related stratigraphy that records the uplift process of the Tibetan Plateau. Detailed paleomagnetism of the upper part of the Cenozoic stratigraphy at He'erjia and Lajigai north of Guide County has revealed magnetic chrons that can be correlated to Gauss and 3An chrons, determining the section spanning about 3.1-6.5 Ma and the first, second and third layers of fossil mammals at about 5.25, 5.1 and 4.4 Ma, respectively. Ages of the significant genus Gazella kueitensis and the Chinese elephant Anancus sinensis are firstly constrained at about 5.25 MaBP and 4.4 Ma, respectively. The mammalian evolution and the associated increase in coarse sediments and sedimentation rate may suggest that the northeastern Tibetan Plateau was uplifted rapidly at that time, and the eastern Tibetan Plateau with its neighboring regions was not high enough to stop mammal exchange between the northern and southern sides of the Tibetan Plateau.

  12. Long-term exhumation history of the Inner Mongolian Plateau constrained by apatite fission track analysis

    Science.gov (United States)

    Li, Ke; Jolivet, Marc; Zhang, Zhicheng; Li, Jianfeng; Tang, Wenhao

    2016-01-01

    The Inner Mongolian Plateau, along the southeastern flank of the wider Mongolian Plateau, is a vast undulating surface ranging in elevation between 900 and 1500 m above sea level. The peculiar topography of this area is assumed to be closely related to its complex tectono-thermal evolution since Late Paleozoic. The lithospheric structure of the Plateau includes three continental blocks: the Mandula and the Bart Obo blocks form the southern margin of the Central Asian Orogenic Belt in that area, and to the south, the Plateau includes the northern margin of the North China Craton. Apatite fission track (AFT) ages and track length distributions from 13 basement outcrops situated in the main tectonic blocks forming the Inner Mongolian Plateau were determined in order to reconstruct its denudation history. The thermal histories inferred from these data imply multi-phased, differential exhumation/burying processes from the Late Paleozoic to the Early Cretaceous. This complex thermal history is largely related to the Early/Middle Triassic closure of the Paleo-Asian Ocean, the Jurassic closure of the Mongol-Okhotsk Ocean, and the Early Cretaceous orogenic collapse of the Mongol-Okhotsk belt. Finally, since Late Cretaceous, no further major tectonic movement occurred and the Inner Mongolian Plateau has been largely peneplained.

  13. Slow steady exhumation of the high elevation Deosai Plateau (Northern Pakistan Himalaya) since 40 Ma

    Science.gov (United States)

    van Melle, J.; van der Beek, P.; Guillot, S.; Pecher, A.; Latif, M.

    2007-12-01

    Mountain ranges of the north-western Himalaya in Pakistan show strongly contrasting relief, opposing steep, deeply incised topography with extremely high peaks such as the Karakorum Range and Nanga Parbat Haramosh Massif (NPHM), to high-altitude, low-relief areas such as the Deosai Plateau located between the Karakorum and NPHM and the Tso-Morari Massif in Eastern Ladakh. In contrast, mean elevations of the different mountain ranges are comparable, the Deosai Plateau being on average even slightly higher than the adjacent NPHM. The aim of this study is to quantify the exhumation history the Deosai Plateau, in order to understand how to build such a high-altitude, low-relief plateau and how to preserve it over million-year timescales. Here, we report the first low-temperature thermochronologic data from the Deosai Plateau, to compare its exhumation history to that of the surrounding massifs. Apatite Fission Track (AFT) ages reported in the literature from the NPHM and Karakorum are extremely young (1 km/Ma. In contrast, our AFT ages from the Deosai Plateau are 15-27 Ma; an order of magnitude older than those of the surrounding massifs. Zircon and apatite (U-Th)/He ages (measured at U of Arizona, HeDWaAZ program) range from 23-45 Ma, and 12-15 Ma, respectively. Modeling the combined AFT and He ages requires continuous and very slow long term cooling rates (around 4 ° C/Ma), consistent with an exhumation rate of about 0.15 km/Ma for typical geothermal gradients. Our data thus suggest steady slow unroofing of the Deosai Plateau since at least 40 Ma. A clear link between cooling age patterns and the geomorphology is also evident, with strongly incised, high-relief massifs showing exhumation at rates an order of magnitude faster than the low-relief plateau. AFT and ZFT ages similar to our data have been reported from the Tso Morari massif further east, characterised by similar high-elevation low-relief morphology. These morphologic zones cross the Indus and Shyok Suture

  14. Changes in Cerebral Partial Oxygen Pressure and Cerebrovascular Reactivity During Intracranial Pressure Plateau Waves.

    Science.gov (United States)

    Lang, Erhard W; Kasprowicz, Magdalena; Smielewski, Peter; Pickard, John; Czosnyka, Marek

    2015-08-01

    Plateau waves in intracranial pressure (ICP) are frequently recorded in neuro intensive care and are not yet fully understood. To further investigate this phenomenon, we analyzed partial pressure of cerebral oxygen (pbtO2) and a moving correlation coefficient between ICP and mean arterial blood pressure (ABP), called PRx, along with the cerebral oxygen reactivity index (ORx), which is a moving correlation coefficient between cerebral perfusion pressure (CPP) and pbtO2 in an observational study. We analyzed 55 plateau waves in 20 patients after severe traumatic brain injury. We calculated ABP, ABP pulse amplitude (ampABP), ICP, CPP, pbtO2, heart rate (HR), ICP pulse amplitude (ampICP), PRx, and ORx, before, during, and after each plateau wave. The analysis of variance with Bonferroni post hoc test was used to compare the differences in the variables before, during, and after the plateau wave. We considered all plateau waves, even in the same patient, independent because they are separated by long intervals. We found increases for ICP and ampICP according to our operational definitions for plateau waves. PRx increased significantly (p = 0.00026), CPP (p waves. ABP, ampABP, and HR remained unchanged. PRx during the plateau was higher than before the onset of wave in 40 cases (73 %) with no differences in baseline parameters for those with negative and positive ΔPRx (difference during and after). ORx showed an increase during and a decrease after the plateau waves, however, not statistically significant. PbtO2 overshoot after the wave occurred in 35 times (64 %), the mean difference was 4.9 ± 4.6 Hg (mean ± SD), and we found no difference in baseline parameters between those who overshoot and those who did not overshoot. Arterial blood pressure remains stable in ICP plateau waves, while cerebral autoregulatory indices show distinct changes, which indicate cerebrovascular reactivity impairment at the top of the wave. PbtO2 decreases during the waves and may

  15. The Development in modeling Tibetan Plateau Land/Climate Interaction

    Science.gov (United States)

    Xue, Yongkang; Liu, Ye; li, qian; Maheswor Shrestha, Maheswor; Ma, Hsi-Yen; Cox, Peter; Sun, shufen; Koike, Toshio

    2015-04-01

    Tibetan Plateau (TP) plays an important role in influencing the continental and planetary scale climate, including East Asian and South Asian monsoon, circulation and precipitation over West Pacific and Indian Oceans. The numerical study has identified TP as the area with strongest land/atmosphere interactions over the midlatitude land. The land degradation there has also affected the monsoon precipitation in TP along the monsoon pathway. The water cycle there affects water sources for major Asian river systems, which include the Tarim, Amu Darya, Indus, Ganges, Brahmaputra, Irrawaddy, Salween, Mekong, Yellow, and Yangtze Rivers. Despite the importance of TP land process in the climate system, the TP land surface processes are poorly modeled due to lack of data available for model validation. To better understand, simulate, and project the role of Tibetan Plateau land surface processes, better parameterization of the Tibetan Land surface processes have been developed and evaluated. The recently available field measurement there and satellite observation have greatly helped this development. This paper presents these new developments and preliminary results using the newly developed biophysical/dynamic vegetation model, frozen soil model, and glacier model. In recent CMIP5 simulation, the CMIP5 models with dynamic vegetation model show poor performance in simulating the TP vegetation and climate. To better simulate the TP vegetation condition and its interaction with climate, we have developed biophysical/dynamic vegetation model, the Simplified Simple Biosphere Model version 4/Top-down Representation of Interactive Foliage and Flora Including Dynamics Model (SSiB4/TRIFFID), based on water, carbon, and energy balance. The simulated vegetation variables are updates, driven by carbon assimilation, allocation, and accumulation, as well as competition between plant functional types. The model has been validated with the station data, including those measured over the TP

  16. Topographic Analyses of the Vestalia Terra plateau, Vesta (Invited)

    Science.gov (United States)

    Buczkowski, D.; Wyrick, D. Y.; Williams, D. A.; Preusker, F.; Roatsch, T.; DeSanctis, M. C.; Raymond, C. A.; Russell, C. T.

    2013-12-01

    The identification of Vestalia Terra, a topographically high region of Vesta bound by steep scarps, is itself a direct result of topographic analysis of the asteroid. However, additional analysis of the topography of the plateau has yielded important scientific discoveries. While most equatorial regions on Vesta display numerous wide and flat-floored troughs, Vestalia Terra does not. There are, however, three long pit crater chains on top of the plateau that are roughly aligned with the equatorial flat-floor troughs. Pit crater chains are a type of feature that have been observed on several planetary bodies and have been described as lines of circular to elliptical depressions which lack an elevated rim, ejecta deposits, or lava flows. Individual pits most commonly have a conical shape, sometimes with a flat floor, but in some cases they are elliptical in shape, with the long axis parallel to the chain orientation. Pit craters can in many cases coalesce into linear troughs, but the pits are often bordered by a graben (a down-dropped block bounded by normal faults) even before this coalesence. While pits are generally agreed to have formed by collapse into a subsurface cavity, the exact formation mechanisms hypothesized can vary from planet to planet. However, several researchers have suggested that pit crater chains on small bodies such as Phobos, Eros, Lutetia and Enceladus are formed by the drainage of a loose cover material into subsurface voids formed by dilation of a subsurface normal fault, a method described in extensive detail for pit crater chains on Mars. This formation hypothesis is strengthened by the strong correlation between pit crater chains and fault-bounded graben that has been observed and by the fact that pit chains are often in alignment with a regional fault and fracture system. There are two fundamental controls on the maximum size a pit can attain: the thickness of the overlying regolith and the amount of subsurface accommodation space. The

  17. Integer quantum Hall effect in a triangular-lattice: Disorder effect and scaling behavior of the insulator-plateau transition

    Science.gov (United States)

    Yu, H. L.; Jiang, C.; Zhai, Z. Y.

    2017-01-01

    We investigate numerically the integer quantum Hall effect in a three-band triangular-lattice model. The three bands own the Chern number C=2,-1,-1, respectively. The lowest topological flat band carrying Chern number C=2, which leads to the Hall plateau σH = 2 (e2 / h) . This Hall plateau is sensitive to the disorder scattering and is rapidly destroyed by the weak disorder. Further increasing the strength of disorder, the gap of density of states always disappears before the vanishing of the corresponding Hall plateau. The scaling behavior of quantum phase transition between an insulator and a quantum Hall plateau is studied. We find that the insulator-plateau transition becomes sharper with increasing the size of system. Due to the different of edge states, the critical energy Ec1 gradually shifts to the center of Hall plateau while Ec2 is unaffected with increasing the disorder strength.

  18. Weather and Climate Effects of the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    DUAN Anmin; WU Guoxiong; LIU Yimin; MA Yaoming; ZHAO Ping

    2012-01-01

    Progress in observation experiments and studies concerning the effects of the Tibetan Plateau (TP) on weather and climate during the last 5 years are reviewed.The mesoscale topography over the TP plays an important role in generating and enhancing mesoscale disturbances.These disturbances increase the surface sensible heat (SH) flux over the TP and propagate eastward to enhance convection and precipitation in the valley of Yangtze River.Some new evidence from both observations and numerical simulations shows that the southwesterly flow,which lies on the southeastern flank of the TP,is highly correlated with the SH of the southeastern TP in seasonal and interannual variability.The mechanical and thermal forcing of the TP is an important climatic cause of the spring persistent rains over southeastern China.Moreover,the thermodynamic processes over the TP can influence the atmospheric circulation and climate over North America and Europe by stimulating the large-scale teleconnections such as the Asian-Pacific oscillation and can affect the atmospheric circulation over the southern Indian Ocean.Estimating the trend in the atmospheric heat source over the TP shows that,in contrast to the strong surface and troposphere warming,the SH over the TP has undergone a significant decreasing trend since the mid-1980s.Despite the fact that in situ latent heating presents a weak increasing trend,the springtime atmospheric heat source over the TP is losing its strength.This gives rise to reduced precipitation along the southern and eastern slopes of the TP and to increased rainfall over northeastern India and the Bay of Bengal.

  19. Radiation-hydrodynamical modelling of underluminous Type II plateau supernovae

    Science.gov (United States)

    Pumo, M. L.; Zampieri, L.; Spiro, S.; Pastorello, A.; Benetti, S.; Cappellaro, E.; Manicò, G.; Turatto, M.

    2017-01-01

    With the aim of improving our knowledge about the nature of the progenitors of low-luminosity Type II plateau supernovae (LL SNe IIP), we made radiation-hydrodynamical models of the well-sampled LL SNe IIP 2003Z, 2008bk and 2009md. For these three SNe, we infer explosion energies of 0.16-0.18 foe, radii at explosion of 1.8-3.5 × 1013 cm and ejected masses of 10-11.3 M⊙. The estimated progenitor mass on the main sequence is in the range ˜13.2-15.1 M⊙ for SN 2003Z and ˜11.4-12.9 M⊙ for SNe 2008bk and 2009md, in agreement with estimates from observations of the progenitors. These results together with those for other LL SNe IIP modelled in the same way enable us also to conduct a comparative study on this SN sub-group. The results suggest that (a) the progenitors of faint SNe IIP are slightly less massive and have less energetic explosions than those of intermediate-luminosity SNe IIP; (b) both faint and intermediate-luminosity SNe IIP originate from low-energy explosions of red (or yellow) supergiant stars of low to intermediate mass; (c) some faint objects may also be explained as electron-capture SNe from massive super-asymptotic giant branch stars; and (d) LL SNe IIP form the underluminous tail of the SNe IIP family, where the main parameter `guiding' the distribution seems to be the ratio of the total explosion energy to the ejected mass. Further hydrodynamical studies should be performed and compared to a more extended sample of LL SNe IIP before drawing any conclusion on the relevance of fall-back to this class of events.

  20. Emplacement Scenarios for Vallis Schroteri, Aristarchus Plateau, the Moon

    Science.gov (United States)

    Garry, W. Brent; Bleacher, Jacob E.

    2011-01-01

    The volcanic processes that formed Vallis Schr teri are not well understood. Vallis Schr teri, located on the Aristarchus Plateau, is the largest rille on the Moon, and it displays three key morphologic components: the Cobra Head, the 155-km-long primary rille, and the 240-km-long inner rille. Observations of terrestrial eruptions are applied here to help explain the morphologic relationships observed for Vallis Schr teri. The Cobra Head, a 10-km-wide source vent surrounded by a 35-kmdiameter and 900-m-high low shield, might have been constructed from fl ows, spatter, and pyroclastic deposits erupted during lava fountain events, similar to the early stages of the vent at Pu u O o in Hawaii and the fi nal morphology of Bandera crater, a cinder cone in New Mexico. The vent fed an initial sheet fl ow controlled by preeruption topography. A channel formed within this sheet fl ow was the foundation for the primary rille, which deepened through construction and thermomechanical erosion by lava. The inner rille is confi ned to the fl at fl oor of the primary rille and is characterized by tight gooseneck meanders. This rille crosscuts the distal scarp of the primary rille and extends toward Oceanus Procellarum. This enigmatic relationship can be explained through backup, overfl ow, and diversion of the lava into a new rille that eroded into the margin of the primary rille. Similar backup, overfl ow, and redirection of the lava fl ow were observed during the 1984 Mauna Loa eruption in Hawaii. Analysis of the fi nal morphology of lunar rilles provides key information about lunar volcanic processes and insight into the local stratigraphy.

  1. MANAGING ENGINEERING ACTIVITIES FOR THE PLATEAU REMEDIATION CONTRACT - HANFORD

    Energy Technology Data Exchange (ETDEWEB)

    KRONVALL CM

    2011-01-14

    In 2008, the primary Hanford clean-up contract transitioned to the CH2MHill Plateau Remediation Company (CHPRC). Prior to transition, Engineering resources assigned to remediation/Decontamination and Decommissioning (D&D) activities were a part of a centralized engineering organization and matrixed to the performing projects. Following transition, these resources were reassigned directly to the performing project, with a loose matrix through a smaller Central Engineering (CE) organization. The smaller (10 FTE) central organization has retained responsibility for the overall technical quality of engineering for the CHPRC, but no longer performs staffing and personnel functions. As the organization has matured, there are lessons learned that can be shared with other organizations going through or contemplating performing a similar change. Benefits that have been seen from the CHPRC CE organization structure include the following: (1) Staff are closely aligned with the 'Project/facility' that they are assigned to support; (2) Engineering priorities are managed to be consistent with the 'Project/facility' priorities; (3) Individual Engineering managers are accountable for identifying staffing needs and the filling of staffing positions; (4) Budget priorities are managed within the local organization structure; (5) Rather than being considered a 'functional' organization, engineering is considered a part of a line, direct funded organization; (6) The central engineering organization is able to provide 'overview' activities and maintain independence from the engineering organizations in the field; and (7) The central engineering organization is able to maintain a stable of specialized experts that are able to provide independent reviews of field projects and day-to-day activities.

  2. Deformation and Fluid Flow in the Etendeka Plateau, NW Namibia

    Science.gov (United States)

    Salomon, Eric; Koehn, Daniel; Passchier, Cees; Davis, Jennifer; Salvona, Aron; Chung, Peter

    2014-05-01

    We studied deformation bands in sandstone and breccia veins in overlying basalts of the Etendeka Plateau, NW Namibia, regarding their development and history of fluid flow within. The studied deformation bands can be divided into disaggregation bands and cataclastic bands. The former appear to develop in unsorted sandstone, whereas the latter form in well sorted sandstone. We estimated the porosity of the bands and host rock in thin sections using a simple image analysis software (ImageJ). Results show, that no or only a minor decrease in porosity occur in disaggregation bands, while the porosity in cataclastic bands is decreased by up to 82 % with respect to the host rock. These observations are in agreement with results of existing studies (e.g. Fossen et al., 2007). Hence the cataclastic bands form a seal to fluid flow in the host rock, yet it is observed in outcrops that deformation bands can develop into open fractures which in turn increase the permeability of the rock. Breccia veins in the overlying basalts show intense fracturing where the basalt is locally fractured into elongated chips. Mineral precipitation in these breccia veins indicates a hydrothermal origin of the fluids since the precipitates consist of extremely fine-grained quartz aggregates. Secondary mineralization with large crystals indicates that a long-lived fluid circulation through tubular networks was active at a later stage, which eventually sealed the veins completely. We propose that the Etendeka basalts on top of the sandstone formation produced a localized deformation along deformation bands and heated up fluid below the lavas. At a later stage fluid pressures were either high enough to break through the basalt or fracturing due to ongoing extension produced fluid pathways. References Fossen, H., Schultz, R., Shipton, Z. and Mair, K. (2007). Deformation bands in sandstone: a review. J. Geol. Soc., 164, 755-769.

  3. Seasonal Variation of Climatological Bypassing Flows around the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    LI Qiang; ZHANG Renhe

    2012-01-01

    The present study investigated diagnostically the seasonal variation of the bypassing flows caused by the splitting effect of the Tibetan Plateau (TP).The relationships among the splitting bypassing flows around the TP to precipitation in China,the westerly jet stream,and the thermal status over the TP are revealed.The bypassing flows occur from the 1st to the 22nd pentad and from the 59th to the 73rd pentad,respectively,and they disappear from the 29th to the 58th pentad.They are strongest in winter from the 1st to the 22nd pentad and from the 59th to the 73rd pentad,respectively.During the rebuilding of the bypassing flows from mid-October to mid-February,they are the main cause of precipitation over southeastern China.The enhancement of the bypassing flow intensity in March cau cause the precipitation to increase in the early stage of the persistent spring rain over southeastern China.From winter to summer,the seasonal transition of the bypassing flows in the lower troposphere precedes that of the westerly jet stream axis in the upper troposphere to the west of the TP by ~4 pentads,while from summer to winter lags by ~4 pentads.The seasonal variation of the thermal status over the TP plays an important role in the bypassing flows around the TP.The strengthening of the heating over the TP weakens the bypassing flows,and the increase in cooling over the TP is related to the rebuilding and strengthening of the bypassing flows.

  4. Imprint of a dissolved cobalt basaltic source on the Kerguelen Plateau

    Directory of Open Access Journals (Sweden)

    J. Bown

    2012-12-01

    Full Text Available Processes of cobalt (Co entrainment from shelf sediments over the Kerguelen Plateau were studied during the KEOPS (Kerguelen Ocean Plateau compared Study in order to explain the exceptionally high dissolved cobalt concentrations that have been measured in the surface waters above the Kerguelen Plateau, and in intermediate and deep waters above its eastern slope. Lateral advection and dissolution of Co contained in basalt sediments around Heard Island, a main source of lithogenic Co in the study area, were shown to imprint the process of surface enrichment over the plateau. Dissolved Co enrichment was strongest at the intercept of the eastern slope with intermediate and deep waters, probably due to more efficient mobilisation of the sediments in the slope current, in addition to advection of Co-enriched and low-oxygenated ocean water masses.

    In surface waters, the strong sedimentary Co inputs were estimated to be much higher than biological Co uptake in phytoplankton blooms, underlining the potential use of dissolved cobalt as tracer of the natural iron fertilization above the Kerguelen Plateau. Based on a simple steady-state balance equation of the external input of dissolved iron over the plateau, the fertilization of iron inferred by using dissolved Co as a tracer of basalt sources is estimated to be 28 × 102 ± 21 × 102 t yr−1 in surface waters of the Kerguelen Plateau. This estimate is consistent with preceding ones (Zhang et al., 2008; Chever et al., 2010, and the calculated iron supply matches with the phytoplankton demand (Sarthou et al., 2008.

  5. Continuing Colorado plateau uplift by delamination-style convective lithospheric downwelling.

    Science.gov (United States)

    Levander, A; Schmandt, B; Miller, M S; Liu, K; Karlstrom, K E; Crow, R S; Lee, C-T A; Humphreys, E D

    2011-04-28

    The Colorado plateau is a large, tectonically intact, physiographic province in the southwestern North American Cordillera that stands at ∼1,800-2,000 m elevation and has long been thought to be in isostatic equilibrium. The origin of these high elevations is unclear because unlike the surrounding provinces, which have undergone significant Cretaceous-Palaeogene compressional deformation followed by Neogene extensional deformation, the Colorado plateau is largely internally undeformed. Here we combine new seismic tomography and receiver function images to resolve a vertical high-seismic-velocity anomaly beneath the west-central plateau that extends more than 200 km in depth. The upper surface of this anomaly is seismically defined by a dipping interface extending from the lower crust to depths of 70-90 km. The base of the continental crust above the anomaly has a similar shape, with an elevated Moho. We interpret these seismic structures as a continuing regional, delamination-style foundering of lower crust and continental lithosphere. This implies that Pliocene (2.6-5.3 Myr ago) uplift of the plateau and the magmatism on its margins are intimately tied to continuing deep lithospheric processes. Petrologic and geochemical observations indicate that late Cretaceous-Palaeogene (∼90-40 Myr ago) low-angle subduction hydrated and probably weakened much of the Proterozoic tectospheric mantle beneath the Colorado plateau. We suggest that mid-Cenozoic (∼35-25 Myr ago) to Recent magmatic infiltration subsequently imparted negative compositional buoyancy to the base and sides of the Colorado plateau upper mantle, triggering downwelling. The patterns of magmatic activity suggest that previous such events have progressively removed the Colorado plateau lithosphere inward from its margins, and have driven uplift. Using Grand Canyon incision rates and Pliocene basaltic volcanism patterns, we suggest that this particular event has been active over the past ∼6 Myr.

  6. Late Cretaceous Arc Initiation on the Edge of an Oceanic Plateau (Southern Central America)

    Science.gov (United States)

    Buchs, D. M.; Baumgartner, P. O.; Arculus, R.

    2007-12-01

    The Caribbean Plate comprises one or several late Cretaceous oceanic plateaus imbricated between the Northern and Southern Americas. Uplifted portions of plateau(s) along plate boundaries have been recognized in many sites, including that underlying the south Central American Volcanic Arc. We provide new constraints for the role of the plateau in the evolution of this arc obtained by mapping of the uplifted forearc area between southern Costa Rica and western Panama. An oceanic plateau, accreted seamounts and arc rocks were identified, and a new tectono-stratigraphy defined. The arc basement is composed of a Coniacian oceanic plateau. In the outer margin, late Cretaceous-Eocene accreted seamounts are in contact with the plateau along tectonic mélanges and active faults. Campanian-Maastrichtian primitive arc rocks are found 40-110 km to the trench on the top of -or as dykes within- the plateau. The location of these rocks correlates to previous observations and indicates that the arc front migrated away from the trench during the late Cretaceous, potentially in response to subduction erosion or slab flattening [Lissinna et al., EGU 2006]. The first island arc lavas were deposited under sea level, over a broad area. They were quickly followed by more evolved intrusives and lavas, which were emplaced along a volcanic front during the late Cretaceous-Paleocene. Detrital and volcanic records along the Central American isthmus indicate that a continuous volcanic arc extended between eastern Panama and northern Costa Rica in this time. In southern Costa Rica (Golfito complex) and western Panama (Sona-Azuero-Coiba complex), the oceanic plateau consists mainly of pillowed and massive low Fe (tholeiitic) basalts. These rocks have a highly consistent geochemistry characterized by flat, primitive upper mantle-normalized incompatible element patterns with low Pb and high Nb-Ti contents. Primitive arc igneous samples are low-medium Fe basalts to trachyandesites found as pillow

  7. Studies on the anti-fertility effect of neem oil granules for rodents'ambisexual sterility on Ochotona curzoniae%印楝油两性不育灭鼠粒制剂对高原鼠兔抗生育作用的研究

    Institute of Scientific and Technical Information of China (English)

    石东霞; 蒋忠荣; 殷中琼; 龙兴发; 李太强; 贾仁勇; 杨帆; 徐娇; 张玉群

    2011-01-01

    为筛选印楝油两性不育灭鼠颗粒制剂的最优主药量,并探究其对高原鼠兔的抗生育作用,将主药浓度为300 g/kg和400 g/kg的印楝油两性不育灭鼠颗粒制剂分别进行摄食系数的研究,筛选出适口性较好的制剂,进一步研究适口性较好的制剂对高原鼠兔怀孕率和生殖器官的影响,并用免疫组织化学法检测输卵管和子宫的细胞凋亡情况.结果显示,主药浓度为300g/kg、400 g/kg的颗粒制剂对高原鼠兔的摄食系数分别为0.97和1.87,二者之间差异显著(P<0.05);主药浓度为400 g/kg的印楝油颗粒制剂对高原鼠兔的抗生育率为70%,对睾丸、附睾、子宫、输卵管和卵巢均有明显的病变影响,并且促进子宫细胞凋亡.结果表明,主药浓度为400g/kg的印楝油两性不育灭鼠颗粒制剂适口性良好,对高原鼠兔有良好的抗生育作用,有望用于草原鼠害的防制.%In order to choose the optimal dose of neem oil granules and study its anti-fertility action on Ochotona curzoniae,ingestion coefficients were observed at concentration of 300 g/kg or 400 g/kg of neem oil granules for rodents'ambisexual sterility, respectively,and the apoptotic cells of oviduct and uterine were measured by immunohistochemical method. In result, the ingestion coefficients at concentration of 300 g/kg and 400 g/kg neem oil granules for rodents'ambisexual sterility were 0.97 and 1.87 respectively,and the difference was significant compared with the normal control(P<0.05). The anti-fertility rate was 70% on O. curzoniae at 400 g/kg neem oil granules for rodents'ambisexual sterility,and the dosage caused serious damages on testicle,epididymal duct, hystera,oviduct and ovary, and promoted apoptosis in uterine cells. In conclusion, the 400 g/kg of principle agent concentration of neem oil granules for rodents' ambisexual sterility had good palatability and significant anti-fertility effect, which has implications for the control of rodents

  8. PLATEAU-PATELLA ANGLE: AN OPTION FOR ASSESSING PATELLAR HEIGHT ON PROXIMAL TIBIA OSTEOTOMY

    Science.gov (United States)

    BONADIO, MARCELO BATISTA; TORRES, JÚLIO AUGUSTO DO PRADO; MAZZARO, VICENTE; HELITO, CAMILO PARTEZANI; GOBBI, RICCARDO GOMES; DEMANGE, MARCO KAWAMURA

    2016-01-01

    ABSTRACT Objective: To compare the plateau-patella angle method to the methods already established for patellar height measurement in patients undergoing high tibial osteotomy. Methods: This is a retrospective study of 13 patients undergoing medial opening tibial osteotomy. The patellar height was measured in pre and post-operative radiographs by the methods from Insall-Salvati, Caton-Deschamps, Blackburne-Peel and patella-plateau angle, as well as the tibial slope and length of the patellar tendon. Measurements were performed by two knee surgeons at two different times. Results: The mean age was 41.33 ± 01.09 years old. The average rates of Caton-Deschamps, Blackburne-Peel, Insall-Salvati and plateau-patella angle were, respectively, 1.00; 0.89; 1.10; and 23.15° preoperatively, and 0.89; 0.78; 1.11; and 20.46°, postoperatively. The correlation of Caton-Deschamps, Blackburne-Pell, and Insall-Salvati indexes and plateau-patellar angle interobserver was 0.72 (p <0.001), 0:54 (p <0.001), 0.65 (p <0.001), and 0.67 (w <0.001), respectively. Conclusion: The plateau-patella angle method undergoes changes that are correlated with changes in tibial slope after osteotomy, unlike the classical methods. This fact may lead to overestimate the reduction of patellar height after osteotomy. Level of evidence IV. Case Series. PMID:27217812

  9. Current Progresses in Study of Impacts of the Tibetan Plateau on Asian Summer Climate

    Institute of Scientific and Technical Information of China (English)

    WU Guoxiong; MAO Jiangyu; DUAN Anmin; ZHANG Qiong

    2006-01-01

    The current progresses in the study of impacts of the Tibetan Plateau on Asian summer climate in the last decade are reviewed. By analyzing evolution of the transitional zone between westerly to the north and easterly to the south (WEB), it is shown that due to the strong heating over the Tibetan Plateau in spring, the overturning in the prevailing wind direction from easterly in winter to westerly in summer occurs firstly over the eastern Bay of Bengal (BOB), accompanied with vigorous convective precipitation to its east. The area between eastern BOB and western Indo-China Peninsula thus becomes the area with the earliest onset of Asian monsoon, which may be referred as BOB monsoon in short. It is shown that the summertime circulations triggered by the thermal forcing of the Iranian Plateau and the Tibetan Plateau are embedded in phase with the continental-scale circulation forced by the diabatic heating over the Eurasian Continent. As a result, the East Asian summer monsoon is intensified and the drought climate over the western and central Asian areas is enhanced. Together with perturbations triggered by the Tibetan Plateau,the above scenarios and the associated heating have important influences on the climate patterns over Asia.Furthermore, the characteristics of the Tibetan mode of the summertime South Asian high are compared with those of Iranian mode. Results demonstrate that corresponding to each of the bimodality of the South Asian high, the rainfall anomaly distributions over Asia exhibit different patterns.

  10. Mass exchange between stratosphere and trotosphere over the Tibetan Plateau and its surroundings

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Using NCEP dataset we calculate the exchange of mass across the thermal tropopause by the Wei's method from 1978 to 1997 over the Tibetan Plateau and its surroundings. We also calculate the annual variation of aerosol and ozone of 100 hPa level with the monthly SAGE dataset from July 1988 to December 1993. Results indicate that ( i ) the mass from troposphere to stratosphere is magistral station in summer over the Tibetan Plateau and its surroundings. The air transport reaches the summit in midsummer with two large value centers, which lie in the north of Bengal Bay and southeastern Tibetan Plateau, respectively. A large value center, which lies over the Tibetan Plateau, is smaller than that aforementioned. In winter, the mass transport is from stratosphere to troposphere, and reaches the minimum in January. ( ii ) As far as the 19-year mean cross-tropopause mass exchange from June to September is concerned, the net mass transport is 14.84x1018 kg from troposphere to stratosphere. So the area from the Tibetan Plateau to the Bengal Bay is a channel through which the mass of lower atmosphere layer gets into upper troposphere and lower stratosphere. (iii) The cross-tropopause mass may take the lower level aerosol to the tropopause. Then, the concentration of aerosol near the tropopause becomes larger, which may cause the content of ozone to reduce.

  11. Magnetic properties of Jiaxian red clay sequences from northern Chinese Loess Plateau and its paleoclimatic significance

    Institute of Scientific and Technical Information of China (English)

    QIANG; Xiaoke; AN; Zhisheng; LI; Huamei; CHANG; Hong

    2005-01-01

    Detailed rock magnetism investigation of the Jiaxian red clay sequences indicated that there are common magnetic mineralogy properties in red clay and loess-paleosol sequences from the Chinese Loess Plateau as well as the marked properties of themselves, magnetic minerals mainly with magnetite, maghemite, hematite, and possibly limonite/goethite contributing to the magnetic behavior. Meanwhile, it is found that the strong paleosol in red clay sequences has a lower coercivity and higher content of ultra-fine ferrimagnetic grains than that of the weak paleosol, which is similar to loess and paleosol in upper Wucheng Loess sequences, and indicates that humid conditions and relatively strong pedogenesis play a significant role in the increase of ultra-fine magnetic minerals and transformation of the magnetic minerals. This suggests that, like Quaternary loess-paleosols, the change of characteristics of paleoclimatic conditions of the late Tertiary red clay deposits is fluctuant. In addition, the results of magnetic hysteresis properties show that the applied saturated field for samples from the Jiaxian red clay sequences is higher than that of the samples from eastern and southern Chinese Loess Plateau. It is obviously shown that there exist more hard magnetic minerals and relatively weak biochemical processes in the Jiaxian red clay sequences on northern Chinese Loess Plateau. We conclude that the paleoclimatic environment is different between northern and eastern/southern Chinese Loess Plateau, and it should be more arid in northern Chinese Loess Plateau.

  12. Thorium abundances on the aristarchus plateau: Insights into the composition of the aristarchus pyroclastic glass deposits

    Science.gov (United States)

    Hagerty, J.J.; Lawrence, D.J.; Hawke, B.R.; Gaddis, L.R.

    2009-01-01

    Thorium (Th) data from the Lunar Prospector gamma ray spectrometer (LP-GRS) are used to constrain the composition of lunar pyroclastic glass deposits on top of the Aristarchus plateau. Our goal is to use forward modeling of LP-GRS Th data to measure the Th abundances on the plateau and then to determine if the elevated Th abundances on the plateau are associated with the pyroclastic deposits or with thorium-rich ejecta from Aristarchus crater. We use a variety of remote sensing data to show that there is a large, homogenous portion of the pyroclastics on the plateau that has seen little or no contamination from the Th-rich ejecta of Aristarchus crater. Our results show that the uncontaminated pyroclastic glasses on Aristarchus plateau have an average Th content of 6.7 ppm and ???7 wt % TiO2. These Th and Ti values are consistent with Th-rich, intermediate-Ti yellow glasses from the lunar sample suite. On the basis of this information, we use petrologic equations and interelement correlations for the Moon to estimate the composition of the source region from which the Aristarchus glasses were derived. We find that the source region for the Aristarchus glasses contained high abundances of heat-producing elements, which most likely served as a thermal driver for the prolonged volcanic activity in this region of the Moon. Copyright 2009 by the American Geophysical Union.

  13. Study on the relevance of some of the description methods for plateau-honed surfaces

    Science.gov (United States)

    Yousfi, M.; Mezghani, S.; Demirci, I.; El Mansori, M.

    2014-01-01

    Much work has been undertaken in recent years into the determination of a complete parametric description of plateau-honed surfaces with the intention of making a link between the process conditions, the surface topography and the required functional performances. Different advanced techniques (plateau/valleys decomposition using the normalized Abbott-Firestone curve or morphological operators, multiscale decomposition using continuous wavelets transform, etc) were proposed and applied in different studies. This paper re-examines the current state of developments and addresses a discussion on the relevance of the different proposed parameters and characterization methods for plateau-honed surfaces by considering the control loop manufacturing-characterization-function. The relevance of appropriate characterization is demonstrated through two experimental studies. They consider the effect of the most plateau honing process variables (the abrasive grit size and abrasive indentation velocity in finish-honing and the plateau-honing stage duration and pressure) on cylinder liner surface textures and hydrodynamic friction of the ring-pack system.

  14. 3D surface topography of cylinder liner forecasting during plateau honing process

    Science.gov (United States)

    Reizer, R.; Pawlus, P.

    2011-08-01

    Areal surface topographies after plateau honing process were measured. A correlation analysis of surface texture parameters was then carried out. As the results, the following parameters describing plateau honed cylinder 3D surface topography were selected: amplitude Sq, Sz, spatial: Str, Std, hybrid SΔq as well as functional: Spq, Svq and Smq. 3D surface topographies were modeled. The modeled surface topographies were correctly matched to measured ones in 77% of all analyzed cases. The plateau honing experiment was then carried out using an orthogonal selective research plan. Two machining parameters were input variables: coarse honing pressure pv and plateau honing time t. Chosen cylinder liners texture parameters were output values. As the result of the experiment, regression equations connecting plateau honing process parameters pv and t with recommended 3D surface topography parameters were obtained. Finally, cylinder liner surface topographies were predicted for various values of machining parameters. Proper matching accuracy of modeled to measured textures was assured in 67% of analyzed cases.

  15. 3D surface topography of cylinder liner forecasting during plateau honing process

    Energy Technology Data Exchange (ETDEWEB)

    Reizer, R [University of Rzeszow, Institute of Technology, Rejtana 16A, 35-959 Rzeszow (Poland); Pawlus, P, E-mail: rreizer@univ.rzeszow.pl [Rzeszow University of Technology, W. Pola 2, 35-959 Rzeszow (Poland)

    2011-08-19

    Areal surface topographies after plateau honing process were measured. A correlation analysis of surface texture parameters was then carried out. As the results, the following parameters describing plateau honed cylinder 3D surface topography were selected: amplitude Sq, Sz, spatial: Str, Std, hybrid S{Delta}q as well as functional: Spq, Svq and Smq. 3D surface topographies were modeled. The modeled surface topographies were correctly matched to measured ones in 77% of all analyzed cases. The plateau honing experiment was then carried out using an orthogonal selective research plan. Two machining parameters were input variables: coarse honing pressure p{sub v} and plateau honing time t. Chosen cylinder liners texture parameters were output values. As the result of the experiment, regression equations connecting plateau honing process parameters pv and t with recommended 3D surface topography parameters were obtained. Finally, cylinder liner surface topographies were predicted for various values of machining parameters. Proper matching accuracy of modeled to measured textures was assured in 67% of analyzed cases.

  16. Climate and land use controls on soil organic carbon in the loess plateau region of China.

    Science.gov (United States)

    Dang, Yaai; Ren, Wei; Tao, Bo; Chen, Guangsheng; Lu, Chaoqun; Yang, Jia; Pan, Shufen; Wang, Guodong; Li, Shiqing; Tian, Hanqin

    2014-01-01

    The Loess Plateau of China has the highest soil erosion rate in the world where billion tons of soil is annually washed into Yellow River. In recent decades this region has experienced significant climate change and policy-driven land conversion. However, it has not yet been well investigated how these changes in climate and land use have affected soil organic carbon (SOC) storage on the Loess Plateau. By using the Dynamic Land Ecosystem Model (DLEM), we quantified the effects of climate and land use on SOC storage on the Loess Plateau in the context of multiple environmental factors during the period of 1961-2005. Our results show that SOC storage increased by 0.27 Pg C on the Loess Plateau as a result of multiple environmental factors during the study period. About 55% (0.14 Pg C) of the SOC increase was caused by land conversion from cropland to grassland/forest owing to the government efforts to reduce soil erosion and improve the ecological conditions in the region. Historical climate change reduced SOC by 0.05 Pg C (approximately 19% of the total change) primarily due to a significant climate warming and a slight reduction in precipitation. Our results imply that the implementation of "Grain for Green" policy may effectively enhance regional soil carbon storage and hence starve off further soil erosion on the Loess Plateau.

  17. Sensitivity of the Colorado Plateau to Change: Climate, Ecosystems, and Society

    Directory of Open Access Journals (Sweden)

    Jayne Belnap

    2008-12-01

    Full Text Available The Colorado Plateau is located in the interior, dry end of two moisture trajectories coming from opposite directions, which have made this region a target for unusual climate fluctuations. A multi-decadal drought event some 850 years ago may have eliminated maize cultivation by the first human settlers of the Colorado Plateau, the Fremont and Anasazi people, and contributed to the abandonment of their settlements. Even today, ranching and farming are vulnerable to drought and struggle to persist. The recent use of the Colorado Plateau primarily as rangeland has made this region less tolerant to drought due to unprecedented levels of surface disturbances that destroy biological crusts, reduce soil carbon and nitrogen stocks, and increase rates of soil erosion. The most recent drought of 2002 demonstrated the vulnerability of the Colorado Plateau in its currently depleted state and the associated costs to the local economies. New climate predictions for the southwestern United States include the possibility of a long-term shift to warmer, more arid conditions, punctuated by megadroughts not seen since medieval times. It remains to be seen whether the present-day extractive industries, aided by external subsidies, can persist in a climate regime that apparently exceeded the adaptive capacities of the Colorado Plateau's prehistoric agriculturalists.

  18. Sensitivity of the Colorado Plateau to change: Climate, ecosystems, and society

    Science.gov (United States)

    Schwinning, S.; Belnap, J.; Bowling, David R.; Ehleringer, J.R.

    2008-01-01

    The Colorado Plateau is located in the interior, dry end of two moisture trajectories coming from opposite directions, which have made this region a target for unusual climate fluctuations. A multidecadal drought event some 850 years ago may have eliminated maize cultivation by the first human settlers of the Colorado Plateau, the Fremont and Anasazi people, and contributed to the abandonment of their settlements. Even today, ranching and farming are vulnerable to drought and struggle to persist. The recent use of the Colorado Plateau primarily as rangeland has made this region less tolerant to drought due to unprecedented levels of surface disturbances that destroy biological crusts, reduce soil carbon and nitrogen stocks, and increase rates of soil erosion. The most recent drought of 2002 demonstrated the vulnerability of the Colorado Plateau in its currently depleted state and the associated costs to the local economies. New climate predictions for the southwestern United States include the possibility of a long-term shift to warmer, more arid conditions, punctuated by megadroughts not seen since medieval times. It remains to be seen whether the present-day extractive industries, aided by external subsidies, can persist in a climate regime that apparently exceeded the adaptive capacities of the Colorado Plateau's prehistoric agriculturalists.

  19. The Cenozoic mantle magmatism and motion of lithosphere on the north margin of the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    罗照华; 肖序常; 曹永清; 莫宣学; 苏尚国; 邓晋福; 张文会

    2001-01-01

    Geodynamic properties and evolution of the lithosphere on the north margin of the Tibetan Plateau are recently hot topics to geoscientists in the world. Have the northern plates been subducting underneath the Plateau? It is still an unsolved problem. One of the keys to solving this problem is to understand the genetic processes of Cenozoic magmas on the north margin of the Tibetan Plateau. However, there is no enough evidence supporting the subduction model. In contrast, a series of evidence indicates that collision-induced huge shearing faults and large-scale crust shortening played a main role in lithosphere motion on the north margin of the Tibetan Plateau. The mantle-derived igneous rocks strictly distribute at the intersections of large strike-slip faults on the north margin of the Plateau. Generation of magmas may be related to local exten-sional condition induced by strike-slipping faults, which lead to lithosphere gravitational instability and collapse, as well as upwelling of the deep hot materi

  20. 200-kg large explosive detonation facing 50-km thick crust beneath west Qinling, northeastern Tibetan plateau

    Institute of Scientific and Technical Information of China (English)

    Qiusheng Li; Rui Gao; Haiyan Wang; Jisheng Zhang; Zhanwu Lu; Pengwu Li; Ye Guan; Rizheng He

    2009-01-01

    It is difficult to acquire deep seismic reflection profiles on land using the standard oil-industry acquisition pa-rameters. This is especially true over much of Tibetan plateau not only because of severe topography and rapid variation of both velocity and thickness of near-surface layer, but also strong attenuation of seismic wave through the thickest crust of the Earth. Large explosive sources had been successfully detonated in US, but its application in Tibetan plateau rarely has an example of good quality. Presented herein is the data of a 200-kg single shot we recorded in west Qinling, northeastern Ti-betan plateau. The shot gather data with phenomenal signal-to-noise ratios illustrate the energy of the ProP phase. Although the observations are only limited to the northeastern Tibetan plateau and thus cannot comprise an exhaustive study, they nev-ertheless suggest that large explosions may be a useful exploration tool in Tibetan Plateau where standard seismic sources and profiling methods fail to produce adequate data of low crust.

  1. Numerical study of surface energy partitioning on the Tibetan plateau: comparative analysis of two biosphere models

    Directory of Open Access Journals (Sweden)

    J. Hong

    2010-02-01

    Full Text Available The Tibetan Plateau is a critical region in the research of biosphere-atmosphere interactions on both regional and global scales due to its relation to Asian summer monsoon and El Niño. The unique environment on the Plateau provides valuable information for the evaluation of the models' surface energy partitioning associated with the summer monsoon. In this study, we investigated the surface energy partitioning on this important area through comparative analysis of two biosphere models constrained by the in-situ observation data. Indeed, the characteristics of the Plateau provide a unique opportunity to clarify the structural deficiencies of biosphere models as well as new insight into the surface energy partitioning on the Plateau. Our analysis showed that the observed inconsistency between the two biosphere models was mainly related to: 1 the parameterization for soil evaporation; 2 the way to deal with roughness lengths of momentum and scalars; and 3 the parameterization of subgrid velocity scale for aerodynamic conductance. Our study demonstrates that one should carefully interpret the modeling results on the Plateau especially during the pre-monsoon period.

  2. Preliminary subsurface hydrologic considerations: Columbia River Plateau Physiographic Province. Assessment of effectiveness of geologic isolation systems

    Energy Technology Data Exchange (ETDEWEB)

    Veatch, M.D.

    1980-04-01

    This report contains a discussion of the hydrologic conditions of the Columbia River Plateau physiographic province. The Columbia River Plateau is underlain by a thick basalt sequence. The Columbia River basalt sequence contains both basalt flows and sedimentary interbeds. These sedimentary interbeds, which are layers of sedimentary rock between lava flows, are the main aquifer zones in the basalt sequence. Permeable interflow zones, involving the permeable top and/or rubble bottom of a flow, are also water-transmitting zones. A number of stratigraphic units are present in the Pasco Basin, which is in the central part of the Columbia River Plateau. At a conceptual level, the stratigraphic sequence from the surface downward can be separated into four hydrostratigraphic systems. These are: (1) the unsaturated zone, (2) the unconfined aquifer, (3) the uppermost confined aquifers, and (4) the lower Yakima basalt hydrologic sequence. A conceptual layered earth model (LEM) has been developed. The LEM represents the major types of porous media (LEM units) that may be encountered at a number of places on the Columbia Plateau, and specifically in the Pasco Basin. The conceptual LEM is not representative of the actual three-dimensional hydrostratigraphic sequence and hydrologic conditions existing at any specific site within the Columbia Plateau physiographic province. However, the LEM may be useful for gaining a better understanding of how the hydrologic regime may change as a result of disruptive events that may interact with a waste repository in geologic media.

  3. Prehistoric Human Adaptation to Tibetan Plateau Environment indicated by 151 site in the Qinghai Lake Basin

    Science.gov (United States)

    Zhang, Dongju; Dong, Guanghui; Wang, Qianqian; Ren, Xiaoyan; Chen, Fahu

    2017-04-01

    Current study indicates that Northeastern Tibetan Plateau (NETP) is one of the first widely occupied places by prehistory people on the Tibetan Plateau, which makes NETP very important to understand the human history on the plateau and human adaptation to high elevation environment. Hence, 151 site, a paleo- to Epi-Paleolithic site in the Qinghai Lake basin on NETP, is chosen to excavate. Thousands pieces of animal bones, hundreds pieces of stone artifacts and several possible hearths were unearthed and obtained during two excavation seasons. Carefully redating of the site shows that it was first occupied shortly around 15 ka BP, then reoccupied from 9000-6000 a BP more intensely. Preliminary study of the site suggest that the first appearance of human in Qinghai Lake basin is closely related to the amelioration of the Last Deglaciation and the prevalence of microlithic technology in North China, which may enlighten the study of early human migration on to whole plateau; however, the latter more intense human occupation in 151 site is not only closely related to the warm and stable early-mid Holocene climate but also provoked by early millet agriculture in neighbor low-elevation Loess plateau.

  4. Soil moisture decline due to afforestation across the Loess Plateau, China

    Science.gov (United States)

    Jia, Xiaoxu; Shao, Ming'an; Zhu, Yuanjun; Luo, Yi

    2017-03-01

    The Loess Plateau of China is a region with one of the most severe cases of soil erosion in the world. Since the 1950s, there has been afforestation measure to control soil erosion and improve ecosystem services on the plateau. However, the introduction of exotic tree species (e.g., R. pseudoacacia, P. tabulaeformis and C. korshinskii) and high-density planting has had a negative effect on soil moisture content (SMC) in the region. Any decrease in SMC could worsen soil water shortage in both the top and deep soil layers, further endangering the sustainability of the fragile ecosystem. This study analyzed the variations in SMC following the conversion of croplands into forests in the Loess Plateau. SMC data within the 5-m soil profile were collected at 50 sites in the plateau region via field survey, long-term in-situ observations and documented literature. The study showed that for the 50 sites, the depth-averaged SMC was much lower under forest than under cropland. Based on in-situ measurements of SMC in agricultural plots and C. korshinskii plots in 2004-2014, SMC in the 0-4 m soil profile in both plots declined significantly (p water and require less thinning for sustainable soil conservation without compromising future water resources demands in the Loess Plateau.

  5. Numerical study of surface energy partitioning on the Tibetan Plateau: comparative analysis of two biosphere models

    Directory of Open Access Journals (Sweden)

    J. Hong

    2009-11-01

    Full Text Available The Tibetan Plateau is a critical region in the research of biosphere-atmosphere interactions on both regional and global scales due to its relation to Asian summer monsoon and El Niño. The unique environment on the Plateau provides valuable information for the evaluation of the models' surface energy partitioning associated with the summer monsoon. In this study, we investigated the surface energy partitioning on this important area through comparative analysis of two biosphere models constrained by the in-situ observation data. Indeed, the characteristics of the Plateau provide a unique opportunity to clarify the structural deficiencies of biosphere models as well as new insight into the surface energy partitioning on the Plateau. Our analysis showed that the observed inconsistency between the two biosphere models was mainly related to: 1 the parameterization for soil evaporation; 2 the way to deal with roughness lengths of momentum and scalars; and 3 the parameterization of subgrid velocity scale for aerodynamic conductance. Our study demonstrates that one should carefully interpret the modeling results on the Plateau especially during the pre-monsoon period.

  6. Assessment of satellite rainfall products over the Andean plateau

    Science.gov (United States)

    Satgé, Frédéric; Bonnet, Marie-Paule; Gosset, Marielle; Molina, Jorge; Hernan Yuque Lima, Wilson; Pillco Zolá, Ramiro; Timouk, Franck; Garnier, Jérémie

    2016-01-01

    Nine satellite rainfall estimations (SREs) were evaluated for the first time over the South American Andean plateau watershed by comparison with rain gauge data acquired between 2005 and 2007. The comparisons were carried out at the annual, monthly and daily time steps. All SREs reproduce the salient pattern of the annual rain field, with a marked north-south gradient and a lighter east-west gradient. However, the intensity of the gradient differs among SREs: it is well marked in the Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis 3B42 (TMPA-3B42), Precipitation Estimation from remotely Sensed Information using Artificial Neural Networks (PERSIANN) and Global Satellite Mapping of Precipitation (GSMaP) products, and it is smoothed out in the Climate prediction center MORPHing (CMORPH) products. Another interesting difference among products is the contrast in rainfall amounts between the water surfaces (Lake Titicaca) and the surrounding land. Some products (TMPA-3B42, PERSIANN and GSMaP) show a contradictory rainfall deficit over Lake Titicaca, which may be due to the emissivity contrast between the lake and the surrounding lands and warm rain cloud processes. An analysis differentiating coastal Lake Titicaca from inland pixels confirmed this trend. The raw or Real Time (RT) products have strong biases over the study region. These biases are strongly positive for PERSIANN (above 90%), moderately positive for TMPA-3B42 (28%), strongly negative for CMORPH (- 42%) and moderately negative for GSMaP (- 18%). The biases are associated with a deformation of the rain rate frequency distribution: GSMaP underestimates the proportion of rainfall events for all rain rates; CMORPH overestimates the proportion of rain rates below 2 mm day- 1; and the other products tend to overestimate the proportion of moderate to high rain rates. These biases are greatly reduced by the gauge adjustment in the TMPA-3B42, PERSIANN and CMORPH products, whereas a

  7. Abrupt uplift of Tibetan Plateau at the end of early Pleistocene and Australasian impact event

    Institute of Scientific and Technical Information of China (English)

    REN Shoumai; LIU Yongjiang; GE Xiaohong

    2009-01-01

    The latest sharp uplift of the Tibetan Plateau and adjacent mountains occurred at the end of the early Pleistocene. The uplift of the Plateau resulted from Late Mesozoic- -Cenozoic compressional structure due to the subduction of the Indian Plate beneath the Asian continent. This event definitively effected the formation of basin-mountain relief, Cenozoic basin deformation, large scale aridity and desertification of western China. The Australasian meteorites impact event happened ca. 0.8 Ma ago, located in the triangle area of the Indian Ocean ridge (20°S/67°E). The impact may have resulted in an acceleration of speeding of the Indian Ocean ridge pushing the Indian Plate to subduct rapidly northward. Thus, the impact event can give reasonable explanation for the dynamic background of the latest rapid uplift of the Tibetan Plateau and the continental deformation of western China and even of the Middle Asia.

  8. Remote sensing of severe convective storms over Qinghai-Xizang Plateau

    Science.gov (United States)

    Hung, R. J.; Liu, J. M.; Tsao, D. Y.; Smith, R. E.

    1984-01-01

    The American satellite, GOES-1 was moved to the Indian Ocean at 58 deg E during the First GARP Global Experiment (FGGE). The Qinghai-Xizang Plateau significantly affects the initiation and development of heavy rainfall and severe storms in China, just as the Rocky Mountains influence the local storms in the United States. Satelite remote sensing of short-lived, meso-scale convective storms is particularly important for covering a huge area of a high elevation with a low population density, such as the Qinghai-Xizang Plateau. Results of this study show that a high growth rate of the convective clouds, followed by a rapid collapse of the cloud top, is associated with heavy rainfall in the area. The tops of the convective clouds developed over the Plateau lie between the altitudes of the two tropopauses, while the tops of convective clouds associated with severe storms in the United States usually extend much above the tropopause.

  9. Crustal rheology controls on the Tibetan plateau formation during India-Asia convergence

    Science.gov (United States)

    Chen, Lin; Capitanio, Fabio A.; Liu, Lijun; Gerya, Taras V.

    2017-07-01

    The formation of the Tibetan plateau during the India-Asia collision remains an outstanding issue. Proposed models mostly focus on the different styles of Tibetan crustal deformation, yet these do not readily explain the observed variation of deformation and deep structures along the collisional zone. Here we use three-dimensional numerical models to evaluate the effects of crustal rheology on the formation of the Himalayan-Tibetan orogenic system. During convergence, a weaker Asian crust allows strain far north within the upper plate, where a wide continental plateau forms behind the orogeny. In contrast, a stronger Asian crust suppresses the plateau formation, while the orogeny accommodates most of the shortening. The stronger Asian lithosphere is also forced beneath the Indian lithosphere, forming a reversed-polarity underthrusting. Our results demonstrate that the observed variations in lithosphere deformation and structures along the India-Asia collision zone are primarily controlled by the strength heterogeneity of the Asian continental crust.

  10. A first paleomagnetic and rock magnetic investigation of calcareous nodules from the Chinese Loess Plateau

    Science.gov (United States)

    Yang, T.; Hyodo, M.; Yang, Z.; Sun, Z.

    2005-01-01

    A detailed paleomagnetic and rock magnetic investigation was carried out on calcareous nodule layers embed-ded in the loess-paleosol sequences near Baoji city, southern Chinese Loess Plateau. The anisotropy of low-field magnetic susceptibility confirms that calcareous nodules retain the primary sedimentary fabric of original de-posits. Rock magnetic properties demonstrate that calcareous nodules have the same mineralogy and grain sizes as loess-paleosol deposits. Characteristic remanent magnetizations of calcareous nodules have directions consis-tent with those of adjacent loess and paleosol deposits. The Punaruu event, previously found from loess deposits in the upper part of loess unit L13 in Weinan, southern Chinese Loess Plateau, is observed at the corresponding stratigraphic level in the calcareous nodule layer. These observations indicate that the calcareous nodule layers preserve primary remanent magnetizations of original deposits before calcification, and that they can contribute to paleomagnetic studies in the Chinese Loess Plateau.

  11. On the Variation of NDVI with the Principal Climatic Elements in the Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Yunchuan Yang

    2013-04-01

    Full Text Available Temperature and precipitation have been separately reported to be the main factors affecting the Normalized Difference Vegetation Index (NDVI in the Tibetan Plateau. The effects of the main climatic factors on the yearly maximum NDVI (MNDVI in the Tibetan Plateau were examined on different scales. The result underscored the observation that both precipitation and temperature affect MNDVI based on weather stations or physico-geographical regions. Precipitation is the main climatic factor that affects the vegetation cover in the entire Tibetan Plateau. Both annual mean precipitation and annual mean precipitation of the growing period are related with MNDVI, and the positive correlations are manifested in a linear manner. By comparison, the weakly correlated current between MNDVI and all the temperature indexes is observed in the study area.

  12. The Influence of Low-frequency Oscillation Propagation of the Tibetan Plateau Vortex on Rainstorm Downstream

    Science.gov (United States)

    Xiao, Tiangui; Wang, Chao; La, Jia; Du, Jun; Zhang, Kairong

    2017-04-01

    Based on Tibetan Plateau vortex data, ERA-Interim and NCEP/NCAR reanalysis data, the characteristics of Tibetan Plateau vortex and the relationship with Low-Frequency Oscillation (LFO) from 2003 to 2012 were investigated. The heavy rainstorm occurred in Sichuan from June 29th to July 2nd in 2013, caused by the LFO, was studied. Besides, the signal of LFO, energy transmission and those influence to rainstorm were also investigate. The main conclusions are as follows: (1)Most of Tibetan Plateau vortex generate in eastern plateau, located at Tanggula Mountains, Zaduo, Dege, Qumalai and Qaidam. The moving-out Tibetan Plateau vortex mainly generate in Qumalai and most vortex occurrences during April to September. There are three directions of moving-out vortex paths: northeast, southeast and east. The areas which plateau vortex moving into are mainly distributed in Gansu, Sichuan, Shaanxi and Ningxia. (2)The zonal wind at 500hPa in plateau key region has a significant main 10-30d oscillation, with the secondly significant oscillation in 30-50d and the third in 70-90d. The relative vorticity at 500hPa in plateau key region has a significant main 30-50d oscillations, with the secondly significant oscillation in 10-30d. The 30-50d oscillation phase zone with weak westerly oscillation zone of 500hPa, and the 10-30d oscillation positive phase zone with weak oscillation zone of 500hPa are benefit to vortex generation. The 30-50d oscillation of zonal wind at 500hPa provides necessary circulation background for generation of plateau vortex, and positive phase region of 10-30d oscillation of relative vorticity at 500hPa provide necessary dynamic background conditions for it. (3) Comparing with the high frequency oscillation vortex, 10-25d low-frequency vortex is not significant at 500hPa before merging into the basin vortex. However, after merging into the basin vortex, there is a significant relationship between low-frequency vortex and the process of development, weakening and

  13. Monthly Water Budget of Small Basin in Northern of Loess Plateau,China

    Institute of Scientific and Technical Information of China (English)

    HUANG Jinbai; HINOKIDANI Osamu; YASUDA Hiroshi; Kimura Reiji; ZHENG Jiyong

    2010-01-01

    The objective of this study was to analyze the water budget of a small basin in the northern of Loess Plateau. A small basin, Liudaogou in the northern Loess Plateau was chosen as the study area. The numerical calculation of surface runoff was applied to results of the field survey, and components of monthly water budget were estimated. The unit area of 1 km was selected as the index area for the estimation. A component of habitant water consumption was added to the water budget to consider the contribution of human activity. Results indicated that the water storage was negative in May, June and July while the annual amount was approximately 0.0. Evaportanspiration attained maximum in August and its annual total accounted for 74.2% of annual precipitation. Results of this study are significant for the sustainable water conservation and utilization in the northern of Loess Plateau where annual water resources are relatively deficient.

  14. A comparison of pelagic, littoral, and riverine bacterial assemblages in Lake Bangongco, Tibetan Plateau.

    Science.gov (United States)

    Liu, Yongqin; Priscu, John C; Yao, Tandong; Vick-Majors, Trista J; Michaud, Alexander B; Jiao, Nianzhi; Hou, Juzhi; Tian, Lide; Hu, Anyi; Chen, Zhong-Qiang

    2014-08-01

    Lakes of the Tibetan Plateau lack direct anthropogenic influences, providing pristine high-altitude (> 4000 m) sites to study microbial community structure. We collected samples from the pelagic, littoral, and riverine zones of Lake Bangongco, located on the western side of the Plateau, to characterize bacterial community composition and geochemistry in three distinct, but hydrologically connected aquatic environments during summer. Bacterial community composition differed significantly among zones, with communities changing from riverine zones dominated by Bacteroidetes to littoral and pelagic zones dominated by Gammaproteobacteria. Community composition was strongly related to the geochemical environment, particularly concentrations of major ions and total nitrogen. The dominance of Gammaproteobacteria in the pelagic zone contrasts with typical freshwater bacterial communities as well as other lakes on the Tibetan Plateau. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  15. "Greatest lake period"and its palaeo-environment on the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The“greatest lake perion”means that the lakes are in the stage of their maximum areas.As the paleo lake shorelines are widely distributed in the lake basins on the Tibetan Plateau,the lake areas during the “greatest lake period”may be inferred by the last highest lake shorelines.They are several,even tens times larger than that at present.According to the analyses of tens of lakes on the Plateau,most dating data fell into the range of 40-25 ka BP,some lasted to 20 ka BP.It was corresponded to the stage 3 of marine isotope and interstitial of last glaciation.The occurrence of maximum areas of lakes marked the very humid period on the Plateau and was also related to the stronger summer monsoon during that period.

  16. STATUS, CAUSES AND COMBATING SUGGESTIONS OF SANDY DESERTIFICATION IN QINGHAI-TIBET PLATEAU

    Institute of Scientific and Technical Information of China (English)

    LIU Yi-hua; DONG Guang-rong; LI Sen; DONG Yu-xiang

    2005-01-01

    The Qinghai-Tibet Plateau is one of the major sandy desertification regions of China. Based on the recent investigation on sandy desertification, this paper analyses the status such as the type, area, distribution and damage of sandy land desertification in the plateau. Through the analysis on the factors affecting sandy desertification in the region's natural and socio-economic systems as well as the processes and their interrelations, it can be concluded that sandy desertification in the Qinghai-Tibet Plateau resulted from the combined actions of normal natural sand drift processes, natural sandy desertification processes caused by climatic changes and man-made sandy desertification caused by improper human activities. In addition, it also predicts the possible developmental trend including the increase in desertification area and the enhancement in desertification developmental degree with the exacerbation of the complex processes, and finally puts forward some strategic suggestions to combat sandy desertification in the coming years.

  17. Constraining properties of GRB magnetar central engines using the observed plateau luminosity and duration correlation

    CERN Document Server

    Rowlinson, A; Dainotti, M; O'Brien, P T; Wijers, R A M J; van der Horst, A J

    2014-01-01

    An intrinsic correlation has been identified between the luminosity and duration of plateaus in the X-ray afterglows of Gamma-Ray Bursts (GRBs; Dainotti et al. 2008), suggesting a central engine origin. The magnetar central engine model predicts an observable plateau phase, with plateau durations and luminosities being determined by the magnetic fields and spin periods of the newly formed magnetar. This paper analytically shows that the magnetar central engine model can explain, within the 1$\\sigma$ uncertainties, the correlation between plateau luminosity and duration. The observed scatter in the correlation most likely originates in the spread of initial spin periods of the newly formed magnetar and provides an estimate of the maximum spin period of ~35 ms (assuming a constant mass, efficiency and beaming across the GRB sample). Additionally, by combining the observed data and simulations, we show that the magnetar emission is most likely narrowly beamed and has $\\lesssim$20% efficiency in conversion of rot...

  18. Monitoring drought in the Monglian Plateau based on NDVI_Ts general space, 2000-2010

    Science.gov (United States)

    Cao, Xiaoming; Wang, Juanle; Gao, Zhiqiang; Ning, Jicai; Shi, Runhe; Gao, Wei

    2013-09-01

    This paper presents a new drought assessment method by modifying the NDVI-Ts space, which named NDVI-Ts general space. Based on this method, the general dry side and wet side equation were established for the period of 2000 and 2010 in the Mongolian Plateau. The results showed that: 1) the NDVI-Ts general space was more stable for monitoring drought than that for the single time Remote Sensing data; 2) Drought mainly distributed in the Mongolian Plateau, In Mongolian Plateau, there was about 75% area of drought; 3) Drought changed in the period of 2000 and 2010. In the year of 2003, the area of severe drought is the smallest. In 2001, the drought is the most serious. The results showed that, the distribution of drought was different in different year. There may be close correlation between the occurrence of drought and precipitation.

  19. The intracrustal structure beneath the Owyhee Plateau, Oregon, from receiver function analysis

    Science.gov (United States)

    Hou, T.; Chen, C.; James, D. E.; Fouch, M. J.

    2013-12-01

    The Owyhee Plateau straddles southeastern Oregon, southwestern Idaho, and northern Nevada, and is an isolated block of older, and less modified, continental lithosphere relative to bordering geologic terranes. Previous seismic studies have characterized the Owyhee Plateau as having thickened crust with low Poisson's ratio and high intracrustal S-wave velocities, and distinct, albeit thin, mantle lithosphere. Significant tectonomagmatic activity, including extension in the northern Great Basin, and intraplate volcanism is present on the margins of the Plateau, but very little volcanism takes place within the Plateau itself. The volcanism is expressed as two prominent age-progressive volcanic tracks, the Snake River Plains-Yellowstone and the High Lava Plains, both of which appear to have originated from near the Owyhee Plateau at approximately 12 Ma. Recent ambient noise tomography and scattered-wave imaging reveal the presence of irregular high velocity layering in the Owyhee mid-crust, but the extent and properties of this feature, and its role in the tectonic evolution of the Owyhee Plateau, remain elusive. In this study, we perform detailed single station Ps receiver function analysis to better constrain the discontinuity structures within the Owyhee crust. We use teleseismic waveform data recorded at 28 High Lava Plains seismic array and 12 USArray Transportable Array broadband stations from 2006 to 2009. Preliminary results show coherent signals of converted phase at ~20 km depth, indicating the presence of a positive velocity discontinuity, which may mark the upper bound of the high velocity layer imaged in previous studies. We consider and examine possible effects of seismic anisotropy on our results and are also conducting synthetic experiments to further constrain the properties of this feature.

  20. Combining CHAMP and Swarm Satellite Data to Invert the Lithospheric Magnetic Field in the Tibetan Plateau.

    Science.gov (United States)

    Qiu, Yaodong; Wang, Zhengtao; Jiang, Weiping; Zhang, Bingbing; Li, Fupeng; Guo, Fei

    2017-01-26

    CHAMP and Swarm satellite magnetic data are combined to establish the lithospheric magnetic field over the Tibetan Plateau at satellite altitude by using zonal revised spherical cap harmonic analysis (R-SCHA). These data are integrated with geological structures data to analyze the relationship between magnetic anomaly signals and large-scale geological tectonic over the Tibetan Plateau and to explore the active tectonic region based on the angle of the magnetic anomaly. Results show that the model fitting error is small for a layer 250-500 km high, and the RMSE of the horizontal and radial geomagnetic components is better than 0.3 nT. The proposed model can accurately describe medium- to long-scale lithospheric magnetic anomalies. Analysis indicates that a negative magnetic anomaly in the Tibetan Plateau significantly differs with a positive magnetic anomaly in the surrounding area, and the boundary of the positive and negative regions is generally consistent with the geological tectonic boundary in the plateau region. Significant differences exist between the basement structures of the hinterland of the plateau and the surrounding area. The magnetic anomaly in the Central and Western Tibetan Plateau shows an east-west trend, which is identical to the direction of the geological structures. The magnetic anomaly in the eastern part is arc-shaped and extends along the northeast direction. Its direction is significantly different from the trend of the geological structures. The strongest negative anomaly is located in the Himalaya block, with a central strength of up to -9 nT at a height of 300 km. The presence of a strong negative anomaly implies that the Curie isotherm in this area is relatively shallow and deep geological tectonic activity may exist.

  1. Experimental study on soil CO2 emission in the alpine grassland ecosystem on Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xianzhou; SHI Peili; LIU Yunfen; OUYANG Hua

    2005-01-01

    The Tibetan Plateau, the Roof of the World, is the highest plateau with a mean elevation of 4000 m. It is characterized by high levels of solar radiation, low air temperature and low air pressure compared to other regions around the world. The alpine grassland, a typical ecosystem in the Tibetan Plateau, is distributed across regions over the elevation of 4500 m. Few studies for carbon flux in alpine grassland on the Tibetan Plateau were conducted due to rigorous natural conditions. A study of soil respiration under alpine grassland ecosystem on the Tibetan Plateau from October 1999 to October 2001 was conducted at Pangkog County, Tibetan Plateau (31.23°N, 90.01°E, elevation 4800 m). The measurements were taken using a static closed chamber technique, usually every two weeks during the summer and at other times at monthly intervals. The obvious diurnal variation of CO2 emissions from soil with higher emission during daytime and lower emission during nighttime was discovered. Diurnal CO2 flux fluctuated from minimum at 05:00 to maximum at 14:00 in local time. Seasonal CO2 fluxes increased in summer and decreased in winter, representing a great variation of seasonal soil respiration. The mean soil CO2 fluxes in the alpine grassland ecosystem were 21.39 mgCO2 · m-2 · h-1, with an average annual amount of soil respiration of 187.46 gCO2 · m-2 · a-1. Net ecosystem productivity is also estimated, which indicated that the alpine grassland ecosystem is a carbon sink.

  2. Minimal erosion in central Tibet since the Eocene and implications for plateau development

    Science.gov (United States)

    Rohrmann, Alexander; Kapp, Paul; Reiners, Peter; Gyunn, Jerome; Carrapa, Barbara

    2010-05-01

    The growth history of the Tibetan plateau remains elusive, despite its importance for assessing mechanisms of continental lithosphere deformation and associated changes in surface elevation and climate system dynamics. In contrast to the actively growing plateau margins, the interior of the modern Tibetan plateau is characterized by extremely low erosion rates. We present the first apatite (U-Th)/He low-temperature thermochronologic results from samples collected away from late Cenozoic rifts in the Lhasa and Qiangtang terranes of central Tibet. These data are complemented by apatite fission-track and K-feldspar 40Ar/39Ar results, to construct continuous cooling histories. The data indicate that in most places, low erosion rates (< ~0.05 mm/yr) were established by the time India collided with Asia ~50 Myr ago, following earlier episodes of more rapid exhumation that correspond in time with documented Cretaceous - Eocene thrust belt activity. Findings of large-magnitude (≥50%) upper-crustal shortening and substantial exhumation prior to 50 Myr ago, followed by minimal subsequent denudation, support the establishment of a proto-plateau in central Tibet prior to the Indo-Asian collision. Collectively, the exhumation history of central Tibet, away from the influence of late Cenozoic rifts, contrasts sharply with that of the Lhasa region in the southern Lhasa terrane and near the modern margins of the plateau which show prominent erosional signatures of the Indo-Asian collision. Any viable model of plateau development must explain these prominent spatial variations in exhumation history as well as the lack of a corresponding expression in the modern topography.

  3. Some practical notes on the land surface modeling in the Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    K. Yang

    2009-05-01

    Full Text Available The Tibetan Plateau is a key region of land-atmosphere interactions, as it provides an elevated heat source to the middle-troposphere. The Plateau surfaces are typically characterized by alpine meadows and grasslands in the central and eastern part while by alpine deserts in the western part. This study evaluates performance of three state-of-the-art land surface models (LSMs for the Plateau typical land surfaces. The LSMs of interest are SiB2 (the Simple Biosphere, CoLM (Common Land Model, and Noah. They are run at typical alpine meadow sites in the central Plateau and typical alpine desert sites in the western Plateau.

    The identified key processes and modeling issues are as follows. First, soil stratification is a typical phenomenon beneath the alpine meadows, with dense roots and soil organic matters within the topsoil, and it controls the profile of soil moisture in the central and eastern Plateau; all models, when using default parameters, significantly under-estimate the soil moisture within the topsoil. Second, a soil surface resistance controls the surface evaporation from the alpine deserts but it has not been reasonably modeled in LSMs; an advanced scheme for soil water flow is implemented in a LSM, based on which the soil resistance is determined from soil water content and meteorological conditions. Third, an excess resistance controls sensible heat fluxes from dry bare-soil or sparsely vegetated surfaces, and all LSMs significantly under-predict the ground-air temperature gradient, which would result in higher net radiation, lower soil heat fluxes and thus higher sensible heat fluxes in the models. A parameterization scheme for this resistance has been shown to be effective to remove these biases.

  4. The seismic Moho structure of Shatsky Rise oceanic plateau, northwest Pacific Ocean

    Science.gov (United States)

    Zhang, Jinchang; Sager, William W.; Korenaga, Jun

    2016-05-01

    Oceanic plateaus are large igneous provinces formed by extraordinary eruptions that create thick oceanic crust, whose structure is poorly known owing to the lack of deep-penetration seismic data. Multichannel seismic (MCS) reflection and wide-angle refraction data allow us to show Moho structure beneath a large part of the Shatsky Rise oceanic plateau in the northwest Pacific Ocean. Moho reflectors in the two data sets can be connected to trace the interface from the adjacent abyssal plain across much of the interior. The reflectors display varied character in continuity, shape, and amplitude, similar to characteristics reported in other locations. Beneath normal crust, the Moho is observed at ∼13 km depth (∼7 km below the seafloor) in MCS data and disappears at ∼20 km depth (∼17 km below the seafloor) beneath the high plateau. Moho at the distal flanks dips downward towards the center with slopes of ∼0.5°-1°, increasing to 3°-5° at the middle flanks. Seismic Moho topography is consistent with Airy isostasy, confirming this widely-applied assumption. Data from this study show that crustal thickness between the massifs in the interior of the plateau is nearly twice normal crustal thickness, despite the fact that this crust records apparently normal seafloor spreading magnetic lineations. The Moho model allows improved estimates of plateau area (5.33 ×105 km2) and volume (6.90 ×106 km3), the latter assuming that the entire crust was formed by Shatsky Rise volcanism because the massifs formed at spreading ridges. This study is unique in showing Moho depth and structure over an extraordinarily large area beneath an oceanic plateau, giving insight to plateau structure and formation.

  5. Will the Tibetan Plateau warming depend on elevation in the future?

    Science.gov (United States)

    Guo, Donglin; Yu, Entao; Wang, Huijun

    2016-04-01

    Elevation-dependent warming, greater warming at higher elevations, tends to accelerate the ablation of solid water reserves on the Tibetan Plateau and is thus expected to affect the sustainable water supply of the plateau. In the context of a global climate that is predicted to continue to warm, whether elevation-dependent warming exists on the Tibetan Plateau in the future and, if so, what its characteristics and mechanisms are, are important issues that have not yet been fully assessed. Using six sets of high-resolution outputs from dynamical downscaling simulations based on regional climate models, we investigated the future situation regarding the elevation dependency of climate warming on the Tibetan Plateau. The simulated air temperature trends from the six simulations are validated using meteorological station observations. The trends from only two simulations are selected for analysis due to their statistically significant correlation with the observations. The warming rate first increases to a peak and then slightly declines along with elevation increasing from 2000 m to 5600 m. The peak of the warming rate is reached at variable elevations (4400-5200 m), which depends on the intensity of the warming. The elevation at which this peak occurs increases when the warming intensifies. Such elevation-dependent warming is mostly caused by the decrease in upward short-wave radiation due to the depletion of snow based on surface energy budget analysis. These results provide some understanding of the future elevation-dependent warming on the Tibetan Plateau, which will be useful for evaluating the sustainability of water resources of the Tibetan Plateau water-affected area.

  6. A Case Study of a Heavy Rain over the Eastern Tibetan Plateau

    Science.gov (United States)

    Chen, Q.

    2016-12-01

    A Case Study of a Heavy Rain over the Eastern Tibetan Plateau Quan-Liang Chen1, Qichao Long1, Ke Gui1, Ying Zhang2College of Atmospheric Science/Plateau Atmospheric and Environment Laboratory of Sichuan Province, Chengdu University of Information Technology, Chengdu 610225, China 2 School of Earth and Space Sciences/CAS Key Laboratory of Atmospheric Composition and Optical Radiation, University of Science and Technology of China, Hefei 230026, China Abstract: The case study can improve our understanding of precipitation over the Tibetan Plateau. This paper systematically studies a heavy rain occurred on August 5, 2014 over the eastern Tibetan Plateau (31°N 35°N, 96°E 103°E) using the orbital data of Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR). The characteristics of horizontal distribution and vertical structure of the precipitation system, convective storm top altitude and the types of rain, the mean rainfall profile and the influence of water vapor before and after the rainfall are investigated. The results suggest that the precipitation was strongly affected by the Tibetan Plateau terrain. The near-surface precipitation rate and storm top altitudes have a positive correlation. And the convection is powerful so that the convective storm top altitude can reach 16 km. Furthermore, the water vapor content has obvious changes in the upper troposphere and lower stratosphere (UTLS) area. The maximum rainfall rate appears at about 5.5 km. The deep weak convective precipitation has the largest contribution to the total precipitation. Key words: Tibetan Plateau; TRMM; precipitation; vertical structure; water vapor content; terrain

  7. Petrology and Bulk Chemistry of Modern Bed Load Sediments From Rivers Draining the Eastern Tibetan Plateau

    Science.gov (United States)

    Borges, J. B.

    2003-12-01

    We studied river bed load petrology and bulk sediment chemistry of the headwaters of the Changjiang, Huang He and Red rivers in China and Vietnam. These rivers drain the eastern and southeastern parts of the Tibetan Plateau which includes part of the Indian-Eurasian suture zone. The eastern Tibetan Plateau is dominated by marine sedimentary rocks with a few scattered intrusive igneous outcrops, while the suture zone is characterized by a mixture of high-grade metamorphic, ultramafic, granitic, volcanic arc and marine sedimentary rocks. The arithmetic average for Qt: Ft: Rft along the suture zone varies from 56:2:42 along the Red River Fault (RRF) zone to 38:6:56 in the interior of the continent, while sands from rivers draining the plateau average 32:8:60. The sands analyzed in this study are relatively immature compared to most data available from most rivers in the tropics. The average Chemical Index of Alteration (CIA) for samples from the RRF suture zone (0.62) is similar to that of rivers draining other tropical regions like the Niger, Chao Phraya, Mekong, Ganges, Amazon and Brahmaputra. The CIA values from the RRF zone are also significantly different from the rest of the suture zone (0.36) and the plateau area (0.38). The difference can be attributed to the combined effect of relief and precipitation. The RRF lies in the Red River drainage and receives ˜1820 mm of precipitation annually, while the plateau area averages ˜620 mm annually. In the case of the Red River drainage, the relief combined with higher humidity can increase physical weathering and reduce the residence time of sediment in the river drainage, therefore, continuously replacing the sediment transported out of the drainage by freshly weathered immature materials. In the plateau area, lower precipitation and runoff may limit sediment transport and chemical weathering leading to sediment immaturity.

  8. Exhumation history of the southern Altiplano plateau (southern Bolivia) constrained by apatite fission track thermochronology

    Science.gov (United States)

    Ege, H.; Sobel, E. R.; Scheuber, E.; Jacobshagen, V.

    2007-02-01

    Although the structural geometry of the Cenozoic Altiplano-Puna plateau in the central Andes is well defined, the temporal evolution of this contractile deformation is poorly constrained. To address this shortcoming, we used apatite fission track thermochronology (AFT) to quantify the cooling and exhumation history along a transect at 21°S in southern Bolivia, through the deformed intermontane Altiplano basin, the doubly vergent thrust belt of the Eastern Cordillera and the inner foreland thrust belt east of the plateau (Interandean Zone). Thermal history modeling combined with published balanced cross sections and stratigraphic data constrain exhumation histories. Exhumation started during the late Eocene (40-36 Ma) in the central Eastern Cordillera, possibly due to bivergent thrusting and Cretaceous rift structure inversion. During the early Oligocene (33-27 Ma), exhumation spread across the study area as the current boundary thrusts of the Eastern Cordillera were activated. The inner west vergent thrust system became active in irregular order until circa 20 Ma, whereas the east vergent Interandean thrust belt formed by eastward propagating deformation since circa 30 Ma. Plateau exhumation continued at ˜0.2 mm/yr until shortening terminated by 11-7 Ma. Shortening within the plateau since circa 30 Ma did not evolve by lateral accretion of thrust wedges; the propagating deformation style is spatially confined to the foreland thrust belt, which initiated coeval to plateau deformation (Interandean Zone) but propagated mainly after circa 10 Ma (Subandean Zone). Early Oligocene plateau-wide tectonically driven exhumation suggests that subduction-related processes had already thermally weakened the continental lithosphere prior to the 27-25 Ma onset of volcanic activity.

  9. A quarter century of research on the Colorado Plateau: a compilation of the Colorado Plateau Biennial Conference Proceedings for 1993-2015

    Science.gov (United States)

    Van Riper, Charles; Drost, Charles A.; Selleck, S. Shane

    2015-01-01

    This Open-File Report is a compilation of the work published in the Colorado Plateau Biennial Conference book series over the span of the past nearly quarter century (conferences held between 1991–2011). The primary focus of the conferences has been to work toward integrating new science findings into management of the region’s natural and cultural resources. This conference and book series has begun a tradition of cooperation and community, bridging cultural, social, and biophysical research interests and addressing the needs of scientists and land managers working in a complex geographic area. We include here the abstracts for each of the 11 books in the series, as well as links to files with comprehensive literature citations and author listings. The goal of this compilation is to encourage further cooperation and communication on research and management issues of the Colorado Plateau among researchers, land managers, Native American tribes, and the public.   

  10. Livelihood Vulnerability Assessment Of Farmers and Nomads in Eastern Ecotone of Tibetan Plateau

    Science.gov (United States)

    Yan, J.; Zhang, Y.

    2011-12-01

    Livelihood vulnerability assessment provides a scientific basis for anti-poverty of people and regional sustainable development in vulnerable area. Although there are massive discussions on concept of vulnerability, it is still difficult to make it quantitative and to carry out comprehensive appraise. Vulnerability assessments based on sustainable livelihood frame are widely accepted in case studies for attentions to vulnerable groups. However, these case studies are always on regional scale and never reflect how climate change affects people's livelihood and adaptive capability of people. It is necessary to seek vulnerable assessment index system and means based on livelihood process of local people. This paper develops a livelihood vulnerability assessment index system on the basis of sustainable livelihood framework and appraises livelihood vulnerability values of 11 townships, using data of 879 sample households. Livelihood vulnerability assessment index system reflects main risks, livelihood assets and adaptation strategies of local people and government. The results show that livelihood vulnerability level of plateau region is higher than that of mountain to plateau region and mountain gorge region. Manzhang Township in plateau region is the most vulnerable township and nomads there cannot cope with risks of climate change, meadow degeneration and herbs degradation. Upper part of mountain to plateau region and the whole plateau region have high livelihood vulnerability values and local nomads would not cope with risks if no measures are taken by government. The driving forces of livelihood vulnerability include strikes of risks and deficiency of livelihood assets and adaptive capability. Farmers and nomads in high mountain gorge region and lower part of mountain to plateau region can cope with these risks, meanwhile, there are more employment opportunities in second and tertiary industries are needed to help them realize livelihood diversification. Therefore

  11. Ozone mini-hole occurring over the Tibetan Plateau in December 2003

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    By analyzing the total ozone data from TOMS and ground-based observations, it is found that a large area with extremely low ozone occurred over the Tibetan Plateau during December 14-17, 2003. After correcting the bias in TOMS data, the area with the total ozone < 220 DU is found to be over 2500000 km2, and the minimum value is only 190 DU. It is the first time that an ozone mini-hole or an extremely low ozone event is found to occur over the Tibetan Plateau.

  12. [Responses of spatial distribution pattern of Artemisia ordosica population to the precipitation gradient on Ordos Plateau].

    Science.gov (United States)

    Li, Qiu-shuang; Zhang, Chao; Wang, Fei; Lai, Li-ming; Zhang, Li; Li, Wen-ting; Bai, Hua; Zheng, Yuan-run

    2009-09-01

    Five sites along the precipitation gradient (336-249 mm x a(-1)) from east to west in Ordos Plateau were selected to study the spatial distribution pattern of Artemisia ordosica population and its responses to the precipitation gradient by the methods of variance mean ratio, aggregative index, and point pattern analysis. The reduction of precipitation affected the spatial distribution pattern of A. ordosica population significantly. With decreasing precipitation gradient, the spatial pattern of A. ordosica population changed from uniform to random in small scale, and from random to clumpy in large scale, suggesting that in the ecological restoration of Ordos Plateau, a rational arrangement of A. ordosica should be made.

  13. On the relationship between environmental aridization of the Loess Plateau and soil water in loess

    Institute of Scientific and Technical Information of China (English)

    杨文治; 邵明安; 彭新德; 夏卫生

    1999-01-01

    The similarity between loess palaeo-environment and geographic distribution of modern bioclimatic zones is taken as a starting point; the relationship between the environmental aridization and soil water in loess is discussed from the point view of the soil water energy status and their soil water physical characteristics of modern loessial soils on the Loess Plateau. The soil water content becomes less and less from southeast to northwest, which not only provides favorable conditions for dust production by wind of loess origin, but also reveals that there is obviously a directional change in the environmental drought intensity of the Loess Plateau.

  14. Numerical investigation of the influence of gravity on the Rayleigh-Plateau jet instability

    Science.gov (United States)

    Rosello, M.; Maîtrejean, G.; Roux, D. C. D.; Jay, P.

    2016-12-01

    Controlled jet breakup processes are commonly used in many fields of industrial applications, such as inkjet printing, spray painting, and fuel injection. Most of these applications rely on the accurate prediction of the size of droplets resulting from breakup. While many parameters influence the droplets’ size, the present study focuses on the influence of the Bond number. This dimensionless number measures the influence of body forces compared with surface tension, which usually drives the Rayleigh-Plateau instability. The present work uses numerical simulation to assess the influence of the Bond number on both main droplets and satellites issuing from the Rayleigh-Plateau instability jet.

  15. Comprehensive geophysics and lithosphenc structure in the western Xizang (Tibet) Plateau

    Institute of Scientific and Technical Information of China (English)

    孔祥儒; 王谦身; 熊绍柏

    1996-01-01

    Comprehensive investigations along the Gyirong-Lugu-Sangehu geophysical profile in the western Xizang Plateau are presented. Analysis and interpretation of the lithospheric structure resulted in setting up of the geophysical methods and marks for the division of tectonic units in the lithospheric structure. Comprehensive geophysical survey in the remote west of Xizang is reported and some reliable geophysical evidence for deep structure division in the study region is provided. These lay a solid basis for probing into the mechanism of the Xizang Plateau uplift and geodynamics.

  16. Variation Characteristics of Sunshine Hours and Its Reason Analysis over Loess Plateau of Shaanxi

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The research aimed to study variation characteristics of sunshine hours over Loess Plateau of Shaanxi during 1961-2010.[Method] By using the climate tendency rate,climate trend coefficient and linear correlation,the temporal and spatial variation characteristics of sunshine hours in Loess Plateau of Shaanxi in recent 50 years were analyzed.Moreover,the main reason for inducing variation of sunshine hours in the zone was discussed.[Result] In recent 50 years,the variation of annual sunshine hours...

  17. Pseudoarthrosis of medial tibial plateau fracture——role of alignment procedure

    Institute of Scientific and Technical Information of China (English)

    Ashish Devgan; Pradeep Kamboj; Vinay Gupta; Narender K Magu; Rajesh Rohilla

    2013-01-01

    Nonunion in tibial plateau fractures is very rare.Limited literature is available on Pubmed search on intraarticular tibial nonunion.Most of the cases reported have been following failed surgical treatment and none was neglected fractures.Three patients of isolated and neglected medial tibial plateau nonunion with almost similar demographic profile are reported in this paper.All the three patients were managed by minimally invasive compression fixation using lag screws supplemented with limb realignme nt procedure of high tibial osteotomy.We discussed theinjury mechanism,management and rehabilitation in such cases and reviewed the available literature regarding such a presentation.

  18. Ornithological monitoring of the wind farms of the Garrigue high plateau (Aude); Suivi ornithologique des parcs eoliens du Plateau de Garrigue Haute (Aude)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This document presents the monitoring of the premarital migration 2001 in the wind farm of Corbieres-Maritime on the Garrigue Haute plateau. It aims to study the wind turbines impacts and risks on the migration. In spite of a weak mortality, the number of observed modifications in the birds habits at the approach of the wind turbines confirms the necessity of taking into account the migration phenomena in the wind farms projects. (A.L.B.)

  19. [Study of blood oxygen saturation, heart rate changes and plateau reaction of the Antarctic Kunlun station investigation team in different plateau environments].

    Science.gov (United States)

    Zhao, Shun-yun; Wu, Xin-min; Guo, Ya-min; Zhang, Shu-shun; An, Yan-ming; Li, Bing; Wang, Hao

    2013-06-11

    To explore the blood oxygen saturation and heart rate changes of the Antarctic explorers. During August 2010 to April 2011, the changes in blood oxygen saturation, heart rate and plateau reaction of 16 Antarctic expedition team in different plateau environments (Tibetan plateau versus Antarctic plateau) were monitored with the noninvasive pulse oximeter MD300-C. The extent of acute mountain sickness was determined according to the Lake Louise Consensus acute mountain reaction symptom scores and judgment method. The changes of blood oxygen saturation, heart rate at different altitudes of 110, 3650, 4300 m (96.8% ± 1.2%,89.1% ± 1.2%, 86.1% ± 2.0%, (75.0 ± 5.4) times/min, (104.0 ± 4.3) times/min, (113.0 ± 5.2) times/min,F = 214.155, 240.088,both P blood oxygen saturation, heart rate at different altitudes of 2000, 2500, 3000, 3500 and 4087 m(91.9% ± 1.3%,90.5% ± 1.3%,87.6% ± 1.4%,85.0% ± 1.8%,81.5% ± 2.2%, (85.9 ± 3.2) times/min, (90.6 ± 2.8) times/min, (97.8 ± 4.1) times/min, (102.0 ± 3.4) times/min, (106.3 ± 3.9) times/min, F = 105.418, 90.174, both P blood oxygen saturation and heart rate were both correlated with the risk of altitude sickness (r = -0.446 and 0.565, both P heart rate of the Antarctic explorers. And with the increases of altitude, the risk of altitude sickness gradually increases.

  20. δ18O record and temperature change over the past 100 years in ice cores on the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    YAO; Tandong; GUO; Xuejun; Lonnie; Thompson; DUAN; Keqin; WANG; Ninglian; PU; Jianchen; XU; Baiqing; YANG; Xiaoxin; SUN; Weizhen

    2006-01-01

    The 213 m ice core from the Puruogangri Ice Field on the Tibetan Plateau facilitates the study of the regional temperature changes with its δ18O record of the past 100 years. Here we combine information from this core with that from the Dasuopu ice core (from the southern Tibetan Plateau), the Guliya ice core (from the northwestern Plateau) and the Dunde ice core (from the northeastern Plateau) to learn about the regional differences in temperature change across the Tibetan Plateau. The δ18O changes vary with region on the Plateau, the variations being especially large between South and North and between East and West. Moreover, these four ice cores present increasing δ18O trends, indicating warming on the Tibetan Plateau over the past 100 years. A comparative study of Northern Hemisphere (NH) temperature changes, the δ18O-reflected temperature changes on the Plateau, and available meteorological records show consistent trends in overall warming during the past 100 years.

  1. Breaking the spiral of unsustainability : an exploratory land use study for Ansai, the Loess Plateau of China

    NARCIS (Netherlands)

    Lu, C.

    2000-01-01

    Serious soil loss, food insecurity, population pressure, and low income of the rural population are interrelated, and consequently result in a spiral of unsustainability in the Loess Plateau, China. This thesis takes Ansai County in the Loess Plateau of China as a case study, to explore str

  2. Breaking the spiral of unsustainability : An exploratory Land use study for Ansai, the Loess Plateau of China

    NARCIS (Netherlands)

    Lu Changhe,

    2000-01-01

    Serious soil loss, food insecurity, population pressure, and low income of the rural population are interrelated, and consequently result in a spiral of unsustainability in the Loess Plateau, China. This thesis takes Ansai County in the Loess Plateau of China as a case study, to explore strategic la

  3. A study of cloud microphysics and precipitation over the Tibetan Plateau by radar observations and cloud-resolving model simulations: Cloud Microphysics over Tibetan Plateau

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Wenhua [State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing China; Pacific Northwest National Laboratory, Richland Washington USA; Sui, Chung-Hsiung [Department of Atmospheric Sciences, National Taiwan University, Taipei Taiwan; Fan, Jiwen [Pacific Northwest National Laboratory, Richland Washington USA; Hu, Zhiqun [State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing China; Zhong, Lingzhi [State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing China

    2016-11-27

    Cloud microphysical properties and precipitation over the Tibetan Plateau (TP) are unique because of the high terrains, clean atmosphere, and sufficient water vapor. With dual-polarization precipitation radar and cloud radar measurements during the Third Tibetan Plateau Atmospheric Scientific Experiment (TIPEX-III), the simulated microphysics and precipitation by the Weather Research and Forecasting model (WRF) with the Chinese Academy of Meteorological Sciences (CAMS) microphysics and other microphysical schemes are investigated through a typical plateau rainfall event on 22 July 2014. Results show that the WRF-CAMS simulation reasonably reproduces the spatial distribution of 24-h accumulated precipitation, but has limitations in simulating time evolution of precipitation rates. The model-calculated polarimetric radar variables have biases as well, suggesting bias in modeled hydrometeor types. The raindrop sizes in convective region are larger than those in stratiform region indicated by the small intercept of raindrop size distribution in the former. The sensitivity experiments show that precipitation processes are sensitive to the changes of warm rain processes in condensation and nucleated droplet size (but less sensitive to evaporation process). Increasing droplet condensation produces the best area-averaged rain rate during weak convection period compared with the observation, suggesting a considerable bias in thermodynamics in the baseline simulation. Increasing the initial cloud droplet size causes the rain rate reduced by half, an opposite effect to that of increasing droplet condensation.

  4. Dust emissions from unpaved roads on the Colorado Plateau

    Science.gov (United States)

    Duniway, M.; Flagg, C.; Belnap, J.

    2013-12-01

    On the Colorado Plateau, elevated levels of aeolian dust have become a major land management and policy concern due to its influence on climate, weather, terrestrial ecosystem dynamics, landscape development and fertility, melting of snow and ice, air quality, and human health. Most desert soil surfaces are stabilized by plants, rocks, and/or physical or biological soil crusts, but once disturbed, sediment production from these surfaces can increase dramatically. Road development and use is a common surface disturbing activity in the region. The extent and density of roads and road networks is rapidly increasing due to continued energy exploration, infrastructure development, and off-highway recreation activities. Though it is well known that unpaved roads produce dust, the relative contribution of dust from existing roads or the implications of future road development to regional dust loading is unknown. To address this need, we have initiated a multifaceted research effort to evaluating dust emissions from unpaved roads regionally. At 34 sites arranged across various road surfaces and soil textures in southeastern Utah, we are: 1) monitoring dust emissions, local wind conditions, and vehicle traffic and 2) evaluating fugitive dust potential using a portable wind tunnel and measuring road characteristics that affect dust production. We will then 3) develop a GIS-based model that integrates results from 1 & 2 to estimate potential dust contributions from current and future scenarios of regional road development. Passive, horizontal sediment traps were installed at three distances downwind from the road edge. One control trap was placed upwind of the samplers to account for local, non-road dust emissions. An electronic vehicle counter and anemometer were also installed at monitoring sites. Dust samples were collected every three months at fixed heights, 15 cm up to 100 cm above the soil surface, from March 2010 to the present. Threshold friction velocities (TFV

  5. Summary of the mineralogy of the Colorado Plateau uranium ores

    Science.gov (United States)

    Weeks, Alice D.; Coleman, Robert Griffin; Thompson, Mary E.

    1956-01-01

    In the Colorado Plateau uranium has been produced chiefly from very shallow mines in carnotite ores (oxidized vanadiferous uranium ores) until recent deeper mining penetrated black unoxidized ores in water-saturated rocks and extensive exploration has discovered many deposits of low to nonvanadiferous ores. The uranium ores include a wide range from highly vanadiferous and from as much as one percent to a trace of copper, and contain a small amount of iron and traces of lead, zinc, molybdenum, cobalt, nickel, silver, manganese, and other metals. Recent investigation indicates that the carnotite ores have been derived by progressive oxidation of primary (unoxidized) black ores that contain low-valent uranium and vanadium oxides and silicates. The uranium minerals, uraninite and coffinite, are associated with coalified wood or other carbonaceous material. The vanadium minerals, chiefly montroseite, roscoelite, and other vanadium silicates, occur in the interstices of the sandstone and in siltstone and clay pellets as well as associated with fossil wood. Calcite, dolomite, barite and minor amounts of sulfides, arsenides, and selenides occur in the unoxidized ore. Partially oxidized vanadiferous ore is blue black, purplish brown, or greenish black in contrast to the black or dark gray unoxidized ore. Vanadium combines with uranium to form rauvite. The excess vanadium is present in corvusite, fernandinite, melanovanadite and many other quadrivalent and quinquevalent vanadium minerals as well as in vanadium silicates. Pyrite and part or all of the calcite are replaced by iron oxides and gypsum. In oxidized vanadiferous uranium ores the uranium is fixed in the relatively insoluble minerals carnotite and tyuyamunite, and the excess vanadium commonly combines with one or more of the following: calcium, sodium, potassium, magnesium, aluminum, iron, copper, manganese, or barium, or rarely it forms the hydrated pentoxide. The relatively stable vanadium silicates are little

  6. Carbon fluxes of Kobresia pygmaea pastures on the Tibetan Plateau

    Science.gov (United States)

    Babel, Wolfgang; Biermann, Tobias; Falge, Eva; Ingrisch, Johannes; Leonbacher, Jürgen; Schleuss, Per; Kuzyakov, Yakov; Ma, Yaoming; Miehe, Georg; Foken, Thomas

    2014-05-01

    With an approximate cover of 450,000 km² on the Tibetan Plateau (TP), the Cyperaceae Kobresia pygmaea forms he world's largest alpine ecosystem. This species, especially adapted to grazing pressure, grows to a height of only 2-6 cm and can be found in an altitudinal range of 4000 to 5960 m a.s.l. A special characteristic of this ecosystem is the stable turf layer, which is built up from roots and plays a significant role in protecting soil from erosion. This is of great importance since soils on the TP store 2.5 % of the global soil organic carbon stocks. The aim of the investigation was the study of the carbon storage and the impact of human-induced land use change on these Kobresia pygmaea pastures. We therefore applied eddy-covariance measurements and modelling as a long-term control of the fluxes between the atmosphere and the pastures and 13C labelling for the investigation of flux partitioning, and chamber measurements to investigate the degradation of the pastures. Combining CO2 budgets observed in 2010 with eddy-covariance measurements and relative partitioning of carbon fluxes estimated with 13C labelling enabled us to characterise the C turnover for the vegetation period with absolute fluxes within the plant-soil-atmosphere continuum. These results revealed that this ecosystem indeed stores a great amount of C in below-ground pools, especially in the root turf layer. To further investigate the importance of the root layer, the experiments in 2012 focused on flux measurements over the different surface types which make up the heterogeneity of the Kobresia pygmaea pastures and might result from degradation due to extensive grazing. The three surface types investigated with a LiCOR long-term monitoring chamber system include Kobresia pygmaea with intact turf layer (IRM), a surface type where the turf layer is still present but the vegetation is sparse and mainly consists of Cryptogam crusts (DRM) and finally areas without the turf layer (BS). According to

  7. Intraoperative study on anthropometry and gender differences of the proximal tibial plateau at the arthroplasty resection surface

    Institute of Scientific and Technical Information of China (English)

    Yang Bo; Yu Jiakuo; Gong Xi; Chen Lianxu; Wang Yongjian; Wang Jian; Wang Haijun

    2014-01-01

    Background The tibial plateau is asymmetric with a larger medial plateau.We observed from clinical practice that the shape of the tibial plateau does not always present a larger medial plateau.Tibial plateau also showed other shapes.The purpose of this study was to analyze the anthropometric data of the proximal tibia in a large group of Chinese patients undergoing total knee arthroplasty and to investigate the morphology of the resected proximal tibial surface and its gender differences.Methods A total of 822 knees (164 males,658 females) from the Chinese population were measured intraoperatively for medial anteroposterior (MAP) and lateral anteroposterior (LAP) dimensions of the resected proximal tibial surface.The difference of MAP and LAP (DML) was also calculated as MAP minus LAP.We then classified the data into three groups based on the DML (<-2,-2 to 2,and >2 mm) to analyze the morphology of the proximal tibia and its distribution between male and female.Results The shape of proximal tibial plateau was of three types:larger medial plateau type,symmetric type,and larger lateral plateau type.There were significant differences between males and females in relation to the shape distribution of the proximal tibial plateau (P <0.05).Most of the proximal tibial plateau was asymmetric,with 517 of 822 (62.9%) tibia having a DML >2 mm and 120 of 822 (14.6%) tibia having a DML<-2 mm.Only 185 of 822 (22.5%) tibia had a DML between-2 and 2 mm.Conclusion The results of this study can be used as a guideline to design tibial components with different DMLs to better match the different anthropometry of the resected tibial surface.

  8. Cenozoic exhumation of the internal Zagros : First constraints from low-temperature thermochronology and implications for the build-up of the Iranian plateau

    NARCIS (Netherlands)

    François, T.; Agard, P.; Bernet, M.; Meyer, B.; Chung, S.-L.; Zarrinkoub, M. H.; Burov, E.; Monié, P.

    2014-01-01

    The Iranian plateau is a flat ~. 1.5-2. km high plateau thought to result from the collision between the Arabian and Eurasian plates since ~. 30 ± 5. Ma, and may represent a young analogue to the so far better studied Tibetan plateau. In order to constrain the exhumation history of the internal Zagr

  9. Seismic imaging of a mid-lithospheric discontinuity beneath Ontong Java Plateau

    Science.gov (United States)

    Tharimena, Saikiran; Rychert, Catherine A.; Harmon, Nicholas

    2016-09-01

    Ontong Java Plateau (OJP) is a huge, completely submerged volcanic edifice that is hypothesized to have formed during large plume melting events ∼90 and 120 My ago. It is currently resisting subduction into the North Solomon trench. The size and buoyancy of the plateau along with its history of plume melting and current interaction with a subduction zone are all similar to the characteristics and hypothesized mechanisms of continent formation. However, the plateau is remote, and enigmatic, and its proto-continent potential is debated. We use SS precursors to image seismic discontinuity structure beneath Ontong Java Plateau. We image a velocity increase with depth at 28 ± 4 km consistent with the Moho. In addition, we image velocity decreases at 80 ± 5 km and 282 ± 7 km depth. Discontinuities at 60-100 km depth are frequently observed both beneath the oceans and the continents. However, the discontinuity at 282 km is anomalous in comparison to surrounding oceanic regions; in the context of previous results it may suggest a thick viscous root beneath OJP. If such a root exists, then the discontinuity at 80 km bears some similarity to the mid-lithospheric discontinuities (MLDs) observed beneath continents. One possibility is that plume melting events, similar to that which formed OJP, may cause discontinuities in the MLD depth range. Plume-plate interaction could be a mechanism for MLD formation in some continents in the Archean prior to the onset of subduction.

  10. Survey reveals floral emission of methane on Qinghai-Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    @@ Along-term field observation by CAS scientists indicates that meadows on the Qinghai-Tibet Plateau emit methane,a powerful greenhouse gas, adding weight to the argument that the living plant is a producer of methane under aerobic conditions.

  11. Survey reveals floral emission of methane on Qinghai-Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ A long-term field observation by CAS scientists indicates that meadows on the Qinghai-Tibet Plateau emit methane,a powerful greenhouse gas,adding weight to the argument that the living plant is a producer of methane under aerobic conditions.

  12. Crustal Flows beneath the Eastern Tibetan Plateau Revealed by Magnetotelluric Observations

    Institute of Scientific and Technical Information of China (English)

    BAI Dengha; TENG Jiwen; MA Xiaobing; KONG Xiangru

    2011-01-01

    The ongoing collision of the Indian and Asian continents has created the Himalayan and Tibetan plateau through a range of deformation processes that include crustal thickening, delamination, lateral extrusion and crustal flow. A debate continues as to which of these processes are most significant in terms of the overall mass balance of this continent-continent collision.

  13. Relation between stable isotope in monsoon precipitation in southern Tibetan Plateau and moisture transport history

    Institute of Scientific and Technical Information of China (English)

    田立德; 姚檀栋; A.Numaguti; 段克勤

    2001-01-01

    The moisture transport history to the south of the Tibetan Plateau was modeled using the meteorological data provided by NCEP in this paper, and the modeled results were compared with the measured δ18O in the south of the Tibetan Plateau. The relation between δ18O in precipitation in the south of the Tibetan Plateau and moisture trajectories was discussed. The results show that the extremely low δ18O in precipitation in the south of the Tibetan Plateau is always related to the moisture from the low-level sea surface evaporation. The long-distance transport of moisture also contributes to low δ18O in precipitation probably due to the rainout process during moisture transport. It is also found that lowδ18O in precipitation is also related with deep layer transport of moisture, and with intensive condensation in the upper layers of the atmosphere, resulting in low δ18O because of depletion of heavy isotopes in deep condensation. However, high δ18O in precipitation whether in monsoon period or not is

  14. A trade-off analysis of policy objectives for Ansai, the Loess Plateau of China

    NARCIS (Netherlands)

    Lu, C.H.; Ittersum, van M.K.

    2004-01-01

    Ansai is a county characterized by hilly loess relief that experiences all problems typical to the Loess Plateau of northern China, such as population pressure, soil loss, over-use of marginal lands, and poverty and food insecurity problems. Alleviation of these problems needs an integrated consider

  15. Inorganic pollution around the Qinghai-Tibet Plateau: An overview of the current observations.

    Science.gov (United States)

    Wu, Jun; Duan, Dongping; Lu, Jian; Luo, Yongming; Wen, Xiaohu; Guo, Xiaoying; Boman, Brian J

    2016-04-15

    The Qinghai-Tibet Plateau is the highest geographical unit in the world. Thus, it serves an important role in evaluating long-term ecologic conditions and environmental status and changes over time. This study summarizes major and trace element concentrations in biota and in water and soil. It also pays attention to gaseous pollutant and particle concentrations in air around the Qinghai-Tibet Plateau. The degree of soil heavy metal contamination and the water heavy metal hazard index were respectively evaluated. The contamination degrees of two sampling areas around the Qinghai-Tibet Plateau reached extremely high levels with soil mCd (modified degree of contamination) values exceeding 20. Surprisingly, over 54% of sampling areas showed moderate or more serious soil contamination degree (mCd>1.5). Moreover, the hazard indexes of two important rivers were 1.56 and 7.59, reaching unacceptable level. The potential risk might be beyond our expectation. Therefore, it should be an urgent and top priority to identify and confirm possible pollution sources around the Qinghai-Tibet Plateau. Then, it is imperative to implement feasible and effective environmental quality control strategies.

  16. Thermal adaptation of the large-scale circulation to the summer heating over the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The potential vorticity equation is employed to diagnose the variation in the large-scale atmospheric circulation in July by using the NCAR/NCEP daily reanalysis data from 1986 to 1995. Based on the theogy of thermal adaptation, the schematic diagram of the formation and maintenance of the circulation over the Tibetan Plateau is revealed in this paper. The result shows that near the surface of ground is the positive potential vorticity source produced by the increasing diabatic heating with height, which maintains the cyclonic circulation, and that the positive Ertel potential vorticitv (PV) source is balanced by friction dissipation. On the other hand, in the upper troposphere the negative PV produced by the decreasing diabatic heating with height maintains the anticyclone, and it is balanced by the divergence of the negative PV. The Gauss' theorem has been applied to analyze the Ertel potential vorticity flux crossing each of the lateral boundaries of the area over the Tibetan Plateau. The result shows that the negative PV flux is transferred through the eastern and northern boundaries of the area from the Tibetan Plateau region to the outer world. It is evident that the Tibetan Plateau region is an important source of negative vorticity of the atmosphere.

  17. Prehistoric Human Dispersal to the Tibetan Plateau and Adaptation to the High Altitude Environment

    Science.gov (United States)

    Zhang, Dongju; Dong, Guanghui; Chen, Fahu

    2016-04-01

    Human history of the Tibetan Plateau and human adaptation to the high altitude environment is hotly debated in the past decade among archaeological, anthropological, genetic, and even past climate change studies. Based on previous studies on the Tibetan Plateau and our own archaeological studies in northeastern Tibetan Plateau (NETP), we propose that human migrated to the Tibetan Plateau from the last Deglacial period to late Holocene mainly from North China via Yellow River valley and its tributary valleys in NETP. This migration is constituted of four stages (Upper Paleolithic, Epi-Paleolithic, Neolithic and Bronze Age) when human adapted to the high altitude environment and climate change with different strategies and techniques. Particularly, the prevail of microlithic technology in North China provoked hunter-gatherers' first visit to the NETP in relatively ameliorated last Deglacial period, and the quick development of millet farming and subsequent mixed barley-wheat farming and sheep herding facilitated farmers and herders permanently settled in NETP, even above 3000 masl, during mid- and late Holocene.

  18. Recent dynamics of alpine lakes on the endorheic Changtang Plateau from multi-mission satellite data

    Science.gov (United States)

    Yang, Kehan; Yao, Fangfang; Wang, Jida; Luo, Jiancheng; Shen, Zhanfeng; Wang, Chao; Song, Chunqiao

    2017-09-01

    Monitoring of the alpine lakes on the endorheic Changtang Plateau is vitally important in understanding climate impacts on hydrological cycle. Existing studies have revealed an accelerated lake expansion on the Changtang Plateau during the 2000s compared with prior decades. However, the partial hiatus of recent Landsat archive affected the continuation of understanding the lake changes in the recent decade. Here we synergistically used imagery from Landsat and Huanjing satellites to enable a detailed monitoring of lake area dynamics on the Changtang Plateau. Our results present that lakes on the Changtang Plateau continued to expand at a rapid rate of 340.79 km2 yr-1 (1.06% yr-1, p variations of the selected 24 large lakes fluctuated within 0.22-2.46% (in coefficient of variation) for glacier-fed lakes and 0.17-2.36% for non-glacier-fed lakes. Most of these lakes expanded during the unfrozen period (from May/June to October) and reached to their maximum extents in September or October. By spatially associating our revealed lake changes with climate variables, we observed that the recent lake expansion is more related to precipitation than to temperature, although future efforts are needed for a more comprehensive picture of the lake changing mechanisms.

  19. The Plant Foliage Projective Coverage Change over the Northern Tibetan Plateau during 1957-2009

    Science.gov (United States)

    Cuo, L.

    2015-12-01

    Northern Tibetan Plateau is the headwater of the Yellow River, the Yangtze River and the Mekong River that support billions of the population. Vegetation change will affect the regional ecosystem and water balances through the changes in biomass and evapotranspiration. Dynamic vegetation growth is determined by physiological, morphological, bioclimatic and phenological properties. These properties are affected by climate variables such as air temperature, precipitation, soil temperature and concentration of CO2, etc. Due to climate change, some parts of the northern Tibetan Plateau are under the threat of desertification. Identifying the places of vegetation degradation and the dominant driven climatic factors will help mitigate the climate change impacts on ecosystem and water resources in this region. In this study, the changes of foliage projective coverages (FPCs) of various plant functional types (PFTs) existed in the northern Tibetan Plateau and the responses of FPCs to the four climate variables over 1957-2009 are examined. The dominant factors among the four climate variables are also identified. The Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ-DGVM) is modified and used for the investigation. The modified LPJ-DGVM can better account for soil temperature in the top 0.4-m depth where vegetation root concentrates over the northern Tibetan Plateau. The modified model is evaluated by using monthly and annual soil temperature observed at stations across the region, and the eco-geographic maps that describe plant types and spatial distributions developed from field surveys and satellite images for this region.

  20. Characterizing the dynamics of soil organic carbon in grasslands on the Qinghai-Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Carbon dynamics of grasslands on the Qinghai-Tibetan Plateau may play an important role in regional and global carbon cycles. The CENTURY model (Version 4.5) is used to examine temporal and spatial variations of soil organic carbon (SOC) in grasslands on the Plateau for the period from 1960 to 2002. The model successfully simulates the dynamics of aboveground carbon and soil surface SOC at the soil depth of 0-20 cm and the simulated results agree well to the measurements. Examination of SOC for eight typical grasslands shows different patterns of temporal variation in different ecosystems in 1960-2002. The extent of temporal variation increases with the increase of SOC of ecosystem. SOC increases first and decreases quickly then during the period from 1990 to 2000. Spatially, SOC density obtained for the equilibrium condition declines gradually from the southeast to the northwest on the plateau and showed a high heterogeneity in the eastern plateau. The results suggest that (i) SOC den-sity in the alpine grasslands shows remarkable response to climate change during the 42 years, and (ii) the net carbon exchange rate between the alpine grassland ecosystems and the atmosphere increases from 1990 to 2000 as compared with that before 1990.

  1. Characterizing the dynamics of soil organic carbon in grasslands on the Qinghai-Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    ZHANG YongQiang; TANG YanHong; JIANG Jie; YANG YongHui

    2007-01-01

    Carbon dynamics of grasslands on the Qinghai-Tibetan Plateau may play an important role in regional and global carbon cycles. The CENTURY model (Version 4.5) is used to examine temporal and spatial variations of soil organic carbon (SOC) in grasslands on the Plateau for the period from 1960 to 2002. The model successfully simulates the dynamics of aboveground carbon and soil surface SOC at the soil depth of 0-20 cm and the simulated results agree well to the measurements. Examination of SOC for eight typical grasslands shows different patterns of temporal variation in different ecosystems in 1960-2002. The extent of temporal variation increases with the increase of SOC of ecosystem. SOC increases first and decreases quickly then during the period from 1990 to 2000. Spatially, SOC density obtained for the equilibrium condition declines gradually from the southeast to the northwest on the plateau and showed a high heterogeneity in the eastern plateau. The results suggest that (i) SOC density in the alpine grasslands shows remarkable response to climate change during the 42 years, and (ii) the net carbon exchange rate between the alpine grassland ecosystems and the atmosphere increases from 1990 to 2000 as compared with that before 1990.

  2. Energy and water cycle over the Tibetan plateau : surface energy balance and turbulent heat fluxes

    NARCIS (Netherlands)

    Su, Zhongbo; Zhang, Ting; Ma, Yaoming; Jia, Li; Wen, Jun

    2006-01-01

    This contribution presents an overview and an outlook of studies on energy and water cycle over the Tibetan plateau with focuses on the estimation of energy balance terms and turbulent heat fluxes. On the basis of the surface energy balance calculations, we show that the phenomena of the energy imba

  3. Energy and water cycle over the Tibetan Plateau: surface energy balance and turbulent heat fluxes

    NARCIS (Netherlands)

    Su, Z.; Zhang, T.; Ma, Y.; Jia, L.; Wen, J.

    2006-01-01

    This contribution presents an overview and an outlook of studies on energy and water cycle over the Tibetan plateau with focuses on the estimation of energy balance terms and turbulent heat fluxes. On the basis of the surface energy balance calculations, we show that the phenomena of the energy imba

  4. On measuring and remote sensing surface energy partitioning over the Tibetan Plateau

    NARCIS (Netherlands)

    Ma, Y.; Su, Z.; Koike, T.; Yao, T.; Ishikawa, H.; Ueno, K.; Menenti, M.

    2003-01-01

    The energy and water cycle over the Tibetan Plateau play an important role in the Asian monsoon system, which in turn is a major component of both the energy and water cycles of the global climate system. The intensive observation period and long-term observation of the GEWEX (global energy and wate

  5. The property, age and formation environment of the palaeokarst in Qinghai-Xizang Plateau

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The karst landforms distributed on the Qinghai-Xizang (Tibet) Plateau can be genetically classed with the Tertiary underground karst, which were gradually exhumed to the surface with the uplift of the plateau during Quaternary period. The relative deposits of the Tertiary palaeokarst processes, such as the residuum and speleothem, were discovered recently in the southern and southeastern fringe areas of the plateau, where has geological-currently been disintegrated by the headward erosion processes of the modern river systems. The major chemical components of the clay portion of the residuum consist mainly of SiO2, Al2O3 and Fe2O3. The clay minerals composition of the clay portion belongs to illite-kaolinite pattern for most of the residuum samples, and kaoliniteillite pattern for a few of the samples. It can be judged from the silicic acid index and the clay minerals composition that the formation of the residuum of the Plateau was in its initial phase.However, such a lower chemical weathering index only reflected the weathering degree in the bottom or lower parts of the lateritic weathering crust. The relatively intensive chemical weathering processes of the surface layers of the lateritic weathering crust could be logically speculated. The surface feature textures of quartz grains in the residuum were formed mainly by the chemical erosion, which revealed a long-term humid-tropical environment when the residuum and the palaeokarst formed.

  6. Discharge and sediment measurements at the outlet of a watershed on the Loess plateau of China

    NARCIS (Netherlands)

    Elsen, van den H.G.M.; Hessel, R.; Liu Baoyuan,; Trouwborst, K.O.; Stolte, J.; Ritsema, C.J.; Blijenberg, H.

    2003-01-01

    A dam and weir system was constructed to measure the discharge of water and sediment from a selected small catchment on the Loess plateau in China. The aim of the system described here was to collect data on discharge and sediment content during occasional summer storms. These data can be used for c

  7. Ptilagrostis contracta (Stipeae, Poaceae), a New Species Endemic to Qinghai-Tibet Plateau.

    Science.gov (United States)

    Zhang, Zhong-Shuai; Li, Ling-Lu; Chen, Wen-Li

    2017-01-01

    A new species, Ptilagrostis contracta, endemic to Qinghai-Tibet Plateau is described and illustrated. It is distinguished from other species in Ptilagrostis by having contracted panicles, 1-geniculate awns with hairy columns and scabrous bristles and evenly pubescent lemmas. Evidence from lemma epidermal pattern, cytology and molecular phylogenetic analyses based on the nuclear ITS sequence data confirm its systematic position in Ptilagrostis.

  8. Development of regeneration following gypsy moth defoliation of Appalachian Plateau and Ridge & Valley hardwood stands

    Science.gov (United States)

    D.M. Hix; D.E. Fosbroke; R.R., Jr. Hicks; K.W. Gottschalk

    1991-01-01

    The effects of gypsy moth defoliation and subsequent overstory mortality on regeneration were located in the Appalachian Plateau physiographic province, and the Maryland stands were located in the Ridge & Valley province. Pre-defoliation data (1984-1986) were compared with post-defoliation data (1989) from the same 315 six-foot-radius plots.

  9. Inert tracer gas washout from mixed venous blood: the sloping alveolar plateau

    NARCIS (Netherlands)

    Vries, W.R. de; Luijendijk, S.C.M.; Zwart, Aart

    1982-01-01

    The aim of this model study was to investigate the mechanisms underlying the sloping alveolar plateau for inert tracer gases supplied to the lung by mixed venous blood. Transpulmonary gas exchange was simulated in an asymmetric lung model for conditions at rest and in exercise. For highly soluble ga

  10. Market perceptions and opportunities for native plant production on the southern Colorado Plateau

    Science.gov (United States)

    Donna L. Peppin; Peter Z. Fule; Janet C. Lynn; Anne L. Mottek-Lucas; Carolyn Hull Sieg

    2010-01-01

    Increases in revegetation activities have created a large demand for locally adapted native plant materials (NPM) in the southwestern United States. Currently, there is a minimal supply of local genotypes to meet this demand. We investigated the potential for the initiation of a native plant market in the southern Colorado Plateau. Through a literature search,...

  11. Variational features of precipitation δ18O in Northeast Qinghai-Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    章新平; 施雅风; 姚檀栋

    1995-01-01

    There is a marked positive correlation between δ18O in atmospheric precipitation andtemperature in the Northeast Qinghai-Tihet Plateau.The amount effect in Tuotuohe station is notable as thetemperature is greater than or equal to 7.3℃,so is in Xining as 8.3℃.The analytic results show that thesynoptic and climatic significance of different time scales is different,and their degrees are also different.Moreover,the relations between the weather systems in the Northeast Qinghai-Tibet Plateau and δ18O inprecipitation are analyzed.Under the influence of continental air mass the δ18O change in the Plateau issynchronous with that of temperature and under the oceanic air mass originated from the Bengal Bay and theArabian Sea there is a marked negative correlation between δ18O and precipitation amount or temperature in themonsoon region of the Plateau and also positive one between δ18O and temperature in the non-monsoon region.

  12. Relationship Between the Eastern Tibetan Plateau Rainfall and Subtropical High Shift in Summer

    Institute of Scientific and Technical Information of China (English)

    GONG Yuanfa; HE Jinhai; CHEN Longxun

    2006-01-01

    Based on the routine rainfall data on the Tibetan Plateau and NCEP/NCAR reanalysis data, the rela tionship between the eastern Tibetan Plateau rainfall and the southward/northward shift of West Pacific subtropical high in summer of 1993/1994 is studied. The results show that: the West Pacific subtropi cal high is abnormally located to more southern latitude and the high ridge is mainly the quasi-biweekly southward/northward oscillation in its processes of northward shift from May to August in 1993; but it is ab normally located to more northern latitude and the high ridge is obviously 30-60-day southward/northward oscillation in its processes of northward shift from May to August in 1994. At the same time, it is found that the changes of the eastern Tibetan Plateau rainfall active/break have the similar characteristics of the high ridge southward/northward oscillation. Therefore, the southward/northward shift of the West Pacific subtropical high in summer may be related to the changes of eastern Tibetan Plateau rainfall active/break.

  13. Consequences of hyperconcentrated flow for process-based soil erosion modelling on the Chinese Loess Plateau

    NARCIS (Netherlands)

    Hessel, R.

    2006-01-01

    High sediment concentrations in runoff are a characteristic feature of the Chinese Loess Plateau, and are probably caused by factors such as the occurrence of erodible materials on steep slopes, the characteristics of the loess and the harsh climate that results in low plant cover. When sediment con

  14. An off-line simulation of land surface processes over the northern Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    MinHong Song; YaoMing Ma; Yu Zhang; WeiQiang Ma; SiQiong Luo

    2014-01-01

    In order to further understand the land surface processes over the northern Tibetan Plateau, this study produced an off-line simulated examination at the Bujiao site on the northern Tibetan Plateau from June 2002 to April 2004, using the Noah Land Surface Model (Noah LSM) and observed data from the CAMP/Tibet experiment. The observed data were neces-sarily corrected and the number of soil layers in the Noah LSM was changed from 4 to 10 to enable this off-line simulation and analysis. The main conclusions are as follows:the Noah LSM performed well on the northern Tibetan Plateau. The simulated net radiation, upward longwave radiation, and upward shortwave radiation demonstrated the same remarkable annual and seasonal variation as the observed data, especially the upward longwave radiation. The simulated soil tem-peratures were acceptably close to the observed temperatures, especially in the shallow soil layers. The simulated freezing and melting processes were shown to start from the surface soil layer and spread down to the deep soil layers, but they took longer than the observed processes. However, Noah LSM did not adequately simulate the soil moisture. Therefore, addi-tional high-quality, long-term observations of land surface-atmosphere processes over the Tibetan Plateau will be a key factor in proper adjustments of the model parameters in the future.

  15. Revisiting land reform: land rights, access, and soil fertility management on the Adja Plateau in Benin

    NARCIS (Netherlands)

    Yemadje, H.R.M.; Crane, T.; Mongbo, R.L.; Saidou, A.; Azontond, H.A.; Kossou, D.K.; Kuyper, T.W.

    2014-01-01

    In the oil palm-based cropping system on the Adja Plateau, land titling plays an important role. Landowners argue that oil palm fallow (dekan) restores soil fertility, but in the long-term it is also an instrument in the struggle for control over land. A land-titling programme in the study area allo

  16. Magnetostratigraphy and palaeoclimate of Red Clay sequences from Chinese Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    孙东怀; 刘东生; 陈明扬; 安芷生; John Shaw

    1997-01-01

    Two Red Clay profiles near Xi’ an and Xifeng were investigated in an attempt to determine magne-tostratigraphic and palaeoclimatic records. The results show that aeolian dust accumulation and the related East Asia palaeomonsoon system had begun by 6.5 Ma, and it is deduced that the Tibetan Plateau had reached a significant elevation at that time. The late Tertiary palaeoclimatic history of the Red Clay as reflected by magnetic susceptibility is reconstructed during the period of 6.5-2.5 Ma. Stepwise increase in susceptibility of aeolian dust accumulation appears to have a close correlation to the uplift processes of the Tibetan Plateau. The remarkable increase of aeolian dust accumulation at 3.2 Ma appears to be due to the influence of global ice volume on the East Asia monsoon. Palaeomonsoon variation during the late Tertiary as recorded in the Red Clay sequences from the Chinese Loess Plateau can be regarded as the product of a number of interacting factors, such as uplift of the Tibetan Plateau, sola

  17. International Comparison and Implications of Agricultural Development in Foreign Low Latitude Plateau Regions for Yunnan Province

    Institute of Scientific and Technical Information of China (English)

    Yan; LUO; Yan; YANG; Rui; CHEN; Wei; WU; Ziyun; PENG; Liangzheng; CHEN; Xuelin; LI

    2013-01-01

    Climatic characteristics of foreign low latitude plateau regions are firstly introduced.Then,experience and lessons of major foreign low latitude plateau countries in developing modern agriculture are analyzed,including Indian three agricultural revolutions and agricultural informationization development,application of agricultural biotechnology in Brazil,trade liberalization and economic de-agriculture of Mexico,and Argentina,Saudi Arabia and South Africa attaching great importance to developing modern agriculture relying on science and technology and paying close attention to resource conservation and environmental protection.Combining natural and social resource characteristics of Yunnan plateau agriculture,pertinent implications and recommendations for modern agricultural development in Yunnan are put forward.Specifically,these include strengthening agricultural sci-tech research and development,and extension and application;transforming agricultural development model;enhancing agricultural resource conservation and environmental protection;accelerating developing mountain organic ecological agriculture and autumn agriculture;reinforcing urban and rural integration to develop plateau characteristic agriculture on the basis of local actual conditions.

  18. Effects of climatic gradients on genetic differentiation of Caragana on the Ordos Plateau, China

    Science.gov (United States)

    Jiuyan Yang; Samuel A. Cushman; Jie Yang; Mingbo Yang; Tiejun Bao

    2013-01-01

    The genus Caragana (Fabr.) in the Ordos Plateau of Inner Mongolia, China, provides a strong opportunity to investigate patterns of genetic differentiation along steep climatic gradients, and to identify the environmental factors most likely to be responsible for driving the radiation. This study used a factorial, multi-model approach to evaluate alternative hypotheses...

  19. Earth, Animals, and Academics: Plateau Indian Communities, Culture, and the Walla Walla Council of 1855.

    Science.gov (United States)

    Trafzer, Clifford E.

    1993-01-01

    Scholars analyzing events in American Indian history have the responsibility to consider not only the White political and social milieu but also American Indian world views, kinship ties, and political and spiritual influences. The Walla Walla Council of 1855, involving U.S. officials and Northwest Plateau tribes, illustrates the importance of…

  20. Mio-Pliocene morphotectonic evolution of the Iranian Plateau: from outward expansion to incision and excavation

    Science.gov (United States)

    Ballato, Paolo; Heidarzadeh, Ghasem; Zeilinger, Gerold; Ghassemi, Mohammad; Cifelli, Francesca; Mattei, Massimo; Hassanzadeh, Jamshid; Balling, Philipp; Dunkl, István; Sudo, Masafumi; Mulch, Andreas; Strecker, Manfred

    2015-04-01

    Located along plate convergence zones, high orogenic plateaus form extensive and elevated morphotectonic provinces that are flanked by high mountain ranges at their margins. The Iranian Plateau (IP) is a prominent NW-SE striking (ca. 1500 km in length for a width of 140 to 260 km), elevated (> 50% lies between 1.5 and 2 km of elevation), mostly internally drained (at present ca. 55% has internal drainage), arid (mean annual precipitation ranging from 0.1 to 50 km of distance) of conglomerates in the distal sectors of the basin. This event was followed by basin uplift and erosion with a shift of the basin depocenter toward the outer margin of the plateau (to the N and NE; Zanjan and Mianeh basins). There, sedimentation lasted until fluvial incision and basin excavation of sub-horizontal sediments started sometime during the last 4 Ma. Overall, our data suggest that sedimentation took place in a contiguous foreland-basin system, most likely triggered by thrust stacking and topographic loading in the interior of the plateau from ~17 Ma. The outward N to NE-directed propagation of the deformation fronts (< 10.5 Ma) excised parts of the foreland, incorporating new basin sectors into the orogenic plateau and compartmentalizing the foreland into a contractional basin and range topography. This implies that the IP developed during crustal shortening and thickening processes and that sometime after 10.5 Ma the northern IP had reached a lateral size similar to the modern one.

  1. A plateau in the sensitivity of a compact optically pumped atomic magnetometer

    Directory of Open Access Journals (Sweden)

    Natsuhiko Mizutani

    2014-05-01

    Full Text Available In a compact optically pumped atomic magnetometer (OPAM, there is a plateau in the sensitivity where the dependence of the sensitivity on pumping power is small compared with that predicted by the uniform polarization model. The mechanism that generates this plateau was explained by numerical analysis. The distribution of spin polarization in the alkali metal cell of an OPAM was modeled using the Bloch equation incorporating a diffusion term and an equation for the attenuation of the pump beam. The model was well-fitted to the experimental results for a module with a cubic cell with 20 mm sides and pump and probe beams with 8 mm diameter. On the plateau, strong magnetic response was generated at the regions that were not illuminated directly by the intense pump beam, while at the same time spin polarization as large as 0.5 was maintained due to diffusion of the spin-polarized atoms. Thus, the sensitivity of the magnetometer monitored with a probe beam decreases only slightly with increasing pump beam intensity because the spin polarization under an intense pump beam is saturated. This plateau, which is characteristic of this type of magnetometer using a narrow pump and probe beams, can be used in arrays of magnetometers because it enables stable operation with little sensitivity fluctuation from changes in pump beam power.

  2. Arthroscopically assisted treatment for Schatzker type I-V tibial plateau fractures

    Institute of Scientific and Technical Information of China (English)

    DUAN Xiao-jun; YANG Liu; GUO Lin; CHEN Guang-xing; DAI Gang

    2008-01-01

    Objective: To report the clinical outcome of arthroscopically assisted treatment for tibial plateau fractures.Methods: A total of 39 patients with tibial plateau fractures were treated by arthroscopic fixation from February 2002 to December 2005,including 11 patients with bony avulsion of the anterior cruciate ligament and 19 with meniscal injury.There were 4 cases of type I fracture,12 type II,9 type III,12 type IV and 2 type V according to Schatzker criteria.Firstly,the combined injuries were treated.Then the plateau fractures with the displacement over 3 mm or more were reduced and fixed.Finally,the internal fixation was observed by X-ray equipment.Postoperative management was early motion and delayed weight bearing.Results: All the fractures healed in 3 or 4 months.All patients were followed up for 1 to 5 years after operation.No case had severe complications,such as poor wound healing,infection,osteofascial compartment syndrome and osteoarthritis.According to the Rasmussen scoring system,36 cases obtained excellent or good results and the other 3 cases had moderate clinical results.The average score was 26 ± 3.Conclusions: As an adjuvant treatment of intraarticular fractures such as tibial plateau fracture,arthroscopy has many advantages.It can treat associated intraarticular soft tissue components,visualize the chondral surface reduction,lavage the hematoma and smaller loose fragments,decrease soft tissue dissection,reduce the risk of scarring and promote rapid recovery.

  3. [Coupling coordinated development of ecological-economic system in Loess Plateau].

    Science.gov (United States)

    Zhang, Qing-Feng; Wu, Fa-Qi; Wang, Li; Wang, Jian

    2011-06-01

    Based on system theory, a coupling coordinated development model of ecological-economic system in Loess Plateau was established, and the evaluation criteria and basic types of the coordinated development of the ecological-economic system were proposed. The county-level coupling coordinated development of the ecological-economic system was also discussed, based on the local characteristics. The interactions between the ecological and economic systems in Loess Plateau could be divided into four stages, i.e., seriously disordered development stage, mild-disordered development stage, low-level coordinated development stage, and high level well-coordinated development stage. At each stage, there existed a cyclic process of profit and loss-antagonist-running-dominant-synchronous development. The coupling development degree of the ecological-economic system in Loess Plateau was overall at a lower level, being about 62.7% of the counties at serious disorder, 30.1% of the counties at mild disorder, and 7.1% of the counties at low but coordinated level. The coupling development degree based on the model established in this study could better reflect the current social-economic and ecological environment situations, especially the status of coordination. To fully understand the coupling of ecological-economic system and to adopt appropriate development mode would be of significance to promote the county-level coordinated development in Loess Plateau.

  4. Abundance of color bands in Neogene carbonate sediments on Ontong Java Plateau:

    DEFF Research Database (Denmark)

    Berger, W.H.; Lind, Ida

    1997-01-01

    When comparing color-band abundances within one sediment section with those of others of the same age but deposited at different depths along a transect on the northeastern flank of Ontong Java Plateau in the western equatorial Pacific (ODP Leg 130), one notes that the sections with the highest s...

  5. Inert tracer gas washout from mixed venous blood: the sloping alveolar plateau

    NARCIS (Netherlands)

    Vries, W.R. de; Luijendijk, S.C.M.; Zwart, Aart

    1982-01-01

    The aim of this model study was to investigate the mechanisms underlying the sloping alveolar plateau for inert tracer gases supplied to the lung by mixed venous blood. Transpulmonary gas exchange was simulated in an asymmetric lung model for conditions at rest and in exercise. For highly soluble

  6. San Luis Valley - Taos Plateau Landscape-Level Cultural Heritage Values and Risk Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Wescott, Konstance L. [Argonne National Lab. (ANL), Argonne, IL (United States); Abplanalp, Jennifer M. [Argonne National Lab. (ANL), Argonne, IL (United States); Brown, Jeff [Bureau of Land Management, Monte Vista, CO (United States); Cantwell, Brian [Argonne National Lab. (ANL), Argonne, IL (United States); Dicks, Merrill [Bureau of Land Management, Taos, NM (United States); Fredericks, Brian [Bureau of Land Management, Monte Vista, CO (United States); Krall, Angie [US Forest Service, Creede, CO (United States); Rollins, Katherine E. [Argonne National Lab. (ANL), Argonne, IL (United States); Sullivan, Robert [Argonne National Lab. (ANL), Argonne, IL (United States); Valdez, Arnie [Univ. of New Mexico, Albuquerque, NM (United States); Verhaaren, Bruce [Argonne National Lab. (ANL), Argonne, IL (United States); Vieira, Joseph [Bureau of Land Management, Monte Vista, CO (United States); Walston, Lee [Argonne National Lab. (ANL), Argonne, IL (United States); Zvolanek, Emily A. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-10-01

    The San Luis Valley – Taos Plateau Landscape-Level Cultural Heritage Values and Risk Assessment (hereafter referred to as cultural assessment) is a BLM pilot project designed to see whether the Rapid Ecoregional Assessment (REA) framework (already established and implemented throughout many ecoregions in the West) can be applied to the cultural environment.

  7. Desert-steppe migration on the Loess Plateau at about 450 kaBP

    Institute of Scientific and Technical Information of China (English)

    ZHAOJingbo

    2005-01-01

    According to the field investigation, observation by an electronic microscope and x-ray identification and chemical analysis, desert-steppe migration in the Loess Plateau at about 450 kaBP was studied. The data show that gypsum illuvial horizon indicating the desert-steppe environment developed in the early stage of the formation of the fifth layer loess in Shaoling tableland in Chang'an and Bailu tableland in Xran of Shaanxi are situated in the southern Loess Plateau. This indicates that remarkable drying occurred, a large-scope migration of desert steppe took place toward south and the climate zone migrated 5 degrees in latitude to south which is the largest migration range indicated by geochemical indexes. The desert-steppe and more wild environment distributed widely on the Loess Plateau at that time. The development of gypsum also indicates that the climate changed at 450 kaBP from monsoon climate to nonmonsoon climate in the Loess Plateau, and the region was not affected by summer monsoon and was in the cold and dry environment of nonmonsoon climate. Annual mean nrecinitation was about 200 rnm. 400 mm less at that time than at oresent.

  8. New magnetochronology of Late Miocene mammal fauna, NE Tibetan Plateau, China : Mammal migration and paleoenvironments

    NARCIS (Netherlands)

    Ao, Hong; Zhang, Peng; Dekkers, Mark J.; Roberts, Andrew P.; An, Zhisheng; Li, Yongxiang; Lu, Fengyan; Lin, Shan; Li, Xingwen

    2016-01-01

    Lanzhou Basin lies on the northeastern margin of the Tibetan Plateau in western China and is a rich source of Oligocene-Miocene mammalian fossils. Obtaining precise age determinations for these fossils is important to address key questions concerning mammalian and environmental evolution in Asia

  9. Structure and multiphased evolution of the Demerara plateau (offshore Suriname, French Guiana)

    Science.gov (United States)

    Mercier de Lépinay, Marion; Basile, Christophe; Loncke, Lies; Maillard, Agnès; Grall, Céline; Roest, Walter R.; de Clarens, Philippe

    2014-05-01

    Offshore Suriname and French Guiana, the Demerara plateau is a continental indentation at the intersection of two oceanic domains : the Jurassic Central Atlantic and the Early Cretaceous Equatorial Atlantic. Its three borders are passive margins. The northern one is a transform margin, the two others are rifted margins, thinned during Trias/Jurassic (westward), and a second time during Early Cretaceous (eastward). The main stratigraphic feature of the Demerara plateau is the major upper Albian angular erosive unconformity, synchronous to the Equatorial Atlantic break-up. We here focus on the sedimentary records observed below the upper Albian discordance, where seismic data show more than 13 km of layered units. The aim of this study is to give new insights about the evolution of the Demerara plateau during Mesozoic times, in order to constrain vertical displacements especially in relation with the transform margin. We use mostly structural interpretation of industrial and academic seismic lines (GUYAPLAC, 2003 and IGUANES, 2013), calibrated by industrial wells down to Berriasian times. It allows us to propose structural maps and regional interpretative cross-sections of the plateau and its three borders. On seismic lines, undated prominent seismic units are characterized by important thickness variations, and weak continuity of intern reflectors. They thicken westward (toward the Central Atlantic ocean). One possible interpretation is to relate these units to trias/jurassic syn-rift sediments deposition associated to a continentward dipping fault. But the complex is formed by a repetition of several layer fans. Hence one alternative interpretation would be that these units were seaward dipping reflectors stacked during Trias/Jurassic rifting, suggesting that the role of magmatism should have been predominant during the first phase of the plateau formation. All the sediments of the plateau, including Aptian sediments, are deformed with numerous structures (strike

  10. Rapid regional surface uplift of the northern Altiplano plateau revealed by multiproxy paleoclimate reconstruction

    Science.gov (United States)

    Kar, Nandini; Garzione, Carmala N.; Jaramillo, Carlos; Shanahan, Timothy; Carlotto, Victor; Pullen, Alex; Moreno, Federico; Anderson, Veronica; Moreno, Enrique; Eiler, John

    2016-08-01

    The central Altiplano is inferred to have experienced ∼ 2.5 ± 1km surface uplift between ∼10 and 6 Ma, while the southern Altiplano experienced a similar magnitude of surface uplift that began earlier, between ∼16 and 9 Ma. To properly constrain the along strike timing of the Altiplano plateau surface uplift, it is necessary to know how and when the northernmost part of the Altiplano plateau evolved. We reconstruct the paleoclimate and infer the corresponding paleoelevation from the Miocene-Pliocene deposits of the Descanso-Yauri basin (14-15°S) in the northernmost part of the Altiplano plateau using 4 different proxies, including carbonate clumped isotope composition (i.e., Δ47 values), carbonate δ18Oc, leaf wax δDwax and pollen assemblages from paleosol, lacustrine and palustrine carbonates and organic-rich sediments. The isotopic signatures reflect past climate conditions of mean annual air temperature (Δ47) and meteoric water isotope values (δ18Oc, δDwax). Our results show that the northernmost plateau remained at low elevation (0.9 ± 0.8 to 2.1 ± 0.9km) until late Miocene time (∼9 Ma) characterized by ∼15 °C warmer than modern temperature (mean annual air temperature of 23 ± 4 °C, 2σ), low elevation vegetation and precipitation signature with reconstructed □ δ18Omw (VSMOW) of - 8.3 ± 2.0 ‰ (2 σ) from carbonate (δ18Oc) and - 8.6 ± 1.8 ‰ (2 σ) from leaf wax (δDwax). Modern elevations of 4 km were not reached until 5.4 ± 1.0Ma, as indicated by a negative shift in δDwax (VSMOW) from - 143.4 ± 12.8 ‰ (2 σ) to - 209.2 ± 21.1 ‰ (2 σ) between 9.1 ± 0.7 and 5.4 ± 1.0Ma. The timing of surface uplift of the northernmost Altiplano is consistent with the evidence for late Miocene surface uplift of the central Altiplano (16-19°S) between 10 and 6 Ma, and indicates that regional scale uplift in the northern-central plateau significantly postdates the onset of surface uplift in the southern Altiplano (19-22°S) between ∼16

  11. Quantifying sources, transport, deposition, and radiative forcing of black carbon over the Himalayas and Tibetan Plateau

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Rudong; Wang, Hailong; Qian, Yun; Rasch, Philip J.; Easter, Richard C.; Ma, Po-Lun; Singh, Balwinder; Huang, Jianping; Fu, Qiang

    2015-01-01

    Black carbon (BC)particles over the Himalayas and Tibetan Plateau (HTP), both airborne and those deposited on snow, have been shown to affect snowmelt and glacier retreat. Since BC over the HTP may originate from a variety of geographical regions and emission sectors, it is essential to quantify the source-receptor relationships of BC in order to understand the contributions of natural and anthropogenic emissions and provide guidance for potential mitigation actions. In this study, we use the Community Atmosphere Model version 5 (CAM5) with a newly developed source tagging technique, nudged towards the MERRA meteorological reanalysis, to characterize the fate of BC particles emitted from various geographical regions and sectors. Evaluated against observations over the HTP and surrounding regions, the model simulation shows a good agreement in the seasonal variation of the near-surface airborne BC concentrations, providing confidence to use this modeling framework for characterizing BC source- receptor relationships. Our analysis shows that the relative contributions from different geographical regions and source sectors depend on seasons and the locations in the HTP. The largest contribution to annual mean BC burden and surface deposition in the entire HTP region is from biofuel and biomass (BB) emissions in South Asia, followed by fossil fuel (FF) emissions from South Asia, then FF from East Asia. The same roles hold for all the seasonal means except for the summer when East Asia FF becomes more important. For finer receptor regions of interest, South Asia BB and FF have the largest impact on BC in Himalayas and Central Tibetan Plateau, while East Asia FF and BB contribute the most to Northeast Plateau in all seasons and Southeast Plateau in the summer. Central Asia and Middle East FF emissions have relatively more important contributions to BC reaching Northwest Plateau, especially in the summer. Although the HTP local emissions only contribute about 10% of BC in

  12. The Changing Pattern of Glaciers During Last 40 Years in Tibetan Plateau, China

    Science.gov (United States)

    Liu, S.; Guo, W.; Xu, J.; Li, J.; Wei, J.; Yu, P.

    2010-12-01

    As indicated from the first inventory of glaciers based on topographical maps in the 1960s and early 1980s in Tibetan Plateau, there are 36793 glaciers with total area and ice volume of 49873 km2 and 4561 km3, respectively, about 79 %, 84% and 81% of the total number, area and volume of glaciers in China. Glaciers are one of key factors in seasonal, annual and decadal variabilities of discharges of the well known large river systems like Yangtze, Ganges and so on in the region. Understanding the changes of glaciers in Tibetan Plateau is of significance to understand the availability of water resources that originated from glacierized basins and their potential impact on social-economic development and environmental conservation in the watersheds of high population density. To track the changes of glaciers in Tibetan Plateau during the past decades, we have compiled the current inventory of glaciers over the Tibetan Plateau, which was based on ASTER (Advanced Spaceborne Thermal Emission and Reflection radiometer) and Landsat TM imageries mostly acquired during late summers of 2005-2008. A band ratio threshold method was applied to orthorectified images for extraction of glacier outlines which were then carefully verified and modified manually (here referred to as CGI2008). These vectorized boundaries of glaciers were then compared with that of the first glacier inventory digitized based on aerial photos and topographical maps during the late 1950s and 1970s (referred to as CGI 1960s). Results demonstrates that glaciers in Tibetan Plateau have retreated significantly during last four decades with total areal reduction amounting to 16.3% or 0.47%/a. Glacier retreat exhibited distinctive spatial patterns with less changes in the central Tibetan Plateau, where glaciers belong to continental type of cold glacial base and low mass turnover rates. Obvious retreat of glaciers happened within the surrounding high mountainous ranges like the north slope of Himalaya, Qilian

  13. Cenozoic volcanism and lithospheric tectonic evolution in Qiangtang area, northern Qinghai-Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    CHI Xiaoguo; LI Cai; JIN Wei

    2005-01-01

    Following the collision between the Indian and Eurasian plates, the Cenozoic volcanic activities are rather frequent in the Qiangtang area of northern Qinghai-Tibet Plateau. They can be divided into four series: alkaline basalt series, high-K calc-alkaline series, shoshonitic series and peralkaline potassic-ultrapotassic series. Geochemical data suggest that the magma sources of Cenozoic volcanic rocks have transferred from spinel Iherzolite mantle in the early stage to garnet peridotite enriched mantle (EM2) in the later stage. The high Mg# number and extremely high Cr-Ni-Co abundance of high-K calc-alkaline and shoshonitic series andesites in the Qiangtang area indicate that the primary magma might be derived from subduction of continent lithosphere from the Lhasa block. Incompatible element ratios of La/Rb, Zr/Rb, Rb/Nb, K/Nb,Pb/La and K/La of peralkaline potassic-ultrapotassic series lavas in northern Qinghai-Tibet Plateau are lower than island arc volcanic rocks and higher than and similar to oceanic island basalts. This signature indicates that the primary magma derive from a paleo-mantle wedge interfused by fluids derived from asthenosphere and/or subducted mantle lithosphere. But the above element ratios of ultrapotassic lavas in southern Tibet and ultrapotassic lamprophyres in eastern Tibet are higher than and similar to island arc volcanic rocks, which means that the primary magma sources contained a large quantity of crust contaminant from fluids and/or melts derived from subducted continent lithosphere. The studies result supports that the indian continental .lithosphere has underthrust beneath Tibet to about the middle of the plateau, and Eurasian (Qaidam basin) mantle lithosphere has underthrust beneath the Qiangtang area of northern Tibet Plateau. In the paper we demonstrate further that the pulsing cycles of potassic-ultrapotassic volcanism of the Qinghai-Tibet Plateau result from an asthenospher pulsing upwelling caused by the intraplate subduction

  14. Method for evaluating the reliability of compressor impeller of turbocharger for vehicle application in plateau area

    Science.gov (United States)

    Wang, Zheng; Wang, Zengquan; Wang, A.-na; Zhuang, Li; Wang, Jinwei

    2016-10-01

    As turbocharging diesel engines for vehicle application are applied in plateau area, the environmental adaptability of engines has drawn more attention. For the environmental adaptability problem of turbocharging diesel engines for vehicle application, the present studies almost focus on the optimization of performance match between turbocharger and engine, and the reliability problem of turbocharger is almost ignored. The reliability problem of compressor impeller of turbocharger for vehicle application when diesel engines operate in plateau area is studied. Firstly, the rule that the rotational speed of turbocharger changes with the altitude height is presented, and the potential failure modes of compressor impeller are analyzed. Then, the failure behavior models of compressor impeller are built, and the reliability models of compressor impeller operating in plateau area are developed. Finally, the rule that the reliability of compressor impeller changes with the altitude height is studied, the measurements for improving the reliability of the compressor impellers of turbocharger operating in plateau area are given. The results indicate that when the operating speed of diesel engine is certain, the rotational speed of turbocharger increases with the increase of altitude height, and the failure risk of compressor impeller with the failure modes of hub fatigue and blade resonance increases. The reliability of compressor impeller decreases with the increase of altitude height, and it also decreases as the increase of number of the mission profile cycle of engine. The method proposed can not only be used to evaluating the reliability of compressor impeller when diesel engines operate in plateau area but also be applied to direct the structural optimization of compressor impeller.

  15. IOD influence on the early winter tibetan plateau snow cover: diagnostic analyses and an AGCM simulation

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Chaoxia; Tozuka, Tomoki; Yamagata, Toshio [The University of Tokyo, Department of Earth and Planetary Science, Graduate School of Science, Tokyo (Japan)

    2012-10-15

    Using diagnostic analyses and an AGCM simulation, the detailed mechanism of Indian Ocean Dipole (IOD) influence on the early winter Tibetan Plateau snow cover (EWTPSC) is clarified. In early winter of pure positive IOD years with no co-occurrence of El Nino, the anomalous dipole diabatic heating over the tropical Indian Ocean excites the baroclinic response in the tropics. Since both baroclinic and barotropic components of the basic zonal wind over the Arabian Peninsula increase dramatically in early winter due to the equatorward retreat of the westerly jet, the baroclinic mode excites the barotropic Rossby wave that propagates northeastward and induces a barotropic cyclonic anomaly north of India. This enables the moisture transport cyclonically from the northern Indian Ocean toward the Tibetan Plateau. The convergence of moisture over the plateau explains the positive influence of IOD on the EWTPSC. In contrast, the basic zonal wind over the Arabian Peninsula is weak in autumn. This is not favorable for excitation of the barotropic Rossby wave and teleconnection, even though the IOD-related diabatic heating anomaly in autumn similar to that in early winter exists. This result explains the insignificant (significant positive) partial correlation between IOD and the autumn (early winter) Tibetan Plateau snow cover after excluding the influence of ENSO. The sensitivity experiment forced by the IOD-related SST anomaly within the tropical Indian Ocean well reproduces the baroclinic response in the tropics, the teleconnection from the Arabian Peninsula, and the increased moisture supply to the Tibetan Plateau. Also, the seasonality of the atmospheric response to the IOD is simulated. (orig.)

  16. Response of grain size of Quaternary gravels to climate and tectonics in the northern Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The widely distributed thick gravel deposits along the rim of the Tibetan Plateau have been long thought to be the product of rapid tectonic uplift of the plateau. However, this has been challenged by recent works that suggest these thick gravels may be the result of climate change. In this paper we carried out a detailed field measurement of gravel grain sizes from the Jiuquan and Gobi Gravel Beds in the top of the Laojunmiao section in the Jiuxi Basin in the northern margin of Qilian Mts. (northern Tibetan Plateau). The results suggest that the grain sizes of the Jiuquan and Gobi Gravel Beds over the last 0.8 Ma are characterized by nine coarse-fine cycles having strong 100-ka and 41-ka periodicities that correlate well with the loess-paleosol monsoon record and isotopic global climatic record from deep sea sediments as well as by a long trend of coarsening in gravel grain size. The coarse gravel layers were formed during the warm-humid interglaciations while the fine layers correspond to the cold-dry glaciations. Because the paleoclimate in NW China began to get dramatically drier after the mid-Pleistocene, we think the persistent coarsening of gravel grain size was most probably caused by the rapid uplift of the northern Tibetan Plateau, and that the orbital scale cyclic variations in gravel grain size were driven by orbital forcing factors that were superimposed on the tectonically-forced long-term coarsening trend in gravel size. These findings also shed new light on the interaction results of climate and tectonics in relation to the uplift of the Tibetan Plateau.

  17. Warming in Arctic intermediate and deep waters around Chukchi Plateau and its adjacent regions in 1999

    Institute of Scientific and Technical Information of China (English)

    ZHAO; Jinping; GAO; Guoping

    2005-01-01

    Based on the data measured during Arctic scientific expedition of China in 1999, the characteristics of temperature and salinity distributions around the Chukchi Plateau and its adjacent regions have been studied. It was found that the intermediate water with temperature higher than 0.5℃ existed in all parts of a 640 km section with a maximum temperature of 0.85℃ indicating a strong signal of the warming in Arctic Intermediate Water in 1999. Two important phenomena are described in this paper. First, the temperature of warm water was horizontally nonuniform. In the area of Chukchi Plateau, the temperature was higher, the layer of warm water was thicker and the depth of the warm water core was shallower than those in the area of continental slope. The horizontal nonuniformity of the temperature distribution of warming water implies that the upward heat flux should also be nonuniform, thus exerting different effects on sea ice thickness, ice extent, and air-sea heat exchange. The mechanism to generate higher temperature in the plateau region was the bypassing of current around the plateau area caused by the special local topography, which restricted water exchange across the plateau and conserved heat in the water body. Second, the deep water down to 1400 m was also warming with a temperature increase of 0.2℃. The warming in deep water reflects the occurrence of complicated heat redistribution processes in the intermediate water, which altered the thermal structure in the upper 1400 m. The warming data embody the obvious impact of global climate change on the Arctic Ocean and further studies are wanted.

  18. Trends in spring and autumn phenology over the Tibetan Plateau based on four NDVI datasets

    Science.gov (United States)

    Wang, X.; Xiao, J.; Li, X.; Cheng, G.; Ma, M.

    2016-12-01

    Vegetation phenology is a sensitive indicator of climate change, and has significant effects on ecosystem carbon uptake. As the Earth's "third pole", the Tibetan Plateau has witnessed rapid warming during the last several decades. The Tibetan Plateau is a unique region to study the trends in vegetation phenology in response to climate change because of the sensitivity of its ecosystems to climate and its low-level human disturbance. The trends in spring and autumn phenology over the plateau are highly controversial. In this study, we examine the trends in the start of growing season (SOS) and end of growing season (EOS) for alpine meadow and steppe using the GIMMS NDVI3g dataset (1982-2013), the GIMMS NDVI dataset (1982-2006), the MODIS NDVI dataset (2001-2013) and the SPOT Vegetation NDVI dataset (1999-2013). Both logistic and polynomial fitting models are used to estimate the SOS and EOS dates. The results are evaluated at four meadow/steppe phenology observation stations. The NDVI-derived SOS and EOS dates are systematically greater than the field-based SOS (emergence seedling date) and EOS (wilting date). There are large discrepancies in both spring and autumn phenology among the different NDVI datasets. For a given NDVI dataset, both SOS and EOS also exhibit significant differences between the two different approaches. Our results show that the trends in spring and autumn phenology over the Tibetan Plateau depend on both the NDVI dataset used and the method for retrieving the SOS and EOS dates. There is no consistent evidence that the "green-up" dates (SOS) has been advancing over the Tibetan Plateau during the last two decades.

  19. Simulation for Artificial Forest Succession in Hilly-gully Area of Loess Plateau, China

    Science.gov (United States)

    Zhao, J., Jr.; Zhao, Z.; Yang, Y.

    2015-12-01

    The wide and large afforestation caused the great changes of surface albedo, water cycles, soil compositions and regional climate conditions on the Loess Plateau. There was increasing evidence showed that many problems had been occurred since ecological protection program began. Whether the artificial forest would adapt to environmental conditions on Loess Plateau is still controversial. In this paper, LANDIS-II, a spatially explicit model which included extension modules such as succession, disturbance, seed propagation, forest management, carbon dynamics and climate change, was applied to simulate dynamic natural succession of forests for coming 300 years in hilly-gully area of Loess Plateau. The results showed that (1) During the advancement of succession, the study area was occupied by different communities and appeared different succession stage successively under the condition of without considering the disturbance; (2) The current artificial forest has changed from 93.31% of Robinia pseudoacacia to exit the forest community in 50 years; (3) Platycladus oriental was the dominant species of coniferous trees and Populus davidiana was the dominant species of deciduous trees; (4)During the late succession stage, Platycladus oriental replaced Pinus tabulaeformis becoming the largest areal proportion of dominant tree species. The simulating of the natural succession in hilly-gully area of Loess Plateau forests at large space and long term scales, could provide a scientific basis for rational allocation of forest resources and forest management. In addition, our work clarifies the challenges and opportunities for the application of the model in the artificial forest and in hilly-gully area of Loess Plateau, China.

  20. Palynological evidence for late Miocene stepwise aridification on the northeastern Tibetan Plateau

    Science.gov (United States)

    Liu, Jia; Li, Ji Jun; Song, Chun Hui; Yu, Hao; Jiang Peng, Ting; Chuang Hui, Zheng; Ye, Xi Yan

    2016-07-01

    Holding a climatically and geologically key position both regionally and globally, the northeastern Tibetan Plateau provides a natural laboratory for illustrating the interactions between tectonic activity and the evolution of the Asian interior aridification. Determining when and how the late Miocene climate evolved on the northeastern Tibetan Plateau may help us better understand the relationships among tectonic uplift, global cooling and ecosystem evolution. Previous paleoenvironmental research has focused on the western Longzhong Basin. Late Miocene aridification data derived from pollen now require corroborative evidence from the eastern Longzhong Basin. Here, we present a late Miocene pollen record from the Tianshui Basin in the eastern Longzhong Basin. Our results show that a general trend toward dry climate was superimposed by stepwise aridification: a temperate forest with a rather humid climate existed in the basin between 11.4 and 10.1 Ma, followed by a temperate open forest environment with a less humid climate between 10.1 and 7.4 Ma, then giving way to an open temperate forest-steppe environment with a relatively arid climate between 7.4 and 6.4 Ma. The vegetation succession demonstrates that the aridification of the Asian interior occurred after ˜ 7-8 Ma, which is confirmed by other evidence from Asia. Furthermore, the aridification trend on the northeastern Tibetan Plateau parallels the global cooling of the late Miocene; the stepwise vegetation succession is consistent with the major uplift of the northeastern Tibetan Plateau during this time. These integrated environmental proxies indicate that the long-term global cooling and the Tibetan Plateau uplift caused the late Miocene aridification of the Asian interior.

  1. On the nature of the plateau in two-step dinuclear spin-crossover complexes.

    Science.gov (United States)

    Ksenofontov, Vadim; Gaspar, Ana B; Niel, Virginie; Reiman, Sergey; Real, José A; Gütlich, Philipp

    2004-03-05

    A remarkable feature of the spin-crossover process in several dinuclear iron(II) compounds is a plateau in the two-step transition curve. Up to now, it has not been possible to analyse the spin state of dinuclear pairs that constitute such a plateau, due to the relative high temperatures at which the transition takes place in complexes investigated so far. We solved this problem by experimentally studying a novel dinuclear spin-crossover compound [[Fe(phdia)(NCS)(2)](2)(phdia)] (phdia: 4,7-phenanthroline-5,6-diamine). We report here on the synthesis and characterisation of this system, which exhibits a two-step spin transition at T(c1)=108 K and T(c2)=80 K, displaying 2 K and 7 K wide thermal hysteresis loops in the upper and the lower steps, respectively. A plateau of approximately 20 K width centred at about 90 K, which corresponds to the 50 % of the spin conversion, separates the two transitions. The composition of the plateau was identified in metastable state after quenching to 4.2 K by means of Mössbauer spectroscopy in an external magnetic field. Such experiments revealed that the plateau consists mainly of [HS-LS] pairs (HS=high spin, LS=low spin) and confirmed the hypothesis that the spin conversion in dinuclear entities proceeds through [LS-LS][HS-LS][HS-HS] pairs. The results are discussed in terms of a thermodynamic model based on the regular solution theory adapted for dinuclear spin-crossover compounds.

  2. Origin and radiative forcing of black carbon transported to the Himalayas and Tibetan Plateau

    Science.gov (United States)

    Kopacz, M.; Mauzerall, D. L.; Wang, J.; Leibensperger, E. M.; Henze, D. K.; Singh, K.

    2011-03-01

    The remote and high elevation regions of central Asia are influenced by black carbon (BC) emissions from a variety of locations. BC deposition contributes to melting of glaciers and questions exist, of both scientific and policy interest, as to the origin of the BC reaching the glaciers. We use the adjoint of the GEOS-Chem model to identify the location from which BC arriving at a variety of locations in the Himalayas and Tibetan Plateau originates. We then calculate its direct and snow-albedo radiative forcing. We analyze the seasonal variation in the origin of BC using an adjoint sensitivity analysis, which provides a detailed map of the location of emissions that directly contribute to black carbon concentrations at receptor locations. We find that emissions from northern India and central China contribute the majority of BC to the Himalayas, although the precise location varies with season. The Tibetan Plateau receives most BC from western and central China, as well as from India, Nepal, the Middle East, Pakistan and other countries. The magnitude of contribution from each region varies with season and receptor location. We find that sources as varied as African biomass burning and Middle Eastern fossil fuel combustion can significantly contribute to the BC reaching the Himalayas and Tibetan Plateau. We compute radiative forcing in the snow-covered regions and find the forcing due to the BC induced snow-albedo effect to vary from 5-15 W m-2 within the region, an order of magnitude larger than radiative forcing due to the direct effect, and with significant seasonal variation in the northern Tibetan Plateau. Radiative forcing from reduced snow albedo likely accelerates glacier melting. Our analysis may help inform mitigation efforts to slow the rate of glacial melt by identifying regions that make the largest contributions to BC deposition in the Himalayas and Tibetan Plateau.

  3. Dynamic contact mechanics on the tibial plateau of the human knee during activities of daily living.

    Science.gov (United States)

    Gilbert, Susannah; Chen, Tony; Hutchinson, Ian D; Choi, Dan; Voigt, Clifford; Warren, Russell F; Maher, Suzanne A

    2014-06-27

    Despite significant advances in scaffold design, manufacture, and development, it remains unclear what forces these scaffolds must withstand when implanted into the heavily loaded environment of the knee joint. The objective of this study was to fully quantify the dynamic contact mechanics across the tibial plateau of the human knee joint during gait and stair climbing. Our model consisted of a modified Stanmore knee simulator (to apply multi-directional dynamic forces), a two-camera motion capture system (to record joint kinematics), an electronic sensor (to record contact stresses on the tibial plateau), and a suite of post-processing algorithms. During gait, peak contact stresses on the medial plateau occurred in areas of cartilage-cartilage contact; while during stair climb, peak contact stresses were located in the posterior aspect of the plateau, under the meniscus. On the lateral plateau, during gait and in early stair-climb, peak contact stresses occurred under the meniscus, while in late stair-climb, peak contact stresses were experienced in the zone of cartilage-cartilage contact. At 45% of the gait cycle, and 20% and 48% of the stair-climb cycle, peak stresses were simultaneously experienced on both the medial and lateral compartment, suggesting that these phases of loading warrant particular consideration in any simulation intended to evaluate scaffold performance. Our study suggests that in order to design a scaffold capable of restoring 'normal' contact mechanics to the injured knees, the mechanics of the intended site of implantation should be taken into account in any pre-clinical testing regime.

  4. Mid-Pliocene onset of eccentricity cycles in the Zhada Basin, southwestern Tibetan Plateau.

    Science.gov (United States)

    Saadeh, C. M.; Saylor, J. E.; Shanahan, T. M.; Nie, J.

    2015-12-01

    Changes in the Asian Monsoon driven by Tibetan Plateau uplift have been invoked to explain late Miocene-Pliocene biological turnover and increases in erosion and sediment accumulation. However, documentation of pre-Miocene uplift of the plateau and evidence for early appearance of the Asian Monsoon system has called these conclusions into question. We present a high-resolution, long-term record of environmental change at 3.5-4.5 km essential to understanding the impact and causes of monsoon variation. The O and C isotopic record of authigenic carbonate in 566 samples from the Zhada Basin extends from 8.99 to 1.75 Ma. Both the δ18O and stratigraphic record indicate long-term changes in basin hydrology which may reflect the impact of regional tectonics on drainage reorganization. These long-term changes are characterized by an onset of lacustrine deposition coupled with an increase in mean δ18O values at 6.11 Ma followed by a return to palustrine/fluvial deposition and a decrease in mean δ18O values at 3.24 Ma. These Miocene-early Pleistocene Zhada Basin results mimic late Pleistocene-Holocene paleoclimatic records across the Tibetan Plateau suggesting similar driving mechanisms. Frequency analysis of the δ18O record reveals that Milankovitch cycles are recorded in the Zhada Basin; suggesting that insolation-driven climate change drove high-frequency environmental changes in the southern Tibetan Plateau. Counterintuitively, non-stationary frequency analysis of the δ18O record indicates strengthening in the 100 kyr (eccentricity) band: coincident with initial onset of Northern Hemisphere Glaciation, but ~2.4 Myr prior to strengthening in the marine record. The discrepancy between marine and high-elevation records suggests that changes in the character of the ISM may be responding to cooling in the Pacific Ocean, and may be responsible for widespread mid-Pliocene changes observed on the peripheries of the Tibetan Plateau.

  5. Origin and radiative forcing of black carbon transported to the Himalayas and Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    M. Kopacz

    2011-03-01

    Full Text Available The remote and high elevation regions of central Asia are influenced by black carbon (BC emissions from a variety of locations. BC deposition contributes to melting of glaciers and questions exist, of both scientific and policy interest, as to the origin of the BC reaching the glaciers. We use the adjoint of the GEOS-Chem model to identify the location from which BC arriving at a variety of locations in the Himalayas and Tibetan Plateau originates. We then calculate its direct and snow-albedo radiative forcing. We analyze the seasonal variation in the origin of BC using an adjoint sensitivity analysis, which provides a detailed map of the location of emissions that directly contribute to black carbon concentrations at receptor locations. We find that emissions from northern India and central China contribute the majority of BC to the Himalayas, although the precise location varies with season. The Tibetan Plateau receives most BC from western and central China, as well as from India, Nepal, the Middle East, Pakistan and other countries. The magnitude of contribution from each region varies with season and receptor location. We find that sources as varied as African biomass burning and Middle Eastern fossil fuel combustion can significantly contribute to the BC reaching the Himalayas and Tibetan Plateau. We compute radiative forcing in the snow-covered regions and find the forcing due to the BC induced snow-albedo effect to vary from 5–15 W m−2 within the region, an order of magnitude larger than radiative forcing due to the direct effect, and with significant seasonal variation in the northern Tibetan Plateau. Radiative forcing from reduced snow albedo likely accelerates glacier melting. Our analysis may help inform mitigation efforts to slow the rate of glacial melt by identifying regions that make the largest contributions to BC deposition in the Himalayas and Tibetan Plateau.

  6. The Colorado Plateau III: integrating research and resources management for effective conservation

    Science.gov (United States)

    Sogge, Mark K.; van Riper, Charles

    2008-01-01

    Roughly centered on the Four Corners region of the southwestern United States, the Colorado Plateau covers an area of 130,000 square miles. The relatively high semi-arid province boasts nine national parks, sixteen national monuments, many state parks, and dozens of wilderness areas. With the highest concentration of parklands in North America and unique geological and ecological features, the area is of particular interest to researchers. Derived from the Eighth Biennial Conference of Research on the Colorado Plateau, this third volume in a series of research on the Colorado Plateau expands upon the previous two books. This volume focuses on the integration of science into resource management issues, summarizes what criteria make a successful collaborative effort, outlines land management concerns about drought, provides summaries of current biological, sociological, and archaeological research, and highlights current environmental issues in the Four Corner States of Arizona, New Mexico, Colorado, and Utah. With broad coverage that touches on topics as diverse as historical aspects of pronghorn antelope movement patterns through calculating watershed prescriptions to the role of wind-blown sand in preserving archaeological sites on the Colorado River, this volume stands as a compendium of cuttingedge management-oriented research on the Colorado Plateau. The book also introduces, for the first time, tools that can be used to assist with collaboration efforts among landowners and managers who wish to work together toward preserving resources on the Colorado Plateau and offers a wealth of insights into land management questions for many readers, especially people interested in the natural history, biology, anthropology, wildlife, and cultural management issues of the region.

  7. Origin and radiative forcing of black carbon transported to the Himalayas and Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    M. Kopacz

    2010-09-01

    Full Text Available The remote and high elevation regions of central Asia are influenced by black carbon (BC emissions from a variety of locations. BC deposition contributes to melting of glaciers and questions exist, of both scientific and policy interest, as to the origin of the BC reaching the glaciers. We use the adjoint of the GEOS-Chem model to identify the location from which BC arriving at a variety of locations in the Himalayas and Tibetan Plateau originates. We then calculate its direct and snow-albedo radiative forcing. We analyze the seasonal variation in the origin of BC using an adjoint sensitivity analysis, which provides a detailed map of the location of emissions that directly contribute to black carbon concentrations at receptor locations. We find that emissions from northern India and central China contribute the majority of BC to the Himalayas, although the precise location varies with season. The Tibetan Plateau receives most BC from western and central China, as well as from India, Nepal, the Middle East, Pakistan and other countries. The magnitude of contribution from each region varies with season and receptor location. We find that sources as varied as African biomass burning and Middle Eastern fossil fuel combustion can significantly contribute to the BC reaching the Himalayas and Tibetan Plateau. We compute radiative forcing in the snow-covered regions and estimate the forcing due to the BC induced snow-albedo effect at about 5–15 W m−2 within the region, an order of magnitude larger than radiative forcing due to the direct effect, and with significant seasonal variation in the northern Tibetan Plateau. Radiative forcing from reduced snow albedo accelerates glacier melting. Our analysis can help inform mitigation efforts to slow the rate of glacial melt by identifying regions that make the largest contributions to BC deposition in the Himalayas and Tibetan Plateau.

  8. A Comparative Study of the Electrical Structure of Circum Tibetan Plateau Orogenic Belts and its Tectonic Implications

    Science.gov (United States)

    Jin, Sheng; Zhang, Letian; Wei, Wenbo; Ye, Gaofeng; Jing, Jianen; Dong, Hao; Xie, Chengliang; Yin, Yaotian

    2017-04-01

    The Tibetan Plateau, as known as "roof of the world", was created through the on-going continent-continent collision between the Indian and Eurasian plates since 55 Ma. As the process continues, the plateau is growing both vertically and horizontally. The horizontal expansion of the plateau is blocked by the Yangtze block in the east, the Tarim block in the north, and the Ordos block in the northeast, and consequently lead to the formation of the circum Tibetan plateau orogenic belts. To better understand the mechanism behind this process, we conducted a comparative study by collecting 7 magnetotelluric (MT) profiles over the margins of the Tibetan plateau, namely, the INDEPTH 100, 700 and 800 lines in the southern Tibet, the INDEPTH 4000 and 5000 lines across the Altyn Tagh fault on the northern margin of the plateau, as well as other two profiles across the Haiyuan fault and the Longmenshan fault on the northeastern and eastern margins of the plateau deployed under the framework of project SinoProbe. The electrical features of the stable blocks surrounding the Tibetan plateau are generally resistive, while crustal conductive layers are found to be wide spread within the plateau. The southern margin of the Tibetan plateau is characterized by large scale underthrust of the Indian lithosphere beneath the plateau. This intense converging process created the thrust fault system distributed along the southern margin of the Tibetan plateau over 1000 km. Crustal conductive layers discovered in southern Tibet are generally associated with the southward crustal flow that originated from the lower crust within the plateau and exhumed along the thrust belts in the Himalayas. On the eastern margin of the Tibetan plateau, the electrical structures suggest that the Yangtze block wedged into the Tibetan lithosphere and caused decoupling between the crust and upper mantel. Large scale conductors discovered beneath the Songpan-Ganze block reflect that the eastward crustal flow was

  9. Relationship model of sediment grain size and Tibetan Plateau uplift in middle-west parts of Qilian Mountain

    Institute of Scientific and Technical Information of China (English)

    傅开道; 李吉均; 高军平; 方小敏

    2001-01-01

    By observing, measuring the fluvial sediment grain size of mid-western segment of the Qilianshan Range and studying the correlation between the grain size and uplift of the plateau, we model the correlation. These models are applied to the Laojunmiao section and the process curve of the uplift of the northern Tibetan Plateau against age from 8.35 Ma is illustrated here. The process curve shows that the northern Tibetan Plateau surface has uplifted from the mean altitude of 900-3700 m since 8.35 MaBP. From 8.35 to 3.1 MaBP, the Tibetan Plateau uplifted slowly, uplifted amplitude is small, the total range is 420 m. From 3.1 MaBP up to now, the Tibetan Plateau uplifted tempestuously, showing that the uplift accelerated obviously later. It uplifted totally 2400 m. About 0.9 Ma ago, the northern Tibetan Plateau surface had uplifted to over 3000 m a.s.l., showing that the Tibetan Plateau surface had reached the cryosphere; and the mountain peaks had uplifted to more than 4000 m altitude, suggesting that there

  10. Plateau potentials in sacrocaudal motoneurons of chronic spinal rats, recorded in vitro.

    Science.gov (United States)

    Bennett, D J; Li, Y; Siu, M

    2001-10-01

    Intracellular recordings were made from sacrocaudal tail motoneurons of acute and chronic spinal rats to examine whether plateau potentials contribute to spasticity associated with chronic injury. The spinal cord was transected at the S2 level, causing, over time, exaggerated long-lasting reflexes (hyperreflexia) associated with a general spasticity syndrome in the tail muscles of chronic spinal rats (1-5 mo postinjury). The whole sacrocaudal spinal cord of chronic or acute spinal rats was removed and maintained in vitro in normal artificial cerebral spinal fluid (ACSF). Hyperreflexia in chronic spinal rats was verified by recording the long-lasting ventral root responses to dorsal root stimulation in vitro. The intrinsic properties of sacrocaudal motoneurons were studied using intracellular injections of slow triangular current ramps or graded current pulses. In chronic spinal rats, the current injection triggered sustained firing and an associated sustained depolarization (plateau potential; 34/35 cells; mean, 5.5 mV; duration >5 s; normal ACSF). The threshold for plateau initiation was low and usually corresponded to an acceleration in the membrane potential just before recruitment. After recruitment and plateau activation, the firing rate changed linearly with current during the slow ramps [63% of cells had a linear frequency-current (F-I) relation] despite the presence of the plateau. The persistent inward current (I(PIC)) producing the plateau and sustained firing was estimated to be on average 0.8 nA as determined by the reduction in injected current needed to stop the sustained firing [DeltaI = -0.8 +/- 0.6 (SD) nA], compared with the current needed to start firing (I = 1.7 +/- 1.5 nA; 47% reduction). In motoneurons of acute spinal rats, plateaus were rarely seen (3/22), although they could be made to occur with bath application of serotonin. In motoneurons of chronic spinal rats there were no significant changes in the mean passive input resistance

  11. Multidisciplinary scientific program of investigation of the structure and evolution of the Demerara marginal plateau

    Science.gov (United States)

    Loncke, Lies; Basile, Christophe; Roest, Walter; Graindorge, David; Mercier de Lépinay, Marion; Klinghelhoefer, Frauke; Heuret, Arnauld; Pattier, France; Tallobre, Cedric; Lebrun, Jean-Frédéric; Poetisi, Ewald; Loubrieu, Benoît; Iguanes, Dradem, Margats Scientific Parties, Plus

    2017-04-01

    Mercier de Lépinay et al. published in 2016 an updated inventory of transform passive margins in the world. This inventory shows that those margins represent 30% of continental passive margins and a cumulative length of 16% of non-convergent margins. It also highlights the fact that many submarine plateaus prolong transform continental margins, systematically at the junction of oceanic domains of different ages. In the world, we identified twenty of those continental submarine plateaus (Falklands, Voring, Demerara, Tasman, etc). Those marginal plateaus systematically experiment two phases of deformation: a first extensional phase and a second transform phase that allows the individualization of those submarine reliefs appearing on bathymetry as seaward continental-like salients. The understanding of the origin, nature, evolution of those marginal plateaus has many scientific and economic issues. The Demerara marginal plateau located off French Guiana and Surinam belongs to this category of submarine provinces. The French part of this plateau has been the locus of a first investigation in 2003 in the framework of the GUYAPLAC cruise dedicated to support French submissions about extension of the limit of the continental shelf beyond 200 nautical miles. This cruise was the starting point of a scientific program dedicated to geological investigations of the Demerara plateau that was sustained by different cruises and collaborations (1) IGUANES (2013) that completed the mapping of this plateau including off Surinam, allowed to better understand the segmentation of the Northern edge of this plateau, and to evidence the combined importance of contourite and mass-wasting processes in the recent sedimentary evolution of this domain, (2) Collaboration with TOTAL (Mercier de Lépinay's PhD thesis) that allowed to better qualify the two main phases of structural evolution of the plateau respectively during Jurassic times for its Western border, Cretaceous times for its

  12. Changes in lake areas on the Tibetan Plateau from 1972 to present

    Science.gov (United States)

    Abbey, A. L.; Hudson, A. M.; Kapp, P. A.; Quade, J.

    2012-12-01

    We determined changes in th areas of selected lakes on the Qinghai-Tibetan Plateau, from the 1970's to present, to evaluate their significance in terms of lake hydrology and climate. The Qinghai-Tibetan Plateau is covered by thousands of lakes ranging in size from a few square kilometers to several thousand square kilometers. Many of the lakes are located in internally drained basins, where lake area can be used as a direct indicator of the hydrologic budget within the basin. Eight internally drained lakes were chosen to represent four regions on the plateau (NE, NW, SE, and SW); in each region, one lake basin is fed by glacial runoff and one lake basin has no modern glaciers, in its catchment area. For each lake, classification mapping was done using ArcGIS and Landsat images from the 1970's to present. Changes in lake area were measured by extracting the pixels that made up the lake in each image. Lake area time series for each basin showed that between 1972 and 1997 lake level decreased or had no change (0% to -25%). From 1998 to present, all lakes show an increasing trend in area, ranging from 2% - 108%. Precipitation over the study period has not changed significantly, and not equally in all regions, and therefore is an unlikely explanation for lake expansion. Although glacier melt may be contributing to the increase in lake areas in glaciated watersheds, this cannot the lake area increases in non-glaciated watersheds. In contrast to changes in regional precipitation, mean annual temperature has been increasing relatively uniformly across the plateau since the 1950's. The plateau is almost entirely covered in frozen ground, and in response to these warmer air temperatures (and average annual ground temperatures), the frozen ground has been degrading over the past 50 years. We suggest that a threshold temperature was reached in 1998 that caused accelerated permafrost degradation, and since then, permafrost melting has been an important process contributing to

  13. Receiver function structures beneath the deep large faults in the northeastern margin of the Tibetan Plateau

    Science.gov (United States)

    Shen, Xuzhang; Zhou, Yuanze; Zhang, YuanSheng; Mei, Xiuping; Guo, Xiao; Liu, Xuzhou; Qin, Manzhong; Wei, Congxin; Li, Cuiqin

    2014-01-01

    Using the teleseismic P- and S-wave receiver functions of the dense linear temporary seismic array, the crust and uppermost mantle structures beneath the deep large faults in the northeastern margin of the Tibetan Plateau were imaged. The images of the first converted wave and the multiples indicated that the North Fault Zone of West Qinling (NWQ) Mountain and Diebu-Lueyang (DBL) faults cut the Mohorovicic (Moho) Discontinuity and cause an obvious difference feature for the Moho in the two sides of the faults. The higher Vp/Vs ratio and lower velocity layer is found beneath the west portion of the array near the Tibetan Plateau, which implies a lower crust channel flow coming from the Tibetan Plateau. The weak Moho and higher Vp/Vs ratio beneath the eastern portion of the array near the Ordos suggest the upwelling of the hot mantle material. The results also indicate an obvious deformation in the upper crust with the lower Vp/Vs ratio beneath the middle of the array. Such upper crust deformation is closely related to the topography of the surface; therefore, we deduce that the deformation of the brittle upper crust is accompanied by the formation of the local topography during the uplift of the Tibetan Plateau, which is also the primary reason for the active seismicity in the study region. The deformation of the lithosphere-asthenosphere boundary (LAB) can also be associated with the formation of the diapir caused by the upwelling hot materials in the upper mantle due to the uprising of the thrusting plate caused by the subduction of the India Plate. The existence of the lower crust channel flow, the crust shortening, and the mantle diapir in the local region simultaneously implies that the elevation and formation of the Tibetan Plateau cannot be explained with a single model. The higher resolution results for the crust and the mantle, especially beneath the block boundary region, are necessary to construct the completed geodynamic model to understand the formation

  14. Impact of Cryosphere Hydrological Changes on the River Runoff in the Tibetan Plateau

    Science.gov (United States)

    Wang, Y.; Yang, D.

    2015-12-01

    The Tibetan Plateau is the headwaters of many major rivers in Asia, the change in streamflow is significant for social and economic development and natural ecology in the middle and lower reaches. Located in the alpine region, streamflow in the plateau is mainly affected by the cryosphere hydrological processes. Due to global warming in recent decades, the Tibetan Plateau is experiencing glaciers shrinking and permafrost degradation. Accelerated glacier melt led to the increasing meltwater, thus affecting the streamflow. Permafrost is an important factor in stabilizing the water cycle and streamflow, the ecological degradation and the significant changes of rivers, lakes, swamps, wetlands and other hydrological environment in recent decades in the Tibetan plateau is closely related to permafrost degradation. Therefore, it is important to explore the impact of cryosphere hydrological changes on the streamflow for the future water management. This study uses a method of base flow separation and a stepwise multiple regression model to investigate the reasons for the runoff changes in different regions of the Tibetan Plateau during 1960-2000. The contribution of glacier melt to annual runoff is particularly estimated to explore the possible influences of soil freezing and thawing on annual runoff changes. The results show an increasing trend of the annual runoff in the upstream of Nujiang River, Lancang River and Qilian Mountains, dominated by the increasing of base flow; and a decreasing trend of the runoff in the upper reach of the Yarlung Zangbo River, Yellow River and Yangtze River, dominated by the reduction of quick flow. Change in the amount of runoff was mainly due to change in precipitation. Rising temperature accelerates the melting of glaciers and increases the summer quick flow. In addition, rising temperature may reduce the quick flow and increase the base flow due to change of the active permafrost layers, which leads to the increase of soil water storage

  15. Crustal and upper mantle structure of central Qiangtang terrane (Tibet Plateau) imaged with magnetotelluric data

    Science.gov (United States)

    Zeng, S.; Hu, X.; Li, J.

    2013-12-01

    Since the Tethys Ocean closed, the ongoing collision between India and Aisa continents has created the Tibet Plateau, which is the most spectacular topographic feature on the surface of the earth. In the last decades, a large number of geological and geophysical studies have been undertaken in the Tibet Plateau, but most of these studies were focused on southern Tibet, where the collision of the Indian tectonic plate with Eurasia was occurred, and southeast Tibet, where lateral extrusion of crustal material may be occurred, absent in the central Tibet. As research continues, it has become clear that a complete understanding of the formation and deformation of the Tibet Plateau requires a study of the entire plateau. The Qiangtang terrane is located in the central Tibet Plateau. In 1993-1994, three profiles of broadband MT data (320 Hz to 2000 s) along N-S trending ranges from 86°E to 91°E were collected by China University of Geoscience in central Qiangtang terrane for the purpose of oil and gas exploration, the previous interpretation was focused on the shallow structures. In this study, we reanalyze the three MT profiles to produce more detailed images of the deep electrical structure of the Qiangtang terrane. Dimensionality analysis and geoelectric strike analysis of these data show that they appear to be two dimensional. 2-D inversion model show that there is a pervasive conductivity layer in the mid- to lower crustal and upper mantle, especially in the north Qiangtang terrane, which was considered to be the result of partial melt. The partial melt fraction is sufficient for crustal flow to occur. The similarity of the inversion models of the three profiles show that there is west-east crustal flow along the Jinsha River suture in central Qiangtang terrane, which seems to be western extension of the crustal flow observed in southeast Tibet by Bai et al. (2010). The inversion results also show difference of the electrical structure between the west and east

  16. Development of highway constructing technology in the permafrost region on the Qinghai-Tibet plateau

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The Qinghai-Tibet Highway passes through the Qinghai-Tibet plateau hinterland from north to south, from Kunlun Mountain to Tanggula Mountain. The average altitude is above 4500 m and permafrost covers more than 700 km length of area with high elevation and high temperature. The climate of the plateau is capricious and the surroundings along the road are bad, where the mean annual atmosphere temperature is -2 to -7℃ and the oxygen content is inadequate, which is less than 50% of the sea level, while the solar radiation is higher than 3600 kJ/m2. The basic characteristics of the plateau surroundings are the permafrost, coldness with litter oxygen, and fragile ecosystem. As the air temperature warms all over the world, the permafrost on the plateau responds quickly. The average temperature of permafrost is up by 0.2―0.3℃ in recent 20 years, and the island-permafrost dwindles with a high rate, and the high temperature permafrost degrades quickly, and the temperature of the low temperature permafrost increases remarkably. These gradually cause the highway engineering diseases in the permafrost region. The Qinghai-Tibet highway has experienced much maintenance and rebuilding for 50 years after it was built, and the continual observation and investigation have been made for more than 30 years. This road is the longest test engineering for permafrost research work in China. It is no doubt that it is also the greatest engineering project in plateau permafrost region. The Ministry of Communication in China initiated the research project "Research on a series of technologies for highway constructing in the permafrost regions" in 2002, which was to meet the challenges from the effect of climatic warming on the permafrost. The project systematically studied the permafrost engineering theories, methods for survey and design, engineering stabilization measures, preventing of the road disasters and maintaining, environment protection and the techniques to prolong the road

  17. Development of highway constructing technology in the permafrost region on the Qinshai-Tibet plateau

    Institute of Scientific and Technical Information of China (English)

    WANG ShuangJie; CHEN JianBing; ZHANG JinZhao; LI ZhuLong

    2009-01-01

    The Qinghai-Tibet Highway passes through the Qinghai-Tibet plateau hinterland from north to south, from Kunlun Mountain to Tanggula Mountain. The average altitude is above 4500 m and permafrost covers more than 700 km length of area with high elevation and high temperature. The climate of the plateau is capricious and the surroundings along the road are bad, where the mean annual atmosphere temperature is -2 to -7℃ and the oxygen content is inadequate, which is less than 50% of the sea level, while the solar radiation is higher than 3600 kJ/m2. The basic characteristics of the plateau surround-ings are the permafrost, coldness with litter oxygen, and fragile ecosystem. As the air temperature warms all over the world, the permafrost on the plateau responds quickly. The average temperature of permafrost is up by 0.2-0.3℃ in recent 20 years, and the island-permafrost dwindles with a high rate,and the high temperature permafrost degrades quickly, and the temperature of the low temperature permafrost increases remarkably. These gradually cause the highway engineering diseases in the permafrost region. The Qinghai-Tibet highway has experienced much maintenance and rebuilding for 50 years after it was built, and the continual observation and investigation have been made for more than 30 years. This road is the longest test engineering for permafrost research work in China. It is no doubt that it is also the greatest engineering project in plateau permafrost region. The Ministry of Communication in China initiated the research project "Research on a series of technologies for highway constructing in the permafrost regions" in 2002, which was to meet the challenges from the effect of climatic warming on the permafrost. The project systematically studied the permafrost engi- neering theories, methods for survey and design, engineering stabilization measures, preventing of the road disasters and maintaining, environment protection and the techniques to prolong the road

  18. Testing alternative models of climate-mediated extirpations

    Science.gov (United States)

    Beever, E.A.; Chris, R.A.Y.; Mote, P.W.; Wilkening, J.L.

    2010-01-01

    Biotic responses to climate change will vary among taxa and across latitudes, elevational gradients, and degrees of insularity. However, due to factors such as phenotypic plasticity, ecotypic variation, and evolved tolerance to thermal stress, it remains poorly understood whether losses should be greatest in populations experiencing the greatest climatic change or living in places where the prevailing climate is closest to the edge of the species' bioclimatic envelope (e.g., at the hottest, driest sites). Research on American pikas (Ochotona princeps) in montane areas of the Great Basin during 1994-1999 suggested that 20th-century population extirpations were predicted by a combination of biogeographic, anthropogenic, and especially climatic factors. Surveys during 2005-2007 documented additional extirpations and within-site shifts of pika distributions at remaining sites. To evaluate the evidence in support of alternative hypotheses involving effects of thermal stress on pikas, we placed temperature sensors at 156 locations within pika habitats in the vicinity of 25 sites with historical records of pikas in the Basin. We related these time series of sensor data to data on ambient temperature from weather stations within the Historical Climate Network. We then used these highly correlated relationships, combined with long-term data from the same weather stations, to hindcast temperatures within pika habitats from 1945 through 2006. To explain patterns of loss, we posited three alternative classes of direct thermal stress: (1) acute cold stress (number of days below a threshold temperature); (2) acute heat stress (number of days above a threshold, temperature); and. (3) chronic heat stress (average summer temperature). Climate change was defined as change in our thermal metrics between two 31-y.r periods: 1945-1975 and 1976-2006. We found that patterns of persistence were well predicted by metrics of climate. Our best models suggest some effects of climate change

  19. Distribution of a climate-sensitive species at an interior range margin

    Science.gov (United States)

    Ray, Chris; Beever, Erik; Rodhouse, Thomas J.

    2016-01-01

    Advances in understanding the factors that limit a species’ range, particularly in the context of climate change, have come disproportionately through investigations at range edges or margins. The margins of a species’ range might often correspond with anomalous microclimates that confer habitat suitability where the species would otherwise fail to persist. We addressed this hypothesis using data from an interior, climatic range margin of the American pika (Ochotona princeps), an indicator of relatively cool, mesic climates in rocky habitats of western North America. Pikas in Lava Beds National Monument, northeastern California, USA, occur at elevations much lower than predicted by latitude and longitude. We hypothesized that pika occurrence within Lava Beds would be associated primarily with features such as “ice caves” in which sub-surface ice persists outside the winter months. We used data loggers to monitor sub-surface temperatures at cave entrances and at non-cave sites, confirming that temperatures were cooler and more stable at cave entrances. We surveyed habitat characteristics and evidence of pika occupancy across a random sample of cave and non-cave sites over a 2-yr period. Pika detection probability was high (~0.97), and the combined occupancy of cave and non-cave sites varied across the 2 yr from 27% to 69%. Contrary to our hypothesis, occupancy was not higher at cave sites. Vegetation metrics were the best predictors of site use by pikas, followed by an edge effect and elevation. The importance of vegetation as a predictor of pika distribution at this interior range margin is congruent with recent studies from other portions of the species’ range. However, we caution that vegetation composition depends on microclimate, which might be the proximal driver of pika distribution. The microclimates available in non-cave crevices accessible to small animals have not been characterized adequately for lava landscapes. We advocate innovation in the

  20. A China-Japan Cooperative JICA Atmospheric Observing Network over the Tibetan Plateau (JICA/Tibet Project): An Overviews

    National Research Council Canada - National Science Library

    ZHANG, Renhe; KOIKE, Toshio; XU, Xiangde; MA, Yaoming; YANG, Kun

    2012-01-01

    ... constructed an integrated atmospheric observing system, especially for the water vapor observation, across the Tibetan Plateau and its adjacent areas during the period of 2005-2009 under the JICA...

  1. The fractional acoustoelectric current plateau induced by the energy-dependent tunnelling from dynamic quantum dots into an impurity dot

    Science.gov (United States)

    Chen, S. W.; Song, L.

    2016-08-01

    The fractional acoustoelectric (AE) current plateau in surface-acoustic-waves (SAW) single-electron transport devices is studied by measuring the current plateau as a function of the SAW power and gate bias as well as a function of perpendicular magnetic filed. Our investigation indicates that the fractional plateau is induced by the tunnelling effect from the dynamic quantum dots (QDs) into a static impurity dot. Rate equations are used to extract the tunnelling rates, which change a lot with the number of electrons in the dynamic QDs, the SAW power and gate bias. In addition, the current plateau evolves into a fractional structure, when a strong perpendicular magnetic field is applied to the system.

  2. The structure contours of the Calico sequence boundary in the Kaiparowits Plateau, southern Utah (csbstrc*g)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This is a polygon coverage of the structure contours of the Calico sequence boundary in the Kaiparowits Plateau, southern Utah. Sequence boundary elevations are...

  3. Coal fields and outlines of coal-bearing strata in the Colorado Plateau coal assessment study area (cpcf*g)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These are shapefiles and ARC/INFO coverages of coal fields and coal-bearing formations in the Colorado Plateau. These GIS layers were created by combining numerous...

  4. Coal-mine production history from 1984 through 1995 in the Colorado Plateau coal assessment study area (cpmphg)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This is a point coverage containing 12 years (1984 through 1995) of coal mining history in the Colorado Plateau coal assessment study area. This layer was derived...

  5. Soil bacterial communities shaped by geochemical factors and land use in a less-explored area, Tibetan Plateau

    National Research Council Canada - National Science Library

    Guan, Xiangyu; Wang, Jinfeng; Zhao, Hui; Wang, Jianjun; Luo, Ximing; Liu, Fei; Zhao, Fangqing

    2013-01-01

    As the largest low-latitude permafrost region, the Tibetan Plateau (TP) is an important part of the earth's terrestrial ecosystem and one of the most vulnerable areas to climate change and human activities...

  6. Accumulation and erosion of aeolian sediments in the northeastern Qinghai-Tibetan Plateau and implications for provenance to the Chinese Loess Plateau

    Science.gov (United States)

    Liu, Xiang-Jun; Xiao, Guoqiao; E, Chongyi; Li, Xiangzhong; Lai, Zhongping; Yu, Lupeng; Wang, Zhong

    2017-03-01

    The northern and northeastern Qinghai-Tibetan Plateau (QTP) is regarded as one important source region of the Chinese Loess Plateau (CLP). However, how the fine grain sediments in this region were transported to the CLP remains debatable. In this study, we dated aeolian sediments, alluviums, beach sediments, and sand wedges in the northeastern QTP using optical dating, combined with previously reported ages, explored the aeolian sediment deposition patterns in this region. The dating results shown that aeolian sediments mainly accumulated during the marine isotope stage (MIS) 3 and since the last deglaciation, alluvial sediments mainly deposited during the middle to late MIS 3 (between ∼40 ka and 22 ka), and sand wedges formed during the MIS 4 and MIS 2 cold intervals. Based on the sedimentary stratigraphic characteristics and existing optical dating chronologies, we propose that fine grain sediments in the northern and northeastern QTP were eroded and carried to the CLP by westerly wind during last glacial and stadial cold stages. However, during last interglacial and interstadial warm stages, aeolian sediments deflated from western barren lands and deserts were mainly trapped in the northeastern QTP, and some were transported to the Alax arid zone or Yinchuan-Hetao plain by rivers that flow out of QTP, then transported to the CLP by northwesterly Asian winter monsoon (AWM). This cold stage westerly wind transport, warm stage rivers plus AWM transport pattern has existed at least since the late middle Pleistocene.

  7. Melt-Enhanced Rejuvenation of Lithospheric Mantle: Insights from the Colorado Plateau

    CERN Document Server

    Roy, Mousumi; Holtzman, Ben; Gaherty, James

    2012-01-01

    The stability of the lithospheric mantle beneath the ancient cratonic cores of continents is primarily a function of chemical modification during the process of melt extraction. Processes by which stable continental lithosphere may be destabilized are not well-understood, although destabilization by thickening and removal of negatively-buoyant lithospheric mantle in "delamination" events has been proposed in a number of tectonic settings. In this paper we explore an alternative process for destabilizing continents, namely, thermal and chemical modification during infiltration of metasomatic fluids and melts into the lithospheric column. We consider observations pertinent to the structure and evolution of the Colorado Plateau within the western United States to argue that the physical and chemical state of the margins of the plateau have been variably modified and destabilized by interaction with melts. In the melt-infiltration process explored here, the primary mechanism for weakening and rejuvenating the pla...

  8. High Voltage Plateau and Data Reliability Test for the DSNC Troubleshooting

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kwang-June; Jeong, Jeong-Whan; Kang, Hee-Young; Shin, Hee-Sung; Kim, Ho-Dong [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2006-07-01

    DSNC(Dupic safeguard neutron counter) was installed in the Dupic fuel development facility (DFDF) for the nuclear material accounting in the end of 1990s and had operated normally until 2003. But there have been a problem after that time. It has an abnormal state in the function of counting the neutrons emitting from the Dupic process product as well as the spent nuclear fuel at present. In this study, high voltage plateau and data acquisition reliability test were carried out as a method of troubleshooting for DSNC. As a result of the test, it was confirmed that the high voltage plateau was not formed but data acquisition reliability was good at some high voltages and at 6V applied to the electronic circuit of the counter.

  9. Summer rainfall over the southwestern Tibetan Plateau controlled by deep convection over the Indian subcontinent.

    Science.gov (United States)

    Dong, Wenhao; Lin, Yanluan; Wright, Jonathon S; Ming, Yi; Xie, Yuanyu; Wang, Bin; Luo, Yong; Huang, Wenyu; Huang, Jianbin; Wang, Lei; Tian, Lide; Peng, Yiran; Xu, Fanghua

    2016-03-07

    Despite the importance of precipitation and moisture transport over the Tibetan Plateau for glacier mass balance, river runoff and local ecology, changes in these quantities remain highly uncertain and poorly understood. Here we use observational data and model simulations to explore the close relationship between summer rainfall variability over the southwestern Tibetan Plateau (SWTP) and that over central-eastern India (CEI), which exists despite the separation of these two regions by the Himalayas. We show that this relationship is maintained primarily by 'up-and-over' moisture transport, in which hydrometeors and moisture are lifted by convective storms over CEI and the Himalayan foothills and then swept over the SWTP by the mid-tropospheric circulation, rather than by upslope flow over the Himalayas. Sensitivity simulations confirm the importance of up-and-over transport at event scales, and an objective storm classification indicates that this pathway accounts for approximately half of total summer rainfall over the SWTP.

  10. Changes in Climate Extremes and Catastrophic Events in the Mongolian Plateau from 1951 to 2012

    DEFF Research Database (Denmark)

    Wang, Lei; Yao, Zhi-Jun; Jiang, Liguang;

    2016-01-01

    The spatiotemporal changes in 21 indices of extreme temperature and precipitation for the Mongolian Plateau from 1951 to 2012 were investigated on the basis of daily temperature and precipitation data from 70 meteorological stations. Changes in catastrophic events, such as droughts, floods...... was shown for total precipitation from west to east as based on the spatial distribution of decadal trends. Drought was the most serious extreme disaster, and prolonged drought for longer than 3 yr occurred about every 7-11 yr. An increasing trend in the disaster area was apparent for flood events from 1951......, and snowstorms, were also investigated for the same period. The correlations between catastrophic events and the extreme indices were examined. The results show that the Mongolian Plateau experienced an asymmetric warming trend. Both the cold extremes and warm extremes showed greater warming at night than...

  11. Rise and Demise of a Southern Laramide Hinterland Plateau, US-Mexico Border Region

    Science.gov (United States)

    Lawton, T. F.; Clinkscales, C. A.; Jennings, G. R.

    2011-12-01

    New U-Pb geochronology and stratigraphic data sets suggest that an elevated, altiplano-like plateau existed in the backarc region of what is now southern Arizona and southern New Mexico during Late Cretaceous through Paleogene (~28 Ma) time, and indicate that the Laramide province of the US was thus flanked on both its western and southern sides by hinterland plateaus. The Laramide stratigraphic record of southwestern New Mexico and southeastern Arizona formed during a short time period spanning 75-70 Ma, as indicated by numerous, newly-dated, interbedded tuff beds. The Laramide deposits (Fort Crittenden Formation of Arizona, Ringbone and Skunk Ranch Formations of Arizona, Cabullona Group of Sonora), which contain growth strata developed adjacent to steep thrust faults, accumulated in lake and lake-margin fan-delta and alluvial-fan settings on the northern margin of a volcanic arc whose main magmatic locus lay in northeastern Sonora and northwestern Chihuahua. By the end of basin development, the arc had migrated northward to occupy the former depocenters, such that intermediate volcanic rocks interfinger with and overlie the lacustrine deposits, and subvolcanic plutons, one with an age of 69 Ma, intrude and cross-cut thrust faults. Laramide strata unconformably overlie lowermost Upper Cretaceous (~97 Ma) strata and contractional structures are unconformably truncated beneath Oligocene (~33 Ma) volcaniclastic rocks. Detritus derived from the Cretaceous arc is abundant in Campanian fluvial strata (Kaiparowits Formation and Mesaverde Group) of the southern Colorado Plateau. East-west normal faults with as much as 3 km of displacement and a related array of conjugate NW- and NE-striking normal faults, many of these previously interpreted as reverse and transcurrent faults, are widespread in ranges of southern New Mexico and southeastern Arizona. These faults post-date Laramide contractional structures and are in turn cut by Neogene N-S normal faults. The east

  12. Microplastic pollution of lakeshore sediments from remote lakes in Tibet plateau, China.

    Science.gov (United States)

    Zhang, Kai; Su, Jing; Xiong, Xiong; Wu, Xiang; Wu, Chenxi; Liu, Jiantong

    2016-12-01

    Tibetan Plateau is known as the world's third pole, which is characterized by a low population density with very limited human activities. Tibetan Plateau possesses the greatest numbers of high-altitude inland lakes in the world. However, no information is currently available on the characteristic of microplastic pollution in those lakes within this remote area. In this work, lakeshore sediments from four lakes within the Siling Co basin in northern Tibet were sampled and examined for microplastics (plastic products. Polyethylene, polypropylene, polystyrene, polyethylene terephthalate, and polyvinyl chloride were identified from the microplastic samples using laser Raman spectroscopy, and oxidative and mechanical weathering textures were observed on the surface of microplastics using scanning electron microscope. These results demonstrate the presence of microplastics even for inland lakes in remote areas under very low human impact, and microplastic pollution can be a global issue.

  13. The age of the lithospheric mantle beneath the Northern Kerguelen Plateau

    Science.gov (United States)

    Debaille, V.; Mattielli, N. D.; Weis, D. A.

    2009-12-01

    The Kerguelen Plateau, in the Southern part of the Indian Ocean, provides a unique perspective on the building of Large Igneous Provinces. The Kerguelen Plateau by itself is divided in four parts, each presenting different geochemical characteristics that correspond to the various tectonic stages of the plateau evolution with time. The involvement of continental material has been evidenced in the Cretaceous lavas in the South of the plateau (>100 Myr). In contrast, there is no evidence for continental material in the young, Cenozoic lavas of the Kerguelen Archipelago, located in the Northern part of the plateau (NKP). On the other hand, the presence of subcontinental lithospheric material has been invoked in some basic and ultrabasic xenoliths from the archipelago [1]. These xenoliths, disseminated within alkaline lava series in the Southern and South-East part of the archipelago, have PT conditions generally comprised between 0.6 to 1.8 GPa (10-55 km) and 800 to 1000°C, corresponding to lithospheric conditions. Such petrogenetic conditions reflect underplated basaltic magmas and deep cumulates beneath the Kerguelen Plateau [2]. We have undertaken an Hf-Nd isotopic study on various xenoliths from the South East Province of the archipelago to decipher the fine structure of the mantle and the potential distribution of continental components under the NKP. Preliminary 143Nd/144Nd and 176Hf/177Hf results on websterite and spinel ± sapphirine bearing 2-pyroxenes metagabbro xenoliths show isotopic compositions overlapping those of the depleted ~29.5 Myr oldest lavas from the Archipelago (Mont Bureau). These lavas describe an isotopic alignment between the compositions of the South-East Indian Ridge and the flood basalts from Mont Crozier, which are representative of the enriched signature of the Kerguelen mantle plume. There is no evidence for contamination of the xenoliths from their host during their ascent. The xenoliths analyzed so far do not compare to the

  14. Discovery of C4 species at high altitude in Qinghai-Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    WANG Luo; L(U) Houyuan; WU Naiqin; CHU Duo; HAN Jiamao; WU Yuhu; WU Haibin; GU Zhaoyan

    2004-01-01

    Plant specimens are collected from the areas between latitude 27°42'N and 40°57'N, and longitude 88°93'E and 103°24'E, with an altitudinal range from 2210 to 5050 m above the sea level in Qinghai-Tibetan Plateau. The stable carbon isotope analysis indicates that two of Chenopodiaceae and six of Poaceae in the samples are C4 plants. Four of the C4 plants are found in 11 spots with altitudes above 3800 m,and Pennisetum centrasiaticum, Arundinella yunnanensis and Orinus thoroldii are present in six spots above 4000 m, even up to 4520 m. At low CO2 partial pressure, that sufficient energy of high light improving C4 plant's tolerance of low temperature and precipitations concentrating in growing season probably are favorable for C4 plants growing at high altitude in Qinghai-Tibetan Plateau.

  15. Conventional radiographic examination in the evaluation of sequelae after tibial plateau fractures

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, D.B.; Bjerg-Nielsen, A.; Laursen, N.

    1988-07-01

    Seventy patients with 72 conservatively treated tibial plateau fractures were re-examined after an average of 5 3/4 years. Among 55 fractured knees with a primary articular depression of 1-20 mm, the depression was still present radiographically in 47 knees. No correlation existed between the persistent radiographic depression and function of the knee. Moderate to severe osteoarthrosis was found in 10 knees; in five of these the osteoarthrosis was of clinical importance. More than 10 degrees of valgus/varus deformity was present in two knees. In two patients osteotomy had been performed to correct deformity. It is concluded that a persistent radiographic articular depression is of no clinical importance in tibial plateau fractures treated by conservative methods, which include early movement of the knee. The radiographic examination, however is, useful in the evaluation of valgus/varus deformity and osteoarthrosis.

  16. Discovery of the granulite xenoliths in Cenozoic volcanic rocks from Hoh Xil, Tibetan plateau

    Institute of Scientific and Technical Information of China (English)

    LAI Shaocong; YI Haisheng; LIN Jinhui

    2003-01-01

    Two-pyroxene granulite and clinopyroxene granulite xenoliths have been recently discovered in the Late Paleogene to Neogene volcanic rocks (with ages in the range of 4.27~44.60 Ma) that outcropped in Hoh Xil, central Tibetan plateau. Based on the electron microprobe analysis data, the xenoliths provide constraints for the formation equilibrium temperatures of the two-pyroxene granulite being about 783 to 818 ℃ as determined by two-pyroxene thermometry and the forming pressure of the clinopyroxene granulite being about 0.845 to 0.858 GPa that is equivalent to 27.9~28.3 km depth respectively. It indicates that these granulite xenoliths represent the samples from the middle part of the thickened Tibetan crust. This discovery is important and significant to making further discussion on the component and thermal regime of the deep crust of the Tibetan plateau.

  17. Bayesian estimation of the Modified Omori Law parameters for the Iranian Plateau

    Science.gov (United States)

    Ommi, S.; Zafarani, H.; Smirnov, V. B.

    2016-07-01

    The forecasting of large aftershocks is a preliminary and critical step in seismic hazard analysis and seismic risk management. From a statistical point of view, it relies entirely on the estimation of the properties of aftershock sequences using a set of laws with well-defined parameters. Since the frequentist and Bayesian approaches are common tools to assess these parameter values, we compare the two approaches for the Modified Omori Law and a selection of mainshock-aftershock sequences in the Iranian Plateau. There is a general agreement between the two methods, but the Bayesian appears to be more efficient as the number of recorded aftershocks decreases. Taking into account temporal variations of the b-value, the slope of the frequency-size distribution, the probability for the occurrence of strong aftershock, or larger main shock has been calculated in a finite time window using the parameters of the Modified Omori Law observed in the Iranian Plateau.

  18. A Probe into the Dynamic Change of Land Use in the Southern Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    Bin; GUO; Li; ZHANG

    2013-01-01

    In order to reveal the characteristics of land use change in the south loess plateau,this paper tentatively divided Loess Plateau into North and South under the support of GIS,and then introduced land use spatial temporal dynamic model,analyzed land use dynamic change in provincial scale. The results showed: during the 25 years,construction land area increased from 3 555. 99 km2 to 4 794. 28 km2,unused land decreased by 0. 02 percentage points,forest land area increased from 51 011. 31 km2 to 51 066. 79 km2,waters increased of 0. 01 percentage points,farmland area decreased to 98 561. 57 km2 from 100 004. 79 km2,grassland area increased by 0.08 percentage points. Land use change important values in province scale on each were not identical,showed obvious regional differences.

  19. Social Facilities Provision And Rural Development Relationships On The Jos Plateau-Nigeria

    Directory of Open Access Journals (Sweden)

    Bala Dogo

    2013-07-01

    Full Text Available The study has measured the levels of social facilities provision in the rural areas of the Jos Plateau Region of Nigeria. Over 60 dependent and independent variables were employed in determining the rural development index (RUDEVI. Social sectors covered include health care, educational, water supply, rural roads, places of worship and other general welfare infrastructure and services. The various levels of rural development indices of the 86 communities studied were subjected to analysis of variances (ANOVA, correlation and regression using population size as the focal variable. It was found that population is not a major factor used in the sitting of social facilities in the rural areas of Jos Plateau, which is not supposed to be the case.

  20. One-Third Magnetization Plateau with a Preceding Novel Phase in Volborthite

    Science.gov (United States)

    Ishikawa, H.; Yoshida, M.; Nawa, K.; Jeong, M.; Krämer, S.; Horvatić, M.; Berthier, C.; Takigawa, M.; Akaki, M.; Miyake, A.; Tokunaga, M.; Kindo, K.; Yamaura, J.; Okamoto, Y.; Hiroi, Z.

    2015-06-01

    We have synthesized high-quality single crystals of volborthite, a seemingly distorted kagome antiferromagnet, and carried out high-field magnetization measurements up to 74 T and V 51 NMR measurements up to 30 T. An extremely wide 1 /3 magnetization plateau appears above 28 T and continues over 74 T at 1.4 K, which has not been observed in previous studies using polycrystalline samples. NMR spectra reveal an incommensurate order (most likely a spin-density wave order) below 22 T and a simple spin structure in the plateau phase. Moreover, a novel intermediate phase is found between 23 and 26 T, where the magnetization varies linearly with magnetic field and the NMR spectra indicate an inhomogeneous distribution of the internal magnetic field. This sequence of phases in volborthite bears a striking similarity to those of frustrated spin chains with a ferromagnetic nearest-neighbor coupling J1 competing with an antiferromagnetic next-nearest-neighbor coupling J2 .

  1. Pseudoarthrosis of medial tibial plateau fracture-role of alignment procedure

    Directory of Open Access Journals (Sweden)

    Devgan Ashish

    2013-04-01

    Full Text Available 【Abstract】 Nonunion in tibial plateau fractures is very rare. Limited literature is available on Pubmed search on intraarticular tibial nonunion. Most of the cases reported have been following failed surgical treatment and none was neglected fractures. Three patients of isolated and neglected medial tibial plateau nonunion with almost similar demo-graphic profile are reported in this paper. All the three pa-tients were managed by minimally invasive compression fixation using lag screws supplemented with limb realign-ment procedure of high tibial osteotomy. We discussed the injury mechanism, management and rehabilitation in such cases and reviewed the available literature regarding such a presentation. Key words: Fracture healing; Tibial fractures; Frac-ture fixation; Osteotomy

  2. PLATO - the next-generation AASTINO for robotic site-testing on the Antarctic plateau

    Science.gov (United States)

    Hengst, S.; Lawrence, J.; Luong-van, D.; Everett, J.; Ashley, M. C. B.; Storey, J. W. V.; Hall, S.

    2006-08-01

    A new site-testing facility, PLATO (Plateau Observatory), is under development at UNSW for deployment to remote sites on the Antarctic Plateau including Dome A. The new facility will adopt many of the features of the AASTINO (Automated Astrophysical Site Testing InterNational Observatory) facility at Dome C. PLATO will autonomously control a flexible site testing and observing instrument suite, monitored via the Iridium satellite network. A challenging aspect of PLATO is to maximise the reliability of the power source while minimising fuel consumption. We are building a low pressure, low temperature environmental chamber to simulate operation at the highest altitudes (4,100 m at Dome A). Two types of engines will be tested: a single-cylinder diesel engine and a Stirling engine.

  3. Loess Plateau check dams can potentially sequester eroded soil organic carbon

    Science.gov (United States)

    Zhang, Haicheng; Liu, Shuguang; Yuan, Wenping; Dong, Wenjie; Xia, Jiangzhou; Cao, Yaojun; Jia, Yanwei

    2016-06-01

    Check dams are special soil and water conservation structures in the Loess Plateau, China. They play an important role in intercepting sediments and soil organic carbon (SOC). However, the decomposition of intercepted SOC and the environmental regulations at check dams have not been investigated. We conducted several paired field experiments at both check dams and slope lands in the Yanhe Watershed of the Loess Plateau to examine the characteristics of SOC decomposition at check dams. On average, the SOC mineralization rate in slope lands was approximately three times higher than in check dams. Increased soil moisture and compaction in check dams can constrain carbon mineralization by limiting the oxygen availability of SOC and can isolate substrate carbon from heterotrophic microorganisms. Our results indicate that check dams display a considerable potential for eroded SOC sequestration via reducing the soil respiration rate and highlight the important implications of lateral carbon redistribution and human engineering projects when estimating regional or global ecosystem carbon cycles.

  4. Evolution of Chinese mammalian faunal regions and elevation of the Qinghai-Xizang (Tibet) Plateau

    Institute of Scientific and Technical Information of China (English)

    QIU Zhuding; LI Chuankui

    2005-01-01

    On the basis of mammal's high evolutionary rates and sensitivity to environment, this paper deals with the evolutionary history of the Chinese Cenozoic mammals and environmental changes, and explores the relationship between the uplift of the Qinghai-Xizang Plateau and the evolution of zoogeographic provinces of China, through studying fossil mammal and the lithological characters of fossil-bearing beds. Evolutionary tendency and distribution of the mammals demonstrate that the uplift of the Qinghai-Xizang region, onset of the Asian monsoon and differentiation of the mammalian distribution probably initiated in Oligocene. The elevation of the Plateau seems to be a gradual and relatively stable process, and the uplift not only has resulted in significant environmental changes in Asia, but also caused distinct regional differentiation of mammals in China since the middle Miocene, and as a consequence the modern zoogeographic provinces gradually took shape.

  5. Demonstration Research into Eco-environment Rehabilitation on the Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    Xu Mingxiang; Liu Guobin

    2002-01-01

    @@ As part of the "Action Plan for the Development of Western China," the project is conducted by the Institute of Soil & Water Conservation under CAS and the Ministry of Water Resources. It focuses on the rehabilitation of the regional eco-environment, such as a large-scale afforestation drive on enclosed hillsides, efforts to turn the reclaimed farmland on steep mountain slopes into woodland and pastureland, the greening of mountainous areas and speeding up the restoration tempo of the original vegetation on the Loess Plateau. An experiment & demonstration zone has been co-established by the CAS Institute and the provincial Government of Shaanxi. Located in a hillygully region sprawling in the heartland of the Plateau,the zone includes nine townships, covering 707 square kilometers in total area. Since its start in 2000, the project has scored remarkable progress:

  6. Circulation and its seasonal variability in region around the Kerguelen Plateau

    Institute of Scientific and Technical Information of China (English)

    Shi Jiuxin(史久新); Le Kentang(乐肯堂); Byung Ho Choi

    2002-01-01

    A coupled ice-ocean isopycnal numerical model of the Southern Ocean is established to study the circulation and its seasonal variability in the region around the Kerguelen Plateau. An analysis of the simulated results shows significant stripe-like structure and non-zonal feature of the Antarctic Circumpolar Current (ACC) in this region. ACC begins to bifurcate and to turn its direction before meeting the plateau. The southernmost branch of ACC is near to the Antarctic coast and displays its strong interaction with the westward Antarctic Slope Current. The northern branch of ACC has a tendency of annual variations while the southern one varies in a semiannual cycle. The variation phases of both branches are coincident with that of the wind stress in this region.

  7. Volcanic succession of the Borovnik Member (Mohorje Formation, Bloke Plateau area, Central Slovenia

    Directory of Open Access Journals (Sweden)

    Stevo Dozet

    2009-06-01

    Full Text Available A 75 m thick volcanic succession of the Borovnik Member, Mohorje Formation in the Bloke Plateau area consistsof dacitic and rhyolitic rocks deposited in a shallow-marine environment. Volcanic activity begun with lavaflows that underwent extensive disintegration, autobrecciation and mixing with the underlying unconsolidated fine-grained clastic sediments producing dacite/rhyolite-siltstone peperites. Peperites are very rich in fractured plagioclase phenocrysts, and owing to the incorporation of clastic material, they are commonly depleted in silica.The overlying fining-upward pyroclastic sequence is monotonous. Basal parts mainly consist of coarse-grained vitric tuffs that may contain some smaller pumice lapilli. The overlying volcaniclastics are fine-grained vitric tuffs,and in the uppermost parts of the sequence, they are interbedded with cherts.The study confirms the existence of primary volcaniclastic succession in the Bloke Plateau area and excludes its epiclastic or reworked origin.

  8. Water quality in the Tibetan Plateau: Metal contents of four selected rivers

    Energy Technology Data Exchange (ETDEWEB)

    Huang Xiang [Laboratory of Applied Environmental Chemistry, University of Kuopio, Patteristonkatu 1, FIN-50100 Mikkeli (Finland); Department of Chemistry and Environmental Sciences, Tibet University, No. 36 Jiangsu Lu, Lhasa, T.A.R. 850000 (China)], E-mail: xiang.huang@uku.fi; Sillanpaeae, Mika [Laboratory of Applied Environmental Chemistry, University of Kuopio, Patteristonkatu 1, FIN-50100 Mikkeli (Finland)], E-mail: mika.sillanpaa@uku.fi; Duo Bu [Department of Chemistry and Environmental Sciences, Tibet University, No. 36 Jiangsu Lu, Lhasa, T.A.R. 850000 (China)], E-mail: pudorr@yahoo.com.cn; Gjessing, Egil T. [Department of Chemistry, University of Oslo, P.O. Box 1033, Oslo 0315 (Norway)], E-mail: egil.gjessing@kjemi.uio.no

    2008-11-15

    The water used by 85% of the Asian population originates in Tibetan Plateau. During April and May of 2006, water samples were collected from four major Asian rivers in the Plateau (i.e. the Salween, Mekong, Yangtze River and Yarlung Tsangpo) and analyzed for Cu, Pb, Zn, Ag, Mo, Cd, Co, Cr, Ni, Li, Mn, Al, Fe, Mg and Hg. The results showed that elements such as Mg were rather high in Tibetan rivers, giving a mean electrical conductance of 36 mS/m. In a few locations, the results also showed relatively high concentrations of Al and Fe (>1 mg/L). However, the concentrations of Cu, Zn, Ag, Cd, and Cr were generally low. Contamination with Pb was identified at a few locations in the Salween and Ni at a few sites in the Yangtze River. - For the first time, total dissolved metal contents in source water of four major Asian rivers were evaluated at the same time.

  9. Ground motion parameters of Shillong plateau: One of the most seismically active zones of northeastern India

    Institute of Scientific and Technical Information of China (English)

    Saurabh Baruah; Santanu Baruah; Naba Kumar Gogoi; Olga Erteleva; Felix Aptikaev; J.R.Kayal

    2009-01-01

    Strong ground motion parameters for Shillong plateau of northeastern India are examined. Empirical relations are obtained for main parameters of ground motions as a function of earthquake magnitude, fault type, source depth, velocity characterization of medium and distance. Correlation between ground motion parameters and characteristics of seismogenic zones are established. A new attenuation relation for peak ground acceleration is developed, which predicts higher expected PGA in the region. Parameters of strong motions, particularly the predominant periods and duration of vibrations, depend on the morphology of the studied area. The study measures low estimates of logarithmic width in Shillong plateau. The attenuation relation estimated for pulse width critically indicates increased pulse width dependence on the logarithmic distance which accounts for geometrical spreading and anelastic attenuation.